Update supported VS versions in INSTALL.md

tools/db_bench_tool.cc use uint64_t instead of size_t (#9800 )
Summary: to fix compilation for 32bit Pull Request resolved: https://github.com/facebook/rocksdb/pull/9800 Reviewed By: riversand963 Differential Revision: D35404447 fbshipit-source-id: 6a1185bb38f3a718357aa120e3b26a1ea77f023d
2026-07-07 22:55:23 +08:00 · 2022-04-08 14:37:12 -07:00 · 2022-04-08 13:29:19 -07:00 · 2022-04-07 12:25:43 -07:00 · 2022-04-07 10:31:50 -07:00 · 2022-04-06 18:36:23 -07:00
1071 changed files with 116150 additions and 37959 deletions
@@ -1,54 +0,0 @@
-#! /bin/bash
-
-# Work around issue with parallel make output causing random error, as in
-# make[1]: write error: stdout
-# Probably due to a kernel bug:
-#   https://bugs.launchpad.net/ubuntu/+source/linux-signed/+bug/1814393
-# Seems to affect image ubuntu-1604:201903-01 and ubuntu-1604:202004-01
-
-cd "$(dirname $0)"
-
-if [ ! -x cat_ignore_eagain.out ]; then
-    cc -x c -o cat_ignore_eagain.out - << EOF
-#include <unistd.h>
-#include <errno.h>
-#include <stdio.h>
-int main() {
-    int n, m, p;
-    char buf[1024];
-    for (;;) {
-        n = read(STDIN_FILENO, buf, 1024);
-        if (n > 0 && n <= 1024) {
-            for (m = 0; m < n;) {
-                p = write(STDOUT_FILENO, buf + m, n - m);
-                if (p < 0) {
-                    if (errno == EAGAIN) {
-                        // ignore but pause a bit
-                        usleep(100);
-                    } else {
-                        perror("write failed");
-                        return 42;
-                    }
-                } else {
-                    m += p;
-                }
-            }
-        } else if (n < 0) {
-            if (errno == EAGAIN) {
-                // ignore but pause a bit
-                usleep(100);
-            } else {
-                // Some non-ignorable error
-                perror("read failed");
-                return 43;
-            }
-        } else {
-            // EOF
-            return 0;
-        }
-    }
-}
-EOF
-fi
-
-exec ./cat_ignore_eagain.out
@@ -5,18 +5,11 @@ orbs:
  slack: circleci/slack@3.4.2

 aliases:
-  - &notify-on-master-failure
+  - &notify-on-main-failure
    fail_only: true
-    only_for_branches: master
+    only_for_branches: main

 commands:
-  install-pyenv-on-macos:
-    steps:
-      - run:
-          name: Install pyenv on macos
-          command: |
-            HOMEBREW_NO_AUTO_UPDATE=1 brew install pyenv
-
  install-cmake-on-macos:
    steps:
      - run:
@@ -24,6 +17,13 @@ commands:
          command: |
            HOMEBREW_NO_AUTO_UPDATE=1 brew install cmake

+  install-jdk8-on-macos:
+    steps:
+      - run:
+          name: Install JDK 8 on macos
+          command: |
+            brew install --cask adoptopenjdk/openjdk/adoptopenjdk8
+
  increase-max-open-files-on-macos:
    steps:
      - run:
@@ -34,30 +34,30 @@ commands:
            sudo launchctl limit maxfiles 1048576

  pre-steps:
-    parameters:
-      python-version:
-        default: "3.5.9"
-        type: string
    steps:
      - checkout
-      - run: pyenv install --skip-existing <<parameters.python-version>>
-      - run: pyenv global <<parameters.python-version>>
      - run:
          name: Setup Environment Variables
          command: |
            echo "export GTEST_THROW_ON_FAILURE=0" >> $BASH_ENV
            echo "export GTEST_OUTPUT=\"xml:/tmp/test-results/\"" >> $BASH_ENV
            echo "export SKIP_FORMAT_BUCK_CHECKS=1" >> $BASH_ENV
-            echo "export PRINT_PARALLEL_OUTPUTS=1" >> $BASH_ENV
+            echo "export GTEST_COLOR=1" >> $BASH_ENV
+            echo "export CTEST_OUTPUT_ON_FAILURE=1" >> $BASH_ENV
+            echo "export CTEST_TEST_TIMEOUT=300" >> $BASH_ENV
+            echo "export ZLIB_DOWNLOAD_BASE=https://rocksdb-deps.s3.us-west-2.amazonaws.com/pkgs/zlib" >> $BASH_ENV
+            echo "export BZIP2_DOWNLOAD_BASE=https://rocksdb-deps.s3.us-west-2.amazonaws.com/pkgs/bzip2" >> $BASH_ENV
+            echo "export SNAPPY_DOWNLOAD_BASE=https://rocksdb-deps.s3.us-west-2.amazonaws.com/pkgs/snappy" >> $BASH_ENV
+            echo "export LZ4_DOWNLOAD_BASE=https://rocksdb-deps.s3.us-west-2.amazonaws.com/pkgs/lz4" >> $BASH_ENV
+            echo "export ZSTD_DOWNLOAD_BASE=https://rocksdb-deps.s3.us-west-2.amazonaws.com/pkgs/zstd" >> $BASH_ENV

  pre-steps-macos:
      steps:
-        - pre-steps:
-            python-version: "3.6.0"
+        - pre-steps

  post-steps:
    steps:
-      - slack/status: *notify-on-master-failure
+      - slack/status: *notify-on-main-failure
      - store_test_results: # store test result if there's any
          path: /tmp/test-results
      - store_artifacts: # store LOG for debugging if there's any
@@ -76,11 +76,23 @@ commands:
      - run:
          name: Install Clang 10
          command: |
-            echo "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main" | sudo tee -a /etc/apt/sources.list
-            echo "deb-src http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main" | sudo tee -a /etc/apt/sources.list
+            wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+            echo "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main" | sudo tee -a /etc/apt/sources.list
+            echo "deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main" | sudo tee -a /etc/apt/sources.list
            echo "APT::Acquire::Retries \"10\";" | sudo tee -a /etc/apt/apt.conf.d/80-retries # llvm.org unreliable
            sudo apt-get update -y && sudo apt-get install -y clang-10

+  install-clang-13:
+    steps:
+      - run:
+          name: Install Clang 13
+          command: |
+            echo "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-13 main" | sudo tee -a /etc/apt/sources.list
+            echo "deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-13 main" | sudo tee -a /etc/apt/sources.list
+            echo "APT::Acquire::Retries \"10\";" | sudo tee -a /etc/apt/apt.conf.d/80-retries # llvm.org unreliable
+            wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
+            sudo apt-get update -y && sudo apt-get install -y clang-13
+
  install-gflags:
    steps:
      - run:
@@ -88,6 +100,27 @@ commands:
          command: |
            sudo apt-get update -y && sudo apt-get install -y libgflags-dev

+  install-benchmark:
+    steps:
+      - run:
+          name: Install ninja build
+          command: sudo apt-get update -y && sudo apt-get install -y ninja-build
+      - run:
+          name: Install benchmark
+          command: |
+            git clone --depth 1 --branch v1.6.1 https://github.com/google/benchmark.git ~/benchmark
+            cd ~/benchmark && mkdir build && cd build
+            cmake .. -GNinja -DCMAKE_BUILD_TYPE=Release -DBENCHMARK_ENABLE_GTEST_TESTS=0
+            ninja && sudo ninja install
+
+  upgrade-cmake:
+    steps:
+      - run:
+          name: Upgrade cmake
+          command: |
+            sudo apt remove --purge cmake
+            sudo snap install cmake --classic
+
  install-gflags-on-macos:
    steps:
      - run:
@@ -110,6 +143,21 @@ commands:
          command: |
            sudo apt-get update -y && sudo apt-get install -y libsnappy-dev zlib1g-dev libbz2-dev liblz4-dev libzstd-dev

+  install-libprotobuf-mutator:
+    steps:
+      - run:
+          name: Install libprotobuf-mutator libs
+          command: |
+            git clone --single-branch --branch master --depth 1 git@github.com:google/libprotobuf-mutator.git ~/libprotobuf-mutator
+            cd ~/libprotobuf-mutator && mkdir build && cd build
+            cmake .. -GNinja -DCMAKE_C_COMPILER=clang-13 -DCMAKE_CXX_COMPILER=clang++-13 -DCMAKE_BUILD_TYPE=Release -DLIB_PROTO_MUTATOR_DOWNLOAD_PROTOBUF=ON
+            ninja && sudo ninja install
+      - run:
+          name: Setup environment variables
+          command: |
+            echo "export PKG_CONFIG_PATH=/usr/local/OFF/:~/libprotobuf-mutator/build/external.protobuf/lib/pkgconfig/" >> $BASH_ENV
+            echo "export PROTOC_BIN=~/libprotobuf-mutator/build/external.protobuf/bin/protoc" >> $BASH_ENV
+
 executors:
  windows-2xlarge:
    machine:
@@ -120,229 +168,311 @@ executors:
 jobs:
  build-macos:
    macos:
-      xcode: 9.4.1
+      xcode: 12.5.1
+    resource_class: large
+    environment:
+      ROCKSDB_DISABLE_JEMALLOC: 1 # jemalloc cause env_test hang, disable it for now
    steps:
      - increase-max-open-files-on-macos
-      - install-pyenv-on-macos
      - install-gflags-on-macos
      - pre-steps-macos
-      - run: ulimit -S -n 1048576 && OPT=-DCIRCLECI make V=1 J=32 -j32 check | .circleci/cat_ignore_eagain
+      - run: ulimit -S -n 1048576 && OPT=-DCIRCLECI make V=1 J=32 -j32 all
      - post-steps

  build-macos-cmake:
    macos:
-      xcode: 9.4.1
+      xcode: 12.5.1
+    resource_class: large
+    parameters:
+      run_even_tests:
+        description: run even or odd tests, used to split tests to 2 groups
+        type: boolean
+        default: true
    steps:
      - increase-max-open-files-on-macos
-      - install-pyenv-on-macos
      - install-cmake-on-macos
      - install-gflags-on-macos
      - pre-steps-macos
-      - run: ulimit -S -n 1048576 && (mkdir build && cd build && cmake -DWITH_GFLAGS=0 .. && make V=1 -j32) | .circleci/cat_ignore_eagain
+      - run:
+          name: "cmake generate project file"
+          command: ulimit -S -n 1048576 && mkdir build && cd build && cmake -DWITH_GFLAGS=1 ..
+      - run:
+          name: "Build tests"
+          command: cd build && make V=1 -j32
+      - when:
+          condition: << parameters.run_even_tests >>
+          steps:
+            - run:
+                name: "Run even tests"
+                command: ulimit -S -n 1048576 && cd build && ctest -j32 -I 0,,2
+      - when:
+          condition:
+            not: << parameters.run_even_tests >>
+          steps:
+            - run:
+                name: "Run odd tests"
+                command: ulimit -S -n 1048576 && cd build && ctest -j32 -I 1,,2
      - post-steps

  build-linux:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
      - install-gflags
-      - run: make V=1 J=32 -j32 check | .circleci/cat_ignore_eagain
-      - post-steps
-
-  build-linux-mem-env:
-    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: 2xlarge
-    steps:
-      - pre-steps
-      - install-gflags
-      - run: MEM_ENV=1 make V=1 J=32 -j32 check | .circleci/cat_ignore_eagain
+      - run: make V=1 J=32 -j32 check
      - post-steps

  build-linux-encrypted-env:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
      - install-gflags
-      - run: ENCRYPTED_ENV=1 make V=1 J=32 -j32 check | .circleci/cat_ignore_eagain
+      - run: ENCRYPTED_ENV=1 make V=1 J=32 -j32 check
      - post-steps

  build-linux-shared_lib-alt_namespace-status_checked:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
      - install-gflags
-      - run: ASSERT_STATUS_CHECKED=1 TEST_UINT128_COMPAT=1 ROCKSDB_MODIFY_NPHASH=1 LIB_MODE=shared OPT="-DROCKSDB_NAMESPACE=alternative_rocksdb_ns" make V=1 -j32 check | .circleci/cat_ignore_eagain
+      - run: ASSERT_STATUS_CHECKED=1 TEST_UINT128_COMPAT=1 ROCKSDB_MODIFY_NPHASH=1 LIB_MODE=shared OPT="-DROCKSDB_NAMESPACE=alternative_rocksdb_ns" make V=1 -j32 check
      - post-steps

  build-linux-release:
    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: large
+      image: ubuntu-2004:202111-02
+    resource_class: 2xlarge
    steps:
      - checkout # check out the code in the project directory
-      - run: make V=1 -j8 release | .circleci/cat_ignore_eagain
+      - run: make V=1 -j32 release
      - run: if ./db_stress --version; then false; else true; fi # ensure without gflags
      - install-gflags
-      - run: make V=1 -j8 release | .circleci/cat_ignore_eagain
+      - run: make V=1 -j32 release
      - run: ./db_stress --version # ensure with gflags
      - post-steps

  build-linux-release-rtti:
    machine:
-      image: ubuntu-1604:201903-01
-    resource_class: large
+      image: ubuntu-2004:202111-02
+    resource_class: xlarge
    steps:
      - checkout # check out the code in the project directory
      - run: make clean
-      - run: USE_RTTI=1 DEBUG_LEVEL=0 make V=1 -j8 static_lib tools db_bench | .circleci/cat_ignore_eagain
+      - run: USE_RTTI=1 DEBUG_LEVEL=0 make V=1 -j16 static_lib tools db_bench
      - run: if ./db_stress --version; then false; else true; fi # ensure without gflags
      - run: sudo apt-get update -y && sudo apt-get install -y libgflags-dev
      - run: make clean
-      - run: USE_RTTI=1 DEBUG_LEVEL=0 make V=1 -j8 static_lib tools db_bench | .circleci/cat_ignore_eagain
+      - run: USE_RTTI=1 DEBUG_LEVEL=0 make V=1 -j16 static_lib tools db_bench
      - run: ./db_stress --version # ensure with gflags

  build-linux-lite:
    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: 2xlarge
+      image: ubuntu-2004:202111-02
+    resource_class: large
    steps:
      - pre-steps
      - install-gflags
-      - run: LITE=1 make V=1 J=32 -j32 check | .circleci/cat_ignore_eagain
+      - run: LITE=1 make V=1 J=8 -j8 check
      - post-steps

  build-linux-lite-release:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: large
    steps:
      - checkout # check out the code in the project directory
-      - run: LITE=1 make V=1 -j8 release | .circleci/cat_ignore_eagain
+      - run: LITE=1 make V=1 -j8 release
      - run: if ./db_stress --version; then false; else true; fi # ensure without gflags
      - install-gflags
-      - run: LITE=1 make V=1 -j8 release | .circleci/cat_ignore_eagain
+      - run: LITE=1 make V=1 -j8 release
      - run: ./db_stress --version # ensure with gflags
      - post-steps

  build-linux-clang-no_test_run:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: xlarge
    steps:
      - checkout # check out the code in the project directory
-      - run: sudo apt-get update -y && sudo apt-get install -y clang libgflags-dev
-      - run: CC=clang CXX=clang++ USE_CLANG=1 PORTABLE=1 make V=1 -j16 all | .circleci/cat_ignore_eagain
+      - run: sudo apt-get update -y && sudo apt-get install -y clang libgflags-dev libtbb-dev
+      - run: CC=clang CXX=clang++ USE_CLANG=1 PORTABLE=1 make V=1 -j16 all
      - post-steps

  build-linux-clang10-asan:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
      - install-gflags
      - install-clang-10
-      - run: COMPILE_WITH_ASAN=1 CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check | .circleci/cat_ignore_eagain # aligned new doesn't work for reason we haven't figured out
+      - run: ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check # aligned new doesn't work for reason we haven't figured out
      - post-steps

  build-linux-clang10-mini-tsan:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
+    # find test list by `make list_all_tests`
+    parameters:
+      start_test:
+        default: ""
+        type: string
+      end_test:
+        default: ""
+        type: string
    steps:
      - pre-steps
      - install-gflags
      - install-clang-10
-      - run: COMPILE_WITH_TSAN=1 CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check | .circleci/cat_ignore_eagain # aligned new doesn't work for reason we haven't figured out.
+      - install-gtest-parallel
+      - run:
+          name: "Build unit tests"
+          command: |
+            echo "env: $(env)"
+            ROCKSDBTESTS_START=<<parameters.start_test>> ROCKSDBTESTS_END=<<parameters.end_test>> ROCKSDBTESTS_SUBSET_TESTS_TO_FILE=/tmp/test_list COMPILE_WITH_TSAN=1 CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 --output-sync=target build_subset_tests
+      - run:
+          name: "Run unit tests in parallel"
+          command: |
+            sed -i 's/[[:space:]]*$//; s/ / \.\//g; s/.*/.\/&/' /tmp/test_list
+            cat /tmp/test_list
+            gtest-parallel $(</tmp/test_list) --output_dir=/tmp | cat  # pipe to cat to continuously output status on circleci UI. Otherwise, no status will be printed while the job is running.
      - post-steps

  build-linux-clang10-ubsan:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
      - install-gflags
      - install-clang-10
-      - run: COMPILE_WITH_UBSAN=1 OPT="-fsanitize-blacklist=.circleci/ubsan_suppression_list.txt" CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 ubsan_check | .circleci/cat_ignore_eagain # aligned new doesn't work for reason we haven't figured out
+      - run: COMPILE_WITH_UBSAN=1 OPT="-fsanitize-blacklist=.circleci/ubsan_suppression_list.txt" CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 ubsan_check # aligned new doesn't work for reason we haven't figured out
      - post-steps

  build-linux-clang10-clang-analyze:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
      - install-gflags
      - install-clang-10
      - run: sudo apt-get update -y && sudo apt-get install -y clang-tools-10
-      - run: CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 CLANG_ANALYZER="/usr/bin/clang++-10" CLANG_SCAN_BUILD=scan-build-10 USE_CLANG=1 make V=1 -j32 analyze | .circleci/cat_ignore_eagain # aligned new doesn't work for reason we haven't figured out. For unknown, reason passing "clang++-10" as CLANG_ANALYZER doesn't work, and we need a full path.
+      - run: CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 CLANG_ANALYZER="/usr/bin/clang++-10" CLANG_SCAN_BUILD=scan-build-10 USE_CLANG=1 make V=1 -j32 analyze # aligned new doesn't work for reason we haven't figured out. For unknown, reason passing "clang++-10" as CLANG_ANALYZER doesn't work, and we need a full path.
      - post-steps

-  build-linux-cmake-no_test_run:
+  build-linux-cmake:
    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: large
+      image: ubuntu-2004:202111-02
+    resource_class: 2xlarge
    steps:
-      - checkout # check out the code in the project directory
-      - run: (mkdir build && cd build && cmake -DWITH_GFLAGS=0 .. && make V=1 -j8) | .circleci/cat_ignore_eagain
+      - pre-steps
+      - install-gflags
+      - upgrade-cmake
+      - run: (mkdir build && cd build && cmake -DWITH_GFLAGS=1 .. && make V=1 -j20 && ctest -j20)
      - post-steps

-  build-linux-unity:
+  build-linux-cmake-ubuntu-20:
+    machine:
+      image: ubuntu-2004:202111-02
+    resource_class: 2xlarge
+    steps:
+      - pre-steps
+      - install-gflags
+      - install-benchmark
+      - run: (mkdir build && cd build && cmake -DWITH_GFLAGS=1 -DWITH_BENCHMARK=1 .. && make V=1 -j20 && ctest -j20)
+      - post-steps
+
+  build-linux-unity-and-headers:
    docker: # executor type
      - image: gcc:latest
    resource_class: large
    steps:
      - checkout # check out the code in the project directory
      - run: apt-get update -y && apt-get install -y libgflags-dev
-      - run: TEST_TMPDIR=/dev/shm && make V=1 -j8 unity_test | .circleci/cat_ignore_eagain
+      - run: TEST_TMPDIR=/dev/shm && make V=1 -j8 unity_test
+      - run: make V=1 -j8 -k check-headers # could be moved to a different build
      - post-steps

-  build-linux-gcc-4_8-no_test_run:
+  build-linux-gcc-7:
    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: large
+      image: ubuntu-2004:202111-02
+    resource_class: 2xlarge
    steps:
      - pre-steps
-      - run: sudo apt-get update -y && sudo apt-get install gcc-4.8 g++-4.8 libgflags-dev
-      - run: CC=gcc-4.8 CXX=g++-4.8 V=1 SKIP_LINK=1 make -j8 all | .circleci/cat_ignore_eagain # Linking broken because libgflags compiled with newer ABI
+      - run: sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test && sudo apt-get update -y && sudo apt-get install gcc-7 g++-7 libgflags-dev
+      - run: CC=gcc-7 CXX=g++-7 V=1 make -j32 check
      - post-steps

  build-linux-gcc-8-no_test_run:
    machine:
-      image: ubuntu-2004:202010-01
-    resource_class: large
+      image: ubuntu-2004:202111-02
+    resource_class: xlarge
    steps:
      - pre-steps
-      - run: sudo apt-get update -y && sudo apt-get install gcc-8 g++-8 libgflags-dev
-      - run: CC=gcc-8 CXX=g++-8 V=1 SKIP_LINK=1 make -j8 all | .circleci/cat_ignore_eagain # Linking broken because libgflags compiled with newer ABI
-      - post-steps
-
-  build-linux-gcc-9-no_test_run:
-    machine:
-      image: ubuntu-2004:202010-01
-    resource_class: large
-    steps:
-      - pre-steps
-      - run: sudo apt-get update -y && sudo apt-get install gcc-9 g++-9 libgflags-dev
-      - run: CC=gcc-9 CXX=g++-9 V=1 SKIP_LINK=1 make -j8 all | .circleci/cat_ignore_eagain # Linking broken because libgflags compiled with newer ABI
+      - run: sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test && sudo apt-get update -y && sudo apt-get install gcc-8 g++-8 libgflags-dev
+      - run: CC=gcc-8 CXX=g++-8 V=1 make -j16 all
      - post-steps

  build-linux-gcc-10-cxx20-no_test_run:
    machine:
-      image: ubuntu-2004:202010-01
+      image: ubuntu-2004:202111-02
    resource_class: xlarge
    steps:
      - pre-steps
      - run: sudo apt-get update -y && sudo apt-get install gcc-10 g++-10 libgflags-dev
-      - run: CC=gcc-10 CXX=g++-10 V=1 SKIP_LINK=1 ROCKSDB_CXX_STANDARD=c++20 make -j16 all | .circleci/cat_ignore_eagain # Linking broken because libgflags compiled with newer ABI
+      - run: CC=gcc-10 CXX=g++-10 V=1 ROCKSDB_CXX_STANDARD=c++20 make -j16 all
+      - post-steps
+
+  build-linux-gcc-11-no_test_run:
+    machine:
+      image: ubuntu-2004:202111-02
+    resource_class: xlarge
+    steps:
+      - pre-steps
+      - run: sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test && sudo apt-get update -y && sudo apt-get install gcc-11 g++-11 libgflags-dev
+      - install-benchmark
+      - run: CC=gcc-11 CXX=g++-11 V=1 make -j16 all microbench
+      - post-steps
+
+  build-linux-clang-13-no_test_run:
+    machine:
+      image: ubuntu-2004:202111-02
+    resource_class: xlarge
+    steps:
+      - pre-steps
+      - install-clang-13
+      - install-benchmark
+      - run: CC=clang-13 CXX=clang++-13 USE_CLANG=1 make -j16 all microbench
+      - post-steps
+
+  # This job is only to make sure the microbench tests are able to run, the benchmark result is not meaningful as the CI host is changing.
+  build-linux-run-microbench:
+    machine:
+      image: ubuntu-2004:202111-02
+    resource_class: 2xlarge
+    steps:
+      - pre-steps
+      - install-benchmark
+      - run: DEBUG_LEVEL=0 make -j32 run_microbench
+      - post-steps
+
+  build-linux-mini-crashtest:
+    machine:
+      image: ubuntu-2004:202111-02
+    resource_class: large
+    steps:
+      - pre-steps
+      - install-gflags
+      - install-compression-libs
+      - run: make V=1 -j8 CRASH_TEST_EXT_ARGS=--duration=960 blackbox_crash_test_with_atomic_flush
      - post-steps

  build-windows:
@@ -380,6 +510,8 @@ jobs:
              echo "Installing VS2015..."
              powershell .circleci/vs2015_install.ps1
            fi
+      - store_artifacts:
+          path: \Users\circleci\AppData\Local\Temp\vslogs.zip
      - run:
          name: "Install thirdparty dependencies"
          command: |
@@ -413,7 +545,7 @@ jobs:

  build-linux-java:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: large
    environment:
      JAVA_HOME: /usr/lib/jvm/java-1.8.0-openjdk-amd64
@@ -427,17 +559,14 @@ jobs:
            echo 'export PATH=$JAVA_HOME/bin:$PATH' >> $BASH_ENV
            which java && java -version
            which javac && javac -version
-      - run:
-          name: "Build RocksDBJava Shared Library"
-          command: make V=1 J=8 -j8 rocksdbjava | .circleci/cat_ignore_eagain
      - run:
          name: "Test RocksDBJava"
-          command: make V=1 J=8 -j8 jtest | .circleci/cat_ignore_eagain
+          command: make V=1 J=8 -j8 jtest
      - post-steps

  build-linux-java-static:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: large
    environment:
      JAVA_HOME: /usr/lib/jvm/java-1.8.0-openjdk-amd64
@@ -453,19 +582,20 @@ jobs:
            which javac && javac -version
      - run:
          name: "Build RocksDBJava Static Library"
-          command: make V=1 J=8 -j8 rocksdbjavastatic | .circleci/cat_ignore_eagain
+          command: make V=1 J=8 -j8 rocksdbjavastatic
      - post-steps

  build-macos-java:
    macos:
-      xcode: 9.4.1
-    resource_class: medium
+      xcode: 12.5.1
+    resource_class: large
    environment:
-      JAVA_HOME: /Library/Java/JavaVirtualMachines/jdk1.8.0_172.jdk/Contents/Home
+      JAVA_HOME: /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home
+      ROCKSDB_DISABLE_JEMALLOC: 1 # jemalloc causes java 8 crash
    steps:
      - increase-max-open-files-on-macos
-      - install-pyenv-on-macos
      - install-gflags-on-macos
+      - install-jdk8-on-macos
      - pre-steps-macos
      - run:
          name: "Set Java Environment"
@@ -474,25 +604,22 @@ jobs:
            echo 'export PATH=$JAVA_HOME/bin:$PATH' >> $BASH_ENV
            which java && java -version
            which javac && javac -version
-      - run:
-          name: "Build RocksDBJava Shared Library"
-          command: make V=1 J=8 -j8 rocksdbjava | .circleci/cat_ignore_eagain
      - run:
          name: "Test RocksDBJava"
-          command: make V=1 J=8 -j8 jtest | .circleci/cat_ignore_eagain
+          command: make V=1 J=16 -j16 jtest
      - post-steps

  build-macos-java-static:
    macos:
-      xcode: 9.4.1
-    resource_class: medium
+      xcode: 12.5.1
+    resource_class: large
    environment:
-      JAVA_HOME: /Library/Java/JavaVirtualMachines/jdk1.8.0_172.jdk/Contents/Home
+      JAVA_HOME: /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home
    steps:
      - increase-max-open-files-on-macos
-      - install-pyenv-on-macos
      - install-gflags-on-macos
      - install-cmake-on-macos
+      - install-jdk8-on-macos
      - pre-steps-macos
      - run:
          name: "Set Java Environment"
@@ -502,13 +629,37 @@ jobs:
            which java && java -version
            which javac && javac -version
      - run:
-          name: "Build RocksDBJava Static Library"
-          command: make V=1 J=8 -j8 rocksdbjavastatic | .circleci/cat_ignore_eagain
+          name: "Build RocksDBJava x86 and ARM Static Libraries"
+          command: make V=1 J=16 -j16 rocksdbjavastaticosx
+      - post-steps
+
+  build-macos-java-static-universal:
+    macos:
+      xcode: 12.5.1
+    resource_class: large
+    environment:
+      JAVA_HOME: /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home
+    steps:
+      - increase-max-open-files-on-macos
+      - install-gflags-on-macos
+      - install-cmake-on-macos
+      - install-jdk8-on-macos
+      - pre-steps-macos
+      - run:
+          name: "Set Java Environment"
+          command: |
+            echo "JAVA_HOME=${JAVA_HOME}"
+            echo 'export PATH=$JAVA_HOME/bin:$PATH' >> $BASH_ENV
+            which java && java -version
+            which javac && javac -version
+      - run:
+          name: "Build RocksDBJava Universal Binary Static Library"
+          command: make V=1 J=16 -j16 rocksdbjavastaticosx_ub
      - post-steps

  build-examples:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: large
    steps:
      - pre-steps
@@ -516,13 +667,13 @@ jobs:
      - run:
          name: "Build examples"
          command: |
-            OPT=-DTRAVIS V=1 make -j4 static_lib && cd examples && make -j4 | ../.circleci/cat_ignore_eagain
+            OPT=-DTRAVIS V=1 make -j4 static_lib && cd examples && make -j4
      - post-steps

  build-cmake-mingw:
    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: 2xlarge
+      image: ubuntu-2004:202111-02
+    resource_class: large
    steps:
      - pre-steps
      - install-gflags
@@ -544,62 +695,45 @@ jobs:

  build-linux-non-shm:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
-    parameters:
-      start_test:
-        default: ""
-        type: string
-      end_test:
-        default: ""
-        type: string
+    environment:
+      TEST_TMPDIR: /tmp/rocksdb_test_tmp
    steps:
      - pre-steps
      - install-gflags
-      - install-gtest-parallel
-      - run:
-          name: "Build unit tests"
-          command: |
-            echo "env: $(env)"
-            echo "** done env"
-            ROCKSDBTESTS_START=<<parameters.start_test>> ROCKSDBTESTS_END=<<parameters.end_test>> ROCKSDBTESTS_SUBSET_TESTS_TO_FILE=/tmp/test_list make V=1 -j32 --output-sync=target build_subset_tests
-      - run:
-          name: "Run unit tests in parallel"
-          command: |
-            sed -i 's/[[:space:]]*$//; s/ / \.\//g; s/.*/.\/&/' /tmp/test_list
-            cat /tmp/test_list
-            export TEST_TMPDIR=/tmp/rocksdb_test_tmp
-            gtest-parallel $(</tmp/test_list) --output_dir=/tmp | cat  # pipe to cat to continuously output status on circleci UI. Otherwise, no status will be printed while the job is running.
+      - run: make V=1 -j32 check
      - post-steps

  build-linux-arm-test-full:
    machine:
-      image: ubuntu-2004:202101-01
+      image: ubuntu-2004:202111-02
    resource_class: arm.large
    steps:
      - pre-steps
      - install-gflags
-      - run: make V=1 J=4 -j4 check | .circleci/cat_ignore_eagain
+      - run: make V=1 J=4 -j4 check
      - post-steps

  build-linux-arm:
    machine:
-      image: ubuntu-2004:202101-01
+      image: ubuntu-2004:202111-02
    resource_class: arm.large
    steps:
      - pre-steps
      - install-gflags
-      - run: ROCKSDBTESTS_PLATFORM_DEPENDENT=only make V=1 J=4 -j4 all_but_some_tests check_some | .circleci/cat_ignore_eagain
+      - run: ROCKSDBTESTS_PLATFORM_DEPENDENT=only make V=1 J=4 -j4 all_but_some_tests check_some
      - post-steps

  build-linux-arm-cmake-no_test_run:
    machine:
-      image: ubuntu-2004:202101-01
+      image: ubuntu-2004:202111-02
    resource_class: arm.large
    environment:
      JAVA_HOME: /usr/lib/jvm/java-8-openjdk-arm64
    steps:
      - pre-steps
+      - install-gflags
      - run:
          name: "Set Java Environment"
          command: |
@@ -612,7 +746,7 @@ jobs:
          command: |
            mkdir build
            cd build
-            cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 ..
+            cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=1 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 ..
            make -j4
      - run:
          name: "Build Java with cmake"
@@ -620,13 +754,13 @@ jobs:
            rm -rf build
            mkdir build
            cd build
-            cmake -DJNI=1 -DCMAKE_BUILD_TYPE=Release -DWITH_GFLAGS=0 ..
+            cmake -DJNI=1 -DCMAKE_BUILD_TYPE=Release -DWITH_GFLAGS=1 ..
            make -j4 rocksdb rocksdbjni
      - post-steps

  build-format-compatible:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-2004:202111-02
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -641,14 +775,32 @@ jobs:
            tools/check_format_compatible.sh
      - post-steps

+  build-fuzzers:
+    machine:
+      image: ubuntu-2004:202111-02
+    resource_class: large
+    steps:
+      - pre-steps
+      - install-clang-13
+      - run: sudo apt-get update -y && sudo apt-get install -y cmake ninja-build binutils liblzma-dev libz-dev pkg-config autoconf libtool
+      - install-libprotobuf-mutator
+      - run:
+          name: "Build rocksdb lib"
+          command: CC=clang-13 CXX=clang++-13 USE_CLANG=1 make -j4 static_lib
+      - run:
+          name: "Build fuzzers"
+          command: cd fuzz && make sst_file_writer_fuzzer db_fuzzer db_map_fuzzer
+      - post-steps
+
 workflows:
  version: 2
  build-linux:
    jobs:
      - build-linux
-  build-linux-mem-env:
+  build-linux-cmake:
    jobs:
-      - build-linux-mem-env
+      - build-linux-cmake
+      - build-linux-cmake-ubuntu-20
  build-linux-encrypted-env:
    jobs:
      - build-linux-encrypted-env
@@ -672,16 +824,24 @@ workflows:
      - build-linux-clang10-asan
  build-linux-clang10-mini-tsan:
    jobs:
-      - build-linux-clang10-mini-tsan
+      - build-linux-clang10-mini-tsan:
+          start_test: ""
+          end_test: "env_test"
+      - build-linux-clang10-mini-tsan:
+          start_test: "env_test"
+          end_test: ""
  build-linux-clang10-ubsan:
    jobs:
      - build-linux-clang10-ubsan
  build-linux-clang10-clang-analyze:
    jobs:
      - build-linux-clang10-clang-analyze
-  build-linux-unity:
+  build-linux-unity-and-headers:
    jobs:
-      - build-linux-unity
+      - build-linux-unity-and-headers
+  build-linux-mini-crashtest:
+    jobs:
+      - build-linux-mini-crashtest
  build-windows-vs2019:
    jobs:
      - build-windows:
@@ -697,56 +857,41 @@ workflows:
          name: "build-windows-vs2017"
          vs_year: "2017"
          cmake_generator: "Visual Studio 15 Win64"
-  build-windows-vs2015:
-    jobs:
-      - build-windows:
-          name: "build-windows-vs2015"
-          vs_year: "2015"
-          cmake_generator: "Visual Studio 14 Win64"
  build-java:
    jobs:
      - build-linux-java
      - build-linux-java-static
      - build-macos-java
      - build-macos-java-static
+      - build-macos-java-static-universal
  build-examples:
    jobs:
      - build-examples
-  build-linux-non-shm:
-    jobs:
-      - build-linux-non-shm:
-          start_test: ""
-          end_test: "db_options_test" # make sure unique in src.mk
-      - build-linux-non-shm:
-          start_test: "db_options_test" # make sure unique in src.mk
-          end_test: "filename_test" # make sure unique in src.mk
-      - build-linux-non-shm:
-          start_test: "filename_test" # make sure unique in src.mk
-          end_test: "statistics_test" # make sure unique in src.mk
-      - build-linux-non-shm:
-          start_test: "statistics_test" # make sure unique in src.mk
-          end_test: ""
  build-linux-compilers-no_test_run:
    jobs:
      - build-linux-clang-no_test_run
-      - build-linux-cmake-no_test_run
-      - build-linux-gcc-4_8-no_test_run
+      - build-linux-clang-13-no_test_run
+      - build-linux-gcc-7
      - build-linux-gcc-8-no_test_run
-      - build-linux-gcc-9-no_test_run
      - build-linux-gcc-10-cxx20-no_test_run
+      - build-linux-gcc-11-no_test_run
      - build-linux-arm-cmake-no_test_run
  build-macos:
    jobs:
      - build-macos
-  build-macos-cmake:
-    jobs:
-      - build-macos-cmake
+      - build-macos-cmake:
+          run_even_tests: true
+      - build-macos-cmake:
+          run_even_tests: false
  build-cmake-mingw:
    jobs:
      - build-cmake-mingw
  build-linux-arm:
    jobs:
      - build-linux-arm
+  build-fuzzers:
+    jobs:
+      - build-fuzzers
  nightly:
    triggers:
      - schedule:
@@ -754,7 +899,9 @@ workflows:
          filters:
            branches:
              only:
-                - master
+                - main
    jobs:
      - build-format-compatible
      - build-linux-arm-test-full
+      - build-linux-run-microbench
+      - build-linux-non-shm
@@ -32,10 +32,13 @@ jobs:
    - name: Download clang-format-diff.py
      uses: wei/wget@v1
      with:
-        args: https://raw.githubusercontent.com/llvm/llvm-project/main/clang/tools/clang-format/clang-format-diff.py
+        args: https://raw.githubusercontent.com/llvm/llvm-project/release/12.x/clang/tools/clang-format/clang-format-diff.py

    - name: Check format
      run: VERBOSE_CHECK=1 make check-format

    - name: Compare buckify output
      run: make check-buck-targets
+
+    - name: Simple source code checks
+      run: make check-sources
@@ -5,6 +5,7 @@ os:
 arch:
  - arm64
  - ppc64le
+  - s390x
 compiler:
  - clang
  - gcc
@@ -42,23 +43,18 @@ env:
  - JOB_NAME=cmake-gcc9 # 3-5 minutes
  - JOB_NAME=cmake-gcc9-c++20 # 3-5 minutes
  - JOB_NAME=cmake-mingw # 3 minutes
-  - JOB_NAME=make-gcc4.8
-  - JOB_NAME=status_checked

 matrix:
  exclude:
  - os : linux
    arch: arm64
    env: JOB_NAME=cmake-mingw
-  - os : linux
-    arch: arm64
-    env: JOB_NAME=make-gcc4.8
  - os: linux
    arch: ppc64le
    env: JOB_NAME=cmake-mingw
  - os: linux
-    arch: ppc64le
-    env: JOB_NAME=make-gcc4.8
+    arch: s390x
+    env: JOB_NAME=cmake-mingw
  - os: linux
    compiler: clang
  - if: type = pull_request AND commit_message !~ /FULL_CI/
@@ -73,6 +69,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: TEST_GROUP=1
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: TEST_GROUP=1
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -81,6 +81,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: TEST_GROUP=2
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: TEST_GROUP=2
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -89,6 +93,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: TEST_GROUP=3
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: TEST_GROUP=3
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -97,6 +105,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: TEST_GROUP=4
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: TEST_GROUP=4
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -109,6 +121,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: JOB_NAME=java_test
+  - if: type = pull_request AND commit_message !~ /FULL_CI/ AND commit_message !~ /java/
+    os: linux
+    arch: s390x
+    env: JOB_NAME=java_test
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -117,6 +133,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: JOB_NAME=lite_build
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: JOB_NAME=lite_build
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -125,6 +145,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: JOB_NAME=examples
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: JOB_NAME=examples
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -133,6 +157,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: JOB_NAME=cmake-gcc8
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: JOB_NAME=cmake-gcc8
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -141,6 +169,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: JOB_NAME=cmake-gcc9
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: s390x
+    env: JOB_NAME=cmake-gcc9
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -149,16 +181,13 @@ matrix:
    os: linux
    arch: ppc64le
    env: JOB_NAME=cmake-gcc9-c++20
-  - if: type = pull_request AND commit_message !~ /FULL_CI/
-    os : linux
-    arch: arm64
-    env: JOB_NAME=status_checked
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os: linux
-    arch: ppc64le
-    env: JOB_NAME=status_checked
+    arch: s390x
+    env: JOB_NAME=cmake-gcc9-c++20

 install:
+  -  CC=gcc-7 && CXX=g++-7
  - if [ "${JOB_NAME}" == cmake-gcc8 ]; then
      sudo apt-get install -y g++-8 || exit $?;
      CC=gcc-8 && CXX=g++-8;
@@ -170,9 +199,8 @@ install:
  - if [ "${JOB_NAME}" == cmake-mingw ]; then
      sudo apt-get install -y mingw-w64 || exit $?;
    fi
-  - if [ "${JOB_NAME}" == make-gcc4.8 ]; then
-      sudo apt-get install -y g++-4.8 || exit $?;
-      CC=gcc-4.8 && CXX=g++-4.8;
+  - if [ "${CXX}" == "g++-7" ]; then
+      sudo apt-get install -y g++-7 || exit $?;
    fi
  - |
    if [[ "${JOB_NAME}" == cmake* ]]; then
@@ -202,21 +230,25 @@ before_script:
 script:
  - date; ${CXX} --version
  - if [ `command -v ccache` ]; then ccache -C; fi
+  - export MK_PARALLEL=4;
+    if [[ "$TRAVIS_CPU_ARCH" == s390x ]]; then
+      export MK_PARALLEL=1;
+    fi
  - case $TEST_GROUP in
    platform_dependent)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=only make -j4 all_but_some_tests check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=only make -j$MK_PARALLEL all_but_some_tests check_some
      ;;
    1)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_END=backupable_db_test make -j4 check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_END=backup_engine_test make -j$MK_PARALLEL check_some
      ;;
    2)
-      OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 make -j4 tools && OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=backupable_db_test ROCKSDBTESTS_END=db_universal_compaction_test make -j4 check_some
+      OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 make -j$MK_PARALLEL tools && OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=backup_engine_test ROCKSDBTESTS_END=db_universal_compaction_test make -j$MK_PARALLEL check_some
      ;;
    3)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=db_universal_compaction_test ROCKSDBTESTS_END=table_properties_collector_test make -j4 check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=db_universal_compaction_test ROCKSDBTESTS_END=table_properties_collector_test make -j$MK_PARALLEL check_some
      ;;
    4)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=table_properties_collector_test make -j4 check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=table_properties_collector_test make -j$MK_PARALLEL check_some
      ;;
    esac
  - case $JOB_NAME in
@@ -224,10 +256,10 @@ script:
      OPT=-DTRAVIS LIB_MODE=shared V=1 make rocksdbjava jtest
      ;;
    lite_build)
-      OPT='-DTRAVIS -DROCKSDB_LITE' LIB_MODE=shared V=1 make -j4 all
+      OPT='-DTRAVIS -DROCKSDB_LITE' LIB_MODE=shared V=1 make -j$MK_PARALLEL all
      ;;
    examples)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 make -j4 static_lib && cd examples && make -j4
+      OPT=-DTRAVIS LIB_MODE=shared V=1 make -j$MK_PARALLEL static_lib && cd examples && make -j$MK_PARALLEL
      ;;
    cmake-mingw)
      sudo update-alternatives --set x86_64-w64-mingw32-g++ /usr/bin/x86_64-w64-mingw32-g++-posix;
@@ -240,13 +272,7 @@ script:
          ;;
      esac

-      mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 .. && make -j4 && cd  .. && rm -rf build && mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j4 rocksdb rocksdbjni
-      ;;
-    make-gcc4.8)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 SKIP_LINK=1 make -j4 all && [ "Linking broken because libgflags compiled with newer ABI" ]
-      ;;
-    status_checked)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ASSERT_STATUS_CHECKED=1 make -j4 check_some
+      mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 .. && make -j$MK_PARALLEL && cd  .. && rm -rf build && mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j$MK_PARALLEL rocksdb rocksdbjni
      ;;
    esac
 notifications:
@@ -2,7 +2,7 @@
 #     This cmake build is for Windows 64-bit only.
 #
 # Prerequisites:
-#     You must have at least Visual Studio 2015 Update 3. Start the Developer Command Prompt window that is a part of Visual Studio installation.
+#     You must have at least Visual Studio 2019. Start the Developer Command Prompt window that is a part of Visual Studio installation.
 #     Run the build commands from within the Developer Command Prompt window to have paths to the compiler and runtime libraries set.
 #     You must have git.exe in your %PATH% environment variable.
 #
@@ -14,7 +14,7 @@
 #        cd build
 # 3. Run cmake to generate project files for Windows, add more options to enable required third-party libraries.
 #    See thirdparty.inc for more information.
-#        sample command: cmake -G "Visual Studio 15 Win64" -DCMAKE_BUILD_TYPE=Release -DWITH_GFLAGS=1 -DWITH_SNAPPY=1 -DWITH_JEMALLOC=1 -DWITH_JNI=1 ..
+#        sample command: cmake -G "Visual Studio 16 2019" -DCMAKE_BUILD_TYPE=Release -DWITH_GFLAGS=1 -DWITH_SNAPPY=1 -DWITH_JEMALLOC=1 -DWITH_JNI=1 ..
 # 4. Then build the project in debug mode (you may want to add /m[:<N>] flag to run msbuild in <N> parallel threads
 #                                          or simply /m to use all avail cores)
 #        msbuild rocksdb.sln
@@ -27,15 +27,16 @@
 #
 # Linux:
 #
-# 1. Install a recent toolchain such as devtoolset-3 if you're on a older distro. C++11 required.
+# 1. Install a recent toolchain if you're on a older distro. C++17 required (GCC >= 7, Clang >= 5)
 # 2. mkdir build; cd build
 # 3. cmake ..
 # 4. make -j

-cmake_minimum_required(VERSION 3.5.1)
+cmake_minimum_required(VERSION 3.10)

 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake/modules/")
 include(ReadVersion)
+include(GoogleTest)
 get_rocksdb_version(rocksdb_VERSION)
 project(rocksdb
  VERSION ${rocksdb_VERSION}
@@ -62,6 +63,7 @@ if(CCACHE_FOUND)
 endif(CCACHE_FOUND)

 option(WITH_JEMALLOC "build with JeMalloc" OFF)
+option(WITH_LIBURING "build with liburing" ON)
 option(WITH_SNAPPY "build with SNAPPY" OFF)
 option(WITH_LZ4 "build with lz4" OFF)
 option(WITH_ZLIB "build with zlib" OFF)
@@ -70,6 +72,12 @@ option(WITH_WINDOWS_UTF8_FILENAMES "use UTF8 as characterset for opening files,
 if (WITH_WINDOWS_UTF8_FILENAMES)
  add_definitions(-DROCKSDB_WINDOWS_UTF8_FILENAMES)
 endif()
+
+if ($ENV{CIRCLECI})
+  message(STATUS "Build for CircieCI env, a few tests may be disabled")
+  add_definitions(-DCIRCLECI)
+endif()
+
 # third-party/folly is only validated to work on Linux and Windows for now.
 # So only turn it on there by default.
 if(CMAKE_SYSTEM_NAME MATCHES "Linux|Windows")
@@ -84,7 +92,7 @@ else()
 endif()

 if( NOT DEFINED CMAKE_CXX_STANDARD )
-  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD 17)
 endif()

 include(CMakeDependentOption)
@@ -122,11 +130,11 @@ else()
        set(GFLAGS_LIB ${GFLAGS_TARGET})
      else()
        # Config with GFLAGS_LIBRARIES available since gflags 2.1.0
-        set(GFLAGS_LIB ${GFLAGS_LIBRARIES})
+        set(GFLAGS_LIB ${gflags_LIBRARIES})
      endif()
    else()
      find_package(gflags REQUIRED)
-        set(GFLAGS_LIB gflags::gflags)
+      set(GFLAGS_LIB gflags::gflags)
    endif()
    include_directories(${GFLAGS_INCLUDE_DIR})
    list(APPEND THIRDPARTY_LIBS ${GFLAGS_LIB})
@@ -210,8 +218,8 @@ if(MSVC)
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zi /nologo /EHsc /GS /Gd /GR /GF /fp:precise /Zc:wchar_t /Zc:forScope /errorReport:queue")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /FC /d2Zi+ /W4 /wd4127 /wd4800 /wd4996 /wd4351 /wd4100 /wd4204 /wd4324")
 else()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -W -Wextra -Wall")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers -Wno-strict-aliasing")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -W -Wextra -Wall -pthread")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers -Wno-strict-aliasing -Wno-invalid-offsetof")
  if(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64")
    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wstrict-prototypes")
  endif()
@@ -259,6 +267,13 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "arm64|aarch64|AARCH64")
  endif(HAS_ARMV8_CRC)
 endif(CMAKE_SYSTEM_PROCESSOR MATCHES "arm64|aarch64|AARCH64")

+if(CMAKE_SYSTEM_PROCESSOR MATCHES "s390x")
+  CHECK_C_COMPILER_FLAG("-march=native" HAS_S390X_MARCH_NATIVE)
+  if(HAS_S390X_MARCH_NATIVE)
+    message(STATUS " HAS_S390X_MARCH_NATIVE yes")
+  endif(HAS_S390X_MARCH_NATIVE)
+endif(CMAKE_SYSTEM_PROCESSOR MATCHES "s390x")
+
 option(PORTABLE "build a portable binary" OFF)
 option(FORCE_SSE42 "force building with SSE4.2, even when PORTABLE=ON" OFF)
 option(FORCE_AVX "force building with AVX, even when PORTABLE=ON" OFF)
@@ -284,12 +299,17 @@ if(PORTABLE)
    if(FORCE_AVX2)
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mavx2 -mbmi -mlzcnt")
    endif()
+    if(CMAKE_SYSTEM_PROCESSOR MATCHES "^s390x")
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=z196")
+    endif()
  endif()
 else()
  if(MSVC)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /arch:AVX2")
  else()
-    if(NOT CMAKE_SYSTEM_PROCESSOR MATCHES "^(powerpc|ppc)64" AND NOT HAS_ARMV8_CRC)
+    if(CMAKE_SYSTEM_PROCESSOR MATCHES "^s390x" AND NOT HAS_S390X_MARCH_NATIVE)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=z196")
+    elseif(NOT CMAKE_SYSTEM_PROCESSOR MATCHES "^(powerpc|ppc)64" AND NOT HAS_ARMV8_CRC)
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
    endif()
  endif()
@@ -301,7 +321,8 @@ if(NOT MSVC)
  set(CMAKE_REQUIRED_FLAGS "-msse4.2 -mpclmul")
 endif()

-CHECK_CXX_SOURCE_COMPILES("
+if (NOT PORTABLE OR FORCE_SSE42)
+  CHECK_CXX_SOURCE_COMPILES("
 #include <cstdint>
 #include <nmmintrin.h>
 #include <wmmintrin.h>
@@ -313,16 +334,17 @@ int main() {
  auto d = _mm_cvtsi128_si64(c);
 }
 " HAVE_SSE42)
-if(HAVE_SSE42)
-  add_definitions(-DHAVE_SSE42)
-  add_definitions(-DHAVE_PCLMUL)
-elseif(FORCE_SSE42)
-  message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
+  if(HAVE_SSE42)
+    add_definitions(-DHAVE_SSE42)
+    add_definitions(-DHAVE_PCLMUL)
+  elseif(FORCE_SSE42)
+    message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
+  endif()
 endif()

 # Check if -latomic is required or not
 if (NOT MSVC)
-  set(CMAKE_REQUIRED_FLAGS "--std=c++11")
+  set(CMAKE_REQUIRED_FLAGS "--std=c++17")
  CHECK_CXX_SOURCE_COMPILES("
 #include <atomic>
 std::atomic<uint64_t> x(0);
@@ -332,27 +354,25 @@ int main() {
  return 0;
 }
 " BUILTIN_ATOMIC)
-if (NOT BUILTIN_ATOMIC)
-  #TODO: Check if -latomic exists
-  list(APPEND THIRDPARTY_LIBS atomic)
+  if (NOT BUILTIN_ATOMIC)
+    #TODO: Check if -latomic exists
+    list(APPEND THIRDPARTY_LIBS atomic)
+  endif()
 endif()
+
+if (WITH_LIBURING)
+  find_package(uring)
+  if (uring_FOUND)
+    add_definitions(-DROCKSDB_IOURING_PRESENT)
+    list(APPEND THIRDPARTY_LIBS uring::uring)
+  endif()
 endif()

 # Reset the required flags
 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})

-CHECK_CXX_SOURCE_COMPILES("
-#if defined(_MSC_VER) && !defined(__thread)
-#define __thread __declspec(thread)
-#endif
-int main() {
-  static __thread int tls;
-  (void)tls;
-}
-" HAVE_THREAD_LOCAL)
-if(HAVE_THREAD_LOCAL)
-  add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)
-endif()
+# thread_local is part of C++11 and later (TODO: clean up this define)
+add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)

 option(WITH_IOSTATS_CONTEXT "Enable IO stats context" ON)
 if (NOT WITH_IOSTATS_CONTEXT)
@@ -385,7 +405,7 @@ endif()

 option(WITH_TSAN "build with TSAN" OFF)
 if(WITH_TSAN)
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=thread -pie")
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=thread -Wl,-pie")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=thread -fPIC")
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=thread -fPIC")
  if(WITH_JEMALLOC)
@@ -588,6 +608,11 @@ if(HAVE_AUXV_GETAUXVAL)
  add_definitions(-DROCKSDB_AUXV_GETAUXVAL_PRESENT)
 endif()

+check_cxx_symbol_exists(F_FULLFSYNC "fcntl.h" HAVE_FULLFSYNC)
+if(HAVE_FULLFSYNC)
+  add_definitions(-DHAVE_FULLFSYNC)
+endif()
+
 include_directories(${PROJECT_SOURCE_DIR})
 include_directories(${PROJECT_SOURCE_DIR}/include)
 if(WITH_FOLLY_DISTRIBUTED_MUTEX)
@@ -599,19 +624,26 @@ find_package(Threads REQUIRED)

 set(SOURCES
        cache/cache.cc
+        cache/cache_entry_roles.cc
+        cache/cache_key.cc
+        cache/cache_reservation_manager.cc
        cache/clock_cache.cc
        cache/lru_cache.cc
+        cache/lru_secondary_cache.cc
        cache/sharded_cache.cc
        db/arena_wrapped_db_iter.cc
+        db/blob/blob_fetcher.cc
        db/blob/blob_file_addition.cc
        db/blob/blob_file_builder.cc
        db/blob/blob_file_cache.cc
        db/blob/blob_file_garbage.cc
        db/blob/blob_file_meta.cc
        db/blob/blob_file_reader.cc
+        db/blob/blob_garbage_meter.cc
        db/blob/blob_log_format.cc
        db/blob/blob_log_sequential_reader.cc
        db/blob/blob_log_writer.cc
+        db/blob/prefetch_buffer_collection.cc
        db/builder.cc
        db/c.cc
        db/column_family.cc
@@ -680,11 +712,11 @@ set(SOURCES
        env/env.cc
        env/env_chroot.cc
        env/env_encryption.cc
-        env/env_hdfs.cc
        env/file_system.cc
        env/file_system_tracer.cc
        env/fs_remap.cc
        env/mock_env.cc
+        env/unique_id_gen.cc
        file/delete_scheduler.cc
        file/file_prefetch_buffer.cc
        file/file_util.cc
@@ -703,6 +735,7 @@ set(SOURCES
        memory/concurrent_arena.cc
        memory/jemalloc_nodump_allocator.cc
        memory/memkind_kmem_allocator.cc
+        memory/memory_allocator.cc
        memtable/alloc_tracker.cc
        memtable/hash_linklist_rep.cc
        memtable/hash_skiplist_rep.cc
@@ -778,6 +811,7 @@ set(SOURCES
        table/table_factory.cc
        table/table_properties.cc
        table/two_level_iterator.cc
+        table/unique_id.cc
        test_util/sync_point.cc
        test_util/sync_point_impl.cc
        test_util/testutil.cc
@@ -789,12 +823,16 @@ set(SOURCES
        tools/ldb_tool.cc
        tools/sst_dump_tool.cc
        tools/trace_analyzer_tool.cc
-        trace_replay/trace_replay.cc
        trace_replay/block_cache_tracer.cc
        trace_replay/io_tracer.cc
+        trace_replay/trace_record_handler.cc
+        trace_replay/trace_record_result.cc
+        trace_replay/trace_record.cc
+        trace_replay/trace_replay.cc
        util/coding.cc
        util/compaction_job_stats_impl.cc
        util/comparator.cc
+        util/compression.cc
        util/compression_context_cache.cc
        util/concurrent_task_limiter_impl.cc
        util/crc32c.cc
@@ -811,25 +849,31 @@ set(SOURCES
        util/thread_local.cc
        util/threadpool_imp.cc
        util/xxhash.cc
-        utilities/backupable/backupable_db.cc
+        utilities/backup/backup_engine.cc
        utilities/blob_db/blob_compaction_filter.cc
        utilities/blob_db/blob_db.cc
        utilities/blob_db/blob_db_impl.cc
        utilities/blob_db/blob_db_impl_filesnapshot.cc
        utilities/blob_db/blob_dump_tool.cc
        utilities/blob_db/blob_file.cc
+        utilities/cache_dump_load.cc
+        utilities/cache_dump_load_impl.cc
        utilities/cassandra/cassandra_compaction_filter.cc
        utilities/cassandra/format.cc
        utilities/cassandra/merge_operator.cc
        utilities/checkpoint/checkpoint_impl.cc
+        utilities/compaction_filters.cc
        utilities/compaction_filters/remove_emptyvalue_compactionfilter.cc
+        utilities/counted_fs.cc
        utilities/debug.cc
        utilities/env_mirror.cc
        utilities/env_timed.cc
        utilities/fault_injection_env.cc
        utilities/fault_injection_fs.cc
+        utilities/fault_injection_secondary_cache.cc
        utilities/leveldb_options/leveldb_options.cc
        utilities/memory/memory_util.cc
+        utilities/merge_operators.cc
        utilities/merge_operators/bytesxor.cc
        utilities/merge_operators/max.cc
        utilities/merge_operators/put.cc
@@ -849,6 +893,7 @@ set(SOURCES
        utilities/simulator_cache/sim_cache.cc
        utilities/table_properties_collectors/compact_on_deletion_collector.cc
        utilities/trace/file_trace_reader_writer.cc
+        utilities/trace/replayer_impl.cc
        utilities/transactions/lock/lock_manager.cc
        utilities/transactions/lock/point/point_lock_tracker.cc
        utilities/transactions/lock/point/point_lock_manager.cc
@@ -867,6 +912,7 @@ set(SOURCES
        utilities/transactions/write_unprepared_txn.cc
        utilities/transactions/write_unprepared_txn_db.cc
        utilities/ttl/db_ttl_impl.cc
+        utilities/wal_filter.cc
        utilities/write_batch_with_index/write_batch_with_index.cc
        utilities/write_batch_with_index/write_batch_with_index_internal.cc)

@@ -884,6 +930,31 @@ list(APPEND SOURCES
  utilities/transactions/lock/range/range_tree/lib/util/dbt.cc
  utilities/transactions/lock/range/range_tree/lib/util/memarena.cc)

+message(STATUS "ROCKSDB_PLUGINS: ${ROCKSDB_PLUGINS}")
+if ( ROCKSDB_PLUGINS )
+  string(REPLACE " " ";" PLUGINS ${ROCKSDB_PLUGINS})
+  foreach (plugin ${PLUGINS})
+    add_subdirectory("plugin/${plugin}")
+    foreach (src ${${plugin}_SOURCES})
+      list(APPEND SOURCES plugin/${plugin}/${src})
+      set_source_files_properties(
+        plugin/${plugin}/${src}
+        PROPERTIES COMPILE_FLAGS "${${plugin}_COMPILE_FLAGS}")
+    endforeach()
+    foreach (path ${${plugin}_INCLUDE_PATHS})
+      include_directories(${path})
+    endforeach()
+    foreach (lib ${${plugin}_LIBS})
+      list(APPEND THIRDPARTY_LIBS ${lib})
+    endforeach()
+    foreach (link_path ${${plugin}_LINK_PATHS})
+      link_directories(AFTER ${link_path})
+    endforeach()
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${${plugin}_CMAKE_SHARED_LINKER_FLAGS}")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${${plugin}_CMAKE_EXE_LINKER_FLAGS}")
+  endforeach()
+endif()
+
 if(HAVE_SSE42 AND NOT MSVC)
  set_source_files_properties(
    util/crc32c.cc
@@ -907,13 +978,8 @@ if(WIN32)
    port/win/env_win.cc
    port/win/env_default.cc
    port/win/port_win.cc
-    port/win/win_logger.cc)
-  if(NOT MINGW)
-    # Mingw only supports std::thread when using
-    # posix threads.
-    list(APPEND SOURCES
-      port/win/win_thread.cc)
-  endif()
+    port/win/win_logger.cc
+    port/win/win_thread.cc)
 if(WITH_XPRESS)
  list(APPEND SOURCES
    port/win/xpress_win.cc)
@@ -946,12 +1012,6 @@ set(ROCKSDB_SHARED_LIB rocksdb-shared${ARTIFACT_SUFFIX})

 option(ROCKSDB_BUILD_SHARED "Build shared versions of the RocksDB libraries" ON)

-option(WITH_LIBRADOS "Build with librados" OFF)
-if(WITH_LIBRADOS)
-  list(APPEND SOURCES
-    utilities/env_librados.cc)
-  list(APPEND THIRDPARTY_LIBS rados)
-endif()

 if(WIN32)
  set(SYSTEM_LIBS ${SYSTEM_LIBS} shlwapi.lib rpcrt4.lib)
@@ -1095,23 +1155,29 @@ if(WITH_TESTS)
  )
  if(WITH_ALL_TESTS)
    list(APPEND TESTS
+        cache/cache_reservation_manager_test.cc
        cache/cache_test.cc
        cache/lru_cache_test.cc
+        cache/lru_secondary_cache_test.cc
+        db/blob/blob_counting_iterator_test.cc
        db/blob/blob_file_addition_test.cc
        db/blob/blob_file_builder_test.cc
        db/blob/blob_file_cache_test.cc
        db/blob/blob_file_garbage_test.cc
        db/blob/blob_file_reader_test.cc
+        db/blob/blob_garbage_meter_test.cc
        db/blob/db_blob_basic_test.cc
        db/blob/db_blob_compaction_test.cc
        db/blob/db_blob_corruption_test.cc
        db/blob/db_blob_index_test.cc
        db/column_family_test.cc
        db/compact_files_test.cc
+        db/compaction/clipping_iterator_test.cc
        db/compaction/compaction_job_stats_test.cc
        db/compaction/compaction_job_test.cc
        db/compaction/compaction_iterator_test.cc
        db/compaction/compaction_picker_test.cc
+        db/compaction/compaction_service_test.cc
        db/comparator_db_test.cc
        db/corruption_test.cc
        db/cuckoo_table_db_test.cc
@@ -1121,6 +1187,7 @@ if(WITH_TESTS)
        db/db_compaction_filter_test.cc
        db/db_compaction_test.cc
        db/db_dynamic_level_test.cc
+        db/db_encryption_test.cc
        db/db_flush_test.cc
        db/db_inplace_update_test.cc
        db/db_io_failure_test.cc
@@ -1135,6 +1202,7 @@ if(WITH_TESTS)
        db/db_options_test.cc
        db/db_properties_test.cc
        db/db_range_del_test.cc
+        db/db_rate_limiter_test.cc
        db/db_secondary_test.cc
        db/db_sst_test.cc
        db/db_statistics_test.cc
@@ -1146,6 +1214,7 @@ if(WITH_TESTS)
        db/db_universal_compaction_test.cc
        db/db_wal_test.cc
        db/db_with_timestamp_compaction_test.cc
+        db/db_write_buffer_manager_test.cc
        db/db_write_test.cc
        db/dbformat_test.cc
        db/deletefile_test.cc
@@ -1157,6 +1226,7 @@ if(WITH_TESTS)
        db/file_indexer_test.cc
        db/filename_test.cc
        db/flush_job_test.cc
+        db/import_column_family_test.cc
        db/listener_test.cc
        db/log_test.cc
        db/manual_compaction_test.cc
@@ -1190,7 +1260,7 @@ if(WITH_TESTS)
        logging/env_logger_test.cc
        logging/event_logger_test.cc
        memory/arena_test.cc
-        memory/memkind_kmem_allocator_test.cc
+        memory/memory_allocator_test.cc
        memtable/inlineskiplist_test.cc
        memtable/skiplist_test.cc
        memtable/write_buffer_manager_test.cc
@@ -1245,13 +1315,14 @@ if(WITH_TESTS)
        util/thread_list_test.cc
        util/thread_local_test.cc
        util/work_queue_test.cc
-        utilities/backupable/backupable_db_test.cc
+        utilities/backup/backup_engine_test.cc
        utilities/blob_db/blob_db_test.cc
        utilities/cassandra/cassandra_functional_test.cc
        utilities/cassandra/cassandra_format_test.cc
        utilities/cassandra/cassandra_row_merge_test.cc
        utilities/cassandra/cassandra_serialize_test.cc
        utilities/checkpoint/checkpoint_test.cc
+        utilities/env_timed_test.cc
        utilities/memory/memory_test.cc
        utilities/merge_operators/string_append/stringappend_test.cc
        utilities/object_registry_test.cc
@@ -1265,16 +1336,15 @@ if(WITH_TESTS)
        utilities/transactions/optimistic_transaction_test.cc
        utilities/transactions/transaction_test.cc
        utilities/transactions/lock/point/point_lock_manager_test.cc
+        utilities/transactions/write_committed_transaction_ts_test.cc
        utilities/transactions/write_prepared_transaction_test.cc
        utilities/transactions/write_unprepared_transaction_test.cc
        utilities/transactions/lock/range/range_locking_test.cc
        utilities/ttl/ttl_test.cc
+        utilities/util_merge_operators_test.cc
        utilities/write_batch_with_index/write_batch_with_index_test.cc
    )
  endif()
-  if(WITH_LIBRADOS)
-    list(APPEND TESTS utilities/env_librados_test.cc)
-  endif()

  if(WITH_FOLLY_DISTRIBUTED_MUTEX)
    list(APPEND TESTS third-party/folly/folly/synchronization/test/DistributedMutexTest.cpp)
@@ -1302,21 +1372,17 @@ if(WITH_TESTS)

  foreach(sourcefile ${TESTS})
      get_filename_component(exename ${sourcefile} NAME_WE)
-      add_executable(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX} ${sourcefile})
-      set_target_properties(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX}
+      add_executable(${exename}${ARTIFACT_SUFFIX} ${sourcefile})
+      set_target_properties(${exename}${ARTIFACT_SUFFIX}
        PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
        EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
        EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
        OUTPUT_NAME ${exename}${ARTIFACT_SUFFIX}
      )
-      target_link_libraries(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} testharness gtest ${THIRDPARTY_LIBS} ${ROCKSDB_LIB})
+      target_link_libraries(${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} testharness gtest ${THIRDPARTY_LIBS} ${ROCKSDB_LIB})
      if(NOT "${exename}" MATCHES "db_sanity_test")
-        add_test(NAME ${exename} COMMAND ${exename}${ARTIFACT_SUFFIX})
-        add_dependencies(check ${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX})
-      endif()
-      if("${exename}" MATCHES "env_librados_test")
-        # env_librados_test.cc uses librados directly
-        target_link_libraries(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX} rados)
+        gtest_discover_tests(${exename} DISCOVERY_TIMEOUT 120)
+        add_dependencies(check ${exename}${ARTIFACT_SUFFIX})
      endif()
  endforeach(sourcefile ${TESTS})

@@ -1342,13 +1408,15 @@ endif()

 if(WITH_BENCHMARK_TOOLS)
  add_executable(db_bench${ARTIFACT_SUFFIX}
+    tools/simulated_hybrid_file_system.cc
    tools/db_bench.cc
    tools/db_bench_tool.cc)
  target_link_libraries(db_bench${ARTIFACT_SUFFIX}
    ${ROCKSDB_LIB} ${THIRDPARTY_LIBS})

  add_executable(cache_bench${ARTIFACT_SUFFIX}
-    cache/cache_bench.cc)
+    cache/cache_bench.cc
+    cache/cache_bench_tool.cc)
  target_link_libraries(cache_bench${ARTIFACT_SUFFIX}
    ${ROCKSDB_LIB} ${GFLAGS_LIB})

@@ -1394,3 +1462,8 @@ option(WITH_EXAMPLES "build with examples" OFF)
 if(WITH_EXAMPLES)
  add_subdirectory(examples)
 endif()
+
+option(WITH_BENCHMARK "build benchmark tests" OFF)
+if(WITH_BENCHMARK)
+  add_subdirectory(${PROJECT_SOURCE_DIR}/microbench/)
+endif()
@@ -1,4 +1,4 @@
-# RocksDB default options change log
+# RocksDB default options change log (NO LONGER MAINTAINED)
 ## Unreleased
 * delayed_write_rate takes the rate given by rate_limiter if not specified.

@@ -6,7 +6,7 @@ than release mode.

 RocksDB's library should be able to compile without any dependency installed,
 although we recommend installing some compression libraries (see below).
-We do depend on newer gcc/clang with C++11 support.
+We do depend on newer gcc/clang with C++17 support (GCC >= 7, Clang >= 5).

 There are few options when compiling RocksDB:

@@ -47,10 +47,12 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi

 * If you wish to build the RocksJava static target, then cmake is required for building Snappy.

+* If you wish to run microbench (e.g, `make microbench`, `make ribbon_bench` or `cmake -DWITH_BENCHMARK=1`), Google benchmark >= 1.6.0 is needed.
+
 ## Supported platforms

 * **Linux - Ubuntu**
-    * Upgrade your gcc to version at least 4.8 to get C++11 support.
+    * Upgrade your gcc to version at least 7 to get C++17 support.
    * Install gflags. First, try: `sudo apt-get install libgflags-dev`
      If this doesn't work and you're using Ubuntu, here's a nice tutorial:
      (http://askubuntu.com/questions/312173/installing-gflags-12-04)
@@ -62,8 +64,7 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
    * Install zstandard: `sudo apt-get install libzstd-dev`.

 * **Linux - CentOS / RHEL**
-    * Upgrade your gcc to version at least 4.8 to get C++11 support:
-      `yum install gcc48-c++`
+    * Upgrade your gcc to version at least 7 to get C++17 support
    * Install gflags:

              git clone https://github.com/gflags/gflags.git
@@ -113,11 +114,11 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
              make && sudo make install

 * **OS X**:
-    * Install latest C++ compiler that supports C++ 11:
+    * Install latest C++ compiler that supports C++ 17:
        * Update XCode:  run `xcode-select --install` (or install it from XCode App's settting).
        * Install via [homebrew](http://brew.sh/).
            * If you're first time developer in MacOS, you still need to run: `xcode-select --install` in your command line.
-            * run `brew tap homebrew/versions; brew install gcc48 --use-llvm` to install gcc 4.8 (or higher).
+            * run `brew tap homebrew/versions; brew install gcc7 --use-llvm` to install gcc 7 (or higher).
    * run `brew install rocksdb`

 * **FreeBSD** (11.01):
@@ -160,7 +161,7 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi

    * Install the dependencies for RocksDB:

-        pkg_add gmake gflags snappy bzip2 lz4 zstd git jdk bash findutils gnuwatch 
+        pkg_add gmake gflags snappy bzip2 lz4 zstd git jdk bash findutils gnuwatch

    * Build RocksDB from source:

@@ -179,16 +180,15 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
 * **iOS**:
  * Run: `TARGET_OS=IOS make static_lib`. When building the project which uses rocksdb iOS library, make sure to define two important pre-processing macros: `ROCKSDB_LITE` and `IOS_CROSS_COMPILE`.

-* **Windows**:
-  * For building with MS Visual Studio 13 you will need Update 4 installed.
+* **Windows** (Visual Studio 2017 to up):
  * Read and follow the instructions at CMakeLists.txt
-  * Or install via [vcpkg](https://github.com/microsoft/vcpkg) 
+  * Or install via [vcpkg](https://github.com/microsoft/vcpkg)
       * run `vcpkg install rocksdb:x64-windows`

 * **AIX 6.1**
    * Install AIX Toolbox rpms with gcc
    * Use these environment variables:
-  
+
             export PORTABLE=1
             export CC=gcc
             export AR="ar -X64"
@@ -199,9 +199,9 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
             export LIBPATH=/opt/freeware/lib
             export JAVA_HOME=/usr/java8_64
             export PATH=/opt/freeware/bin:$PATH
-  
+
 * **Solaris Sparc**
-    * Install GCC 4.8.2 and higher.
+    * Install GCC 7 and higher.
    * Use these environment variables:

             export CC=gcc
@@ -210,4 +210,3 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
             export EXTRA_LDFLAGS=-m64
             export PORTABLE=1
             export PLATFORM_LDFLAGS="-static-libstdc++ -static-libgcc"
-
@@ -1,6 +1,6 @@
 This is the list of all known third-party language bindings for RocksDB. If something is missing, please open a pull request to add it.

-* Java - https://github.com/facebook/rocksdb/tree/master/java
+* Java - https://github.com/facebook/rocksdb/tree/main/java
 * Python
    * http://python-rocksdb.readthedocs.io/en/latest/
    * http://pyrocksdb.readthedocs.org/en/latest/ (unmaintained)
@@ -8,11 +8,7 @@

 BASH_EXISTS := $(shell which bash)
 SHELL := $(shell which bash)
-# Default to python3. Some distros like CentOS 8 do not have `python`.
-ifeq ($(origin PYTHON), undefined)
-	PYTHON := $(shell which python3 || which python || echo python3)
-endif
-export PYTHON
+include python.mk

 CLEAN_FILES = # deliberately empty, so we can append below.
 CFLAGS += ${EXTRA_CFLAGS}
@@ -134,12 +130,6 @@ CFLAGS +=  -DHAVE_POWER8
 HAVE_POWER8=1
 endif

-ifeq (,$(shell $(CXX) -fsyntax-only -march=armv8-a+crc+crypto -xc /dev/null 2>&1))
-CXXFLAGS += -march=armv8-a+crc+crypto
-CFLAGS += -march=armv8-a+crc+crypto
-ARMCRC_SOURCE=1
-endif
-
 # if we're compiling for shared libraries, add the shared flags
 ifeq ($(LIB_MODE),shared)
 CXXFLAGS += $(PLATFORM_SHARED_CFLAGS) -DROCKSDB_DLL
@@ -220,13 +210,8 @@ am__v_AR_ = $(am__v_AR_$(AM_DEFAULT_VERBOSITY))
 am__v_AR_0 = @echo "  AR      " $@;
 am__v_AR_1 =

-ifdef ROCKSDB_USE_LIBRADOS
-LIB_SOURCES += utilities/env_librados.cc
-LDFLAGS += -lrados
-endif
-
 AM_LINK = $(AM_V_CCLD)$(CXX) -L. $(patsubst lib%.a, -l%, $(patsubst lib%.$(PLATFORM_SHARED_EXT), -l%, $^)) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
-AM_SHARE = $(AM_V_CCLD) $(CXX) $(PLATFORM_SHARED_LDFLAGS)$@ -L. $(patsubst lib%.$(PLATFORM_SHARED_EXT), -l%, $^) $(LDFLAGS) -o $@
+AM_SHARE = $(AM_V_CCLD) $(CXX) $(PLATFORM_SHARED_LDFLAGS)$@ -L. $(patsubst lib%.$(PLATFORM_SHARED_EXT), -l%, $^) $(EXEC_LDFLAGS) $(LDFLAGS) -o $@

 # Detect what platform we're building on.
 # Export some common variables that might have been passed as Make variables
@@ -240,6 +225,7 @@ dummy := $(shell (export ROCKSDB_ROOT="$(CURDIR)"; \
                  export PORTABLE="$(PORTABLE)"; \
                  export ROCKSDB_NO_FBCODE="$(ROCKSDB_NO_FBCODE)"; \
                  export USE_CLANG="$(USE_CLANG)"; \
+                  export LIB_MODE="$(LIB_MODE)"; \
                  "$(CURDIR)/build_tools/build_detect_platform" "$(CURDIR)/make_config.mk"))
 # this file is generated by the previous line to set build flags and sources
 include make_config.mk
@@ -248,7 +234,40 @@ ROCKSDB_PLUGIN_MKS = $(foreach plugin, $(ROCKSDB_PLUGINS), plugin/$(plugin)/*.mk
 include $(ROCKSDB_PLUGIN_MKS)
 ROCKSDB_PLUGIN_SOURCES = $(foreach plugin, $(ROCKSDB_PLUGINS), $(foreach source, $($(plugin)_SOURCES), plugin/$(plugin)/$(source)))
 ROCKSDB_PLUGIN_HEADERS = $(foreach plugin, $(ROCKSDB_PLUGINS), $(foreach header, $($(plugin)_HEADERS), plugin/$(plugin)/$(header)))
-PLATFORM_LDFLAGS += $(foreach plugin, $(ROCKSDB_PLUGINS), $($(plugin)_LDFLAGS))
+ROCKSDB_PLUGIN_PKGCONFIG_REQUIRES = $(foreach plugin, $(ROCKSDB_PLUGINS), $($(plugin)_PKGCONFIG_REQUIRES))
+CXXFLAGS += $(foreach plugin, $(ROCKSDB_PLUGINS), $($(plugin)_CXXFLAGS))
+
+# Patch up the link flags for JNI from the plugins
+ROCKSDB_PLUGIN_LDFLAGS = $(foreach plugin, $(ROCKSDB_PLUGINS), $($(plugin)_LDFLAGS))
+PLATFORM_LDFLAGS += $(ROCKSDB_PLUGIN_LDFLAGS)
+JAVA_LDFLAGS += $(ROCKSDB_PLUGIN_LDFLAGS)
+JAVA_STATIC_LDFLAGS += $(ROCKSDB_PLUGIN_LDFLAGS)
+
+# Patch up the list of java native sources with files from the plugins
+ROCKSDB_PLUGIN_JNI_NATIVE_SOURCES = $(foreach plugin, $(ROCKSDB_PLUGINS), $(foreach source, $($(plugin)_JNI_NATIVE_SOURCES), plugin/$(plugin)/$(source)))
+ALL_JNI_NATIVE_SOURCES = $(JNI_NATIVE_SOURCES) $(ROCKSDB_PLUGIN_JNI_NATIVE_SOURCES)
+ROCKSDB_PLUGIN_JNI_CXX_INCLUDEFLAGS = $(foreach plugin, $(ROCKSDB_PLUGINS), -I./plugin/$(plugin))
+
+ifneq ($(strip $(ROCKSDB_PLUGIN_PKGCONFIG_REQUIRES)),)
+LDFLAGS := $(LDFLAGS) $(shell pkg-config --libs $(ROCKSDB_PLUGIN_PKGCONFIG_REQUIRES))
+ifneq ($(.SHELLSTATUS),0)
+$(error pkg-config failed)
+endif
+CXXFLAGS := $(CXXFLAGS) $(shell pkg-config --cflags $(ROCKSDB_PLUGIN_PKGCONFIG_REQUIRES))
+ifneq ($(.SHELLSTATUS),0)
+$(error pkg-config failed)
+endif
+endif
+
+CXXFLAGS += $(ARCHFLAG)
+
+ifeq (,$(shell $(CXX) -fsyntax-only -march=armv8-a+crc+crypto -xc /dev/null 2>&1))
+ifneq ($(PLATFORM),OS_MACOSX)
+CXXFLAGS += -march=armv8-a+crc+crypto
+CFLAGS += -march=armv8-a+crc+crypto
+ARMCRC_SOURCE=1
+endif
+endif

 export JAVAC_ARGS
 CLEAN_FILES += make_config.mk rocksdb.pc
@@ -299,12 +318,32 @@ ifeq ($(LIB_MODE),shared)
 EXEC_LDFLAGS += -Wl,-rpath -Wl,'$$ORIGIN'
 endif

+ifeq ($(PLATFORM), OS_MACOSX)
+ifeq ($(ARCHFLAG), -arch arm64)
+ifneq ($(MACHINE), arm64)
+# If we're building on a non-arm64 machine but targeting arm64 Mac, we need to disable
+# linking with jemalloc (as it won't be arm64-compatible) and remove some other options
+# set during platform detection
+DISABLE_JEMALLOC=1
+PLATFORM_CFLAGS := $(filter-out -march=native -DHAVE_SSE42 -DHAVE_AVX2, $(PLATFORM_CFLAGS))
+PLATFORM_CXXFLAGS := $(filter-out -march=native -DHAVE_SSE42 -DHAVE_AVX2, $(PLATFORM_CXXFLAGS))
+endif
+endif
+endif
+
 # ASAN doesn't work well with jemalloc. If we're compiling with ASAN, we should use regular malloc.
 ifdef COMPILE_WITH_ASAN
 	DISABLE_JEMALLOC=1
 	EXEC_LDFLAGS += -fsanitize=address
 	PLATFORM_CCFLAGS += -fsanitize=address
 	PLATFORM_CXXFLAGS += -fsanitize=address
+ifeq ($(LIB_MODE),shared)
+ifdef USE_CLANG
+# Fix false ODR violation; see https://github.com/google/sanitizers/issues/1017
+	EXEC_LDFLAGS += -mllvm -asan-use-private-alias=1
+	PLATFORM_CXXFLAGS += -mllvm -asan-use-private-alias=1
+endif
+endif
 endif

 # TSAN doesn't work well with jemalloc. If we're compiling with TSAN, we should use regular malloc.
@@ -344,6 +383,12 @@ ifdef ROCKSDB_VALGRIND_RUN
 	PLATFORM_CCFLAGS += -DROCKSDB_VALGRIND_RUN
 	PLATFORM_CXXFLAGS += -DROCKSDB_VALGRIND_RUN
 endif
+ifdef ROCKSDB_FULL_VALGRIND_RUN
+	# Some tests are slow when run under valgrind and are only run when
+	# explicitly requested via the ROCKSDB_FULL_VALGRIND_RUN compiler flag.
+	PLATFORM_CCFLAGS += -DROCKSDB_VALGRIND_RUN -DROCKSDB_FULL_VALGRIND_RUN
+	PLATFORM_CXXFLAGS += -DROCKSDB_VALGRIND_RUN -DROCKSDB_FULL_VALGRIND_RUN
+endif

 ifndef DISABLE_JEMALLOC
 	ifdef JEMALLOC
@@ -462,6 +507,11 @@ endif
 CFLAGS += $(C_WARNING_FLAGS) $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CCFLAGS) $(OPT)
 CXXFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers

+# Allow offsetof to work on non-standard layout types. Some compiler could
+# completely reject our usage of offsetof, but we will solve that when it
+# happens.
+CXXFLAGS += -Wno-invalid-offsetof
+
 LDFLAGS += $(PLATFORM_LDFLAGS)

 LIB_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(LIB_SOURCES))
@@ -488,17 +538,20 @@ VALGRIND_ERROR = 2
 VALGRIND_VER := $(join $(VALGRIND_VER),valgrind)

 VALGRIND_OPTS = --error-exitcode=$(VALGRIND_ERROR) --leak-check=full
+# Not yet supported: --show-leak-kinds=definite,possible,reachable --errors-for-leak-kinds=definite,possible,reachable

 TEST_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(TEST_LIB_SOURCES) $(MOCK_LIB_SOURCES)) $(GTEST)
 BENCH_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(BENCH_LIB_SOURCES))
+CACHE_BENCH_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(CACHE_BENCH_LIB_SOURCES))
 TOOL_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(TOOL_LIB_SOURCES))
 ANALYZE_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(ANALYZER_LIB_SOURCES))
 STRESS_OBJECTS =  $(patsubst %.cc, $(OBJ_DIR)/%.o, $(STRESS_LIB_SOURCES))

 # Exclude build_version.cc -- a generated source file -- from all sources.  Not needed for dependencies
 ALL_SOURCES  = $(filter-out util/build_version.cc, $(LIB_SOURCES)) $(TEST_LIB_SOURCES) $(MOCK_LIB_SOURCES) $(GTEST_DIR)/gtest/gtest-all.cc
-ALL_SOURCES += $(TOOL_LIB_SOURCES) $(BENCH_LIB_SOURCES) $(ANALYZER_LIB_SOURCES) $(STRESS_LIB_SOURCES)
+ALL_SOURCES += $(TOOL_LIB_SOURCES) $(BENCH_LIB_SOURCES) $(CACHE_BENCH_LIB_SOURCES) $(ANALYZER_LIB_SOURCES) $(STRESS_LIB_SOURCES)
 ALL_SOURCES += $(TEST_MAIN_SOURCES) $(TOOL_MAIN_SOURCES) $(BENCH_MAIN_SOURCES)
+ALL_SOURCES += $(ROCKSDB_PLUGIN_SOURCES)

 TESTS = $(patsubst %.cc, %, $(notdir $(TEST_MAIN_SOURCES)))
 TESTS += $(patsubst %.c, %, $(notdir $(TEST_MAIN_SOURCES_C)))
@@ -508,29 +561,54 @@ ifeq ($(USE_FOLLY_DISTRIBUTED_MUTEX),1)
 	ALL_SOURCES += third-party/folly/folly/synchronization/test/DistributedMutexTest.cc
 endif

+# `make check-headers` to very that each header file includes its own
+# dependencies
+ifneq ($(filter check-headers, $(MAKECMDGOALS)),)
+# TODO: add/support JNI headers
+	DEV_HEADER_DIRS := $(sort include/ $(dir $(ALL_SOURCES)))
+# Some headers like in port/ are platform-specific
+	DEV_HEADERS := $(shell $(FIND) $(DEV_HEADER_DIRS) -type f -name '*.h' | egrep -v 'port/|plugin/|lua/|range_tree/')
+else
+	DEV_HEADERS :=
+endif
+HEADER_OK_FILES = $(patsubst %.h, %.h.ok, $(DEV_HEADERS))
+
+AM_V_CCH = $(am__v_CCH_$(V))
+am__v_CCH_ = $(am__v_CCH_$(AM_DEFAULT_VERBOSITY))
+am__v_CCH_0 = @echo "  CC.h    " $<;
+am__v_CCH_1 =
+
+%.h.ok: %.h # .h.ok not actually created, so re-checked on each invocation
+# -DROCKSDB_NAMESPACE=42 ensures the namespace header is included
+	$(AM_V_CCH) echo '#include "$<"' | $(CXX) $(CXXFLAGS) -DROCKSDB_NAMESPACE=42 -x c++ -c - -o /dev/null
+
+check-headers: $(HEADER_OK_FILES)
+
 # options_settable_test doesn't pass with UBSAN as we use hack in the test
 ifdef COMPILE_WITH_UBSAN
-        TESTS := $(shell echo $(TESTS) | sed 's/\boptions_settable_test\b//g')
+TESTS := $(shell echo $(TESTS) | sed 's/\boptions_settable_test\b//g')
 endif
 ifdef ASSERT_STATUS_CHECKED
-	# TODO: finish fixing all tests to pass this check
-	TESTS_FAILING_ASC = \
-		db_test \
-		db_test2 \
-		range_locking_test \
-		testutil_test \
+# TODO: finish fixing all tests to pass this check
+TESTS_FAILING_ASC = \
+	c_test \
+	env_test \
+	range_locking_test \
+	testutil_test \

-	# Since we have very few ASC exclusions left, excluding them from
-	# the build is the most convenient way to exclude them from testing
-	TESTS := $(filter-out $(TESTS_FAILING_ASC),$(TESTS))
+# Since we have very few ASC exclusions left, excluding them from
+# the build is the most convenient way to exclude them from testing
+TESTS := $(filter-out $(TESTS_FAILING_ASC),$(TESTS))
 endif

 ROCKSDBTESTS_SUBSET ?= $(TESTS)

+# c_test - doesn't use gtest
 # env_test - suspicious use of test::TmpDir
 # deletefile_test - serial because it generates giant temporary files in
 #   its various tests. Parallel can fill up your /dev/shm
 NON_PARALLEL_TEST = \
+	c_test \
 	env_test \
 	deletefile_test \

@@ -592,6 +670,8 @@ TEST_LIBS = \
 # TODO: add back forward_iterator_bench, after making it build in all environemnts.
 BENCHMARKS = $(patsubst %.cc, %, $(notdir $(BENCH_MAIN_SOURCES)))

+MICROBENCHS = $(patsubst %.cc, %, $(notdir $(MICROBENCH_SOURCES)))
+
 # if user didn't config LIBNAME, set the default
 ifeq ($(LIBNAME),)
  LIBNAME=librocksdb
@@ -705,11 +785,13 @@ endif  # PLATFORM_SHARED_EXT
 .PHONY: blackbox_crash_test check clean coverage crash_test ldb_tests package \
 	release tags tags0 valgrind_check whitebox_crash_test format static_lib shared_lib all \
 	dbg rocksdbjavastatic rocksdbjava gen-pc install install-static install-shared uninstall \
-	analyze tools tools_lib \
+	analyze tools tools_lib check-headers \
 	blackbox_crash_test_with_atomic_flush whitebox_crash_test_with_atomic_flush  \
 	blackbox_crash_test_with_txn whitebox_crash_test_with_txn \
 	blackbox_crash_test_with_best_efforts_recovery \
-	blackbox_crash_test_with_ts whitebox_crash_test_with_ts
+	blackbox_crash_test_with_ts whitebox_crash_test_with_ts \
+	blackbox_crash_test_with_multiops_wc_txn \
+	blackbox_crash_test_with_multiops_wp_txn


 all: $(LIBRARY) $(BENCHMARKS) tools tools_lib test_libs $(TESTS)
@@ -730,6 +812,11 @@ test_libs: $(TEST_LIBS)

 benchmarks: $(BENCHMARKS)

+microbench: $(MICROBENCHS)
+
+run_microbench: $(MICROBENCHS)
+	for t in $(MICROBENCHS); do echo "===== Running benchmark $$t (`date`)"; ./$$t || exit 1; done;
+
 dbg: $(LIBRARY) $(BENCHMARKS) tools $(TESTS)

 # creates library and programs
@@ -739,8 +826,8 @@ release: clean
 coverage: clean
 	COVERAGEFLAGS="-fprofile-arcs -ftest-coverage" LDFLAGS+="-lgcov" $(MAKE) J=1 all check
 	cd coverage && ./coverage_test.sh
-        # Delete intermediate files
-	$(FIND) . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm -f {} \;
+	# Delete intermediate files
+	$(FIND) . -type f \( -name "*.gcda" -o -name "*.gcno" \) -exec rm -f {} \;

 ifneq (,$(filter check parallel_check,$(MAKECMDGOALS)),)
 # Use /dev/shm if it has the sticky bit set (otherwise, /tmp),
@@ -783,17 +870,14 @@ endif

 parallel_tests = $(patsubst %,parallel_%,$(PARALLEL_TEST))
 .PHONY: gen_parallel_tests $(parallel_tests)
-$(parallel_tests): $(PARALLEL_TEST)
+$(parallel_tests):
 	$(AM_V_at)TEST_BINARY=$(patsubst parallel_%,%,$@); \
  TEST_NAMES=` \
-    ./$$TEST_BINARY --gtest_list_tests \
-    | perl -n \
-      -e 's/ *\#.*//;' \
-      -e '/^(\s*)(\S+)/; !$$1 and do {$$p=$$2; break};'	\
-      -e 'print qq! $$p$$2!'`; \
+    (./$$TEST_BINARY --gtest_list_tests || echo "  $${TEST_BINARY}__list_tests_failure") \
+    | awk '/^[^ ]/ { prefix = $$1 } /^[ ]/ { print prefix $$1 }'`; \
+	echo "  Generating parallel test scripts for $$TEST_BINARY"; \
 	for TEST_NAME in $$TEST_NAMES; do \
 		TEST_SCRIPT=t/run-$$TEST_BINARY-$${TEST_NAME//\//-}; \
-		echo "  GEN     " $$TEST_SCRIPT; \
    printf '%s\n' \
      '#!/bin/sh' \
      "d=\$(TMPD)$$TEST_SCRIPT" \
@@ -825,7 +909,7 @@ gen_parallel_tests:
 # 107.816 PASS t/DBTest.EncodeDecompressedBlockSizeTest
 #
 slow_test_regexp = \
-	^.*SnapshotConcurrentAccessTest.*$$|^.*SeqAdvanceConcurrentTest.*$$|^t/run-table_test-HarnessTest.Randomized$$|^t/run-db_test-.*(?:FileCreationRandomFailure|EncodeDecompressedBlockSizeTest)$$|^.*RecoverFromCorruptedWALWithoutFlush$$
+	^.*MySQLStyleTransactionTest.*$$|^.*SnapshotConcurrentAccessTest.*$$|^.*SeqAdvanceConcurrentTest.*$$|^t/run-table_test-HarnessTest.Randomized$$|^t/run-db_test-.*(?:FileCreationRandomFailure|EncodeDecompressedBlockSizeTest)$$|^.*RecoverFromCorruptedWALWithoutFlush$$
 prioritize_long_running_tests =						\
  perl -pe 's,($(slow_test_regexp)),100 $$1,'				\
    | sort -k1,1gr							\
@@ -840,12 +924,18 @@ J ?= 100%

 # Use this regexp to select the subset of tests whose names match.
 tests-regexp = .
-EXCLUDE_TESTS_REGEX ?= "^$"
+EXCLUDE_TESTS_REGEX ?= "^$$"

 ifeq ($(PRINT_PARALLEL_OUTPUTS), 1)
-	parallel_com = '{}'
+	parallel_redir =
+else ifeq ($(QUIET_PARALLEL_TESTS), 1)
+	parallel_redir = >& t/$(test_log_prefix)log-{/}
 else
-	parallel_com = '{} >& t/log-{/}'
+# Default: print failure output only, as it happens
+# Note: gnu_parallel --eta is now always used, but has been modified to provide
+# only infrequent updates when not connected to a terminal. (CircleCI will
+# kill a job if no output for 10min.)
+	parallel_redir = >& t/$(test_log_prefix)log-{/} || bash -c "cat t/$(test_log_prefix)log-{/}; exit $$?"
 endif

 .PHONY: check_0
@@ -854,7 +944,6 @@ check_0:
 	printf '%s\n' ''						\
 	  'To monitor subtest <duration,pass/fail,name>,'		\
 	  '  run "make watch-log" in a separate window' '';		\
-	test -t 1 && eta=--eta || eta=; \
 	{ \
 		printf './%s\n' $(filter-out $(PARALLEL_TEST),$(TESTS)); \
 		find t -name 'run-*' -print; \
@@ -862,7 +951,7 @@ check_0:
 	  | $(prioritize_long_running_tests)				\
 	  | grep -E '$(tests-regexp)'					\
 	  | grep -E -v '$(EXCLUDE_TESTS_REGEX)'					\
-	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG $$eta --gnu  $(parallel_com) ; \
+	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG --eta --gnu '{} $(parallel_redir)' ; \
 	parallel_retcode=$$? ; \
 	awk '{ if ($$7 != 0 || $$8 != 0) { if ($$7 == "Exitval") { h = $$0; } else { if (!f) print h; print; f = 1 } } } END { if(f) exit 1; }' < LOG ; \
 	awk_retcode=$$?; \
@@ -871,12 +960,12 @@ check_0:
 valgrind-exclude-regexp = InlineSkipTest.ConcurrentInsert|TransactionStressTest.DeadlockStress|DBCompactionTest.SuggestCompactRangeNoTwoLevel0Compactions|BackupableDBTest.RateLimiting|DBTest.CloseSpeedup|DBTest.ThreadStatusFlush|DBTest.RateLimitingTest|DBTest.EncodeDecompressedBlockSizeTest|FaultInjectionTest.UninstalledCompaction|HarnessTest.Randomized|ExternalSSTFileTest.CompactDuringAddFileRandom|ExternalSSTFileTest.IngestFileWithGlobalSeqnoRandomized|MySQLStyleTransactionTest.TransactionStressTest

 .PHONY: valgrind_check_0
+valgrind_check_0: test_log_prefix := valgrind_
 valgrind_check_0:
 	$(AM_V_GEN)export TEST_TMPDIR=$(TMPD);				\
 	printf '%s\n' ''						\
 	  'To monitor subtest <duration,pass/fail,name>,'		\
 	  '  run "make watch-log" in a separate window' '';		\
-	test -t 1 && eta=--eta || eta=;					\
 	{								\
 	  printf './%s\n' $(filter-out $(PARALLEL_TEST) %skiplist_test options_settable_test, $(TESTS));		\
 	  find t -name 'run-*' -print; \
@@ -884,9 +973,9 @@ valgrind_check_0:
 	  | $(prioritize_long_running_tests)				\
 	  | grep -E '$(tests-regexp)'					\
 	  | grep -E -v '$(valgrind-exclude-regexp)'					\
-	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG $$eta --gnu \
-	  '(if [[ "{}" == "./"* ]] ; then $(DRIVER) {}; else {}; fi) ' \
-	  '>& t/valgrind_log-{/}'
+	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG --eta --gnu \
+	  '(if [[ "{}" == "./"* ]] ; then $(DRIVER) {}; else {}; fi) \
+	  $(parallel_redir)' \

 CLEAN_FILES += t LOG $(TMPD)

@@ -929,6 +1018,7 @@ endif
 ifndef SKIP_FORMAT_BUCK_CHECKS
 	$(MAKE) check-format
 	$(MAKE) check-buck-targets
+	$(MAKE) check-sources
 endif

 # TODO add ldb_tests
@@ -939,80 +1029,34 @@ check_some: $(ROCKSDBTESTS_SUBSET)
 ldb_tests: ldb
 	$(PYTHON) tools/ldb_test.py

-crash_test: whitebox_crash_test blackbox_crash_test
-
-crash_test_with_atomic_flush: whitebox_crash_test_with_atomic_flush blackbox_crash_test_with_atomic_flush
-
-crash_test_with_txn: whitebox_crash_test_with_txn blackbox_crash_test_with_txn
-
-crash_test_with_best_efforts_recovery: blackbox_crash_test_with_best_efforts_recovery
-
-crash_test_with_ts: whitebox_crash_test_with_ts blackbox_crash_test_with_ts
-
-blackbox_crash_test: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --simple blackbox $(CRASH_TEST_EXT_ARGS)
-	$(PYTHON) -u tools/db_crashtest.py blackbox $(CRASH_TEST_EXT_ARGS)
-
-blackbox_crash_test_with_atomic_flush: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --cf_consistency blackbox $(CRASH_TEST_EXT_ARGS)
-
-blackbox_crash_test_with_txn: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --txn blackbox $(CRASH_TEST_EXT_ARGS)
-
-blackbox_crash_test_with_best_efforts_recovery: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --test_best_efforts_recovery blackbox $(CRASH_TEST_EXT_ARGS)
-
-blackbox_crash_test_with_ts: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --enable_ts blackbox $(CRASH_TEST_EXT_ARGS)
-
-ifeq ($(CRASH_TEST_KILL_ODD),)
-  CRASH_TEST_KILL_ODD=888887
-endif
-
-whitebox_crash_test: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --simple whitebox --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
-	$(PYTHON) -u tools/db_crashtest.py whitebox  --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
-
-whitebox_crash_test_with_atomic_flush: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --cf_consistency whitebox  --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
-
-whitebox_crash_test_with_txn: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --txn whitebox --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
-
-whitebox_crash_test_with_ts: db_stress
-	$(PYTHON) -u tools/db_crashtest.py --enable_ts whitebox --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+include crash_test.mk

 asan_check: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) check -j32
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) check -j32
 	$(MAKE) clean

 asan_crash_test: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) crash_test
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) crash_test
 	$(MAKE) clean

 whitebox_asan_crash_test: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) whitebox_crash_test
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) whitebox_crash_test
 	$(MAKE) clean

 blackbox_asan_crash_test: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) blackbox_crash_test
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) blackbox_crash_test
 	$(MAKE) clean

 asan_crash_test_with_atomic_flush: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) crash_test_with_atomic_flush
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) crash_test_with_atomic_flush
 	$(MAKE) clean

 asan_crash_test_with_txn: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) crash_test_with_txn
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) crash_test_with_txn
 	$(MAKE) clean

 asan_crash_test_with_best_efforts_recovery: clean
-	COMPILE_WITH_ASAN=1 $(MAKE) crash_test_with_best_efforts_recovery
+	ASAN_OPTIONS=detect_stack_use_after_return=1 COMPILE_WITH_ASAN=1 $(MAKE) crash_test_with_best_efforts_recovery
 	$(MAKE) clean

 ubsan_check: clean
@@ -1043,6 +1087,12 @@ ubsan_crash_test_with_best_efforts_recovery: clean
 	COMPILE_WITH_UBSAN=1 $(MAKE) crash_test_with_best_efforts_recovery
 	$(MAKE) clean

+full_valgrind_test:
+	ROCKSDB_FULL_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check
+
+full_valgrind_test_some:
+	ROCKSDB_FULL_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check_some
+
 valgrind_test:
 	ROCKSDB_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check

@@ -1129,7 +1179,7 @@ analyze_incremental:
 	$(CLANG_SCAN_BUILD) --use-analyzer=$(CLANG_ANALYZER) \
 		--use-c++=$(CXX) --use-cc=$(CC) --status-bugs \
 		-o $(CURDIR)/scan_build_report \
-		$(MAKE) dbg
+		$(MAKE) SKIP_LINK=1 dbg

 CLEAN_FILES += unity.cc
 unity.cc: Makefile util/build_version.cc.in
@@ -1161,12 +1211,12 @@ clean-not-downloaded: clean-ext-libraries-bin clean-rocks clean-not-downloaded-r
 clean-rocks:
 	echo shared=$(ALL_SHARED_LIBS)
 	echo static=$(ALL_STATIC_LIBS)
-	rm -f $(BENCHMARKS) $(TOOLS) $(TESTS) $(PARALLEL_TEST) $(ALL_STATIC_LIBS) $(ALL_SHARED_LIBS)
+	rm -f $(BENCHMARKS) $(TOOLS) $(TESTS) $(PARALLEL_TEST) $(ALL_STATIC_LIBS) $(ALL_SHARED_LIBS) $(MICROBENCHS)
 	rm -rf $(CLEAN_FILES) ios-x86 ios-arm scan_build_report
 	$(FIND) . -name "*.[oda]" -exec rm -f {} \;
-	$(FIND) . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm -f {} \;
+	$(FIND) . -type f \( -name "*.gcda" -o -name "*.gcno" \) -exec rm -f {} \;

-clean-rocksjava:
+clean-rocksjava: clean-rocks
 	rm -rf jl jls
 	cd java && $(MAKE) clean

@@ -1200,6 +1250,9 @@ check-format:
 check-buck-targets:
 	buckifier/check_buck_targets.sh

+check-sources:
+	build_tools/check-sources.sh
+
 package:
 	bash build_tools/make_package.sh $(SHARED_MAJOR).$(SHARED_MINOR)

@@ -1252,7 +1305,7 @@ folly_synchronization_distributed_mutex_test: $(OBJ_DIR)/third-party/folly/folly
 	$(AM_LINK)
 endif

-cache_bench: $(OBJ_DIR)/cache/cache_bench.o $(LIBRARY)
+cache_bench: $(OBJ_DIR)/cache/cache_bench.o $(CACHE_BENCH_OBJECTS) $(LIBRARY)
 	$(AM_LINK)

 persistent_cache_bench: $(OBJ_DIR)/utilities/persistent_cache/persistent_cache_bench.o $(LIBRARY)
@@ -1279,7 +1332,7 @@ db_repl_stress: $(OBJ_DIR)/tools/db_repl_stress.o $(LIBRARY)
 arena_test: $(OBJ_DIR)/memory/arena_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

-memkind_kmem_allocator_test: memory/memkind_kmem_allocator_test.o $(TEST_LIBRARY) $(LIBRARY)
+memory_allocator_test: memory/memory_allocator_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

 autovector_test: $(OBJ_DIR)/util/autovector_test.o $(TEST_LIBRARY) $(LIBRARY)
@@ -1432,6 +1485,9 @@ db_options_test: $(OBJ_DIR)/db/db_options_test.o $(TEST_LIBRARY) $(LIBRARY)
 db_range_del_test: $(OBJ_DIR)/db/db_range_del_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

+db_rate_limiter_test: $(OBJ_DIR)/db/db_rate_limiter_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 db_sst_test: $(OBJ_DIR)/db/db_sst_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1495,7 +1551,7 @@ perf_context_test: $(OBJ_DIR)/db/perf_context_test.o $(TEST_LIBRARY) $(LIBRARY)
 prefix_test: $(OBJ_DIR)/db/prefix_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

-backupable_db_test: $(OBJ_DIR)/utilities/backupable/backupable_db_test.o $(TEST_LIBRARY) $(LIBRARY)
+backup_engine_test: $(OBJ_DIR)/utilities/backup/backup_engine_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

 checkpoint_test: $(OBJ_DIR)/utilities/checkpoint/checkpoint_test.o $(TEST_LIBRARY) $(LIBRARY)
@@ -1513,11 +1569,6 @@ env_mirror_test: $(OBJ_DIR)/utilities/env_mirror_test.o $(TEST_LIBRARY) $(LIBRAR
 env_timed_test: $(OBJ_DIR)/utilities/env_timed_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

-ifdef ROCKSDB_USE_LIBRADOS
-env_librados_test: $(OBJ_DIR)/utilities/env_librados_test.o $(TEST_LIBRARY) $(LIBRARY)
-	$(AM_LINK)
-endif
-
 object_registry_test: $(OBJ_DIR)/utilities/object_registry_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1539,6 +1590,9 @@ compaction_job_test: $(OBJ_DIR)/db/compaction/compaction_job_test.o $(TEST_LIBRA
 compaction_job_stats_test: $(OBJ_DIR)/db/compaction/compaction_job_stats_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

+compaction_service_test: $(OBJ_DIR)/db/compaction/compaction_service_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 compact_on_deletion_collector_test: $(OBJ_DIR)/utilities/table_properties_collectors/compact_on_deletion_collector_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1752,6 +1806,9 @@ point_lock_manager_test: utilities/transactions/lock/point/point_lock_manager_te
 transaction_test: $(OBJ_DIR)/utilities/transactions/transaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

+write_committed_transaction_ts_test: $(OBJ_DIR)/utilities/transactions/write_committed_transaction_ts_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 write_prepared_transaction_test: $(OBJ_DIR)/utilities/transactions/write_prepared_transaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1785,6 +1842,9 @@ statistics_test: $(OBJ_DIR)/monitoring/statistics_test.o $(TEST_LIBRARY) $(LIBRA
 stats_history_test: $(OBJ_DIR)/monitoring/stats_history_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

+lru_secondary_cache_test: $(OBJ_DIR)/cache/lru_secondary_cache_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 lru_cache_test: $(OBJ_DIR)/cache/lru_cache_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1821,6 +1881,9 @@ block_cache_trace_analyzer_test: $(OBJ_DIR)/tools/block_cache_analyzer/block_cac
 defer_test: $(OBJ_DIR)/util/defer_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

+blob_counting_iterator_test: $(OBJ_DIR)/db/blob/blob_counting_iterator_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 blob_file_addition_test: $(OBJ_DIR)/db/blob/blob_file_addition_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1836,6 +1899,9 @@ blob_file_garbage_test: $(OBJ_DIR)/db/blob/blob_file_garbage_test.o $(TEST_LIBRA
 blob_file_reader_test: $(OBJ_DIR)/db/blob/blob_file_reader_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

+blob_garbage_meter_test: $(OBJ_DIR)/db/blob/blob_garbage_meter_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 timer_test: $(OBJ_DIR)/util/timer_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

@@ -1862,6 +1928,18 @@ db_blob_corruption_test: $(OBJ_DIR)/db/blob/db_blob_corruption_test.o $(TEST_LIB

 db_write_buffer_manager_test: $(OBJ_DIR)/db/db_write_buffer_manager_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
+
+clipping_iterator_test: $(OBJ_DIR)/db/compaction/clipping_iterator_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
+ribbon_bench: $(OBJ_DIR)/microbench/ribbon_bench.o $(LIBRARY)
+	$(AM_LINK)
+
+db_basic_bench: $(OBJ_DIR)/microbench/db_basic_bench.o $(LIBRARY)
+	$(AM_LINK)
+
+cache_reservation_manager_test: $(OBJ_DIR)/cache/cache_reservation_manager_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
 #-------------------------------------------------
 # make install related stuff
 PREFIX ?= /usr/local
@@ -1920,6 +1998,7 @@ gen-pc:
 	-echo 'Libs: -L$${libdir} $(EXEC_LDFLAGS) -lrocksdb' >> rocksdb.pc
 	-echo 'Libs.private: $(PLATFORM_LDFLAGS)' >> rocksdb.pc
 	-echo 'Cflags: -I$${includedir} $(PLATFORM_CXXFLAGS)' >> rocksdb.pc
+	-echo 'Requires: $(subst ",,$(ROCKSDB_PLUGIN_PKGCONFIG_REQUIRES))' >> rocksdb.pc

 #-------------------------------------------------

@@ -1927,12 +2006,11 @@ gen-pc:
 # ---------------------------------------------------------------------------
 # Jni stuff
 # ---------------------------------------------------------------------------
-
 JAVA_INCLUDE = -I$(JAVA_HOME)/include/ -I$(JAVA_HOME)/include/linux
 ifeq ($(PLATFORM), OS_SOLARIS)
 	ARCH := $(shell isainfo -b)
 else ifeq ($(PLATFORM), OS_OPENBSD)
-	ifneq (,$(filter amd64 ppc64 ppc64le arm64 aarch64 sparc64, $(MACHINE)))
+	ifneq (,$(filter amd64 ppc64 ppc64le s390x arm64 aarch64 sparc64, $(MACHINE)))
 		ARCH := 64
 	else
 		ARCH := 32
@@ -1952,11 +2030,13 @@ ifneq ($(origin JNI_LIBC), undefined)
  JNI_LIBC_POSTFIX = -$(JNI_LIBC)
 endif

-ifneq (,$(filter ppc% arm64 aarch64 sparc64, $(MACHINE)))
+ifeq (,$(ROCKSDBJNILIB))
+ifneq (,$(filter ppc% s390x arm64 aarch64 sparc64, $(MACHINE)))
 	ROCKSDBJNILIB = librocksdbjni-linux-$(MACHINE)$(JNI_LIBC_POSTFIX).so
 else
 	ROCKSDBJNILIB = librocksdbjni-linux$(ARCH)$(JNI_LIBC_POSTFIX).so
 endif
+endif
 ROCKSDB_JAVA_VERSION ?= $(ROCKSDB_MAJOR).$(ROCKSDB_MINOR).$(ROCKSDB_PATCH)
 ROCKSDB_JAR = rocksdbjni-$(ROCKSDB_JAVA_VERSION)-linux$(ARCH)$(JNI_LIBC_POSTFIX).jar
 ROCKSDB_JAR_ALL = rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar
@@ -1964,12 +2044,12 @@ ROCKSDB_JAVADOCS_JAR = rocksdbjni-$(ROCKSDB_JAVA_VERSION)-javadoc.jar
 ROCKSDB_SOURCES_JAR = rocksdbjni-$(ROCKSDB_JAVA_VERSION)-sources.jar
 SHA256_CMD = sha256sum

-ZLIB_VER ?= 1.2.11
-ZLIB_SHA256 ?= c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1
+ZLIB_VER ?= 1.2.12
+ZLIB_SHA256 ?= 91844808532e5ce316b3c010929493c0244f3d37593afd6de04f71821d5136d9
 ZLIB_DOWNLOAD_BASE ?= http://zlib.net
 BZIP2_VER ?= 1.0.8
 BZIP2_SHA256 ?= ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269
-BZIP2_DOWNLOAD_BASE ?= https://sourceware.org/pub/bzip2
+BZIP2_DOWNLOAD_BASE ?= http://sourceware.org/pub/bzip2
 SNAPPY_VER ?= 1.1.8
 SNAPPY_SHA256 ?= 16b677f07832a612b0836178db7f374e414f94657c138e6993cbfc5dcc58651f
 SNAPPY_DOWNLOAD_BASE ?= https://github.com/google/snappy/archive
@@ -1982,7 +2062,15 @@ ZSTD_DOWNLOAD_BASE ?= https://github.com/facebook/zstd/archive
 CURL_SSL_OPTS ?= --tlsv1

 ifeq ($(PLATFORM), OS_MACOSX)
+ifeq (,$(findstring librocksdbjni-osx,$(ROCKSDBJNILIB)))
+ifeq ($(MACHINE),arm64)
+	ROCKSDBJNILIB = librocksdbjni-osx-arm64.jnilib
+else ifeq ($(MACHINE),x86_64)
+	ROCKSDBJNILIB = librocksdbjni-osx-x86_64.jnilib
+else
 	ROCKSDBJNILIB = librocksdbjni-osx.jnilib
+endif
+endif
 	ROCKSDB_JAR = rocksdbjni-$(ROCKSDB_JAVA_VERSION)-osx.jar
 	SHA256_CMD = openssl sha256 -r
 ifneq ("$(wildcard $(JAVA_HOME)/include/darwin)","")
@@ -1991,6 +2079,7 @@ else
 	JAVA_INCLUDE = -I/System/Library/Frameworks/JavaVM.framework/Headers/
 endif
 endif
+
 ifeq ($(PLATFORM), OS_FREEBSD)
 	JAVA_INCLUDE = -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/freebsd
 	ROCKSDBJNILIB = librocksdbjni-freebsd$(ARCH).so
@@ -2025,7 +2114,11 @@ zlib-$(ZLIB_VER).tar.gz:
 libz.a: zlib-$(ZLIB_VER).tar.gz
 	-rm -rf zlib-$(ZLIB_VER)
 	tar xvzf zlib-$(ZLIB_VER).tar.gz
-	cd zlib-$(ZLIB_VER) && CFLAGS='-fPIC ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' ./configure --static && $(MAKE)
+	if [ -n"$(ARCHFLAG)" ]; then \
+		cd zlib-$(ZLIB_VER) && CFLAGS='-fPIC ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' ./configure --static --archs="$(ARCHFLAG)" && $(MAKE);  \
+	else \
+		cd zlib-$(ZLIB_VER) && CFLAGS='-fPIC ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' ./configure --static && $(MAKE);  \
+	fi
 	cp zlib-$(ZLIB_VER)/libz.a .

 bzip2-$(BZIP2_VER).tar.gz:
@@ -2039,7 +2132,7 @@ bzip2-$(BZIP2_VER).tar.gz:
 libbz2.a: bzip2-$(BZIP2_VER).tar.gz
 	-rm -rf bzip2-$(BZIP2_VER)
 	tar xvzf bzip2-$(BZIP2_VER).tar.gz
-	cd bzip2-$(BZIP2_VER) && $(MAKE) CFLAGS='-fPIC -O2 -g -D_FILE_OFFSET_BITS=64 ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' AR='ar ${EXTRA_ARFLAGS}'
+	cd bzip2-$(BZIP2_VER) && $(MAKE) CFLAGS='-fPIC -O2 -g -D_FILE_OFFSET_BITS=64 $(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' AR='ar ${EXTRA_ARFLAGS}' libbz2.a
 	cp bzip2-$(BZIP2_VER)/libbz2.a .

 snappy-$(SNAPPY_VER).tar.gz:
@@ -2054,7 +2147,7 @@ libsnappy.a: snappy-$(SNAPPY_VER).tar.gz
 	-rm -rf snappy-$(SNAPPY_VER)
 	tar xvzf snappy-$(SNAPPY_VER).tar.gz
 	mkdir snappy-$(SNAPPY_VER)/build
-	cd snappy-$(SNAPPY_VER)/build && CFLAGS='${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' CXXFLAGS='${JAVA_STATIC_DEPS_CXXFLAGS} ${EXTRA_CXXFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON ${PLATFORM_CMAKE_FLAGS} .. && $(MAKE) ${SNAPPY_MAKE_TARGET}
+	cd snappy-$(SNAPPY_VER)/build && CFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' CXXFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CXXFLAGS} ${EXTRA_CXXFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON ${PLATFORM_CMAKE_FLAGS} .. && $(MAKE) ${SNAPPY_MAKE_TARGET}
 	cp snappy-$(SNAPPY_VER)/build/libsnappy.a .

 lz4-$(LZ4_VER).tar.gz:
@@ -2068,7 +2161,7 @@ lz4-$(LZ4_VER).tar.gz:
 liblz4.a: lz4-$(LZ4_VER).tar.gz
 	-rm -rf lz4-$(LZ4_VER)
 	tar xvzf lz4-$(LZ4_VER).tar.gz
-	cd lz4-$(LZ4_VER)/lib && $(MAKE) CFLAGS='-fPIC -O2 ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' all
+	cd lz4-$(LZ4_VER)/lib && $(MAKE) CFLAGS='-fPIC -O2 $(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' all
 	cp lz4-$(LZ4_VER)/lib/liblz4.a .

 zstd-$(ZSTD_VER).tar.gz:
@@ -2082,7 +2175,7 @@ zstd-$(ZSTD_VER).tar.gz:
 libzstd.a: zstd-$(ZSTD_VER).tar.gz
 	-rm -rf zstd-$(ZSTD_VER)
 	tar xvzf zstd-$(ZSTD_VER).tar.gz
-	cd zstd-$(ZSTD_VER)/lib && DESTDIR=. PREFIX= $(MAKE) CFLAGS='-fPIC -O2 ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' libzstd.a
+	cd zstd-$(ZSTD_VER)/lib && DESTDIR=. PREFIX= $(MAKE) CFLAGS='-fPIC -O2 $(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' libzstd.a
 	cp zstd-$(ZSTD_VER)/lib/libzstd.a .

 # A version of each $(LIB_OBJECTS) compiled with -fPIC and a fixed set of static compression libraries
@@ -2104,41 +2197,82 @@ endif
 	$(MAKE) rocksdbjavastatic_deps
 	$(MAKE) rocksdbjavastatic_libobjects
 	$(MAKE) rocksdbjavastatic_javalib
+	$(MAKE) rocksdbjava_jar

+rocksdbjavastaticosx: rocksdbjavastaticosx_archs
+	cd java; $(JAR_CMD)  -cf target/$(ROCKSDB_JAR) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) librocksdbjni-osx-x86_64.jnilib librocksdbjni-osx-arm64.jnilib
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
+	openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1
+
+rocksdbjavastaticosx_ub: rocksdbjavastaticosx_archs
+	cd java/target; lipo -create -output librocksdbjni-osx.jnilib librocksdbjni-osx-x86_64.jnilib librocksdbjni-osx-arm64.jnilib
+	cd java; $(JAR_CMD)  -cf target/$(ROCKSDB_JAR) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) librocksdbjni-osx.jnilib
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
+	openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1
+
+rocksdbjavastaticosx_archs:
+	$(MAKE) rocksdbjavastaticosx_arch_x86_64
+	$(MAKE) rocksdbjavastaticosx_arch_arm64
+
+rocksdbjavastaticosx_arch_%:
+ifeq ($(JAVA_HOME),)
+	$(error JAVA_HOME is not set)
+endif
+	$(MAKE) clean-ext-libraries-bin
+	$(MAKE) clean-rocks
+	ARCHFLAG="-arch $*" $(MAKE) rocksdbjavastatic_deps
+	ARCHFLAG="-arch $*" $(MAKE) rocksdbjavastatic_libobjects
+	ARCHFLAG="-arch $*" ROCKSDBJNILIB="librocksdbjni-osx-$*.jnilib" $(MAKE) rocksdbjavastatic_javalib
+
+ifeq ($(JAR_CMD),)
+ifneq ($(JAVA_HOME),)
+JAR_CMD := $(JAVA_HOME)/bin/jar
+else
+JAR_CMD := jar
+endif
+endif
 rocksdbjavastatic_javalib:
 	cd java; SHA256_CMD='$(SHA256_CMD)' $(MAKE) javalib
 	rm -f java/target/$(ROCKSDBJNILIB)
 	$(CXX) $(CXXFLAGS) -I./java/. $(JAVA_INCLUDE) -shared -fPIC \
-	  -o ./java/target/$(ROCKSDBJNILIB) $(JNI_NATIVE_SOURCES) \
+	  -o ./java/target/$(ROCKSDBJNILIB) $(ALL_JNI_NATIVE_SOURCES) \
 	  $(LIB_OBJECTS) $(COVERAGEFLAGS) \
 	  $(JAVA_COMPRESSIONS) $(JAVA_STATIC_LDFLAGS)
 	cd java/target;if [ "$(DEBUG_LEVEL)" == "0" ]; then \
 		strip $(STRIPFLAGS) $(ROCKSDBJNILIB); \
 	fi
-	cd java;jar -cf target/$(ROCKSDB_JAR) HISTORY*.md
-	cd java/target;jar -uf $(ROCKSDB_JAR) $(ROCKSDBJNILIB)
-	cd java/target/classes;jar -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
-	cd java/target/apidocs;jar -cf ../$(ROCKSDB_JAVADOCS_JAR) *
-	cd java/src/main/java;jar -cf ../../../target/$(ROCKSDB_SOURCES_JAR) org
+
+rocksdbjava_jar:
+	cd java; $(JAR_CMD)  -cf target/$(ROCKSDB_JAR) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) $(ROCKSDBJNILIB)
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
 	openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1
+
+rocksdbjava_javadocs_jar:
+	cd java/target/apidocs; $(JAR_CMD) -cf ../$(ROCKSDB_JAVADOCS_JAR) *
 	openssl sha1 java/target/$(ROCKSDB_JAVADOCS_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAVADOCS_JAR).sha1
+
+rocksdbjava_sources_jar:
+	cd java/src/main/java; $(JAR_CMD) -cf ../../../target/$(ROCKSDB_SOURCES_JAR) org
 	openssl sha1 java/target/$(ROCKSDB_SOURCES_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_SOURCES_JAR).sha1

 rocksdbjavastatic_deps: $(JAVA_COMPRESSIONS)

 rocksdbjavastatic_libobjects: $(LIB_OBJECTS)

-rocksdbjavastaticrelease: rocksdbjavastatic
+rocksdbjavastaticrelease: rocksdbjavastaticosx rocksdbjava_javadocs_jar rocksdbjava_sources_jar
 	cd java/crossbuild && (vagrant destroy -f || true) && vagrant up linux32 && vagrant halt linux32 && vagrant up linux64 && vagrant halt linux64 && vagrant up linux64-musl && vagrant halt linux64-musl
-	cd java;jar -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
-	cd java/target;jar -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
-	cd java/target/classes;jar -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
+	cd java; $(JAR_CMD) -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
 	openssl sha1 java/target/$(ROCKSDB_JAR_ALL) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR_ALL).sha1

-rocksdbjavastaticreleasedocker: rocksdbjavastatic rocksdbjavastaticdockerx86 rocksdbjavastaticdockerx86_64 rocksdbjavastaticdockerx86musl rocksdbjavastaticdockerx86_64musl
-	cd java;jar -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
-	cd java/target;jar -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
-	cd java/target/classes;jar -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
+rocksdbjavastaticreleasedocker: rocksdbjavastaticosx rocksdbjavastaticdockerx86 rocksdbjavastaticdockerx86_64 rocksdbjavastaticdockerx86musl rocksdbjavastaticdockerx86_64musl rocksdbjava_javadocs_jar rocksdbjava_sources_jar
+	cd java; $(JAR_CMD) -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
 	openssl sha1 java/target/$(ROCKSDB_JAR_ALL) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR_ALL).sha1

 rocksdbjavastaticdockerx86:
@@ -2157,40 +2291,54 @@ rocksdbjavastaticdockerarm64v8:
 	mkdir -p java/target
 	docker run --rm --name rocksdb_linux_arm64v8-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:centos7_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh

+rocksdbjavastaticdockers390x:
+	mkdir -p java/target
+	docker run --rm --name rocksdb_linux_s390x-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:ubuntu18_s390x-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh
+
 rocksdbjavastaticdockerx86musl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_x86-musl-be --platform linux/386 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_x86-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh
+	docker run --rm --name rocksdb_linux_x86-musl-be --platform linux/386 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_x86-be /rocksdb-host/java/crossbuild/docker-build-linux-alpine.sh

 rocksdbjavastaticdockerx86_64musl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_x64-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_x64-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh
+	docker run --rm --name rocksdb_linux_x64-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_x64-be /rocksdb-host/java/crossbuild/docker-build-linux-alpine.sh

 rocksdbjavastaticdockerppc64lemusl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_ppc64le-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_ppc64le-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh
+	docker run --rm --name rocksdb_linux_ppc64le-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_ppc64le-be /rocksdb-host/java/crossbuild/docker-build-linux-alpine.sh

 rocksdbjavastaticdockerarm64v8musl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_arm64v8-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh
+	docker run --rm --name rocksdb_linux_arm64v8-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux-alpine.sh
+
+rocksdbjavastaticdockers390xmusl:
+	mkdir -p java/target
+	docker run --rm --name rocksdb_linux_s390x-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) evolvedbinary/rocksjava:alpine3_s390x-be /rocksdb-host/java/crossbuild/docker-build-linux-alpine.sh

 rocksdbjavastaticpublish: rocksdbjavastaticrelease rocksdbjavastaticpublishcentral

 rocksdbjavastaticpublishdocker: rocksdbjavastaticreleasedocker rocksdbjavastaticpublishcentral

+ROCKSDB_JAVA_RELEASE_CLASSIFIERS = javadoc sources linux64 linux32 linux64-musl linux32-musl osx win64
+
 rocksdbjavastaticpublishcentral: rocksdbjavageneratepom
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-javadoc.jar -Dclassifier=javadoc
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-sources.jar -Dclassifier=sources
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-linux64.jar -Dclassifier=linux64
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-linux32.jar -Dclassifier=linux32
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-linux64-musl.jar -Dclassifier=linux64-musl
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-linux32-musl.jar -Dclassifier=linux32-musl
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-osx.jar -Dclassifier=osx
-	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-win64.jar -Dclassifier=win64
 	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar
+	$(foreach classifier, $(ROCKSDB_JAVA_RELEASE_CLASSIFIERS), mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/pom.xml -Dfile=java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar -Dclassifier=$(classifier);)

 rocksdbjavageneratepom:
 	cd java;cat pom.xml.template | sed 's/\$${ROCKSDB_JAVA_VERSION}/$(ROCKSDB_JAVA_VERSION)/' > pom.xml

+rocksdbjavastaticnexusbundlejar: rocksdbjavageneratepom
+	openssl sha1 -r java/pom.xml | awk '{  print $$1 }' > java/target/pom.xml.sha1
+	openssl sha1 -r java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar | awk '{  print $$1 }' > java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar.sha1
+	$(foreach classifier, $(ROCKSDB_JAVA_RELEASE_CLASSIFIERS), openssl sha1 -r java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar | awk '{  print $$1 }' > java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar.sha1;)
+	gpg --yes --output java/target/pom.xml.asc -ab java/pom.xml
+	gpg --yes -ab java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar
+	$(foreach classifier, $(ROCKSDB_JAVA_RELEASE_CLASSIFIERS), gpg --yes -ab java/target/rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar;)
+	$(JAR_CMD) cvf java/target/nexus-bundle-rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar -C java pom.xml -C java/target pom.xml.sha1 -C java/target pom.xml.asc -C java/target rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar -C java/target rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar.sha1 -C java/target rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar.asc
+	$(foreach classifier, $(ROCKSDB_JAVA_RELEASE_CLASSIFIERS), $(JAR_CMD) uf java/target/nexus-bundle-rocksdbjni-$(ROCKSDB_JAVA_VERSION).jar -C java/target rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar -C java/target rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar.sha1 -C java/target rocksdbjni-$(ROCKSDB_JAVA_VERSION)-$(classifier).jar.asc;)
+
+
 # A version of each $(LIBOBJECTS) compiled with -fPIC

 jl/%.o: %.cc
@@ -2202,10 +2350,10 @@ ifeq ($(JAVA_HOME),)
 endif
 	$(AM_V_GEN)cd java; SHA256_CMD='$(SHA256_CMD)' $(MAKE) javalib;
 	$(AM_V_at)rm -f ./java/target/$(ROCKSDBJNILIB)
-	$(AM_V_at)$(CXX) $(CXXFLAGS) -I./java/. $(JAVA_INCLUDE) -shared -fPIC -o ./java/target/$(ROCKSDBJNILIB) $(JNI_NATIVE_SOURCES) $(LIB_OBJECTS) $(JAVA_LDFLAGS) $(COVERAGEFLAGS)
-	$(AM_V_at)cd java;jar -cf target/$(ROCKSDB_JAR) HISTORY*.md
-	$(AM_V_at)cd java/target;jar -uf $(ROCKSDB_JAR) $(ROCKSDBJNILIB)
-	$(AM_V_at)cd java/target/classes;jar -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
+	$(AM_V_at)$(CXX) $(CXXFLAGS) -I./java/. -I./java/rocksjni $(JAVA_INCLUDE) $(ROCKSDB_PLUGIN_JNI_CXX_INCLUDEFLAGS) -shared -fPIC -o ./java/target/$(ROCKSDBJNILIB) $(ALL_JNI_NATIVE_SOURCES) $(LIB_OBJECTS) $(JAVA_LDFLAGS) $(COVERAGEFLAGS)
+	$(AM_V_at)cd java; $(JAR_CMD) -cf target/$(ROCKSDB_JAR) HISTORY*.md
+	$(AM_V_at)cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) $(ROCKSDBJNILIB)
+	$(AM_V_at)cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
 	$(AM_V_at)openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1

 jclean:
@@ -2224,10 +2372,10 @@ jtest: rocksdbjava
 jdb_bench:
 	cd java;$(MAKE) db_bench;

-commit_prereq: build_tools/rocksdb-lego-determinator \
-               build_tools/precommit_checker.py
-	J=$(J) build_tools/precommit_checker.py unit unit_481 clang_unit release release_481 clang_release tsan asan ubsan lite unit_non_shm
-	$(MAKE) clean && $(MAKE) jclean && $(MAKE) rocksdbjava;
+commit_prereq:
+	echo "TODO: bring this back using parts of old precommit_checker.py and rocksdb-lego-determinator"
+	false # J=$(J) build_tools/precommit_checker.py unit clang_unit release clang_release tsan asan ubsan lite unit_non_shm
+	# $(MAKE) clean && $(MAKE) jclean && $(MAKE) rocksdbjava;

 # ---------------------------------------------------------------------------
 #  	Platform-specific compilation
@@ -2324,9 +2472,12 @@ endif
 build_subset_tests: $(ROCKSDBTESTS_SUBSET)
 	$(AM_V_GEN)if [ -n "$${ROCKSDBTESTS_SUBSET_TESTS_TO_FILE}" ]; then echo "$(ROCKSDBTESTS_SUBSET)" > "$${ROCKSDBTESTS_SUBSET_TESTS_TO_FILE}"; else echo "$(ROCKSDBTESTS_SUBSET)"; fi

+list_all_tests:
+	echo "$(ROCKSDBTESTS_SUBSET)"
+
 # Remove the rules for which dependencies should not be generated and see if any are left.
 #If so, include the dependencies; if not, do not include the dependency files
-ROCKS_DEP_RULES=$(filter-out clean format check-format check-buck-targets jclean jtest package analyze tags rocksdbjavastatic% unity.% unity_test, $(MAKECMDGOALS))
+ROCKS_DEP_RULES=$(filter-out clean format check-format check-buck-targets check-headers check-sources jclean jtest package analyze tags rocksdbjavastatic% unity.% unity_test, $(MAKECMDGOALS))
 ifneq ("$(ROCKS_DEP_RULES)", "")
 -include $(DEPFILES)
 endif
@@ -1,4 +1,6 @@
 This is the list of all known third-party plugins for RocksDB. If something is missing, please open a pull request to add it.

 * [Dedupfs](https://github.com/ajkr/dedupfs): an example for plugin developers to reference
+* [HDFS](https://github.com/riversand963/rocksdb-hdfs-env): an Env used for interacting with HDFS. Migrated from main RocksDB repo
 * [ZenFS](https://github.com/westerndigitalcorporation/zenfs): a file system for zoned block devices
+* [RADOS](https://github.com/riversand963/rocksdb-rados-env): an Env used for interacting with RADOS. Migrated from RocksDB main repo.
@@ -1,8 +1,8 @@
 ## RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

 [![CircleCI Status](https://circleci.com/gh/facebook/rocksdb.svg?style=svg)](https://circleci.com/gh/facebook/rocksdb)
-[![TravisCI Status](https://travis-ci.org/facebook/rocksdb.svg?branch=master)](https://travis-ci.org/facebook/rocksdb)
-[![Appveyor Build status](https://ci.appveyor.com/api/projects/status/fbgfu0so3afcno78/branch/master?svg=true)](https://ci.appveyor.com/project/Facebook/rocksdb/branch/master)
+[![TravisCI Status](https://api.travis-ci.com/facebook/rocksdb.svg?branch=main)](https://travis-ci.com/github/facebook/rocksdb)
+[![Appveyor Build status](https://ci.appveyor.com/api/projects/status/fbgfu0so3afcno78/branch/main?svg=true)](https://ci.appveyor.com/project/Facebook/rocksdb/branch/main)
 [![PPC64le Build Status](http://140-211-168-68-openstack.osuosl.org:8080/buildStatus/icon?job=rocksdb&style=plastic)](http://140-211-168-68-openstack.osuosl.org:8080/job/rocksdb)

 RocksDB is developed and maintained by Facebook Database Engineering Team.
@@ -17,7 +17,7 @@ and Space-Amplification-Factor (SAF). It has multi-threaded compactions,
 making it especially suitable for storing multiple terabytes of data in a
 single database.

-Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples
+Start with example usage here: https://github.com/facebook/rocksdb/tree/main/examples

 See the [github wiki](https://github.com/facebook/rocksdb/wiki) for more explanation.

@@ -25,7 +25,7 @@ The public interface is in `include/`.  Callers should not include or
 rely on the details of any other header files in this package.  Those
 internal APIs may be changed without warning.

-Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/ and https://rocksdb.slack.com/
+Questions and discussions are welcome on the [RocksDB Developers Public](https://www.facebook.com/groups/rocksdb.dev/) Facebook group and [email list](https://groups.google.com/g/rocksdb) on Google Groups.

 ## License

@@ -4,7 +4,7 @@ RocksDBLite is a project focused on mobile use cases, which don't need a lot of

 Some examples of the features disabled by ROCKSDB_LITE:
 * compiled-in support for LDB tool
-* No backupable DB
+* No backup engine
 * No support for replication (which we provide in form of TransactionalIterator)
 * No advanced monitoring tools
 * No special-purpose memtables that are highly optimized for specific use cases
@@ -113,5 +113,16 @@ LzLabs is using RocksDB as a storage engine in their multi-database distributed
 [YugabyteDB](https://www.yugabyte.com/) is an open source, high performance, distributed SQL database that uses RocksDB as its storage layer. For more information, please see https://github.com/yugabyte/yugabyte-db/.

 ## ArangoDB
-[ArangoDB](https://www.arangodb.com/) is a native multi-model database with flexible data models for documents, graphs, and key-values, for building high performance applications using a convenient SQL-like query language or JavaScript extensions. It uses RocksDB as its sotrage engine.
+[ArangoDB](https://www.arangodb.com/) is a native multi-model database with flexible data models for documents, graphs, and key-values, for building high performance applications using a convenient SQL-like query language or JavaScript extensions. It uses RocksDB as its storage engine.

+## Milvus
+[Milvus](https://milvus.io/) is an open source vector database for unstructured data. It uses RocksDB not only as one of the supported kv storage engines, but also as a message queue.
+
+## Kafka
+[Kafka](https://kafka.apache.org/) is an open-source distributed event streaming platform, it uses RocksDB to store state in Kafka Streams: https://www.confluent.io/blog/how-to-tune-rocksdb-kafka-streams-state-stores-performance/.
+
+## Solana Labs
+[Solana](https://github.com/solana-labs/solana) is a fast, secure, scalable, and decentralized blockchain.  It uses RocksDB as the underlying storage for its ledger store.
+
+## Others
+More databases using RocksDB can be found at [dbdb.io](https://dbdb.io/browse?embeds=rocksdb).
@@ -24,7 +24,7 @@ We strive to achieve the following goals:
 * make all unit test pass both in debug and release builds. 
  * Note: latest introduction of SyncPoint seems to disable running db_test in Release.
 * make performance on par with published benchmarks accounting for HW differences
-* we would like to keep the port code inline with the master branch with no forking
+* we would like to keep the port code inline with the main branch with no forking

 ## Build system
 We have chosen CMake as a widely accepted build system to build the Windows port. It is very fast and convenient. 
@@ -66,7 +66,7 @@ We endeavored to make it functionally on par with posix_env. This means we repli
 Even though Windows provides its own efficient thread-pool implementation we chose to replicate posix logic using `std::thread` primitives. This allows anyone to quickly detect any changes within the posix source code and replicate them within windows env. This has proven to work very well. At the same time for anyone who wishes to replace the built-in thread-pool can do so using RocksDB stackable environments.

 For disk access we implemented all of the functionality present within the posix_env which includes memory mapped files, random access, rate-limiter support etc.
-The `use_os_buffer` flag on Posix platforms currently denotes disabling read-ahead log via `fadvise` mechanism. Windows does not have `fadvise` system call. What is more, it implements disk cache in a way that differs from Linux greatly. It’s not an uncommon practice on Windows to perform un-buffered disk access to gain control of the memory consumption. We think that in our use case this may also be a good configuration option at the expense of disk throughput. To compensate one may increase the configured in-memory cache size instead. Thus we have chosen  `use_os_buffer=false` to disable OS disk buffering for `WinWritableFile` and `WinRandomAccessFile`. The OS imposes restrictions on the alignment of the disk offsets, buffers used and the amount of data that is read/written when accessing files in un-buffered mode. When the option is true, the classes behave in a standard way. This allows to perform writes and reads in cases when un-buffered access does not make sense such as WAL and MANIFEST.
+The `use_os_buffer` flag on Posix platforms currently denotes disabling read-ahead log via `fadvise` mechanism. Windows does not have `fadvise` system call. What is more, it implements disk cache in a way that differs from Linux greatly. It's not an uncommon practice on Windows to perform un-buffered disk access to gain control of the memory consumption. We think that in our use case this may also be a good configuration option at the expense of disk throughput. To compensate one may increase the configured in-memory cache size instead. Thus we have chosen  `use_os_buffer=false` to disable OS disk buffering for `WinWritableFile` and `WinRandomAccessFile`. The OS imposes restrictions on the alignment of the disk offsets, buffers used and the amount of data that is read/written when accessing files in un-buffered mode. When the option is true, the classes behave in a standard way. This allows to perform writes and reads in cases when un-buffered access does not make sense such as WAL and MANIFEST.

 We have replaced `pread/pwrite` with `WriteFile/ReadFile` with `OVERLAPPED` structure so we can atomically seek to the position of the disk operation but still perform the operation synchronously. Thus we able to emulate that functionality of `pread/pwrite` reasonably well. The only difference is that the file pointer is not returned to its original position but that hardly matters given the random nature of access.

@@ -1,77 +0,0 @@
-version: 1.0.{build}
-
-image: Visual Studio 2019
-
-environment:
-  JAVA_HOME: C:\Program Files\Java\jdk1.8.0
-  THIRDPARTY_HOME: $(APPVEYOR_BUILD_FOLDER)\thirdparty
-  SNAPPY_HOME: $(THIRDPARTY_HOME)\snappy-1.1.7
-  SNAPPY_INCLUDE: $(SNAPPY_HOME);$(SNAPPY_HOME)\build
-  SNAPPY_LIB_DEBUG: $(SNAPPY_HOME)\build\Debug\snappy.lib
-  SNAPPY_LIB_RELEASE: $(SNAPPY_HOME)\build\Release\snappy.lib
-  LZ4_HOME: $(THIRDPARTY_HOME)\lz4-1.8.3
-  LZ4_INCLUDE: $(LZ4_HOME)\lib
-  LZ4_LIB_DEBUG: $(LZ4_HOME)\visual\VS2010\bin\x64_Debug\liblz4_static.lib
-  LZ4_LIB_RELEASE: $(LZ4_HOME)\visual\VS2010\bin\x64_Release\liblz4_static.lib
-  ZSTD_HOME: $(THIRDPARTY_HOME)\zstd-1.4.0
-  ZSTD_INCLUDE: $(ZSTD_HOME)\lib;$(ZSTD_HOME)\lib\dictBuilder
-  ZSTD_LIB_DEBUG: $(ZSTD_HOME)\build\VS2010\bin\x64_Debug\libzstd_static.lib
-  ZSTD_LIB_RELEASE: $(ZSTD_HOME)\build\VS2010\bin\x64_Release\libzstd_static.lib
-  matrix:
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      CMAKE_GENERATOR: Visual Studio 14 Win64
-      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\devenv.com
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      CMAKE_GENERATOR: Visual Studio 15 Win64
-      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.com
-
-install:
-  - md %THIRDPARTY_HOME%
-  - echo "Building Snappy dependency..."
-  - cd %THIRDPARTY_HOME%
-  - curl --fail --silent --show-error --output snappy-1.1.7.zip --location https://github.com/google/snappy/archive/1.1.7.zip
-  - unzip snappy-1.1.7.zip
-  - cd snappy-1.1.7
-  - mkdir build
-  - cd build
-  - if DEFINED CMAKE_PLATEFORM_NAME (set "PLATEFORM_OPT=-A %CMAKE_PLATEFORM_NAME%")
-  - cmake .. -G "%CMAKE_GENERATOR%" %PLATEFORM_OPT%
-  - msbuild Snappy.sln /p:Configuration=Debug /p:Platform=x64
-  - msbuild Snappy.sln /p:Configuration=Release /p:Platform=x64
-  - echo "Building LZ4 dependency..."
-  - cd %THIRDPARTY_HOME%
-  - curl --fail --silent --show-error --output lz4-1.8.3.zip --location https://github.com/lz4/lz4/archive/v1.8.3.zip
-  - unzip lz4-1.8.3.zip
-  - cd lz4-1.8.3\visual\VS2010
-  - ps: $CMD="$Env:DEV_ENV"; & $CMD lz4.sln /upgrade
-  - msbuild lz4.sln /p:Configuration=Debug /p:Platform=x64
-  - msbuild lz4.sln /p:Configuration=Release /p:Platform=x64
-  - echo "Building ZStd dependency..."
-  - cd %THIRDPARTY_HOME%
-  - curl --fail --silent --show-error --output zstd-1.4.0.zip --location https://github.com/facebook/zstd/archive/v1.4.0.zip
-  - unzip zstd-1.4.0.zip
-  - cd zstd-1.4.0\build\VS2010
-  - ps: $CMD="$Env:DEV_ENV"; & $CMD zstd.sln /upgrade
-  - msbuild zstd.sln /p:Configuration=Debug /p:Platform=x64
-  - msbuild zstd.sln /p:Configuration=Release /p:Platform=x64
-
-before_build:
-  - md %APPVEYOR_BUILD_FOLDER%\build
-  - cd %APPVEYOR_BUILD_FOLDER%\build
-  - if DEFINED CMAKE_PLATEFORM_NAME (set "PLATEFORM_OPT=-A %CMAKE_PLATEFORM_NAME%")
-  - cmake .. -G "%CMAKE_GENERATOR%" %PLATEFORM_OPT% %CMAKE_OPT% -DCMAKE_BUILD_TYPE=Debug -DOPTDBG=1 -DPORTABLE=1 -DSNAPPY=1 -DLZ4=1 -DZSTD=1 -DXPRESS=1 -DJNI=1 -DWITH_ALL_TESTS=0
-  - cd ..
-
-build:
-  project: build\rocksdb.sln
-  parallel: true
-  verbosity: normal
-
-test:
-
-test_script:
-  - ps: build_tools\run_ci_db_test.ps1 -SuiteRun db_basic_test,env_basic_test -Concurrency 8
-
-on_failure:
-  - cmd: 7z a build-failed.zip %APPVEYOR_BUILD_FOLDER%\build\ && appveyor PushArtifact build-failed.zip
-
@@ -163,9 +163,8 @@ def generate_targets(repo_path, deps_map):
        src_mk.get("EXP_LIB_SOURCES", []) +
        src_mk.get("ANALYZER_LIB_SOURCES", []),
        [":rocksdb_lib"],
-        extra_external_deps=""" + [
-        ("googletest", None, "gtest"),
-    ]""")
+        extra_test_libs=True
+        )
    # rocksdb_tools_lib
    TARGETS.add_library(
        "rocksdb_tools_lib",
@@ -173,18 +172,30 @@ def generate_targets(repo_path, deps_map):
        src_mk.get("ANALYZER_LIB_SOURCES", []) +
        ["test_util/testutil.cc"],
        [":rocksdb_lib"])
+    # rocksdb_cache_bench_tools_lib
+    TARGETS.add_library(
+        "rocksdb_cache_bench_tools_lib",
+        src_mk.get("CACHE_BENCH_LIB_SOURCES", []),
+        [":rocksdb_lib"])
    # rocksdb_stress_lib
    TARGETS.add_rocksdb_library(
        "rocksdb_stress_lib",
        src_mk.get("ANALYZER_LIB_SOURCES", [])
        + src_mk.get('STRESS_LIB_SOURCES', [])
        + ["test_util/testutil.cc"])
-
+    # bench binaries
+    for src in src_mk.get("MICROBENCH_SOURCES", []):
+        name =  src.rsplit('/',1)[1].split('.')[0] if '/' in src else src.split('.')[0]
+        TARGETS.add_binary(
+            name,
+            [src],
+            [],
+            extra_bench_libs=True
+            )
    print("Extra dependencies:\n{0}".format(json.dumps(deps_map)))

    # Dictionary test executable name -> relative source file path
    test_source_map = {}
-    print(src_mk)

    # c_test.c is added through TARGETS.add_c_test(). If there
    # are more than one .c test file, we need to extend
@@ -195,6 +206,42 @@ def generate_targets(repo_path, deps_map):
            return False
    TARGETS.add_c_test()

+    try:
+        with open(f"{repo_path}/buckifier/bench.json") as json_file:
+            fast_fancy_bench_config_list = json.load(json_file)
+            for config_dict in fast_fancy_bench_config_list:
+                clean_benchmarks = {}
+                benchmarks = config_dict['benchmarks']
+                for binary, benchmark_dict in benchmarks.items():
+                    clean_benchmarks[binary] = {}
+                    for benchmark, overloaded_metric_list in benchmark_dict.items():
+                        clean_benchmarks[binary][benchmark] = []
+                        for metric in overloaded_metric_list:
+                            if not isinstance(metric, dict):
+                                clean_benchmarks[binary][benchmark].append(metric)
+                TARGETS.add_fancy_bench_config(config_dict['name'], clean_benchmarks, False, config_dict['expected_runtime_one_iter'], config_dict['sl_iterations'], config_dict['regression_threshold'])
+
+        with open(f"{repo_path}/buckifier/bench-slow.json") as json_file:
+            slow_fancy_bench_config_list = json.load(json_file)
+            for config_dict in slow_fancy_bench_config_list:
+                clean_benchmarks = {}
+                benchmarks = config_dict['benchmarks']
+                for binary, benchmark_dict in benchmarks.items():
+                    clean_benchmarks[binary] = {}
+                    for benchmark, overloaded_metric_list in benchmark_dict.items():
+                        clean_benchmarks[binary][benchmark] = []
+                        for metric in overloaded_metric_list:
+                            if not isinstance(metric, dict):
+                                clean_benchmarks[binary][benchmark].append(metric)
+            for config_dict in slow_fancy_bench_config_list:
+                TARGETS.add_fancy_bench_config(config_dict['name']+"_slow", clean_benchmarks, True, config_dict['expected_runtime_one_iter'], config_dict['sl_iterations'], config_dict['regression_threshold'])
+    # it is better servicelab experiments break
+    # than rocksdb github ci
+    except Exception:
+        pass
+
+    TARGETS.add_test_header()
+
    for test_src in src_mk.get("TEST_MAIN_SOURCES", []):
        test = test_src.split('.c')[0].strip().split('/')[-1].strip()
        test_source_map[test] = test_src
@@ -208,17 +255,21 @@ def generate_targets(repo_path, deps_map):

            test_target_name = \
                test if not target_alias else test + "_" + target_alias
-            TARGETS.register_test(
-                test_target_name,
-                test_src,
-                test not in non_parallel_tests,
-                json.dumps(deps['extra_deps']),
-                json.dumps(deps['extra_compiler_flags']))

            if test in _EXPORTED_TEST_LIBS:
                test_library = "%s_lib" % test_target_name
-                TARGETS.add_library(test_library, [test_src], [":rocksdb_test_lib"])
-    TARGETS.flush_tests()
+                TARGETS.add_library(test_library, [test_src], deps=[":rocksdb_test_lib"], extra_test_libs=True)
+                TARGETS.register_test(
+                    test_target_name,
+                    test_src,
+                    deps = json.dumps(deps['extra_deps'] + [':'+test_library]),
+                    extra_compiler_flags = json.dumps(deps['extra_compiler_flags']))
+            else:
+                TARGETS.register_test(
+                    test_target_name,
+                    test_src,
+                    deps = json.dumps(deps['extra_deps'] + [":rocksdb_test_lib"] ),
+                    extra_compiler_flags = json.dumps(deps['extra_compiler_flags']))

    print(ColorString.info("Generated TARGETS Summary:"))
    print(ColorString.info("- %d libs" % TARGETS.total_lib))
@@ -10,6 +10,7 @@ except ImportError:
    from __builtin__ import object
    from __builtin__ import str
 import targets_cfg
+import pprint

 def pretty_list(lst, indent=8):
    if lst is None or len(lst) == 0:
@@ -40,85 +41,73 @@ class TARGETSBuilder(object):
        self.targets_file.close()

    def add_library(self, name, srcs, deps=None, headers=None,
-                    extra_external_deps="", link_whole=False):
-        headers_attr_prefix = ""
-        if headers is None:
-            headers_attr_prefix = "auto_"
-            headers = "AutoHeaders.RECURSIVE_GLOB"
-        else:
+                    extra_external_deps="", link_whole=False,
+                     external_dependencies=None, extra_test_libs=False):
+        if headers is not None:
            headers = "[" + pretty_list(headers) + "]"
        self.targets_file.write(targets_cfg.library_template.format(
            name=name,
            srcs=pretty_list(srcs),
-            headers_attr_prefix=headers_attr_prefix,
            headers=headers,
            deps=pretty_list(deps),
            extra_external_deps=extra_external_deps,
-            link_whole=link_whole).encode("utf-8"))
+            link_whole=link_whole,
+            external_dependencies=pretty_list(external_dependencies),
+            extra_test_libs=extra_test_libs
+            ).encode("utf-8"))
        self.total_lib = self.total_lib + 1

-    def add_rocksdb_library(self, name, srcs, headers=None):
-        headers_attr_prefix = ""
-        if headers is None:
-            headers_attr_prefix = "auto_"
-            headers = "AutoHeaders.RECURSIVE_GLOB"
-        else:
+    def add_rocksdb_library(self, name, srcs, headers=None,
+                            external_dependencies=None):
+        if headers is not None:
            headers = "[" + pretty_list(headers) + "]"
        self.targets_file.write(targets_cfg.rocksdb_library_template.format(
            name=name,
            srcs=pretty_list(srcs),
-            headers_attr_prefix=headers_attr_prefix,
-            headers=headers).encode("utf-8"))
+            headers=headers,
+            external_dependencies=pretty_list(external_dependencies)
+            ).encode("utf-8")
+            )
        self.total_lib = self.total_lib + 1

-    def add_binary(self, name, srcs, deps=None):
+    def add_binary(self, name, srcs, deps=None, extra_preprocessor_flags=None,extra_bench_libs=False):
        self.targets_file.write(targets_cfg.binary_template.format(
            name=name,
            srcs=pretty_list(srcs),
-            deps=pretty_list(deps)).encode("utf-8"))
+            deps=pretty_list(deps),
+            extra_preprocessor_flags=pretty_list(extra_preprocessor_flags),
+            extra_bench_libs=extra_bench_libs,
+            ).encode("utf-8"))
        self.total_bin = self.total_bin + 1

    def add_c_test(self):
        self.targets_file.write(b"""
-cpp_binary(
-    name = "c_test_bin",
-    srcs = ["db/c_test.c"],
-    arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
-    compiler_flags = ROCKSDB_COMPILER_FLAGS,
-    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-    include_paths = ROCKSDB_INCLUDE_PATHS,
-    deps = [":rocksdb_test_lib"],
-) if not is_opt_mode else None
-
-custom_unittest(
-    name = "c_test",
-    command = [
-        native.package_name() + "/buckifier/rocks_test_runner.sh",
-        "$(location :{})".format("c_test_bin"),
-    ],
-    type = "simple",
-) if not is_opt_mode else None
+add_c_test_wrapper()
 """)

+    def add_test_header(self):
+        self.targets_file.write(b"""
+        # Generate a test rule for each entry in ROCKS_TESTS
+        # Do not build the tests in opt mode, since SyncPoint and other test code
+        # will not be included.
+""")
+
+    def add_fancy_bench_config(self, name, bench_config, slow, expected_runtime, sl_iterations, regression_threshold):
+        self.targets_file.write(targets_cfg.fancy_bench_template.format(
+                    name=name,
+                    bench_config=pprint.pformat(bench_config),
+                    slow=slow,
+                    expected_runtime=expected_runtime,
+                    sl_iterations=sl_iterations,
+                    regression_threshold=regression_threshold
+                    ).encode("utf-8"))
+
    def register_test(self,
                      test_name,
                      src,
-                      is_parallel,
-                      extra_deps,
+                      deps,
                      extra_compiler_flags):
-        exec_mode = "serial"
-        if is_parallel:
-            exec_mode = "parallel"
-        self.tests_cfg += targets_cfg.test_cfg_template % (
-            test_name,
-            str(src),
-            str(exec_mode),
-            extra_deps,
-            extra_compiler_flags)

+        self.targets_file.write(targets_cfg.unittests_template.format(test_name=test_name,test_cc=str(src),deps=deps,
+            extra_compiler_flags=extra_compiler_flags).encode("utf-8"))
        self.total_test = self.total_test + 1
-
-    def flush_tests(self):
-        self.targets_file.write(targets_cfg.unittests_template.format(tests=self.tests_cfg).encode("utf-8"))
-        self.tests_cfg = ""
@@ -11,210 +11,36 @@ rocksdb_target_header_template = \
 # This file is a Facebook-specific integration for buck builds, so can
 # only be validated by Facebook employees.
 #
-load("@fbcode_macros//build_defs:auto_headers.bzl", "AutoHeaders")
-load("@fbcode_macros//build_defs:cpp_library.bzl", "cpp_library")
-load(":defs.bzl", "test_binary")
+# @noautodeps @nocodemods
+load("//rocks/buckifier:defs.bzl", "cpp_library_wrapper","rocks_cpp_library_wrapper","cpp_binary_wrapper","cpp_unittest_wrapper","fancy_bench_wrapper","add_c_test_wrapper")

-REPO_PATH = package_name() + "/"
-
-ROCKSDB_COMPILER_FLAGS = [
-    "-fno-builtin-memcmp",
-    # Needed to compile in fbcode
-    "-Wno-expansion-to-defined",
-    # Added missing flags from output of build_detect_platform
-    "-Wnarrowing",
-    "-DROCKSDB_NO_DYNAMIC_EXTENSION",
-]
-
-ROCKSDB_EXTERNAL_DEPS = [
-    ("bzip2", None, "bz2"),
-    ("snappy", None, "snappy"),
-    ("zlib", None, "z"),
-    ("gflags", None, "gflags"),
-    ("lz4", None, "lz4"),
-    ("zstd", None, "zstd"),
-]
-
-ROCKSDB_OS_DEPS = [
-    (
-        "linux",
-        ["third-party//numa:numa", "third-party//liburing:uring", "third-party//tbb:tbb"],
-    ),
-    (
-        "macos",
-        ["third-party//tbb:tbb"],
-    ),
-]
-
-ROCKSDB_OS_PREPROCESSOR_FLAGS = [
-    (
-        "linux",
-        [
-            "-DOS_LINUX",
-            "-DROCKSDB_FALLOCATE_PRESENT",
-            "-DROCKSDB_MALLOC_USABLE_SIZE",
-            "-DROCKSDB_PTHREAD_ADAPTIVE_MUTEX",
-            "-DROCKSDB_RANGESYNC_PRESENT",
-            "-DROCKSDB_SCHED_GETCPU_PRESENT",
-            "-DROCKSDB_IOURING_PRESENT",
-            "-DHAVE_SSE42",
-            "-DLIBURING",
-            "-DNUMA",
-            "-DROCKSDB_PLATFORM_POSIX",
-            "-DROCKSDB_LIB_IO_POSIX",
-            "-DTBB",
-        ],
-    ),
-    (
-        "macos",
-        [
-            "-DOS_MACOSX",
-            "-DROCKSDB_PLATFORM_POSIX",
-            "-DROCKSDB_LIB_IO_POSIX",
-            "-DTBB",
-        ],
-    ),
-    (
-        "windows",
-        [ "-DOS_WIN", "-DWIN32", "-D_MBCS", "-DWIN64", "-DNOMINMAX" ]
-    ),
-]
-
-ROCKSDB_PREPROCESSOR_FLAGS = [
-    "-DROCKSDB_SUPPORT_THREAD_LOCAL",
-
-    # Flags to enable libs we include
-    "-DSNAPPY",
-    "-DZLIB",
-    "-DBZIP2",
-    "-DLZ4",
-    "-DZSTD",
-    "-DZSTD_STATIC_LINKING_ONLY",
-    "-DGFLAGS=gflags",
-
-    # Added missing flags from output of build_detect_platform
-    "-DROCKSDB_BACKTRACE",
-]
-
-# Directories with files for #include
-ROCKSDB_INCLUDE_PATHS = [
-    "",
-    "include",
-]
-
-ROCKSDB_ARCH_PREPROCESSOR_FLAGS = {{
-    "x86_64": [
-        "-DHAVE_PCLMUL",
-    ],
-}}
-
-build_mode = read_config("fbcode", "build_mode")
-
-is_opt_mode = build_mode.startswith("opt")
-
-# -DNDEBUG is added by default in opt mode in fbcode. But adding it twice
-# doesn't harm and avoid forgetting to add it.
-ROCKSDB_COMPILER_FLAGS += (["-DNDEBUG"] if is_opt_mode else [])
-
-sanitizer = read_config("fbcode", "sanitizer")
-
-# Do not enable jemalloc if sanitizer presents. RocksDB will further detect
-# whether the binary is linked with jemalloc at runtime.
-ROCKSDB_OS_PREPROCESSOR_FLAGS += ([(
-    "linux",
-    ["-DROCKSDB_JEMALLOC"],
-)] if sanitizer == "" else [])
-
-ROCKSDB_OS_DEPS += ([(
-    "linux",
-    ["third-party//jemalloc:headers"],
-)] if sanitizer == "" else [])
-
-ROCKSDB_LIB_DEPS = [
-    ":rocksdb_lib",
-    ":rocksdb_test_lib",
-] if not is_opt_mode else [":rocksdb_lib"]
 """


 library_template = """
-cpp_library(
-    name = "{name}",
-    srcs = [{srcs}],
-    {headers_attr_prefix}headers = {headers},
-    arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-    compiler_flags = ROCKSDB_COMPILER_FLAGS,
-    os_deps = ROCKSDB_OS_DEPS,
-    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
-    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-    include_paths = ROCKSDB_INCLUDE_PATHS,
-    deps = [{deps}],
-    external_deps = ROCKSDB_EXTERNAL_DEPS{extra_external_deps},
-    link_whole = {link_whole},
-)
+cpp_library_wrapper(name="{name}", srcs=[{srcs}], deps=[{deps}], headers={headers}, link_whole={link_whole}, extra_test_libs={extra_test_libs})
 """

 rocksdb_library_template = """
-cpp_library(
-    name = "{name}",
-    srcs = [{srcs}],
-    {headers_attr_prefix}headers = {headers},
-    arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-    compiler_flags = ROCKSDB_COMPILER_FLAGS,
-    os_deps = ROCKSDB_OS_DEPS,
-    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
-    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-    include_paths = ROCKSDB_INCLUDE_PATHS,
-    deps = ROCKSDB_LIB_DEPS,
-    external_deps = ROCKSDB_EXTERNAL_DEPS,
-)
+rocks_cpp_library_wrapper(name="{name}", srcs=[{srcs}], headers={headers})
+
 """

+
+
 binary_template = """
-cpp_binary(
-    name = "{name}",
-    srcs = [{srcs}],
-    arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-    compiler_flags = ROCKSDB_COMPILER_FLAGS,
-    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-    include_paths = ROCKSDB_INCLUDE_PATHS,
-    deps = [{deps}],
-    external_deps = ROCKSDB_EXTERNAL_DEPS,
-)
-"""
-
-test_cfg_template = """    [
-        "%s",
-        "%s",
-        "%s",
-        %s,
-        %s,
-    ],
+cpp_binary_wrapper(name="{name}", srcs=[{srcs}], deps=[{deps}], extra_preprocessor_flags=[{extra_preprocessor_flags}], extra_bench_libs={extra_bench_libs})
 """

 unittests_template = """
-# [test_name, test_src, test_type, extra_deps, extra_compiler_flags]
-ROCKS_TESTS = [
-{tests}]
+cpp_unittest_wrapper(name="{test_name}",
+            srcs=["{test_cc}"],
+            deps={deps},
+            extra_compiler_flags={extra_compiler_flags})
+
+"""
+
+fancy_bench_template = """
+fancy_bench_wrapper(suite_name="{name}", binary_to_bench_to_metric_list_map={bench_config}, slow={slow}, expected_runtime={expected_runtime}, sl_iterations={sl_iterations}, regression_threshold={regression_threshold})

-# Generate a test rule for each entry in ROCKS_TESTS
-# Do not build the tests in opt mode, since SyncPoint and other test code
-# will not be included.
-[
-    cpp_unittest(
-        name = test_name,
-        srcs = [test_cc],
-        arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-        os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
-        compiler_flags = ROCKSDB_COMPILER_FLAGS + extra_compiler_flags,
-        preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-        include_paths = ROCKSDB_INCLUDE_PATHS,
-        deps = [":rocksdb_test_lib"] + extra_deps,
-        external_deps = ROCKSDB_EXTERNAL_DEPS + [
-            ("googletest", None, "gtest"),
-        ],
-    )
-    for test_name, test_cc, parallelism, extra_deps, extra_compiler_flags in ROCKS_TESTS
-    if not is_opt_mode
-]
 """
@@ -45,11 +45,11 @@ if test -z "$OUTPUT"; then
  exit 1
 fi

-# we depend on C++11, but should be compatible with newer standards
+# we depend on C++17, but should be compatible with newer standards
 if [ "$ROCKSDB_CXX_STANDARD" ]; then
  PLATFORM_CXXFLAGS="-std=$ROCKSDB_CXX_STANDARD"
 else
-  PLATFORM_CXXFLAGS="-std=c++11"
+  PLATFORM_CXXFLAGS="-std=c++17"
 fi

 # we currently depend on POSIX platform
@@ -58,24 +58,12 @@ COMMON_FLAGS="-DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX"
 # Default to fbcode gcc on internal fb machines
 if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
    FBCODE_BUILD="true"
-    # If we're compiling with TSAN we need pic build
+    # If we're compiling with TSAN or shared lib, we need pic build
    PIC_BUILD=$COMPILE_WITH_TSAN
-    if [ -n "$ROCKSDB_FBCODE_BUILD_WITH_481" ]; then
-      # we need this to build with MySQL. Don't use for other purposes.
-      source "$PWD/build_tools/fbcode_config4.8.1.sh"
-    elif [ -n "$ROCKSDB_FBCODE_BUILD_WITH_5xx" ]; then
-      source "$PWD/build_tools/fbcode_config.sh"
-    elif [ -n "$ROCKSDB_FBCODE_BUILD_WITH_PLATFORM007" ]; then
-      source "$PWD/build_tools/fbcode_config_platform007.sh"
-    elif [ -n "$ROCKSDB_FBCODE_BUILD_WITH_PLATFORM009" ]; then
-      source "$PWD/build_tools/fbcode_config_platform009.sh"
-    elif [ -z "$USE_CLANG" ]; then
-        # Still use platform007 for gcc by default for build break on
-        # some hosts.
-      source "$PWD/build_tools/fbcode_config_platform007.sh"
-    else
-      source "$PWD/build_tools/fbcode_config_platform009.sh"
+    if [ "$LIB_MODE" == "shared" ]; then
+      PIC_BUILD=1
    fi
+    source "$PWD/build_tools/fbcode_config_platform009.sh"
 fi

 # Delete existing output, if it exists
@@ -175,9 +163,12 @@ case "$TARGET_OS" in
            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -latomic"
        fi
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread -lrt -ldl"
-        if test $ROCKSDB_USE_IO_URING; then
+        if test -z "$ROCKSDB_USE_IO_URING"; then
+            ROCKSDB_USE_IO_URING=1
+        fi
+        if test "$ROCKSDB_USE_IO_URING" -ne 0; then
            # check for liburing
-            $CXX $PLATFORM_CXXFLAGS -x c++ - -luring -o /dev/null 2>/dev/null  <<EOF
+            $CXX $PLATFORM_CXXFLAGS -x c++ - -luring -o test.o 2>/dev/null  <<EOF
              #include <liburing.h>
              int main() {
                struct io_uring ring;
@@ -190,9 +181,6 @@ EOF
                COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_IOURING_PRESENT"
            fi
        fi
-        if test -z "$USE_FOLLY_DISTRIBUTED_MUTEX"; then
-          USE_FOLLY_DISTRIBUTED_MUTEX=1
-        fi
        # PORT_FILES=port/linux/linux_specific.cc
        ;;
    SunOS)
@@ -275,7 +263,7 @@ esac
 PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS ${CXXFLAGS}"
 JAVA_LDFLAGS="$PLATFORM_LDFLAGS"
 JAVA_STATIC_LDFLAGS="$PLATFORM_LDFLAGS"
-JAVAC_ARGS="-source 7"
+JAVAC_ARGS="-source 8"

 if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
    # Cross-compiling; do not try any compilation tests.
@@ -288,7 +276,7 @@ if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
 else
    if ! test $ROCKSDB_DISABLE_FALLOCATE; then
        # Test whether fallocate is available
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <fcntl.h>
          #include <linux/falloc.h>
          int main() {
@@ -304,7 +292,7 @@ EOF
    if ! test $ROCKSDB_DISABLE_SNAPPY; then
        # Test whether Snappy library is installed
        # http://code.google.com/p/snappy/
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <snappy.h>
          int main() {}
 EOF
@@ -319,7 +307,7 @@ EOF
        # Test whether gflags library is installed
        # http://gflags.github.io/gflags/
        # check if the namespace is gflags
-        if $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null << EOF
+        if $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null << EOF
          #include <gflags/gflags.h>
          using namespace GFLAGS_NAMESPACE;
          int main() {}
@@ -328,7 +316,7 @@ EOF
          COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=1"
          PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
        # check if namespace is gflags
-        elif $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null << EOF
+        elif $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null << EOF
            #include <gflags/gflags.h>
            using namespace gflags;
            int main() {}
@@ -337,7 +325,7 @@ EOF
          COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=1 -DGFLAGS_NAMESPACE=gflags"
          PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
        # check if namespace is google
-        elif $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null << EOF
+        elif $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null << EOF
            #include <gflags/gflags.h>
            using namespace google;
            int main() {}
@@ -350,7 +338,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_ZLIB; then
        # Test whether zlib library is installed
-        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <zlib.h>
          int main() {}
 EOF
@@ -363,7 +351,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_BZIP; then
        # Test whether bzip library is installed
-        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <bzlib.h>
          int main() {}
 EOF
@@ -376,7 +364,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_LZ4; then
        # Test whether lz4 library is installed
-        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <lz4.h>
          #include <lz4hc.h>
          int main() {}
@@ -403,7 +391,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_NUMA; then
        # Test whether numa is available
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null -lnuma 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o -lnuma 2>/dev/null  <<EOF
          #include <numa.h>
          #include <numaif.h>
          int main() {}
@@ -417,7 +405,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_TBB; then
        # Test whether tbb is available
-        $CXX $PLATFORM_CXXFLAGS $LDFLAGS -x c++ - -o /dev/null -ltbb 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS $LDFLAGS -x c++ - -o test.o -ltbb 2>/dev/null  <<EOF
          #include <tbb/tbb.h>
          int main() {}
 EOF
@@ -430,7 +418,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_JEMALLOC; then
        # Test whether jemalloc is available
-        if echo 'int main() {}' | $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null -ljemalloc \
+        if echo 'int main() {}' | $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o -ljemalloc \
          2>/dev/null; then
            # This will enable some preprocessor identifiers in the Makefile
            JEMALLOC=1
@@ -451,7 +439,7 @@ EOF
    fi
    if ! test $JEMALLOC && ! test $ROCKSDB_DISABLE_TCMALLOC; then
        # jemalloc is not available. Let's try tcmalloc
-        if echo 'int main() {}' | $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null \
+        if echo 'int main() {}' | $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o \
          -ltcmalloc 2>/dev/null; then
            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -ltcmalloc"
            JAVA_LDFLAGS="$JAVA_LDFLAGS -ltcmalloc"
@@ -460,7 +448,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_MALLOC_USABLE_SIZE; then
        # Test whether malloc_usable_size is available
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <malloc.h>
          int main() {
            size_t res = malloc_usable_size(0);
@@ -475,7 +463,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_MEMKIND; then
        # Test whether memkind library is installed
-        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -lmemkind -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -lmemkind -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <memkind.h>
          int main() {
            memkind_malloc(MEMKIND_DAX_KMEM, 1024);
@@ -491,7 +479,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_PTHREAD_MUTEX_ADAPTIVE_NP; then
        # Test whether PTHREAD_MUTEX_ADAPTIVE_NP mutex type is available
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <pthread.h>
          int main() {
            int x = PTHREAD_MUTEX_ADAPTIVE_NP;
@@ -506,7 +494,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_BACKTRACE; then
        # Test whether backtrace is available
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <execinfo.h>
          int main() {
            void* frames[1];
@@ -518,7 +506,7 @@ EOF
            COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_BACKTRACE"
        else
            # Test whether execinfo library is installed
-            $CXX $PLATFORM_CXXFLAGS -lexecinfo -x c++ - -o /dev/null 2>/dev/null  <<EOF
+            $CXX $PLATFORM_CXXFLAGS -lexecinfo -x c++ - -o test.o 2>/dev/null  <<EOF
              #include <execinfo.h>
              int main() {
                void* frames[1];
@@ -535,7 +523,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_PG; then
        # Test if -pg is supported
-        $CXX $PLATFORM_CXXFLAGS -pg -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -pg -x c++ - -o test.o 2>/dev/null  <<EOF
          int main() {
            return 0;
          }
@@ -547,7 +535,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_SYNC_FILE_RANGE; then
        # Test whether sync_file_range is supported for compatibility with an old glibc
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <fcntl.h>
          int main() {
            int fd = open("/dev/null", 0);
@@ -561,7 +549,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_SCHED_GETCPU; then
        # Test whether sched_getcpu is supported
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <sched.h>
          int main() {
            int cpuid = sched_getcpu();
@@ -575,7 +563,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_AUXV_GETAUXVAL; then
        # Test whether getauxval is supported
-        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null  <<EOF
          #include <sys/auxv.h>
          int main() {
            uint64_t auxv = getauxval(AT_HWCAP);
@@ -589,7 +577,7 @@ EOF

    if ! test $ROCKSDB_DISABLE_ALIGNED_NEW; then
        # Test whether c++17 aligned-new is supported
-        $CXX $PLATFORM_CXXFLAGS -faligned-new -x c++ - -o /dev/null 2>/dev/null <<EOF
+        $CXX $PLATFORM_CXXFLAGS -faligned-new -x c++ - -o test.o 2>/dev/null <<EOF
            struct alignas(1024) t {int a;};
            int main() {}
 EOF
@@ -597,13 +585,23 @@ EOF
            PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS -faligned-new -DHAVE_ALIGNED_NEW"
        fi
    fi
+    if ! test $ROCKSDB_DISABLE_BENCHMARK; then
+        # Test whether google benchmark is available
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null -lbenchmark -lpthread 2>/dev/null  <<EOF
+          #include <benchmark/benchmark.h>
+          int main() {}
+EOF
+        if [ "$?" = 0 ]; then
+            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lbenchmark"
+        fi
+    fi
 fi

 # TODO(tec): Fix -Wshorten-64-to-32 errors on FreeBSD and enable the warning.
-# -Wshorten-64-to-32 breaks compilation on FreeBSD i386
-if ! [ "$TARGET_OS" = FreeBSD -a "$TARGET_ARCHITECTURE" = i386 ]; then
+# -Wshorten-64-to-32 breaks compilation on FreeBSD aarch64 and i386
+if ! { [ "$TARGET_OS" = FreeBSD ] && [ "$TARGET_ARCHITECTURE" = arm64 -o "$TARGET_ARCHITECTURE" = i386 ]; }; then
  # Test whether -Wshorten-64-to-32 is available
-  $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null -Wshorten-64-to-32 2>/dev/null  <<EOF
+  $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o -Wshorten-64-to-32 2>/dev/null  <<EOF
    int main() {}
 EOF
  if [ "$?" = 0 ]; then
@@ -611,34 +609,27 @@ EOF
  fi
 fi

-# shall we use HDFS?
-
-if test "$USE_HDFS"; then
-  if test -z "$JAVA_HOME"; then
-    echo "JAVA_HOME has to be set for HDFS usage." >&2
-    exit 1
-  fi
-  HDFS_CCFLAGS="$HDFS_CCFLAGS -I$JAVA_HOME/include -I$JAVA_HOME/include/linux -DUSE_HDFS -I$HADOOP_HOME/include"
-  HDFS_LDFLAGS="$HDFS_LDFLAGS -lhdfs -L$JAVA_HOME/jre/lib/amd64 -L$HADOOP_HOME/lib/native"
-  HDFS_LDFLAGS="$HDFS_LDFLAGS -L$JAVA_HOME/jre/lib/amd64/server -L$GLIBC_RUNTIME_PATH/lib"
-  HDFS_LDFLAGS="$HDFS_LDFLAGS -ldl -lverify -ljava -ljvm"
-  COMMON_FLAGS="$COMMON_FLAGS $HDFS_CCFLAGS"
-  PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS $HDFS_LDFLAGS"
-  JAVA_LDFLAGS="$JAVA_LDFLAGS $HDFS_LDFLAGS"
-fi
-
 if test "0$PORTABLE" -eq 0; then
  if test -n "`echo $TARGET_ARCHITECTURE | grep ^ppc64`"; then
    # Tune for this POWER processor, treating '+' models as base models
    POWER=`LD_SHOW_AUXV=1 /bin/true | grep AT_PLATFORM | grep -E -o power[0-9]+`
    COMMON_FLAGS="$COMMON_FLAGS -mcpu=$POWER -mtune=$POWER "
-  elif test -n "`echo $TARGET_ARCHITECTURE | grep ^s390x`"; then
-    COMMON_FLAGS="$COMMON_FLAGS -march=z10 "
  elif test -n "`echo $TARGET_ARCHITECTURE | grep -e^arm -e^aarch64`"; then
    # TODO: Handle this with approprite options.
    COMMON_FLAGS="$COMMON_FLAGS"
  elif test -n "`echo $TARGET_ARCHITECTURE | grep ^aarch64`"; then
    COMMON_FLAGS="$COMMON_FLAGS"
+  elif test -n "`echo $TARGET_ARCHITECTURE | grep ^s390x`"; then
+    if echo 'int main() {}' | $CXX $PLATFORM_CXXFLAGS -x c++ \
+      -march=native - -o /dev/null 2>/dev/null; then
+      COMMON_FLAGS="$COMMON_FLAGS -march=native "
+    else
+      COMMON_FLAGS="$COMMON_FLAGS -march=z196 "
+    fi
+    COMMON_FLAGS="$COMMON_FLAGS"
+  elif test -n "`echo $TARGET_ARCHITECTURE | grep ^riscv64`"; then
+    RISC_ISA=$(cat /proc/cpuinfo | grep isa | head -1 | cut --delimiter=: -f 2 | cut -b 2-)
+    COMMON_FLAGS="$COMMON_FLAGS -march=${RISC_ISA}"
  elif [ "$TARGET_OS" == "IOS" ]; then
    COMMON_FLAGS="$COMMON_FLAGS"
  elif [ "$TARGET_OS" == "AIX" ] || [ "$TARGET_OS" == "SunOS" ]; then
@@ -655,11 +646,21 @@ else
    TRY_SSE_ETC="1"
  fi

+  if test -n "`echo $TARGET_ARCHITECTURE | grep ^s390x`"; then
+    COMMON_FLAGS="$COMMON_FLAGS -march=z196 "
+  fi
+
+  if test -n "`echo $TARGET_ARCHITECTURE | grep ^riscv64`"; then
+    RISC_ISA=$(cat /proc/cpuinfo | grep isa | head -1 | cut --delimiter=: -f 2 | cut -b 2-)
+    COMMON_FLAGS="$COMMON_FLAGS -march=${RISC_ISA}"
+  fi
+
  if [[ "${PLATFORM}" == "OS_MACOSX" ]]; then
    # For portability compile for macOS 10.12 (2016) or newer
    COMMON_FLAGS="$COMMON_FLAGS -mmacosx-version-min=10.12"
    PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -mmacosx-version-min=10.12"
-    PLATFORM_SHARED_LDFLAGS="$PLATFORM_SHARED_LDFLAGS -mmacosx-version-min=10.12"
+    # -mmacosx-version-min must come first here.
+    PLATFORM_SHARED_LDFLAGS="-mmacosx-version-min=10.12 $PLATFORM_SHARED_LDFLAGS"
    PLATFORM_CMAKE_FLAGS="-DCMAKE_OSX_DEPLOYMENT_TARGET=10.12"
    JAVA_STATIC_DEPS_COMMON_FLAGS="-mmacosx-version-min=10.12"
    JAVA_STATIC_DEPS_LDFLAGS="$JAVA_STATIC_DEPS_COMMON_FLAGS"
@@ -706,7 +707,7 @@ if test "$TRY_SSE_ETC"; then
  TRY_LZCNT="-mlzcnt"
 fi

-$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_SSE42 -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_SSE42 -x c++ - -o test.o 2>/dev/null <<EOF
  #include <cstdint>
  #include <nmmintrin.h>
  int main() {
@@ -720,7 +721,7 @@ elif test "$USE_SSE"; then
  echo "warning: USE_SSE specified but compiler could not use SSE intrinsics, disabling" >&2
 fi

-$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_PCLMUL -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_PCLMUL -x c++ - -o test.o 2>/dev/null <<EOF
  #include <cstdint>
  #include <wmmintrin.h>
  int main() {
@@ -737,7 +738,7 @@ elif test "$USE_SSE"; then
  echo "warning: USE_SSE specified but compiler could not use PCLMUL intrinsics, disabling" >&2
 fi

-$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_AVX2 -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_AVX2 -x c++ - -o test.o 2>/dev/null <<EOF
  #include <cstdint>
  #include <immintrin.h>
  int main() {
@@ -752,7 +753,7 @@ elif test "$USE_SSE"; then
  echo "warning: USE_SSE specified but compiler could not use AVX2 intrinsics, disabling" >&2
 fi

-$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_BMI -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_BMI -x c++ - -o test.o 2>/dev/null <<EOF
  #include <cstdint>
  #include <immintrin.h>
  int main(int argc, char *argv[]) {
@@ -766,7 +767,7 @@ elif test "$USE_SSE"; then
  echo "warning: USE_SSE specified but compiler could not use BMI intrinsics, disabling" >&2
 fi

-$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_LZCNT -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS $TRY_LZCNT -x c++ - -o test.o 2>/dev/null <<EOF
  #include <cstdint>
  #include <immintrin.h>
  int main(int argc, char *argv[]) {
@@ -780,7 +781,7 @@ elif test "$USE_SSE"; then
  echo "warning: USE_SSE specified but compiler could not use LZCNT intrinsics, disabling" >&2
 fi

-$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o test.o 2>/dev/null <<EOF
  #include <cstdint>
  int main() {
    uint64_t a = 0xffffFFFFffffFFFF;
@@ -793,31 +794,15 @@ if [ "$?" = 0 ]; then
  COMMON_FLAGS="$COMMON_FLAGS -DHAVE_UINT128_EXTENSION"
 fi

-# iOS doesn't support thread-local storage, but this check would erroneously
-# succeed because the cross-compiler flags are added by the Makefile, not this
-# script.
-if [ "$PLATFORM" != IOS ]; then
-  $CXX $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
-  #if defined(_MSC_VER) && !defined(__thread)
-  #define __thread __declspec(thread)
-  #endif
-  int main() {
-    static __thread int tls;
-    (void)tls;
-  }
-EOF
-  if [ "$?" = 0 ]; then
-    COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SUPPORT_THREAD_LOCAL"
-  fi
-fi
-
+# thread_local is part of C++11 and later (TODO: clean up this define)
+COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SUPPORT_THREAD_LOCAL"

 if [ "$FBCODE_BUILD" != "true" -a "$PLATFORM" = OS_LINUX ]; then
  $CXX $COMMON_FLAGS $PLATFORM_SHARED_CFLAGS -x c++ -c - -o test_dl.o 2>/dev/null <<EOF
  void dummy_func() {}
 EOF
  if [ "$?" = 0 ]; then
-    $CXX $COMMON_FLAGS $PLATFORM_SHARED_LDFLAGS test_dl.o -o /dev/null 2>/dev/null
+    $CXX $COMMON_FLAGS $PLATFORM_SHARED_LDFLAGS test_dl.o -o test.o 2>/dev/null
    if [ "$?" = 0 ]; then
      EXEC_LDFLAGS+="-ldl"
      rm -f test_dl.o
@@ -825,6 +810,20 @@ EOF
  fi
 fi

+# check for F_FULLFSYNC
+$CXX $PLATFORM_CXXFALGS -x c++ - -o test.o 2>/dev/null  <<EOF
+  #include <fcntl.h>
+  int main() {
+    fcntl(0, F_FULLFSYNC);
+    return 0;
+  }
+EOF
+if [ "$?" = 0 ]; then
+  COMMON_FLAGS="$COMMON_FLAGS -DHAVE_FULLFSYNC"
+fi
+
+rm -f test.o test_dl.o
+
 PLATFORM_CCFLAGS="$PLATFORM_CCFLAGS $COMMON_FLAGS"
 PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS $COMMON_FLAGS"

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+#
+# Check for some simple mistakes that should prevent commit or push
+
+BAD=""
+
+git grep 'namespace rocksdb' -- '*.[ch]*'
+if [ "$?" != "1" ]; then
+  echo "^^^^^ Do not hardcode namespace rocksdb. Use ROCKSDB_NAMESPACE"
+  BAD=1
+fi
+
+git grep -i 'nocommit' -- ':!build_tools/check-sources.sh'
+if [ "$?" != "1" ]; then
+  echo "^^^^^ Code was not intended to be committed"
+  BAD=1
+fi
+
+git grep '<rocksdb/' -- ':!build_tools/check-sources.sh'
+if [ "$?" != "1" ]; then
+  echo '^^^^^ Use double-quotes as in #include "rocksdb/something.h"'
+  BAD=1
+fi
+
+git grep 'using namespace' -- ':!build_tools' ':!docs' \
+    ':!third-party/folly/folly/lang/Align.h' \
+    ':!third-party/gtest-1.8.1/fused-src/gtest/gtest.h'
+if [ "$?" != "1" ]; then
+  echo '^^^^ Do not use "using namespace"'
+  BAD=1
+fi
+
+if [ "$BAD" ]; then
+  exit 1
+fi
@@ -1,19 +0,0 @@
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-GCC_BASE=/mnt/gvfs/third-party2/gcc/7331085db891a2ef4a88a48a751d834e8d68f4cb/5.x/centos7-native/c447969
-CLANG_BASE=/mnt/gvfs/third-party2/llvm-fb/1bd23f9917738974ad0ff305aa23eb5f93f18305/9.0.0/centos7-native/c9f9104
-LIBGCC_BASE=/mnt/gvfs/third-party2/libgcc/6ace84e956873d53638c738b6f65f3f469cca74c/5.x/gcc-5-glibc-2.23/339d858
-GLIBC_BASE=/mnt/gvfs/third-party2/glibc/192b0f42d63dcf6210d6ceae387b49af049e6e0c/2.23/gcc-5-glibc-2.23/ca1d1c0
-SNAPPY_BASE=/mnt/gvfs/third-party2/snappy/7f9bdaada18f59bc27ec2b0871eb8a6144343aef/1.1.3/gcc-5-glibc-2.23/9bc6787
-ZLIB_BASE=/mnt/gvfs/third-party2/zlib/2d9f0b9a4274cc21f61272a9e89bdb859bce8f1f/1.2.8/gcc-5-glibc-2.23/9bc6787
-BZIP2_BASE=/mnt/gvfs/third-party2/bzip2/dc49a21c5fceec6456a7a28a94dcd16690af1337/1.0.6/gcc-5-glibc-2.23/9bc6787
-LZ4_BASE=/mnt/gvfs/third-party2/lz4/0f607f8fc442ea7d6b876931b1898bb573d5e5da/1.9.1/gcc-5-glibc-2.23/9bc6787
-ZSTD_BASE=/mnt/gvfs/third-party2/zstd/ca22bc441a4eb709e9e0b1f9fec9750fed7b31c5/1.4.x/gcc-5-glibc-2.23/03859b5
-GFLAGS_BASE=/mnt/gvfs/third-party2/gflags/0b9929d2588991c65a57168bf88aff2db87c5d48/2.2.0/gcc-5-glibc-2.23/9bc6787
-JEMALLOC_BASE=/mnt/gvfs/third-party2/jemalloc/c26f08f47ac35fc31da2633b7da92d6b863246eb/master/gcc-5-glibc-2.23/0c8f76d
-NUMA_BASE=/mnt/gvfs/third-party2/numa/3f3fb57a5ccc5fd21c66416c0b83e0aa76a05376/2.0.11/gcc-5-glibc-2.23/9bc6787
-LIBUNWIND_BASE=/mnt/gvfs/third-party2/libunwind/40c73d874898b386a71847f1b99115d93822d11f/1.4/gcc-5-glibc-2.23/b443de1
-TBB_BASE=/mnt/gvfs/third-party2/tbb/4ce8e8dba77cdbd81b75d6f0c32fd7a1b76a11ec/2018_U5/gcc-5-glibc-2.23/9bc6787
-KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/fb251ecd2f5ae16f8671f7014c246e52a748fe0b/4.0.9-36_fbk5_2933_gd092e3f/gcc-5-glibc-2.23/da39a3e
-BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/2e3cb7d119b3cea5f1e738cc13a1ac69f49eb875/2.29.1/centos7-native/da39a3e
-VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/d42d152a15636529b0861ec493927200ebebca8e/3.15.0/gcc-5-glibc-2.23/9bc6787
-LUA_BASE=/mnt/gvfs/third-party2/lua/f0cd714433206d5139df61659eb7b28b1dea6683/5.2.3/gcc-5-glibc-2.23/65372bd
@@ -1,20 +0,0 @@
-# shellcheck disable=SC2148
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-GCC_BASE=/mnt/gvfs/third-party2/gcc/cf7d14c625ce30bae1a4661c2319c5a283e4dd22/4.8.1/centos6-native/cc6c9dc
-CLANG_BASE=/mnt/gvfs/third-party2/llvm-fb/8598c375b0e94e1448182eb3df034704144a838d/stable/centos6-native/3f16ddd
-LIBGCC_BASE=/mnt/gvfs/third-party2/libgcc/d6e0a7da6faba45f5e5b1638f9edd7afc2f34e7d/4.8.1/gcc-4.8.1-glibc-2.17/8aac7fc
-GLIBC_BASE=/mnt/gvfs/third-party2/glibc/d282e6e8f3d20f4e40a516834847bdc038e07973/2.17/gcc-4.8.1-glibc-2.17/99df8fc
-SNAPPY_BASE=/mnt/gvfs/third-party2/snappy/8c38a4c1e52b4c2cc8a9cdc31b9c947ed7dbfcb4/1.1.3/gcc-4.8.1-glibc-2.17/c3f970a
-ZLIB_BASE=/mnt/gvfs/third-party2/zlib/0882df3713c7a84f15abe368dc004581f20b39d7/1.2.8/gcc-4.8.1-glibc-2.17/c3f970a
-BZIP2_BASE=/mnt/gvfs/third-party2/bzip2/740325875f6729f42d28deaa2147b0854f3a347e/1.0.6/gcc-4.8.1-glibc-2.17/c3f970a
-LZ4_BASE=/mnt/gvfs/third-party2/lz4/0e790b441e2d9acd68d51e1d2e028f88c6a79ddf/r131/gcc-4.8.1-glibc-2.17/c3f970a
-ZSTD_BASE=/mnt/gvfs/third-party2/zstd/9455f75ff7f4831dc9fda02a6a0f8c68922fad8f/1.0.0/gcc-4.8.1-glibc-2.17/c3f970a
-GFLAGS_BASE=/mnt/gvfs/third-party2/gflags/f001a51b2854957676d07306ef3abf67186b5c8b/2.1.1/gcc-4.8.1-glibc-2.17/c3f970a
-JEMALLOC_BASE=/mnt/gvfs/third-party2/jemalloc/fc8a13ca1fffa4d0765c716c5a0b49f0c107518f/master/gcc-4.8.1-glibc-2.17/8d31e51
-NUMA_BASE=/mnt/gvfs/third-party2/numa/17c514c4d102a25ca15f4558be564eeed76f4b6a/2.0.8/gcc-4.8.1-glibc-2.17/c3f970a
-LIBUNWIND_BASE=/mnt/gvfs/third-party2/libunwind/ad576de2a1ea560c4d3434304f0fc4e079bede42/trunk/gcc-4.8.1-glibc-2.17/675d945
-TBB_BASE=/mnt/gvfs/third-party2/tbb/9d9a554877d0c5bef330fe818ab7178806dd316a/4.0_update2/gcc-4.8.1-glibc-2.17/c3f970a
-KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/7c111ff27e0c466235163f00f280a9d617c3d2ec/4.0.9-36_fbk5_2933_gd092e3f/gcc-4.8.1-glibc-2.17/da39a3e
-BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/b7fd454c4b10c6a81015d4524ed06cdeab558490/2.26/centos6-native/da39a3e
-VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/d7f4d4d86674a57668e3a96f76f0e17dd0eb8765/3.8.1/gcc-4.8.1-glibc-2.17/c3f970a
-LUA_BASE=/mnt/gvfs/third-party2/lua/61e4abf5813bbc39bc4f548757ccfcadde175a48/5.2.3/centos6-native/730f94e
@@ -1,20 +0,0 @@
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-GCC_BASE=/mnt/gvfs/third-party2/gcc/7331085db891a2ef4a88a48a751d834e8d68f4cb/7.x/centos7-native/b2ef2b6
-CLANG_BASE=/mnt/gvfs/third-party2/llvm-fb/963d9aeda70cc4779885b1277484fe7544a04e3e/9.0.0/platform007/9e92d53/
-LIBGCC_BASE=/mnt/gvfs/third-party2/libgcc/6ace84e956873d53638c738b6f65f3f469cca74c/7.x/platform007/5620abc
-GLIBC_BASE=/mnt/gvfs/third-party2/glibc/192b0f42d63dcf6210d6ceae387b49af049e6e0c/2.26/platform007/f259413
-SNAPPY_BASE=/mnt/gvfs/third-party2/snappy/7f9bdaada18f59bc27ec2b0871eb8a6144343aef/1.1.3/platform007/ca4da3d
-ZLIB_BASE=/mnt/gvfs/third-party2/zlib/2d9f0b9a4274cc21f61272a9e89bdb859bce8f1f/1.2.8/platform007/ca4da3d
-BZIP2_BASE=/mnt/gvfs/third-party2/bzip2/dc49a21c5fceec6456a7a28a94dcd16690af1337/1.0.6/platform007/ca4da3d
-LZ4_BASE=/mnt/gvfs/third-party2/lz4/0f607f8fc442ea7d6b876931b1898bb573d5e5da/1.9.1/platform007/ca4da3d
-ZSTD_BASE=/mnt/gvfs/third-party2/zstd/ca22bc441a4eb709e9e0b1f9fec9750fed7b31c5/1.4.x/platform007/15a3614
-GFLAGS_BASE=/mnt/gvfs/third-party2/gflags/0b9929d2588991c65a57168bf88aff2db87c5d48/2.2.0/platform007/ca4da3d
-JEMALLOC_BASE=/mnt/gvfs/third-party2/jemalloc/c26f08f47ac35fc31da2633b7da92d6b863246eb/master/platform007/c26c002
-NUMA_BASE=/mnt/gvfs/third-party2/numa/3f3fb57a5ccc5fd21c66416c0b83e0aa76a05376/2.0.11/platform007/ca4da3d
-LIBUNWIND_BASE=/mnt/gvfs/third-party2/libunwind/40c73d874898b386a71847f1b99115d93822d11f/1.4/platform007/6f3e0a9
-TBB_BASE=/mnt/gvfs/third-party2/tbb/4ce8e8dba77cdbd81b75d6f0c32fd7a1b76a11ec/2018_U5/platform007/ca4da3d
-LIBURING_BASE=/mnt/gvfs/third-party2/liburing/79427253fd0d42677255aacfe6d13bfe63f752eb/20190828/platform007/ca4da3d
-KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/fb251ecd2f5ae16f8671f7014c246e52a748fe0b/fb/platform007/da39a3e
-BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/ab9f09bba370e7066cafd4eb59752db93f2e8312/2.29.1/platform007/15a3614
-VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/d42d152a15636529b0861ec493927200ebebca8e/3.15.0/platform007/ca4da3d
-LUA_BASE=/mnt/gvfs/third-party2/lua/f0cd714433206d5139df61659eb7b28b1dea6683/5.3.4/platform007/5007832
@@ -18,3 +18,4 @@ KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/32b8a2407b634df3f8f948
 BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/08634589372fa5f237bfd374e8c644a8364e78c1/2.32/platform009/ba86d1f/
 VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/6ae525939ad02e5e676855082fbbc7828dbafeac/3.15.0/platform009/7f3b187
 LUA_BASE=/mnt/gvfs/third-party2/lua/162efd9561a3d21f6869f4814011e9cf1b3ff4dc/5.3.4/platform009/a6271c4
+BENCHMARK_BASE=/mnt/gvfs/third-party2/benchmark/30bf49ad6414325e17f3425b0edcb64239427ae3/1.6.1/platform009/7f3b187
@@ -1,120 +0,0 @@
-#!/bin/sh
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-#
-# Set environment variables so that we can compile rocksdb using
-# fbcode settings.  It uses the latest g++ compiler and also
-# uses jemalloc
-
-BASEDIR=`dirname $BASH_SOURCE`
-source "$BASEDIR/dependencies_4.8.1.sh"
-
-# location of libgcc
-LIBGCC_INCLUDE="$LIBGCC_BASE/include"
-LIBGCC_LIBS=" -L $LIBGCC_BASE/lib"
-
-# location of glibc
-GLIBC_INCLUDE="$GLIBC_BASE/include"
-GLIBC_LIBS=" -L $GLIBC_BASE/lib"
-
-# location of snappy headers and libraries
-SNAPPY_INCLUDE=" -I $SNAPPY_BASE/include"
-SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy.a"
-
-# location of zlib headers and libraries
-ZLIB_INCLUDE=" -I $ZLIB_BASE/include"
-ZLIB_LIBS=" $ZLIB_BASE/lib/libz.a"
-
-# location of bzip headers and libraries
-BZIP2_INCLUDE=" -I $BZIP2_BASE/include/"
-BZIP2_LIBS=" $BZIP2_BASE/lib/libbz2.a"
-
-LZ4_INCLUDE=" -I $LZ4_BASE/include"
-LZ4_LIBS=" $LZ4_BASE/lib/liblz4.a"
-
-ZSTD_INCLUDE=" -I $ZSTD_BASE/include"
-ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd.a"
-
-# location of gflags headers and libraries
-GFLAGS_INCLUDE=" -I $GFLAGS_BASE/include/"
-GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags.a"
-
-# location of jemalloc
-JEMALLOC_INCLUDE=" -I $JEMALLOC_BASE/include"
-JEMALLOC_LIB="$JEMALLOC_BASE/lib/libjemalloc.a"
-
-# location of numa
-NUMA_INCLUDE=" -I $NUMA_BASE/include/"
-NUMA_LIB=" $NUMA_BASE/lib/libnuma.a"
-
-# location of libunwind
-LIBUNWIND="$LIBUNWIND_BASE/lib/libunwind.a"
-
-# location of tbb
-TBB_INCLUDE=" -isystem $TBB_BASE/include/"
-TBB_LIBS="$TBB_BASE/lib/libtbb.a"
-
-test "$USE_SSE" || USE_SSE=1
-export USE_SSE
-test "$PORTABLE" || PORTABLE=1
-export PORTABLE
-
-BINUTILS="$BINUTILS_BASE/bin"
-AR="$BINUTILS/ar"
-
-DEPS_INCLUDE="$SNAPPY_INCLUDE $ZLIB_INCLUDE $BZIP2_INCLUDE $LZ4_INCLUDE $ZSTD_INCLUDE $GFLAGS_INCLUDE $NUMA_INCLUDE $TBB_INCLUDE"
-
-STDLIBS="-L $GCC_BASE/lib64"
-
-if [ -z "$USE_CLANG" ]; then
-  # gcc
-  CC="$GCC_BASE/bin/gcc"
-  CXX="$GCC_BASE/bin/g++"
-  CXX="$GCC_BASE/bin/gcc-ar"
-
-  CFLAGS="-B$BINUTILS/gold -m64 -mtune=generic"
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  JEMALLOC=1
-else
-  # clang
-  CLANG_BIN="$CLANG_BASE/bin"
-  CLANG_LIB="$CLANG_BASE/lib"
-  CLANG_INCLUDE="$CLANG_LIB/clang/*/include"
-  CC="$CLANG_BIN/clang"
-  CXX="$CLANG_BIN/clang++"
-  AR="$CLANG_BIN/llvm-ar"
-
-  KERNEL_HEADERS_INCLUDE="$KERNEL_HEADERS_BASE/include/"
-
-  CFLAGS="-B$BINUTILS/gold -nostdinc -nostdlib"
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/4.8.1 "
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/4.8.1/x86_64-facebook-linux "
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $CLANG_INCLUDE"
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE/linux "
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE "
-  CXXFLAGS="-nostdinc++"
-fi
-
-CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42"
-CFLAGS+=" -DSNAPPY -DGFLAGS=google -DZLIB -DBZIP2 -DLZ4 -DZSTD -DNUMA -DTBB"
-CXXFLAGS+=" $CFLAGS"
-
-EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP2_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS"
-EXEC_LDFLAGS+=" -Wl,--dynamic-linker,/usr/local/fbcode/gcc-4.8.1-glibc-2.17/lib/ld.so"
-EXEC_LDFLAGS+=" $LIBUNWIND"
-EXEC_LDFLAGS+=" -Wl,-rpath=/usr/local/fbcode/gcc-4.8.1-glibc-2.17/lib"
-# required by libtbb
-EXEC_LDFLAGS+=" -ldl"
-
-PLATFORM_LDFLAGS="$LIBGCC_LIBS $GLIBC_LIBS $STDLIBS -lgcc -lstdc++"
-
-EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP2_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS"
-
-VALGRIND_VER="$VALGRIND_BASE/bin/"
-
-LUA_PATH="$LUA_BASE"
-
-export CC CXX AR CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE LUA_PATH
@@ -1,172 +0,0 @@
-#!/bin/sh
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-#
-# Set environment variables so that we can compile rocksdb using
-# fbcode settings.  It uses the latest g++ and clang compilers and also
-# uses jemalloc
-# Environment variables that change the behavior of this script:
-# PIC_BUILD -- if true, it will only take pic versions of libraries from fbcode. libraries that don't have pic variant will not be included
-
-
-BASEDIR=`dirname $BASH_SOURCE`
-source "$BASEDIR/dependencies_platform007.sh"
-
-CFLAGS=""
-
-# libgcc
-LIBGCC_INCLUDE="$LIBGCC_BASE/include/c++/7.3.0"
-LIBGCC_LIBS=" -L $LIBGCC_BASE/lib"
-
-# glibc
-GLIBC_INCLUDE="$GLIBC_BASE/include"
-GLIBC_LIBS=" -L $GLIBC_BASE/lib"
-
-# snappy
-SNAPPY_INCLUDE=" -I $SNAPPY_BASE/include/"
-if test -z $PIC_BUILD; then
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy.a"
-else
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy_pic.a"
-fi
-CFLAGS+=" -DSNAPPY"
-
-if test -z $PIC_BUILD; then
-  # location of zlib headers and libraries
-  ZLIB_INCLUDE=" -I $ZLIB_BASE/include/"
-  ZLIB_LIBS=" $ZLIB_BASE/lib/libz.a"
-  CFLAGS+=" -DZLIB"
-
-  # location of bzip headers and libraries
-  BZIP_INCLUDE=" -I $BZIP2_BASE/include/"
-  BZIP_LIBS=" $BZIP2_BASE/lib/libbz2.a"
-  CFLAGS+=" -DBZIP2"
-
-  LZ4_INCLUDE=" -I $LZ4_BASE/include/"
-  LZ4_LIBS=" $LZ4_BASE/lib/liblz4.a"
-  CFLAGS+=" -DLZ4"
-fi
-
-ZSTD_INCLUDE=" -I $ZSTD_BASE/include/"
-if test -z $PIC_BUILD; then
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd.a"
-else
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd_pic.a"
-fi
-CFLAGS+=" -DZSTD"
-
-# location of gflags headers and libraries
-GFLAGS_INCLUDE=" -I $GFLAGS_BASE/include/"
-if test -z $PIC_BUILD; then
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags.a"
-else
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags_pic.a"
-fi
-CFLAGS+=" -DGFLAGS=gflags"
-
-# location of jemalloc
-JEMALLOC_INCLUDE=" -I $JEMALLOC_BASE/include/"
-JEMALLOC_LIB=" $JEMALLOC_BASE/lib/libjemalloc.a"
-
-if test -z $PIC_BUILD; then
-  # location of numa
-  NUMA_INCLUDE=" -I $NUMA_BASE/include/"
-  NUMA_LIB=" $NUMA_BASE/lib/libnuma.a"
-  CFLAGS+=" -DNUMA"
-
-  # location of libunwind
-  LIBUNWIND="$LIBUNWIND_BASE/lib/libunwind.a"
-fi
-
-# location of TBB
-TBB_INCLUDE=" -isystem $TBB_BASE/include/"
-if test -z $PIC_BUILD; then
-  TBB_LIBS="$TBB_BASE/lib/libtbb.a"
-else
-  TBB_LIBS="$TBB_BASE/lib/libtbb_pic.a"
-fi
-CFLAGS+=" -DTBB"
-
-# location of LIBURING
-LIBURING_INCLUDE=" -isystem $LIBURING_BASE/include/"
-if test -z $PIC_BUILD; then
-  LIBURING_LIBS="$LIBURING_BASE/lib/liburing.a"
-else
-  LIBURING_LIBS="$LIBURING_BASE/lib/liburing_pic.a"
-fi
-CFLAGS+=" -DLIBURING"
-
-test "$USE_SSE" || USE_SSE=1
-export USE_SSE
-test "$PORTABLE" || PORTABLE=1
-export PORTABLE
-
-BINUTILS="$BINUTILS_BASE/bin"
-AR="$BINUTILS/ar"
-
-DEPS_INCLUDE="$SNAPPY_INCLUDE $ZLIB_INCLUDE $BZIP_INCLUDE $LZ4_INCLUDE $ZSTD_INCLUDE $GFLAGS_INCLUDE $NUMA_INCLUDE $TBB_INCLUDE $LIBURING_INCLUDE"
-
-STDLIBS="-L $GCC_BASE/lib64"
-
-CLANG_BIN="$CLANG_BASE/bin"
-CLANG_LIB="$CLANG_BASE/lib"
-CLANG_SRC="$CLANG_BASE/../../src"
-
-CLANG_ANALYZER="$CLANG_BIN/clang++"
-CLANG_SCAN_BUILD="$CLANG_SRC/llvm/tools/clang/tools/scan-build/bin/scan-build"
-
-if [ -z "$USE_CLANG" ]; then
-  # gcc
-  CC="$GCC_BASE/bin/gcc"
-  CXX="$GCC_BASE/bin/g++"
-  AR="$GCC_BASE/bin/gcc-ar"
-
-  CFLAGS+=" -B$BINUTILS/gold"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  JEMALLOC=1
-else
-  # clang
-  CLANG_INCLUDE="$CLANG_LIB/clang/stable/include"
-  CC="$CLANG_BIN/clang"
-  CXX="$CLANG_BIN/clang++"
-  AR="$CLANG_BIN/llvm-ar"
-
-  KERNEL_HEADERS_INCLUDE="$KERNEL_HEADERS_BASE/include"
-
-  CFLAGS+=" -B$BINUTILS/gold -nostdinc -nostdlib"
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/7.x "
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/7.x/x86_64-facebook-linux "
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $CLANG_INCLUDE"
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE/linux "
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE "
-  CFLAGS+=" -Wno-expansion-to-defined "
-  CXXFLAGS="-nostdinc++"
-fi
-
-CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42 -DROCKSDB_IOURING_PRESENT"
-CXXFLAGS+=" $CFLAGS"
-
-EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS $LIBURING_LIBS"
-EXEC_LDFLAGS+=" -B$BINUTILS/gold"
-EXEC_LDFLAGS+=" -Wl,--dynamic-linker,/usr/local/fbcode/platform007/lib/ld.so"
-EXEC_LDFLAGS+=" $LIBUNWIND"
-EXEC_LDFLAGS+=" -Wl,-rpath=/usr/local/fbcode/platform007/lib"
-# required by libtbb
-EXEC_LDFLAGS+=" -ldl"
-
-PLATFORM_LDFLAGS="$LIBGCC_LIBS $GLIBC_LIBS $STDLIBS -lgcc -lstdc++"
-
-EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $TBB_LIBS $LIBURING_LIBS"
-
-VALGRIND_VER="$VALGRIND_BASE/bin/"
-
-# lua not supported because it's on track for deprecation, I think
-LUA_PATH=
-LUA_LIB=
-
-USE_FOLLY_DISTRIBUTED_MUTEX=1
-
-export CC CXX AR CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE CLANG_ANALYZER CLANG_SCAN_BUILD LUA_PATH LUA_LIB
@@ -21,78 +21,63 @@ LIBGCC_LIBS=" -L $LIBGCC_BASE/lib"
 GLIBC_INCLUDE="$GLIBC_BASE/include"
 GLIBC_LIBS=" -L $GLIBC_BASE/lib"

+if test -z $PIC_BUILD; then
+  MAYBE_PIC=
+else
+  MAYBE_PIC=_pic
+fi
+
 # snappy
 SNAPPY_INCLUDE=" -I $SNAPPY_BASE/include/"
-if test -z $PIC_BUILD; then
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy.a"
-else
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy_pic.a"
-fi
+SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy${MAYBE_PIC}.a"
 CFLAGS+=" -DSNAPPY"

-if test -z $PIC_BUILD; then
-  # location of zlib headers and libraries
-  ZLIB_INCLUDE=" -I $ZLIB_BASE/include/"
-  ZLIB_LIBS=" $ZLIB_BASE/lib/libz.a"
-  CFLAGS+=" -DZLIB"
+# location of zlib headers and libraries
+ZLIB_INCLUDE=" -I $ZLIB_BASE/include/"
+ZLIB_LIBS=" $ZLIB_BASE/lib/libz${MAYBE_PIC}.a"
+CFLAGS+=" -DZLIB"

-  # location of bzip headers and libraries
-  BZIP_INCLUDE=" -I $BZIP2_BASE/include/"
-  BZIP_LIBS=" $BZIP2_BASE/lib/libbz2.a"
-  CFLAGS+=" -DBZIP2"
+# location of bzip headers and libraries
+BZIP_INCLUDE=" -I $BZIP2_BASE/include/"
+BZIP_LIBS=" $BZIP2_BASE/lib/libbz2${MAYBE_PIC}.a"
+CFLAGS+=" -DBZIP2"

-  LZ4_INCLUDE=" -I $LZ4_BASE/include/"
-  LZ4_LIBS=" $LZ4_BASE/lib/liblz4.a"
-  CFLAGS+=" -DLZ4"
-fi
+LZ4_INCLUDE=" -I $LZ4_BASE/include/"
+LZ4_LIBS=" $LZ4_BASE/lib/liblz4${MAYBE_PIC}.a"
+CFLAGS+=" -DLZ4"

 ZSTD_INCLUDE=" -I $ZSTD_BASE/include/"
-if test -z $PIC_BUILD; then
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd.a"
-else
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd_pic.a"
-fi
+ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd${MAYBE_PIC}.a"
 CFLAGS+=" -DZSTD"

 # location of gflags headers and libraries
 GFLAGS_INCLUDE=" -I $GFLAGS_BASE/include/"
-if test -z $PIC_BUILD; then
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags.a"
-else
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags_pic.a"
-fi
+GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags${MAYBE_PIC}.a"
 CFLAGS+=" -DGFLAGS=gflags"

+BENCHMARK_INCLUDE=" -I $BENCHMARK_BASE/include/"
+BENCHMARK_LIBS=" $BENCHMARK_BASE/lib/libbenchmark${MAYBE_PIC}.a"
+
 # location of jemalloc
 JEMALLOC_INCLUDE=" -I $JEMALLOC_BASE/include/"
-JEMALLOC_LIB=" $JEMALLOC_BASE/lib/libjemalloc.a"
+JEMALLOC_LIB=" $JEMALLOC_BASE/lib/libjemalloc${MAYBE_PIC}.a"

-if test -z $PIC_BUILD; then
-  # location of numa
-  NUMA_INCLUDE=" -I $NUMA_BASE/include/"
-  NUMA_LIB=" $NUMA_BASE/lib/libnuma.a"
-  CFLAGS+=" -DNUMA"
+# location of numa
+NUMA_INCLUDE=" -I $NUMA_BASE/include/"
+NUMA_LIB=" $NUMA_BASE/lib/libnuma${MAYBE_PIC}.a"
+CFLAGS+=" -DNUMA"

-  # location of libunwind
-  LIBUNWIND="$LIBUNWIND_BASE/lib/libunwind.a"
-fi
+# location of libunwind
+LIBUNWIND="$LIBUNWIND_BASE/lib/libunwind${MAYBE_PIC}.a"

 # location of TBB
 TBB_INCLUDE=" -isystem $TBB_BASE/include/"
-if test -z $PIC_BUILD; then
-  TBB_LIBS="$TBB_BASE/lib/libtbb.a"
-else
-  TBB_LIBS="$TBB_BASE/lib/libtbb_pic.a"
-fi
+TBB_LIBS="$TBB_BASE/lib/libtbb${MAYBE_PIC}.a"
 CFLAGS+=" -DTBB"

 # location of LIBURING
 LIBURING_INCLUDE=" -isystem $LIBURING_BASE/include/"
-if test -z $PIC_BUILD; then
-  LIBURING_LIBS="$LIBURING_BASE/lib/liburing.a"
-else
-  LIBURING_LIBS="$LIBURING_BASE/lib/liburing_pic.a"
-fi
+LIBURING_LIBS="$LIBURING_BASE/lib/liburing${MAYBE_PIC}.a"
 CFLAGS+=" -DLIBURING"

 test "$USE_SSE" || USE_SSE=1
@@ -102,8 +87,9 @@ export PORTABLE

 BINUTILS="$BINUTILS_BASE/bin"
 AR="$BINUTILS/ar"
+AS="$BINUTILS/as"

-DEPS_INCLUDE="$SNAPPY_INCLUDE $ZLIB_INCLUDE $BZIP_INCLUDE $LZ4_INCLUDE $ZSTD_INCLUDE $GFLAGS_INCLUDE $NUMA_INCLUDE $TBB_INCLUDE $LIBURING_INCLUDE"
+DEPS_INCLUDE="$SNAPPY_INCLUDE $ZLIB_INCLUDE $BZIP_INCLUDE $LZ4_INCLUDE $ZSTD_INCLUDE $GFLAGS_INCLUDE $NUMA_INCLUDE $TBB_INCLUDE $LIBURING_INCLUDE $BENCHMARK_INCLUDE"

 STDLIBS="-L $GCC_BASE/lib64"

@@ -120,7 +106,7 @@ if [ -z "$USE_CLANG" ]; then
  CXX="$GCC_BASE/bin/g++"
  AR="$GCC_BASE/bin/gcc-ar"

-  CFLAGS+=" -B$BINUTILS/gold"
+  CFLAGS+=" -B$BINUTILS"
  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
  CFLAGS+=" -isystem $GLIBC_INCLUDE"
  JEMALLOC=1
@@ -133,7 +119,7 @@ else

  KERNEL_HEADERS_INCLUDE="$KERNEL_HEADERS_BASE/include"

-  CFLAGS+=" -B$BINUTILS/gold -nostdinc -nostdlib"
+  CFLAGS+=" -B$BINUTILS -nostdinc -nostdlib"
  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/9.x "
  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/9.x/x86_64-facebook-linux "
  CFLAGS+=" -isystem $GLIBC_INCLUDE"
@@ -149,17 +135,18 @@ CFLAGS+=" $DEPS_INCLUDE"
 CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42 -DROCKSDB_IOURING_PRESENT"
 CXXFLAGS+=" $CFLAGS"

-EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS $LIBURING_LIBS"
-EXEC_LDFLAGS+=" -B$BINUTILS/gold"
+EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS $LIBURING_LIBS $BENCHMARK_LIBS"
 EXEC_LDFLAGS+=" -Wl,--dynamic-linker,/usr/local/fbcode/platform009/lib/ld.so"
 EXEC_LDFLAGS+=" $LIBUNWIND"
 EXEC_LDFLAGS+=" -Wl,-rpath=/usr/local/fbcode/platform009/lib"
+EXEC_LDFLAGS+=" -Wl,-rpath=$GCC_BASE/lib64"
 # required by libtbb
 EXEC_LDFLAGS+=" -ldl"

 PLATFORM_LDFLAGS="$LIBGCC_LIBS $GLIBC_LIBS $STDLIBS -lgcc -lstdc++"
+PLATFORM_LDFLAGS+=" -B$BINUTILS"

-EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $TBB_LIBS $LIBURING_LIBS"
+EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $TBB_LIBS $LIBURING_LIBS $BENCHMARK_LIBS"

 VALGRIND_VER="$VALGRIND_BASE/bin/"

@@ -167,6 +154,4 @@ VALGRIND_VER="$VALGRIND_BASE/bin/"
 LUA_PATH=
 LUA_LIB=

-USE_FOLLY_DISTRIBUTED_MUTEX=1
-
-export CC CXX AR CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE CLANG_ANALYZER CLANG_SCAN_BUILD LUA_PATH LUA_LIB
+export CC CXX AR AS CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE CLANG_ANALYZER CLANG_SCAN_BUILD LUA_PATH LUA_LIB
@@ -38,7 +38,9 @@ if [ "$CLANG_FORMAT_DIFF" ]; then
  fi
 else
  # First try directly executing the possibilities
-  if clang-format-diff.py --help &> /dev/null < /dev/null; then
+  if clang-format-diff --help &> /dev/null < /dev/null; then
+    CLANG_FORMAT_DIFF=clang-format-diff
+  elif clang-format-diff.py --help &> /dev/null < /dev/null; then
    CLANG_FORMAT_DIFF=clang-format-diff.py
  elif $REPO_ROOT/clang-format-diff.py --help &> /dev/null < /dev/null; then
    CLANG_FORMAT_DIFF=$REPO_ROOT/clang-format-diff.py
@@ -120,16 +122,16 @@ uncommitted_code=`git diff HEAD`

 # If there's no uncommitted changes, we assume user are doing post-commit
 # format check, in which case we'll try to check the modified lines vs. the
-# facebook/rocksdb.git master branch. Otherwise, we'll check format of the
+# facebook/rocksdb.git main branch. Otherwise, we'll check format of the
 # uncommitted code only.
 if [ -z "$uncommitted_code" ]
 then
  # Attempt to get name of facebook/rocksdb.git remote.
-  [ "$FORMAT_REMOTE" ] || FORMAT_REMOTE="$(git remote -v | grep 'facebook/rocksdb.git' | head -n 1 | cut -f 1)"
+  [ "$FORMAT_REMOTE" ] || FORMAT_REMOTE="$(LC_ALL=POSIX LANG=POSIX git remote -v | grep 'facebook/rocksdb.git' | head -n 1 | cut -f 1)"
  # Fall back on 'origin' if that fails
  [ "$FORMAT_REMOTE" ] || FORMAT_REMOTE=origin
-  # Use master branch from that remote
-  [ "$FORMAT_UPSTREAM" ] || FORMAT_UPSTREAM="$FORMAT_REMOTE/master"
+  # Use main branch from that remote
+  [ "$FORMAT_UPSTREAM" ] || FORMAT_UPSTREAM="$FORMAT_REMOTE/$(LC_ALL=POSIX LANG=POSIX git remote show $FORMAT_REMOTE | sed -n '/HEAD branch/s/.*: //p')"
  # Get the common ancestor with that remote branch. Everything after that
  # common ancestor would be considered the contents of a pull request, so
  # should be relevant for formatting fixes.
@@ -1561,6 +1561,7 @@ sub save_stdin_stdout_stderr {
 	::die_bug("Can't dup STDERR: $!");
    open $Global::original_stdin, "<&", "STDIN" or
 	::die_bug("Can't dup STDIN: $!");
+    $Global::is_terminal = (-t $Global::original_stderr) && !$ENV{'CIRCLECI'} && !$ENV{'TRAVIS'};
 }

 sub enough_file_handles {
@@ -1840,12 +1841,17 @@ sub start_another_job {
 }
 }

+$opt::min_progress_interval = 0;
+
 sub init_progress {
    # Uses:
    #   $opt::bar
    # Returns:
    #   list of computers for progress output
    $|=1;
+    if (not $Global::is_terminal) {
+      $opt::min_progress_interval = 30;
+    }
    if($opt::bar) {
 	return("","");
    }
@@ -1870,6 +1876,9 @@ sub drain_job_queue {
    }
    my $last_header="";
    my $sleep = 0.2;
+    my $last_left = 1000000000;
+    my $last_progress_time = 0;
+    my $ps_reported = 0;
    do {
        while($Global::total_running > 0) {
            debug($Global::total_running, "==", scalar
@@ -1880,14 +1889,38 @@ sub drain_job_queue {
 		    close $job->fh(0,"w");
 		}
 	    }
-            if($opt::progress) {
+            # When not connected to terminal, assume CI (e.g. CircleCI). In
+            # that case we want occasional progress output to prevent abort
+            # due to timeout with no output, but we also need to stop sending
+            # progress output if there has been no actual progress, so that
+            # the job can time out appropriately (CirecleCI: 10m) in case of
+            # a hung test. But without special output, it is extremely
+            # annoying to diagnose which test is hung, so we add that using
+            # `ps` below.
+            if($opt::progress and
+               ($Global::is_terminal or (time() - $last_progress_time) >= 30)) {
                my %progress = progress();
                if($last_header ne $progress{'header'}) {
                    print $Global::original_stderr "\n", $progress{'header'}, "\n";
                    $last_header = $progress{'header'};
                }
-                print $Global::original_stderr "\r",$progress{'status'};
-		flush $Global::original_stderr;
+                if ($Global::is_terminal) {
+                    print $Global::original_stderr "\r",$progress{'status'};
+                }
+                if ($last_left > $Global::left) {
+                    if (not $Global::is_terminal) {
+                        print $Global::original_stderr $progress{'status'},"\n";
+                    }
+                    $last_progress_time = time();
+                    $ps_reported = 0;
+                } elsif (not $ps_reported and (time() - $last_progress_time) >= 60) {
+                    # No progress in at least 60 seconds: run ps
+                    print $Global::original_stderr "\n";
+                    system("ps", "-wf");
+                    $ps_reported = 1;
+                }
+                $last_left = $Global::left;
+                flush $Global::original_stderr;
            }
 	    if($Global::total_running < $Global::max_jobs_running
 	       and not $Global::JobQueue->empty()) {
@@ -1921,7 +1954,7 @@ sub drain_job_queue {
 	     not $Global::start_no_new_jobs and not $Global::JobQueue->empty());
    if($opt::progress) {
 	my %progress = progress();
-	print $Global::original_stderr "\r", $progress{'status'}, "\n";
+	print $Global::original_stderr $opt::progress_sep, $progress{'status'}, "\n";
 	flush $Global::original_stderr;
    }
 }
@@ -1954,10 +1987,11 @@ sub progress {
    my $eta = "";
    my ($status,$header)=("","");
    if($opt::eta) {
-	my($total, $completed, $left, $pctcomplete, $avgtime, $this_eta) =
-	    compute_eta();
-	$eta = sprintf("ETA: %ds Left: %d AVG: %.2fs  ",
-		       $this_eta, $left, $avgtime);
+      my($total, $completed, $left, $pctcomplete, $avgtime, $this_eta) =
+        compute_eta();
+      $eta = sprintf("ETA: %ds Left: %d AVG: %.2fs  ",
+        $this_eta, $left, $avgtime);
+      $Global::left = $left;
    }
    my $termcols = terminal_columns();
    my @workers = sort keys %Global::host;
@@ -1,209 +0,0 @@
-#!/usr/bin/env python2.7
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-import argparse
-import commands
-import subprocess
-import sys
-import re
-import os
-import time
-
-
-#
-# Simple logger
-#
-
-class Log:
-
-    def __init__(self, filename):
-        self.filename = filename
-        self.f = open(self.filename, 'w+', 0)
-
-    def caption(self, str):
-        line = "\n##### %s #####\n" % str
-        if self.f:
-            self.f.write("%s \n" % line)
-        else:
-            print(line)
-
-    def error(self, str):
-        data = "\n\n##### ERROR ##### %s" % str
-        if self.f:
-            self.f.write("%s \n" % data)
-        else:
-            print(data)
-
-    def log(self, str):
-        if self.f:
-            self.f.write("%s \n" % str)
-        else:
-            print(str)
-
-#
-# Shell Environment
-#
-
-
-class Env(object):
-
-    def __init__(self, logfile, tests):
-        self.tests = tests
-        self.log = Log(logfile)
-
-    def shell(self, cmd, path=os.getcwd()):
-        if path:
-            os.chdir(path)
-
-        self.log.log("==== shell session ===========================")
-        self.log.log("%s> %s" % (path, cmd))
-        status = subprocess.call("cd %s; %s" % (path, cmd), shell=True,
-                                 stdout=self.log.f, stderr=self.log.f)
-        self.log.log("status = %s" % status)
-        self.log.log("============================================== \n\n")
-        return status
-
-    def GetOutput(self, cmd, path=os.getcwd()):
-        if path:
-            os.chdir(path)
-
-        self.log.log("==== shell session ===========================")
-        self.log.log("%s> %s" % (path, cmd))
-        status, out = commands.getstatusoutput(cmd)
-        self.log.log("status = %s" % status)
-        self.log.log("out = %s" % out)
-        self.log.log("============================================== \n\n")
-        return status, out
-
-#
-# Pre-commit checker
-#
-
-
-class PreCommitChecker(Env):
-
-    def __init__(self, args):
-        Env.__init__(self, args.logfile, args.tests)
-        self.ignore_failure = args.ignore_failure
-
-    #
-    #   Get commands for a given job from the determinator file
-    #
-    def get_commands(self, test):
-        status, out = self.GetOutput(
-            "RATIO=1 build_tools/rocksdb-lego-determinator %s" % test, ".")
-        return status, out
-
-    #
-    # Run a specific CI job
-    #
-    def run_test(self, test):
-        self.log.caption("Running test %s locally" % test)
-
-        # get commands for the CI job determinator
-        status, cmds = self.get_commands(test)
-        if status != 0:
-            self.log.error("Error getting commands for test %s" % test)
-            return False
-
-        # Parse the JSON to extract the commands to run
-        cmds = re.findall("'shell':'([^\']*)'", cmds)
-
-        if len(cmds) == 0:
-            self.log.log("No commands found")
-            return False
-
-        # Run commands
-        for cmd in cmds:
-            # Replace J=<..> with the local environment variable
-            if "J" in os.environ:
-                cmd = cmd.replace("J=1", "J=%s" % os.environ["J"])
-                cmd = cmd.replace("make ", "make -j%s " % os.environ["J"])
-            # Run the command
-            status = self.shell(cmd, ".")
-            if status != 0:
-                self.log.error("Error running command %s for test %s"
-                               % (cmd, test))
-                return False
-
-        return True
-
-    #
-    # Run specified CI jobs
-    #
-    def run_tests(self):
-        if not self.tests:
-            self.log.error("Invalid args. Please provide tests")
-            return False
-
-        self.print_separator()
-        self.print_row("TEST", "RESULT")
-        self.print_separator()
-
-        result = True
-        for test in self.tests:
-            start_time = time.time()
-            self.print_test(test)
-            result = self.run_test(test)
-            elapsed_min = (time.time() - start_time) / 60
-            if not result:
-                self.log.error("Error running test %s" % test)
-                self.print_result("FAIL (%dm)" % elapsed_min)
-                if not self.ignore_failure:
-                    return False
-                result = False
-            else:
-                self.print_result("PASS (%dm)" % elapsed_min)
-
-        self.print_separator()
-        return result
-
-    #
-    # Print a line
-    #
-    def print_separator(self):
-        print("".ljust(60, "-"))
-
-    #
-    # Print two colums
-    #
-    def print_row(self, c0, c1):
-        print("%s%s" % (c0.ljust(40), c1.ljust(20)))
-
-    def print_test(self, test):
-        print(test.ljust(40), end="")
-        sys.stdout.flush()
-
-    def print_result(self, result):
-        print(result.ljust(20))
-
-#
-# Main
-#
-parser = argparse.ArgumentParser(description='RocksDB pre-commit checker.')
-
-# --log <logfile>
-parser.add_argument('--logfile', default='/tmp/precommit-check.log',
-                    help='Log file. Default is /tmp/precommit-check.log')
-# --ignore_failure
-parser.add_argument('--ignore_failure', action='store_true', default=False,
-                    help='Stop when an error occurs')
-# <test ....>
-parser.add_argument('tests', nargs='+',
-                    help='CI test(s) to run. e.g: unit punit asan tsan ubsan')
-
-args = parser.parse_args()
-checker = PreCommitChecker(args)
-
-print("Please follow log %s" % checker.log.filename)
-
-if not checker.run_tests():
-    print("Error running tests. Please check log file %s"
-          % checker.log.filename)
-    sys.exit(1)
-
-sys.exit(0)
@@ -20,26 +20,11 @@ STAT_FILE=${STAT_FILE:-$(mktemp -t -u rocksdb_test_stats_XXXX)}

 function cleanup {
  rm -rf $DATA_DIR
-  rm -f $STAT_FILE.fillseq
-  rm -f $STAT_FILE.readrandom
-  rm -f $STAT_FILE.overwrite
-  rm -f $STAT_FILE.memtablefillreadrandom
+  rm -f $STAT_FILE.*
 }

 trap cleanup EXIT

-if [ -z $GIT_BRANCH ]; then
-  git_br=`git rev-parse --abbrev-ref HEAD`
-else
-  git_br=$(basename $GIT_BRANCH)
-fi
-
-if [ $git_br == "master" ]; then
-  git_br=""
-else
-  git_br="."$git_br
-fi
-
 make release

 # measure fillseq + fill up the DB for overwrite benchmark
@@ -273,7 +258,6 @@ common_in_mem_args="--db=/dev/shm/rocksdb \
    --value_size=100 \
    --compression_type=none \
    --compression_ratio=1 \
-    --hard_rate_limit=2 \
    --write_buffer_size=134217728 \
    --max_write_buffer_number=4 \
    --level0_file_num_compaction_trigger=8 \
@@ -286,12 +270,10 @@ common_in_mem_args="--db=/dev/shm/rocksdb \
    --sync=0 \
    --verify_checksum=1 \
    --delete_obsolete_files_period_micros=314572800 \
-    --max_grandparent_overlap_factor=10 \
    --use_plain_table=1 \
    --open_files=-1 \
    --mmap_read=1 \
    --mmap_write=0 \
-    --memtablerep=prefix_hash \
    --bloom_bits=10 \
    --bloom_locality=1 \
    --perf_level=0"
@@ -378,7 +360,7 @@ function send_to_ods {
    echo >&2 "ERROR: Key $key doesn't have a value."
    return
  fi
-  curl --silent "https://www.intern.facebook.com/intern/agent/ods_set.php?entity=rocksdb_build$git_br&key=$key&value=$value" \
+  curl --silent "https://www.intern.facebook.com/intern/agent/ods_set.php?entity=rocksdb_build&key=$key&value=$value" \
    --connect-timeout 60
 }

@@ -42,7 +42,7 @@ $RunOnly.Add("c_test") | Out-Null
 $RunOnly.Add("compact_on_deletion_collector_test") | Out-Null
 $RunOnly.Add("merge_test") | Out-Null
 $RunOnly.Add("stringappend_test") | Out-Null # Apparently incorrectly written
-$RunOnly.Add("backupable_db_test") | Out-Null # Disabled
+$RunOnly.Add("backup_engine_test") | Out-Null # Disabled
 $RunOnly.Add("timer_queue_test") | Out-Null # Not a gtest

 if($RunAll -and $SuiteRun -ne "") {
@@ -491,5 +491,3 @@ if(!$script:success) {
 }

 exit 0
-
-
@@ -10,6 +10,8 @@
 #include "rocksdb/cache.h"

 #include "cache/lru_cache.h"
+#include "rocksdb/secondary_cache.h"
+#include "rocksdb/utilities/customizable_util.h"
 #include "rocksdb/utilities/options_type.h"
 #include "util/string_util.h"

@@ -34,6 +36,13 @@ static std::unordered_map<std::string, OptionTypeInfo>
 };
 #endif  // ROCKSDB_LITE

+Status SecondaryCache::CreateFromString(
+    const ConfigOptions& config_options, const std::string& value,
+    std::shared_ptr<SecondaryCache>* result) {
+  return LoadSharedObject<SecondaryCache>(config_options, value, nullptr,
+                                          result);
+}
+
 Status Cache::CreateFromString(const ConfigOptions& config_options,
                               const std::string& value,
                               std::shared_ptr<Cache>* result) {
@@ -44,9 +53,9 @@ Status Cache::CreateFromString(const ConfigOptions& config_options,
  } else {
 #ifndef ROCKSDB_LITE
    LRUCacheOptions cache_opts;
-    status = OptionTypeInfo::ParseStruct(
-        config_options, "", &lru_cache_options_type_info, "", value,
-        reinterpret_cast<char*>(&cache_opts));
+    status = OptionTypeInfo::ParseStruct(config_options, "",
+                                         &lru_cache_options_type_info, "",
+                                         value, &cache_opts);
    if (status.ok()) {
      cache = NewLRUCache(cache_opts);
    }
@@ -1,8 +1,11 @@
-//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2013-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
 #ifndef GFLAGS
 #include <cstdio>
 int main() {
@@ -10,375 +13,8 @@ int main() {
  return 1;
 }
 #else
-
-#include <sys/types.h>
-
-#include <cinttypes>
-#include <cstdio>
-#include <limits>
-
-#include "port/port.h"
-#include "rocksdb/cache.h"
-#include "rocksdb/db.h"
-#include "rocksdb/env.h"
-#include "rocksdb/system_clock.h"
-#include "util/coding.h"
-#include "util/gflags_compat.h"
-#include "util/hash.h"
-#include "util/mutexlock.h"
-#include "util/random.h"
-
-using GFLAGS_NAMESPACE::ParseCommandLineFlags;
-
-static constexpr uint32_t KiB = uint32_t{1} << 10;
-static constexpr uint32_t MiB = KiB << 10;
-static constexpr uint64_t GiB = MiB << 10;
-
-DEFINE_uint32(threads, 16, "Number of concurrent threads to run.");
-DEFINE_uint64(cache_size, 1 * GiB,
-              "Number of bytes to use as a cache of uncompressed data.");
-DEFINE_uint32(num_shard_bits, 6, "shard_bits.");
-
-DEFINE_double(resident_ratio, 0.25,
-              "Ratio of keys fitting in cache to keyspace.");
-DEFINE_uint64(ops_per_thread, 0,
-              "Number of operations per thread. (Default: 5 * keyspace size)");
-DEFINE_uint32(value_bytes, 8 * KiB, "Size of each value added.");
-
-DEFINE_uint32(skew, 5, "Degree of skew in key selection");
-DEFINE_bool(populate_cache, true, "Populate cache before operations");
-
-DEFINE_uint32(lookup_insert_percent, 87,
-              "Ratio of lookup (+ insert on not found) to total workload "
-              "(expressed as a percentage)");
-DEFINE_uint32(insert_percent, 2,
-              "Ratio of insert to total workload (expressed as a percentage)");
-DEFINE_uint32(lookup_percent, 10,
-              "Ratio of lookup to total workload (expressed as a percentage)");
-DEFINE_uint32(erase_percent, 1,
-              "Ratio of erase to total workload (expressed as a percentage)");
-
-DEFINE_bool(use_clock_cache, false, "");
-
-namespace ROCKSDB_NAMESPACE {
-
-class CacheBench;
-namespace {
-// State shared by all concurrent executions of the same benchmark.
-class SharedState {
- public:
-  explicit SharedState(CacheBench* cache_bench)
-      : cv_(&mu_),
-        num_initialized_(0),
-        start_(false),
-        num_done_(0),
-        cache_bench_(cache_bench) {}
-
-  ~SharedState() {}
-
-  port::Mutex* GetMutex() {
-    return &mu_;
-  }
-
-  port::CondVar* GetCondVar() {
-    return &cv_;
-  }
-
-  CacheBench* GetCacheBench() const {
-    return cache_bench_;
-  }
-
-  void IncInitialized() {
-    num_initialized_++;
-  }
-
-  void IncDone() {
-    num_done_++;
-  }
-
-  bool AllInitialized() const { return num_initialized_ >= FLAGS_threads; }
-
-  bool AllDone() const { return num_done_ >= FLAGS_threads; }
-
-  void SetStart() {
-    start_ = true;
-  }
-
-  bool Started() const {
-    return start_;
-  }
-
- private:
-  port::Mutex mu_;
-  port::CondVar cv_;
-
-  uint64_t num_initialized_;
-  bool start_;
-  uint64_t num_done_;
-
-  CacheBench* cache_bench_;
-};
-
-// Per-thread state for concurrent executions of the same benchmark.
-struct ThreadState {
-  uint32_t tid;
-  Random64 rnd;
-  SharedState* shared;
-
-  ThreadState(uint32_t index, SharedState* _shared)
-      : tid(index), rnd(1000 + index), shared(_shared) {}
-};
-
-struct KeyGen {
-  char key_data[27];
-
-  Slice GetRand(Random64& rnd, uint64_t max_key) {
-    uint64_t raw = rnd.Next();
-    // Skew according to setting
-    for (uint32_t i = 0; i < FLAGS_skew; ++i) {
-      raw = std::min(raw, rnd.Next());
-    }
-    uint64_t key = FastRange64(raw, max_key);
-    // Variable size and alignment
-    size_t off = key % 8;
-    key_data[0] = char{42};
-    EncodeFixed64(key_data + 1, key);
-    key_data[9] = char{11};
-    EncodeFixed64(key_data + 10, key);
-    key_data[18] = char{4};
-    EncodeFixed64(key_data + 19, key);
-    return Slice(&key_data[off], sizeof(key_data) - off);
-  }
-};
-
-char* createValue(Random64& rnd) {
-  char* rv = new char[FLAGS_value_bytes];
-  // Fill with some filler data, and take some CPU time
-  for (uint32_t i = 0; i < FLAGS_value_bytes; i += 8) {
-    EncodeFixed64(rv + i, rnd.Next());
-  }
-  return rv;
-}
-
-void deleter(const Slice& /*key*/, void* value) {
-  delete[] static_cast<char*>(value);
-}
-}  // namespace
-
-class CacheBench {
-  static constexpr uint64_t kHundredthUint64 =
-      std::numeric_limits<uint64_t>::max() / 100U;
-
- public:
-  CacheBench()
-      : max_key_(static_cast<uint64_t>(FLAGS_cache_size / FLAGS_resident_ratio /
-                                       FLAGS_value_bytes)),
-        lookup_insert_threshold_(kHundredthUint64 *
-                                 FLAGS_lookup_insert_percent),
-        insert_threshold_(lookup_insert_threshold_ +
-                          kHundredthUint64 * FLAGS_insert_percent),
-        lookup_threshold_(insert_threshold_ +
-                          kHundredthUint64 * FLAGS_lookup_percent),
-        erase_threshold_(lookup_threshold_ +
-                         kHundredthUint64 * FLAGS_erase_percent) {
-    if (erase_threshold_ != 100U * kHundredthUint64) {
-      fprintf(stderr, "Percentages must add to 100.\n");
-      exit(1);
-    }
-    if (FLAGS_use_clock_cache) {
-      cache_ = NewClockCache(FLAGS_cache_size, FLAGS_num_shard_bits);
-      if (!cache_) {
-        fprintf(stderr, "Clock cache not supported.\n");
-        exit(1);
-      }
-    } else {
-      cache_ = NewLRUCache(FLAGS_cache_size, FLAGS_num_shard_bits);
-    }
-    if (FLAGS_ops_per_thread == 0) {
-      FLAGS_ops_per_thread = 5 * max_key_;
-    }
-  }
-
-  ~CacheBench() {}
-
-  void PopulateCache() {
-    Random64 rnd(1);
-    KeyGen keygen;
-    for (uint64_t i = 0; i < 2 * FLAGS_cache_size; i += FLAGS_value_bytes) {
-      cache_->Insert(keygen.GetRand(rnd, max_key_), createValue(rnd),
-                     FLAGS_value_bytes, &deleter);
-    }
-  }
-
-  bool Run() {
-    ROCKSDB_NAMESPACE::Env* env = ROCKSDB_NAMESPACE::Env::Default();
-    const auto& clock = env->GetSystemClock();
-
-    PrintEnv();
-    SharedState shared(this);
-    std::vector<std::unique_ptr<ThreadState> > threads(FLAGS_threads);
-    for (uint32_t i = 0; i < FLAGS_threads; i++) {
-      threads[i].reset(new ThreadState(i, &shared));
-      env->StartThread(ThreadBody, threads[i].get());
-    }
-    {
-      MutexLock l(shared.GetMutex());
-      while (!shared.AllInitialized()) {
-        shared.GetCondVar()->Wait();
-      }
-      // Record start time
-      uint64_t start_time = clock->NowMicros();
-
-      // Start all threads
-      shared.SetStart();
-      shared.GetCondVar()->SignalAll();
-
-      // Wait threads to complete
-      while (!shared.AllDone()) {
-        shared.GetCondVar()->Wait();
-      }
-
-      // Record end time
-      uint64_t end_time = clock->NowMicros();
-      double elapsed = static_cast<double>(end_time - start_time) * 1e-6;
-      uint32_t qps = static_cast<uint32_t>(
-          static_cast<double>(FLAGS_threads * FLAGS_ops_per_thread) / elapsed);
-      fprintf(stdout, "Complete in %.3f s; QPS = %u\n", elapsed, qps);
-    }
-    return true;
-  }
-
- private:
-  std::shared_ptr<Cache> cache_;
-  const uint64_t max_key_;
-  // Cumulative thresholds in the space of a random uint64_t
-  const uint64_t lookup_insert_threshold_;
-  const uint64_t insert_threshold_;
-  const uint64_t lookup_threshold_;
-  const uint64_t erase_threshold_;
-
-  static void ThreadBody(void* v) {
-    ThreadState* thread = static_cast<ThreadState*>(v);
-    SharedState* shared = thread->shared;
-
-    {
-      MutexLock l(shared->GetMutex());
-      shared->IncInitialized();
-      if (shared->AllInitialized()) {
-        shared->GetCondVar()->SignalAll();
-      }
-      while (!shared->Started()) {
-        shared->GetCondVar()->Wait();
-      }
-    }
-    thread->shared->GetCacheBench()->OperateCache(thread);
-
-    {
-      MutexLock l(shared->GetMutex());
-      shared->IncDone();
-      if (shared->AllDone()) {
-        shared->GetCondVar()->SignalAll();
-      }
-    }
-  }
-
-  void OperateCache(ThreadState* thread) {
-    // To use looked-up values
-    uint64_t result = 0;
-    // To hold handles for a non-trivial amount of time
-    Cache::Handle* handle = nullptr;
-    KeyGen gen;
-    for (uint64_t i = 0; i < FLAGS_ops_per_thread; i++) {
-      Slice key = gen.GetRand(thread->rnd, max_key_);
-      uint64_t random_op = thread->rnd.Next();
-      if (random_op < lookup_insert_threshold_) {
-        if (handle) {
-          cache_->Release(handle);
-          handle = nullptr;
-        }
-        // do lookup
-        handle = cache_->Lookup(key);
-        if (handle) {
-          // do something with the data
-          result += NPHash64(static_cast<char*>(cache_->Value(handle)),
-                             FLAGS_value_bytes);
-        } else {
-          // do insert
-          cache_->Insert(key, createValue(thread->rnd), FLAGS_value_bytes,
-                         &deleter, &handle);
-        }
-      } else if (random_op < insert_threshold_) {
-        if (handle) {
-          cache_->Release(handle);
-          handle = nullptr;
-        }
-        // do insert
-        cache_->Insert(key, createValue(thread->rnd), FLAGS_value_bytes,
-                       &deleter, &handle);
-      } else if (random_op < lookup_threshold_) {
-        if (handle) {
-          cache_->Release(handle);
-          handle = nullptr;
-        }
-        // do lookup
-        handle = cache_->Lookup(key);
-        if (handle) {
-          // do something with the data
-          result += NPHash64(static_cast<char*>(cache_->Value(handle)),
-                             FLAGS_value_bytes);
-        }
-      } else if (random_op < erase_threshold_) {
-        // do erase
-        cache_->Erase(key);
-      } else {
-        // Should be extremely unlikely (noop)
-        assert(random_op >= kHundredthUint64 * 100U);
-      }
-    }
-    if (handle) {
-      cache_->Release(handle);
-      handle = nullptr;
-    }
-  }
-
-  void PrintEnv() const {
-    printf("RocksDB version     : %d.%d\n", kMajorVersion, kMinorVersion);
-    printf("Number of threads   : %u\n", FLAGS_threads);
-    printf("Ops per thread      : %" PRIu64 "\n", FLAGS_ops_per_thread);
-    printf("Cache size          : %" PRIu64 "\n", FLAGS_cache_size);
-    printf("Num shard bits      : %u\n", FLAGS_num_shard_bits);
-    printf("Max key             : %" PRIu64 "\n", max_key_);
-    printf("Resident ratio      : %g\n", FLAGS_resident_ratio);
-    printf("Skew degree         : %u\n", FLAGS_skew);
-    printf("Populate cache      : %d\n", int{FLAGS_populate_cache});
-    printf("Lookup+Insert pct   : %u%%\n", FLAGS_lookup_insert_percent);
-    printf("Insert percentage   : %u%%\n", FLAGS_insert_percent);
-    printf("Lookup percentage   : %u%%\n", FLAGS_lookup_percent);
-    printf("Erase percentage    : %u%%\n", FLAGS_erase_percent);
-    printf("----------------------------\n");
-  }
-};
-}  // namespace ROCKSDB_NAMESPACE
-
+#include "rocksdb/cache_bench_tool.h"
 int main(int argc, char** argv) {
-  ParseCommandLineFlags(&argc, &argv, true);
-
-  if (FLAGS_threads <= 0) {
-    fprintf(stderr, "threads number <= 0\n");
-    exit(1);
-  }
-
-  ROCKSDB_NAMESPACE::CacheBench bench;
-  if (FLAGS_populate_cache) {
-    bench.PopulateCache();
-    printf("Population complete\n");
-    printf("----------------------------\n");
-  }
-  if (bench.Run()) {
-    return 0;
-  } else {
-    return 1;
-  }
+  return ROCKSDB_NAMESPACE::cache_bench_tool(argc, argv);
 }
-
 #endif  // GFLAGS
@@ -0,0 +1,924 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#ifdef GFLAGS
+#include <cinttypes>
+#include <cstddef>
+#include <cstdio>
+#include <limits>
+#include <memory>
+#include <set>
+#include <sstream>
+
+#include "db/db_impl/db_impl.h"
+#include "monitoring/histogram.h"
+#include "port/port.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/convenience.h"
+#include "rocksdb/db.h"
+#include "rocksdb/env.h"
+#include "rocksdb/secondary_cache.h"
+#include "rocksdb/system_clock.h"
+#include "rocksdb/table_properties.h"
+#include "table/block_based/block_based_table_reader.h"
+#include "table/block_based/cachable_entry.h"
+#include "util/coding.h"
+#include "util/gflags_compat.h"
+#include "util/hash.h"
+#include "util/mutexlock.h"
+#include "util/random.h"
+#include "util/stop_watch.h"
+#include "util/string_util.h"
+
+using GFLAGS_NAMESPACE::ParseCommandLineFlags;
+
+static constexpr uint32_t KiB = uint32_t{1} << 10;
+static constexpr uint32_t MiB = KiB << 10;
+static constexpr uint64_t GiB = MiB << 10;
+
+DEFINE_uint32(threads, 16, "Number of concurrent threads to run.");
+DEFINE_uint64(cache_size, 1 * GiB,
+              "Number of bytes to use as a cache of uncompressed data.");
+DEFINE_uint32(num_shard_bits, 6, "shard_bits.");
+
+DEFINE_double(resident_ratio, 0.25,
+              "Ratio of keys fitting in cache to keyspace.");
+DEFINE_uint64(ops_per_thread, 2000000U, "Number of operations per thread.");
+DEFINE_uint32(value_bytes, 8 * KiB, "Size of each value added.");
+
+DEFINE_uint32(skew, 5, "Degree of skew in key selection");
+DEFINE_bool(populate_cache, true, "Populate cache before operations");
+
+DEFINE_uint32(lookup_insert_percent, 87,
+              "Ratio of lookup (+ insert on not found) to total workload "
+              "(expressed as a percentage)");
+DEFINE_uint32(insert_percent, 2,
+              "Ratio of insert to total workload (expressed as a percentage)");
+DEFINE_uint32(lookup_percent, 10,
+              "Ratio of lookup to total workload (expressed as a percentage)");
+DEFINE_uint32(erase_percent, 1,
+              "Ratio of erase to total workload (expressed as a percentage)");
+DEFINE_bool(gather_stats, false,
+            "Whether to periodically simulate gathering block cache stats, "
+            "using one more thread.");
+DEFINE_uint32(
+    gather_stats_sleep_ms, 1000,
+    "How many milliseconds to sleep between each gathering of stats.");
+
+DEFINE_uint32(gather_stats_entries_per_lock, 256,
+              "For Cache::ApplyToAllEntries");
+DEFINE_bool(skewed, false, "If true, skew the key access distribution");
+#ifndef ROCKSDB_LITE
+DEFINE_string(secondary_cache_uri, "",
+              "Full URI for creating a custom secondary cache object");
+static class std::shared_ptr<ROCKSDB_NAMESPACE::SecondaryCache> secondary_cache;
+#endif  // ROCKSDB_LITE
+
+DEFINE_bool(use_clock_cache, false, "");
+
+// ## BEGIN stress_cache_key sub-tool options ##
+// See class StressCacheKey below.
+DEFINE_bool(stress_cache_key, false,
+            "If true, run cache key stress test instead");
+DEFINE_uint32(
+    sck_files_per_day, 2500000,
+    "(-stress_cache_key) Simulated files generated per simulated day");
+// NOTE: Giving each run a specified lifetime, rather than e.g. "until
+// first collision" ensures equal skew from start-up, when collisions are
+// less likely.
+DEFINE_uint32(sck_days_per_run, 90,
+              "(-stress_cache_key) Number of days to simulate in each run");
+// NOTE: The number of observed collisions directly affects the relative
+// accuracy of the predicted probabilities. 15 observations should be well
+// within factor-of-2 accuracy.
+DEFINE_uint32(
+    sck_min_collision, 15,
+    "(-stress_cache_key) Keep running until this many collisions seen");
+// sck_file_size_mb can be thought of as average file size. The simulation is
+// not precise enough to care about the distribution of file sizes; other
+// simulations (https://github.com/pdillinger/unique_id/tree/main/monte_carlo)
+// indicate the distribution only makes a small difference (e.g. < 2x factor)
+DEFINE_uint32(
+    sck_file_size_mb, 32,
+    "(-stress_cache_key) Simulated file size in MiB, for accounting purposes");
+DEFINE_uint32(sck_reopen_nfiles, 100,
+              "(-stress_cache_key) Simulate DB re-open average every n files");
+DEFINE_uint32(sck_restarts_per_day, 24,
+              "(-stress_cache_key) Average simulated process restarts per day "
+              "(across DBs)");
+DEFINE_uint32(
+    sck_db_count, 100,
+    "(-stress_cache_key) Parallel DBs in simulation sharing a block cache");
+DEFINE_uint32(
+    sck_table_bits, 20,
+    "(-stress_cache_key) Log2 number of tracked (live) files (across DBs)");
+// sck_keep_bits being well below full 128 bits amplifies the collision
+// probability so that the true probability can be estimated through observed
+// collisions. (More explanation below.)
+DEFINE_uint32(
+    sck_keep_bits, 50,
+    "(-stress_cache_key) Number of bits to keep from each cache key (<= 64)");
+// sck_randomize is used to validate whether cache key is performing "better
+// than random." Even with this setting, file offsets are not randomized.
+DEFINE_bool(sck_randomize, false,
+            "(-stress_cache_key) Randomize (hash) cache key");
+// See https://github.com/facebook/rocksdb/pull/9058
+DEFINE_bool(sck_footer_unique_id, false,
+            "(-stress_cache_key) Simulate using proposed footer unique id");
+// ## END stress_cache_key sub-tool options ##
+
+namespace ROCKSDB_NAMESPACE {
+
+class CacheBench;
+namespace {
+// State shared by all concurrent executions of the same benchmark.
+class SharedState {
+ public:
+  explicit SharedState(CacheBench* cache_bench)
+      : cv_(&mu_),
+        num_initialized_(0),
+        start_(false),
+        num_done_(0),
+        cache_bench_(cache_bench) {}
+
+  ~SharedState() {}
+
+  port::Mutex* GetMutex() { return &mu_; }
+
+  port::CondVar* GetCondVar() { return &cv_; }
+
+  CacheBench* GetCacheBench() const { return cache_bench_; }
+
+  void IncInitialized() { num_initialized_++; }
+
+  void IncDone() { num_done_++; }
+
+  bool AllInitialized() const { return num_initialized_ >= FLAGS_threads; }
+
+  bool AllDone() const { return num_done_ >= FLAGS_threads; }
+
+  void SetStart() { start_ = true; }
+
+  bool Started() const { return start_; }
+
+ private:
+  port::Mutex mu_;
+  port::CondVar cv_;
+
+  uint64_t num_initialized_;
+  bool start_;
+  uint64_t num_done_;
+
+  CacheBench* cache_bench_;
+};
+
+// Per-thread state for concurrent executions of the same benchmark.
+struct ThreadState {
+  uint32_t tid;
+  Random64 rnd;
+  SharedState* shared;
+  HistogramImpl latency_ns_hist;
+  uint64_t duration_us = 0;
+
+  ThreadState(uint32_t index, SharedState* _shared)
+      : tid(index), rnd(1000 + index), shared(_shared) {}
+};
+
+struct KeyGen {
+  char key_data[27];
+
+  Slice GetRand(Random64& rnd, uint64_t max_key, int max_log) {
+    uint64_t key = 0;
+    if (!FLAGS_skewed) {
+      uint64_t raw = rnd.Next();
+      // Skew according to setting
+      for (uint32_t i = 0; i < FLAGS_skew; ++i) {
+        raw = std::min(raw, rnd.Next());
+      }
+      key = FastRange64(raw, max_key);
+    } else {
+      key = rnd.Skewed(max_log);
+      if (key > max_key) {
+        key -= max_key;
+      }
+    }
+    // Variable size and alignment
+    size_t off = key % 8;
+    key_data[0] = char{42};
+    EncodeFixed64(key_data + 1, key);
+    key_data[9] = char{11};
+    EncodeFixed64(key_data + 10, key);
+    key_data[18] = char{4};
+    EncodeFixed64(key_data + 19, key);
+    return Slice(&key_data[off], sizeof(key_data) - off);
+  }
+};
+
+char* createValue(Random64& rnd) {
+  char* rv = new char[FLAGS_value_bytes];
+  // Fill with some filler data, and take some CPU time
+  for (uint32_t i = 0; i < FLAGS_value_bytes; i += 8) {
+    EncodeFixed64(rv + i, rnd.Next());
+  }
+  return rv;
+}
+
+// Callbacks for secondary cache
+size_t SizeFn(void* /*obj*/) { return FLAGS_value_bytes; }
+
+Status SaveToFn(void* obj, size_t /*offset*/, size_t size, void* out) {
+  memcpy(out, obj, size);
+  return Status::OK();
+}
+
+// Different deleters to simulate using deleter to gather
+// stats on the code origin and kind of cache entries.
+void deleter1(const Slice& /*key*/, void* value) {
+  delete[] static_cast<char*>(value);
+}
+void deleter2(const Slice& /*key*/, void* value) {
+  delete[] static_cast<char*>(value);
+}
+void deleter3(const Slice& /*key*/, void* value) {
+  delete[] static_cast<char*>(value);
+}
+
+Cache::CacheItemHelper helper1(SizeFn, SaveToFn, deleter1);
+Cache::CacheItemHelper helper2(SizeFn, SaveToFn, deleter2);
+Cache::CacheItemHelper helper3(SizeFn, SaveToFn, deleter3);
+}  // namespace
+
+class CacheBench {
+  static constexpr uint64_t kHundredthUint64 =
+      std::numeric_limits<uint64_t>::max() / 100U;
+
+ public:
+  CacheBench()
+      : max_key_(static_cast<uint64_t>(FLAGS_cache_size / FLAGS_resident_ratio /
+                                       FLAGS_value_bytes)),
+        lookup_insert_threshold_(kHundredthUint64 *
+                                 FLAGS_lookup_insert_percent),
+        insert_threshold_(lookup_insert_threshold_ +
+                          kHundredthUint64 * FLAGS_insert_percent),
+        lookup_threshold_(insert_threshold_ +
+                          kHundredthUint64 * FLAGS_lookup_percent),
+        erase_threshold_(lookup_threshold_ +
+                         kHundredthUint64 * FLAGS_erase_percent),
+        skewed_(FLAGS_skewed) {
+    if (erase_threshold_ != 100U * kHundredthUint64) {
+      fprintf(stderr, "Percentages must add to 100.\n");
+      exit(1);
+    }
+
+    max_log_ = 0;
+    if (skewed_) {
+      uint64_t max_key = max_key_;
+      while (max_key >>= 1) max_log_++;
+      if (max_key > (static_cast<uint64_t>(1) << max_log_)) max_log_++;
+    }
+
+    if (FLAGS_use_clock_cache) {
+      cache_ = NewClockCache(FLAGS_cache_size, FLAGS_num_shard_bits);
+      if (!cache_) {
+        fprintf(stderr, "Clock cache not supported.\n");
+        exit(1);
+      }
+    } else {
+      LRUCacheOptions opts(FLAGS_cache_size, FLAGS_num_shard_bits, false, 0.5);
+#ifndef ROCKSDB_LITE
+      if (!FLAGS_secondary_cache_uri.empty()) {
+        Status s = SecondaryCache::CreateFromString(
+            ConfigOptions(), FLAGS_secondary_cache_uri, &secondary_cache);
+        if (secondary_cache == nullptr) {
+          fprintf(
+              stderr,
+              "No secondary cache registered matching string: %s status=%s\n",
+              FLAGS_secondary_cache_uri.c_str(), s.ToString().c_str());
+          exit(1);
+        }
+        opts.secondary_cache = secondary_cache;
+      }
+#endif  // ROCKSDB_LITE
+
+      cache_ = NewLRUCache(opts);
+    }
+  }
+
+  ~CacheBench() {}
+
+  void PopulateCache() {
+    Random64 rnd(1);
+    KeyGen keygen;
+    for (uint64_t i = 0; i < 2 * FLAGS_cache_size; i += FLAGS_value_bytes) {
+      cache_->Insert(keygen.GetRand(rnd, max_key_, max_log_), createValue(rnd),
+                     &helper1, FLAGS_value_bytes);
+    }
+  }
+
+  bool Run() {
+    const auto clock = SystemClock::Default().get();
+
+    PrintEnv();
+    SharedState shared(this);
+    std::vector<std::unique_ptr<ThreadState> > threads(FLAGS_threads);
+    for (uint32_t i = 0; i < FLAGS_threads; i++) {
+      threads[i].reset(new ThreadState(i, &shared));
+      std::thread(ThreadBody, threads[i].get()).detach();
+    }
+
+    HistogramImpl stats_hist;
+    std::string stats_report;
+    std::thread stats_thread(StatsBody, &shared, &stats_hist, &stats_report);
+
+    uint64_t start_time;
+    {
+      MutexLock l(shared.GetMutex());
+      while (!shared.AllInitialized()) {
+        shared.GetCondVar()->Wait();
+      }
+      // Record start time
+      start_time = clock->NowMicros();
+
+      // Start all threads
+      shared.SetStart();
+      shared.GetCondVar()->SignalAll();
+
+      // Wait threads to complete
+      while (!shared.AllDone()) {
+        shared.GetCondVar()->Wait();
+      }
+    }
+
+    // Stats gathering is considered background work. This time measurement
+    // is for foreground work, and not really ideal for that. See below.
+    uint64_t end_time = clock->NowMicros();
+    stats_thread.join();
+
+    // Wall clock time - includes idle time if threads
+    // finish at different times (not ideal).
+    double elapsed_secs = static_cast<double>(end_time - start_time) * 1e-6;
+    uint32_t ops_per_sec = static_cast<uint32_t>(
+        1.0 * FLAGS_threads * FLAGS_ops_per_thread / elapsed_secs);
+    printf("Complete in %.3f s; Rough parallel ops/sec = %u\n", elapsed_secs,
+           ops_per_sec);
+
+    // Total time in each thread (more accurate throughput measure)
+    elapsed_secs = 0;
+    for (uint32_t i = 0; i < FLAGS_threads; i++) {
+      elapsed_secs += threads[i]->duration_us * 1e-6;
+    }
+    ops_per_sec = static_cast<uint32_t>(1.0 * FLAGS_threads *
+                                        FLAGS_ops_per_thread / elapsed_secs);
+    printf("Thread ops/sec = %u\n", ops_per_sec);
+
+    printf("\nOperation latency (ns):\n");
+    HistogramImpl combined;
+    for (uint32_t i = 0; i < FLAGS_threads; i++) {
+      combined.Merge(threads[i]->latency_ns_hist);
+    }
+    printf("%s", combined.ToString().c_str());
+
+    if (FLAGS_gather_stats) {
+      printf("\nGather stats latency (us):\n");
+      printf("%s", stats_hist.ToString().c_str());
+    }
+
+    printf("\n%s", stats_report.c_str());
+
+    return true;
+  }
+
+ private:
+  std::shared_ptr<Cache> cache_;
+  const uint64_t max_key_;
+  // Cumulative thresholds in the space of a random uint64_t
+  const uint64_t lookup_insert_threshold_;
+  const uint64_t insert_threshold_;
+  const uint64_t lookup_threshold_;
+  const uint64_t erase_threshold_;
+  const bool skewed_;
+  int max_log_;
+
+  // A benchmark version of gathering stats on an active block cache by
+  // iterating over it. The primary purpose is to measure the impact of
+  // gathering stats with ApplyToAllEntries on throughput- and
+  // latency-sensitive Cache users. Performance of stats gathering is
+  // also reported. The last set of gathered stats is also reported, for
+  // manual sanity checking for logical errors or other unexpected
+  // behavior of cache_bench or the underlying Cache.
+  static void StatsBody(SharedState* shared, HistogramImpl* stats_hist,
+                        std::string* stats_report) {
+    if (!FLAGS_gather_stats) {
+      return;
+    }
+    const auto clock = SystemClock::Default().get();
+    uint64_t total_key_size = 0;
+    uint64_t total_charge = 0;
+    uint64_t total_entry_count = 0;
+    std::set<Cache::DeleterFn> deleters;
+    StopWatchNano timer(clock);
+
+    for (;;) {
+      uint64_t time;
+      time = clock->NowMicros();
+      uint64_t deadline = time + uint64_t{FLAGS_gather_stats_sleep_ms} * 1000;
+
+      {
+        MutexLock l(shared->GetMutex());
+        for (;;) {
+          if (shared->AllDone()) {
+            std::ostringstream ostr;
+            ostr << "Most recent cache entry stats:\n"
+                 << "Number of entries: " << total_entry_count << "\n"
+                 << "Total charge: " << BytesToHumanString(total_charge) << "\n"
+                 << "Average key size: "
+                 << (1.0 * total_key_size / total_entry_count) << "\n"
+                 << "Average charge: "
+                 << BytesToHumanString(static_cast<uint64_t>(
+                        1.0 * total_charge / total_entry_count))
+                 << "\n"
+                 << "Unique deleters: " << deleters.size() << "\n";
+            *stats_report = ostr.str();
+            return;
+          }
+          if (clock->NowMicros() >= deadline) {
+            break;
+          }
+          uint64_t diff = deadline - std::min(clock->NowMicros(), deadline);
+          shared->GetCondVar()->TimedWait(diff + 1);
+        }
+      }
+
+      // Now gather stats, outside of mutex
+      total_key_size = 0;
+      total_charge = 0;
+      total_entry_count = 0;
+      deleters.clear();
+      auto fn = [&](const Slice& key, void* /*value*/, size_t charge,
+                    Cache::DeleterFn deleter) {
+        total_key_size += key.size();
+        total_charge += charge;
+        ++total_entry_count;
+        // Something slightly more expensive as in (future) stats by category
+        deleters.insert(deleter);
+      };
+      timer.Start();
+      Cache::ApplyToAllEntriesOptions opts;
+      opts.average_entries_per_lock = FLAGS_gather_stats_entries_per_lock;
+      shared->GetCacheBench()->cache_->ApplyToAllEntries(fn, opts);
+      stats_hist->Add(timer.ElapsedNanos() / 1000);
+    }
+  }
+
+  static void ThreadBody(ThreadState* thread) {
+    SharedState* shared = thread->shared;
+
+    {
+      MutexLock l(shared->GetMutex());
+      shared->IncInitialized();
+      if (shared->AllInitialized()) {
+        shared->GetCondVar()->SignalAll();
+      }
+      while (!shared->Started()) {
+        shared->GetCondVar()->Wait();
+      }
+    }
+    thread->shared->GetCacheBench()->OperateCache(thread);
+
+    {
+      MutexLock l(shared->GetMutex());
+      shared->IncDone();
+      if (shared->AllDone()) {
+        shared->GetCondVar()->SignalAll();
+      }
+    }
+  }
+
+  void OperateCache(ThreadState* thread) {
+    // To use looked-up values
+    uint64_t result = 0;
+    // To hold handles for a non-trivial amount of time
+    Cache::Handle* handle = nullptr;
+    KeyGen gen;
+    const auto clock = SystemClock::Default().get();
+    uint64_t start_time = clock->NowMicros();
+    StopWatchNano timer(clock);
+
+    for (uint64_t i = 0; i < FLAGS_ops_per_thread; i++) {
+      timer.Start();
+      Slice key = gen.GetRand(thread->rnd, max_key_, max_log_);
+      uint64_t random_op = thread->rnd.Next();
+      Cache::CreateCallback create_cb = [](const void* buf, size_t size,
+                                           void** out_obj,
+                                           size_t* charge) -> Status {
+        *out_obj = reinterpret_cast<void*>(new char[size]);
+        memcpy(*out_obj, buf, size);
+        *charge = size;
+        return Status::OK();
+      };
+
+      if (random_op < lookup_insert_threshold_) {
+        if (handle) {
+          cache_->Release(handle);
+          handle = nullptr;
+        }
+        // do lookup
+        handle = cache_->Lookup(key, &helper2, create_cb, Cache::Priority::LOW,
+                                true);
+        if (handle) {
+          // do something with the data
+          result += NPHash64(static_cast<char*>(cache_->Value(handle)),
+                             FLAGS_value_bytes);
+        } else {
+          // do insert
+          cache_->Insert(key, createValue(thread->rnd), &helper2,
+                         FLAGS_value_bytes, &handle);
+        }
+      } else if (random_op < insert_threshold_) {
+        if (handle) {
+          cache_->Release(handle);
+          handle = nullptr;
+        }
+        // do insert
+        cache_->Insert(key, createValue(thread->rnd), &helper3,
+                       FLAGS_value_bytes, &handle);
+      } else if (random_op < lookup_threshold_) {
+        if (handle) {
+          cache_->Release(handle);
+          handle = nullptr;
+        }
+        // do lookup
+        handle = cache_->Lookup(key, &helper2, create_cb, Cache::Priority::LOW,
+                                true);
+        if (handle) {
+          // do something with the data
+          result += NPHash64(static_cast<char*>(cache_->Value(handle)),
+                             FLAGS_value_bytes);
+        }
+      } else if (random_op < erase_threshold_) {
+        // do erase
+        cache_->Erase(key);
+      } else {
+        // Should be extremely unlikely (noop)
+        assert(random_op >= kHundredthUint64 * 100U);
+      }
+      thread->latency_ns_hist.Add(timer.ElapsedNanos());
+    }
+    if (handle) {
+      cache_->Release(handle);
+      handle = nullptr;
+    }
+    // Ensure computations on `result` are not optimized away.
+    if (result == 1) {
+      printf("You are extremely unlucky(2). Try again.\n");
+      exit(1);
+    }
+    thread->duration_us = clock->NowMicros() - start_time;
+  }
+
+  void PrintEnv() const {
+    printf("RocksDB version     : %d.%d\n", kMajorVersion, kMinorVersion);
+    printf("Number of threads   : %u\n", FLAGS_threads);
+    printf("Ops per thread      : %" PRIu64 "\n", FLAGS_ops_per_thread);
+    printf("Cache size          : %s\n",
+           BytesToHumanString(FLAGS_cache_size).c_str());
+    printf("Num shard bits      : %u\n", FLAGS_num_shard_bits);
+    printf("Max key             : %" PRIu64 "\n", max_key_);
+    printf("Resident ratio      : %g\n", FLAGS_resident_ratio);
+    printf("Skew degree         : %u\n", FLAGS_skew);
+    printf("Populate cache      : %d\n", int{FLAGS_populate_cache});
+    printf("Lookup+Insert pct   : %u%%\n", FLAGS_lookup_insert_percent);
+    printf("Insert percentage   : %u%%\n", FLAGS_insert_percent);
+    printf("Lookup percentage   : %u%%\n", FLAGS_lookup_percent);
+    printf("Erase percentage    : %u%%\n", FLAGS_erase_percent);
+    std::ostringstream stats;
+    if (FLAGS_gather_stats) {
+      stats << "enabled (" << FLAGS_gather_stats_sleep_ms << "ms, "
+            << FLAGS_gather_stats_entries_per_lock << "/lock)";
+    } else {
+      stats << "disabled";
+    }
+    printf("Gather stats        : %s\n", stats.str().c_str());
+    printf("----------------------------\n");
+  }
+};
+
+// cache_bench -stress_cache_key is an independent embedded tool for
+// estimating the probability of CacheKey collisions through simulation.
+// At a high level, it simulates generating SST files over many months,
+// keeping them in the DB and/or cache for some lifetime while staying
+// under resource caps, and checking for any cache key collisions that
+// arise among the set of live files. For efficient simulation, we make
+// some simplifying "pessimistic" assumptions (that only increase the
+// chance of the simulation reporting a collision relative to the chance
+// of collision in practice):
+// * Every generated file has a cache entry for every byte offset in the
+// file (contiguous range of cache keys)
+// * All of every file is cached for its entire lifetime. (Here "lifetime"
+// is technically the union of DB and Cache lifetime, though we only
+// model a generous DB lifetime, where space usage is always maximized.
+// In a effective Cache, lifetime in cache can only substantially exceed
+// lifetime in DB if there is little cache activity; cache activity is
+// required to hit cache key collisions.)
+//
+// It would be possible to track an exact set of cache key ranges for the
+// set of live files, but we would have no hope of observing collisions
+// (overlap in live files) in our simulation. We need to employ some way
+// of amplifying collision probability that allows us to predict the real
+// collision probability by extrapolation from observed collisions. Our
+// basic approach is to reduce each cache key range down to some smaller
+// number of bits, and limiting to bits that are shared over the whole
+// range.  Now we can observe collisions using a set of smaller stripped-down
+// (reduced) cache keys. Let's do some case analysis to understand why this
+// works:
+// * No collision in reduced key - because the reduction is a pure function
+// this implies no collision in the full keys
+// * Collision detected between two reduced keys - either
+//   * The reduction has dropped some structured uniqueness info (from one of
+// session counter or file number; file offsets are never materialized here).
+// This can only artificially inflate the observed and extrapolated collision
+// probabilities. We only have to worry about this in designing the reduction.
+//   * The reduction has preserved all the structured uniqueness in the cache
+// key, which means either
+//     * REJECTED: We have a uniqueness bug in generating cache keys, where
+// structured uniqueness info should have been different but isn't. In such a
+// case, increasing by 1 the number of bits kept after reduction would not
+// reduce observed probabilities by half. (In our observations, the
+// probabilities are reduced approximately by half.)
+//     * ACCEPTED: The lost unstructured uniqueness in the key determines the
+// probability that an observed collision would imply an overlap in ranges.
+// In short, dropping n bits from key would increase collision probability by
+// 2**n, assuming those n bits have full entropy in unstructured uniqueness.
+//
+// But we also have to account for the key ranges based on file size. If file
+// sizes are roughly 2**b offsets, using XOR in 128-bit cache keys for
+// "ranges", we know from other simulations (see
+// https://github.com/pdillinger/unique_id/) that that's roughly equivalent to
+// (less than 2x higher collision probability) using a cache key of size
+// 128 - b bits for the whole file. (This is the only place we make an
+// "optimistic" assumption, which is more than offset by the real
+// implementation stripping off 2 lower bits from block byte offsets for cache
+// keys. The simulation assumes byte offsets, which is net pessimistic.)
+//
+// So to accept the extrapolation as valid, we need to be confident that all
+// "lost" bits, excluding those covered by file offset, are full entropy.
+// Recall that we have assumed (verifiably, safely) that other structured data
+// (file number and session counter) are kept, not lost. Based on the
+// implementation comments for OffsetableCacheKey, the only potential hole here
+// is that we only have ~103 bits of entropy in "all new" session IDs, and in
+// extreme cases, there might be only 1 DB ID. However, because the upper ~39
+// bits of session ID are hashed, the combination of file number and file
+// offset only has to add to 25 bits (or more) to ensure full entropy in
+// unstructured uniqueness lost in the reduction. Typical file size of 32MB
+// suffices (at least for simulation purposes where we assume each file offset
+// occupies a cache key).
+//
+// Example results in comments on OffsetableCacheKey.
+class StressCacheKey {
+ public:
+  void Run() {
+    if (FLAGS_sck_footer_unique_id) {
+      // Proposed footer unique IDs are DB-independent and session-independent
+      // (but process-dependent) which is most easily simulated here by
+      // assuming 1 DB and (later below) no session resets without process
+      // reset.
+      FLAGS_sck_db_count = 1;
+    }
+
+    // Describe the simulated workload
+    uint64_t mb_per_day =
+        uint64_t{FLAGS_sck_files_per_day} * FLAGS_sck_file_size_mb;
+    printf("Total cache or DBs size: %gTiB  Writing %g MiB/s or %gTiB/day\n",
+           FLAGS_sck_file_size_mb / 1024.0 / 1024.0 *
+               std::pow(2.0, FLAGS_sck_table_bits),
+           mb_per_day / 86400.0, mb_per_day / 1024.0 / 1024.0);
+    // For extrapolating probability of any collisions from a number of
+    // observed collisions
+    multiplier_ = std::pow(2.0, 128 - FLAGS_sck_keep_bits) /
+                  (FLAGS_sck_file_size_mb * 1024.0 * 1024.0);
+    printf(
+        "Multiply by %g to correct for simulation losses (but still assume "
+        "whole file cached)\n",
+        multiplier_);
+    restart_nfiles_ = FLAGS_sck_files_per_day / FLAGS_sck_restarts_per_day;
+    double without_ejection =
+        std::pow(1.414214, FLAGS_sck_keep_bits) / FLAGS_sck_files_per_day;
+    // This should be a lower bound for -sck_randomize, usually a terribly
+    // rough lower bound.
+    // If observation is worse than this, then something has gone wrong.
+    printf(
+        "Without ejection, expect random collision after %g days (%g "
+        "corrected)\n",
+        without_ejection, without_ejection * multiplier_);
+    double with_full_table =
+        std::pow(2.0, FLAGS_sck_keep_bits - FLAGS_sck_table_bits) /
+        FLAGS_sck_files_per_day;
+    // This is an alternate lower bound for -sck_randomize, usually pretty
+    // accurate. Our cache keys should usually perform "better than random"
+    // but always no worse. (If observation is substantially worse than this,
+    // then something has gone wrong.)
+    printf(
+        "With ejection and full table, expect random collision after %g "
+        "days (%g corrected)\n",
+        with_full_table, with_full_table * multiplier_);
+    collisions_ = 0;
+
+    // Run until sufficient number of observed collisions.
+    for (int i = 1; collisions_ < FLAGS_sck_min_collision; i++) {
+      RunOnce();
+      if (collisions_ == 0) {
+        printf(
+            "No collisions after %d x %u days                              "
+            "                   \n",
+            i, FLAGS_sck_days_per_run);
+      } else {
+        double est = 1.0 * i * FLAGS_sck_days_per_run / collisions_;
+        printf("%" PRIu64
+               " collisions after %d x %u days, est %g days between (%g "
+               "corrected)        \n",
+               collisions_, i, FLAGS_sck_days_per_run, est, est * multiplier_);
+      }
+    }
+  }
+
+  void RunOnce() {
+    // Re-initialized simulated state
+    const size_t db_count = FLAGS_sck_db_count;
+    dbs_.reset(new TableProperties[db_count]{});
+    const size_t table_mask = (size_t{1} << FLAGS_sck_table_bits) - 1;
+    table_.reset(new uint64_t[table_mask + 1]{});
+    if (FLAGS_sck_keep_bits > 64) {
+      FLAGS_sck_keep_bits = 64;
+    }
+
+    // Details of which bits are dropped in reduction
+    uint32_t shift_away = 64 - FLAGS_sck_keep_bits;
+    // Shift away fewer potential file number bits (b) than potential
+    // session counter bits (a).
+    uint32_t shift_away_b = shift_away / 3;
+    uint32_t shift_away_a = shift_away - shift_away_b;
+
+    process_count_ = 0;
+    session_count_ = 0;
+    ResetProcess();
+
+    Random64 r{std::random_device{}()};
+
+    uint64_t max_file_count =
+        uint64_t{FLAGS_sck_files_per_day} * FLAGS_sck_days_per_run;
+    uint64_t file_size = FLAGS_sck_file_size_mb * uint64_t{1024} * 1024U;
+    uint32_t report_count = 0;
+    uint32_t collisions_this_run = 0;
+    size_t db_i = 0;
+
+    for (uint64_t file_count = 1; file_count <= max_file_count;
+         ++file_count, ++db_i) {
+      // Round-robin through DBs (this faster than %)
+      if (db_i >= db_count) {
+        db_i = 0;
+      }
+      // Any other periodic actions before simulating next file
+      if (!FLAGS_sck_footer_unique_id && r.OneIn(FLAGS_sck_reopen_nfiles)) {
+        ResetSession(db_i);
+      } else if (r.OneIn(restart_nfiles_)) {
+        ResetProcess();
+      }
+      // Simulate next file
+      OffsetableCacheKey ock;
+      dbs_[db_i].orig_file_number += 1;
+      // skip some file numbers for other file kinds, except in footer unique
+      // ID, orig_file_number here tracks process-wide generated SST file
+      // count.
+      if (!FLAGS_sck_footer_unique_id) {
+        dbs_[db_i].orig_file_number += (r.Next() & 3);
+      }
+      bool is_stable;
+      BlockBasedTable::SetupBaseCacheKey(&dbs_[db_i], /* ignored */ "",
+                                         /* ignored */ 42, file_size, &ock,
+                                         &is_stable);
+      assert(is_stable);
+      // Get a representative cache key, which later we analytically generalize
+      // to a range.
+      CacheKey ck = ock.WithOffset(0);
+      uint64_t reduced_key;
+      if (FLAGS_sck_randomize) {
+        reduced_key = GetSliceHash64(ck.AsSlice()) >> shift_away;
+      } else if (FLAGS_sck_footer_unique_id) {
+        // Special case: keep only file number, not session counter
+        uint32_t a = DecodeFixed32(ck.AsSlice().data() + 4) >> shift_away_a;
+        uint32_t b = DecodeFixed32(ck.AsSlice().data() + 12) >> shift_away_b;
+        reduced_key = (uint64_t{a} << 32) + b;
+      } else {
+        // Try to keep file number and session counter (shift away other bits)
+        uint32_t a = DecodeFixed32(ck.AsSlice().data()) << shift_away_a;
+        uint32_t b = DecodeFixed32(ck.AsSlice().data() + 12) >> shift_away_b;
+        reduced_key = (uint64_t{a} << 32) + b;
+      }
+      if (reduced_key == 0) {
+        // Unlikely, but we need to exclude tracking this value because we
+        // use it to mean "empty" in table. This case is OK as long as we
+        // don't hit it often.
+        printf("Hit Zero!                                                  \n");
+        file_count--;
+        continue;
+      }
+      uint64_t h =
+          NPHash64(reinterpret_cast<char*>(&reduced_key), sizeof(reduced_key));
+      // Skew expected lifetimes, for high variance (super-Poisson) variance
+      // in actual lifetimes.
+      size_t pos =
+          std::min(Lower32of64(h) & table_mask, Upper32of64(h) & table_mask);
+      if (table_[pos] == reduced_key) {
+        collisions_this_run++;
+        // Our goal is to predict probability of no collisions, not expected
+        // number of collisions. To make the distinction, we have to get rid
+        // of observing correlated collisions, which this takes care of:
+        ResetProcess();
+      } else {
+        // Replace (end of lifetime for file that was in this slot)
+        table_[pos] = reduced_key;
+      }
+
+      if (++report_count == FLAGS_sck_files_per_day) {
+        report_count = 0;
+        // Estimate fill %
+        size_t incr = table_mask / 1000;
+        size_t sampled_count = 0;
+        for (size_t i = 0; i <= table_mask; i += incr) {
+          if (table_[i] != 0) {
+            sampled_count++;
+          }
+        }
+        // Report
+        printf(
+            "%" PRIu64 " days, %" PRIu64 " proc, %" PRIu64
+            " sess, %u coll, occ %g%%, ejected %g%%   \r",
+            file_count / FLAGS_sck_files_per_day, process_count_,
+            session_count_, collisions_this_run, 100.0 * sampled_count / 1000.0,
+            100.0 * (1.0 - sampled_count / 1000.0 * table_mask / file_count));
+        fflush(stdout);
+      }
+    }
+    collisions_ += collisions_this_run;
+  }
+
+  void ResetSession(size_t i) {
+    dbs_[i].db_session_id = DBImpl::GenerateDbSessionId(nullptr);
+    session_count_++;
+  }
+
+  void ResetProcess() {
+    process_count_++;
+    DBImpl::TEST_ResetDbSessionIdGen();
+    for (size_t i = 0; i < FLAGS_sck_db_count; ++i) {
+      ResetSession(i);
+    }
+    if (FLAGS_sck_footer_unique_id) {
+      // For footer unique ID, this tracks process-wide generated SST file
+      // count.
+      dbs_[0].orig_file_number = 0;
+    }
+  }
+
+ private:
+  // Use db_session_id and orig_file_number from TableProperties
+  std::unique_ptr<TableProperties[]> dbs_;
+  std::unique_ptr<uint64_t[]> table_;
+  uint64_t process_count_ = 0;
+  uint64_t session_count_ = 0;
+  uint64_t collisions_ = 0;
+  uint32_t restart_nfiles_ = 0;
+  double multiplier_ = 0.0;
+};
+
+int cache_bench_tool(int argc, char** argv) {
+  ParseCommandLineFlags(&argc, &argv, true);
+
+  if (FLAGS_stress_cache_key) {
+    // Alternate tool
+    StressCacheKey().Run();
+    return 0;
+  }
+
+  if (FLAGS_threads <= 0) {
+    fprintf(stderr, "threads number <= 0\n");
+    exit(1);
+  }
+
+  ROCKSDB_NAMESPACE::CacheBench bench;
+  if (FLAGS_populate_cache) {
+    bench.PopulateCache();
+    printf("Population complete\n");
+    printf("----------------------------\n");
+  }
+  if (bench.Run()) {
+    return 0;
+  } else {
+    return 1;
+  }
+}  // namespace ROCKSDB_NAMESPACE
+}  // namespace ROCKSDB_NAMESPACE
+
+#endif  // GFLAGS
@@ -0,0 +1,72 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "cache/cache_entry_roles.h"
+
+#include <mutex>
+
+#include "port/lang.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+std::array<const char*, kNumCacheEntryRoles> kCacheEntryRoleToCamelString{{
+    "DataBlock",
+    "FilterBlock",
+    "FilterMetaBlock",
+    "DeprecatedFilterBlock",
+    "IndexBlock",
+    "OtherBlock",
+    "WriteBuffer",
+    "CompressionDictionaryBuildingBuffer",
+    "FilterConstruction",
+    "BlockBasedTableReader",
+    "Misc",
+}};
+
+std::array<const char*, kNumCacheEntryRoles> kCacheEntryRoleToHyphenString{{
+    "data-block",
+    "filter-block",
+    "filter-meta-block",
+    "deprecated-filter-block",
+    "index-block",
+    "other-block",
+    "write-buffer",
+    "compression-dictionary-building-buffer",
+    "filter-construction",
+    "block-based-table-reader",
+    "misc",
+}};
+
+namespace {
+
+struct Registry {
+  std::mutex mutex;
+  std::unordered_map<Cache::DeleterFn, CacheEntryRole> role_map;
+  void Register(Cache::DeleterFn fn, CacheEntryRole role) {
+    std::lock_guard<std::mutex> lock(mutex);
+    role_map[fn] = role;
+  }
+  std::unordered_map<Cache::DeleterFn, CacheEntryRole> Copy() {
+    std::lock_guard<std::mutex> lock(mutex);
+    return role_map;
+  }
+};
+
+Registry& GetRegistry() {
+  STATIC_AVOID_DESTRUCTION(Registry, registry);
+  return registry;
+}
+
+}  // namespace
+
+void RegisterCacheDeleterRole(Cache::DeleterFn fn, CacheEntryRole role) {
+  GetRegistry().Register(fn, role);
+}
+
+std::unordered_map<Cache::DeleterFn, CacheEntryRole> CopyCacheDeleterRoleMap() {
+  return GetRegistry().Copy();
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,137 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <array>
+#include <cstdint>
+#include <memory>
+#include <type_traits>
+#include <unordered_map>
+
+#include "rocksdb/cache.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// Classifications of block cache entries, for reporting statistics
+// Adding new enum to this class requires corresponding updates to
+// kCacheEntryRoleToCamelString and kCacheEntryRoleToHyphenString
+enum class CacheEntryRole {
+  // Block-based table data block
+  kDataBlock,
+  // Block-based table filter block (full or partitioned)
+  kFilterBlock,
+  // Block-based table metadata block for partitioned filter
+  kFilterMetaBlock,
+  // Block-based table deprecated filter block (old "block-based" filter)
+  kDeprecatedFilterBlock,
+  // Block-based table index block
+  kIndexBlock,
+  // Other kinds of block-based table block
+  kOtherBlock,
+  // WriteBufferManager reservations to account for memtable usage
+  kWriteBuffer,
+  // BlockBasedTableBuilder reservations to account for
+  // compression dictionary building buffer's memory usage
+  kCompressionDictionaryBuildingBuffer,
+  // Filter reservations to account for
+  // (new) bloom and ribbon filter construction's memory usage
+  kFilterConstruction,
+  // BlockBasedTableReader reservations to account for
+  // its memory usage
+  kBlockBasedTableReader,
+  // Default bucket, for miscellaneous cache entries. Do not use for
+  // entries that could potentially add up to large usage.
+  kMisc,
+};
+constexpr uint32_t kNumCacheEntryRoles =
+    static_cast<uint32_t>(CacheEntryRole::kMisc) + 1;
+
+extern std::array<const char*, kNumCacheEntryRoles>
+    kCacheEntryRoleToCamelString;
+extern std::array<const char*, kNumCacheEntryRoles>
+    kCacheEntryRoleToHyphenString;
+
+// To associate cache entries with their role, we use a hack on the
+// existing Cache interface. Because the deleter of an entry can authenticate
+// the code origin of an entry, we can elaborate the choice of deleter to
+// also encode role information, without inferring false role information
+// from entries not choosing to encode a role.
+//
+// The rest of this file is for handling mappings between deleters and
+// roles.
+
+// To infer a role from a deleter, the deleter must be registered. This
+// can be done "manually" with this function. This function is thread-safe,
+// and the registration mappings go into private but static storage. (Note
+// that DeleterFn is a function pointer, not std::function. Registrations
+// should not be too many.)
+void RegisterCacheDeleterRole(Cache::DeleterFn fn, CacheEntryRole role);
+
+// Gets a copy of the registered deleter -> role mappings. This is the only
+// function for reading the mappings made with RegisterCacheDeleterRole.
+// Why only this interface for reading?
+// * This function has to be thread safe, which could incur substantial
+// overhead. We should not pay this overhead for every deleter look-up.
+// * This is suitable for preparing for batch operations, like with
+// CacheEntryStatsCollector.
+// * The number of mappings should be sufficiently small (dozens).
+std::unordered_map<Cache::DeleterFn, CacheEntryRole> CopyCacheDeleterRoleMap();
+
+// ************************************************************** //
+// An automatic registration infrastructure. This enables code
+// to simply ask for a deleter associated with a particular type
+// and role, and registration is automatic. In a sense, this is
+// a small dependency injection infrastructure, because linking
+// in new deleter instantiations is essentially sufficient for
+// making stats collection (using CopyCacheDeleterRoleMap) aware
+// of them.
+
+namespace cache_entry_roles_detail {
+
+template <typename T, CacheEntryRole R>
+struct RegisteredDeleter {
+  RegisteredDeleter() { RegisterCacheDeleterRole(Delete, R); }
+
+  // These have global linkage to help ensure compiler optimizations do not
+  // break uniqueness for each <T,R>
+  static void Delete(const Slice& /* key */, void* value) {
+    // Supports T == Something[], unlike delete operator
+    std::default_delete<T>()(
+        static_cast<typename std::remove_extent<T>::type*>(value));
+  }
+};
+
+template <CacheEntryRole R>
+struct RegisteredNoopDeleter {
+  RegisteredNoopDeleter() { RegisterCacheDeleterRole(Delete, R); }
+
+  static void Delete(const Slice& /* key */, void* /* value */) {
+    // Here was `assert(value == nullptr);` but we can also put pointers
+    // to static data in Cache, for testing at least.
+  }
+};
+
+}  // namespace cache_entry_roles_detail
+
+// Get an automatically registered deleter for value type T and role R.
+// Based on C++ semantics, registration is invoked exactly once in a
+// thread-safe way on first call to this function, for each <T, R>.
+template <typename T, CacheEntryRole R>
+Cache::DeleterFn GetCacheEntryDeleterForRole() {
+  static cache_entry_roles_detail::RegisteredDeleter<T, R> reg;
+  return reg.Delete;
+}
+
+// Get an automatically registered no-op deleter (value should be nullptr)
+// and associated with role R. This is used for Cache "reservation" entries
+// such as for WriteBufferManager.
+template <CacheEntryRole R>
+Cache::DeleterFn GetNoopDeleterForRole() {
+  static cache_entry_roles_detail::RegisteredNoopDeleter<R> reg;
+  return reg.Delete;
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,183 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <array>
+#include <cstdint>
+#include <memory>
+#include <mutex>
+
+#include "cache/cache_helpers.h"
+#include "cache/cache_key.h"
+#include "port/lang.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/status.h"
+#include "rocksdb/system_clock.h"
+#include "test_util/sync_point.h"
+#include "util/coding_lean.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// A generic helper object for gathering stats about cache entries by
+// iterating over them with ApplyToAllEntries. This class essentially
+// solves the problem of slowing down a Cache with too many stats
+// collectors that could be sharing stat results, such as from multiple
+// column families or multiple DBs sharing a Cache. We employ a few
+// mitigations:
+// * Only one collector for a particular kind of Stats is alive
+// for each Cache. This is guaranteed using the Cache itself to hold
+// the collector.
+// * A mutex ensures only one thread is gathering stats for this
+// collector.
+// * The most recent gathered stats are saved and simply copied to
+// satisfy requests within a time window (default: 3 minutes) of
+// completion of the most recent stat gathering.
+//
+// Template parameter Stats must be copyable and trivially constructable,
+// as well as...
+// concept Stats {
+//   // Notification before applying callback to all entries
+//   void BeginCollection(Cache*, SystemClock*, uint64_t start_time_micros);
+//   // Get the callback to apply to all entries. `callback`
+//   // type must be compatible with Cache::ApplyToAllEntries
+//   callback GetEntryCallback();
+//   // Notification after applying callback to all entries
+//   void EndCollection(Cache*, SystemClock*, uint64_t end_time_micros);
+//   // Notification that a collection was skipped because of
+//   // sufficiently recent saved results.
+//   void SkippedCollection();
+// }
+template <class Stats>
+class CacheEntryStatsCollector {
+ public:
+  // Gather and save stats if saved stats are too old. (Use GetStats() to
+  // read saved stats.)
+  //
+  // Maximum allowed age for a "hit" on saved results is determined by the
+  // two interval parameters. Both set to 0 forces a re-scan. For example
+  // with min_interval_seconds=300 and min_interval_factor=100, if the last
+  // scan took 10s, we would only rescan ("miss") if the age in seconds of
+  // the saved results is > max(300, 100*10).
+  // Justification: scans can vary wildly in duration, e.g. from 0.02 sec
+  // to as much as 20 seconds, so we want to be able to cap the absolute
+  // and relative frequency of scans.
+  void CollectStats(int min_interval_seconds, int min_interval_factor) {
+    // Waits for any pending reader or writer (collector)
+    std::lock_guard<std::mutex> lock(working_mutex_);
+
+    uint64_t max_age_micros =
+        static_cast<uint64_t>(std::max(min_interval_seconds, 0)) * 1000000U;
+
+    if (last_end_time_micros_ > last_start_time_micros_ &&
+        min_interval_factor > 0) {
+      max_age_micros = std::max(
+          max_age_micros, min_interval_factor * (last_end_time_micros_ -
+                                                 last_start_time_micros_));
+    }
+
+    uint64_t start_time_micros = clock_->NowMicros();
+    if ((start_time_micros - last_end_time_micros_) > max_age_micros) {
+      last_start_time_micros_ = start_time_micros;
+      working_stats_.BeginCollection(cache_, clock_, start_time_micros);
+
+      cache_->ApplyToAllEntries(working_stats_.GetEntryCallback(), {});
+      TEST_SYNC_POINT_CALLBACK(
+          "CacheEntryStatsCollector::GetStats:AfterApplyToAllEntries", nullptr);
+
+      uint64_t end_time_micros = clock_->NowMicros();
+      last_end_time_micros_ = end_time_micros;
+      working_stats_.EndCollection(cache_, clock_, end_time_micros);
+    } else {
+      working_stats_.SkippedCollection();
+    }
+
+    // Save so that we don't need to wait for an outstanding collection in
+    // order to make of copy of the last saved stats
+    std::lock_guard<std::mutex> lock2(saved_mutex_);
+    saved_stats_ = working_stats_;
+  }
+
+  // Gets saved stats, regardless of age
+  void GetStats(Stats *stats) {
+    std::lock_guard<std::mutex> lock(saved_mutex_);
+    *stats = saved_stats_;
+  }
+
+  Cache *GetCache() const { return cache_; }
+
+  // Gets or creates a shared instance of CacheEntryStatsCollector in the
+  // cache itself, and saves into `ptr`. This shared_ptr will hold the
+  // entry in cache until all refs are destroyed.
+  static Status GetShared(Cache *cache, SystemClock *clock,
+                          std::shared_ptr<CacheEntryStatsCollector> *ptr) {
+    const Slice &cache_key = GetCacheKey();
+
+    Cache::Handle *h = cache->Lookup(cache_key);
+    if (h == nullptr) {
+      // Not yet in cache, but Cache doesn't provide a built-in way to
+      // avoid racing insert. So we double-check under a shared mutex,
+      // inspired by TableCache.
+      STATIC_AVOID_DESTRUCTION(std::mutex, static_mutex);
+      std::lock_guard<std::mutex> lock(static_mutex);
+
+      h = cache->Lookup(cache_key);
+      if (h == nullptr) {
+        auto new_ptr = new CacheEntryStatsCollector(cache, clock);
+        // TODO: non-zero charge causes some tests that count block cache
+        // usage to go flaky. Fix the problem somehow so we can use an
+        // accurate charge.
+        size_t charge = 0;
+        Status s = cache->Insert(cache_key, new_ptr, charge, Deleter, &h,
+                                 Cache::Priority::HIGH);
+        if (!s.ok()) {
+          assert(h == nullptr);
+          delete new_ptr;
+          return s;
+        }
+      }
+    }
+    // If we reach here, shared entry is in cache with handle `h`.
+    assert(cache->GetDeleter(h) == Deleter);
+
+    // Build an aliasing shared_ptr that keeps `ptr` in cache while there
+    // are references.
+    *ptr = MakeSharedCacheHandleGuard<CacheEntryStatsCollector>(cache, h);
+    return Status::OK();
+  }
+
+ private:
+  explicit CacheEntryStatsCollector(Cache *cache, SystemClock *clock)
+      : saved_stats_(),
+        working_stats_(),
+        last_start_time_micros_(0),
+        last_end_time_micros_(/*pessimistic*/ 10000000),
+        cache_(cache),
+        clock_(clock) {}
+
+  static void Deleter(const Slice &, void *value) {
+    delete static_cast<CacheEntryStatsCollector *>(value);
+  }
+
+  static const Slice &GetCacheKey() {
+    // For each template instantiation
+    static CacheKey ckey = CacheKey::CreateUniqueForProcessLifetime();
+    static Slice ckey_slice = ckey.AsSlice();
+    return ckey_slice;
+  }
+
+  std::mutex saved_mutex_;
+  Stats saved_stats_;
+
+  std::mutex working_mutex_;
+  Stats working_stats_;
+  uint64_t last_start_time_micros_;
+  uint64_t last_end_time_micros_;
+
+  Cache *const cache_;
+  SystemClock *const clock_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -111,4 +111,15 @@ class CacheHandleGuard {
  T* value_ = nullptr;
 };

+// Build an aliasing shared_ptr that keeps `handle` in cache while there
+// are references, but the pointer is to the value for that cache entry,
+// which must be of type T. This is copyable, unlike CacheHandleGuard, but
+// does not provide access to caching details.
+template <typename T>
+std::shared_ptr<T> MakeSharedCacheHandleGuard(Cache* cache,
+                                              Cache::Handle* handle) {
+  auto wrapper = std::make_shared<CacheHandleGuard<T>>(cache, handle);
+  return std::shared_ptr<T>(wrapper, static_cast<T*>(cache->Value(handle)));
+}
+
 }  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,344 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "cache/cache_key.h"
+
+#include <algorithm>
+#include <atomic>
+
+#include "rocksdb/cache.h"
+#include "table/unique_id_impl.h"
+#include "util/hash.h"
+#include "util/math.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// Value space plan for CacheKey:
+//
+// session_etc64_ | offset_etc64_ | Only generated by
+// ---------------+---------------+------------------------------------------
+//              0 |             0 | Reserved for "empty" CacheKey()
+//              0 |  > 0, < 1<<63 | CreateUniqueForCacheLifetime
+//              0 |      >= 1<<63 | CreateUniqueForProcessLifetime
+//            > 0 |           any | OffsetableCacheKey.WithOffset
+
+CacheKey CacheKey::CreateUniqueForCacheLifetime(Cache *cache) {
+  // +1 so that we can reserve all zeros for "unset" cache key
+  uint64_t id = cache->NewId() + 1;
+  // Ensure we don't collide with CreateUniqueForProcessLifetime
+  assert((id >> 63) == 0U);
+  return CacheKey(0, id);
+}
+
+CacheKey CacheKey::CreateUniqueForProcessLifetime() {
+  // To avoid colliding with CreateUniqueForCacheLifetime, assuming
+  // Cache::NewId counts up from zero, here we count down from UINT64_MAX.
+  // If this ever becomes a point of contention, we could sub-divide the
+  // space and use CoreLocalArray.
+  static std::atomic<uint64_t> counter{UINT64_MAX};
+  uint64_t id = counter.fetch_sub(1, std::memory_order_relaxed);
+  // Ensure we don't collide with CreateUniqueForCacheLifetime
+  assert((id >> 63) == 1U);
+  return CacheKey(0, id);
+}
+
+// Value plan for CacheKeys from OffsetableCacheKey, assuming that
+// db_session_ids are generated from a base_session_id and
+// session_id_counter (by SemiStructuredUniqueIdGen+EncodeSessionId
+// in DBImpl::GenerateDbSessionId):
+//
+// Conceptual inputs:
+//   db_id                   (unstructured, from GenerateRawUniqueId or equiv)
+//                           * could be shared between cloned DBs but rare
+//                           * could be constant, if session id suffices
+//   base_session_id         (unstructured, from GenerateRawUniqueId)
+//   session_id_counter      (structured)
+//                           * usually much smaller than 2**24
+//   file_number             (structured)
+//                           * usually smaller than 2**24
+//   offset_in_file          (structured, might skip lots of values)
+//                           * usually smaller than 2**32
+//   max_offset              determines placement of file_number to prevent
+//                           overlapping with offset
+//
+// Outputs come from bitwise-xor of the constituent pieces, low bits on left:
+//
+// |------------------------- session_etc64 -------------------------|
+// | +++++++++++++++ base_session_id (lower 64 bits) +++++++++++++++ |
+// |-----------------------------------------------------------------|
+// | session_id_counter ...|                                         |
+// |-----------------------------------------------------------------|
+// |                                               | ... file_number |
+// |                                               | overflow & meta |
+// |-----------------------------------------------------------------|
+//
+//
+// |------------------------- offset_etc64 --------------------------|
+// | hash of: ++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
+// |  * base_session_id (upper ~39 bits)                             |
+// |  * db_id (~122 bits entropy)                                    |
+// |-----------------------------------------------------------------|
+// | offset_in_file ............... |                                |
+// |-----------------------------------------------------------------|
+// |                                              | file_number, 0-3 |
+// |                                              | lower bytes      |
+// |-----------------------------------------------------------------|
+//
+// Based on max_offset, a maximal number of bytes 0..3 is chosen for
+// including from lower bits of file_number in offset_etc64. The choice
+// is encoded in two bits of metadata going into session_etc64, though
+// the common case of 3 bytes is encoded as 0 so that session_etc64
+// is unmodified by file_number concerns in the common case.
+//
+// There is nothing preventing "file number overflow & meta" from meeting
+// and overlapping with session_id_counter, but reaching such a case requires
+// an intractable combination of large file offsets (thus at least some large
+// files), large file numbers (thus large number of files generated), and
+// large number of session IDs generated in a single process. A trillion each
+// (2**40) of session ids, offsets, and file numbers comes to 120 bits.
+// With two bits of metadata and byte granularity, this is on the verge of
+// overlap, but even in the overlap case, it doesn't seem likely that
+// a file from billions of files or session ids ago will still be live
+// or cached.
+//
+// In fact, if our SST files are all < 4TB (see
+// BlockBasedTable::kMaxFileSizeStandardEncoding), then SST files generated
+// in a single process are guaranteed to have unique cache keys, unless/until
+// number session ids * max file number = 2**86, e.g. 1 trillion DB::Open in
+// a single process and 64 trillion files generated. Even at that point, to
+// see a collision we would need a miraculous re-synchronization of session
+// id and file number, along with a live file or stale cache entry from
+// trillions of files ago.
+//
+// How https://github.com/pdillinger/unique_id applies here:
+// Every bit of output always includes "unstructured" uniqueness bits and
+// often combines with "structured" uniqueness bits. The "unstructured" bits
+// change infrequently: only when we cannot guarantee our state tracking for
+// "structured" uniqueness hasn't been cloned. Using a static
+// SemiStructuredUniqueIdGen for db_session_ids, this means we only get an
+// "all new" session id when a new process uses RocksDB. (Between processes,
+// we don't know if a DB or other persistent storage has been cloned. We
+// assume that if VM hot cloning is used, subsequently generated SST files
+// do not interact.) Within a process, only the session_lower of the
+// db_session_id changes incrementally ("structured" uniqueness).
+//
+// This basically means that our offsets, counters and file numbers allow us
+// to do somewhat "better than random" (birthday paradox) while in the
+// degenerate case of completely new session for each tiny file, we still
+// have strong uniqueness properties from the birthday paradox, with ~103
+// bit session IDs or up to 128 bits entropy with different DB IDs sharing a
+// cache.
+//
+// More collision probability analysis:
+// Suppose a RocksDB host generates (generously) 2 GB/s (10TB data, 17 DWPD)
+// with average process/session lifetime of (pessimistically) 4 minutes.
+// In 180 days (generous allowable data lifespan), we generate 31 million GB
+// of data, or 2^55 bytes, and 2^16 "all new" session IDs.
+//
+// First, suppose this is in a single DB (lifetime 180 days):
+// 128 bits cache key size
+// - 55 <- ideal size for byte offsets + file numbers
+// -  2 <- bits for offsets and file numbers not exactly powers of two
+// -  2 <- bits for file number encoding metadata
+// +  2 <- bits saved not using byte offsets in BlockBasedTable::GetCacheKey
+// ----
+//   71 <- bits remaining for distinguishing session IDs
+// The probability of a collision in 71 bits of session ID data is less than
+// 1 in 2**(71 - (2 * 16)), or roughly 1 in a trillion. And this assumes all
+// data from the last 180 days is in cache for potential collision, and that
+// cache keys under each session id exhaustively cover the remaining 57 bits
+// while in reality they'll only cover a small fraction of it.
+//
+// Although data could be transferred between hosts, each host has its own
+// cache and we are already assuming a high rate of "all new" session ids.
+// So this doesn't really change the collision calculation. Across a fleet
+// of 1 million, each with <1 in a trillion collision possibility,
+// fleetwide collision probability is <1 in a million.
+//
+// Now suppose we have many DBs per host, say 2**10, with same host-wide write
+// rate and process/session lifetime. File numbers will be ~10 bits smaller
+// and we will have 2**10 times as many session IDs because of simultaneous
+// lifetimes. So now collision chance is less than 1 in 2**(81 - (2 * 26)),
+// or roughly 1 in a billion.
+//
+// Suppose instead we generated random or hashed cache keys for each
+// (compressed) block. For 1KB compressed block size, that is 2^45 cache keys
+// in 180 days. Collision probability is more easily estimated at roughly
+// 1 in 2**(128 - (2 * 45)) or roughly 1 in a trillion (assuming all
+// data from the last 180 days is in cache, but NOT the other assumption
+// for the 1 in a trillion estimate above).
+//
+//
+// Collision probability estimation through simulation:
+// A tool ./cache_bench -stress_cache_key broadly simulates host-wide cache
+// activity over many months, by making some pessimistic simplifying
+// assumptions. See class StressCacheKey in cache_bench_tool.cc for details.
+// Here is some sample output with
+// `./cache_bench -stress_cache_key -sck_keep_bits=40`:
+//
+//   Total cache or DBs size: 32TiB  Writing 925.926 MiB/s or 76.2939TiB/day
+//   Multiply by 9.22337e+18 to correct for simulation losses (but still
+//   assume whole file cached)
+//
+// These come from default settings of 2.5M files per day of 32 MB each, and
+// `-sck_keep_bits=40` means that to represent a single file, we are only
+// keeping 40 bits of the 128-bit (base) cache key.  With file size of 2**25
+// contiguous keys (pessimistic), our simulation is about 2\*\*(128-40-25) or
+// about 9 billion billion times more prone to collision than reality.
+//
+// More default assumptions, relatively pessimistic:
+// * 100 DBs in same process (doesn't matter much)
+// * Re-open DB in same process (new session ID related to old session ID) on
+// average every 100 files generated
+// * Restart process (all new session IDs unrelated to old) 24 times per day
+//
+// After enough data, we get a result at the end (-sck_keep_bits=40):
+//
+//   (keep 40 bits)  17 collisions after 2 x 90 days, est 10.5882 days between
+//                   (9.76592e+19 corrected)
+//
+// If we believe the (pessimistic) simulation and the mathematical
+// extrapolation, we would need to run a billion machines all for 97 billion
+// days to expect a cache key collision. To help verify that our extrapolation
+// ("corrected") is robust, we can make our simulation more precise with
+// `-sck_keep_bits=41` and `42`, which takes more running time to get enough
+// collision data:
+//
+//   (keep 41 bits)  16 collisions after 4 x 90 days, est 22.5 days between
+//                   (1.03763e+20 corrected)
+//   (keep 42 bits)  19 collisions after 10 x 90 days, est 47.3684 days between
+//                   (1.09224e+20 corrected)
+//
+// The extrapolated prediction is very close. If anything, we might have some
+// very small losses of structured data (see class StressCacheKey in
+// cache_bench_tool.cc) leading to more accurate & more attractive prediction
+// with more bits kept.
+//
+// With the `-sck_randomize` option, we can see that typical workloads like
+// above have lower collision probability than "random" cache keys (note:
+// offsets still non-randomized) by a modest amount (roughly 20x less collision
+// prone than random), which should make us reasonably comfortable even in
+// "degenerate" cases (e.g. repeatedly launch a process to generate 1 file
+// with SstFileWriter):
+//
+//   (rand 40 bits) 197 collisions after 1 x 90 days, est 0.456853 days between
+//                  (4.21372e+18 corrected)
+//
+// We can see that with more frequent process restarts (all new session IDs),
+// we get closer to the "random" cache key performance:
+//
+//   (-sck_restarts_per_day=5000): 140 collisions after 1 x 90 days, ...
+//                  (5.92931e+18 corrected)
+//
+// Other tests have been run to validate other conditions behave as expected,
+// never behaving "worse than random" unless we start chopping off structured
+// data.
+//
+//
+// Conclusion: Even in extreme cases, rapidly burning through "all new" IDs
+// that only arise when a new process is started, the chance of any cache key
+// collisions in a giant fleet of machines is negligible. Especially when
+// processes live for hours or days, the chance of a cache key collision is
+// likely more plausibly due to bad hardware than to bad luck in random
+// session ID data. Software defects are surely more likely to cause corruption
+// than both of those.
+//
+// TODO: Nevertheless / regardless, an efficient way to detect (and thus
+// quantify) block cache corruptions, including collisions, should be added.
+OffsetableCacheKey::OffsetableCacheKey(const std::string &db_id,
+                                       const std::string &db_session_id,
+                                       uint64_t file_number,
+                                       uint64_t max_offset) {
+#ifndef NDEBUG
+  max_offset_ = max_offset;
+#endif
+  // Closely related to GetSstInternalUniqueId, but only need 128 bits and
+  // need to include an offset within the file.
+  // See also https://github.com/pdillinger/unique_id for background.
+  uint64_t session_upper = 0;  // Assignment to appease clang-analyze
+  uint64_t session_lower = 0;  // Assignment to appease clang-analyze
+  {
+    Status s = DecodeSessionId(db_session_id, &session_upper, &session_lower);
+    if (!s.ok()) {
+      // A reasonable fallback in case malformed
+      Hash2x64(db_session_id.data(), db_session_id.size(), &session_upper,
+               &session_lower);
+    }
+  }
+
+  // Hash the session upper (~39 bits entropy) and DB id (120+ bits entropy)
+  // for more global uniqueness entropy.
+  // (It is possible that many DBs descended from one common DB id are copied
+  // around and proliferate, in which case session id is critical, but it is
+  // more common for different DBs to have different DB ids.)
+  uint64_t db_hash = Hash64(db_id.data(), db_id.size(), session_upper);
+
+  // This establishes the db+session id part of the cache key.
+  //
+  // Exactly preserve (in common cases; see modifiers below) session lower to
+  // ensure that session ids generated during the same process lifetime are
+  // guaranteed unique.
+  //
+  // We put this first for CommonPrefixSlice(), so that a small-ish set of
+  // cache key prefixes to cover entries relevant to any DB.
+  session_etc64_ = session_lower;
+  // This provides extra entopy in case of different DB id or process
+  // generating a session id, but is also partly/variably obscured by
+  // file_number and offset (see below).
+  offset_etc64_ = db_hash;
+
+  // Into offset_etc64_ we are (eventually) going to pack & xor in an offset and
+  // a file_number, but we might need the file_number to overflow into
+  // session_etc64_. (There must only be one session_etc64_ value per
+  // file, and preferably shared among many files.)
+  //
+  // Figure out how many bytes of file_number we are going to be able to
+  // pack in with max_offset, though our encoding will only support packing
+  // in up to 3 bytes of file_number. (16M file numbers is enough for a new
+  // file number every second for half a year.)
+  int file_number_bytes_in_offset_etc =
+      (63 - FloorLog2(max_offset | 0x100000000U)) / 8;
+  int file_number_bits_in_offset_etc = file_number_bytes_in_offset_etc * 8;
+
+  // Assert two bits of metadata
+  assert(file_number_bytes_in_offset_etc >= 0 &&
+         file_number_bytes_in_offset_etc <= 3);
+  // Assert we couldn't have used a larger allowed number of bytes (shift
+  // would chop off bytes).
+  assert(file_number_bytes_in_offset_etc == 3 ||
+         (max_offset << (file_number_bits_in_offset_etc + 8) >>
+          (file_number_bits_in_offset_etc + 8)) != max_offset);
+
+  uint64_t mask = (uint64_t{1} << (file_number_bits_in_offset_etc)) - 1;
+  // Pack into high bits of etc so that offset can go in low bits of etc
+  // TODO: could be EndianSwapValue?
+  uint64_t offset_etc_modifier = ReverseBits(file_number & mask);
+  assert(offset_etc_modifier << file_number_bits_in_offset_etc == 0U);
+
+  // Overflow and 3 - byte count (likely both zero) go into session_id part
+  uint64_t session_etc_modifier =
+      (file_number >> file_number_bits_in_offset_etc << 2) |
+      static_cast<uint64_t>(3 - file_number_bytes_in_offset_etc);
+  // Packed into high bits to minimize interference with session id counter.
+  session_etc_modifier = ReverseBits(session_etc_modifier);
+
+  // Assert session_id part is only modified in extreme cases
+  assert(session_etc_modifier == 0 || file_number > /*3 bytes*/ 0xffffffU ||
+         max_offset > /*5 bytes*/ 0xffffffffffU);
+
+  // Xor in the modifiers
+  session_etc64_ ^= session_etc_modifier;
+  offset_etc64_ ^= offset_etc_modifier;
+
+  // Although DBImpl guarantees (in recent versions) that session_lower is not
+  // zero, that's not entirely sufficient to guarantee that session_etc64_ is
+  // not zero (so that the 0 case can be used by CacheKey::CreateUnique*)
+  if (session_etc64_ == 0U) {
+    session_etc64_ = session_upper | 1U;
+  }
+  assert(session_etc64_ != 0);
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,132 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <cstdint>
+
+#include "rocksdb/rocksdb_namespace.h"
+#include "rocksdb/slice.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Cache;
+
+// A standard holder for fixed-size block cache keys (and for related caches).
+// They are created through one of these, each using its own range of values:
+// * CacheKey::CreateUniqueForCacheLifetime
+// * CacheKey::CreateUniqueForProcessLifetime
+// * Default ctor ("empty" cache key)
+// * OffsetableCacheKey->WithOffset
+//
+// The first two use atomic counters to guarantee uniqueness over the given
+// lifetime and the last uses a form of universally unique identifier for
+// uniqueness with very high probabilty (and guaranteed for files generated
+// during a single process lifetime).
+//
+// CacheKeys are currently used by calling AsSlice() to pass as a key to
+// Cache. For performance, the keys are endianness-dependent (though otherwise
+// portable). (Persistable cache entries are not intended to cross platforms.)
+class CacheKey {
+ public:
+  // For convenience, constructs an "empty" cache key that is never returned
+  // by other means.
+  inline CacheKey() : session_etc64_(), offset_etc64_() {}
+
+  inline bool IsEmpty() const {
+    return (session_etc64_ == 0) & (offset_etc64_ == 0);
+  }
+
+  // Use this cache key as a Slice (byte order is endianness-dependent)
+  inline Slice AsSlice() const {
+    static_assert(sizeof(*this) == 16, "Standardized on 16-byte cache key");
+    assert(!IsEmpty());
+    return Slice(reinterpret_cast<const char *>(this), sizeof(*this));
+  }
+
+  // Create a CacheKey that is unique among others associated with this Cache
+  // instance. Depends on Cache::NewId. This is useful for block cache
+  // "reservations".
+  static CacheKey CreateUniqueForCacheLifetime(Cache *cache);
+
+  // Create a CacheKey that is unique among others for the lifetime of this
+  // process. This is useful for saving in a static data member so that
+  // different DB instances can agree on a cache key for shared entities,
+  // such as for CacheEntryStatsCollector.
+  static CacheKey CreateUniqueForProcessLifetime();
+
+ protected:
+  friend class OffsetableCacheKey;
+  CacheKey(uint64_t session_etc64, uint64_t offset_etc64)
+      : session_etc64_(session_etc64), offset_etc64_(offset_etc64) {}
+  uint64_t session_etc64_;
+  uint64_t offset_etc64_;
+};
+
+// A file-specific generator of cache keys, sometimes referred to as the
+// "base" cache key for a file because all the cache keys for various offsets
+// within the file are computed using simple arithmetic. The basis for the
+// general approach is dicussed here: https://github.com/pdillinger/unique_id
+// Heavily related to GetUniqueIdFromTableProperties.
+//
+// If the db_id, db_session_id, and file_number come from the file's table
+// properties, then the keys will be stable across DB::Open/Close, backup/
+// restore, import/export, etc.
+//
+// This class "is a" CacheKey only privately so that it is not misused as
+// a ready-to-use CacheKey.
+class OffsetableCacheKey : private CacheKey {
+ public:
+  // For convenience, constructs an "empty" cache key that should not be used.
+  inline OffsetableCacheKey() : CacheKey() {}
+
+  // Constructs an OffsetableCacheKey with the given information about a file.
+  // max_offset is based on file size (see WithOffset) and is required here to
+  // choose an appropriate (sub-)encoding. This constructor never generates an
+  // "empty" base key.
+  OffsetableCacheKey(const std::string &db_id, const std::string &db_session_id,
+                     uint64_t file_number, uint64_t max_offset);
+
+  inline bool IsEmpty() const {
+    bool result = session_etc64_ == 0;
+    assert(!(offset_etc64_ > 0 && result));
+    return result;
+  }
+
+  // Construct a CacheKey for an offset within a file, which must be
+  // <= max_offset provided in constructor. An offset is not necessarily a
+  // byte offset if a smaller unique identifier of keyable offsets is used.
+  //
+  // This class was designed to make this hot code extremely fast.
+  inline CacheKey WithOffset(uint64_t offset) const {
+    assert(!IsEmpty());
+    assert(offset <= max_offset_);
+    return CacheKey(session_etc64_, offset_etc64_ ^ offset);
+  }
+
+  // The "common prefix" is a shared prefix for all the returned CacheKeys,
+  // that also happens to usually be the same among many files in the same DB,
+  // so is efficient and highly accurate (not perfectly) for DB-specific cache
+  // dump selection (but not file-specific).
+  static constexpr size_t kCommonPrefixSize = 8;
+  inline Slice CommonPrefixSlice() const {
+    static_assert(sizeof(session_etc64_) == kCommonPrefixSize,
+                  "8 byte common prefix expected");
+    assert(!IsEmpty());
+    assert(&this->session_etc64_ == static_cast<const void *>(this));
+
+    return Slice(reinterpret_cast<const char *>(this), kCommonPrefixSize);
+  }
+
+  // For any max_offset <= this value, the same encoding scheme is guaranteed.
+  static constexpr uint64_t kMaxOffsetStandardEncoding = 0xffffffffffU;
+
+ private:
+#ifndef NDEBUG
+  uint64_t max_offset_ = 0;
+#endif
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,183 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+#include "cache/cache_reservation_manager.h"
+
+#include <cassert>
+#include <cstddef>
+#include <cstring>
+#include <memory>
+
+#include "cache/cache_entry_roles.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/status.h"
+#include "table/block_based/reader_common.h"
+#include "util/coding.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+template <CacheEntryRole R>
+CacheReservationManagerImpl<R>::CacheReservationHandle::CacheReservationHandle(
+    std::size_t incremental_memory_used,
+    std::shared_ptr<CacheReservationManagerImpl> cache_res_mgr)
+    : incremental_memory_used_(incremental_memory_used) {
+  assert(cache_res_mgr);
+  cache_res_mgr_ = cache_res_mgr;
+}
+
+template <CacheEntryRole R>
+CacheReservationManagerImpl<
+    R>::CacheReservationHandle::~CacheReservationHandle() {
+  Status s = cache_res_mgr_->ReleaseCacheReservation(incremental_memory_used_);
+  s.PermitUncheckedError();
+}
+
+template <CacheEntryRole R>
+CacheReservationManagerImpl<R>::CacheReservationManagerImpl(
+    std::shared_ptr<Cache> cache, bool delayed_decrease)
+    : delayed_decrease_(delayed_decrease),
+      cache_allocated_size_(0),
+      memory_used_(0) {
+  assert(cache != nullptr);
+  cache_ = cache;
+}
+
+template <CacheEntryRole R>
+CacheReservationManagerImpl<R>::~CacheReservationManagerImpl() {
+  for (auto* handle : dummy_handles_) {
+    cache_->Release(handle, true);
+  }
+}
+
+template <CacheEntryRole R>
+Status CacheReservationManagerImpl<R>::UpdateCacheReservation(
+    std::size_t new_mem_used) {
+  memory_used_ = new_mem_used;
+  std::size_t cur_cache_allocated_size =
+      cache_allocated_size_.load(std::memory_order_relaxed);
+  if (new_mem_used == cur_cache_allocated_size) {
+    return Status::OK();
+  } else if (new_mem_used > cur_cache_allocated_size) {
+    Status s = IncreaseCacheReservation(new_mem_used);
+    return s;
+  } else {
+    // In delayed decrease mode, we don't decrease cache reservation
+    // untill the memory usage is less than 3/4 of what we reserve
+    // in the cache.
+    // We do this because
+    // (1) Dummy entry insertion is expensive in block cache
+    // (2) Delayed releasing previously inserted dummy entries can save such
+    // expensive dummy entry insertion on memory increase in the near future,
+    // which is likely to happen when the memory usage is greater than or equal
+    // to 3/4 of what we reserve
+    if (delayed_decrease_ && new_mem_used >= cur_cache_allocated_size / 4 * 3) {
+      return Status::OK();
+    } else {
+      Status s = DecreaseCacheReservation(new_mem_used);
+      return s;
+    }
+  }
+}
+
+template <CacheEntryRole R>
+Status CacheReservationManagerImpl<R>::MakeCacheReservation(
+    std::size_t incremental_memory_used,
+    std::unique_ptr<CacheReservationManager::CacheReservationHandle>* handle) {
+  assert(handle);
+  Status s =
+      UpdateCacheReservation(GetTotalMemoryUsed() + incremental_memory_used);
+  (*handle).reset(new CacheReservationManagerImpl::CacheReservationHandle(
+      incremental_memory_used,
+      std::enable_shared_from_this<
+          CacheReservationManagerImpl<R>>::shared_from_this()));
+  return s;
+}
+
+template <CacheEntryRole R>
+Status CacheReservationManagerImpl<R>::ReleaseCacheReservation(
+    std::size_t incremental_memory_used) {
+  assert(GetTotalMemoryUsed() >= incremental_memory_used);
+  std::size_t updated_total_mem_used =
+      GetTotalMemoryUsed() - incremental_memory_used;
+  Status s = UpdateCacheReservation(updated_total_mem_used);
+  return s;
+}
+
+template <CacheEntryRole R>
+Status CacheReservationManagerImpl<R>::IncreaseCacheReservation(
+    std::size_t new_mem_used) {
+  Status return_status = Status::OK();
+  while (new_mem_used > cache_allocated_size_.load(std::memory_order_relaxed)) {
+    Cache::Handle* handle = nullptr;
+    return_status = cache_->Insert(GetNextCacheKey(), nullptr, kSizeDummyEntry,
+                                   GetNoopDeleterForRole<R>(), &handle);
+
+    if (return_status != Status::OK()) {
+      return return_status;
+    }
+
+    dummy_handles_.push_back(handle);
+    cache_allocated_size_ += kSizeDummyEntry;
+  }
+  return return_status;
+}
+
+template <CacheEntryRole R>
+Status CacheReservationManagerImpl<R>::DecreaseCacheReservation(
+    std::size_t new_mem_used) {
+  Status return_status = Status::OK();
+
+  // Decrease to the smallest multiple of kSizeDummyEntry that is greater than
+  // or equal to new_mem_used We do addition instead of new_mem_used <=
+  // cache_allocated_size_.load(std::memory_order_relaxed) - kSizeDummyEntry to
+  // avoid underflow of size_t when cache_allocated_size_ = 0
+  while (new_mem_used + kSizeDummyEntry <=
+         cache_allocated_size_.load(std::memory_order_relaxed)) {
+    assert(!dummy_handles_.empty());
+    auto* handle = dummy_handles_.back();
+    cache_->Release(handle, true);
+    dummy_handles_.pop_back();
+    cache_allocated_size_ -= kSizeDummyEntry;
+  }
+  return return_status;
+}
+
+template <CacheEntryRole R>
+std::size_t CacheReservationManagerImpl<R>::GetTotalReservedCacheSize() {
+  return cache_allocated_size_.load(std::memory_order_relaxed);
+}
+
+template <CacheEntryRole R>
+std::size_t CacheReservationManagerImpl<R>::GetTotalMemoryUsed() {
+  return memory_used_;
+}
+
+template <CacheEntryRole R>
+Slice CacheReservationManagerImpl<R>::GetNextCacheKey() {
+  // Calling this function will have the side-effect of changing the
+  // underlying cache_key_ that is shared among other keys generated from this
+  // fucntion. Therefore please make sure the previous keys are saved/copied
+  // before calling this function.
+  cache_key_ = CacheKey::CreateUniqueForCacheLifetime(cache_.get());
+  return cache_key_.AsSlice();
+}
+
+template <CacheEntryRole R>
+Cache::DeleterFn CacheReservationManagerImpl<R>::TEST_GetNoopDeleterForRole() {
+  return GetNoopDeleterForRole<R>();
+}
+
+template class CacheReservationManagerImpl<
+    CacheEntryRole::kBlockBasedTableReader>;
+template class CacheReservationManagerImpl<
+    CacheEntryRole::kCompressionDictionaryBuildingBuffer>;
+template class CacheReservationManagerImpl<CacheEntryRole::kFilterConstruction>;
+template class CacheReservationManagerImpl<CacheEntryRole::kMisc>;
+template class CacheReservationManagerImpl<CacheEntryRole::kWriteBuffer>;
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,288 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#pragma once
+
+#include <atomic>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <mutex>
+#include <vector>
+
+#include "cache/cache_entry_roles.h"
+#include "cache/cache_key.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/status.h"
+#include "util/coding.h"
+
+namespace ROCKSDB_NAMESPACE {
+// CacheReservationManager is an interface for reserving cache space for the
+// memory used
+class CacheReservationManager {
+ public:
+  // CacheReservationHandle is for managing the lifetime of a cache reservation
+  // for an incremental amount of memory used (i.e, incremental_memory_used)
+  class CacheReservationHandle {
+   public:
+    virtual ~CacheReservationHandle() {}
+  };
+  virtual ~CacheReservationManager() {}
+  virtual Status UpdateCacheReservation(std::size_t new_memory_used) = 0;
+  virtual Status MakeCacheReservation(
+      std::size_t incremental_memory_used,
+      std::unique_ptr<CacheReservationManager::CacheReservationHandle>
+          *handle) = 0;
+  virtual std::size_t GetTotalReservedCacheSize() = 0;
+  virtual std::size_t GetTotalMemoryUsed() = 0;
+};
+
+// CacheReservationManagerImpl implements interface CacheReservationManager
+// for reserving cache space for the memory used by inserting/releasing dummy
+// entries in the cache.
+//
+// This class is NOT thread-safe, except that GetTotalReservedCacheSize()
+// can be called without external synchronization.
+template <CacheEntryRole R>
+class CacheReservationManagerImpl
+    : public CacheReservationManager,
+      public std::enable_shared_from_this<CacheReservationManagerImpl<R>> {
+ public:
+  class CacheReservationHandle
+      : public CacheReservationManager::CacheReservationHandle {
+   public:
+    CacheReservationHandle(
+        std::size_t incremental_memory_used,
+        std::shared_ptr<CacheReservationManagerImpl> cache_res_mgr);
+    ~CacheReservationHandle() override;
+
+   private:
+    std::size_t incremental_memory_used_;
+    std::shared_ptr<CacheReservationManagerImpl> cache_res_mgr_;
+  };
+
+  // Construct a CacheReservationManagerImpl
+  // @param cache The cache where dummy entries are inserted and released for
+  // reserving cache space
+  // @param delayed_decrease If set true, then dummy entries won't be released
+  //                         immediately when memory usage decreases.
+  //                         Instead, it will be released when the memory usage
+  //                         decreases to 3/4 of what we have reserved so far.
+  //                         This is for saving some future dummy entry
+  //                         insertion when memory usage increases are likely to
+  //                         happen in the near future.
+  //
+  // REQUIRED: cache is not nullptr
+  explicit CacheReservationManagerImpl(std::shared_ptr<Cache> cache,
+                                       bool delayed_decrease = false);
+
+  // no copy constructor, copy assignment, move constructor, move assignment
+  CacheReservationManagerImpl(const CacheReservationManagerImpl &) = delete;
+  CacheReservationManagerImpl &operator=(const CacheReservationManagerImpl &) =
+      delete;
+  CacheReservationManagerImpl(CacheReservationManagerImpl &&) = delete;
+  CacheReservationManagerImpl &operator=(CacheReservationManagerImpl &&) =
+      delete;
+
+  ~CacheReservationManagerImpl() override;
+
+  // One of the two ways of reserving/releasing cache space,
+  // see MakeCacheReservation() for the other.
+  //
+  // Use ONLY one of these two ways to prevent unexpected behavior.
+  //
+  // Insert and release dummy entries in the cache to
+  // match the size of total dummy entries with the least multiple of
+  // kSizeDummyEntry greater than or equal to new_mem_used
+  //
+  // Insert dummy entries if new_memory_used > cache_allocated_size_;
+  //
+  // Release dummy entries if new_memory_used < cache_allocated_size_
+  // (and new_memory_used < cache_allocated_size_ * 3/4
+  // when delayed_decrease is set true);
+  //
+  // Keey dummy entries the same if (1) new_memory_used == cache_allocated_size_
+  // or (2) new_memory_used is in the interval of
+  // [cache_allocated_size_ * 3/4, cache_allocated_size) when delayed_decrease
+  // is set true.
+  //
+  // @param new_memory_used The number of bytes used by new memory
+  //        The most recent new_memoy_used passed in will be returned
+  //        in GetTotalMemoryUsed() even when the call return non-ok status.
+  //
+  //        Since the class is NOT thread-safe, external synchronization on the
+  //        order of calling UpdateCacheReservation() is needed if you want
+  //        GetTotalMemoryUsed() indeed returns the latest memory used.
+  //
+  // @return On inserting dummy entries, it returns Status::OK() if all dummy
+  //         entry insertions succeed.
+  //         Otherwise, it returns the first non-ok status;
+  //         On releasing dummy entries, it always returns Status::OK().
+  //         On keeping dummy entries the same, it always returns Status::OK().
+  Status UpdateCacheReservation(std::size_t new_memory_used) override;
+
+  // One of the two ways of reserving cache space and releasing is done through
+  // destruction of CacheReservationHandle.
+  // See UpdateCacheReservation() for the other way.
+  //
+  // Use ONLY one of these two ways to prevent unexpected behavior.
+  //
+  // Insert dummy entries in the cache for the incremental memory usage
+  // to match the size of total dummy entries with the least multiple of
+  // kSizeDummyEntry greater than or equal to the total memory used.
+  //
+  // A CacheReservationHandle is returned as an output parameter.
+  // The reserved dummy entries are automatically released on the destruction of
+  // this handle, which achieves better RAII per cache reservation.
+  //
+  // WARNING: Deallocate all the handles of the CacheReservationManager object
+  //          before deallocating the object to prevent unexpected behavior.
+  //
+  // @param incremental_memory_used The number of bytes increased in memory
+  //        usage.
+  //
+  //        Calling GetTotalMemoryUsed() afterward will return the total memory
+  //        increased by this number, even when calling MakeCacheReservation()
+  //        returns non-ok status.
+  //
+  //        Since the class is NOT thread-safe, external synchronization in
+  //        calling MakeCacheReservation() is needed if you want
+  //        GetTotalMemoryUsed() indeed returns the latest memory used.
+  //
+  // @param handle An pointer to std::unique_ptr<CacheReservationHandle> that
+  //        manages the lifetime of the cache reservation represented by the
+  //        handle.
+  //
+  // @return It returns Status::OK() if all dummy
+  //         entry insertions succeed.
+  //         Otherwise, it returns the first non-ok status;
+  //
+  // REQUIRES: handle != nullptr
+  Status MakeCacheReservation(
+      std::size_t incremental_memory_used,
+      std::unique_ptr<CacheReservationManager::CacheReservationHandle> *handle)
+      override;
+
+  // Return the size of the cache (which is a multiple of kSizeDummyEntry)
+  // successfully reserved by calling UpdateCacheReservation().
+  //
+  // When UpdateCacheReservation() returns non-ok status,
+  // calling GetTotalReservedCacheSize() after that might return a slightly
+  // smaller number than the actual reserved cache size due to
+  // the returned number will always be a multiple of kSizeDummyEntry
+  // and cache full might happen in the middle of inserting a dummy entry.
+  std::size_t GetTotalReservedCacheSize() override;
+
+  // Return the latest total memory used indicated by the most recent call of
+  // UpdateCacheReservation(std::size_t new_memory_used);
+  std::size_t GetTotalMemoryUsed() override;
+
+  static constexpr std::size_t GetDummyEntrySize() { return kSizeDummyEntry; }
+
+  // For testing only - it is to help ensure the NoopDeleterForRole<R>
+  // accessed from CacheReservationManagerImpl and the one accessed from the
+  // test are from the same translation units
+  static Cache::DeleterFn TEST_GetNoopDeleterForRole();
+
+ private:
+  static constexpr std::size_t kSizeDummyEntry = 256 * 1024;
+
+  Slice GetNextCacheKey();
+
+  Status ReleaseCacheReservation(std::size_t incremental_memory_used);
+  Status IncreaseCacheReservation(std::size_t new_mem_used);
+  Status DecreaseCacheReservation(std::size_t new_mem_used);
+
+  std::shared_ptr<Cache> cache_;
+  bool delayed_decrease_;
+  std::atomic<std::size_t> cache_allocated_size_;
+  std::size_t memory_used_;
+  std::vector<Cache::Handle *> dummy_handles_;
+  CacheKey cache_key_;
+};
+
+class ConcurrentCacheReservationManager
+    : public CacheReservationManager,
+      public std::enable_shared_from_this<ConcurrentCacheReservationManager> {
+ public:
+  class CacheReservationHandle
+      : public CacheReservationManager::CacheReservationHandle {
+   public:
+    CacheReservationHandle(
+        std::shared_ptr<ConcurrentCacheReservationManager> cache_res_mgr,
+        std::unique_ptr<CacheReservationManager::CacheReservationHandle>
+            cache_res_handle) {
+      assert(cache_res_mgr && cache_res_handle);
+      cache_res_mgr_ = cache_res_mgr;
+      cache_res_handle_ = std::move(cache_res_handle);
+    }
+
+    ~CacheReservationHandle() override {
+      std::lock_guard<std::mutex> lock(cache_res_mgr_->cache_res_mgr_mu_);
+      cache_res_handle_.reset();
+    }
+
+   private:
+    std::shared_ptr<ConcurrentCacheReservationManager> cache_res_mgr_;
+    std::unique_ptr<CacheReservationManager::CacheReservationHandle>
+        cache_res_handle_;
+  };
+
+  explicit ConcurrentCacheReservationManager(
+      std::shared_ptr<CacheReservationManager> cache_res_mgr) {
+    cache_res_mgr_ = std::move(cache_res_mgr);
+  }
+  ConcurrentCacheReservationManager(const ConcurrentCacheReservationManager &) =
+      delete;
+  ConcurrentCacheReservationManager &operator=(
+      const ConcurrentCacheReservationManager &) = delete;
+  ConcurrentCacheReservationManager(ConcurrentCacheReservationManager &&) =
+      delete;
+  ConcurrentCacheReservationManager &operator=(
+      ConcurrentCacheReservationManager &&) = delete;
+
+  ~ConcurrentCacheReservationManager() override {}
+
+  inline Status UpdateCacheReservation(std::size_t new_memory_used) override {
+    std::lock_guard<std::mutex> lock(cache_res_mgr_mu_);
+    return cache_res_mgr_->UpdateCacheReservation(new_memory_used);
+  }
+  inline Status MakeCacheReservation(
+      std::size_t incremental_memory_used,
+      std::unique_ptr<CacheReservationManager::CacheReservationHandle> *handle)
+      override {
+    std::unique_ptr<CacheReservationManager::CacheReservationHandle>
+        wrapped_handle;
+    Status s;
+    {
+      std::lock_guard<std::mutex> lock(cache_res_mgr_mu_);
+      s = cache_res_mgr_->MakeCacheReservation(incremental_memory_used,
+                                               &wrapped_handle);
+    }
+    (*handle).reset(
+        new ConcurrentCacheReservationManager::CacheReservationHandle(
+            std::enable_shared_from_this<
+                ConcurrentCacheReservationManager>::shared_from_this(),
+            std::move(wrapped_handle)));
+    return s;
+  }
+  inline std::size_t GetTotalReservedCacheSize() override {
+    return cache_res_mgr_->GetTotalReservedCacheSize();
+  }
+  inline std::size_t GetTotalMemoryUsed() override {
+    std::lock_guard<std::mutex> lock(cache_res_mgr_mu_);
+    return cache_res_mgr_->GetTotalMemoryUsed();
+  }
+
+ private:
+  std::mutex cache_res_mgr_mu_;
+  std::shared_ptr<CacheReservationManager> cache_res_mgr_;
+};
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,467 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+#include "cache/cache_reservation_manager.h"
+
+#include <cstddef>
+#include <cstring>
+#include <memory>
+
+#include "cache/cache_entry_roles.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/slice.h"
+#include "test_util/testharness.h"
+#include "util/coding.h"
+
+namespace ROCKSDB_NAMESPACE {
+class CacheReservationManagerTest : public ::testing::Test {
+ protected:
+  static constexpr std::size_t kSizeDummyEntry =
+      CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
+  static constexpr std::size_t kCacheCapacity = 4096 * kSizeDummyEntry;
+  static constexpr int kNumShardBits = 0;  // 2^0 shard
+  static constexpr std::size_t kMetaDataChargeOverhead = 10000;
+
+  std::shared_ptr<Cache> cache = NewLRUCache(kCacheCapacity, kNumShardBits);
+  std::shared_ptr<CacheReservationManager> test_cache_rev_mng;
+
+  CacheReservationManagerTest() {
+    test_cache_rev_mng =
+        std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
+            cache);
+  }
+};
+
+TEST_F(CacheReservationManagerTest, GenerateCacheKey) {
+  std::size_t new_mem_used = 1 * kSizeDummyEntry;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry);
+  ASSERT_LT(cache->GetPinnedUsage(),
+            1 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  // Next unique Cache key
+  CacheKey ckey = CacheKey::CreateUniqueForCacheLifetime(cache.get());
+  // Back it up to the one used by CRM (using CacheKey implementation details)
+  using PairU64 = std::pair<uint64_t, uint64_t>;
+  auto& ckey_pair = *reinterpret_cast<PairU64*>(&ckey);
+  ckey_pair.second--;
+
+  // Specific key (subject to implementation details)
+  EXPECT_EQ(ckey_pair, PairU64(0, 2));
+
+  Cache::Handle* handle = cache->Lookup(ckey.AsSlice());
+  EXPECT_NE(handle, nullptr)
+      << "Failed to generate the cache key for the dummy entry correctly";
+  // Clean up the returned handle from Lookup() to prevent memory leak
+  cache->Release(handle);
+}
+
+TEST_F(CacheReservationManagerTest, KeepCacheReservationTheSame) {
+  std::size_t new_mem_used = 1 * kSizeDummyEntry;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry);
+  ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
+  std::size_t initial_pinned_usage = cache->GetPinnedUsage();
+  ASSERT_GE(initial_pinned_usage, 1 * kSizeDummyEntry);
+  ASSERT_LT(initial_pinned_usage,
+            1 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to keep cache reservation the same when new_mem_used equals "
+         "to current cache reservation";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry)
+      << "Failed to bookkeep correctly when new_mem_used equals to current "
+         "cache reservation";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly when new_mem_used "
+         "equals to current cache reservation";
+  EXPECT_EQ(cache->GetPinnedUsage(), initial_pinned_usage)
+      << "Failed to keep underlying dummy entries the same when new_mem_used "
+         "equals to current cache reservation";
+}
+
+TEST_F(CacheReservationManagerTest,
+       IncreaseCacheReservationByMultiplesOfDummyEntrySize) {
+  std::size_t new_mem_used = 2 * kSizeDummyEntry;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to increase cache reservation correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            2 * kSizeDummyEntry)
+      << "Failed to bookkeep cache reservation increase correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry)
+      << "Failed to increase underlying dummy entries in cache correctly";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            2 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to increase underlying dummy entries in cache correctly";
+}
+
+TEST_F(CacheReservationManagerTest,
+       IncreaseCacheReservationNotByMultiplesOfDummyEntrySize) {
+  std::size_t new_mem_used = 2 * kSizeDummyEntry + kSizeDummyEntry / 2;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to increase cache reservation correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            3 * kSizeDummyEntry)
+      << "Failed to bookkeep cache reservation increase correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 3 * kSizeDummyEntry)
+      << "Failed to increase underlying dummy entries in cache correctly";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            3 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to increase underlying dummy entries in cache correctly";
+}
+
+TEST(CacheReservationManagerIncreaseReservcationOnFullCacheTest,
+     IncreaseCacheReservationOnFullCache) {
+  ;
+  constexpr std::size_t kSizeDummyEntry =
+      CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
+  constexpr std::size_t kSmallCacheCapacity = 4 * kSizeDummyEntry;
+  constexpr std::size_t kBigCacheCapacity = 4096 * kSizeDummyEntry;
+  constexpr std::size_t kMetaDataChargeOverhead = 10000;
+
+  LRUCacheOptions lo;
+  lo.capacity = kSmallCacheCapacity;
+  lo.num_shard_bits = 0;  // 2^0 shard
+  lo.strict_capacity_limit = true;
+  std::shared_ptr<Cache> cache = NewLRUCache(lo);
+  std::shared_ptr<CacheReservationManager> test_cache_rev_mng =
+      std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
+          cache);
+
+  std::size_t new_mem_used = kSmallCacheCapacity + 1;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::Incomplete())
+      << "Failed to return status to indicate failure of dummy entry insertion "
+         "during cache reservation on full cache";
+  EXPECT_GE(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry)
+      << "Failed to bookkeep correctly before cache resevation failure happens "
+         "due to full cache";
+  EXPECT_LE(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            kSmallCacheCapacity)
+      << "Failed to bookkeep correctly (i.e, bookkeep only successful dummy "
+         "entry insertions) when encountering cache resevation failure due to "
+         "full cache";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
+      << "Failed to insert underlying dummy entries correctly when "
+         "encountering cache resevation failure due to full cache";
+  EXPECT_LE(cache->GetPinnedUsage(), kSmallCacheCapacity)
+      << "Failed to insert underlying dummy entries correctly when "
+         "encountering cache resevation failure due to full cache";
+
+  new_mem_used = kSmallCacheCapacity / 2;  // 2 dummy entries
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to decrease cache reservation after encountering cache "
+         "reservation failure due to full cache";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            2 * kSizeDummyEntry)
+      << "Failed to bookkeep cache reservation decrease correctly after "
+         "encountering cache reservation due to full cache";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry)
+      << "Failed to release underlying dummy entries correctly on cache "
+         "reservation decrease after encountering cache resevation failure due "
+         "to full cache";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            2 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to release underlying dummy entries correctly on cache "
+         "reservation decrease after encountering cache resevation failure due "
+         "to full cache";
+
+  // Create cache full again for subsequent tests
+  new_mem_used = kSmallCacheCapacity + 1;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::Incomplete())
+      << "Failed to return status to indicate failure of dummy entry insertion "
+         "during cache reservation on full cache";
+  EXPECT_GE(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry)
+      << "Failed to bookkeep correctly before cache resevation failure happens "
+         "due to full cache";
+  EXPECT_LE(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            kSmallCacheCapacity)
+      << "Failed to bookkeep correctly (i.e, bookkeep only successful dummy "
+         "entry insertions) when encountering cache resevation failure due to "
+         "full cache";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
+      << "Failed to insert underlying dummy entries correctly when "
+         "encountering cache resevation failure due to full cache";
+  EXPECT_LE(cache->GetPinnedUsage(), kSmallCacheCapacity)
+      << "Failed to insert underlying dummy entries correctly when "
+         "encountering cache resevation failure due to full cache";
+
+  // Increase cache capacity so the previously failed insertion can fully
+  // succeed
+  cache->SetCapacity(kBigCacheCapacity);
+  new_mem_used = kSmallCacheCapacity + 1;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to increase cache reservation after increasing cache capacity "
+         "and mitigating cache full error";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            5 * kSizeDummyEntry)
+      << "Failed to bookkeep cache reservation increase correctly after "
+         "increasing cache capacity and mitigating cache full error";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 5 * kSizeDummyEntry)
+      << "Failed to insert underlying dummy entries correctly after increasing "
+         "cache capacity and mitigating cache full error";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            5 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to insert underlying dummy entries correctly after increasing "
+         "cache capacity and mitigating cache full error";
+}
+
+TEST_F(CacheReservationManagerTest,
+       DecreaseCacheReservationByMultiplesOfDummyEntrySize) {
+  std::size_t new_mem_used = 2 * kSizeDummyEntry;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            2 * kSizeDummyEntry);
+  ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
+  ASSERT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry);
+  ASSERT_LT(cache->GetPinnedUsage(),
+            2 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  new_mem_used = 1 * kSizeDummyEntry;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to decrease cache reservation correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry)
+      << "Failed to bookkeep cache reservation decrease correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
+      << "Failed to decrease underlying dummy entries in cache correctly";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            1 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to decrease underlying dummy entries in cache correctly";
+}
+
+TEST_F(CacheReservationManagerTest,
+       DecreaseCacheReservationNotByMultiplesOfDummyEntrySize) {
+  std::size_t new_mem_used = 2 * kSizeDummyEntry;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            2 * kSizeDummyEntry);
+  ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
+  ASSERT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry);
+  ASSERT_LT(cache->GetPinnedUsage(),
+            2 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  new_mem_used = kSizeDummyEntry / 2;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to decrease cache reservation correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry)
+      << "Failed to bookkeep cache reservation decrease correctly";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
+      << "Failed to decrease underlying dummy entries in cache correctly";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            1 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to decrease underlying dummy entries in cache correctly";
+}
+
+TEST(CacheReservationManagerWithDelayedDecreaseTest,
+     DecreaseCacheReservationWithDelayedDecrease) {
+  constexpr std::size_t kSizeDummyEntry =
+      CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
+  constexpr std::size_t kCacheCapacity = 4096 * kSizeDummyEntry;
+  constexpr std::size_t kMetaDataChargeOverhead = 10000;
+
+  LRUCacheOptions lo;
+  lo.capacity = kCacheCapacity;
+  lo.num_shard_bits = 0;
+  std::shared_ptr<Cache> cache = NewLRUCache(lo);
+  std::shared_ptr<CacheReservationManager> test_cache_rev_mng =
+      std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
+          cache, true /* delayed_decrease */);
+
+  std::size_t new_mem_used = 8 * kSizeDummyEntry;
+  Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            8 * kSizeDummyEntry);
+  ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
+  std::size_t initial_pinned_usage = cache->GetPinnedUsage();
+  ASSERT_GE(initial_pinned_usage, 8 * kSizeDummyEntry);
+  ASSERT_LT(initial_pinned_usage,
+            8 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  new_mem_used = 6 * kSizeDummyEntry;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK()) << "Failed to delay decreasing cache reservation";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            8 * kSizeDummyEntry)
+      << "Failed to bookkeep correctly when delaying cache reservation "
+         "decrease";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_EQ(cache->GetPinnedUsage(), initial_pinned_usage)
+      << "Failed to delay decreasing underlying dummy entries in cache";
+
+  new_mem_used = 7 * kSizeDummyEntry;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK()) << "Failed to delay decreasing cache reservation";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            8 * kSizeDummyEntry)
+      << "Failed to bookkeep correctly when delaying cache reservation "
+         "decrease";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_EQ(cache->GetPinnedUsage(), initial_pinned_usage)
+      << "Failed to delay decreasing underlying dummy entries in cache";
+
+  new_mem_used = 6 * kSizeDummyEntry - 1;
+  s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+  EXPECT_EQ(s, Status::OK())
+      << "Failed to decrease cache reservation correctly when new_mem_used < "
+         "GetTotalReservedCacheSize() * 3 / 4 on delayed decrease mode";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            6 * kSizeDummyEntry)
+      << "Failed to bookkeep correctly when new_mem_used < "
+         "GetTotalReservedCacheSize() * 3 / 4 on delayed decrease mode";
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
+      << "Failed to bookkeep the used memory correctly";
+  EXPECT_GE(cache->GetPinnedUsage(), 6 * kSizeDummyEntry)
+      << "Failed to decrease underlying dummy entries in cache when "
+         "new_mem_used < GetTotalReservedCacheSize() * 3 / 4 on delayed "
+         "decrease mode";
+  EXPECT_LT(cache->GetPinnedUsage(),
+            6 * kSizeDummyEntry + kMetaDataChargeOverhead)
+      << "Failed to decrease underlying dummy entries in cache when "
+         "new_mem_used < GetTotalReservedCacheSize() * 3 / 4 on delayed "
+         "decrease mode";
+}
+
+TEST(CacheReservationManagerDestructorTest,
+     ReleaseRemainingDummyEntriesOnDestruction) {
+  constexpr std::size_t kSizeDummyEntry =
+      CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
+  constexpr std::size_t kCacheCapacity = 4096 * kSizeDummyEntry;
+  constexpr std::size_t kMetaDataChargeOverhead = 10000;
+
+  LRUCacheOptions lo;
+  lo.capacity = kCacheCapacity;
+  lo.num_shard_bits = 0;
+  std::shared_ptr<Cache> cache = NewLRUCache(lo);
+  {
+    std::shared_ptr<CacheReservationManager> test_cache_rev_mng =
+        std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
+            cache);
+    std::size_t new_mem_used = 1 * kSizeDummyEntry;
+    Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
+    ASSERT_EQ(s, Status::OK());
+    ASSERT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry);
+    ASSERT_LT(cache->GetPinnedUsage(),
+              1 * kSizeDummyEntry + kMetaDataChargeOverhead);
+  }
+  EXPECT_EQ(cache->GetPinnedUsage(), 0 * kSizeDummyEntry)
+      << "Failed to release remaining underlying dummy entries in cache in "
+         "CacheReservationManager's destructor";
+}
+
+TEST(CacheReservationHandleTest, HandleTest) {
+  constexpr std::size_t kOneGigabyte = 1024 * 1024 * 1024;
+  constexpr std::size_t kSizeDummyEntry = 256 * 1024;
+  constexpr std::size_t kMetaDataChargeOverhead = 10000;
+
+  LRUCacheOptions lo;
+  lo.capacity = kOneGigabyte;
+  lo.num_shard_bits = 0;
+  std::shared_ptr<Cache> cache = NewLRUCache(lo);
+
+  std::shared_ptr<CacheReservationManager> test_cache_rev_mng(
+      std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
+          cache));
+
+  std::size_t mem_used = 0;
+  const std::size_t incremental_mem_used_handle_1 = 1 * kSizeDummyEntry;
+  const std::size_t incremental_mem_used_handle_2 = 2 * kSizeDummyEntry;
+  std::unique_ptr<CacheReservationManager::CacheReservationHandle> handle_1,
+      handle_2;
+
+  // To test consecutive CacheReservationManager::MakeCacheReservation works
+  // correctly in terms of returning the handle as well as updating cache
+  // reservation and the latest total memory used
+  Status s = test_cache_rev_mng->MakeCacheReservation(
+      incremental_mem_used_handle_1, &handle_1);
+  mem_used = mem_used + incremental_mem_used_handle_1;
+  ASSERT_EQ(s, Status::OK());
+  EXPECT_TRUE(handle_1 != nullptr);
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(), mem_used);
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), mem_used);
+  EXPECT_GE(cache->GetPinnedUsage(), mem_used);
+  EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
+
+  s = test_cache_rev_mng->MakeCacheReservation(incremental_mem_used_handle_2,
+                                               &handle_2);
+  mem_used = mem_used + incremental_mem_used_handle_2;
+  ASSERT_EQ(s, Status::OK());
+  EXPECT_TRUE(handle_2 != nullptr);
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(), mem_used);
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), mem_used);
+  EXPECT_GE(cache->GetPinnedUsage(), mem_used);
+  EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
+
+  // To test
+  // CacheReservationManager::CacheReservationHandle::~CacheReservationHandle()
+  // works correctly in releasing the cache reserved for the handle
+  handle_1.reset();
+  EXPECT_TRUE(handle_1 == nullptr);
+  mem_used = mem_used - incremental_mem_used_handle_1;
+  EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(), mem_used);
+  EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), mem_used);
+  EXPECT_GE(cache->GetPinnedUsage(), mem_used);
+  EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
+
+  // To test the actual CacheReservationManager object won't be deallocated
+  // as long as there remain handles pointing to it.
+  // We strongly recommend deallocating CacheReservationManager object only
+  // after all its handles are deallocated to keep things easy to reasonate
+  test_cache_rev_mng.reset();
+  EXPECT_GE(cache->GetPinnedUsage(), mem_used);
+  EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
+
+  handle_2.reset();
+  // The CacheReservationManager object is now deallocated since all the handles
+  // and its original pointer is gone
+  mem_used = mem_used - incremental_mem_used_handle_2;
+  EXPECT_EQ(mem_used, 0);
+  EXPECT_EQ(cache->GetPinnedUsage(), mem_used);
+}
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -609,6 +609,9 @@ TEST_P(CacheTest, SetCapacity) {
  for (size_t i = 5; i < 10; i++) {
    cache->Release(handles[i]);
  }
+
+  // Make sure this doesn't crash or upset ASAN/valgrind
+  cache->DisownData();
 }

 TEST_P(LRUCacheTest, SetStrictCapacityLimit) {
@@ -712,25 +715,98 @@ TEST_P(CacheTest, OverCapacity) {
 }

 namespace {
-std::vector<std::pair<int, int>> callback_state;
-void callback(void* entry, size_t charge) {
-  callback_state.push_back({DecodeValue(entry), static_cast<int>(charge)});
+std::vector<std::pair<int, int>> legacy_callback_state;
+void legacy_callback(void* value, size_t charge) {
+  legacy_callback_state.push_back(
+      {DecodeValue(value), static_cast<int>(charge)});
 }
 };

-TEST_P(CacheTest, ApplyToAllCacheEntiresTest) {
+TEST_P(CacheTest, ApplyToAllCacheEntriesTest) {
  std::vector<std::pair<int, int>> inserted;
-  callback_state.clear();
+  legacy_callback_state.clear();

  for (int i = 0; i < 10; ++i) {
    Insert(i, i * 2, i + 1);
    inserted.push_back({i * 2, i + 1});
  }
-  cache_->ApplyToAllCacheEntries(callback, true);
+  cache_->ApplyToAllCacheEntries(legacy_callback, true);
+
+  std::sort(inserted.begin(), inserted.end());
+  std::sort(legacy_callback_state.begin(), legacy_callback_state.end());
+  ASSERT_EQ(inserted.size(), legacy_callback_state.size());
+  for (size_t i = 0; i < inserted.size(); ++i) {
+    EXPECT_EQ(inserted[i], legacy_callback_state[i]);
+  }
+}
+
+TEST_P(CacheTest, ApplyToAllEntriesTest) {
+  std::vector<std::string> callback_state;
+  const auto callback = [&](const Slice& key, void* value, size_t charge,
+                            Cache::DeleterFn deleter) {
+    callback_state.push_back(ToString(DecodeKey(key)) + "," +
+                             ToString(DecodeValue(value)) + "," +
+                             ToString(charge));
+    assert(deleter == &CacheTest::Deleter);
+  };
+
+  std::vector<std::string> inserted;
+  callback_state.clear();
+
+  for (int i = 0; i < 10; ++i) {
+    Insert(i, i * 2, i + 1);
+    inserted.push_back(ToString(i) + "," + ToString(i * 2) + "," +
+                       ToString(i + 1));
+  }
+  cache_->ApplyToAllEntries(callback, /*opts*/ {});

  std::sort(inserted.begin(), inserted.end());
  std::sort(callback_state.begin(), callback_state.end());
-  ASSERT_TRUE(inserted == callback_state);
+  ASSERT_EQ(inserted.size(), callback_state.size());
+  for (size_t i = 0; i < inserted.size(); ++i) {
+    EXPECT_EQ(inserted[i], callback_state[i]);
+  }
+}
+
+TEST_P(CacheTest, ApplyToAllEntriesDuringResize) {
+  // This is a mini-stress test of ApplyToAllEntries, to ensure
+  // items in the cache that are neither added nor removed
+  // during ApplyToAllEntries are counted exactly once.
+
+  // Insert some entries that we expect to be seen exactly once
+  // during iteration.
+  constexpr int kSpecialCharge = 2;
+  constexpr int kNotSpecialCharge = 1;
+  constexpr int kSpecialCount = 100;
+  for (int i = 0; i < kSpecialCount; ++i) {
+    Insert(i, i * 2, kSpecialCharge);
+  }
+
+  // For callback
+  int special_count = 0;
+  const auto callback = [&](const Slice&, void*, size_t charge,
+                            Cache::DeleterFn) {
+    if (charge == static_cast<size_t>(kSpecialCharge)) {
+      ++special_count;
+    }
+  };
+
+  // Start counting
+  std::thread apply_thread([&]() {
+    // Use small average_entries_per_lock to make the problem difficult
+    Cache::ApplyToAllEntriesOptions opts;
+    opts.average_entries_per_lock = 2;
+    cache_->ApplyToAllEntries(callback, opts);
+  });
+
+  // In parallel, add more entries, enough to cause resize but not enough
+  // to cause ejections
+  for (int i = kSpecialCount * 1; i < kSpecialCount * 6; ++i) {
+    Insert(i, i * 2, kNotSpecialCharge);
+  }
+
+  apply_thread.join();
+  ASSERT_EQ(special_count, kSpecialCount);
 }

 TEST_P(CacheTest, DefaultShardBits) {
@@ -749,11 +825,12 @@ TEST_P(CacheTest, DefaultShardBits) {
  ASSERT_EQ(6, sc->GetNumShardBits());
 }

-TEST_P(CacheTest, GetCharge) {
+TEST_P(CacheTest, GetChargeAndDeleter) {
  Insert(1, 2);
  Cache::Handle* h1 = cache_->Lookup(EncodeKey(1));
  ASSERT_EQ(2, DecodeValue(cache_->Value(h1)));
  ASSERT_EQ(1, cache_->GetCharge(h1));
+  ASSERT_EQ(&CacheTest::Deleter, cache_->GetDeleter(h1));
  cache_->Release(h1);
 }

@@ -33,11 +33,11 @@ std::shared_ptr<Cache> NewClockCache(
 #ifndef ROCKSDB_USE_RTTI
 #define TBB_USE_EXCEPTIONS 0
 #endif
-#include "tbb/concurrent_hash_map.h"
-
 #include "cache/sharded_cache.h"
+#include "port/lang.h"
 #include "port/malloc.h"
 #include "port/port.h"
+#include "tbb/concurrent_hash_map.h"
 #include "util/autovector.h"
 #include "util/mutexlock.h"

@@ -176,10 +176,13 @@ namespace {
 // Cache entry meta data.
 struct CacheHandle {
  Slice key;
-  uint32_t hash;
  void* value;
  size_t charge;
-  void (*deleter)(const Slice&, void* value);
+  Cache::DeleterFn deleter;
+  uint32_t hash;
+
+  // Addition to "charge" to get "total charge" under metadata policy.
+  uint32_t meta_charge;

  // Flags and counters associated with the cache handle:
  //   lowest bit: in-cache bit
@@ -205,9 +208,8 @@ struct CacheHandle {
    return *this;
  }

-  inline static size_t CalcTotalCharge(
-      Slice key, size_t charge,
-      CacheMetadataChargePolicy metadata_charge_policy) {
+  inline static uint32_t CalcMetadataCharge(
+      Slice key, CacheMetadataChargePolicy metadata_charge_policy) {
    size_t meta_charge = 0;
    if (metadata_charge_policy == kFullChargeCacheMetadata) {
      meta_charge += sizeof(CacheHandle);
@@ -218,32 +220,30 @@ struct CacheHandle {
      meta_charge += key.size();
 #endif
    }
-    return charge + meta_charge;
+    assert(meta_charge <= UINT32_MAX);
+    return static_cast<uint32_t>(meta_charge);
  }

-  inline size_t CalcTotalCharge(
-      CacheMetadataChargePolicy metadata_charge_policy) {
-    return CalcTotalCharge(key, charge, metadata_charge_policy);
-  }
+  inline size_t GetTotalCharge() { return charge + meta_charge; }
 };

 // Key of hash map. We store hash value with the key for convenience.
-struct CacheKey {
+struct ClockCacheKey {
  Slice key;
  uint32_t hash_value;

-  CacheKey() = default;
+  ClockCacheKey() = default;

-  CacheKey(const Slice& k, uint32_t h) {
+  ClockCacheKey(const Slice& k, uint32_t h) {
    key = k;
    hash_value = h;
  }

-  static bool equal(const CacheKey& a, const CacheKey& b) {
+  static bool equal(const ClockCacheKey& a, const ClockCacheKey& b) {
    return a.hash_value == b.hash_value && a.key == b.key;
  }

-  static size_t hash(const CacheKey& a) {
+  static size_t hash(const ClockCacheKey& a) {
    return static_cast<size_t>(a.hash_value);
  }
 };
@@ -260,7 +260,8 @@ struct CleanupContext {
 class ClockCacheShard final : public CacheShard {
 public:
  // Hash map type.
-  typedef tbb::concurrent_hash_map<CacheKey, CacheHandle*, CacheKey> HashTable;
+  using HashTable =
+      tbb::concurrent_hash_map<ClockCacheKey, CacheHandle*, ClockCacheKey>;

  ClockCacheShard();
  ~ClockCacheShard() override;
@@ -271,21 +272,42 @@ class ClockCacheShard final : public CacheShard {
  Status Insert(const Slice& key, uint32_t hash, void* value, size_t charge,
                void (*deleter)(const Slice& key, void* value),
                Cache::Handle** handle, Cache::Priority priority) override;
+  Status Insert(const Slice& key, uint32_t hash, void* value,
+                const Cache::CacheItemHelper* helper, size_t charge,
+                Cache::Handle** handle, Cache::Priority priority) override {
+    return Insert(key, hash, value, charge, helper->del_cb, handle, priority);
+  }
  Cache::Handle* Lookup(const Slice& key, uint32_t hash) override;
+  Cache::Handle* Lookup(const Slice& key, uint32_t hash,
+                        const Cache::CacheItemHelper* /*helper*/,
+                        const Cache::CreateCallback& /*create_cb*/,
+                        Cache::Priority /*priority*/, bool /*wait*/,
+                        Statistics* /*stats*/) override {
+    return Lookup(key, hash);
+  }
+  bool Release(Cache::Handle* handle, bool /*useful*/,
+               bool erase_if_last_ref) override {
+    return Release(handle, erase_if_last_ref);
+  }
+  bool IsReady(Cache::Handle* /*handle*/) override { return true; }
+  void Wait(Cache::Handle* /*handle*/) override {}
+
  // If the entry in in cache, increase reference count and return true.
  // Return false otherwise.
  //
  // Not necessary to hold mutex_ before being called.
  bool Ref(Cache::Handle* handle) override;
-  bool Release(Cache::Handle* handle, bool force_erase = false) override;
+  bool Release(Cache::Handle* handle, bool erase_if_last_ref = false) override;
  void Erase(const Slice& key, uint32_t hash) override;
  bool EraseAndConfirm(const Slice& key, uint32_t hash,
                       CleanupContext* context);
  size_t GetUsage() const override;
  size_t GetPinnedUsage() const override;
  void EraseUnRefEntries() override;
-  void ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                              bool thread_safe) override;
+  void ApplyToSomeEntries(
+      const std::function<void(const Slice& key, void* value, size_t charge,
+                               DeleterFn deleter)>& callback,
+      uint32_t average_entries_per_lock, uint32_t* state) override;

 private:
  static const uint32_t kInCacheBit = 1;
@@ -404,22 +426,46 @@ size_t ClockCacheShard::GetPinnedUsage() const {
  return pinned_usage_.load(std::memory_order_relaxed);
 }

-void ClockCacheShard::ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                                             bool thread_safe) {
-  if (thread_safe) {
-    mutex_.Lock();
+void ClockCacheShard::ApplyToSomeEntries(
+    const std::function<void(const Slice& key, void* value, size_t charge,
+                             DeleterFn deleter)>& callback,
+    uint32_t average_entries_per_lock, uint32_t* state) {
+  assert(average_entries_per_lock > 0);
+  MutexLock lock(&mutex_);
+
+  // Figure out the range to iterate, update `state`
+  size_t list_size = list_.size();
+  size_t start_idx = *state;
+  size_t end_idx = start_idx + average_entries_per_lock;
+  if (start_idx > list_size) {
+    // Shouldn't reach here, but recoverable
+    assert(false);
+    // Mark finished with all
+    *state = UINT32_MAX;
+    return;
  }
-  for (auto& handle : list_) {
-    // Use relaxed semantics instead of acquire semantics since we are either
-    // holding mutex, or don't have thread safe requirement.
+  if (end_idx >= list_size || end_idx >= UINT32_MAX) {
+    // This also includes the hypothetical case of >4 billion
+    // cache handles.
+    end_idx = list_size;
+    // Mark finished with all
+    *state = UINT32_MAX;
+  } else {
+    *state = static_cast<uint32_t>(end_idx);
+  }
+
+  // Do the iteration
+  auto cur = list_.begin() + start_idx;
+  auto end = list_.begin() + end_idx;
+  for (; cur != end; ++cur) {
+    const CacheHandle& handle = *cur;
+    // Use relaxed semantics instead of acquire semantics since we are
+    // holding mutex
    uint32_t flags = handle.flags.load(std::memory_order_relaxed);
    if (InCache(flags)) {
-      callback(handle.value, handle.charge);
+      callback(handle.key, handle.value, handle.charge, handle.deleter);
    }
  }
-  if (thread_safe) {
-    mutex_.Unlock();
-  }
 }

 void ClockCacheShard::RecycleHandle(CacheHandle* handle,
@@ -428,10 +474,8 @@ void ClockCacheShard::RecycleHandle(CacheHandle* handle,
  assert(!InCache(handle->flags) && CountRefs(handle->flags) == 0);
  context->to_delete_key.push_back(handle->key.data());
  context->to_delete_value.emplace_back(*handle);
-  size_t total_charge = handle->CalcTotalCharge(metadata_charge_policy_);
-  handle->key.clear();
-  handle->value = nullptr;
-  handle->deleter = nullptr;
+  size_t total_charge = handle->GetTotalCharge();
+  // clearing `handle` fields would go here but not strictly required
  recycle_.push_back(handle);
  usage_.fetch_sub(total_charge, std::memory_order_relaxed);
 }
@@ -459,7 +503,7 @@ bool ClockCacheShard::Ref(Cache::Handle* h) {
                                            std::memory_order_relaxed)) {
      if (CountRefs(flags) == 0) {
        // No reference count before the operation.
-        size_t total_charge = handle->CalcTotalCharge(metadata_charge_policy_);
+        size_t total_charge = handle->GetTotalCharge();
        pinned_usage_.fetch_add(total_charge, std::memory_order_relaxed);
      }
      return true;
@@ -473,6 +517,11 @@ bool ClockCacheShard::Unref(CacheHandle* handle, bool set_usage,
  if (set_usage) {
    handle->flags.fetch_or(kUsageBit, std::memory_order_relaxed);
  }
+  // If the handle reaches state refs=0 and InCache=true after this
+  // atomic operation then we cannot access `handle` afterward, because
+  // it could be evicted before we access the `handle`.
+  size_t total_charge = handle->GetTotalCharge();
+
  // Use acquire-release semantics as previous operations on the cache entry
  // has to be order before reference count is decreased, and potential cleanup
  // of the entry has to be order after.
@@ -480,7 +529,6 @@ bool ClockCacheShard::Unref(CacheHandle* handle, bool set_usage,
  assert(CountRefs(flags) > 0);
  if (CountRefs(flags) == 1) {
    // this is the last reference.
-    size_t total_charge = handle->CalcTotalCharge(metadata_charge_policy_);
    pinned_usage_.fetch_sub(total_charge, std::memory_order_relaxed);
    // Cleanup if it is the last reference.
    if (!InCache(flags)) {
@@ -512,7 +560,7 @@ bool ClockCacheShard::TryEvict(CacheHandle* handle, CleanupContext* context) {
  if (handle->flags.compare_exchange_strong(flags, 0, std::memory_order_acquire,
                                            std::memory_order_relaxed)) {
    bool erased __attribute__((__unused__)) =
-        table_.erase(CacheKey(handle->key, handle->hash));
+        table_.erase(ClockCacheKey(handle->key, handle->hash));
    assert(erased);
    RecycleHandle(handle, context);
    return true;
@@ -567,8 +615,9 @@ CacheHandle* ClockCacheShard::Insert(
    void (*deleter)(const Slice& key, void* value), bool hold_reference,
    CleanupContext* context, bool* overwritten) {
  assert(overwritten != nullptr && *overwritten == false);
-  size_t total_charge =
-      CacheHandle::CalcTotalCharge(key, charge, metadata_charge_policy_);
+  uint32_t meta_charge =
+      CacheHandle::CalcMetadataCharge(key, metadata_charge_policy_);
+  size_t total_charge = charge + meta_charge;
  MutexLock l(&mutex_);
  bool success = EvictFromCache(total_charge, context);
  bool strict = strict_capacity_limit_.load(std::memory_order_relaxed);
@@ -594,17 +643,27 @@ CacheHandle* ClockCacheShard::Insert(
  handle->hash = hash;
  handle->value = value;
  handle->charge = charge;
+  handle->meta_charge = meta_charge;
  handle->deleter = deleter;
  uint32_t flags = hold_reference ? kInCacheBit + kOneRef : kInCacheBit;
+
+  // TODO investigate+fix suspected race condition:
+  // [thread 1] Lookup starts, up to Ref()
+  // [thread 2] Erase/evict the entry just looked up
+  // [thread 1] Ref() the handle, even though it's in the recycle bin
+  // [thread 2] Insert with recycling that handle
+  // Here we obliterate the other thread's Ref
+  // Possible fix: never blindly overwrite the flags, but only make
+  // relative updates (fetch_add, etc).
  handle->flags.store(flags, std::memory_order_relaxed);
  HashTable::accessor accessor;
-  if (table_.find(accessor, CacheKey(key, hash))) {
+  if (table_.find(accessor, ClockCacheKey(key, hash))) {
    *overwritten = true;
    CacheHandle* existing_handle = accessor->second;
    table_.erase(accessor);
    UnsetInCache(existing_handle, context);
  }
-  table_.insert(HashTable::value_type(CacheKey(key, hash), handle));
+  table_.insert(HashTable::value_type(ClockCacheKey(key, hash), handle));
  if (hold_reference) {
    pinned_usage_.fetch_add(total_charge, std::memory_order_relaxed);
  }
@@ -628,7 +687,7 @@ Status ClockCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
  Status s;
  if (out_handle != nullptr) {
    if (handle == nullptr) {
-      s = Status::Incomplete("Insert failed due to LRU cache being full.");
+      s = Status::Incomplete("Insert failed due to CLOCK cache being full.");
    } else {
      *out_handle = reinterpret_cast<Cache::Handle*>(handle);
    }
@@ -643,7 +702,7 @@ Status ClockCacheShard::Insert(const Slice& key, uint32_t hash, void* value,

 Cache::Handle* ClockCacheShard::Lookup(const Slice& key, uint32_t hash) {
  HashTable::const_accessor accessor;
-  if (!table_.find(accessor, CacheKey(key, hash))) {
+  if (!table_.find(accessor, ClockCacheKey(key, hash))) {
    return nullptr;
  }
  CacheHandle* handle = accessor->second;
@@ -666,11 +725,11 @@ Cache::Handle* ClockCacheShard::Lookup(const Slice& key, uint32_t hash) {
  return reinterpret_cast<Cache::Handle*>(handle);
 }

-bool ClockCacheShard::Release(Cache::Handle* h, bool force_erase) {
+bool ClockCacheShard::Release(Cache::Handle* h, bool erase_if_last_ref) {
  CleanupContext context;
  CacheHandle* handle = reinterpret_cast<CacheHandle*>(h);
  bool erased = Unref(handle, true, &context);
-  if (force_erase && !erased) {
+  if (erase_if_last_ref && !erased) {
    erased = EraseAndConfirm(handle->key, handle->hash, &context);
  }
  Cleanup(context);
@@ -688,7 +747,7 @@ bool ClockCacheShard::EraseAndConfirm(const Slice& key, uint32_t hash,
  MutexLock l(&mutex_);
  HashTable::accessor accessor;
  bool erased = false;
-  if (table_.find(accessor, CacheKey(key, hash))) {
+  if (table_.find(accessor, ClockCacheKey(key, hash))) {
    CacheHandle* handle = accessor->second;
    table_.erase(accessor);
    erased = UnsetInCache(handle, context);
@@ -726,11 +785,11 @@ class ClockCache final : public ShardedCache {

  const char* Name() const override { return "ClockCache"; }

-  CacheShard* GetShard(int shard) override {
+  CacheShard* GetShard(uint32_t shard) override {
    return reinterpret_cast<CacheShard*>(&shards_[shard]);
  }

-  const CacheShard* GetShard(int shard) const override {
+  const CacheShard* GetShard(uint32_t shard) const override {
    return reinterpret_cast<CacheShard*>(&shards_[shard]);
  }

@@ -746,7 +805,18 @@ class ClockCache final : public ShardedCache {
    return reinterpret_cast<const CacheHandle*>(handle)->hash;
  }

-  void DisownData() override { shards_ = nullptr; }
+  DeleterFn GetDeleter(Handle* handle) const override {
+    return reinterpret_cast<const CacheHandle*>(handle)->deleter;
+  }
+
+  void DisownData() override {
+    // Leak data only if that won't generate an ASAN/valgrind warning
+    if (!kMustFreeHeapAllocations) {
+      shards_ = nullptr;
+    }
+  }
+
+  void WaitAll(std::vector<Handle*>& /*handles*/) override {}

 private:
  ClockCacheShard* shards_;
@@ -10,24 +10,30 @@
 #include "cache/lru_cache.h"

 #include <cassert>
+#include <cstdint>
 #include <cstdio>
-#include <string>

+#include "monitoring/perf_context_imp.h"
+#include "monitoring/statistics.h"
+#include "port/lang.h"
 #include "util/mutexlock.h"

 namespace ROCKSDB_NAMESPACE {

-LRUHandleTable::LRUHandleTable() : list_(nullptr), length_(0), elems_(0) {
-  Resize();
-}
+LRUHandleTable::LRUHandleTable(int max_upper_hash_bits)
+    : length_bits_(/* historical starting size*/ 4),
+      list_(new LRUHandle* [size_t{1} << length_bits_] {}),
+      elems_(0),
+      max_length_bits_(max_upper_hash_bits) {}

 LRUHandleTable::~LRUHandleTable() {
-  ApplyToAllCacheEntries([](LRUHandle* h) {
-    if (!h->HasRefs()) {
-      h->Free();
-    }
-  });
-  delete[] list_;
+  ApplyToEntriesRange(
+      [](LRUHandle* h) {
+        if (!h->HasRefs()) {
+          h->Free();
+        }
+      },
+      0, uint32_t{1} << length_bits_);
 }

 LRUHandle* LRUHandleTable::Lookup(const Slice& key, uint32_t hash) {
@@ -41,7 +47,7 @@ LRUHandle* LRUHandleTable::Insert(LRUHandle* h) {
  *ptr = h;
  if (old == nullptr) {
    ++elems_;
-    if (elems_ > length_) {
+    if ((elems_ >> length_bits_) > 0) {  // elems_ >= length
      // Since each cache entry is fairly large, we aim for a small
      // average linked list length (<= 1).
      Resize();
@@ -61,7 +67,7 @@ LRUHandle* LRUHandleTable::Remove(const Slice& key, uint32_t hash) {
 }

 LRUHandle** LRUHandleTable::FindPointer(const Slice& key, uint32_t hash) {
-  LRUHandle** ptr = &list_[hash & (length_ - 1)];
+  LRUHandle** ptr = &list_[hash >> (32 - length_bits_)];
  while (*ptr != nullptr && ((*ptr)->hash != hash || key != (*ptr)->key())) {
    ptr = &(*ptr)->next_hash;
  }
@@ -69,19 +75,28 @@ LRUHandle** LRUHandleTable::FindPointer(const Slice& key, uint32_t hash) {
 }

 void LRUHandleTable::Resize() {
-  uint32_t new_length = 16;
-  while (new_length < elems_ * 1.5) {
-    new_length *= 2;
+  if (length_bits_ >= max_length_bits_) {
+    // Due to reaching limit of hash information, if we made the table bigger,
+    // we would allocate more addresses but only the same number would be used.
+    return;
  }
-  LRUHandle** new_list = new LRUHandle*[new_length];
-  memset(new_list, 0, sizeof(new_list[0]) * new_length);
+  if (length_bits_ >= 31) {
+    // Avoid undefined behavior shifting uint32_t by 32.
+    return;
+  }
+
+  uint32_t old_length = uint32_t{1} << length_bits_;
+  int new_length_bits = length_bits_ + 1;
+  std::unique_ptr<LRUHandle* []> new_list {
+    new LRUHandle* [size_t{1} << new_length_bits] {}
+  };
  uint32_t count = 0;
-  for (uint32_t i = 0; i < length_; i++) {
+  for (uint32_t i = 0; i < old_length; i++) {
    LRUHandle* h = list_[i];
    while (h != nullptr) {
      LRUHandle* next = h->next_hash;
      uint32_t hash = h->hash;
-      LRUHandle** ptr = &new_list[hash & (new_length - 1)];
+      LRUHandle** ptr = &new_list[hash >> (32 - new_length_bits)];
      h->next_hash = *ptr;
      *ptr = h;
      h = next;
@@ -89,25 +104,27 @@ void LRUHandleTable::Resize() {
    }
  }
  assert(elems_ == count);
-  delete[] list_;
-  list_ = new_list;
-  length_ = new_length;
+  list_ = std::move(new_list);
+  length_bits_ = new_length_bits;
 }

-LRUCacheShard::LRUCacheShard(size_t capacity, bool strict_capacity_limit,
-                             double high_pri_pool_ratio,
-                             bool use_adaptive_mutex,
-                             CacheMetadataChargePolicy metadata_charge_policy)
+LRUCacheShard::LRUCacheShard(
+    size_t capacity, bool strict_capacity_limit, double high_pri_pool_ratio,
+    bool use_adaptive_mutex, CacheMetadataChargePolicy metadata_charge_policy,
+    int max_upper_hash_bits,
+    const std::shared_ptr<SecondaryCache>& secondary_cache)
    : capacity_(0),
      high_pri_pool_usage_(0),
      strict_capacity_limit_(strict_capacity_limit),
      high_pri_pool_ratio_(high_pri_pool_ratio),
      high_pri_pool_capacity_(0),
+      table_(max_upper_hash_bits),
      usage_(0),
      lru_usage_(0),
-      mutex_(use_adaptive_mutex) {
+      mutex_(use_adaptive_mutex),
+      secondary_cache_(secondary_cache) {
  set_metadata_charge_policy(metadata_charge_policy);
-  // Make empty circular linked list
+  // Make empty circular linked list.
  lru_.next = &lru_;
  lru_.prev = &lru_;
  lru_low_pri_ = &lru_;
@@ -120,7 +137,7 @@ void LRUCacheShard::EraseUnRefEntries() {
    MutexLock l(&mutex_);
    while (lru_.next != &lru_) {
      LRUHandle* old = lru_.next;
-      // LRU list contains only elements which can be evicted
+      // LRU list contains only elements which can be evicted.
      assert(old->InCache() && !old->HasRefs());
      LRU_Remove(old);
      table_.Remove(old->key(), old->hash);
@@ -137,19 +154,40 @@ void LRUCacheShard::EraseUnRefEntries() {
  }
 }

-void LRUCacheShard::ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                                           bool thread_safe) {
-  const auto applyCallback = [&]() {
-    table_.ApplyToAllCacheEntries(
-        [callback](LRUHandle* h) { callback(h->value, h->charge); });
-  };
+void LRUCacheShard::ApplyToSomeEntries(
+    const std::function<void(const Slice& key, void* value, size_t charge,
+                             DeleterFn deleter)>& callback,
+    uint32_t average_entries_per_lock, uint32_t* state) {
+  // The state is essentially going to be the starting hash, which works
+  // nicely even if we resize between calls because we use upper-most
+  // hash bits for table indexes.
+  MutexLock l(&mutex_);
+  uint32_t length_bits = table_.GetLengthBits();
+  uint32_t length = uint32_t{1} << length_bits;

-  if (thread_safe) {
-    MutexLock l(&mutex_);
-    applyCallback();
+  assert(average_entries_per_lock > 0);
+  // Assuming we are called with same average_entries_per_lock repeatedly,
+  // this simplifies some logic (index_end will not overflow).
+  assert(average_entries_per_lock < length || *state == 0);
+
+  uint32_t index_begin = *state >> (32 - length_bits);
+  uint32_t index_end = index_begin + average_entries_per_lock;
+  if (index_end >= length) {
+    // Going to end
+    index_end = length;
+    *state = UINT32_MAX;
  } else {
-    applyCallback();
+    *state = index_end << (32 - length_bits);
  }
+
+  table_.ApplyToEntriesRange(
+      [callback](LRUHandle* h) {
+        DeleterFn deleter = h->IsSecondaryCacheCompatible()
+                                ? h->info_.helper->del_cb
+                                : h->info_.deleter;
+        callback(h->key(), h->value, h->charge, deleter);
+      },
+      index_begin, index_end);
 }

 void LRUCacheShard::TEST_GetLRUList(LRUHandle** lru, LRUHandle** lru_low_pri) {
@@ -235,7 +273,7 @@ void LRUCacheShard::EvictFromLRU(size_t charge,
                                 autovector<LRUHandle*>* deleted) {
  while ((usage_ + charge) > capacity_ && lru_.next != &lru_) {
    LRUHandle* old = lru_.next;
-    // LRU list contains only elements which can be evicted
+    // LRU list contains only elements which can be evicted.
    assert(old->InCache() && !old->HasRefs());
    LRU_Remove(old);
    table_.Remove(old->key(), old->hash);
@@ -256,8 +294,14 @@ void LRUCacheShard::SetCapacity(size_t capacity) {
    EvictFromLRU(0, &last_reference_list);
  }

-  // Free the entries outside of mutex for performance reasons
+  // Try to insert the evicted entries into tiered cache.
+  // Free the entries outside of mutex for performance reasons.
  for (auto entry : last_reference_list) {
+    if (secondary_cache_ && entry->IsSecondaryCacheCompatible() &&
+        !entry->IsPromoted()) {
+      secondary_cache_->Insert(entry->key(), entry->value, entry->info_.helper)
+          .PermitUncheckedError();
+    }
    entry->Free();
  }
 }
@@ -267,116 +311,31 @@ void LRUCacheShard::SetStrictCapacityLimit(bool strict_capacity_limit) {
  strict_capacity_limit_ = strict_capacity_limit;
 }

-Cache::Handle* LRUCacheShard::Lookup(const Slice& key, uint32_t hash) {
-  MutexLock l(&mutex_);
-  LRUHandle* e = table_.Lookup(key, hash);
-  if (e != nullptr) {
-    assert(e->InCache());
-    if (!e->HasRefs()) {
-      // The entry is in LRU since it's in hash and has no external references
-      LRU_Remove(e);
-    }
-    e->Ref();
-    e->SetHit();
-  }
-  return reinterpret_cast<Cache::Handle*>(e);
-}
-
-bool LRUCacheShard::Ref(Cache::Handle* h) {
-  LRUHandle* e = reinterpret_cast<LRUHandle*>(h);
-  MutexLock l(&mutex_);
-  // To create another reference - entry must be already externally referenced
-  assert(e->HasRefs());
-  e->Ref();
-  return true;
-}
-
-void LRUCacheShard::SetHighPriorityPoolRatio(double high_pri_pool_ratio) {
-  MutexLock l(&mutex_);
-  high_pri_pool_ratio_ = high_pri_pool_ratio;
-  high_pri_pool_capacity_ = capacity_ * high_pri_pool_ratio_;
-  MaintainPoolSize();
-}
-
-bool LRUCacheShard::Release(Cache::Handle* handle, bool force_erase) {
-  if (handle == nullptr) {
-    return false;
-  }
-  LRUHandle* e = reinterpret_cast<LRUHandle*>(handle);
-  bool last_reference = false;
-  {
-    MutexLock l(&mutex_);
-    last_reference = e->Unref();
-    if (last_reference && e->InCache()) {
-      // The item is still in cache, and nobody else holds a reference to it
-      if (usage_ > capacity_ || force_erase) {
-        // The LRU list must be empty since the cache is full
-        assert(lru_.next == &lru_ || force_erase);
-        // Take this opportunity and remove the item
-        table_.Remove(e->key(), e->hash);
-        e->SetInCache(false);
-      } else {
-        // Put the item back on the LRU list, and don't free it
-        LRU_Insert(e);
-        last_reference = false;
-      }
-    }
-    if (last_reference) {
-      size_t total_charge = e->CalcTotalCharge(metadata_charge_policy_);
-      assert(usage_ >= total_charge);
-      usage_ -= total_charge;
-    }
-  }
-
-  // Free the entry here outside of mutex for performance reasons
-  if (last_reference) {
-    e->Free();
-  }
-  return last_reference;
-}
-
-Status LRUCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
-                             size_t charge,
-                             void (*deleter)(const Slice& key, void* value),
-                             Cache::Handle** handle, Cache::Priority priority) {
-  // Allocate the memory here outside of the mutex
-  // If the cache is full, we'll have to release it
-  // It shouldn't happen very often though.
-  LRUHandle* e = reinterpret_cast<LRUHandle*>(
-      new char[sizeof(LRUHandle) - 1 + key.size()]);
+Status LRUCacheShard::InsertItem(LRUHandle* e, Cache::Handle** handle,
+                                 bool free_handle_on_fail) {
  Status s = Status::OK();
  autovector<LRUHandle*> last_reference_list;
-
-  e->value = value;
-  e->deleter = deleter;
-  e->charge = charge;
-  e->key_length = key.size();
-  e->flags = 0;
-  e->hash = hash;
-  e->refs = 0;
-  e->next = e->prev = nullptr;
-  e->SetInCache(true);
-  e->SetPriority(priority);
-  memcpy(e->key_data, key.data(), key.size());
  size_t total_charge = e->CalcTotalCharge(metadata_charge_policy_);

  {
    MutexLock l(&mutex_);

    // Free the space following strict LRU policy until enough space
-    // is freed or the lru list is empty
+    // is freed or the lru list is empty.
    EvictFromLRU(total_charge, &last_reference_list);

    if ((usage_ + total_charge) > capacity_ &&
        (strict_capacity_limit_ || handle == nullptr)) {
+      e->SetInCache(false);
      if (handle == nullptr) {
        // Don't insert the entry but still return ok, as if the entry inserted
        // into cache and get evicted immediately.
-        e->SetInCache(false);
        last_reference_list.push_back(e);
      } else {
-        delete[] reinterpret_cast<char*>(e);
-        *handle = nullptr;
+        if (free_handle_on_fail) {
+          delete[] reinterpret_cast<char*>(e);
+          *handle = nullptr;
+        }
        s = Status::Incomplete("Insert failed due to LRU cache being full.");
      }
    } else {
@@ -389,7 +348,7 @@ Status LRUCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
        assert(old->InCache());
        old->SetInCache(false);
        if (!old->HasRefs()) {
-          // old is on LRU because it's in cache and its reference count is 0
+          // old is on LRU because it's in cache and its reference count is 0.
          LRU_Remove(old);
          size_t old_total_charge =
              old->CalcTotalCharge(metadata_charge_policy_);
@@ -401,20 +360,228 @@ Status LRUCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
      if (handle == nullptr) {
        LRU_Insert(e);
      } else {
-        e->Ref();
+        // If caller already holds a ref, no need to take one here.
+        if (!e->HasRefs()) {
+          e->Ref();
+        }
        *handle = reinterpret_cast<Cache::Handle*>(e);
      }
    }
  }

-  // Free the entries here outside of mutex for performance reasons
+  // Try to insert the evicted entries into the secondary cache.
+  // Free the entries here outside of mutex for performance reasons.
  for (auto entry : last_reference_list) {
+    if (secondary_cache_ && entry->IsSecondaryCacheCompatible() &&
+        !entry->IsPromoted()) {
+      secondary_cache_->Insert(entry->key(), entry->value, entry->info_.helper)
+          .PermitUncheckedError();
+    }
    entry->Free();
  }

  return s;
 }

+void LRUCacheShard::Promote(LRUHandle* e) {
+  SecondaryCacheResultHandle* secondary_handle = e->sec_handle;
+
+  assert(secondary_handle->IsReady());
+  e->SetIncomplete(false);
+  e->SetInCache(true);
+  e->SetPromoted(true);
+  e->value = secondary_handle->Value();
+  e->charge = secondary_handle->Size();
+  delete secondary_handle;
+
+  // This call could fail if the cache is over capacity and
+  // strict_capacity_limit_ is true. In such a case, we don't want
+  // InsertItem() to free the handle, since the item is already in memory
+  // and the caller will most likely just read from disk if we erase it here.
+  if (e->value) {
+    Cache::Handle* handle = reinterpret_cast<Cache::Handle*>(e);
+    Status s = InsertItem(e, &handle, /*free_handle_on_fail=*/false);
+    if (!s.ok()) {
+      // Item is in memory, but not accounted against the cache capacity.
+      // When the handle is released, the item should get deleted.
+      assert(!e->InCache());
+    }
+  } else {
+    // Since the secondary cache lookup failed, mark the item as not in cache
+    // Don't charge the cache as its only metadata that'll shortly be released
+    MutexLock l(&mutex_);
+    e->charge = 0;
+    e->SetInCache(false);
+  }
+}
+
+Cache::Handle* LRUCacheShard::Lookup(
+    const Slice& key, uint32_t hash,
+    const ShardedCache::CacheItemHelper* helper,
+    const ShardedCache::CreateCallback& create_cb, Cache::Priority priority,
+    bool wait, Statistics* stats) {
+  LRUHandle* e = nullptr;
+  {
+    MutexLock l(&mutex_);
+    e = table_.Lookup(key, hash);
+    if (e != nullptr) {
+      assert(e->InCache());
+      if (!e->HasRefs()) {
+        // The entry is in LRU since it's in hash and has no external references
+        LRU_Remove(e);
+      }
+      e->Ref();
+      e->SetHit();
+    }
+  }
+
+  // If handle table lookup failed, then allocate a handle outside the
+  // mutex if we're going to lookup in the secondary cache.
+  // Only support synchronous for now.
+  // TODO: Support asynchronous lookup in secondary cache
+  if (!e && secondary_cache_ && helper && helper->saveto_cb) {
+    // For objects from the secondary cache, we expect the caller to provide
+    // a way to create/delete the primary cache object. The only case where
+    // a deleter would not be required is for dummy entries inserted for
+    // accounting purposes, which we won't demote to the secondary cache
+    // anyway.
+    assert(create_cb && helper->del_cb);
+    std::unique_ptr<SecondaryCacheResultHandle> secondary_handle =
+        secondary_cache_->Lookup(key, create_cb, wait);
+    if (secondary_handle != nullptr) {
+      e = reinterpret_cast<LRUHandle*>(
+          new char[sizeof(LRUHandle) - 1 + key.size()]);
+
+      e->flags = 0;
+      e->SetSecondaryCacheCompatible(true);
+      e->info_.helper = helper;
+      e->key_length = key.size();
+      e->hash = hash;
+      e->refs = 0;
+      e->next = e->prev = nullptr;
+      e->SetPriority(priority);
+      memcpy(e->key_data, key.data(), key.size());
+      e->value = nullptr;
+      e->sec_handle = secondary_handle.release();
+      e->Ref();
+
+      if (wait) {
+        Promote(e);
+        if (!e->value) {
+          // The secondary cache returned a handle, but the lookup failed.
+          e->Unref();
+          e->Free();
+          e = nullptr;
+        } else {
+          PERF_COUNTER_ADD(secondary_cache_hit_count, 1);
+          RecordTick(stats, SECONDARY_CACHE_HITS);
+        }
+      } else {
+        // If wait is false, we always return a handle and let the caller
+        // release the handle after checking for success or failure.
+        e->SetIncomplete(true);
+        // This may be slightly inaccurate, if the lookup eventually fails.
+        // But the probability is very low.
+        PERF_COUNTER_ADD(secondary_cache_hit_count, 1);
+        RecordTick(stats, SECONDARY_CACHE_HITS);
+      }
+    }
+  }
+  return reinterpret_cast<Cache::Handle*>(e);
+}
+
+bool LRUCacheShard::Ref(Cache::Handle* h) {
+  LRUHandle* e = reinterpret_cast<LRUHandle*>(h);
+  MutexLock l(&mutex_);
+  // To create another reference - entry must be already externally referenced.
+  assert(e->HasRefs());
+  e->Ref();
+  return true;
+}
+
+void LRUCacheShard::SetHighPriorityPoolRatio(double high_pri_pool_ratio) {
+  MutexLock l(&mutex_);
+  high_pri_pool_ratio_ = high_pri_pool_ratio;
+  high_pri_pool_capacity_ = capacity_ * high_pri_pool_ratio_;
+  MaintainPoolSize();
+}
+
+bool LRUCacheShard::Release(Cache::Handle* handle, bool erase_if_last_ref) {
+  if (handle == nullptr) {
+    return false;
+  }
+  LRUHandle* e = reinterpret_cast<LRUHandle*>(handle);
+  bool last_reference = false;
+  {
+    MutexLock l(&mutex_);
+    last_reference = e->Unref();
+    if (last_reference && e->InCache()) {
+      // The item is still in cache, and nobody else holds a reference to it.
+      if (usage_ > capacity_ || erase_if_last_ref) {
+        // The LRU list must be empty since the cache is full.
+        assert(lru_.next == &lru_ || erase_if_last_ref);
+        // Take this opportunity and remove the item.
+        table_.Remove(e->key(), e->hash);
+        e->SetInCache(false);
+      } else {
+        // Put the item back on the LRU list, and don't free it.
+        LRU_Insert(e);
+        last_reference = false;
+      }
+    }
+    // If it was the last reference, and the entry is either not secondary
+    // cache compatible (i.e a dummy entry for accounting), or is secondary
+    // cache compatible and has a non-null value, then decrement the cache
+    // usage. If value is null in the latter case, taht means the lookup
+    // failed and we didn't charge the cache.
+    if (last_reference && (!e->IsSecondaryCacheCompatible() || e->value)) {
+      size_t total_charge = e->CalcTotalCharge(metadata_charge_policy_);
+      assert(usage_ >= total_charge);
+      usage_ -= total_charge;
+    }
+  }
+
+  // Free the entry here outside of mutex for performance reasons.
+  if (last_reference) {
+    e->Free();
+  }
+  return last_reference;
+}
+
+Status LRUCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
+                             size_t charge,
+                             void (*deleter)(const Slice& key, void* value),
+                             const Cache::CacheItemHelper* helper,
+                             Cache::Handle** handle, Cache::Priority priority) {
+  // Allocate the memory here outside of the mutex.
+  // If the cache is full, we'll have to release it.
+  // It shouldn't happen very often though.
+  LRUHandle* e = reinterpret_cast<LRUHandle*>(
+      new char[sizeof(LRUHandle) - 1 + key.size()]);
+
+  e->value = value;
+  e->flags = 0;
+  if (helper) {
+    e->SetSecondaryCacheCompatible(true);
+    e->info_.helper = helper;
+  } else {
+#ifdef __SANITIZE_THREAD__
+    e->is_secondary_cache_compatible_for_tsan = false;
+#endif  // __SANITIZE_THREAD__
+    e->info_.deleter = deleter;
+  }
+  e->charge = charge;
+  e->key_length = key.size();
+  e->hash = hash;
+  e->refs = 0;
+  e->next = e->prev = nullptr;
+  e->SetInCache(true);
+  e->SetPriority(priority);
+  memcpy(e->key_data, key.data(), key.size());
+
+  return InsertItem(e, handle, /* free_handle_on_fail */ true);
+}
+
 void LRUCacheShard::Erase(const Slice& key, uint32_t hash) {
  LRUHandle* e;
  bool last_reference = false;
@@ -435,13 +602,25 @@ void LRUCacheShard::Erase(const Slice& key, uint32_t hash) {
    }
  }

-  // Free the entry here outside of mutex for performance reasons
-  // last_reference will only be true if e != nullptr
+  // Free the entry here outside of mutex for performance reasons.
+  // last_reference will only be true if e != nullptr.
  if (last_reference) {
    e->Free();
  }
 }

+bool LRUCacheShard::IsReady(Cache::Handle* handle) {
+  LRUHandle* e = reinterpret_cast<LRUHandle*>(handle);
+  MutexLock l(&mutex_);
+  bool ready = true;
+  if (e->IsPending()) {
+    assert(secondary_cache_);
+    assert(e->sec_handle);
+    ready = e->sec_handle->IsReady();
+  }
+  return ready;
+}
+
 size_t LRUCacheShard::GetUsage() const {
  MutexLock l(&mutex_);
  return usage_;
@@ -468,7 +647,8 @@ LRUCache::LRUCache(size_t capacity, int num_shard_bits,
                   bool strict_capacity_limit, double high_pri_pool_ratio,
                   std::shared_ptr<MemoryAllocator> allocator,
                   bool use_adaptive_mutex,
-                   CacheMetadataChargePolicy metadata_charge_policy)
+                   CacheMetadataChargePolicy metadata_charge_policy,
+                   const std::shared_ptr<SecondaryCache>& secondary_cache)
    : ShardedCache(capacity, num_shard_bits, strict_capacity_limit,
                   std::move(allocator)) {
  num_shards_ = 1 << num_shard_bits;
@@ -476,10 +656,12 @@ LRUCache::LRUCache(size_t capacity, int num_shard_bits,
      port::cacheline_aligned_alloc(sizeof(LRUCacheShard) * num_shards_));
  size_t per_shard = (capacity + (num_shards_ - 1)) / num_shards_;
  for (int i = 0; i < num_shards_; i++) {
-    new (&shards_[i])
-        LRUCacheShard(per_shard, strict_capacity_limit, high_pri_pool_ratio,
-                      use_adaptive_mutex, metadata_charge_policy);
+    new (&shards_[i]) LRUCacheShard(
+        per_shard, strict_capacity_limit, high_pri_pool_ratio,
+        use_adaptive_mutex, metadata_charge_policy,
+        /* max_upper_hash_bits */ 32 - num_shard_bits, secondary_cache);
  }
+  secondary_cache_ = secondary_cache;
 }

 LRUCache::~LRUCache() {
@@ -492,11 +674,11 @@ LRUCache::~LRUCache() {
  }
 }

-CacheShard* LRUCache::GetShard(int shard) {
+CacheShard* LRUCache::GetShard(uint32_t shard) {
  return reinterpret_cast<CacheShard*>(&shards_[shard]);
 }

-const CacheShard* LRUCache::GetShard(int shard) const {
+const CacheShard* LRUCache::GetShard(uint32_t shard) const {
  return reinterpret_cast<CacheShard*>(&shards_[shard]);
 }

@@ -508,23 +690,25 @@ size_t LRUCache::GetCharge(Handle* handle) const {
  return reinterpret_cast<const LRUHandle*>(handle)->charge;
 }

+Cache::DeleterFn LRUCache::GetDeleter(Handle* handle) const {
+  auto h = reinterpret_cast<const LRUHandle*>(handle);
+  if (h->IsSecondaryCacheCompatible()) {
+    return h->info_.helper->del_cb;
+  } else {
+    return h->info_.deleter;
+  }
+}
+
 uint32_t LRUCache::GetHash(Handle* handle) const {
  return reinterpret_cast<const LRUHandle*>(handle)->hash;
 }

 void LRUCache::DisownData() {
-// Do not drop data if compile with ASAN to suppress leak warning.
-#if defined(__clang__)
-#if !defined(__has_feature) || !__has_feature(address_sanitizer)
-  shards_ = nullptr;
-  num_shards_ = 0;
-#endif
-#else  // __clang__
-#ifndef __SANITIZE_ADDRESS__
-  shards_ = nullptr;
-  num_shards_ = 0;
-#endif  // !__SANITIZE_ADDRESS__
-#endif  // __clang__
+  // Leak data only if that won't generate an ASAN/valgrind warning.
+  if (!kMustFreeHeapAllocations) {
+    shards_ = nullptr;
+    num_shards_ = 0;
+  }
 }

 size_t LRUCache::TEST_GetLRUSize() {
@@ -543,24 +727,47 @@ double LRUCache::GetHighPriPoolRatio() {
  return result;
 }

-std::shared_ptr<Cache> NewLRUCache(const LRUCacheOptions& cache_opts) {
-  return NewLRUCache(cache_opts.capacity, cache_opts.num_shard_bits,
-                     cache_opts.strict_capacity_limit,
-                     cache_opts.high_pri_pool_ratio,
-                     cache_opts.memory_allocator, cache_opts.use_adaptive_mutex,
-                     cache_opts.metadata_charge_policy);
+void LRUCache::WaitAll(std::vector<Handle*>& handles) {
+  if (secondary_cache_) {
+    std::vector<SecondaryCacheResultHandle*> sec_handles;
+    sec_handles.reserve(handles.size());
+    for (Handle* handle : handles) {
+      if (!handle) {
+        continue;
+      }
+      LRUHandle* lru_handle = reinterpret_cast<LRUHandle*>(handle);
+      if (!lru_handle->IsPending()) {
+        continue;
+      }
+      sec_handles.emplace_back(lru_handle->sec_handle);
+    }
+    secondary_cache_->WaitAll(sec_handles);
+    for (Handle* handle : handles) {
+      if (!handle) {
+        continue;
+      }
+      LRUHandle* lru_handle = reinterpret_cast<LRUHandle*>(handle);
+      if (!lru_handle->IsPending()) {
+        continue;
+      }
+      uint32_t hash = GetHash(handle);
+      LRUCacheShard* shard = static_cast<LRUCacheShard*>(GetShard(Shard(hash)));
+      shard->Promote(lru_handle);
+    }
+  }
 }

 std::shared_ptr<Cache> NewLRUCache(
    size_t capacity, int num_shard_bits, bool strict_capacity_limit,
    double high_pri_pool_ratio,
    std::shared_ptr<MemoryAllocator> memory_allocator, bool use_adaptive_mutex,
-    CacheMetadataChargePolicy metadata_charge_policy) {
+    CacheMetadataChargePolicy metadata_charge_policy,
+    const std::shared_ptr<SecondaryCache>& secondary_cache) {
  if (num_shard_bits >= 20) {
-    return nullptr;  // the cache cannot be sharded into too many fine pieces
+    return nullptr;  // The cache cannot be sharded into too many fine pieces.
  }
  if (high_pri_pool_ratio < 0.0 || high_pri_pool_ratio > 1.0) {
-    // invalid high_pri_pool_ratio
+    // Invalid high_pri_pool_ratio
    return nullptr;
  }
  if (num_shard_bits < 0) {
@@ -568,7 +775,25 @@ std::shared_ptr<Cache> NewLRUCache(
  }
  return std::make_shared<LRUCache>(
      capacity, num_shard_bits, strict_capacity_limit, high_pri_pool_ratio,
-      std::move(memory_allocator), use_adaptive_mutex, metadata_charge_policy);
+      std::move(memory_allocator), use_adaptive_mutex, metadata_charge_policy,
+      secondary_cache);
 }

+std::shared_ptr<Cache> NewLRUCache(const LRUCacheOptions& cache_opts) {
+  return NewLRUCache(
+      cache_opts.capacity, cache_opts.num_shard_bits,
+      cache_opts.strict_capacity_limit, cache_opts.high_pri_pool_ratio,
+      cache_opts.memory_allocator, cache_opts.use_adaptive_mutex,
+      cache_opts.metadata_charge_policy, cache_opts.secondary_cache);
+}
+
+std::shared_ptr<Cache> NewLRUCache(
+    size_t capacity, int num_shard_bits, bool strict_capacity_limit,
+    double high_pri_pool_ratio,
+    std::shared_ptr<MemoryAllocator> memory_allocator, bool use_adaptive_mutex,
+    CacheMetadataChargePolicy metadata_charge_policy) {
+  return NewLRUCache(capacity, num_shard_bits, strict_capacity_limit,
+                     high_pri_pool_ratio, memory_allocator, use_adaptive_mutex,
+                     metadata_charge_policy, nullptr);
+}
 }  // namespace ROCKSDB_NAMESPACE
@@ -1,4 +1,4 @@
-//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
@@ -8,12 +8,14 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 #pragma once

+#include <memory>
 #include <string>

 #include "cache/sharded_cache.h"
-
+#include "port/lang.h"
 #include "port/malloc.h"
 #include "port/port.h"
+#include "rocksdb/secondary_cache.h"
 #include "util/autovector.h"

 namespace ROCKSDB_NAMESPACE {
@@ -49,8 +51,18 @@ namespace ROCKSDB_NAMESPACE {

 struct LRUHandle {
  void* value;
-  void (*deleter)(const Slice&, void* value);
-  LRUHandle* next_hash;
+  union Info {
+    Info() {}
+    ~Info() {}
+    Cache::DeleterFn deleter;
+    const ShardedCache::CacheItemHelper* helper;
+  } info_;
+  // An entry is not added to the LRUHandleTable until the secondary cache
+  // lookup is complete, so its safe to have this union.
+  union {
+    LRUHandle* next_hash;
+    SecondaryCacheResultHandle* sec_handle;
+  };
  LRUHandle* next;
  LRUHandle* prev;
  size_t charge;  // TODO(opt): Only allow uint32_t?
@@ -69,10 +81,24 @@ struct LRUHandle {
    IN_HIGH_PRI_POOL = (1 << 2),
    // Whether this entry has had any lookups (hits).
    HAS_HIT = (1 << 3),
+    // Can this be inserted into the secondary cache.
+    IS_SECONDARY_CACHE_COMPATIBLE = (1 << 4),
+    // Is the handle still being read from a lower tier.
+    IS_PENDING = (1 << 5),
+    // Has the item been promoted from a lower tier.
+    IS_PROMOTED = (1 << 6),
  };

  uint8_t flags;

+#ifdef __SANITIZE_THREAD__
+  // TSAN can report a false data race on flags, where one thread is writing
+  // to one of the mutable bits and another thread is reading this immutable
+  // bit. So precisely suppress that TSAN warning, we separate out this bit
+  // during TSAN runs.
+  bool is_secondary_cache_compatible_for_tsan;
+#endif  // __SANITIZE_THREAD__
+
  // Beginning of the key (MUST BE THE LAST FIELD IN THIS STRUCT!)
  char key_data[1];

@@ -95,6 +121,15 @@ struct LRUHandle {
  bool IsHighPri() const { return flags & IS_HIGH_PRI; }
  bool InHighPriPool() const { return flags & IN_HIGH_PRI_POOL; }
  bool HasHit() const { return flags & HAS_HIT; }
+  bool IsSecondaryCacheCompatible() const {
+#ifdef __SANITIZE_THREAD__
+    return is_secondary_cache_compatible_for_tsan;
+#else
+    return flags & IS_SECONDARY_CACHE_COMPATIBLE;
+#endif  // __SANITIZE_THREAD__
+  }
+  bool IsPending() const { return flags & IS_PENDING; }
+  bool IsPromoted() const { return flags & IS_PROMOTED; }

  void SetInCache(bool in_cache) {
    if (in_cache) {
@@ -122,15 +157,58 @@ struct LRUHandle {

  void SetHit() { flags |= HAS_HIT; }

+  void SetSecondaryCacheCompatible(bool compat) {
+    if (compat) {
+      flags |= IS_SECONDARY_CACHE_COMPATIBLE;
+    } else {
+      flags &= ~IS_SECONDARY_CACHE_COMPATIBLE;
+    }
+#ifdef __SANITIZE_THREAD__
+    is_secondary_cache_compatible_for_tsan = compat;
+#endif  // __SANITIZE_THREAD__
+  }
+
+  void SetIncomplete(bool incomp) {
+    if (incomp) {
+      flags |= IS_PENDING;
+    } else {
+      flags &= ~IS_PENDING;
+    }
+  }
+
+  void SetPromoted(bool promoted) {
+    if (promoted) {
+      flags |= IS_PROMOTED;
+    } else {
+      flags &= ~IS_PROMOTED;
+    }
+  }
+
  void Free() {
    assert(refs == 0);
-    if (deleter) {
-      (*deleter)(key(), value);
+#ifdef __SANITIZE_THREAD__
+    // Here we can safely assert they are the same without a data race reported
+    assert(((flags & IS_SECONDARY_CACHE_COMPATIBLE) != 0) ==
+           is_secondary_cache_compatible_for_tsan);
+#endif  // __SANITIZE_THREAD__
+    if (!IsSecondaryCacheCompatible() && info_.deleter) {
+      (*info_.deleter)(key(), value);
+    } else if (IsSecondaryCacheCompatible()) {
+      if (IsPending()) {
+        assert(sec_handle != nullptr);
+        SecondaryCacheResultHandle* tmp_sec_handle = sec_handle;
+        tmp_sec_handle->Wait();
+        value = tmp_sec_handle->Value();
+        delete tmp_sec_handle;
+      }
+      if (value) {
+        (*info_.helper->del_cb)(key(), value);
+      }
    }
    delete[] reinterpret_cast<char*>(this);
  }

-  // Calculate the memory usage by metadata
+  // Calculate the memory usage by metadata.
  inline size_t CalcTotalCharge(
      CacheMetadataChargePolicy metadata_charge_policy) {
    size_t meta_charge = 0;
@@ -138,7 +216,7 @@ struct LRUHandle {
 #ifdef ROCKSDB_MALLOC_USABLE_SIZE
      meta_charge += malloc_usable_size(static_cast<void*>(this));
 #else
-      // This is the size that is used when a new handle is created
+      // This is the size that is used when a new handle is created.
      meta_charge += sizeof(LRUHandle) - 1 + key_length;
 #endif
    }
@@ -153,7 +231,10 @@ struct LRUHandle {
 // 4.4.3's builtin hashtable.
 class LRUHandleTable {
 public:
-  LRUHandleTable();
+  // If the table uses more hash bits than `max_upper_hash_bits`,
+  // it will eat into the bits used for sharding, which are constant
+  // for a given LRUHandleTable.
+  explicit LRUHandleTable(int max_upper_hash_bits);
  ~LRUHandleTable();

  LRUHandle* Lookup(const Slice& key, uint32_t hash);
@@ -161,8 +242,8 @@ class LRUHandleTable {
  LRUHandle* Remove(const Slice& key, uint32_t hash);

  template <typename T>
-  void ApplyToAllCacheEntries(T func) {
-    for (uint32_t i = 0; i < length_; i++) {
+  void ApplyToEntriesRange(T func, uint32_t index_begin, uint32_t index_end) {
+    for (uint32_t i = index_begin; i < index_end; i++) {
      LRUHandle* h = list_[i];
      while (h != nullptr) {
        auto n = h->next_hash;
@@ -173,6 +254,8 @@ class LRUHandleTable {
    }
  }

+  int GetLengthBits() const { return length_bits_; }
+
 private:
  // Return a pointer to slot that points to a cache entry that
  // matches key/hash.  If there is no such cache entry, return a
@@ -181,11 +264,19 @@ class LRUHandleTable {

  void Resize();

+  // Number of hash bits (upper because lower bits used for sharding)
+  // used for table index. Length == 1 << length_bits_
+  int length_bits_;
+
  // The table consists of an array of buckets where each bucket is
  // a linked list of cache entries that hash into the bucket.
-  LRUHandle** list_;
-  uint32_t length_;
+  std::unique_ptr<LRUHandle*[]> list_;
+
+  // Number of elements currently in the table.
  uint32_t elems_;
+
+  // Set from max_upper_hash_bits (see constructor).
+  const int max_length_bits_;
 };

 // A single shard of sharded cache.
@@ -193,12 +284,14 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {
 public:
  LRUCacheShard(size_t capacity, bool strict_capacity_limit,
                double high_pri_pool_ratio, bool use_adaptive_mutex,
-                CacheMetadataChargePolicy metadata_charge_policy);
+                CacheMetadataChargePolicy metadata_charge_policy,
+                int max_upper_hash_bits,
+                const std::shared_ptr<SecondaryCache>& secondary_cache);
  virtual ~LRUCacheShard() override = default;

  // Separate from constructor so caller can easily make an array of LRUCache
  // if current usage is more than new capacity, the function will attempt to
-  // free the needed space
+  // free the needed space.
  virtual void SetCapacity(size_t capacity) override;

  // Set the flag to reject insertion if cache if full.
@@ -209,14 +302,37 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {

  // Like Cache methods, but with an extra "hash" parameter.
  virtual Status Insert(const Slice& key, uint32_t hash, void* value,
-                        size_t charge,
-                        void (*deleter)(const Slice& key, void* value),
+                        size_t charge, Cache::DeleterFn deleter,
                        Cache::Handle** handle,
-                        Cache::Priority priority) override;
-  virtual Cache::Handle* Lookup(const Slice& key, uint32_t hash) override;
+                        Cache::Priority priority) override {
+    return Insert(key, hash, value, charge, deleter, nullptr, handle, priority);
+  }
+  virtual Status Insert(const Slice& key, uint32_t hash, void* value,
+                        const Cache::CacheItemHelper* helper, size_t charge,
+                        Cache::Handle** handle,
+                        Cache::Priority priority) override {
+    assert(helper);
+    return Insert(key, hash, value, charge, nullptr, helper, handle, priority);
+  }
+  // If helper_cb is null, the values of the following arguments don't matter.
+  virtual Cache::Handle* Lookup(const Slice& key, uint32_t hash,
+                                const ShardedCache::CacheItemHelper* helper,
+                                const ShardedCache::CreateCallback& create_cb,
+                                ShardedCache::Priority priority, bool wait,
+                                Statistics* stats) override;
+  virtual Cache::Handle* Lookup(const Slice& key, uint32_t hash) override {
+    return Lookup(key, hash, nullptr, nullptr, Cache::Priority::LOW, true,
+                  nullptr);
+  }
+  virtual bool Release(Cache::Handle* handle, bool /*useful*/,
+                       bool erase_if_last_ref) override {
+    return Release(handle, erase_if_last_ref);
+  }
+  virtual bool IsReady(Cache::Handle* /*handle*/) override;
+  virtual void Wait(Cache::Handle* /*handle*/) override {}
  virtual bool Ref(Cache::Handle* handle) override;
  virtual bool Release(Cache::Handle* handle,
-                       bool force_erase = false) override;
+                       bool erase_if_last_ref = false) override;
  virtual void Erase(const Slice& key, uint32_t hash) override;

  // Although in some platforms the update of size_t is atomic, to make sure
@@ -226,8 +342,10 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {
  virtual size_t GetUsage() const override;
  virtual size_t GetPinnedUsage() const override;

-  virtual void ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                                      bool thread_safe) override;
+  virtual void ApplyToSomeEntries(
+      const std::function<void(const Slice& key, void* value, size_t charge,
+                               DeleterFn deleter)>& callback,
+      uint32_t average_entries_per_lock, uint32_t* state) override;

  virtual void EraseUnRefEntries() override;

@@ -235,14 +353,32 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {

  void TEST_GetLRUList(LRUHandle** lru, LRUHandle** lru_low_pri);

-  //  Retrieves number of elements in LRU, for unit test purpose only
-  //  not threadsafe
+  //  Retrieves number of elements in LRU, for unit test purpose only.
+  //  Not threadsafe.
  size_t TEST_GetLRUSize();

  //  Retrieves high pri pool ratio
  double GetHighPriPoolRatio();

 private:
+  friend class LRUCache;
+  // Insert an item into the hash table and, if handle is null, insert into
+  // the LRU list. Older items are evicted as necessary. If the cache is full
+  // and free_handle_on_fail is true, the item is deleted and handle is set to
+  // nullptr.
+  Status InsertItem(LRUHandle* item, Cache::Handle** handle,
+                    bool free_handle_on_fail);
+  Status Insert(const Slice& key, uint32_t hash, void* value, size_t charge,
+                DeleterFn deleter, const Cache::CacheItemHelper* helper,
+                Cache::Handle** handle, Cache::Priority priority);
+  // Promote an item looked up from the secondary cache to the LRU cache. The
+  // item is only inserted into the hash table and not the LRU list, and only
+  // if the cache is not at full capacity, as is the case during Insert.  The
+  // caller should hold a reference on the LRUHandle. When the caller releases
+  // the last reference, the item is added to the LRU list.
+  // The item is promoted to the high pri or low pri pool as specified by the
+  // caller in Lookup.
+  void Promote(LRUHandle* e);
  void LRU_Remove(LRUHandle* e);
  void LRU_Insert(LRUHandle* e);

@@ -253,7 +389,7 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {
  // Free some space following strict LRU policy until enough space
  // to hold (usage_ + charge) is freed or the lru list is empty
  // This function is not thread safe - it needs to be executed while
-  // holding the mutex_
+  // holding the mutex_.
  void EvictFromLRU(size_t charge, autovector<LRUHandle*>* deleted);

  // Initialized before use.
@@ -293,16 +429,18 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {
  // ------------vvvvvvvvvvvvv-----------
  LRUHandleTable table_;

-  // Memory size for entries residing in the cache
+  // Memory size for entries residing in the cache.
  size_t usage_;

-  // Memory size for entries residing only in the LRU list
+  // Memory size for entries residing only in the LRU list.
  size_t lru_usage_;

  // mutex_ protects the following state.
  // We don't count mutex_ as the cache's internal state so semantically we
  // don't mind mutex_ invoking the non-const actions.
  mutable port::Mutex mutex_;
+
+  std::shared_ptr<SecondaryCache> secondary_cache_;
 };

 class LRUCache
@@ -316,24 +454,28 @@ class LRUCache
           std::shared_ptr<MemoryAllocator> memory_allocator = nullptr,
           bool use_adaptive_mutex = kDefaultToAdaptiveMutex,
           CacheMetadataChargePolicy metadata_charge_policy =
-               kDontChargeCacheMetadata);
+               kDontChargeCacheMetadata,
+           const std::shared_ptr<SecondaryCache>& secondary_cache = nullptr);
  virtual ~LRUCache();
  virtual const char* Name() const override { return "LRUCache"; }
-  virtual CacheShard* GetShard(int shard) override;
-  virtual const CacheShard* GetShard(int shard) const override;
+  virtual CacheShard* GetShard(uint32_t shard) override;
+  virtual const CacheShard* GetShard(uint32_t shard) const override;
  virtual void* Value(Handle* handle) override;
  virtual size_t GetCharge(Handle* handle) const override;
  virtual uint32_t GetHash(Handle* handle) const override;
+  virtual DeleterFn GetDeleter(Handle* handle) const override;
  virtual void DisownData() override;
+  virtual void WaitAll(std::vector<Handle*>& handles) override;

-  //  Retrieves number of elements in LRU, for unit test purpose only
+  //  Retrieves number of elements in LRU, for unit test purpose only.
  size_t TEST_GetLRUSize();
-  //  Retrieves high pri pool ratio
+  //  Retrieves high pri pool ratio.
  double GetHighPriPoolRatio();

 private:
  LRUCacheShard* shards_ = nullptr;
  int num_shards_ = 0;
+  std::shared_ptr<SecondaryCache> secondary_cache_;
 };

 }  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,168 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "cache/lru_secondary_cache.h"
+
+#include <memory>
+
+#include "memory/memory_allocator.h"
+#include "util/compression.h"
+#include "util/string_util.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+namespace {
+
+void DeletionCallback(const Slice& /*key*/, void* obj) {
+  delete reinterpret_cast<CacheAllocationPtr*>(obj);
+  obj = nullptr;
+}
+
+}  // namespace
+
+LRUSecondaryCache::LRUSecondaryCache(
+    size_t capacity, int num_shard_bits, bool strict_capacity_limit,
+    double high_pri_pool_ratio,
+    std::shared_ptr<MemoryAllocator> memory_allocator, bool use_adaptive_mutex,
+    CacheMetadataChargePolicy metadata_charge_policy,
+    CompressionType compression_type, uint32_t compress_format_version)
+    : cache_options_(capacity, num_shard_bits, strict_capacity_limit,
+                     high_pri_pool_ratio, memory_allocator, use_adaptive_mutex,
+                     metadata_charge_policy, compression_type,
+                     compress_format_version) {
+  cache_ = NewLRUCache(capacity, num_shard_bits, strict_capacity_limit,
+                       high_pri_pool_ratio, memory_allocator,
+                       use_adaptive_mutex, metadata_charge_policy);
+}
+
+LRUSecondaryCache::~LRUSecondaryCache() { cache_.reset(); }
+
+std::unique_ptr<SecondaryCacheResultHandle> LRUSecondaryCache::Lookup(
+    const Slice& key, const Cache::CreateCallback& create_cb, bool /*wait*/) {
+  std::unique_ptr<SecondaryCacheResultHandle> handle;
+  Cache::Handle* lru_handle = cache_->Lookup(key);
+  if (lru_handle == nullptr) {
+    return handle;
+  }
+
+  CacheAllocationPtr* ptr =
+      reinterpret_cast<CacheAllocationPtr*>(cache_->Value(lru_handle));
+  void* value = nullptr;
+  size_t charge = 0;
+  Status s;
+
+  if (cache_options_.compression_type == kNoCompression) {
+    s = create_cb(ptr->get(), cache_->GetCharge(lru_handle), &value, &charge);
+  } else {
+    UncompressionContext uncompression_context(cache_options_.compression_type);
+    UncompressionInfo uncompression_info(uncompression_context,
+                                         UncompressionDict::GetEmptyDict(),
+                                         cache_options_.compression_type);
+
+    size_t uncompressed_size = 0;
+    CacheAllocationPtr uncompressed;
+    uncompressed = UncompressData(
+        uncompression_info, (char*)ptr->get(), cache_->GetCharge(lru_handle),
+        &uncompressed_size, cache_options_.compress_format_version,
+        cache_options_.memory_allocator.get());
+
+    if (!uncompressed) {
+      cache_->Release(lru_handle, true);
+      return handle;
+    }
+    s = create_cb(uncompressed.get(), uncompressed_size, &value, &charge);
+  }
+
+  if (!s.ok()) {
+    cache_->Release(lru_handle, true);
+    return handle;
+  }
+
+  handle.reset(new LRUSecondaryCacheResultHandle(value, charge));
+  cache_->Release(lru_handle);
+  return handle;
+}
+
+Status LRUSecondaryCache::Insert(const Slice& key, void* value,
+                                 const Cache::CacheItemHelper* helper) {
+  size_t size = (*helper->size_cb)(value);
+  CacheAllocationPtr ptr =
+      AllocateBlock(size, cache_options_.memory_allocator.get());
+
+  Status s = (*helper->saveto_cb)(value, 0, size, ptr.get());
+  if (!s.ok()) {
+    return s;
+  }
+  Slice val(ptr.get(), size);
+
+  std::string compressed_val;
+  if (cache_options_.compression_type != kNoCompression) {
+    CompressionOptions compression_opts;
+    CompressionContext compression_context(cache_options_.compression_type);
+    uint64_t sample_for_compression = 0;
+    CompressionInfo compression_info(
+        compression_opts, compression_context, CompressionDict::GetEmptyDict(),
+        cache_options_.compression_type, sample_for_compression);
+
+    bool success =
+        CompressData(val, compression_info,
+                     cache_options_.compress_format_version, &compressed_val);
+
+    if (!success) {
+      return Status::Corruption("Error compressing value.");
+    }
+
+    val = Slice(compressed_val);
+    size = compressed_val.size();
+    ptr = AllocateBlock(size, cache_options_.memory_allocator.get());
+    memcpy(ptr.get(), compressed_val.data(), size);
+  }
+
+  CacheAllocationPtr* buf = new CacheAllocationPtr(std::move(ptr));
+
+  return cache_->Insert(key, buf, size, DeletionCallback);
+}
+
+void LRUSecondaryCache::Erase(const Slice& key) { cache_->Erase(key); }
+
+std::string LRUSecondaryCache::GetPrintableOptions() const {
+  std::string ret;
+  ret.reserve(20000);
+  const int kBufferSize = 200;
+  char buffer[kBufferSize];
+  ret.append(cache_->GetPrintableOptions());
+  snprintf(buffer, kBufferSize, "    compression_type : %s\n",
+           CompressionTypeToString(cache_options_.compression_type).c_str());
+  ret.append(buffer);
+  snprintf(buffer, kBufferSize, "    compression_type : %d\n",
+           cache_options_.compress_format_version);
+  ret.append(buffer);
+  return ret;
+}
+
+std::shared_ptr<SecondaryCache> NewLRUSecondaryCache(
+    size_t capacity, int num_shard_bits, bool strict_capacity_limit,
+    double high_pri_pool_ratio,
+    std::shared_ptr<MemoryAllocator> memory_allocator, bool use_adaptive_mutex,
+    CacheMetadataChargePolicy metadata_charge_policy,
+    CompressionType compression_type, uint32_t compress_format_version) {
+  return std::make_shared<LRUSecondaryCache>(
+      capacity, num_shard_bits, strict_capacity_limit, high_pri_pool_ratio,
+      memory_allocator, use_adaptive_mutex, metadata_charge_policy,
+      compression_type, compress_format_version);
+}
+
+std::shared_ptr<SecondaryCache> NewLRUSecondaryCache(
+    const LRUSecondaryCacheOptions& opts) {
+  // The secondary_cache is disabled for this LRUCache instance.
+  assert(opts.secondary_cache == nullptr);
+  return NewLRUSecondaryCache(
+      opts.capacity, opts.num_shard_bits, opts.strict_capacity_limit,
+      opts.high_pri_pool_ratio, opts.memory_allocator, opts.use_adaptive_mutex,
+      opts.metadata_charge_policy, opts.compression_type,
+      opts.compress_format_version);
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,85 @@
+// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <memory>
+
+#include "cache/lru_cache.h"
+#include "memory/memory_allocator.h"
+#include "rocksdb/secondary_cache.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/status.h"
+#include "util/compression.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class LRUSecondaryCacheResultHandle : public SecondaryCacheResultHandle {
+ public:
+  LRUSecondaryCacheResultHandle(void* value, size_t size)
+      : value_(value), size_(size) {}
+  virtual ~LRUSecondaryCacheResultHandle() override = default;
+
+  LRUSecondaryCacheResultHandle(const LRUSecondaryCacheResultHandle&) = delete;
+  LRUSecondaryCacheResultHandle& operator=(
+      const LRUSecondaryCacheResultHandle&) = delete;
+
+  bool IsReady() override { return true; }
+
+  void Wait() override {}
+
+  void* Value() override { return value_; }
+
+  size_t Size() override { return size_; }
+
+ private:
+  void* value_;
+  size_t size_;
+};
+
+// The LRUSecondaryCache is a concrete implementation of
+// rocksdb::SecondaryCache.
+//
+// Users can also cast a pointer to it and call methods on
+// it directly, especially custom methods that may be added
+// in the future.  For example -
+// std::unique_ptr<rocksdb::SecondaryCache> cache =
+//      NewLRUSecondaryCache(opts);
+// static_cast<LRUSecondaryCache*>(cache.get())->Erase(key);
+
+class LRUSecondaryCache : public SecondaryCache {
+ public:
+  LRUSecondaryCache(
+      size_t capacity, int num_shard_bits, bool strict_capacity_limit,
+      double high_pri_pool_ratio,
+      std::shared_ptr<MemoryAllocator> memory_allocator = nullptr,
+      bool use_adaptive_mutex = kDefaultToAdaptiveMutex,
+      CacheMetadataChargePolicy metadata_charge_policy =
+          kDontChargeCacheMetadata,
+      CompressionType compression_type = CompressionType::kLZ4Compression,
+      uint32_t compress_format_version = 2);
+  virtual ~LRUSecondaryCache() override;
+
+  const char* Name() const override { return "LRUSecondaryCache"; }
+
+  Status Insert(const Slice& key, void* value,
+                const Cache::CacheItemHelper* helper) override;
+
+  std::unique_ptr<SecondaryCacheResultHandle> Lookup(
+      const Slice& key, const Cache::CreateCallback& create_cb,
+      bool /*wait*/) override;
+
+  void Erase(const Slice& key) override;
+
+  void WaitAll(std::vector<SecondaryCacheResultHandle*> /*handles*/) override {}
+
+  std::string GetPrintableOptions() const override;
+
+ private:
+  std::shared_ptr<Cache> cache_;
+  LRUSecondaryCacheOptions cache_options_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,597 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "cache/lru_secondary_cache.h"
+
+#include <algorithm>
+#include <cstdint>
+
+#include "memory/jemalloc_nodump_allocator.h"
+#include "memory/memory_allocator.h"
+#include "test_util/testharness.h"
+#include "test_util/testutil.h"
+#include "util/compression.h"
+#include "util/random.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class LRUSecondaryCacheTest : public testing::Test {
+ public:
+  LRUSecondaryCacheTest() : fail_create_(false) {}
+  ~LRUSecondaryCacheTest() {}
+
+ protected:
+  class TestItem {
+   public:
+    TestItem(const char* buf, size_t size) : buf_(new char[size]), size_(size) {
+      memcpy(buf_.get(), buf, size);
+    }
+    ~TestItem() {}
+
+    char* Buf() { return buf_.get(); }
+    size_t Size() { return size_; }
+
+   private:
+    std::unique_ptr<char[]> buf_;
+    size_t size_;
+  };
+
+  static size_t SizeCallback(void* obj) {
+    return reinterpret_cast<TestItem*>(obj)->Size();
+  }
+
+  static Status SaveToCallback(void* from_obj, size_t from_offset,
+                               size_t length, void* out) {
+    TestItem* item = reinterpret_cast<TestItem*>(from_obj);
+    const char* buf = item->Buf();
+    EXPECT_EQ(length, item->Size());
+    EXPECT_EQ(from_offset, 0);
+    memcpy(out, buf, length);
+    return Status::OK();
+  }
+
+  static void DeletionCallback(const Slice& /*key*/, void* obj) {
+    delete reinterpret_cast<TestItem*>(obj);
+    obj = nullptr;
+  }
+
+  static Cache::CacheItemHelper helper_;
+
+  static Status SaveToCallbackFail(void* /*obj*/, size_t /*offset*/,
+                                   size_t /*size*/, void* /*out*/) {
+    return Status::NotSupported();
+  }
+
+  static Cache::CacheItemHelper helper_fail_;
+
+  Cache::CreateCallback test_item_creator = [&](const void* buf, size_t size,
+                                                void** out_obj,
+                                                size_t* charge) -> Status {
+    if (fail_create_) {
+      return Status::NotSupported();
+    }
+    *out_obj = reinterpret_cast<void*>(new TestItem((char*)buf, size));
+    *charge = size;
+    return Status::OK();
+  };
+
+  void SetFailCreate(bool fail) { fail_create_ = fail; }
+
+  void BasicTest(bool sec_cache_is_compressed, bool use_jemalloc) {
+    LRUSecondaryCacheOptions opts;
+    opts.capacity = 2048;
+    opts.num_shard_bits = 0;
+    opts.metadata_charge_policy = kDontChargeCacheMetadata;
+
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    if (use_jemalloc) {
+      JemallocAllocatorOptions jopts;
+      std::shared_ptr<MemoryAllocator> allocator;
+      std::string msg;
+      if (JemallocNodumpAllocator::IsSupported(&msg)) {
+        Status s = NewJemallocNodumpAllocator(jopts, &allocator);
+        if (s.ok()) {
+          opts.memory_allocator = allocator;
+        }
+      } else {
+        ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
+      }
+    }
+    std::shared_ptr<SecondaryCache> cache = NewLRUSecondaryCache(opts);
+
+    // Lookup an non-existent key.
+    std::unique_ptr<SecondaryCacheResultHandle> handle0 =
+        cache->Lookup("k0", test_item_creator, true);
+    ASSERT_EQ(handle0, nullptr);
+
+    Random rnd(301);
+    // Insert and Lookup the first item.
+    std::string str1;
+    test::CompressibleString(&rnd, 0.25, 1000, &str1);
+    TestItem item1(str1.data(), str1.length());
+    ASSERT_OK(cache->Insert("k1", &item1, &LRUSecondaryCacheTest::helper_));
+    std::unique_ptr<SecondaryCacheResultHandle> handle1 =
+        cache->Lookup("k1", test_item_creator, true);
+    ASSERT_NE(handle1, nullptr);
+    // delete reinterpret_cast<TestItem*>(handle1->Value());
+    std::unique_ptr<TestItem> val1 =
+        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle1->Value()));
+    ASSERT_NE(val1, nullptr);
+    ASSERT_EQ(memcmp(val1->Buf(), item1.Buf(), item1.Size()), 0);
+
+    // Insert and Lookup the second item.
+    std::string str2;
+    test::CompressibleString(&rnd, 0.5, 1000, &str2);
+    TestItem item2(str2.data(), str2.length());
+    ASSERT_OK(cache->Insert("k2", &item2, &LRUSecondaryCacheTest::helper_));
+    std::unique_ptr<SecondaryCacheResultHandle> handle2 =
+        cache->Lookup("k2", test_item_creator, true);
+    ASSERT_NE(handle2, nullptr);
+    std::unique_ptr<TestItem> val2 =
+        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle2->Value()));
+    ASSERT_NE(val2, nullptr);
+    ASSERT_EQ(memcmp(val2->Buf(), item2.Buf(), item2.Size()), 0);
+
+    // Lookup the first item again to make sure it is still in the cache.
+    std::unique_ptr<SecondaryCacheResultHandle> handle1_1 =
+        cache->Lookup("k1", test_item_creator, true);
+    ASSERT_NE(handle1_1, nullptr);
+    std::unique_ptr<TestItem> val1_1 =
+        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle1_1->Value()));
+    ASSERT_NE(val1_1, nullptr);
+    ASSERT_EQ(memcmp(val1_1->Buf(), item1.Buf(), item1.Size()), 0);
+
+    std::vector<SecondaryCacheResultHandle*> handles = {handle1.get(),
+                                                        handle2.get()};
+    cache->WaitAll(handles);
+
+    cache->Erase("k1");
+    handle1 = cache->Lookup("k1", test_item_creator, true);
+    ASSERT_EQ(handle1, nullptr);
+
+    cache.reset();
+  }
+
+  void FailsTest(bool sec_cache_is_compressed) {
+    LRUSecondaryCacheOptions secondary_cache_opts;
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    secondary_cache_opts.capacity = 1100;
+    secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+    std::shared_ptr<SecondaryCache> cache =
+        NewLRUSecondaryCache(secondary_cache_opts);
+
+    // Insert and Lookup the first item.
+    Random rnd(301);
+    std::string str1(rnd.RandomString(1000));
+    TestItem item1(str1.data(), str1.length());
+    ASSERT_OK(cache->Insert("k1", &item1, &LRUSecondaryCacheTest::helper_));
+    std::unique_ptr<SecondaryCacheResultHandle> handle1 =
+        cache->Lookup("k1", test_item_creator, true);
+    ASSERT_NE(handle1, nullptr);
+    std::unique_ptr<TestItem> val1 =
+        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle1->Value()));
+    ASSERT_NE(val1, nullptr);
+    ASSERT_EQ(memcmp(val1->Buf(), item1.Buf(), item1.Size()), 0);
+
+    // Insert and Lookup the second item.
+    std::string str2(rnd.RandomString(200));
+    TestItem item2(str2.data(), str2.length());
+    // k1 is evicted.
+    ASSERT_OK(cache->Insert("k2", &item2, &LRUSecondaryCacheTest::helper_));
+    std::unique_ptr<SecondaryCacheResultHandle> handle1_1 =
+        cache->Lookup("k1", test_item_creator, true);
+    ASSERT_EQ(handle1_1, nullptr);
+    std::unique_ptr<SecondaryCacheResultHandle> handle2 =
+        cache->Lookup("k2", test_item_creator, true);
+    ASSERT_NE(handle2, nullptr);
+    std::unique_ptr<TestItem> val2 =
+        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle2->Value()));
+    ASSERT_NE(val2, nullptr);
+    ASSERT_EQ(memcmp(val2->Buf(), item2.Buf(), item2.Size()), 0);
+
+    // Create Fails.
+    SetFailCreate(true);
+    std::unique_ptr<SecondaryCacheResultHandle> handle2_1 =
+        cache->Lookup("k2", test_item_creator, true);
+    ASSERT_EQ(handle2_1, nullptr);
+
+    // Save Fails.
+    std::string str3 = rnd.RandomString(10);
+    TestItem item3(str3.data(), str3.length());
+    ASSERT_NOK(
+        cache->Insert("k3", &item3, &LRUSecondaryCacheTest::helper_fail_));
+
+    cache.reset();
+  }
+
+  void BasicIntegrationTest(bool sec_cache_is_compressed) {
+    LRUSecondaryCacheOptions secondary_cache_opts;
+
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    secondary_cache_opts.capacity = 2300;
+    secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+    std::shared_ptr<SecondaryCache> secondary_cache =
+        NewLRUSecondaryCache(secondary_cache_opts);
+    LRUCacheOptions lru_cache_opts(1024, 0, false, 0.5, nullptr,
+                                   kDefaultToAdaptiveMutex,
+                                   kDontChargeCacheMetadata);
+    lru_cache_opts.secondary_cache = secondary_cache;
+    std::shared_ptr<Cache> cache = NewLRUCache(lru_cache_opts);
+    std::shared_ptr<Statistics> stats = CreateDBStatistics();
+
+    Random rnd(301);
+
+    std::string str1 = rnd.RandomString(1010);
+    std::string str1_clone{str1};
+    TestItem* item1 = new TestItem(str1.data(), str1.length());
+    ASSERT_OK(cache->Insert("k1", item1, &LRUSecondaryCacheTest::helper_,
+                            str1.length()));
+
+    std::string str2 = rnd.RandomString(1020);
+    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    // After Insert, lru cache contains k2 and secondary cache contains k1.
+    ASSERT_OK(cache->Insert("k2", item2, &LRUSecondaryCacheTest::helper_,
+                            str2.length()));
+
+    std::string str3 = rnd.RandomString(1020);
+    TestItem* item3 = new TestItem(str3.data(), str3.length());
+    // After Insert, lru cache contains k3 and secondary cache contains k1 and
+    // k2
+    ASSERT_OK(cache->Insert("k3", item3, &LRUSecondaryCacheTest::helper_,
+                            str3.length()));
+
+    Cache::Handle* handle;
+    handle =
+        cache->Lookup("k3", &LRUSecondaryCacheTest::helper_, test_item_creator,
+                      Cache::Priority::LOW, true, stats.get());
+    ASSERT_NE(handle, nullptr);
+    TestItem* val3 = static_cast<TestItem*>(cache->Value(handle));
+    ASSERT_NE(val3, nullptr);
+    ASSERT_EQ(memcmp(val3->Buf(), item3->Buf(), item3->Size()), 0);
+    cache->Release(handle);
+
+    // Lookup an non-existent key.
+    handle =
+        cache->Lookup("k0", &LRUSecondaryCacheTest::helper_, test_item_creator,
+                      Cache::Priority::LOW, true, stats.get());
+    ASSERT_EQ(handle, nullptr);
+
+    // This Lookup should promote k1 and demote k3, so k2 is evicted from the
+    // secondary cache. The lru cache contains k1 and secondary cache contains
+    // k3. item1 was Free(), so it cannot be compared against the item1.
+    handle =
+        cache->Lookup("k1", &LRUSecondaryCacheTest::helper_, test_item_creator,
+                      Cache::Priority::LOW, true, stats.get());
+    ASSERT_NE(handle, nullptr);
+    TestItem* val1_1 = static_cast<TestItem*>(cache->Value(handle));
+    ASSERT_NE(val1_1, nullptr);
+    ASSERT_EQ(memcmp(val1_1->Buf(), str1_clone.data(), str1_clone.size()), 0);
+    cache->Release(handle);
+
+    handle =
+        cache->Lookup("k2", &LRUSecondaryCacheTest::helper_, test_item_creator,
+                      Cache::Priority::LOW, true, stats.get());
+    ASSERT_EQ(handle, nullptr);
+
+    cache.reset();
+    secondary_cache.reset();
+  }
+
+  void BasicIntegrationFailTest(bool sec_cache_is_compressed) {
+    LRUSecondaryCacheOptions secondary_cache_opts;
+
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    secondary_cache_opts.capacity = 2048;
+    secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+    std::shared_ptr<SecondaryCache> secondary_cache =
+        NewLRUSecondaryCache(secondary_cache_opts);
+
+    LRUCacheOptions opts(1024, 0, false, 0.5, nullptr, kDefaultToAdaptiveMutex,
+                         kDontChargeCacheMetadata);
+    opts.secondary_cache = secondary_cache;
+    std::shared_ptr<Cache> cache = NewLRUCache(opts);
+
+    Random rnd(301);
+    std::string str1 = rnd.RandomString(1020);
+    auto item1 =
+        std::unique_ptr<TestItem>(new TestItem(str1.data(), str1.length()));
+    ASSERT_NOK(cache->Insert("k1", item1.get(), nullptr, str1.length()));
+    ASSERT_OK(cache->Insert("k1", item1.get(), &LRUSecondaryCacheTest::helper_,
+                            str1.length()));
+    item1.release();  // Appease clang-analyze "potential memory leak"
+
+    Cache::Handle* handle;
+    handle = cache->Lookup("k2", nullptr, test_item_creator,
+                           Cache::Priority::LOW, true);
+    ASSERT_EQ(handle, nullptr);
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, false);
+    ASSERT_EQ(handle, nullptr);
+
+    cache.reset();
+    secondary_cache.reset();
+  }
+
+  void IntegrationSaveFailTest(bool sec_cache_is_compressed) {
+    LRUSecondaryCacheOptions secondary_cache_opts;
+
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    secondary_cache_opts.capacity = 2048;
+    secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+
+    std::shared_ptr<SecondaryCache> secondary_cache =
+        NewLRUSecondaryCache(secondary_cache_opts);
+
+    LRUCacheOptions opts(1024, 0, false, 0.5, nullptr, kDefaultToAdaptiveMutex,
+                         kDontChargeCacheMetadata);
+    opts.secondary_cache = secondary_cache;
+    std::shared_ptr<Cache> cache = NewLRUCache(opts);
+
+    Random rnd(301);
+    std::string str1 = rnd.RandomString(1020);
+    TestItem* item1 = new TestItem(str1.data(), str1.length());
+    ASSERT_OK(cache->Insert("k1", item1, &LRUSecondaryCacheTest::helper_fail_,
+                            str1.length()));
+    std::string str2 = rnd.RandomString(1020);
+    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    // k1 should be demoted to the secondary cache.
+    ASSERT_OK(cache->Insert("k2", item2, &LRUSecondaryCacheTest::helper_fail_,
+                            str2.length()));
+
+    Cache::Handle* handle;
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_fail_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle, nullptr);
+    cache->Release(handle);
+    // This lookup should fail, since k1 demotion would have failed
+    handle = cache->Lookup("k1", &LRUSecondaryCacheTest::helper_fail_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_EQ(handle, nullptr);
+    // Since k1 didn't get promoted, k2 should still be in cache
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_fail_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle, nullptr);
+    cache->Release(handle);
+
+    cache.reset();
+    secondary_cache.reset();
+  }
+
+  void IntegrationCreateFailTest(bool sec_cache_is_compressed) {
+    LRUSecondaryCacheOptions secondary_cache_opts;
+
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    secondary_cache_opts.capacity = 2048;
+    secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+
+    std::shared_ptr<SecondaryCache> secondary_cache =
+        NewLRUSecondaryCache(secondary_cache_opts);
+
+    LRUCacheOptions opts(1024, 0, false, 0.5, nullptr, kDefaultToAdaptiveMutex,
+                         kDontChargeCacheMetadata);
+    opts.secondary_cache = secondary_cache;
+    std::shared_ptr<Cache> cache = NewLRUCache(opts);
+
+    Random rnd(301);
+    std::string str1 = rnd.RandomString(1020);
+    TestItem* item1 = new TestItem(str1.data(), str1.length());
+    ASSERT_OK(cache->Insert("k1", item1, &LRUSecondaryCacheTest::helper_,
+                            str1.length()));
+
+    std::string str2 = rnd.RandomString(1020);
+    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    // k1 should be demoted to the secondary cache.
+    ASSERT_OK(cache->Insert("k2", item2, &LRUSecondaryCacheTest::helper_,
+                            str2.length()));
+
+    Cache::Handle* handle;
+    SetFailCreate(true);
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle, nullptr);
+    cache->Release(handle);
+    // This lookup should fail, since k1 creation would have failed
+    handle = cache->Lookup("k1", &LRUSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_EQ(handle, nullptr);
+    // Since k1 didn't get promoted, k2 should still be in cache
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle, nullptr);
+    cache->Release(handle);
+
+    cache.reset();
+    secondary_cache.reset();
+  }
+
+  void IntegrationFullCapacityTest(bool sec_cache_is_compressed) {
+    LRUSecondaryCacheOptions secondary_cache_opts;
+
+    if (sec_cache_is_compressed) {
+      if (!LZ4_Supported()) {
+        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+      }
+    } else {
+      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
+    }
+
+    secondary_cache_opts.capacity = 2048;
+    secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+
+    std::shared_ptr<SecondaryCache> secondary_cache =
+        NewLRUSecondaryCache(secondary_cache_opts);
+
+    LRUCacheOptions opts(1024, 0, /*_strict_capacity_limit=*/true, 0.5, nullptr,
+                         kDefaultToAdaptiveMutex, kDontChargeCacheMetadata);
+    opts.secondary_cache = secondary_cache;
+    std::shared_ptr<Cache> cache = NewLRUCache(opts);
+
+    Random rnd(301);
+    std::string str1 = rnd.RandomString(1020);
+    TestItem* item1 = new TestItem(str1.data(), str1.length());
+    ASSERT_OK(cache->Insert("k1", item1, &LRUSecondaryCacheTest::helper_,
+                            str1.length()));
+    std::string str2 = rnd.RandomString(1020);
+    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    // k1 should be demoted to the secondary cache.
+    ASSERT_OK(cache->Insert("k2", item2, &LRUSecondaryCacheTest::helper_,
+                            str2.length()));
+
+    Cache::Handle* handle;
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle, nullptr);
+    // k1 promotion should fail due to the block cache being at capacity,
+    // but the lookup should still succeed
+    Cache::Handle* handle2;
+    handle2 = cache->Lookup("k1", &LRUSecondaryCacheTest::helper_,
+                            test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle2, nullptr);
+    // Since k1 didn't get inserted, k2 should still be in cache
+    cache->Release(handle);
+    cache->Release(handle2);
+    handle = cache->Lookup("k2", &LRUSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true);
+    ASSERT_NE(handle, nullptr);
+    cache->Release(handle);
+
+    cache.reset();
+    secondary_cache.reset();
+  }
+
+ private:
+  bool fail_create_;
+};
+
+Cache::CacheItemHelper LRUSecondaryCacheTest::helper_(
+    LRUSecondaryCacheTest::SizeCallback, LRUSecondaryCacheTest::SaveToCallback,
+    LRUSecondaryCacheTest::DeletionCallback);
+
+Cache::CacheItemHelper LRUSecondaryCacheTest::helper_fail_(
+    LRUSecondaryCacheTest::SizeCallback,
+    LRUSecondaryCacheTest::SaveToCallbackFail,
+    LRUSecondaryCacheTest::DeletionCallback);
+
+TEST_F(LRUSecondaryCacheTest, BasicTestWithNoCompression) {
+  BasicTest(false, false);
+}
+
+TEST_F(LRUSecondaryCacheTest, BasicTestWithMemoryAllocatorAndNoCompression) {
+  BasicTest(false, true);
+}
+
+TEST_F(LRUSecondaryCacheTest, BasicTestWithCompression) {
+  BasicTest(true, false);
+}
+
+TEST_F(LRUSecondaryCacheTest, BasicTestWithMemoryAllocatorAndCompression) {
+  BasicTest(true, true);
+}
+
+TEST_F(LRUSecondaryCacheTest, FailsTestWithNoCompression) { FailsTest(false); }
+
+TEST_F(LRUSecondaryCacheTest, FailsTestWithCompression) { FailsTest(true); }
+
+TEST_F(LRUSecondaryCacheTest, BasicIntegrationTestWithNoCompression) {
+  BasicIntegrationTest(false);
+}
+
+TEST_F(LRUSecondaryCacheTest, BasicIntegrationTestWithCompression) {
+  BasicIntegrationTest(true);
+}
+
+TEST_F(LRUSecondaryCacheTest, BasicIntegrationFailTestWithNoCompression) {
+  BasicIntegrationFailTest(false);
+}
+
+TEST_F(LRUSecondaryCacheTest, BasicIntegrationFailTestWithCompression) {
+  BasicIntegrationFailTest(true);
+}
+
+TEST_F(LRUSecondaryCacheTest, IntegrationSaveFailTestWithNoCompression) {
+  IntegrationSaveFailTest(false);
+}
+
+TEST_F(LRUSecondaryCacheTest, IntegrationSaveFailTestWithCompression) {
+  IntegrationSaveFailTest(true);
+}
+
+TEST_F(LRUSecondaryCacheTest, IntegrationCreateFailTestWithNoCompression) {
+  IntegrationCreateFailTest(false);
+}
+
+TEST_F(LRUSecondaryCacheTest, IntegrationCreateFailTestWithCompression) {
+  IntegrationCreateFailTest(true);
+}
+
+TEST_F(LRUSecondaryCacheTest, IntegrationFullCapacityTestWithNoCompression) {
+  IntegrationFullCapacityTest(false);
+}
+
+TEST_F(LRUSecondaryCacheTest, IntegrationFullCapacityTestWithCompression) {
+  IntegrationFullCapacityTest(true);
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -9,61 +9,110 @@

 #include "cache/sharded_cache.h"

-#include <string>
+#include <algorithm>
+#include <cstdint>
+#include <memory>

+#include "util/hash.h"
+#include "util/math.h"
 #include "util/mutexlock.h"

 namespace ROCKSDB_NAMESPACE {

+namespace {
+
+inline uint32_t HashSlice(const Slice& s) {
+  return Lower32of64(GetSliceNPHash64(s));
+}
+
+}  // namespace
+
 ShardedCache::ShardedCache(size_t capacity, int num_shard_bits,
                           bool strict_capacity_limit,
                           std::shared_ptr<MemoryAllocator> allocator)
    : Cache(std::move(allocator)),
-      num_shard_bits_(num_shard_bits),
+      shard_mask_((uint32_t{1} << num_shard_bits) - 1),
      capacity_(capacity),
      strict_capacity_limit_(strict_capacity_limit),
      last_id_(1) {}

 void ShardedCache::SetCapacity(size_t capacity) {
-  int num_shards = 1 << num_shard_bits_;
+  uint32_t num_shards = GetNumShards();
  const size_t per_shard = (capacity + (num_shards - 1)) / num_shards;
  MutexLock l(&capacity_mutex_);
-  for (int s = 0; s < num_shards; s++) {
+  for (uint32_t s = 0; s < num_shards; s++) {
    GetShard(s)->SetCapacity(per_shard);
  }
  capacity_ = capacity;
 }

 void ShardedCache::SetStrictCapacityLimit(bool strict_capacity_limit) {
-  int num_shards = 1 << num_shard_bits_;
+  uint32_t num_shards = GetNumShards();
  MutexLock l(&capacity_mutex_);
-  for (int s = 0; s < num_shards; s++) {
+  for (uint32_t s = 0; s < num_shards; s++) {
    GetShard(s)->SetStrictCapacityLimit(strict_capacity_limit);
  }
  strict_capacity_limit_ = strict_capacity_limit;
 }

 Status ShardedCache::Insert(const Slice& key, void* value, size_t charge,
-                            void (*deleter)(const Slice& key, void* value),
-                            Handle** handle, Priority priority) {
+                            DeleterFn deleter, Handle** handle,
+                            Priority priority) {
  uint32_t hash = HashSlice(key);
  return GetShard(Shard(hash))
      ->Insert(key, hash, value, charge, deleter, handle, priority);
 }

+Status ShardedCache::Insert(const Slice& key, void* value,
+                            const CacheItemHelper* helper, size_t charge,
+                            Handle** handle, Priority priority) {
+  uint32_t hash = HashSlice(key);
+  if (!helper) {
+    return Status::InvalidArgument();
+  }
+  return GetShard(Shard(hash))
+      ->Insert(key, hash, value, helper, charge, handle, priority);
+}
+
 Cache::Handle* ShardedCache::Lookup(const Slice& key, Statistics* /*stats*/) {
  uint32_t hash = HashSlice(key);
  return GetShard(Shard(hash))->Lookup(key, hash);
 }

+Cache::Handle* ShardedCache::Lookup(const Slice& key,
+                                    const CacheItemHelper* helper,
+                                    const CreateCallback& create_cb,
+                                    Priority priority, bool wait,
+                                    Statistics* stats) {
+  uint32_t hash = HashSlice(key);
+  return GetShard(Shard(hash))
+      ->Lookup(key, hash, helper, create_cb, priority, wait, stats);
+}
+
+bool ShardedCache::IsReady(Handle* handle) {
+  uint32_t hash = GetHash(handle);
+  return GetShard(Shard(hash))->IsReady(handle);
+}
+
+void ShardedCache::Wait(Handle* handle) {
+  uint32_t hash = GetHash(handle);
+  GetShard(Shard(hash))->Wait(handle);
+}
+
 bool ShardedCache::Ref(Handle* handle) {
  uint32_t hash = GetHash(handle);
  return GetShard(Shard(hash))->Ref(handle);
 }

-bool ShardedCache::Release(Handle* handle, bool force_erase) {
+bool ShardedCache::Release(Handle* handle, bool erase_if_last_ref) {
  uint32_t hash = GetHash(handle);
-  return GetShard(Shard(hash))->Release(handle, force_erase);
+  return GetShard(Shard(hash))->Release(handle, erase_if_last_ref);
+}
+
+bool ShardedCache::Release(Handle* handle, bool useful,
+                           bool erase_if_last_ref) {
+  uint32_t hash = GetHash(handle);
+  return GetShard(Shard(hash))->Release(handle, useful, erase_if_last_ref);
 }

 void ShardedCache::Erase(const Slice& key) {
@@ -87,9 +136,9 @@ bool ShardedCache::HasStrictCapacityLimit() const {

 size_t ShardedCache::GetUsage() const {
  // We will not lock the cache when getting the usage from shards.
-  int num_shards = 1 << num_shard_bits_;
+  uint32_t num_shards = GetNumShards();
  size_t usage = 0;
-  for (int s = 0; s < num_shards; s++) {
+  for (uint32_t s = 0; s < num_shards; s++) {
    usage += GetShard(s)->GetUsage();
  }
  return usage;
@@ -101,25 +150,42 @@ size_t ShardedCache::GetUsage(Handle* handle) const {

 size_t ShardedCache::GetPinnedUsage() const {
  // We will not lock the cache when getting the usage from shards.
-  int num_shards = 1 << num_shard_bits_;
+  uint32_t num_shards = GetNumShards();
  size_t usage = 0;
-  for (int s = 0; s < num_shards; s++) {
+  for (uint32_t s = 0; s < num_shards; s++) {
    usage += GetShard(s)->GetPinnedUsage();
  }
  return usage;
 }

-void ShardedCache::ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                                          bool thread_safe) {
-  int num_shards = 1 << num_shard_bits_;
-  for (int s = 0; s < num_shards; s++) {
-    GetShard(s)->ApplyToAllCacheEntries(callback, thread_safe);
-  }
+void ShardedCache::ApplyToAllEntries(
+    const std::function<void(const Slice& key, void* value, size_t charge,
+                             DeleterFn deleter)>& callback,
+    const ApplyToAllEntriesOptions& opts) {
+  uint32_t num_shards = GetNumShards();
+  // Iterate over part of each shard, rotating between shards, to
+  // minimize impact on latency of concurrent operations.
+  std::unique_ptr<uint32_t[]> states(new uint32_t[num_shards]{});
+
+  uint32_t aepl_in_32 = static_cast<uint32_t>(
+      std::min(size_t{UINT32_MAX}, opts.average_entries_per_lock));
+  aepl_in_32 = std::min(aepl_in_32, uint32_t{1});
+
+  bool remaining_work;
+  do {
+    remaining_work = false;
+    for (uint32_t s = 0; s < num_shards; s++) {
+      if (states[s] != UINT32_MAX) {
+        GetShard(s)->ApplyToSomeEntries(callback, aepl_in_32, &states[s]);
+        remaining_work |= states[s] != UINT32_MAX;
+      }
+    }
+  } while (remaining_work);
 }

 void ShardedCache::EraseUnRefEntries() {
-  int num_shards = 1 << num_shard_bits_;
-  for (int s = 0; s < num_shards; s++) {
+  uint32_t num_shards = GetNumShards();
+  for (uint32_t s = 0; s < num_shards; s++) {
    GetShard(s)->EraseUnRefEntries();
  }
 }
@@ -134,7 +200,8 @@ std::string ShardedCache::GetPrintableOptions() const {
    snprintf(buffer, kBufferSize, "    capacity : %" ROCKSDB_PRIszt "\n",
             capacity_);
    ret.append(buffer);
-    snprintf(buffer, kBufferSize, "    num_shard_bits : %d\n", num_shard_bits_);
+    snprintf(buffer, kBufferSize, "    num_shard_bits : %d\n",
+             GetNumShardBits());
    ret.append(buffer);
    snprintf(buffer, kBufferSize, "    strict_capacity_limit : %d\n",
             strict_capacity_limit_);
@@ -159,4 +226,8 @@ int GetDefaultCacheShardBits(size_t capacity) {
  return num_shard_bits;
 }

+int ShardedCache::GetNumShardBits() const { return BitsSetToOne(shard_mask_); }
+
+uint32_t ShardedCache::GetNumShards() const { return shard_mask_ + 1; }
+
 }  // namespace ROCKSDB_NAMESPACE
@@ -14,7 +14,6 @@

 #include "port/port.h"
 #include "rocksdb/cache.h"
-#include "util/hash.h"

 namespace ROCKSDB_NAMESPACE {

@@ -24,20 +23,38 @@ class CacheShard {
  CacheShard() = default;
  virtual ~CacheShard() = default;

+  using DeleterFn = Cache::DeleterFn;
  virtual Status Insert(const Slice& key, uint32_t hash, void* value,
-                        size_t charge,
-                        void (*deleter)(const Slice& key, void* value),
+                        size_t charge, DeleterFn deleter,
+                        Cache::Handle** handle, Cache::Priority priority) = 0;
+  virtual Status Insert(const Slice& key, uint32_t hash, void* value,
+                        const Cache::CacheItemHelper* helper, size_t charge,
                        Cache::Handle** handle, Cache::Priority priority) = 0;
  virtual Cache::Handle* Lookup(const Slice& key, uint32_t hash) = 0;
+  virtual Cache::Handle* Lookup(const Slice& key, uint32_t hash,
+                                const Cache::CacheItemHelper* helper,
+                                const Cache::CreateCallback& create_cb,
+                                Cache::Priority priority, bool wait,
+                                Statistics* stats) = 0;
+  virtual bool Release(Cache::Handle* handle, bool useful,
+                       bool erase_if_last_ref) = 0;
+  virtual bool IsReady(Cache::Handle* handle) = 0;
+  virtual void Wait(Cache::Handle* handle) = 0;
  virtual bool Ref(Cache::Handle* handle) = 0;
-  virtual bool Release(Cache::Handle* handle, bool force_erase = false) = 0;
+  virtual bool Release(Cache::Handle* handle, bool erase_if_last_ref) = 0;
  virtual void Erase(const Slice& key, uint32_t hash) = 0;
  virtual void SetCapacity(size_t capacity) = 0;
  virtual void SetStrictCapacityLimit(bool strict_capacity_limit) = 0;
  virtual size_t GetUsage() const = 0;
  virtual size_t GetPinnedUsage() const = 0;
-  virtual void ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                                      bool thread_safe) = 0;
+  // Handles iterating over roughly `average_entries_per_lock` entries, using
+  // `state` to somehow record where it last ended up. Caller initially uses
+  // *state == 0 and implementation sets *state = UINT32_MAX to indicate
+  // completion.
+  virtual void ApplyToSomeEntries(
+      const std::function<void(const Slice& key, void* value, size_t charge,
+                               DeleterFn deleter)>& callback,
+      uint32_t average_entries_per_lock, uint32_t* state) = 0;
  virtual void EraseUnRefEntries() = 0;
  virtual std::string GetPrintableOptions() const { return ""; }
  void set_metadata_charge_policy(
@@ -57,24 +74,31 @@ class ShardedCache : public Cache {
  ShardedCache(size_t capacity, int num_shard_bits, bool strict_capacity_limit,
               std::shared_ptr<MemoryAllocator> memory_allocator = nullptr);
  virtual ~ShardedCache() = default;
-  virtual const char* Name() const override = 0;
-  virtual CacheShard* GetShard(int shard) = 0;
-  virtual const CacheShard* GetShard(int shard) const = 0;
-  virtual void* Value(Handle* handle) override = 0;
-  virtual size_t GetCharge(Handle* handle) const override = 0;
+  virtual CacheShard* GetShard(uint32_t shard) = 0;
+  virtual const CacheShard* GetShard(uint32_t shard) const = 0;

  virtual uint32_t GetHash(Handle* handle) const = 0;
-  virtual void DisownData() override = 0;

  virtual void SetCapacity(size_t capacity) override;
  virtual void SetStrictCapacityLimit(bool strict_capacity_limit) override;

  virtual Status Insert(const Slice& key, void* value, size_t charge,
-                        void (*deleter)(const Slice& key, void* value),
-                        Handle** handle, Priority priority) override;
+                        DeleterFn deleter, Handle** handle,
+                        Priority priority) override;
+  virtual Status Insert(const Slice& key, void* value,
+                        const CacheItemHelper* helper, size_t chargge,
+                        Handle** handle = nullptr,
+                        Priority priority = Priority::LOW) override;
  virtual Handle* Lookup(const Slice& key, Statistics* stats) override;
+  virtual Handle* Lookup(const Slice& key, const CacheItemHelper* helper,
+                         const CreateCallback& create_cb, Priority priority,
+                         bool wait, Statistics* stats = nullptr) override;
+  virtual bool Release(Handle* handle, bool useful,
+                       bool erase_if_last_ref = false) override;
+  virtual bool IsReady(Handle* handle) override;
+  virtual void Wait(Handle* handle) override;
  virtual bool Ref(Handle* handle) override;
-  virtual bool Release(Handle* handle, bool force_erase = false) override;
+  virtual bool Release(Handle* handle, bool erase_if_last_ref = false) override;
  virtual void Erase(const Slice& key) override;
  virtual uint64_t NewId() override;
  virtual size_t GetCapacity() const override;
@@ -82,24 +106,21 @@ class ShardedCache : public Cache {
  virtual size_t GetUsage() const override;
  virtual size_t GetUsage(Handle* handle) const override;
  virtual size_t GetPinnedUsage() const override;
-  virtual void ApplyToAllCacheEntries(void (*callback)(void*, size_t),
-                                      bool thread_safe) override;
+  virtual void ApplyToAllEntries(
+      const std::function<void(const Slice& key, void* value, size_t charge,
+                               DeleterFn deleter)>& callback,
+      const ApplyToAllEntriesOptions& opts) override;
  virtual void EraseUnRefEntries() override;
  virtual std::string GetPrintableOptions() const override;

-  int GetNumShardBits() const { return num_shard_bits_; }
+  int GetNumShardBits() const;
+  uint32_t GetNumShards() const;
+
+ protected:
+  inline uint32_t Shard(uint32_t hash) { return hash & shard_mask_; }

 private:
-  static inline uint32_t HashSlice(const Slice& s) {
-    return static_cast<uint32_t>(GetSliceNPHash64(s));
-  }
-
-  uint32_t Shard(uint32_t hash) {
-    // Note, hash >> 32 yields hash in gcc, not the zero we expect!
-    return (num_shard_bits_ > 0) ? (hash >> (32 - num_shard_bits_)) : 0;
-  }
-
-  int num_shard_bits_;
+  const uint32_t shard_mask_;
  mutable port::Mutex capacity_mutex_;
  size_t capacity_;
  bool strict_capacity_limit_;
@@ -0,0 +1,26 @@
+# - Find liburing
+#
+# uring_INCLUDE_DIR - Where to find liburing.h
+# uring_LIBRARIES - List of libraries when using uring.
+# uring_FOUND - True if uring found.
+
+find_path(uring_INCLUDE_DIR
+  NAMES liburing.h)
+find_library(uring_LIBRARIES
+  NAMES liburing.a liburing)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(uring
+  DEFAULT_MSG uring_LIBRARIES uring_INCLUDE_DIR)
+
+mark_as_advanced(
+  uring_INCLUDE_DIR
+  uring_LIBRARIES)
+
+if(uring_FOUND AND NOT TARGET uring::uring)
+  add_library(uring::uring UNKNOWN IMPORTED)
+  set_target_properties(uring::uring PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES "${uring_INCLUDE_DIR}"
+    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+    IMPORTED_LOCATION "${uring_LIBRARIES}")
+endif()
@@ -12,7 +12,7 @@ fi
 ROOT=".."
 # Fetch right version of gcov
 if [ -d /mnt/gvfs/third-party -a -z "$CXX" ]; then
-  source $ROOT/build_tools/fbcode_config_platform007.sh
+  source $ROOT/build_tools/fbcode_config_platform009.sh
  GCOV=$GCC_BASE/bin/gcov
 else
  GCOV=$(which gcov)
@@ -24,7 +24,7 @@ mkdir -p $COVERAGE_DIR

 # Find all gcno files to generate the coverage report

-PYTHON=${1:-`which python`}
+PYTHON=${1:-`which python3`}
 echo -e "Using $PYTHON"
 GCNO_FILES=`find $ROOT -name "*.gcno"`
 $GCOV --preserve-paths --relative-only --no-output $GCNO_FILES 2>/dev/null |
@@ -0,0 +1,93 @@
+# This file is used by Meta-internal infrastructure as well as by Makefile
+
+# When included from Makefile, there are rules to build DB_STRESS_CMD. When
+# used directly with `make -f crashtest.mk ...` there will be no rules to
+# build DB_STRESS_CMD so it must exist prior.
+DB_STRESS_CMD?=./db_stress
+
+include python.mk
+
+CRASHTEST_MAKE=$(MAKE) -f crash_test.mk
+CRASHTEST_PY=$(PYTHON) -u tools/db_crashtest.py --stress_cmd=$(DB_STRESS_CMD)
+
+.PHONY: crash_test crash_test_with_atomic_flush crash_test_with_txn \
+	crash_test_with_best_efforts_recovery crash_test_with_ts \
+	blackbox_crash_test blackbox_crash_test_with_atomic_flush \
+	blackbox_crash_test_with_txn blackbox_crash_test_with_ts \
+	blackbox_crash_test_with_best_efforts_recovery \
+	whitebox_crash_test whitebox_crash_test_with_atomic_flush \
+	whitebox_crash_test_with_txn whitebox_crash_test_with_ts \
+	blackbox_crash_test_with_multiops_wc_txn \
+	blackbox_crash_test_with_multiops_wp_txn
+
+crash_test: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test
+	$(CRASHTEST_MAKE) blackbox_crash_test
+
+crash_test_with_atomic_flush: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_atomic_flush
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_atomic_flush
+
+crash_test_with_txn: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_txn
+
+crash_test_with_best_efforts_recovery: blackbox_crash_test_with_best_efforts_recovery
+
+crash_test_with_ts: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_ts
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_ts
+
+crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_multiops_wc_txn
+
+crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_multiops_wp_txn
+
+blackbox_crash_test: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --simple blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_atomic_flush: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --cf_consistency blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_best_efforts_recovery: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --test_best_efforts_recovery blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_ts: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --enable_ts blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
+	$(PYTHON) -u tools/db_crashtest.py --test_multiops_txn --write_policy write_committed blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
+	$(PYTHON) -u tools/db_crashtest.py --test_multiops_txn --write_policy write_prepared blackbox $(CRASH_TEST_EXT_ARGS)
+
+ifeq ($(CRASH_TEST_KILL_ODD),)
+  CRASH_TEST_KILL_ODD=888887
+endif
+
+whitebox_crash_test: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --simple whitebox --random_kill_odd \
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) whitebox  --random_kill_odd \
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_atomic_flush: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --cf_consistency whitebox  --random_kill_odd \
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --random_kill_odd \
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_ts: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --enable_ts whitebox --random_kill_odd \
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
@@ -31,16 +31,15 @@ Status ArenaWrappedDBIter::GetProperty(std::string prop_name,
 }

 void ArenaWrappedDBIter::Init(
-    Env* env, const ReadOptions& read_options,
-    const ImmutableCFOptions& cf_options,
+    Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
    const MutableCFOptions& mutable_cf_options, const Version* version,
    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iteration,
    uint64_t version_number, ReadCallback* read_callback, DBImpl* db_impl,
    ColumnFamilyData* cfd, bool expose_blob_index, bool allow_refresh) {
  auto mem = arena_.AllocateAligned(sizeof(DBIter));
  db_iter_ =
-      new (mem) DBIter(env, read_options, cf_options, mutable_cf_options,
-                       cf_options.user_comparator, /* iter */ nullptr, version,
+      new (mem) DBIter(env, read_options, ioptions, mutable_cf_options,
+                       ioptions.user_comparator, /* iter */ nullptr, version,
                       sequence, true, max_sequential_skip_in_iteration,
                       read_callback, db_impl, cfd, expose_blob_index);
  sv_number_ = version_number;
@@ -59,45 +58,69 @@ Status ArenaWrappedDBIter::Refresh() {
  uint64_t cur_sv_number = cfd_->GetSuperVersionNumber();
  TEST_SYNC_POINT("ArenaWrappedDBIter::Refresh:1");
  TEST_SYNC_POINT("ArenaWrappedDBIter::Refresh:2");
-  if (sv_number_ != cur_sv_number) {
-    Env* env = db_iter_->env();
-    db_iter_->~DBIter();
-    arena_.~Arena();
-    new (&arena_) Arena();
+  while (true) {
+    if (sv_number_ != cur_sv_number) {
+      Env* env = db_iter_->env();
+      db_iter_->~DBIter();
+      arena_.~Arena();
+      new (&arena_) Arena();

-    SuperVersion* sv = cfd_->GetReferencedSuperVersion(db_impl_);
-    SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
-    if (read_callback_) {
-      read_callback_->Refresh(latest_seq);
+      SuperVersion* sv = cfd_->GetReferencedSuperVersion(db_impl_);
+      SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
+      if (read_callback_) {
+        read_callback_->Refresh(latest_seq);
+      }
+      Init(env, read_options_, *(cfd_->ioptions()), sv->mutable_cf_options,
+           sv->current, latest_seq,
+           sv->mutable_cf_options.max_sequential_skip_in_iterations,
+           cur_sv_number, read_callback_, db_impl_, cfd_, expose_blob_index_,
+           allow_refresh_);
+
+      InternalIterator* internal_iter = db_impl_->NewInternalIterator(
+          read_options_, cfd_, sv, &arena_, db_iter_->GetRangeDelAggregator(),
+          latest_seq, /* allow_unprepared_value */ true);
+      SetIterUnderDBIter(internal_iter);
+      break;
+    } else {
+      SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
+      // Refresh range-tombstones in MemTable
+      if (!read_options_.ignore_range_deletions) {
+        SuperVersion* sv = cfd_->GetThreadLocalSuperVersion(db_impl_);
+        ReadRangeDelAggregator* range_del_agg =
+            db_iter_->GetRangeDelAggregator();
+        std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter;
+        range_del_iter.reset(
+            sv->mem->NewRangeTombstoneIterator(read_options_, latest_seq));
+        range_del_agg->AddTombstones(std::move(range_del_iter));
+        cfd_->ReturnThreadLocalSuperVersion(sv);
+      }
+      // Refresh latest sequence number
+      db_iter_->set_sequence(latest_seq);
+      db_iter_->set_valid(false);
+      // Check again if the latest super version number is changed
+      uint64_t latest_sv_number = cfd_->GetSuperVersionNumber();
+      if (latest_sv_number != cur_sv_number) {
+        // If the super version number is changed after refreshing,
+        // fallback to Re-Init the InternalIterator
+        cur_sv_number = latest_sv_number;
+        continue;
+      }
+      break;
    }
-    Init(env, read_options_, *(cfd_->ioptions()), sv->mutable_cf_options,
-         sv->current, latest_seq,
-         sv->mutable_cf_options.max_sequential_skip_in_iterations,
-         cur_sv_number, read_callback_, db_impl_, cfd_, expose_blob_index_,
-         allow_refresh_);
-
-    InternalIterator* internal_iter = db_impl_->NewInternalIterator(
-        read_options_, cfd_, sv, &arena_, db_iter_->GetRangeDelAggregator(),
-        latest_seq, /* allow_unprepared_value */ true);
-    SetIterUnderDBIter(internal_iter);
-  } else {
-    db_iter_->set_sequence(db_impl_->GetLatestSequenceNumber());
-    db_iter_->set_valid(false);
  }
  return Status::OK();
 }

 ArenaWrappedDBIter* NewArenaWrappedDbIterator(
-    Env* env, const ReadOptions& read_options,
-    const ImmutableCFOptions& cf_options,
+    Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
    const MutableCFOptions& mutable_cf_options, const Version* version,
    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,
    uint64_t version_number, ReadCallback* read_callback, DBImpl* db_impl,
    ColumnFamilyData* cfd, bool expose_blob_index, bool allow_refresh) {
  ArenaWrappedDBIter* iter = new ArenaWrappedDBIter();
-  iter->Init(env, read_options, cf_options, mutable_cf_options, version,
-             sequence, max_sequential_skip_in_iterations, version_number,
-             read_callback, db_impl, cfd, expose_blob_index, allow_refresh);
+  iter->Init(env, read_options, ioptions, mutable_cf_options, version, sequence,
+             max_sequential_skip_in_iterations, version_number, read_callback,
+             db_impl, cfd, expose_blob_index, allow_refresh);
  if (db_impl != nullptr && cfd != nullptr && allow_refresh) {
    iter->StoreRefreshInfo(db_impl, cfd, read_callback, expose_blob_index);
  }
@@ -12,7 +12,6 @@
 #include <string>
 #include "db/db_impl/db_impl.h"
 #include "db/db_iter.h"
-#include "db/dbformat.h"
 #include "db/range_del_aggregator.h"
 #include "memory/arena.h"
 #include "options/cf_options.h"
@@ -34,7 +33,13 @@ class Version;
 // the same as the inner DBIter.
 class ArenaWrappedDBIter : public Iterator {
 public:
-  virtual ~ArenaWrappedDBIter() { db_iter_->~DBIter(); }
+  ~ArenaWrappedDBIter() override {
+    if (db_iter_ != nullptr) {
+      db_iter_->~DBIter();
+    } else {
+      assert(false);
+    }
+  }

  // Get the arena to be used to allocate memory for DBIter to be wrapped,
  // as well as child iterators in it.
@@ -72,7 +77,7 @@ class ArenaWrappedDBIter : public Iterator {
  Status Refresh() override;

  void Init(Env* env, const ReadOptions& read_options,
-            const ImmutableCFOptions& cf_options,
+            const ImmutableOptions& ioptions,
            const MutableCFOptions& mutable_cf_options, const Version* version,
            const SequenceNumber& sequence,
            uint64_t max_sequential_skip_in_iterations, uint64_t version_number,
@@ -90,7 +95,7 @@ class ArenaWrappedDBIter : public Iterator {
  }

 private:
-  DBIter* db_iter_;
+  DBIter* db_iter_ = nullptr;
  Arena arena_;
  uint64_t sv_number_;
  ColumnFamilyData* cfd_ = nullptr;
@@ -105,8 +110,7 @@ class ArenaWrappedDBIter : public Iterator {
 // `db_impl` and `cfd` are used for reneweal. If left null, renewal will not
 // be supported.
 extern ArenaWrappedDBIter* NewArenaWrappedDbIterator(
-    Env* env, const ReadOptions& read_options,
-    const ImmutableCFOptions& cf_options,
+    Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
    const MutableCFOptions& mutable_cf_options, const Version* version,
    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,
    uint64_t version_number, ReadCallback* read_callback,
@@ -0,0 +1,146 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <cassert>
+
+#include "db/blob/blob_garbage_meter.h"
+#include "rocksdb/rocksdb_namespace.h"
+#include "rocksdb/status.h"
+#include "table/internal_iterator.h"
+#include "test_util/sync_point.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// An internal iterator that passes each key-value encountered to
+// BlobGarbageMeter as inflow in order to measure the total number and size of
+// blobs in the compaction input on a per-blob file basis.
+class BlobCountingIterator : public InternalIterator {
+ public:
+  BlobCountingIterator(InternalIterator* iter,
+                       BlobGarbageMeter* blob_garbage_meter)
+      : iter_(iter), blob_garbage_meter_(blob_garbage_meter) {
+    assert(iter_);
+    assert(blob_garbage_meter_);
+
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  bool Valid() const override { return iter_->Valid() && status_.ok(); }
+
+  void SeekToFirst() override {
+    iter_->SeekToFirst();
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  void SeekToLast() override {
+    iter_->SeekToLast();
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  void Seek(const Slice& target) override {
+    iter_->Seek(target);
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  void SeekForPrev(const Slice& target) override {
+    iter_->SeekForPrev(target);
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  void Next() override {
+    assert(Valid());
+
+    iter_->Next();
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  bool NextAndGetResult(IterateResult* result) override {
+    assert(Valid());
+
+    const bool res = iter_->NextAndGetResult(result);
+    UpdateAndCountBlobIfNeeded();
+    return res;
+  }
+
+  void Prev() override {
+    assert(Valid());
+
+    iter_->Prev();
+    UpdateAndCountBlobIfNeeded();
+  }
+
+  Slice key() const override {
+    assert(Valid());
+    return iter_->key();
+  }
+
+  Slice user_key() const override {
+    assert(Valid());
+    return iter_->user_key();
+  }
+
+  Slice value() const override {
+    assert(Valid());
+    return iter_->value();
+  }
+
+  Status status() const override { return status_; }
+
+  bool PrepareValue() override {
+    assert(Valid());
+    return iter_->PrepareValue();
+  }
+
+  bool MayBeOutOfLowerBound() override {
+    assert(Valid());
+    return iter_->MayBeOutOfLowerBound();
+  }
+
+  IterBoundCheck UpperBoundCheckResult() override {
+    assert(Valid());
+    return iter_->UpperBoundCheckResult();
+  }
+
+  void SetPinnedItersMgr(PinnedIteratorsManager* pinned_iters_mgr) override {
+    iter_->SetPinnedItersMgr(pinned_iters_mgr);
+  }
+
+  bool IsKeyPinned() const override {
+    assert(Valid());
+    return iter_->IsKeyPinned();
+  }
+
+  bool IsValuePinned() const override {
+    assert(Valid());
+    return iter_->IsValuePinned();
+  }
+
+  Status GetProperty(std::string prop_name, std::string* prop) override {
+    return iter_->GetProperty(prop_name, prop);
+  }
+
+ private:
+  void UpdateAndCountBlobIfNeeded() {
+    assert(!iter_->Valid() || iter_->status().ok());
+
+    if (!iter_->Valid()) {
+      status_ = iter_->status();
+      return;
+    }
+
+    TEST_SYNC_POINT(
+        "BlobCountingIterator::UpdateAndCountBlobIfNeeded:ProcessInFlow");
+
+    status_ = blob_garbage_meter_->ProcessInFlow(key(), value());
+  }
+
+  InternalIterator* iter_;
+  BlobGarbageMeter* blob_garbage_meter_;
+  Status status_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,326 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/blob_counting_iterator.h"
+
+#include <string>
+#include <vector>
+
+#include "db/blob/blob_garbage_meter.h"
+#include "db/blob/blob_index.h"
+#include "db/blob/blob_log_format.h"
+#include "db/dbformat.h"
+#include "test_util/testharness.h"
+#include "test_util/testutil.h"
+#include "util/vector_iterator.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+void CheckInFlow(const BlobGarbageMeter& blob_garbage_meter,
+                 uint64_t blob_file_number, uint64_t count, uint64_t bytes) {
+  const auto& flows = blob_garbage_meter.flows();
+
+  const auto it = flows.find(blob_file_number);
+  if (it == flows.end()) {
+    ASSERT_EQ(count, 0);
+    ASSERT_EQ(bytes, 0);
+    return;
+  }
+
+  const auto& in = it->second.GetInFlow();
+
+  ASSERT_EQ(in.GetCount(), count);
+  ASSERT_EQ(in.GetBytes(), bytes);
+}
+
+TEST(BlobCountingIteratorTest, CountBlobs) {
+  // Note: the input consists of three key-values: two are blob references to
+  // different blob files, while the third one is a plain value.
+  constexpr char user_key0[] = "key0";
+  constexpr char user_key1[] = "key1";
+  constexpr char user_key2[] = "key2";
+
+  const std::vector<std::string> keys{
+      test::KeyStr(user_key0, 1, kTypeBlobIndex),
+      test::KeyStr(user_key1, 2, kTypeBlobIndex),
+      test::KeyStr(user_key2, 3, kTypeValue)};
+
+  constexpr uint64_t first_blob_file_number = 4;
+  constexpr uint64_t first_offset = 1000;
+  constexpr uint64_t first_size = 2000;
+
+  std::string first_blob_index;
+  BlobIndex::EncodeBlob(&first_blob_index, first_blob_file_number, first_offset,
+                        first_size, kNoCompression);
+
+  constexpr uint64_t second_blob_file_number = 6;
+  constexpr uint64_t second_offset = 2000;
+  constexpr uint64_t second_size = 4000;
+
+  std::string second_blob_index;
+  BlobIndex::EncodeBlob(&second_blob_index, second_blob_file_number,
+                        second_offset, second_size, kNoCompression);
+
+  const std::vector<std::string> values{first_blob_index, second_blob_index,
+                                        "raw_value"};
+
+  assert(keys.size() == values.size());
+
+  VectorIterator input(keys, values);
+  BlobGarbageMeter blob_garbage_meter;
+
+  BlobCountingIterator blob_counter(&input, &blob_garbage_meter);
+
+  constexpr uint64_t first_expected_bytes =
+      first_size +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(user_key0) - 1);
+  constexpr uint64_t second_expected_bytes =
+      second_size +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(user_key1) - 1);
+
+  // Call SeekToFirst and iterate forward
+  blob_counter.SeekToFirst();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[0]);
+  ASSERT_EQ(blob_counter.user_key(), user_key0);
+  ASSERT_EQ(blob_counter.value(), values[0]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 1,
+              first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 0, 0);
+
+  blob_counter.Next();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[1]);
+  ASSERT_EQ(blob_counter.user_key(), user_key1);
+  ASSERT_EQ(blob_counter.value(), values[1]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 1,
+              first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 1,
+              second_expected_bytes);
+
+  blob_counter.Next();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[2]);
+  ASSERT_EQ(blob_counter.user_key(), user_key2);
+  ASSERT_EQ(blob_counter.value(), values[2]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 1,
+              first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 1,
+              second_expected_bytes);
+
+  blob_counter.Next();
+  ASSERT_FALSE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 1,
+              first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 1,
+              second_expected_bytes);
+
+  // Do it again using NextAndGetResult
+  blob_counter.SeekToFirst();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[0]);
+  ASSERT_EQ(blob_counter.user_key(), user_key0);
+  ASSERT_EQ(blob_counter.value(), values[0]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 2,
+              2 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 1,
+              second_expected_bytes);
+
+  {
+    IterateResult result;
+    ASSERT_TRUE(blob_counter.NextAndGetResult(&result));
+    ASSERT_EQ(result.key, keys[1]);
+    ASSERT_EQ(blob_counter.user_key(), user_key1);
+    ASSERT_TRUE(blob_counter.Valid());
+    ASSERT_OK(blob_counter.status());
+    ASSERT_EQ(blob_counter.key(), keys[1]);
+    ASSERT_EQ(blob_counter.value(), values[1]);
+    CheckInFlow(blob_garbage_meter, first_blob_file_number, 2,
+                2 * first_expected_bytes);
+    CheckInFlow(blob_garbage_meter, second_blob_file_number, 2,
+                2 * second_expected_bytes);
+  }
+
+  {
+    IterateResult result;
+    ASSERT_TRUE(blob_counter.NextAndGetResult(&result));
+    ASSERT_EQ(result.key, keys[2]);
+    ASSERT_EQ(blob_counter.user_key(), user_key2);
+    ASSERT_TRUE(blob_counter.Valid());
+    ASSERT_OK(blob_counter.status());
+    ASSERT_EQ(blob_counter.key(), keys[2]);
+    ASSERT_EQ(blob_counter.value(), values[2]);
+    CheckInFlow(blob_garbage_meter, first_blob_file_number, 2,
+                2 * first_expected_bytes);
+    CheckInFlow(blob_garbage_meter, second_blob_file_number, 2,
+                2 * second_expected_bytes);
+  }
+
+  {
+    IterateResult result;
+    ASSERT_FALSE(blob_counter.NextAndGetResult(&result));
+    ASSERT_FALSE(blob_counter.Valid());
+    ASSERT_OK(blob_counter.status());
+    CheckInFlow(blob_garbage_meter, first_blob_file_number, 2,
+                2 * first_expected_bytes);
+    CheckInFlow(blob_garbage_meter, second_blob_file_number, 2,
+                2 * second_expected_bytes);
+  }
+
+  // Call SeekToLast and iterate backward
+  blob_counter.SeekToLast();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[2]);
+  ASSERT_EQ(blob_counter.user_key(), user_key2);
+  ASSERT_EQ(blob_counter.value(), values[2]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 2,
+              2 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 2,
+              2 * second_expected_bytes);
+
+  blob_counter.Prev();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[1]);
+  ASSERT_EQ(blob_counter.user_key(), user_key1);
+  ASSERT_EQ(blob_counter.value(), values[1]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 2,
+              2 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 3,
+              3 * second_expected_bytes);
+
+  blob_counter.Prev();
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[0]);
+  ASSERT_EQ(blob_counter.user_key(), user_key0);
+  ASSERT_EQ(blob_counter.value(), values[0]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 3,
+              3 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 3,
+              3 * second_expected_bytes);
+
+  blob_counter.Prev();
+  ASSERT_FALSE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 3,
+              3 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 3,
+              3 * second_expected_bytes);
+
+  // Call Seek for all keys (plus one that's greater than all of them)
+  blob_counter.Seek(keys[0]);
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[0]);
+  ASSERT_EQ(blob_counter.user_key(), user_key0);
+  ASSERT_EQ(blob_counter.value(), values[0]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 4,
+              4 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 3,
+              3 * second_expected_bytes);
+
+  blob_counter.Seek(keys[1]);
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[1]);
+  ASSERT_EQ(blob_counter.user_key(), user_key1);
+  ASSERT_EQ(blob_counter.value(), values[1]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 4,
+              4 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 4,
+              4 * second_expected_bytes);
+
+  blob_counter.Seek(keys[2]);
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[2]);
+  ASSERT_EQ(blob_counter.user_key(), user_key2);
+  ASSERT_EQ(blob_counter.value(), values[2]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 4,
+              4 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 4,
+              4 * second_expected_bytes);
+
+  blob_counter.Seek("zzz");
+  ASSERT_FALSE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 4,
+              4 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 4,
+              4 * second_expected_bytes);
+
+  // Call SeekForPrev for all keys (plus one that's less than all of them)
+  blob_counter.SeekForPrev("aaa");
+  ASSERT_FALSE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 4,
+              4 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 4,
+              4 * second_expected_bytes);
+
+  blob_counter.SeekForPrev(keys[0]);
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[0]);
+  ASSERT_EQ(blob_counter.user_key(), user_key0);
+  ASSERT_EQ(blob_counter.value(), values[0]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 5,
+              5 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 4,
+              4 * second_expected_bytes);
+
+  blob_counter.SeekForPrev(keys[1]);
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[1]);
+  ASSERT_EQ(blob_counter.user_key(), user_key1);
+  ASSERT_EQ(blob_counter.value(), values[1]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 5,
+              5 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 5,
+              5 * second_expected_bytes);
+
+  blob_counter.SeekForPrev(keys[2]);
+  ASSERT_TRUE(blob_counter.Valid());
+  ASSERT_OK(blob_counter.status());
+  ASSERT_EQ(blob_counter.key(), keys[2]);
+  ASSERT_EQ(blob_counter.user_key(), user_key2);
+  ASSERT_EQ(blob_counter.value(), values[2]);
+  CheckInFlow(blob_garbage_meter, first_blob_file_number, 5,
+              5 * first_expected_bytes);
+  CheckInFlow(blob_garbage_meter, second_blob_file_number, 5,
+              5 * second_expected_bytes);
+}
+
+TEST(BlobCountingIteratorTest, CorruptBlobIndex) {
+  const std::vector<std::string> keys{
+      test::KeyStr("user_key", 1, kTypeBlobIndex)};
+  const std::vector<std::string> values{"i_am_not_a_blob_index"};
+
+  assert(keys.size() == values.size());
+
+  VectorIterator input(keys, values);
+  BlobGarbageMeter blob_garbage_meter;
+
+  BlobCountingIterator blob_counter(&input, &blob_garbage_meter);
+
+  blob_counter.SeekToFirst();
+  ASSERT_FALSE(blob_counter.Valid());
+  ASSERT_NOK(blob_counter.status());
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -0,0 +1,34 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/blob_fetcher.h"
+
+#include "db/version_set.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+Status BlobFetcher::FetchBlob(const Slice& user_key,
+                              const Slice& blob_index_slice,
+                              FilePrefetchBuffer* prefetch_buffer,
+                              PinnableSlice* blob_value,
+                              uint64_t* bytes_read) const {
+  assert(version_);
+
+  return version_->GetBlob(read_options_, user_key, blob_index_slice,
+                           prefetch_buffer, blob_value, bytes_read);
+}
+
+Status BlobFetcher::FetchBlob(const Slice& user_key,
+                              const BlobIndex& blob_index,
+                              FilePrefetchBuffer* prefetch_buffer,
+                              PinnableSlice* blob_value,
+                              uint64_t* bytes_read) const {
+  assert(version_);
+
+  return version_->GetBlob(read_options_, user_key, blob_index, prefetch_buffer,
+                           blob_value, bytes_read);
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,37 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include "rocksdb/options.h"
+#include "rocksdb/status.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Version;
+class Slice;
+class FilePrefetchBuffer;
+class PinnableSlice;
+class BlobIndex;
+
+// A thin wrapper around the blob retrieval functionality of Version.
+class BlobFetcher {
+ public:
+  BlobFetcher(const Version* version, const ReadOptions& read_options)
+      : version_(version), read_options_(read_options) {}
+
+  Status FetchBlob(const Slice& user_key, const Slice& blob_index_slice,
+                   FilePrefetchBuffer* prefetch_buffer,
+                   PinnableSlice* blob_value, uint64_t* bytes_read) const;
+
+  Status FetchBlob(const Slice& user_key, const BlobIndex& blob_index,
+                   FilePrefetchBuffer* prefetch_buffer,
+                   PinnableSlice* blob_value, uint64_t* bytes_read) const;
+
+ private:
+  const Version* version_;
+  ReadOptions read_options_;
+};
+}  // namespace ROCKSDB_NAMESPACE
@@ -135,7 +135,8 @@ std::ostream& operator<<(std::ostream& os,
     << " total_blob_count: " << blob_file_addition.GetTotalBlobCount()
     << " total_blob_bytes: " << blob_file_addition.GetTotalBlobBytes()
     << " checksum_method: " << blob_file_addition.GetChecksumMethod()
-     << " checksum_value: " << blob_file_addition.GetChecksumValue();
+     << " checksum_value: "
+     << Slice(blob_file_addition.GetChecksumValue()).ToString(/* hex */ true);

  return os;
 }
@@ -146,7 +147,8 @@ JSONWriter& operator<<(JSONWriter& jw,
     << "TotalBlobCount" << blob_file_addition.GetTotalBlobCount()
     << "TotalBlobBytes" << blob_file_addition.GetTotalBlobBytes()
     << "ChecksumMethod" << blob_file_addition.GetChecksumMethod()
-     << "ChecksumValue" << blob_file_addition.GetChecksumValue();
+     << "ChecksumValue"
+     << Slice(blob_file_addition.GetChecksumValue()).ToString(/* hex */ true);

  return jw;
 }
@@ -46,7 +46,9 @@ TEST_F(BlobFileAdditionTest, NonEmpty) {
  constexpr uint64_t total_blob_count = 2;
  constexpr uint64_t total_blob_bytes = 123456;
  const std::string checksum_method("SHA1");
-  const std::string checksum_value("bdb7f34a59dfa1592ce7f52e99f98c570c525cbd");
+  const std::string checksum_value(
+      "\xbd\xb7\xf3\x4a\x59\xdf\xa1\x59\x2c\xe7\xf5\x2e\x99\xf9\x8c\x57\x0c\x52"
+      "\x5c\xbd");

  BlobFileAddition blob_file_addition(blob_file_number, total_blob_count,
                                      total_blob_bytes, checksum_method,
@@ -113,7 +115,9 @@ TEST_F(BlobFileAdditionTest, DecodeErrors) {
    ASSERT_TRUE(std::strstr(s.getState(), "checksum value"));
  }

-  constexpr char checksum_value[] = "bdb7f34a59dfa1592ce7f52e99f98c570c525cbd";
+  constexpr char checksum_value[] =
+      "\xbd\xb7\xf3\x4a\x59\xdf\xa1\x59\x2c\xe7\xf5\x2e\x99\xf9\x8c\x57\x0c\x52"
+      "\x5c\xbd";
  PutLengthPrefixedSlice(&str, checksum_value);
  slice = str;

@@ -150,7 +154,7 @@ TEST_F(BlobFileAdditionTest, ForwardCompatibleCustomField) {
  constexpr uint64_t total_blob_count = 9999;
  constexpr uint64_t total_blob_bytes = 100000000;
  const std::string checksum_method("CRC32");
-  const std::string checksum_value("3d87ff57");
+  const std::string checksum_value("\x3d\x87\xff\x57");

  BlobFileAddition blob_file_addition(blob_file_number, total_blob_count,
                                      total_blob_bytes, checksum_method,
@@ -178,7 +182,7 @@ TEST_F(BlobFileAdditionTest, ForwardIncompatibleCustomField) {
  constexpr uint64_t total_blob_count = 100;
  constexpr uint64_t total_blob_bytes = 2000000;
  const std::string checksum_method("CRC32B");
-  const std::string checksum_value("6dbdf23a");
+  const std::string checksum_value("\x6d\xbd\xf2\x3a");

  BlobFileAddition blob_file_addition(blob_file_number, total_blob_count,
                                      total_blob_bytes, checksum_method,
@@ -12,6 +12,7 @@
 #include "db/blob/blob_index.h"
 #include "db/blob/blob_log_format.h"
 #include "db/blob/blob_log_writer.h"
+#include "db/event_helpers.h"
 #include "db/version_set.h"
 #include "file/filename.h"
 #include "file/read_write_util.h"
@@ -29,35 +30,37 @@ namespace ROCKSDB_NAMESPACE {

 BlobFileBuilder::BlobFileBuilder(
    VersionSet* versions, FileSystem* fs,
-    const ImmutableCFOptions* immutable_cf_options,
+    const ImmutableOptions* immutable_options,
    const MutableCFOptions* mutable_cf_options, const FileOptions* file_options,
    int job_id, uint32_t column_family_id,
    const std::string& column_family_name, Env::IOPriority io_priority,
    Env::WriteLifeTimeHint write_hint,
    const std::shared_ptr<IOTracer>& io_tracer,
    BlobFileCompletionCallback* blob_callback,
+    BlobFileCreationReason creation_reason,
    std::vector<std::string>* blob_file_paths,
    std::vector<BlobFileAddition>* blob_file_additions)
    : BlobFileBuilder([versions]() { return versions->NewFileNumber(); }, fs,
-                      immutable_cf_options, mutable_cf_options, file_options,
+                      immutable_options, mutable_cf_options, file_options,
                      job_id, column_family_id, column_family_name, io_priority,
-                      write_hint, io_tracer, blob_callback, blob_file_paths,
-                      blob_file_additions) {}
+                      write_hint, io_tracer, blob_callback, creation_reason,
+                      blob_file_paths, blob_file_additions) {}

 BlobFileBuilder::BlobFileBuilder(
    std::function<uint64_t()> file_number_generator, FileSystem* fs,
-    const ImmutableCFOptions* immutable_cf_options,
+    const ImmutableOptions* immutable_options,
    const MutableCFOptions* mutable_cf_options, const FileOptions* file_options,
    int job_id, uint32_t column_family_id,
    const std::string& column_family_name, Env::IOPriority io_priority,
    Env::WriteLifeTimeHint write_hint,
    const std::shared_ptr<IOTracer>& io_tracer,
    BlobFileCompletionCallback* blob_callback,
+    BlobFileCreationReason creation_reason,
    std::vector<std::string>* blob_file_paths,
    std::vector<BlobFileAddition>* blob_file_additions)
    : file_number_generator_(std::move(file_number_generator)),
      fs_(fs),
-      immutable_cf_options_(immutable_cf_options),
+      immutable_options_(immutable_options),
      min_blob_size_(mutable_cf_options->min_blob_size),
      blob_file_size_(mutable_cf_options->blob_file_size),
      blob_compression_type_(mutable_cf_options->blob_compression_type),
@@ -69,13 +72,14 @@ BlobFileBuilder::BlobFileBuilder(
      write_hint_(write_hint),
      io_tracer_(io_tracer),
      blob_callback_(blob_callback),
+      creation_reason_(creation_reason),
      blob_file_paths_(blob_file_paths),
      blob_file_additions_(blob_file_additions),
      blob_count_(0),
      blob_bytes_(0) {
  assert(file_number_generator_);
  assert(fs_);
-  assert(immutable_cf_options_);
+  assert(immutable_options_);
  assert(file_options_);
  assert(blob_file_paths_);
  assert(blob_file_paths_->empty());
@@ -156,10 +160,15 @@ Status BlobFileBuilder::OpenBlobFileIfNeeded() {
  assert(file_number_generator_);
  const uint64_t blob_file_number = file_number_generator_();

-  assert(immutable_cf_options_);
-  assert(!immutable_cf_options_->cf_paths.empty());
-  std::string blob_file_path = BlobFileName(
-      immutable_cf_options_->cf_paths.front().path, blob_file_number);
+  assert(immutable_options_);
+  assert(!immutable_options_->cf_paths.empty());
+  std::string blob_file_path =
+      BlobFileName(immutable_options_->cf_paths.front().path, blob_file_number);
+
+  if (blob_callback_) {
+    blob_callback_->OnBlobFileCreationStarted(
+        blob_file_path, column_family_name_, job_id_, creation_reason_);
+  }

  std::unique_ptr<FSWritableFile> file;

@@ -184,20 +193,20 @@ Status BlobFileBuilder::OpenBlobFileIfNeeded() {
  assert(file);
  file->SetIOPriority(io_priority_);
  file->SetWriteLifeTimeHint(write_hint_);
-  FileTypeSet tmp_set = immutable_cf_options_->checksum_handoff_file_types;
-  Statistics* const statistics = immutable_cf_options_->statistics;
+  FileTypeSet tmp_set = immutable_options_->checksum_handoff_file_types;
+  Statistics* const statistics = immutable_options_->stats;
  std::unique_ptr<WritableFileWriter> file_writer(new WritableFileWriter(
      std::move(file), blob_file_paths_->back(), *file_options_,
-      immutable_cf_options_->clock, io_tracer_, statistics,
-      immutable_cf_options_->listeners,
-      immutable_cf_options_->file_checksum_gen_factory.get(),
-      tmp_set.Contains(FileType::kBlobFile)));
+      immutable_options_->clock, io_tracer_, statistics,
+      immutable_options_->listeners,
+      immutable_options_->file_checksum_gen_factory.get(),
+      tmp_set.Contains(FileType::kBlobFile), false));

  constexpr bool do_flush = false;

  std::unique_ptr<BlobLogWriter> blob_log_writer(new BlobLogWriter(
-      std::move(file_writer), immutable_cf_options_->clock, statistics,
-      blob_file_number, immutable_cf_options_->use_fsync, do_flush));
+      std::move(file_writer), immutable_options_->clock, statistics,
+      blob_file_number, immutable_options_->use_fsync, do_flush));

  constexpr bool has_ttl = false;
  constexpr ExpirationRange expiration_range;
@@ -228,6 +237,7 @@ Status BlobFileBuilder::CompressBlobIfNeeded(
  assert(blob);
  assert(compressed_blob);
  assert(compressed_blob->empty());
+  assert(immutable_options_);

  if (blob_compression_type_ == kNoCompression) {
    return Status::OK();
@@ -242,7 +252,16 @@ Status BlobFileBuilder::CompressBlobIfNeeded(

  constexpr uint32_t compression_format_version = 2;

-  if (!CompressData(*blob, info, compression_format_version, compressed_blob)) {
+  bool success = false;
+
+  {
+    StopWatch stop_watch(immutable_options_->clock, immutable_options_->stats,
+                         BLOB_DB_COMPRESSION_MICROS);
+    success =
+        CompressData(*blob, info, compression_format_version, compressed_blob);
+  }
+
+  if (!success) {
    return Status::Corruption("Error compressing blob");
  }

@@ -295,20 +314,24 @@ Status BlobFileBuilder::CloseBlobFile() {

  const uint64_t blob_file_number = writer_->get_log_number();

+  if (blob_callback_) {
+    s = blob_callback_->OnBlobFileCompleted(
+        blob_file_paths_->back(), column_family_name_, job_id_,
+        blob_file_number, creation_reason_, s, checksum_value, checksum_method,
+        blob_count_, blob_bytes_);
+  }
+
  assert(blob_file_additions_);
  blob_file_additions_->emplace_back(blob_file_number, blob_count_, blob_bytes_,
                                     std::move(checksum_method),
                                     std::move(checksum_value));

-  assert(immutable_cf_options_);
-  ROCKS_LOG_INFO(immutable_cf_options_->info_log,
+  assert(immutable_options_);
+  ROCKS_LOG_INFO(immutable_options_->logger,
                 "[%s] [JOB %d] Generated blob file #%" PRIu64 ": %" PRIu64
                 " total blobs, %" PRIu64 " total bytes",
                 column_family_name_.c_str(), job_id_, blob_file_number,
                 blob_count_, blob_bytes_);
-  if (blob_callback_) {
-    s = blob_callback_->OnBlobFileCompleted(blob_file_paths_->back());
-  }

  writer_.reset();
  blob_count_ = 0;
@@ -330,15 +353,18 @@ Status BlobFileBuilder::CloseBlobFileIfNeeded() {
  return CloseBlobFile();
 }

-void BlobFileBuilder::Abandon() {
+void BlobFileBuilder::Abandon(const Status& s) {
  if (!IsBlobFileOpen()) {
    return;
  }
-
  if (blob_callback_) {
    // BlobFileBuilder::Abandon() is called because of error while writing to
    // Blob files. So we can ignore the below error.
-    blob_callback_->OnBlobFileCompleted(blob_file_paths_->back())
+    blob_callback_
+        ->OnBlobFileCompleted(blob_file_paths_->back(), column_family_name_,
+                              job_id_, writer_->get_log_number(),
+                              creation_reason_, s, "", "", blob_count_,
+                              blob_bytes_)
        .PermitUncheckedError();
  }

@@ -13,13 +13,14 @@
 #include "rocksdb/compression_type.h"
 #include "rocksdb/env.h"
 #include "rocksdb/rocksdb_namespace.h"
+#include "rocksdb/types.h"

 namespace ROCKSDB_NAMESPACE {

 class VersionSet;
 class FileSystem;
 class SystemClock;
-struct ImmutableCFOptions;
+struct ImmutableOptions;
 struct MutableCFOptions;
 struct FileOptions;
 class BlobFileAddition;
@@ -32,7 +33,7 @@ class BlobFileCompletionCallback;
 class BlobFileBuilder {
 public:
  BlobFileBuilder(VersionSet* versions, FileSystem* fs,
-                  const ImmutableCFOptions* immutable_cf_options,
+                  const ImmutableOptions* immutable_options,
                  const MutableCFOptions* mutable_cf_options,
                  const FileOptions* file_options, int job_id,
                  uint32_t column_family_id,
@@ -41,12 +42,12 @@ class BlobFileBuilder {
                  Env::WriteLifeTimeHint write_hint,
                  const std::shared_ptr<IOTracer>& io_tracer,
                  BlobFileCompletionCallback* blob_callback,
+                  BlobFileCreationReason creation_reason,
                  std::vector<std::string>* blob_file_paths,
                  std::vector<BlobFileAddition>* blob_file_additions);

  BlobFileBuilder(std::function<uint64_t()> file_number_generator,
-                  FileSystem* fs,
-                  const ImmutableCFOptions* immutable_cf_options,
+                  FileSystem* fs, const ImmutableOptions* immutable_options,
                  const MutableCFOptions* mutable_cf_options,
                  const FileOptions* file_options, int job_id,
                  uint32_t column_family_id,
@@ -55,6 +56,7 @@ class BlobFileBuilder {
                  Env::WriteLifeTimeHint write_hint,
                  const std::shared_ptr<IOTracer>& io_tracer,
                  BlobFileCompletionCallback* blob_callback,
+                  BlobFileCreationReason creation_reason,
                  std::vector<std::string>* blob_file_paths,
                  std::vector<BlobFileAddition>* blob_file_additions);

@@ -65,7 +67,7 @@ class BlobFileBuilder {

  Status Add(const Slice& key, const Slice& value, std::string* blob_index);
  Status Finish();
-  void Abandon();
+  void Abandon(const Status& s);

 private:
  bool IsBlobFileOpen() const;
@@ -78,7 +80,7 @@ class BlobFileBuilder {

  std::function<uint64_t()> file_number_generator_;
  FileSystem* fs_;
-  const ImmutableCFOptions* immutable_cf_options_;
+  const ImmutableOptions* immutable_options_;
  uint64_t min_blob_size_;
  uint64_t blob_file_size_;
  CompressionType blob_compression_type_;
@@ -90,6 +92,7 @@ class BlobFileBuilder {
  Env::WriteLifeTimeHint write_hint_;
  std::shared_ptr<IOTracer> io_tracer_;
  BlobFileCompletionCallback* blob_callback_;
+  BlobFileCreationReason creation_reason_;
  std::vector<std::string>* blob_file_paths_;
  std::vector<BlobFileAddition>* blob_file_additions_;
  std::unique_ptr<BlobLogWriter> writer_;
@@ -39,9 +39,10 @@ class TestFileNumberGenerator {

 class BlobFileBuilderTest : public testing::Test {
 protected:
-  BlobFileBuilderTest() : mock_env_(Env::Default()) {
-    fs_ = mock_env_.GetFileSystem().get();
-    clock_ = mock_env_.GetSystemClock().get();
+  BlobFileBuilderTest() {
+    mock_env_.reset(MockEnv::Create(Env::Default()));
+    fs_ = mock_env_->GetFileSystem().get();
+    clock_ = mock_env_->GetSystemClock().get();
  }

  void VerifyBlobFile(uint64_t blob_file_number,
@@ -108,7 +109,7 @@ class BlobFileBuilderTest : public testing::Test {
    ASSERT_EQ(footer.expiration_range, ExpirationRange());
  }

-  MockEnv mock_env_;
+  std::unique_ptr<Env> mock_env_;
  FileSystem* fs_;
  SystemClock* clock_;
  FileOptions file_options_;
@@ -123,13 +124,13 @@ TEST_F(BlobFileBuilderTest, BuildAndCheckOneFile) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileBuilderTest_BuildAndCheckOneFile"),
      0);
  options.enable_blob_files = true;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -141,12 +142,11 @@ TEST_F(BlobFileBuilderTest, BuildAndCheckOneFile) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  std::vector<std::pair<std::string, std::string>> expected_key_value_pairs(
      number_of_blobs);
@@ -178,9 +178,9 @@ TEST_F(BlobFileBuilderTest, BuildAndCheckOneFile) {

  const std::string& blob_file_path = blob_file_paths[0];

-  ASSERT_EQ(blob_file_path,
-            BlobFileName(immutable_cf_options.cf_paths.front().path,
-                         blob_file_number));
+  ASSERT_EQ(
+      blob_file_path,
+      BlobFileName(immutable_options.cf_paths.front().path, blob_file_number));

  ASSERT_EQ(blob_file_additions.size(), 1);

@@ -207,14 +207,14 @@ TEST_F(BlobFileBuilderTest, BuildAndCheckMultipleFiles) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileBuilderTest_BuildAndCheckMultipleFiles"),
      0);
  options.enable_blob_files = true;
  options.blob_file_size = value_size;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -226,12 +226,11 @@ TEST_F(BlobFileBuilderTest, BuildAndCheckMultipleFiles) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  std::vector<std::pair<std::string, std::string>> expected_key_value_pairs(
      number_of_blobs);
@@ -264,7 +263,7 @@ TEST_F(BlobFileBuilderTest, BuildAndCheckMultipleFiles) {
    const uint64_t blob_file_number = i + 2;

    ASSERT_EQ(blob_file_paths[i],
-              BlobFileName(immutable_cf_options.cf_paths.front().path,
+              BlobFileName(immutable_options.cf_paths.front().path,
                           blob_file_number));

    const auto& blob_file_addition = blob_file_additions[i];
@@ -295,13 +294,14 @@ TEST_F(BlobFileBuilderTest, InlinedValues) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileBuilderTest_InlinedValues"),
+      test::PerThreadDBPath(mock_env_.get(),
+                            "BlobFileBuilderTest_InlinedValues"),
      0);
  options.enable_blob_files = true;
  options.min_blob_size = 1024;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -313,12 +313,11 @@ TEST_F(BlobFileBuilderTest, InlinedValues) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  for (size_t i = 0; i < number_of_blobs; ++i) {
    const std::string key = std::to_string(i);
@@ -350,12 +349,13 @@ TEST_F(BlobFileBuilderTest, Compression) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileBuilderTest_Compression"), 0);
+      test::PerThreadDBPath(mock_env_.get(), "BlobFileBuilderTest_Compression"),
+      0);
  options.enable_blob_files = true;
  options.blob_compression_type = kSnappyCompression;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -367,12 +367,11 @@ TEST_F(BlobFileBuilderTest, Compression) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  const std::string key("1");
  const std::string uncompressed_value(value_size, 'x');
@@ -391,9 +390,9 @@ TEST_F(BlobFileBuilderTest, Compression) {

  const std::string& blob_file_path = blob_file_paths[0];

-  ASSERT_EQ(blob_file_path,
-            BlobFileName(immutable_cf_options.cf_paths.front().path,
-                         blob_file_number));
+  ASSERT_EQ(
+      blob_file_path,
+      BlobFileName(immutable_options.cf_paths.front().path, blob_file_number));

  ASSERT_EQ(blob_file_additions.size(), 1);

@@ -433,12 +432,13 @@ TEST_F(BlobFileBuilderTest, CompressionError) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileBuilderTest_CompressionError"),
+      test::PerThreadDBPath(mock_env_.get(),
+                            "BlobFileBuilderTest_CompressionError"),
      0);
  options.enable_blob_files = true;
  options.blob_compression_type = kSnappyCompression;
-  options.env = &mock_env_;
-  ImmutableCFOptions immutable_cf_options(options);
+  options.env = mock_env_.get();
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -450,12 +450,11 @@ TEST_F(BlobFileBuilderTest, CompressionError) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  SyncPoint::GetInstance()->SetCallBack("CompressData:TamperWithReturnValue",
                                        [](void* arg) {
@@ -477,9 +476,9 @@ TEST_F(BlobFileBuilderTest, CompressionError) {
  constexpr uint64_t blob_file_number = 2;

  ASSERT_EQ(blob_file_paths.size(), 1);
-  ASSERT_EQ(blob_file_paths[0],
-            BlobFileName(immutable_cf_options.cf_paths.front().path,
-                         blob_file_number));
+  ASSERT_EQ(
+      blob_file_paths[0],
+      BlobFileName(immutable_options.cf_paths.front().path, blob_file_number));

  ASSERT_TRUE(blob_file_additions.empty());
 }
@@ -511,13 +510,14 @@ TEST_F(BlobFileBuilderTest, Checksum) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileBuilderTest_Checksum"), 0);
+      test::PerThreadDBPath(mock_env_.get(), "BlobFileBuilderTest_Checksum"),
+      0);
  options.enable_blob_files = true;
  options.file_checksum_gen_factory =
      std::make_shared<DummyFileChecksumGenFactory>();
-  options.env = &mock_env_;
+  options.env = mock_env_.get();

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -529,12 +529,11 @@ TEST_F(BlobFileBuilderTest, Checksum) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  const std::string key("1");
  const std::string value("deadbeef");
@@ -553,9 +552,9 @@ TEST_F(BlobFileBuilderTest, Checksum) {

  const std::string& blob_file_path = blob_file_paths[0];

-  ASSERT_EQ(blob_file_path,
-            BlobFileName(immutable_cf_options.cf_paths.front().path,
-                         blob_file_number));
+  ASSERT_EQ(
+      blob_file_path,
+      BlobFileName(immutable_options.cf_paths.front().path, blob_file_number));

  ASSERT_EQ(blob_file_additions.size(), 1);

@@ -581,12 +580,12 @@ class BlobFileBuilderIOErrorTest
    : public testing::Test,
      public testing::WithParamInterface<std::string> {
 protected:
-  BlobFileBuilderIOErrorTest()
-      : mock_env_(Env::Default()),
-        fs_(mock_env_.GetFileSystem().get()),
-        sync_point_(GetParam()) {}
+  BlobFileBuilderIOErrorTest() : sync_point_(GetParam()) {
+    mock_env_.reset(MockEnv::Create(Env::Default()));
+    fs_ = mock_env_->GetFileSystem().get();
+  }

-  MockEnv mock_env_;
+  std::unique_ptr<Env> mock_env_;
  FileSystem* fs_;
  FileOptions file_options_;
  std::string sync_point_;
@@ -608,13 +607,14 @@ TEST_P(BlobFileBuilderIOErrorTest, IOError) {

  Options options;
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileBuilderIOErrorTest_IOError"),
+      test::PerThreadDBPath(mock_env_.get(),
+                            "BlobFileBuilderIOErrorTest_IOError"),
      0);
  options.enable_blob_files = true;
  options.blob_file_size = value_size;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  MutableCFOptions mutable_cf_options(options);

  constexpr int job_id = 1;
@@ -626,12 +626,11 @@ TEST_P(BlobFileBuilderIOErrorTest, IOError) {
  std::vector<std::string> blob_file_paths;
  std::vector<BlobFileAddition> blob_file_additions;

-  BlobFileBuilder builder(TestFileNumberGenerator(), fs_, &immutable_cf_options,
-                          &mutable_cf_options, &file_options_, job_id,
-                          column_family_id, column_family_name, io_priority,
-                          write_hint, nullptr /*IOTracer*/,
-                          nullptr /*BlobFileCompletionCallback*/,
-                          &blob_file_paths, &blob_file_additions);
+  BlobFileBuilder builder(
+      TestFileNumberGenerator(), fs_, &immutable_options, &mutable_cf_options,
+      &file_options_, job_id, column_family_id, column_family_name, io_priority,
+      write_hint, nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
+      BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);

  SyncPoint::GetInstance()->SetCallBack(sync_point_, [this](void* arg) {
    Status* const s = static_cast<Status*>(arg);
@@ -658,7 +657,7 @@ TEST_P(BlobFileBuilderIOErrorTest, IOError) {

    ASSERT_EQ(blob_file_paths.size(), 1);
    ASSERT_EQ(blob_file_paths[0],
-              BlobFileName(immutable_cf_options.cf_paths.front().path,
+              BlobFileName(immutable_options.cf_paths.front().path,
                           blob_file_number));
  }

@@ -19,20 +19,20 @@
 namespace ROCKSDB_NAMESPACE {

 BlobFileCache::BlobFileCache(Cache* cache,
-                             const ImmutableCFOptions* immutable_cf_options,
+                             const ImmutableOptions* immutable_options,
                             const FileOptions* file_options,
                             uint32_t column_family_id,
                             HistogramImpl* blob_file_read_hist,
                             const std::shared_ptr<IOTracer>& io_tracer)
    : cache_(cache),
      mutex_(kNumberOfMutexStripes, kGetSliceNPHash64UnseededFnPtr),
-      immutable_cf_options_(immutable_cf_options),
+      immutable_options_(immutable_options),
      file_options_(file_options),
      column_family_id_(column_family_id),
      blob_file_read_hist_(blob_file_read_hist),
      io_tracer_(io_tracer) {
  assert(cache_);
-  assert(immutable_cf_options_);
+  assert(immutable_options_);
  assert(file_options_);
 }

@@ -63,8 +63,8 @@ Status BlobFileCache::GetBlobFileReader(
    return Status::OK();
  }

-  assert(immutable_cf_options_);
-  Statistics* const statistics = immutable_cf_options_->statistics;
+  assert(immutable_options_);
+  Statistics* const statistics = immutable_options_->stats;

  RecordTick(statistics, NO_FILE_OPENS);

@@ -73,7 +73,7 @@ Status BlobFileCache::GetBlobFileReader(
  {
    assert(file_options_);
    const Status s = BlobFileReader::Create(
-        *immutable_cf_options_, *file_options_, column_family_id_,
+        *immutable_options_, *file_options_, column_family_id_,
        blob_file_read_hist_, blob_file_number, io_tracer_, &reader);
    if (!s.ok()) {
      RecordTick(statistics, NO_FILE_ERRORS);
@@ -14,7 +14,7 @@
 namespace ROCKSDB_NAMESPACE {

 class Cache;
-struct ImmutableCFOptions;
+struct ImmutableOptions;
 struct FileOptions;
 class HistogramImpl;
 class Status;
@@ -24,7 +24,7 @@ class IOTracer;

 class BlobFileCache {
 public:
-  BlobFileCache(Cache* cache, const ImmutableCFOptions* immutable_cf_options,
+  BlobFileCache(Cache* cache, const ImmutableOptions* immutable_options,
                const FileOptions* file_options, uint32_t column_family_id,
                HistogramImpl* blob_file_read_hist,
                const std::shared_ptr<IOTracer>& io_tracer);
@@ -40,7 +40,7 @@ class BlobFileCache {
  // Note: mutex_ below is used to guard against multiple threads racing to open
  // the same file.
  Striped<port::Mutex, Slice> mutex_;
-  const ImmutableCFOptions* immutable_cf_options_;
+  const ImmutableOptions* immutable_options_;
  const FileOptions* file_options_;
  uint32_t column_family_id_;
  HistogramImpl* blob_file_read_hist_;
@@ -29,28 +29,27 @@ namespace {

 // Creates a test blob file with a single blob in it.
 void WriteBlobFile(uint32_t column_family_id,
-                   const ImmutableCFOptions& immutable_cf_options,
+                   const ImmutableOptions& immutable_options,
                   uint64_t blob_file_number) {
-  assert(!immutable_cf_options.cf_paths.empty());
+  assert(!immutable_options.cf_paths.empty());

-  const std::string blob_file_path = BlobFileName(
-      immutable_cf_options.cf_paths.front().path, blob_file_number);
+  const std::string blob_file_path =
+      BlobFileName(immutable_options.cf_paths.front().path, blob_file_number);

  std::unique_ptr<FSWritableFile> file;
-  ASSERT_OK(NewWritableFile(immutable_cf_options.fs, blob_file_path, &file,
+  ASSERT_OK(NewWritableFile(immutable_options.fs.get(), blob_file_path, &file,
                            FileOptions()));

-  std::unique_ptr<WritableFileWriter> file_writer(
-      new WritableFileWriter(std::move(file), blob_file_path, FileOptions(),
-                             immutable_cf_options.clock));
+  std::unique_ptr<WritableFileWriter> file_writer(new WritableFileWriter(
+      std::move(file), blob_file_path, FileOptions(), immutable_options.clock));

  constexpr Statistics* statistics = nullptr;
  constexpr bool use_fsync = false;
  constexpr bool do_flush = false;

-  BlobLogWriter blob_log_writer(std::move(file_writer),
-                                immutable_cf_options.clock, statistics,
-                                blob_file_number, use_fsync, do_flush);
+  BlobLogWriter blob_log_writer(std::move(file_writer), immutable_options.clock,
+                                statistics, blob_file_number, use_fsync,
+                                do_flush);

  constexpr bool has_ttl = false;
  constexpr ExpirationRange expiration_range;
@@ -85,25 +84,26 @@ void WriteBlobFile(uint32_t column_family_id,

 class BlobFileCacheTest : public testing::Test {
 protected:
-  BlobFileCacheTest() : mock_env_(Env::Default()) {}
+  BlobFileCacheTest() { mock_env_.reset(MockEnv::Create(Env::Default())); }

-  MockEnv mock_env_;
+  std::unique_ptr<Env> mock_env_;
 };

 TEST_F(BlobFileCacheTest, GetBlobFileReader) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.statistics = CreateDBStatistics();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileCacheTest_GetBlobFileReader"),
+      test::PerThreadDBPath(mock_env_.get(),
+                            "BlobFileCacheTest_GetBlobFileReader"),
      0);
  options.enable_blob_files = true;

  constexpr uint32_t column_family_id = 1;
-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  constexpr uint64_t blob_file_number = 123;

-  WriteBlobFile(column_family_id, immutable_cf_options, blob_file_number);
+  WriteBlobFile(column_family_id, immutable_options, blob_file_number);

  constexpr size_t capacity = 10;
  std::shared_ptr<Cache> backing_cache = NewLRUCache(capacity);
@@ -111,7 +111,7 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader) {
  FileOptions file_options;
  constexpr HistogramImpl* blob_file_read_hist = nullptr;

-  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_cf_options,
+  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_options,
                                &file_options, column_family_id,
                                blob_file_read_hist, nullptr /*IOTracer*/);

@@ -136,19 +136,19 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader) {

 TEST_F(BlobFileCacheTest, GetBlobFileReader_Race) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.statistics = CreateDBStatistics();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileCacheTest_GetBlobFileReader_Race"),
      0);
  options.enable_blob_files = true;

  constexpr uint32_t column_family_id = 1;
-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  constexpr uint64_t blob_file_number = 123;

-  WriteBlobFile(column_family_id, immutable_cf_options, blob_file_number);
+  WriteBlobFile(column_family_id, immutable_options, blob_file_number);

  constexpr size_t capacity = 10;
  std::shared_ptr<Cache> backing_cache = NewLRUCache(capacity);
@@ -156,7 +156,7 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader_Race) {
  FileOptions file_options;
  constexpr HistogramImpl* blob_file_read_hist = nullptr;

-  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_cf_options,
+  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_options,
                                &file_options, column_family_id,
                                blob_file_read_hist, nullptr /*IOTracer*/);

@@ -188,10 +188,10 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader_Race) {

 TEST_F(BlobFileCacheTest, GetBlobFileReader_IOError) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.statistics = CreateDBStatistics();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileCacheTest_GetBlobFileReader_IOError"),
      0);
  options.enable_blob_files = true;
@@ -199,12 +199,12 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader_IOError) {
  constexpr size_t capacity = 10;
  std::shared_ptr<Cache> backing_cache = NewLRUCache(capacity);

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  FileOptions file_options;
  constexpr uint32_t column_family_id = 1;
  constexpr HistogramImpl* blob_file_read_hist = nullptr;

-  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_cf_options,
+  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_options,
                                &file_options, column_family_id,
                                blob_file_read_hist, nullptr /*IOTracer*/);

@@ -222,19 +222,19 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader_IOError) {

 TEST_F(BlobFileCacheTest, GetBlobFileReader_CacheFull) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.statistics = CreateDBStatistics();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileCacheTest_GetBlobFileReader_CacheFull"),
      0);
  options.enable_blob_files = true;

  constexpr uint32_t column_family_id = 1;
-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);
  constexpr uint64_t blob_file_number = 123;

-  WriteBlobFile(column_family_id, immutable_cf_options, blob_file_number);
+  WriteBlobFile(column_family_id, immutable_options, blob_file_number);

  constexpr size_t capacity = 0;
  constexpr int num_shard_bits = -1;  // determined automatically
@@ -245,7 +245,7 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader_CacheFull) {
  FileOptions file_options;
  constexpr HistogramImpl* blob_file_read_hist = nullptr;

-  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_cf_options,
+  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_options,
                                &file_options, column_family_id,
                                blob_file_read_hist, nullptr /*IOTracer*/);

@@ -9,6 +9,7 @@
 #pragma once

 #include "db/error_handler.h"
+#include "db/event_helpers.h"
 #include "file/sst_file_manager_impl.h"
 #include "rocksdb/status.h"

@@ -16,23 +17,51 @@ namespace ROCKSDB_NAMESPACE {

 class BlobFileCompletionCallback {
 public:
-#ifdef ROCKSDB_LITE
-  BlobFileCompletionCallback(SstFileManager* /*sst_file_manager*/,
-                             InstrumentedMutex* /*mutex*/,
-                             ErrorHandler* /*error_handler*/) {}
-  Status OnBlobFileCompleted(const std::string& /*file_name*/) {
-    return Status::OK();
-  }
+  BlobFileCompletionCallback(
+      SstFileManager* sst_file_manager, InstrumentedMutex* mutex,
+      ErrorHandler* error_handler, EventLogger* event_logger,
+      const std::vector<std::shared_ptr<EventListener>>& listeners,
+      const std::string& dbname)
+      : event_logger_(event_logger), listeners_(listeners), dbname_(dbname) {
+#ifndef ROCKSDB_LITE
+    sst_file_manager_ = sst_file_manager;
+    mutex_ = mutex;
+    error_handler_ = error_handler;
 #else
-  BlobFileCompletionCallback(SstFileManager* sst_file_manager,
-                             InstrumentedMutex* mutex,
-                             ErrorHandler* error_handler)
-      : sst_file_manager_(sst_file_manager),
-        mutex_(mutex),
-        error_handler_(error_handler) {}
+    (void)sst_file_manager;
+    (void)mutex;
+    (void)error_handler;
+#endif  // ROCKSDB_LITE
+  }

-  Status OnBlobFileCompleted(const std::string& file_name) {
+  void OnBlobFileCreationStarted(const std::string& file_name,
+                                 const std::string& column_family_name,
+                                 int job_id,
+                                 BlobFileCreationReason creation_reason) {
+#ifndef ROCKSDB_LITE
+    // Notify the listeners.
+    EventHelpers::NotifyBlobFileCreationStarted(listeners_, dbname_,
+                                                column_family_name, file_name,
+                                                job_id, creation_reason);
+#else
+    (void)file_name;
+    (void)column_family_name;
+    (void)job_id;
+    (void)creation_reason;
+#endif
+  }
+
+  Status OnBlobFileCompleted(const std::string& file_name,
+                             const std::string& column_family_name, int job_id,
+                             uint64_t file_number,
+                             BlobFileCreationReason creation_reason,
+                             const Status& report_status,
+                             const std::string& checksum_value,
+                             const std::string& checksum_method,
+                             uint64_t blob_count, uint64_t blob_bytes) {
    Status s;
+
+#ifndef ROCKSDB_LITE
    auto sfm = static_cast<SstFileManagerImpl*>(sst_file_manager_);
    if (sfm) {
      // Report new blob files to SstFileManagerImpl
@@ -45,13 +74,28 @@ class BlobFileCompletionCallback {
        error_handler_->SetBGError(s, BackgroundErrorReason::kFlush);
      }
    }
+#endif  // !ROCKSDB_LITE
+
+    // Notify the listeners.
+    EventHelpers::LogAndNotifyBlobFileCreationFinished(
+        event_logger_, listeners_, dbname_, column_family_name, file_name,
+        job_id, file_number, creation_reason,
+        (!report_status.ok() ? report_status : s),
+        (checksum_value.empty() ? kUnknownFileChecksum : checksum_value),
+        (checksum_method.empty() ? kUnknownFileChecksumFuncName
+                                 : checksum_method),
+        blob_count, blob_bytes);
    return s;
  }

 private:
+#ifndef ROCKSDB_LITE
  SstFileManager* sst_file_manager_;
  InstrumentedMutex* mutex_;
  ErrorHandler* error_handler_;
 #endif  // ROCKSDB_LITE
+  EventLogger* event_logger_;
+  std::vector<std::shared_ptr<EventListener>> listeners_;
+  std::string dbname_;
 };
 }  // namespace ROCKSDB_NAMESPACE
@@ -8,7 +8,13 @@
 #include <ostream>
 #include <sstream>

+#include "db/blob/blob_log_format.h"
+#include "rocksdb/slice.h"
+
 namespace ROCKSDB_NAMESPACE {
+uint64_t SharedBlobFileMetaData::GetBlobFileSize() const {
+  return BlobLogHeader::kSize + total_blob_bytes_ + BlobLogFooter::kSize;
+}

 std::string SharedBlobFileMetaData::DebugString() const {
  std::ostringstream oss;
@@ -23,7 +29,8 @@ std::ostream& operator<<(std::ostream& os,
     << " total_blob_count: " << shared_meta.GetTotalBlobCount()
     << " total_blob_bytes: " << shared_meta.GetTotalBlobBytes()
     << " checksum_method: " << shared_meta.GetChecksumMethod()
-     << " checksum_value: " << shared_meta.GetChecksumValue();
+     << " checksum_value: "
+     << Slice(shared_meta.GetChecksumValue()).ToString(/* hex */ true);

  return os;
 }
@@ -51,6 +51,7 @@ class SharedBlobFileMetaData {
  SharedBlobFileMetaData(SharedBlobFileMetaData&&) = delete;
  SharedBlobFileMetaData& operator=(SharedBlobFileMetaData&&) = delete;

+  uint64_t GetBlobFileSize() const;
  uint64_t GetBlobFileNumber() const { return blob_file_number_; }
  uint64_t GetTotalBlobCount() const { return total_blob_count_; }
  uint64_t GetTotalBlobBytes() const { return total_blob_bytes_; }
@@ -112,6 +113,11 @@ class BlobFileMetaData {
    return shared_meta_;
  }

+  uint64_t GetBlobFileSize() const {
+    assert(shared_meta_);
+    return shared_meta_->GetBlobFileSize();
+  }
+
  uint64_t GetBlobFileNumber() const {
    assert(shared_meta_);
    return shared_meta_->GetBlobFileNumber();
@@ -9,7 +9,9 @@
 #include <string>

 #include "db/blob/blob_log_format.h"
+#include "file/file_prefetch_buffer.h"
 #include "file/filename.h"
+#include "monitoring/statistics.h"
 #include "options/cf_options.h"
 #include "rocksdb/file_system.h"
 #include "rocksdb/slice.h"
@@ -17,14 +19,14 @@
 #include "test_util/sync_point.h"
 #include "util/compression.h"
 #include "util/crc32c.h"
+#include "util/stop_watch.h"

 namespace ROCKSDB_NAMESPACE {

 Status BlobFileReader::Create(
-    const ImmutableCFOptions& immutable_cf_options,
-    const FileOptions& file_options, uint32_t column_family_id,
-    HistogramImpl* blob_file_read_hist, uint64_t blob_file_number,
-    const std::shared_ptr<IOTracer>& io_tracer,
+    const ImmutableOptions& immutable_options, const FileOptions& file_options,
+    uint32_t column_family_id, HistogramImpl* blob_file_read_hist,
+    uint64_t blob_file_number, const std::shared_ptr<IOTracer>& io_tracer,
    std::unique_ptr<BlobFileReader>* blob_file_reader) {
  assert(blob_file_reader);
  assert(!*blob_file_reader);
@@ -34,7 +36,7 @@ Status BlobFileReader::Create(

  {
    const Status s =
-        OpenFile(immutable_cf_options, file_options, blob_file_read_hist,
+        OpenFile(immutable_options, file_options, blob_file_read_hist,
                 blob_file_number, io_tracer, &file_size, &file_reader);
    if (!s.ok()) {
      return s;
@@ -43,44 +45,47 @@ Status BlobFileReader::Create(

  assert(file_reader);

+  Statistics* const statistics = immutable_options.stats;
+
  CompressionType compression_type = kNoCompression;

  {
-    const Status s =
-        ReadHeader(file_reader.get(), column_family_id, &compression_type);
+    const Status s = ReadHeader(file_reader.get(), column_family_id, statistics,
+                                &compression_type);
    if (!s.ok()) {
      return s;
    }
  }

  {
-    const Status s = ReadFooter(file_size, file_reader.get());
+    const Status s = ReadFooter(file_reader.get(), file_size, statistics);
    if (!s.ok()) {
      return s;
    }
  }

  blob_file_reader->reset(
-      new BlobFileReader(std::move(file_reader), file_size, compression_type));
+      new BlobFileReader(std::move(file_reader), file_size, compression_type,
+                         immutable_options.clock, statistics));

  return Status::OK();
 }

 Status BlobFileReader::OpenFile(
-    const ImmutableCFOptions& immutable_cf_options,
-    const FileOptions& file_opts, HistogramImpl* blob_file_read_hist,
-    uint64_t blob_file_number, const std::shared_ptr<IOTracer>& io_tracer,
-    uint64_t* file_size, std::unique_ptr<RandomAccessFileReader>* file_reader) {
+    const ImmutableOptions& immutable_options, const FileOptions& file_opts,
+    HistogramImpl* blob_file_read_hist, uint64_t blob_file_number,
+    const std::shared_ptr<IOTracer>& io_tracer, uint64_t* file_size,
+    std::unique_ptr<RandomAccessFileReader>* file_reader) {
  assert(file_size);
  assert(file_reader);

-  const auto& cf_paths = immutable_cf_options.cf_paths;
+  const auto& cf_paths = immutable_options.cf_paths;
  assert(!cf_paths.empty());

  const std::string blob_file_path =
      BlobFileName(cf_paths.front().path, blob_file_number);

-  FileSystem* const fs = immutable_cf_options.fs;
+  FileSystem* const fs = immutable_options.fs.get();
  assert(fs);

  constexpr IODebugContext* dbg = nullptr;
@@ -113,21 +118,22 @@ Status BlobFileReader::OpenFile(

  assert(file);

-  if (immutable_cf_options.advise_random_on_open) {
+  if (immutable_options.advise_random_on_open) {
    file->Hint(FSRandomAccessFile::kRandom);
  }

  file_reader->reset(new RandomAccessFileReader(
-      std::move(file), blob_file_path, immutable_cf_options.clock, io_tracer,
-      immutable_cf_options.statistics, BLOB_DB_BLOB_FILE_READ_MICROS,
-      blob_file_read_hist, immutable_cf_options.rate_limiter.get(),
-      immutable_cf_options.listeners));
+      std::move(file), blob_file_path, immutable_options.clock, io_tracer,
+      immutable_options.stats, BLOB_DB_BLOB_FILE_READ_MICROS,
+      blob_file_read_hist, immutable_options.rate_limiter.get(),
+      immutable_options.listeners));

  return Status::OK();
 }

 Status BlobFileReader::ReadHeader(const RandomAccessFileReader* file_reader,
                                  uint32_t column_family_id,
+                                  Statistics* statistics,
                                  CompressionType* compression_type) {
  assert(file_reader);
  assert(compression_type);
@@ -142,8 +148,10 @@ Status BlobFileReader::ReadHeader(const RandomAccessFileReader* file_reader,
    constexpr uint64_t read_offset = 0;
    constexpr size_t read_size = BlobLogHeader::kSize;

+    // TODO: rate limit reading headers from blob files.
    const Status s = ReadFromFile(file_reader, read_offset, read_size,
-                                  &header_slice, &buf, &aligned_buf);
+                                  statistics, &header_slice, &buf, &aligned_buf,
+                                  Env::IO_TOTAL /* rate_limiter_priority */);
    if (!s.ok()) {
      return s;
    }
@@ -176,8 +184,8 @@ Status BlobFileReader::ReadHeader(const RandomAccessFileReader* file_reader,
  return Status::OK();
 }

-Status BlobFileReader::ReadFooter(uint64_t file_size,
-                                  const RandomAccessFileReader* file_reader) {
+Status BlobFileReader::ReadFooter(const RandomAccessFileReader* file_reader,
+                                  uint64_t file_size, Statistics* statistics) {
  assert(file_size >= BlobLogHeader::kSize + BlobLogFooter::kSize);
  assert(file_reader);

@@ -191,8 +199,10 @@ Status BlobFileReader::ReadFooter(uint64_t file_size,
    const uint64_t read_offset = file_size - BlobLogFooter::kSize;
    constexpr size_t read_size = BlobLogFooter::kSize;

+    // TODO: rate limit reading footers from blob files.
    const Status s = ReadFromFile(file_reader, read_offset, read_size,
-                                  &footer_slice, &buf, &aligned_buf);
+                                  statistics, &footer_slice, &buf, &aligned_buf,
+                                  Env::IO_TOTAL /* rate_limiter_priority */);
    if (!s.ok()) {
      return s;
    }
@@ -221,27 +231,30 @@ Status BlobFileReader::ReadFooter(uint64_t file_size,

 Status BlobFileReader::ReadFromFile(const RandomAccessFileReader* file_reader,
                                    uint64_t read_offset, size_t read_size,
-                                    Slice* slice, Buffer* buf,
-                                    AlignedBuf* aligned_buf) {
+                                    Statistics* statistics, Slice* slice,
+                                    Buffer* buf, AlignedBuf* aligned_buf,
+                                    Env::IOPriority rate_limiter_priority) {
  assert(slice);
  assert(buf);
  assert(aligned_buf);

  assert(file_reader);

+  RecordTick(statistics, BLOB_DB_BLOB_FILE_BYTES_READ, read_size);
+
  Status s;

  if (file_reader->use_direct_io()) {
    constexpr char* scratch = nullptr;

    s = file_reader->Read(IOOptions(), read_offset, read_size, slice, scratch,
-                          aligned_buf);
+                          aligned_buf, rate_limiter_priority);
  } else {
    buf->reset(new char[read_size]);
    constexpr AlignedBuf* aligned_scratch = nullptr;

    s = file_reader->Read(IOOptions(), read_offset, read_size, slice,
-                          buf->get(), aligned_scratch);
+                          buf->get(), aligned_scratch, rate_limiter_priority);
  }

  if (!s.ok()) {
@@ -257,10 +270,13 @@ Status BlobFileReader::ReadFromFile(const RandomAccessFileReader* file_reader,

 BlobFileReader::BlobFileReader(
    std::unique_ptr<RandomAccessFileReader>&& file_reader, uint64_t file_size,
-    CompressionType compression_type)
+    CompressionType compression_type, SystemClock* clock,
+    Statistics* statistics)
    : file_reader_(std::move(file_reader)),
      file_size_(file_size),
-      compression_type_(compression_type) {
+      compression_type_(compression_type),
+      clock_(clock),
+      statistics_(statistics) {
  assert(file_reader_);
 }

@@ -270,6 +286,7 @@ Status BlobFileReader::GetBlob(const ReadOptions& read_options,
                               const Slice& user_key, uint64_t offset,
                               uint64_t value_size,
                               CompressionType compression_type,
+                               FilePrefetchBuffer* prefetch_buffer,
                               PinnableSlice* value,
                               uint64_t* bytes_read) const {
  assert(value);
@@ -301,20 +318,36 @@ Status BlobFileReader::GetBlob(const ReadOptions& read_options,
  Buffer buf;
  AlignedBuf aligned_buf;

-  {
-    TEST_SYNC_POINT("BlobFileReader::GetBlob:ReadFromFile");
+  bool prefetched = false;

-    const Status s = ReadFromFile(file_reader_.get(), record_offset,
-                                  static_cast<size_t>(record_size),
-                                  &record_slice, &buf, &aligned_buf);
+  if (prefetch_buffer) {
+    Status s;
+    constexpr bool for_compaction = true;
+
+    prefetched = prefetch_buffer->TryReadFromCache(
+        IOOptions(), file_reader_.get(), record_offset,
+        static_cast<size_t>(record_size), &record_slice, &s,
+        read_options.rate_limiter_priority, for_compaction);
    if (!s.ok()) {
      return s;
    }
-
-    TEST_SYNC_POINT_CALLBACK("BlobFileReader::GetBlob:TamperWithResult",
-                             &record_slice);
  }

+  if (!prefetched) {
+    TEST_SYNC_POINT("BlobFileReader::GetBlob:ReadFromFile");
+
+    const Status s = ReadFromFile(file_reader_.get(), record_offset,
+                                  static_cast<size_t>(record_size), statistics_,
+                                  &record_slice, &buf, &aligned_buf,
+                                  read_options.rate_limiter_priority);
+    if (!s.ok()) {
+      return s;
+    }
+  }
+
+  TEST_SYNC_POINT_CALLBACK("BlobFileReader::GetBlob:TamperWithResult",
+                           &record_slice);
+
  if (read_options.verify_checksums) {
    const Status s = VerifyBlob(record_slice, user_key, value_size);
    if (!s.ok()) {
@@ -325,8 +358,8 @@ Status BlobFileReader::GetBlob(const ReadOptions& read_options,
  const Slice value_slice(record_slice.data() + adjustment, value_size);

  {
-    const Status s =
-        UncompressBlobIfNeeded(value_slice, compression_type, value);
+    const Status s = UncompressBlobIfNeeded(value_slice, compression_type,
+                                            clock_, statistics_, value);
    if (!s.ok()) {
      return s;
    }
@@ -339,6 +372,125 @@ Status BlobFileReader::GetBlob(const ReadOptions& read_options,
  return Status::OK();
 }

+void BlobFileReader::MultiGetBlob(
+    const ReadOptions& read_options,
+    const autovector<std::reference_wrapper<const Slice>>& user_keys,
+    const autovector<uint64_t>& offsets,
+    const autovector<uint64_t>& value_sizes, autovector<Status*>& statuses,
+    autovector<PinnableSlice*>& values, uint64_t* bytes_read) const {
+  const size_t num_blobs = user_keys.size();
+  assert(num_blobs > 0);
+  assert(num_blobs == offsets.size());
+  assert(num_blobs == value_sizes.size());
+  assert(num_blobs == statuses.size());
+  assert(num_blobs == values.size());
+
+#ifndef NDEBUG
+  for (size_t i = 0; i < offsets.size() - 1; ++i) {
+    assert(offsets[i] <= offsets[i + 1]);
+  }
+#endif  // !NDEBUG
+
+  std::vector<FSReadRequest> read_reqs(num_blobs);
+  autovector<uint64_t> adjustments;
+  uint64_t total_len = 0;
+  for (size_t i = 0; i < num_blobs; ++i) {
+    const size_t key_size = user_keys[i].get().size();
+    assert(IsValidBlobOffset(offsets[i], key_size, value_sizes[i], file_size_));
+    const uint64_t adjustment =
+        read_options.verify_checksums
+            ? BlobLogRecord::CalculateAdjustmentForRecordHeader(key_size)
+            : 0;
+    assert(offsets[i] >= adjustment);
+    adjustments.push_back(adjustment);
+    read_reqs[i].offset = offsets[i] - adjustment;
+    read_reqs[i].len = value_sizes[i] + adjustment;
+    total_len += read_reqs[i].len;
+  }
+
+  RecordTick(statistics_, BLOB_DB_BLOB_FILE_BYTES_READ, total_len);
+
+  Buffer buf;
+  AlignedBuf aligned_buf;
+
+  Status s;
+  bool direct_io = file_reader_->use_direct_io();
+  if (direct_io) {
+    for (size_t i = 0; i < read_reqs.size(); ++i) {
+      read_reqs[i].scratch = nullptr;
+    }
+  } else {
+    buf.reset(new char[total_len]);
+    std::ptrdiff_t pos = 0;
+    for (size_t i = 0; i < read_reqs.size(); ++i) {
+      read_reqs[i].scratch = buf.get() + pos;
+      pos += read_reqs[i].len;
+    }
+  }
+  TEST_SYNC_POINT("BlobFileReader::MultiGetBlob:ReadFromFile");
+  s = file_reader_->MultiRead(IOOptions(), read_reqs.data(), read_reqs.size(),
+                              direct_io ? &aligned_buf : nullptr,
+                              read_options.rate_limiter_priority);
+  if (!s.ok()) {
+    for (auto& req : read_reqs) {
+      req.status.PermitUncheckedError();
+    }
+    for (size_t i = 0; i < num_blobs; ++i) {
+      assert(statuses[i]);
+      *statuses[i] = s;
+    }
+    return;
+  }
+
+  assert(s.ok());
+  for (size_t i = 0; i < num_blobs; ++i) {
+    auto& req = read_reqs[i];
+    assert(statuses[i]);
+    if (req.status.ok() && req.result.size() != req.len) {
+      req.status = IOStatus::Corruption("Failed to read data from blob file");
+    }
+    *statuses[i] = req.status;
+  }
+
+  if (read_options.verify_checksums) {
+    for (size_t i = 0; i < num_blobs; ++i) {
+      assert(statuses[i]);
+      if (!statuses[i]->ok()) {
+        continue;
+      }
+      const Slice& record_slice = read_reqs[i].result;
+      s = VerifyBlob(record_slice, user_keys[i], value_sizes[i]);
+      if (!s.ok()) {
+        assert(statuses[i]);
+        *statuses[i] = s;
+      }
+    }
+  }
+
+  for (size_t i = 0; i < num_blobs; ++i) {
+    assert(statuses[i]);
+    if (!statuses[i]->ok()) {
+      continue;
+    }
+    const Slice& record_slice = read_reqs[i].result;
+    const Slice value_slice(record_slice.data() + adjustments[i],
+                            value_sizes[i]);
+    s = UncompressBlobIfNeeded(value_slice, compression_type_, clock_,
+                               statistics_, values[i]);
+    if (!s.ok()) {
+      *statuses[i] = s;
+    }
+  }
+
+  if (bytes_read) {
+    uint64_t total_bytes = 0;
+    for (const auto& req : read_reqs) {
+      total_bytes += req.result.size();
+    }
+    *bytes_read = total_bytes;
+  }
+}
+
 Status BlobFileReader::VerifyBlob(const Slice& record_slice,
                                  const Slice& user_key, uint64_t value_size) {
  BlobLogRecord record;
@@ -383,6 +535,8 @@ Status BlobFileReader::VerifyBlob(const Slice& record_slice,

 Status BlobFileReader::UncompressBlobIfNeeded(const Slice& value_slice,
                                              CompressionType compression_type,
+                                              SystemClock* clock,
+                                              Statistics* statistics,
                                              PinnableSlice* value) {
  assert(value);

@@ -400,9 +554,14 @@ Status BlobFileReader::UncompressBlobIfNeeded(const Slice& value_slice,
  constexpr uint32_t compression_format_version = 2;
  constexpr MemoryAllocator* allocator = nullptr;

-  CacheAllocationPtr output =
-      UncompressData(info, value_slice.data(), value_slice.size(),
-                     &uncompressed_size, compression_format_version, allocator);
+  CacheAllocationPtr output;
+
+  {
+    StopWatch stop_watch(clock, statistics, BLOB_DB_DECOMPRESSION_MICROS);
+    output = UncompressData(info, value_slice.data(), value_slice.size(),
+                            &uncompressed_size, compression_format_version,
+                            allocator);
+  }

  TEST_SYNC_POINT_CALLBACK(
      "BlobFileReader::UncompressBlobIfNeeded:TamperWithResult", &output);
@@ -11,20 +11,23 @@
 #include "file/random_access_file_reader.h"
 #include "rocksdb/compression_type.h"
 #include "rocksdb/rocksdb_namespace.h"
+#include "util/autovector.h"

 namespace ROCKSDB_NAMESPACE {

 class Status;
-struct ImmutableCFOptions;
+struct ImmutableOptions;
 struct FileOptions;
 class HistogramImpl;
 struct ReadOptions;
 class Slice;
+class FilePrefetchBuffer;
 class PinnableSlice;
+class Statistics;

 class BlobFileReader {
 public:
-  static Status Create(const ImmutableCFOptions& immutable_cf_options,
+  static Status Create(const ImmutableOptions& immutable_options,
                       const FileOptions& file_options,
                       uint32_t column_family_id,
                       HistogramImpl* blob_file_read_hist,
@@ -39,14 +42,28 @@ class BlobFileReader {

  Status GetBlob(const ReadOptions& read_options, const Slice& user_key,
                 uint64_t offset, uint64_t value_size,
-                 CompressionType compression_type, PinnableSlice* value,
+                 CompressionType compression_type,
+                 FilePrefetchBuffer* prefetch_buffer, PinnableSlice* value,
                 uint64_t* bytes_read) const;

+  // offsets must be sorted in ascending order by caller.
+  void MultiGetBlob(
+      const ReadOptions& read_options,
+      const autovector<std::reference_wrapper<const Slice>>& user_keys,
+      const autovector<uint64_t>& offsets,
+      const autovector<uint64_t>& value_sizes, autovector<Status*>& statuses,
+      autovector<PinnableSlice*>& values, uint64_t* bytes_read) const;
+
+  CompressionType GetCompressionType() const { return compression_type_; }
+
+  uint64_t GetFileSize() const { return file_size_; }
+
 private:
  BlobFileReader(std::unique_ptr<RandomAccessFileReader>&& file_reader,
-                 uint64_t file_size, CompressionType compression_type);
+                 uint64_t file_size, CompressionType compression_type,
+                 SystemClock* clock, Statistics* statistics);

-  static Status OpenFile(const ImmutableCFOptions& immutable_cf_options,
+  static Status OpenFile(const ImmutableOptions& immutable_options,
                         const FileOptions& file_opts,
                         HistogramImpl* blob_file_read_hist,
                         uint64_t blob_file_number,
@@ -55,24 +72,27 @@ class BlobFileReader {
                         std::unique_ptr<RandomAccessFileReader>* file_reader);

  static Status ReadHeader(const RandomAccessFileReader* file_reader,
-                           uint32_t column_family_id,
+                           uint32_t column_family_id, Statistics* statistics,
                           CompressionType* compression_type);

-  static Status ReadFooter(uint64_t file_size,
-                           const RandomAccessFileReader* file_reader);
+  static Status ReadFooter(const RandomAccessFileReader* file_reader,
+                           uint64_t file_size, Statistics* statistics);

  using Buffer = std::unique_ptr<char[]>;

  static Status ReadFromFile(const RandomAccessFileReader* file_reader,
                             uint64_t read_offset, size_t read_size,
-                             Slice* slice, Buffer* buf,
-                             AlignedBuf* aligned_buf);
+                             Statistics* statistics, Slice* slice, Buffer* buf,
+                             AlignedBuf* aligned_buf,
+                             Env::IOPriority rate_limiter_priority);

  static Status VerifyBlob(const Slice& record_slice, const Slice& user_key,
                           uint64_t value_size);

  static Status UncompressBlobIfNeeded(const Slice& value_slice,
                                       CompressionType compression_type,
+                                       SystemClock* clock,
+                                       Statistics* statistics,
                                       PinnableSlice* value);

  static void SaveValue(const Slice& src, PinnableSlice* dst);
@@ -80,6 +100,8 @@ class BlobFileReader {
  std::unique_ptr<RandomAccessFileReader> file_reader_;
  uint64_t file_size_;
  CompressionType compression_type_;
+  SystemClock* clock_;
+  Statistics* statistics_;
 };

 }  // namespace ROCKSDB_NAMESPACE
@@ -27,137 +27,194 @@ namespace ROCKSDB_NAMESPACE {

 namespace {

-// Creates a test blob file with a single blob in it. Note: this method
-// makes it possible to test various corner cases by allowing the caller
-// to specify the contents of various blob file header/footer fields.
-void WriteBlobFile(const ImmutableCFOptions& immutable_cf_options,
+// Creates a test blob file with `num` blobs in it.
+void WriteBlobFile(const ImmutableOptions& immutable_options,
                   uint32_t column_family_id, bool has_ttl,
                   const ExpirationRange& expiration_range_header,
                   const ExpirationRange& expiration_range_footer,
-                   uint64_t blob_file_number, const Slice& key,
-                   const Slice& blob, CompressionType compression_type,
-                   uint64_t* blob_offset, uint64_t* blob_size) {
-  assert(!immutable_cf_options.cf_paths.empty());
-  assert(blob_offset);
-  assert(blob_size);
-
-  const std::string blob_file_path = BlobFileName(
-      immutable_cf_options.cf_paths.front().path, blob_file_number);
+                   uint64_t blob_file_number, const std::vector<Slice>& keys,
+                   const std::vector<Slice>& blobs, CompressionType compression,
+                   std::vector<uint64_t>& blob_offsets,
+                   std::vector<uint64_t>& blob_sizes) {
+  assert(!immutable_options.cf_paths.empty());
+  size_t num = keys.size();
+  assert(num == blobs.size());
+  assert(num == blob_offsets.size());
+  assert(num == blob_sizes.size());

+  const std::string blob_file_path =
+      BlobFileName(immutable_options.cf_paths.front().path, blob_file_number);
  std::unique_ptr<FSWritableFile> file;
-  ASSERT_OK(NewWritableFile(immutable_cf_options.fs, blob_file_path, &file,
+  ASSERT_OK(NewWritableFile(immutable_options.fs.get(), blob_file_path, &file,
                            FileOptions()));

-  std::unique_ptr<WritableFileWriter> file_writer(
-      new WritableFileWriter(std::move(file), blob_file_path, FileOptions(),
-                             immutable_cf_options.clock));
+  std::unique_ptr<WritableFileWriter> file_writer(new WritableFileWriter(
+      std::move(file), blob_file_path, FileOptions(), immutable_options.clock));

  constexpr Statistics* statistics = nullptr;
  constexpr bool use_fsync = false;
  constexpr bool do_flush = false;

-  BlobLogWriter blob_log_writer(std::move(file_writer),
-                                immutable_cf_options.clock, statistics,
-                                blob_file_number, use_fsync, do_flush);
+  BlobLogWriter blob_log_writer(std::move(file_writer), immutable_options.clock,
+                                statistics, blob_file_number, use_fsync,
+                                do_flush);

-  BlobLogHeader header(column_family_id, compression_type, has_ttl,
+  BlobLogHeader header(column_family_id, compression, has_ttl,
                       expiration_range_header);

  ASSERT_OK(blob_log_writer.WriteHeader(header));

-  std::string compressed_blob;
-  Slice blob_to_write;
-
-  if (compression_type == kNoCompression) {
-    blob_to_write = blob;
-    *blob_size = blob.size();
+  std::vector<std::string> compressed_blobs(num);
+  std::vector<Slice> blobs_to_write(num);
+  if (kNoCompression == compression) {
+    for (size_t i = 0; i < num; ++i) {
+      blobs_to_write[i] = blobs[i];
+      blob_sizes[i] = blobs[i].size();
+    }
  } else {
    CompressionOptions opts;
-    CompressionContext context(compression_type);
+    CompressionContext context(compression);
    constexpr uint64_t sample_for_compression = 0;
-
    CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(),
-                         compression_type, sample_for_compression);
+                         compression, sample_for_compression);

    constexpr uint32_t compression_format_version = 2;

-    ASSERT_TRUE(
-        CompressData(blob, info, compression_format_version, &compressed_blob));
-
-    blob_to_write = compressed_blob;
-    *blob_size = compressed_blob.size();
+    for (size_t i = 0; i < num; ++i) {
+      ASSERT_TRUE(CompressData(blobs[i], info, compression_format_version,
+                               &compressed_blobs[i]));
+      blobs_to_write[i] = compressed_blobs[i];
+      blob_sizes[i] = compressed_blobs[i].size();
+    }
  }

-  uint64_t key_offset = 0;
-
-  ASSERT_OK(
-      blob_log_writer.AddRecord(key, blob_to_write, &key_offset, blob_offset));
+  for (size_t i = 0; i < num; ++i) {
+    uint64_t key_offset = 0;
+    ASSERT_OK(blob_log_writer.AddRecord(keys[i], blobs_to_write[i], &key_offset,
+                                        &blob_offsets[i]));
+  }

  BlobLogFooter footer;
-  footer.blob_count = 1;
+  footer.blob_count = num;
  footer.expiration_range = expiration_range_footer;

  std::string checksum_method;
  std::string checksum_value;
-
  ASSERT_OK(
      blob_log_writer.AppendFooter(footer, &checksum_method, &checksum_value));
 }

+// Creates a test blob file with a single blob in it. Note: this method
+// makes it possible to test various corner cases by allowing the caller
+// to specify the contents of various blob file header/footer fields.
+void WriteBlobFile(const ImmutableOptions& immutable_options,
+                   uint32_t column_family_id, bool has_ttl,
+                   const ExpirationRange& expiration_range_header,
+                   const ExpirationRange& expiration_range_footer,
+                   uint64_t blob_file_number, const Slice& key,
+                   const Slice& blob, CompressionType compression,
+                   uint64_t* blob_offset, uint64_t* blob_size) {
+  std::vector<Slice> keys{key};
+  std::vector<Slice> blobs{blob};
+  std::vector<uint64_t> blob_offsets{0};
+  std::vector<uint64_t> blob_sizes{0};
+  WriteBlobFile(immutable_options, column_family_id, has_ttl,
+                expiration_range_header, expiration_range_footer,
+                blob_file_number, keys, blobs, compression, blob_offsets,
+                blob_sizes);
+  if (blob_offset) {
+    *blob_offset = blob_offsets[0];
+  }
+  if (blob_size) {
+    *blob_size = blob_sizes[0];
+  }
+}
+
 }  // anonymous namespace

 class BlobFileReaderTest : public testing::Test {
 protected:
-  BlobFileReaderTest() : mock_env_(Env::Default()) {}
-
-  MockEnv mock_env_;
+  BlobFileReaderTest() { mock_env_.reset(MockEnv::Create(Env::Default())); }
+  std::unique_ptr<Env> mock_env_;
 };

 TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileReaderTest_CreateReaderAndGetBlob"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
  constexpr ExpirationRange expiration_range;
  constexpr uint64_t blob_file_number = 1;
-  constexpr char key[] = "key";
-  constexpr char blob[] = "blob";
+  constexpr size_t num_blobs = 3;
+  const std::vector<std::string> key_strs = {"key1", "key2", "key3"};
+  const std::vector<std::string> blob_strs = {"blob1", "blob2", "blob3"};

-  uint64_t blob_offset = 0;
-  uint64_t blob_size = 0;
+  const std::vector<Slice> keys = {key_strs[0], key_strs[1], key_strs[2]};
+  const std::vector<Slice> blobs = {blob_strs[0], blob_strs[1], blob_strs[2]};

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
-                kNoCompression, &blob_offset, &blob_size);
+  std::vector<uint64_t> blob_offsets(keys.size());
+  std::vector<uint64_t> blob_sizes(keys.size());
+
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, keys, blobs, kNoCompression,
+                blob_offsets, blob_sizes);

  constexpr HistogramImpl* blob_file_read_hist = nullptr;

  std::unique_ptr<BlobFileReader> reader;

  ASSERT_OK(BlobFileReader::Create(
-      immutable_cf_options, FileOptions(), column_family_id,
-      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader));
+      immutable_options, FileOptions(), column_family_id, blob_file_read_hist,
+      blob_file_number, nullptr /*IOTracer*/, &reader));

  // Make sure the blob can be retrieved with and without checksum verification
  ReadOptions read_options;
  read_options.verify_checksums = false;

+  constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
+
  {
    PinnableSlice value;
    uint64_t bytes_read = 0;

-    ASSERT_OK(reader->GetBlob(read_options, key, blob_offset, blob_size,
-                              kNoCompression, &value, &bytes_read));
-    ASSERT_EQ(value, blob);
-    ASSERT_EQ(bytes_read, blob_size);
+    ASSERT_OK(reader->GetBlob(read_options, keys[0], blob_offsets[0],
+                              blob_sizes[0], kNoCompression, prefetch_buffer,
+                              &value, &bytes_read));
+    ASSERT_EQ(value, blobs[0]);
+    ASSERT_EQ(bytes_read, blob_sizes[0]);
+
+    // MultiGetBlob
+    bytes_read = 0;
+    size_t total_size = 0;
+    autovector<std::reference_wrapper<const Slice>> key_refs;
+    for (const auto& key_ref : keys) {
+      key_refs.emplace_back(std::cref(key_ref));
+    }
+    autovector<uint64_t> offsets{blob_offsets[0], blob_offsets[1],
+                                 blob_offsets[2]};
+    autovector<uint64_t> sizes{blob_sizes[0], blob_sizes[1], blob_sizes[2]};
+    std::array<Status, num_blobs> statuses_buf;
+    autovector<Status*> statuses{&statuses_buf[0], &statuses_buf[1],
+                                 &statuses_buf[2]};
+    std::array<PinnableSlice, num_blobs> value_buf;
+    autovector<PinnableSlice*> values{&value_buf[0], &value_buf[1],
+                                      &value_buf[2]};
+    reader->MultiGetBlob(read_options, key_refs, offsets, sizes, statuses,
+                         values, &bytes_read);
+    for (size_t i = 0; i < num_blobs; ++i) {
+      ASSERT_OK(statuses_buf[i]);
+      ASSERT_EQ(value_buf[i], blobs[i]);
+      total_size += blob_sizes[i];
+    }
+    ASSERT_EQ(bytes_read, total_size);
  }

  read_options.verify_checksums = true;
@@ -166,14 +223,15 @@ TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {
    PinnableSlice value;
    uint64_t bytes_read = 0;

-    ASSERT_OK(reader->GetBlob(read_options, key, blob_offset, blob_size,
-                              kNoCompression, &value, &bytes_read));
-    ASSERT_EQ(value, blob);
+    ASSERT_OK(reader->GetBlob(read_options, keys[1], blob_offsets[1],
+                              blob_sizes[1], kNoCompression, prefetch_buffer,
+                              &value, &bytes_read));
+    ASSERT_EQ(value, blobs[1]);

-    constexpr uint64_t key_size = sizeof(key) - 1;
+    const uint64_t key_size = keys[1].size();
    ASSERT_EQ(bytes_read,
              BlobLogRecord::CalculateAdjustmentForRecordHeader(key_size) +
-                  blob_size);
+                  blob_sizes[1]);
  }

  // Invalid offset (too close to start of file)
@@ -182,8 +240,9 @@ TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
-                    ->GetBlob(read_options, key, blob_offset - 1, blob_size,
-                              kNoCompression, &value, &bytes_read)
+                    ->GetBlob(read_options, keys[0], blob_offsets[0] - 1,
+                              blob_sizes[0], kNoCompression, prefetch_buffer,
+                              &value, &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -194,8 +253,9 @@ TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
-                    ->GetBlob(read_options, key, blob_offset + 1, blob_size,
-                              kNoCompression, &value, &bytes_read)
+                    ->GetBlob(read_options, keys[2], blob_offsets[2] + 1,
+                              blob_sizes[2], kNoCompression, prefetch_buffer,
+                              &value, &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -206,8 +266,9 @@ TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
-                    ->GetBlob(read_options, key, blob_offset, blob_size, kZSTD,
-                              &value, &bytes_read)
+                    ->GetBlob(read_options, keys[0], blob_offsets[0],
+                              blob_sizes[0], kZSTD, prefetch_buffer, &value,
+                              &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -220,23 +281,82 @@ TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {

    ASSERT_TRUE(reader
                    ->GetBlob(read_options, shorter_key,
-                              blob_offset - (sizeof(key) - sizeof(shorter_key)),
-                              blob_size, kNoCompression, &value, &bytes_read)
+                              blob_offsets[0] -
+                                  (keys[0].size() - sizeof(shorter_key) + 1),
+                              blob_sizes[0], kNoCompression, prefetch_buffer,
+                              &value, &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
+
+    // MultiGetBlob
+    autovector<std::reference_wrapper<const Slice>> key_refs;
+    for (const auto& key_ref : keys) {
+      key_refs.emplace_back(std::cref(key_ref));
+    }
+    Slice shorter_key_slice(shorter_key, sizeof(shorter_key) - 1);
+    key_refs[1] = std::cref(shorter_key_slice);
+
+    autovector<uint64_t> offsets{
+        blob_offsets[0],
+        blob_offsets[1] - (keys[1].size() - key_refs[1].get().size()),
+        blob_offsets[2]};
+    autovector<uint64_t> sizes{blob_sizes[0], blob_sizes[1], blob_sizes[2]};
+    std::array<Status, num_blobs> statuses_buf;
+    autovector<Status*> statuses{&statuses_buf[0], &statuses_buf[1],
+                                 &statuses_buf[2]};
+    std::array<PinnableSlice, num_blobs> value_buf;
+    autovector<PinnableSlice*> values{&value_buf[0], &value_buf[1],
+                                      &value_buf[2]};
+    reader->MultiGetBlob(read_options, key_refs, offsets, sizes, statuses,
+                         values, &bytes_read);
+    for (size_t i = 0; i < num_blobs; ++i) {
+      if (i == 1) {
+        ASSERT_TRUE(statuses_buf[i].IsCorruption());
+      } else {
+        ASSERT_OK(statuses_buf[i]);
+      }
+    }
  }

  // Incorrect key
  {
-    constexpr char incorrect_key[] = "foo";
+    constexpr char incorrect_key[] = "foo1";
    PinnableSlice value;
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
-                    ->GetBlob(read_options, incorrect_key, blob_offset,
-                              blob_size, kNoCompression, &value, &bytes_read)
+                    ->GetBlob(read_options, incorrect_key, blob_offsets[0],
+                              blob_sizes[0], kNoCompression, prefetch_buffer,
+                              &value, &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
+
+    // MultiGetBlob
+    autovector<std::reference_wrapper<const Slice>> key_refs;
+    for (const auto& key_ref : keys) {
+      key_refs.emplace_back(std::cref(key_ref));
+    }
+    Slice wrong_key_slice(incorrect_key, sizeof(incorrect_key) - 1);
+    key_refs[2] = std::cref(wrong_key_slice);
+
+    autovector<uint64_t> offsets{blob_offsets[0], blob_offsets[1],
+                                 blob_offsets[2]};
+    autovector<uint64_t> sizes{blob_sizes[0], blob_sizes[1], blob_sizes[2]};
+    std::array<Status, num_blobs> statuses_buf;
+    autovector<Status*> statuses{&statuses_buf[0], &statuses_buf[1],
+                                 &statuses_buf[2]};
+    std::array<PinnableSlice, num_blobs> value_buf;
+    autovector<PinnableSlice*> values{&value_buf[0], &value_buf[1],
+                                      &value_buf[2]};
+    reader->MultiGetBlob(read_options, key_refs, offsets, sizes, statuses,
+                         values, &bytes_read);
+    for (size_t i = 0; i < num_blobs; ++i) {
+      if (i == num_blobs - 1) {
+        ASSERT_TRUE(statuses_buf[i].IsCorruption());
+      } else {
+        ASSERT_OK(statuses_buf[i]);
+      }
+    }
  }

  // Incorrect value size
@@ -245,10 +365,35 @@ TEST_F(BlobFileReaderTest, CreateReaderAndGetBlob) {
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
-                    ->GetBlob(read_options, key, blob_offset, blob_size + 1,
-                              kNoCompression, &value, &bytes_read)
+                    ->GetBlob(read_options, keys[1], blob_offsets[1],
+                              blob_sizes[1] + 1, kNoCompression,
+                              prefetch_buffer, &value, &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
+
+    // MultiGetBlob
+    autovector<std::reference_wrapper<const Slice>> key_refs;
+    for (const auto& key_ref : keys) {
+      key_refs.emplace_back(std::cref(key_ref));
+    }
+    autovector<uint64_t> offsets{blob_offsets[0], blob_offsets[1],
+                                 blob_offsets[2]};
+    autovector<uint64_t> sizes{blob_sizes[0], blob_sizes[1] + 1, blob_sizes[2]};
+    std::array<Status, num_blobs> statuses_buf;
+    autovector<Status*> statuses{&statuses_buf[0], &statuses_buf[1],
+                                 &statuses_buf[2]};
+    std::array<PinnableSlice, num_blobs> value_buf;
+    autovector<PinnableSlice*> values{&value_buf[0], &value_buf[1],
+                                      &value_buf[2]};
+    reader->MultiGetBlob(read_options, key_refs, offsets, sizes, statuses,
+                         values, &bytes_read);
+    for (size_t i = 0; i < num_blobs; ++i) {
+      if (i != 1) {
+        ASSERT_OK(statuses_buf[i]);
+      } else {
+        ASSERT_TRUE(statuses_buf[i].IsCorruption());
+      }
+    }
  }
 }

@@ -257,12 +402,13 @@ TEST_F(BlobFileReaderTest, Malformed) {
  // detect the error when we open it for reading

  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileReaderTest_Malformed"), 0);
+      test::PerThreadDBPath(mock_env_.get(), "BlobFileReaderTest_Malformed"),
+      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr uint64_t blob_file_number = 1;
@@ -271,23 +417,23 @@ TEST_F(BlobFileReaderTest, Malformed) {
    constexpr bool has_ttl = false;
    constexpr ExpirationRange expiration_range;

-    const std::string blob_file_path = BlobFileName(
-        immutable_cf_options.cf_paths.front().path, blob_file_number);
+    const std::string blob_file_path =
+        BlobFileName(immutable_options.cf_paths.front().path, blob_file_number);

    std::unique_ptr<FSWritableFile> file;
-    ASSERT_OK(NewWritableFile(immutable_cf_options.fs, blob_file_path, &file,
+    ASSERT_OK(NewWritableFile(immutable_options.fs.get(), blob_file_path, &file,
                              FileOptions()));

    std::unique_ptr<WritableFileWriter> file_writer(
        new WritableFileWriter(std::move(file), blob_file_path, FileOptions(),
-                               immutable_cf_options.clock));
+                               immutable_options.clock));

    constexpr Statistics* statistics = nullptr;
    constexpr bool use_fsync = false;
    constexpr bool do_flush = false;

    BlobLogWriter blob_log_writer(std::move(file_writer),
-                                  immutable_cf_options.clock, statistics,
+                                  immutable_options.clock, statistics,
                                  blob_file_number, use_fsync, do_flush);

    BlobLogHeader header(column_family_id, kNoCompression, has_ttl,
@@ -300,7 +446,7 @@ TEST_F(BlobFileReaderTest, Malformed) {

  std::unique_ptr<BlobFileReader> reader;

-  ASSERT_TRUE(BlobFileReader::Create(immutable_cf_options, FileOptions(),
+  ASSERT_TRUE(BlobFileReader::Create(immutable_options, FileOptions(),
                                     column_family_id, blob_file_read_hist,
                                     blob_file_number, nullptr /*IOTracer*/,
                                     &reader)
@@ -309,12 +455,12 @@ TEST_F(BlobFileReaderTest, Malformed) {

 TEST_F(BlobFileReaderTest, TTL) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileReaderTest_TTL"), 0);
+      test::PerThreadDBPath(mock_env_.get(), "BlobFileReaderTest_TTL"), 0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = true;
@@ -326,15 +472,15 @@ TEST_F(BlobFileReaderTest, TTL) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
-                kNoCompression, &blob_offset, &blob_size);
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob, kNoCompression,
+                &blob_offset, &blob_size);

  constexpr HistogramImpl* blob_file_read_hist = nullptr;

  std::unique_ptr<BlobFileReader> reader;

-  ASSERT_TRUE(BlobFileReader::Create(immutable_cf_options, FileOptions(),
+  ASSERT_TRUE(BlobFileReader::Create(immutable_options, FileOptions(),
                                     column_family_id, blob_file_read_hist,
                                     blob_file_number, nullptr /*IOTracer*/,
                                     &reader)
@@ -343,14 +489,14 @@ TEST_F(BlobFileReaderTest, TTL) {

 TEST_F(BlobFileReaderTest, ExpirationRangeInHeader) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileReaderTest_ExpirationRangeInHeader"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -364,7 +510,7 @@ TEST_F(BlobFileReaderTest, ExpirationRangeInHeader) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
+  WriteBlobFile(immutable_options, column_family_id, has_ttl,
                expiration_range_header, expiration_range_footer,
                blob_file_number, key, blob, kNoCompression, &blob_offset,
                &blob_size);
@@ -373,7 +519,7 @@ TEST_F(BlobFileReaderTest, ExpirationRangeInHeader) {

  std::unique_ptr<BlobFileReader> reader;

-  ASSERT_TRUE(BlobFileReader::Create(immutable_cf_options, FileOptions(),
+  ASSERT_TRUE(BlobFileReader::Create(immutable_options, FileOptions(),
                                     column_family_id, blob_file_read_hist,
                                     blob_file_number, nullptr /*IOTracer*/,
                                     &reader)
@@ -382,14 +528,14 @@ TEST_F(BlobFileReaderTest, ExpirationRangeInHeader) {

 TEST_F(BlobFileReaderTest, ExpirationRangeInFooter) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileReaderTest_ExpirationRangeInFooter"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -403,7 +549,7 @@ TEST_F(BlobFileReaderTest, ExpirationRangeInFooter) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
+  WriteBlobFile(immutable_options, column_family_id, has_ttl,
                expiration_range_header, expiration_range_footer,
                blob_file_number, key, blob, kNoCompression, &blob_offset,
                &blob_size);
@@ -412,7 +558,7 @@ TEST_F(BlobFileReaderTest, ExpirationRangeInFooter) {

  std::unique_ptr<BlobFileReader> reader;

-  ASSERT_TRUE(BlobFileReader::Create(immutable_cf_options, FileOptions(),
+  ASSERT_TRUE(BlobFileReader::Create(immutable_options, FileOptions(),
                                     column_family_id, blob_file_read_hist,
                                     blob_file_number, nullptr /*IOTracer*/,
                                     &reader)
@@ -421,14 +567,14 @@ TEST_F(BlobFileReaderTest, ExpirationRangeInFooter) {

 TEST_F(BlobFileReaderTest, IncorrectColumnFamily) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileReaderTest_IncorrectColumnFamily"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -440,9 +586,9 @@ TEST_F(BlobFileReaderTest, IncorrectColumnFamily) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
-                kNoCompression, &blob_offset, &blob_size);
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob, kNoCompression,
+                &blob_offset, &blob_size);

  constexpr HistogramImpl* blob_file_read_hist = nullptr;

@@ -450,7 +596,7 @@ TEST_F(BlobFileReaderTest, IncorrectColumnFamily) {

  constexpr uint32_t incorrect_column_family_id = 2;

-  ASSERT_TRUE(BlobFileReader::Create(immutable_cf_options, FileOptions(),
+  ASSERT_TRUE(BlobFileReader::Create(immutable_options, FileOptions(),
                                     incorrect_column_family_id,
                                     blob_file_read_hist, blob_file_number,
                                     nullptr /*IOTracer*/, &reader)
@@ -459,12 +605,13 @@ TEST_F(BlobFileReaderTest, IncorrectColumnFamily) {

 TEST_F(BlobFileReaderTest, BlobCRCError) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileReaderTest_BlobCRCError"), 0);
+      test::PerThreadDBPath(mock_env_.get(), "BlobFileReaderTest_BlobCRCError"),
+      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -476,17 +623,17 @@ TEST_F(BlobFileReaderTest, BlobCRCError) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
-                kNoCompression, &blob_offset, &blob_size);
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob, kNoCompression,
+                &blob_offset, &blob_size);

  constexpr HistogramImpl* blob_file_read_hist = nullptr;

  std::unique_ptr<BlobFileReader> reader;

  ASSERT_OK(BlobFileReader::Create(
-      immutable_cf_options, FileOptions(), column_family_id,
-      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader));
+      immutable_options, FileOptions(), column_family_id, blob_file_read_hist,
+      blob_file_number, nullptr /*IOTracer*/, &reader));

  SyncPoint::GetInstance()->SetCallBack(
      "BlobFileReader::VerifyBlob:CheckBlobCRC", [](void* arg) {
@@ -498,12 +645,14 @@ TEST_F(BlobFileReaderTest, BlobCRCError) {

  SyncPoint::GetInstance()->EnableProcessing();

+  constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
  PinnableSlice value;
  uint64_t bytes_read = 0;

  ASSERT_TRUE(reader
                  ->GetBlob(ReadOptions(), key, blob_offset, blob_size,
-                            kNoCompression, &value, &bytes_read)
+                            kNoCompression, prefetch_buffer, &value,
+                            &bytes_read)
                  .IsCorruption());
  ASSERT_EQ(bytes_read, 0);

@@ -517,12 +666,13 @@ TEST_F(BlobFileReaderTest, Compression) {
  }

  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_, "BlobFileReaderTest_Compression"), 0);
+      test::PerThreadDBPath(mock_env_.get(), "BlobFileReaderTest_Compression"),
+      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -534,8 +684,8 @@ TEST_F(BlobFileReaderTest, Compression) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob,
                kSnappyCompression, &blob_offset, &blob_size);

  constexpr HistogramImpl* blob_file_read_hist = nullptr;
@@ -543,19 +693,22 @@ TEST_F(BlobFileReaderTest, Compression) {
  std::unique_ptr<BlobFileReader> reader;

  ASSERT_OK(BlobFileReader::Create(
-      immutable_cf_options, FileOptions(), column_family_id,
-      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader));
+      immutable_options, FileOptions(), column_family_id, blob_file_read_hist,
+      blob_file_number, nullptr /*IOTracer*/, &reader));

  // Make sure the blob can be retrieved with and without checksum verification
  ReadOptions read_options;
  read_options.verify_checksums = false;

+  constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
+
  {
    PinnableSlice value;
    uint64_t bytes_read = 0;

    ASSERT_OK(reader->GetBlob(read_options, key, blob_offset, blob_size,
-                              kSnappyCompression, &value, &bytes_read));
+                              kSnappyCompression, prefetch_buffer, &value,
+                              &bytes_read));
    ASSERT_EQ(value, blob);
    ASSERT_EQ(bytes_read, blob_size);
  }
@@ -567,7 +720,8 @@ TEST_F(BlobFileReaderTest, Compression) {
    uint64_t bytes_read = 0;

    ASSERT_OK(reader->GetBlob(read_options, key, blob_offset, blob_size,
-                              kSnappyCompression, &value, &bytes_read));
+                              kSnappyCompression, prefetch_buffer, &value,
+                              &bytes_read));
    ASSERT_EQ(value, blob);

    constexpr uint64_t key_size = sizeof(key) - 1;
@@ -583,14 +737,14 @@ TEST_F(BlobFileReaderTest, UncompressionError) {
  }

  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileReaderTest_UncompressionError"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -602,8 +756,8 @@ TEST_F(BlobFileReaderTest, UncompressionError) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob,
                kSnappyCompression, &blob_offset, &blob_size);

  constexpr HistogramImpl* blob_file_read_hist = nullptr;
@@ -611,8 +765,8 @@ TEST_F(BlobFileReaderTest, UncompressionError) {
  std::unique_ptr<BlobFileReader> reader;

  ASSERT_OK(BlobFileReader::Create(
-      immutable_cf_options, FileOptions(), column_family_id,
-      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader));
+      immutable_options, FileOptions(), column_family_id, blob_file_read_hist,
+      blob_file_number, nullptr /*IOTracer*/, &reader));

  SyncPoint::GetInstance()->SetCallBack(
      "BlobFileReader::UncompressBlobIfNeeded:TamperWithResult", [](void* arg) {
@@ -625,12 +779,14 @@ TEST_F(BlobFileReaderTest, UncompressionError) {

  SyncPoint::GetInstance()->EnableProcessing();

+  constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
  PinnableSlice value;
  uint64_t bytes_read = 0;

  ASSERT_TRUE(reader
                  ->GetBlob(ReadOptions(), key, blob_offset, blob_size,
-                            kSnappyCompression, &value, &bytes_read)
+                            kSnappyCompression, prefetch_buffer, &value,
+                            &bytes_read)
                  .IsCorruption());
  ASSERT_EQ(bytes_read, 0);

@@ -642,13 +798,13 @@ class BlobFileReaderIOErrorTest
    : public testing::Test,
      public testing::WithParamInterface<std::string> {
 protected:
-  BlobFileReaderIOErrorTest()
-      : mock_env_(Env::Default()),
-        fault_injection_env_(&mock_env_),
-        sync_point_(GetParam()) {}
+  BlobFileReaderIOErrorTest() : sync_point_(GetParam()) {
+    mock_env_.reset(MockEnv::Create(Env::Default()));
+    fault_injection_env_.reset(new FaultInjectionTestEnv(mock_env_.get()));
+  }

-  MockEnv mock_env_;
-  FaultInjectionTestEnv fault_injection_env_;
+  std::unique_ptr<Env> mock_env_;
+  std::unique_ptr<FaultInjectionTestEnv> fault_injection_env_;
  std::string sync_point_;
 };

@@ -664,14 +820,14 @@ TEST_P(BlobFileReaderIOErrorTest, IOError) {
  // Simulates an I/O error during the specified step

  Options options;
-  options.env = &fault_injection_env_;
+  options.env = fault_injection_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&fault_injection_env_,
+      test::PerThreadDBPath(fault_injection_env_.get(),
                            "BlobFileReaderIOErrorTest_IOError"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -683,13 +839,13 @@ TEST_P(BlobFileReaderIOErrorTest, IOError) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
-                kNoCompression, &blob_offset, &blob_size);
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob, kNoCompression,
+                &blob_offset, &blob_size);

  SyncPoint::GetInstance()->SetCallBack(sync_point_, [this](void* /* arg */) {
-    fault_injection_env_.SetFilesystemActive(false,
-                                             Status::IOError(sync_point_));
+    fault_injection_env_->SetFilesystemActive(false,
+                                              Status::IOError(sync_point_));
  });
  SyncPoint::GetInstance()->EnableProcessing();

@@ -698,8 +854,8 @@ TEST_P(BlobFileReaderIOErrorTest, IOError) {
  std::unique_ptr<BlobFileReader> reader;

  const Status s = BlobFileReader::Create(
-      immutable_cf_options, FileOptions(), column_family_id,
-      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader);
+      immutable_options, FileOptions(), column_family_id, blob_file_read_hist,
+      blob_file_number, nullptr /*IOTracer*/, &reader);

  const bool fail_during_create =
      (sync_point_ != "BlobFileReader::GetBlob:ReadFromFile");
@@ -709,12 +865,14 @@ TEST_P(BlobFileReaderIOErrorTest, IOError) {
  } else {
    ASSERT_OK(s);

+    constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
    PinnableSlice value;
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
                    ->GetBlob(ReadOptions(), key, blob_offset, blob_size,
-                              kNoCompression, &value, &bytes_read)
+                              kNoCompression, prefetch_buffer, &value,
+                              &bytes_read)
                    .IsIOError());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -727,10 +885,11 @@ class BlobFileReaderDecodingErrorTest
    : public testing::Test,
      public testing::WithParamInterface<std::string> {
 protected:
-  BlobFileReaderDecodingErrorTest()
-      : mock_env_(Env::Default()), sync_point_(GetParam()) {}
+  BlobFileReaderDecodingErrorTest() : sync_point_(GetParam()) {
+    mock_env_.reset(MockEnv::Create(Env::Default()));
+  }

-  MockEnv mock_env_;
+  std::unique_ptr<Env> mock_env_;
  std::string sync_point_;
 };

@@ -742,14 +901,14 @@ INSTANTIATE_TEST_CASE_P(BlobFileReaderTest, BlobFileReaderDecodingErrorTest,

 TEST_P(BlobFileReaderDecodingErrorTest, DecodingError) {
  Options options;
-  options.env = &mock_env_;
+  options.env = mock_env_.get();
  options.cf_paths.emplace_back(
-      test::PerThreadDBPath(&mock_env_,
+      test::PerThreadDBPath(mock_env_.get(),
                            "BlobFileReaderDecodingErrorTest_DecodingError"),
      0);
  options.enable_blob_files = true;

-  ImmutableCFOptions immutable_cf_options(options);
+  ImmutableOptions immutable_options(options);

  constexpr uint32_t column_family_id = 1;
  constexpr bool has_ttl = false;
@@ -761,9 +920,9 @@ TEST_P(BlobFileReaderDecodingErrorTest, DecodingError) {
  uint64_t blob_offset = 0;
  uint64_t blob_size = 0;

-  WriteBlobFile(immutable_cf_options, column_family_id, has_ttl,
-                expiration_range, expiration_range, blob_file_number, key, blob,
-                kNoCompression, &blob_offset, &blob_size);
+  WriteBlobFile(immutable_options, column_family_id, has_ttl, expiration_range,
+                expiration_range, blob_file_number, key, blob, kNoCompression,
+                &blob_offset, &blob_size);

  SyncPoint::GetInstance()->SetCallBack(sync_point_, [](void* arg) {
    Slice* const slice = static_cast<Slice*>(arg);
@@ -780,8 +939,8 @@ TEST_P(BlobFileReaderDecodingErrorTest, DecodingError) {
  std::unique_ptr<BlobFileReader> reader;

  const Status s = BlobFileReader::Create(
-      immutable_cf_options, FileOptions(), column_family_id,
-      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader);
+      immutable_options, FileOptions(), column_family_id, blob_file_read_hist,
+      blob_file_number, nullptr /*IOTracer*/, &reader);

  const bool fail_during_create =
      sync_point_ != "BlobFileReader::GetBlob:TamperWithResult";
@@ -791,12 +950,14 @@ TEST_P(BlobFileReaderDecodingErrorTest, DecodingError) {
  } else {
    ASSERT_OK(s);

+    constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
    PinnableSlice value;
    uint64_t bytes_read = 0;

    ASSERT_TRUE(reader
                    ->GetBlob(ReadOptions(), key, blob_offset, blob_size,
-                              kNoCompression, &value, &bytes_read)
+                              kNoCompression, prefetch_buffer, &value,
+                              &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -0,0 +1,100 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/blob_garbage_meter.h"
+
+#include "db/blob/blob_index.h"
+#include "db/blob/blob_log_format.h"
+#include "db/dbformat.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+Status BlobGarbageMeter::ProcessInFlow(const Slice& key, const Slice& value) {
+  uint64_t blob_file_number = kInvalidBlobFileNumber;
+  uint64_t bytes = 0;
+
+  const Status s = Parse(key, value, &blob_file_number, &bytes);
+  if (!s.ok()) {
+    return s;
+  }
+
+  if (blob_file_number == kInvalidBlobFileNumber) {
+    return Status::OK();
+  }
+
+  flows_[blob_file_number].AddInFlow(bytes);
+
+  return Status::OK();
+}
+
+Status BlobGarbageMeter::ProcessOutFlow(const Slice& key, const Slice& value) {
+  uint64_t blob_file_number = kInvalidBlobFileNumber;
+  uint64_t bytes = 0;
+
+  const Status s = Parse(key, value, &blob_file_number, &bytes);
+  if (!s.ok()) {
+    return s;
+  }
+
+  if (blob_file_number == kInvalidBlobFileNumber) {
+    return Status::OK();
+  }
+
+  // Note: in order to measure the amount of additional garbage, we only need to
+  // track the outflow for preexisting files, i.e. those that also had inflow.
+  // (Newly written files would only have outflow.)
+  auto it = flows_.find(blob_file_number);
+  if (it == flows_.end()) {
+    return Status::OK();
+  }
+
+  it->second.AddOutFlow(bytes);
+
+  return Status::OK();
+}
+
+Status BlobGarbageMeter::Parse(const Slice& key, const Slice& value,
+                               uint64_t* blob_file_number, uint64_t* bytes) {
+  assert(blob_file_number);
+  assert(*blob_file_number == kInvalidBlobFileNumber);
+  assert(bytes);
+  assert(*bytes == 0);
+
+  ParsedInternalKey ikey;
+
+  {
+    constexpr bool log_err_key = false;
+    const Status s = ParseInternalKey(key, &ikey, log_err_key);
+    if (!s.ok()) {
+      return s;
+    }
+  }
+
+  if (ikey.type != kTypeBlobIndex) {
+    return Status::OK();
+  }
+
+  BlobIndex blob_index;
+
+  {
+    const Status s = blob_index.DecodeFrom(value);
+    if (!s.ok()) {
+      return s;
+    }
+  }
+
+  if (blob_index.IsInlined() || blob_index.HasTTL()) {
+    return Status::Corruption("Unexpected TTL/inlined blob index");
+  }
+
+  *blob_file_number = blob_index.file_number();
+  *bytes =
+      blob_index.size() +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(ikey.user_key.size());
+
+  return Status::OK();
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,102 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <cassert>
+#include <cstdint>
+#include <unordered_map>
+
+#include "db/blob/blob_constants.h"
+#include "rocksdb/rocksdb_namespace.h"
+#include "rocksdb/status.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Slice;
+
+// A class that can be used to compute the amount of additional garbage
+// generated by a compaction. It parses the keys and blob references in the
+// input and output of a compaction, and aggregates the "inflow" and "outflow"
+// on a per-blob file basis. The amount of additional garbage for any given blob
+// file can then be computed by subtracting the outflow from the inflow.
+class BlobGarbageMeter {
+ public:
+  // A class to store the number and total size of blobs on a per-blob file
+  // basis.
+  class BlobStats {
+   public:
+    void Add(uint64_t bytes) {
+      ++count_;
+      bytes_ += bytes;
+    }
+    void Add(uint64_t count, uint64_t bytes) {
+      count_ += count;
+      bytes_ += bytes;
+    }
+
+    uint64_t GetCount() const { return count_; }
+    uint64_t GetBytes() const { return bytes_; }
+
+   private:
+    uint64_t count_ = 0;
+    uint64_t bytes_ = 0;
+  };
+
+  // A class to keep track of the "inflow" and the "outflow" and to compute the
+  // amount of additional garbage for a given blob file.
+  class BlobInOutFlow {
+   public:
+    void AddInFlow(uint64_t bytes) {
+      in_flow_.Add(bytes);
+      assert(IsValid());
+    }
+    void AddOutFlow(uint64_t bytes) {
+      out_flow_.Add(bytes);
+      assert(IsValid());
+    }
+
+    const BlobStats& GetInFlow() const { return in_flow_; }
+    const BlobStats& GetOutFlow() const { return out_flow_; }
+
+    bool IsValid() const {
+      return in_flow_.GetCount() >= out_flow_.GetCount() &&
+             in_flow_.GetBytes() >= out_flow_.GetBytes();
+    }
+    bool HasGarbage() const {
+      assert(IsValid());
+      return in_flow_.GetCount() > out_flow_.GetCount();
+    }
+    uint64_t GetGarbageCount() const {
+      assert(IsValid());
+      assert(HasGarbage());
+      return in_flow_.GetCount() - out_flow_.GetCount();
+    }
+    uint64_t GetGarbageBytes() const {
+      assert(IsValid());
+      assert(HasGarbage());
+      return in_flow_.GetBytes() - out_flow_.GetBytes();
+    }
+
+   private:
+    BlobStats in_flow_;
+    BlobStats out_flow_;
+  };
+
+  Status ProcessInFlow(const Slice& key, const Slice& value);
+  Status ProcessOutFlow(const Slice& key, const Slice& value);
+
+  const std::unordered_map<uint64_t, BlobInOutFlow>& flows() const {
+    return flows_;
+  }
+
+ private:
+  static Status Parse(const Slice& key, const Slice& value,
+                      uint64_t* blob_file_number, uint64_t* bytes);
+
+  std::unordered_map<uint64_t, BlobInOutFlow> flows_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,196 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/blob_garbage_meter.h"
+
+#include <string>
+#include <vector>
+
+#include "db/blob/blob_index.h"
+#include "db/blob/blob_log_format.h"
+#include "db/dbformat.h"
+#include "test_util/testharness.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+TEST(BlobGarbageMeterTest, MeasureGarbage) {
+  BlobGarbageMeter blob_garbage_meter;
+
+  struct BlobDescriptor {
+    std::string user_key;
+    uint64_t blob_file_number;
+    uint64_t offset;
+    uint64_t size;
+    CompressionType compression_type;
+    bool has_in_flow;
+    bool has_out_flow;
+
+    uint64_t GetExpectedBytes() const {
+      return size +
+             BlobLogRecord::CalculateAdjustmentForRecordHeader(user_key.size());
+    }
+  };
+
+  // Note: blob file 4 has the same inflow and outflow and hence no additional
+  // garbage. Blob file 5 has less outflow than inflow and thus it does have
+  // additional garbage. Blob file 6 is a newly written file (i.e. no inflow,
+  // only outflow) and is thus not tracked by the meter.
+  std::vector<BlobDescriptor> blobs{
+      {"key", 4, 1234, 555, kLZ4Compression, true, true},
+      {"other_key", 4, 6789, 101010, kLZ4Compression, true, true},
+      {"yet_another_key", 5, 22222, 3456, kLZ4Compression, true, true},
+      {"foo_key", 5, 77777, 8888, kLZ4Compression, true, true},
+      {"bar_key", 5, 999999, 1212, kLZ4Compression, true, false},
+      {"baz_key", 5, 1234567, 890, kLZ4Compression, true, false},
+      {"new_key", 6, 7777, 9999, kNoCompression, false, true}};
+
+  for (const auto& blob : blobs) {
+    constexpr SequenceNumber seq = 123;
+    const InternalKey key(blob.user_key, seq, kTypeBlobIndex);
+    const Slice key_slice = key.Encode();
+
+    std::string value;
+    BlobIndex::EncodeBlob(&value, blob.blob_file_number, blob.offset, blob.size,
+                          blob.compression_type);
+    const Slice value_slice(value);
+
+    if (blob.has_in_flow) {
+      ASSERT_OK(blob_garbage_meter.ProcessInFlow(key_slice, value_slice));
+    }
+    if (blob.has_out_flow) {
+      ASSERT_OK(blob_garbage_meter.ProcessOutFlow(key_slice, value_slice));
+    }
+  }
+
+  const auto& flows = blob_garbage_meter.flows();
+  ASSERT_EQ(flows.size(), 2);
+
+  {
+    const auto it = flows.find(4);
+    ASSERT_NE(it, flows.end());
+
+    const auto& flow = it->second;
+
+    constexpr uint64_t expected_count = 2;
+    const uint64_t expected_bytes =
+        blobs[0].GetExpectedBytes() + blobs[1].GetExpectedBytes();
+
+    const auto& in = flow.GetInFlow();
+    ASSERT_EQ(in.GetCount(), expected_count);
+    ASSERT_EQ(in.GetBytes(), expected_bytes);
+
+    const auto& out = flow.GetOutFlow();
+    ASSERT_EQ(out.GetCount(), expected_count);
+    ASSERT_EQ(out.GetBytes(), expected_bytes);
+
+    ASSERT_TRUE(flow.IsValid());
+    ASSERT_FALSE(flow.HasGarbage());
+  }
+
+  {
+    const auto it = flows.find(5);
+    ASSERT_NE(it, flows.end());
+
+    const auto& flow = it->second;
+
+    const auto& in = flow.GetInFlow();
+
+    constexpr uint64_t expected_in_count = 4;
+    const uint64_t expected_in_bytes =
+        blobs[2].GetExpectedBytes() + blobs[3].GetExpectedBytes() +
+        blobs[4].GetExpectedBytes() + blobs[5].GetExpectedBytes();
+
+    ASSERT_EQ(in.GetCount(), expected_in_count);
+    ASSERT_EQ(in.GetBytes(), expected_in_bytes);
+
+    const auto& out = flow.GetOutFlow();
+
+    constexpr uint64_t expected_out_count = 2;
+    const uint64_t expected_out_bytes =
+        blobs[2].GetExpectedBytes() + blobs[3].GetExpectedBytes();
+
+    ASSERT_EQ(out.GetCount(), expected_out_count);
+    ASSERT_EQ(out.GetBytes(), expected_out_bytes);
+
+    ASSERT_TRUE(flow.IsValid());
+    ASSERT_TRUE(flow.HasGarbage());
+    ASSERT_EQ(flow.GetGarbageCount(), expected_in_count - expected_out_count);
+    ASSERT_EQ(flow.GetGarbageBytes(), expected_in_bytes - expected_out_bytes);
+  }
+}
+
+TEST(BlobGarbageMeterTest, PlainValue) {
+  constexpr char user_key[] = "user_key";
+  constexpr SequenceNumber seq = 123;
+
+  const InternalKey key(user_key, seq, kTypeValue);
+  const Slice key_slice = key.Encode();
+
+  constexpr char value[] = "value";
+  const Slice value_slice(value);
+
+  BlobGarbageMeter blob_garbage_meter;
+
+  ASSERT_OK(blob_garbage_meter.ProcessInFlow(key_slice, value_slice));
+  ASSERT_OK(blob_garbage_meter.ProcessOutFlow(key_slice, value_slice));
+  ASSERT_TRUE(blob_garbage_meter.flows().empty());
+}
+
+TEST(BlobGarbageMeterTest, CorruptInternalKey) {
+  constexpr char corrupt_key[] = "i_am_corrupt";
+  const Slice key_slice(corrupt_key);
+
+  constexpr char value[] = "value";
+  const Slice value_slice(value);
+
+  BlobGarbageMeter blob_garbage_meter;
+
+  ASSERT_NOK(blob_garbage_meter.ProcessInFlow(key_slice, value_slice));
+  ASSERT_NOK(blob_garbage_meter.ProcessOutFlow(key_slice, value_slice));
+}
+
+TEST(BlobGarbageMeterTest, CorruptBlobIndex) {
+  constexpr char user_key[] = "user_key";
+  constexpr SequenceNumber seq = 123;
+
+  const InternalKey key(user_key, seq, kTypeBlobIndex);
+  const Slice key_slice = key.Encode();
+
+  constexpr char value[] = "i_am_not_a_blob_index";
+  const Slice value_slice(value);
+
+  BlobGarbageMeter blob_garbage_meter;
+
+  ASSERT_NOK(blob_garbage_meter.ProcessInFlow(key_slice, value_slice));
+  ASSERT_NOK(blob_garbage_meter.ProcessOutFlow(key_slice, value_slice));
+}
+
+TEST(BlobGarbageMeterTest, InlinedTTLBlobIndex) {
+  constexpr char user_key[] = "user_key";
+  constexpr SequenceNumber seq = 123;
+
+  const InternalKey key(user_key, seq, kTypeBlobIndex);
+  const Slice key_slice = key.Encode();
+
+  constexpr uint64_t expiration = 1234567890;
+  constexpr char inlined_value[] = "inlined";
+
+  std::string value;
+  BlobIndex::EncodeInlinedTTL(&value, expiration, inlined_value);
+
+  const Slice value_slice(value);
+
+  BlobGarbageMeter blob_garbage_meter;
+
+  ASSERT_NOK(blob_garbage_meter.ProcessInFlow(key_slice, value_slice));
+  ASSERT_NOK(blob_garbage_meter.ProcessOutFlow(key_slice, value_slice));
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -52,6 +52,9 @@ class BlobIndex {

  BlobIndex() : type_(Type::kUnknown) {}

+  BlobIndex(const BlobIndex&) = default;
+  BlobIndex& operator=(const BlobIndex&) = default;
+
  bool IsInlined() const { return type_ == Type::kInlinedTTL; }

  bool HasTTL() const {
@@ -107,7 +107,8 @@ struct BlobLogRecord {
  // Note that the offset field of BlobIndex actually points to the blob value
  // as opposed to the start of the blob record. The following method can
  // be used to calculate the adjustment needed to read the blob record header.
-  static uint64_t CalculateAdjustmentForRecordHeader(uint64_t key_size) {
+  static constexpr uint64_t CalculateAdjustmentForRecordHeader(
+      uint64_t key_size) {
    return key_size + kHeaderSize;
  }

@@ -28,8 +28,10 @@ Status BlobLogSequentialReader::ReadSlice(uint64_t size, Slice* slice,
  assert(file_);

  StopWatch read_sw(clock_, statistics_, BLOB_DB_BLOB_FILE_READ_MICROS);
-  Status s = file_->Read(IOOptions(), next_byte_, static_cast<size_t>(size),
-                         slice, buf, nullptr);
+  // TODO: rate limit `BlobLogSequentialReader` reads (it appears unused?)
+  Status s =
+      file_->Read(IOOptions(), next_byte_, static_cast<size_t>(size), slice,
+                  buf, nullptr, Env::IO_TOTAL /* rate_limiter_priority */);
  next_byte_ += size;
  if (!s.ok()) {
    return s;
@@ -10,6 +10,8 @@
 #include "db/blob/blob_log_format.h"
 #include "rocksdb/slice.h"

+#define MAX_HEADER_SIZE(a, b, c) (a > b ? (a > c ? a : c) : (b > c ? b : c))
+
 namespace ROCKSDB_NAMESPACE {

 class RandomAccessFileReader;
@@ -69,10 +71,13 @@ class BlobLogSequentialReader {
  Statistics* statistics_;

  Slice buffer_;
-  char header_buf_[BlobLogRecord::kHeaderSize];
+  char header_buf_[MAX_HEADER_SIZE(BlobLogHeader::kSize, BlobLogFooter::kSize,
+                                   BlobLogRecord::kHeaderSize)];

  // which byte to read next
  uint64_t next_byte_;
 };

 }  // namespace ROCKSDB_NAMESPACE
+
+#undef MAX_HEADER_SIZE
@@ -4,8 +4,10 @@
 //  (found in the LICENSE.Apache file in the root directory).

 #include <array>
+#include <sstream>

 #include "db/blob/blob_index.h"
+#include "db/blob/blob_log_format.h"
 #include "db/db_test_util.h"
 #include "port/stack_trace.h"
 #include "test_util/sync_point.h"
@@ -16,7 +18,7 @@ namespace ROCKSDB_NAMESPACE {
 class DBBlobBasicTest : public DBTestBase {
 protected:
  DBBlobBasicTest()
-      : DBTestBase("/db_blob_basic_test", /* env_do_fsync */ false) {}
+      : DBTestBase("db_blob_basic_test", /* env_do_fsync */ false) {}
 };

 TEST_F(DBBlobBasicTest, GetBlob) {
@@ -125,6 +127,237 @@ TEST_F(DBBlobBasicTest, MultiGetBlobs) {
  }
 }

+#ifndef ROCKSDB_LITE
+TEST_F(DBBlobBasicTest, MultiGetWithDirectIO) {
+  Options options = GetDefaultOptions();
+
+  // First, create an external SST file ["b"].
+  const std::string file_path = dbname_ + "/test.sst";
+  {
+    SstFileWriter sst_file_writer(EnvOptions(), GetDefaultOptions());
+    Status s = sst_file_writer.Open(file_path);
+    ASSERT_OK(s);
+    ASSERT_OK(sst_file_writer.Put("b", "b_value"));
+    ASSERT_OK(sst_file_writer.Finish());
+  }
+
+  options.enable_blob_files = true;
+  options.min_blob_size = 1000;
+  options.use_direct_reads = true;
+  options.allow_ingest_behind = true;
+
+  // Open DB with fixed-prefix sst-partitioner so that compaction will cut
+  // new table file when encountering a new key whose 1-byte prefix changes.
+  constexpr size_t key_len = 1;
+  options.sst_partitioner_factory =
+      NewSstPartitionerFixedPrefixFactory(key_len);
+
+  Status s = TryReopen(options);
+  if (s.IsInvalidArgument()) {
+    ROCKSDB_GTEST_SKIP("This test requires direct IO support");
+    return;
+  }
+  ASSERT_OK(s);
+
+  constexpr size_t num_keys = 3;
+  constexpr size_t blob_size = 3000;
+
+  constexpr char first_key[] = "a";
+  const std::string first_blob(blob_size, 'a');
+  ASSERT_OK(Put(first_key, first_blob));
+
+  constexpr char second_key[] = "b";
+  const std::string second_blob(2 * blob_size, 'b');
+  ASSERT_OK(Put(second_key, second_blob));
+
+  constexpr char third_key[] = "d";
+  const std::string third_blob(blob_size, 'd');
+  ASSERT_OK(Put(third_key, third_blob));
+
+  // first_blob, second_blob and third_blob in the same blob file.
+  //      SST                    Blob file
+  // L0  ["a",    "b",    "d"]   |'aaaa', 'bbbb', 'dddd'|
+  //       |       |       |         ^       ^        ^
+  //       |       |       |         |       |        |
+  //       |       |       +---------|-------|--------+
+  //       |       +-----------------|-------+
+  //       +-------------------------+
+  ASSERT_OK(Flush());
+
+  constexpr char fourth_key[] = "c";
+  const std::string fourth_blob(blob_size, 'c');
+  ASSERT_OK(Put(fourth_key, fourth_blob));
+  // fourth_blob in another blob file.
+  //      SST                    Blob file                 SST     Blob file
+  // L0  ["a",    "b",    "d"]   |'aaaa', 'bbbb', 'dddd'|  ["c"]   |'cccc'|
+  //       |       |       |         ^       ^        ^      |       ^
+  //       |       |       |         |       |        |      |       |
+  //       |       |       +---------|-------|--------+      +-------+
+  //       |       +-----------------|-------+
+  //       +-------------------------+
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), /*begin=*/nullptr,
+                              /*end=*/nullptr));
+
+  // Due to the above sst partitioner, we get 4 L1 files. The blob files are
+  // unchanged.
+  //                             |'aaaa', 'bbbb', 'dddd'|  |'cccc'|
+  //                                 ^       ^     ^         ^
+  //                                 |       |     |         |
+  // L0                              |       |     |         |
+  // L1  ["a"]   ["b"]   ["c"]       |       |   ["d"]       |
+  //       |       |       |         |       |               |
+  //       |       |       +---------|-------|---------------+
+  //       |       +-----------------|-------+
+  //       +-------------------------+
+  ASSERT_EQ(4, NumTableFilesAtLevel(/*level=*/1));
+
+  {
+    // Ingest the external SST file into bottommost level.
+    std::vector<std::string> ext_files{file_path};
+    IngestExternalFileOptions opts;
+    opts.ingest_behind = true;
+    ASSERT_OK(
+        db_->IngestExternalFile(db_->DefaultColumnFamily(), ext_files, opts));
+  }
+
+  // Now the database becomes as follows.
+  //                             |'aaaa', 'bbbb', 'dddd'|  |'cccc'|
+  //                                 ^       ^     ^         ^
+  //                                 |       |     |         |
+  // L0                              |       |     |         |
+  // L1  ["a"]   ["b"]   ["c"]       |       |   ["d"]       |
+  //       |       |       |         |       |               |
+  //       |       |       +---------|-------|---------------+
+  //       |       +-----------------|-------+
+  //       +-------------------------+
+  //
+  // L6          ["b"]
+
+  {
+    // Compact ["b"] to bottommost level.
+    Slice begin = Slice(second_key);
+    Slice end = Slice(second_key);
+    CompactRangeOptions cro;
+    cro.bottommost_level_compaction = BottommostLevelCompaction::kForce;
+    ASSERT_OK(db_->CompactRange(cro, &begin, &end));
+  }
+
+  //                             |'aaaa', 'bbbb', 'dddd'|  |'cccc'|
+  //                                 ^       ^     ^         ^
+  //                                 |       |     |         |
+  // L0                              |       |     |         |
+  // L1  ["a"]           ["c"]       |       |   ["d"]       |
+  //       |               |         |       |               |
+  //       |               +---------|-------|---------------+
+  //       |       +-----------------|-------+
+  //       +-------|-----------------+
+  //               |
+  // L6          ["b"]
+  ASSERT_EQ(3, NumTableFilesAtLevel(/*level=*/1));
+  ASSERT_EQ(1, NumTableFilesAtLevel(/*level=*/6));
+
+  bool called = false;
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "RandomAccessFileReader::MultiRead:AlignedReqs", [&](void* arg) {
+        auto* aligned_reqs = static_cast<std::vector<FSReadRequest>*>(arg);
+        assert(aligned_reqs);
+        ASSERT_EQ(1, aligned_reqs->size());
+        called = true;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  std::array<Slice, num_keys> keys{{first_key, third_key, second_key}};
+
+  {
+    std::array<PinnableSlice, num_keys> values;
+    std::array<Status, num_keys> statuses;
+
+    // The MultiGet(), when constructing the KeyContexts, will process the keys
+    // in such order: a, d, b. The reason is that ["a"] and ["d"] are in L1,
+    // while ["b"] resides in L6.
+    // Consequently, the original FSReadRequest list prepared by
+    // Version::MultiGetblob() will be for "a", "d" and "b". It is unsorted as
+    // follows:
+    //
+    // ["a", offset=30, len=3033],
+    // ["d", offset=9096, len=3033],
+    // ["b", offset=3063, len=6033]
+    //
+    // If we do not sort them before calling MultiRead() in DirectIO, then the
+    // underlying IO merging logic will yield two requests.
+    //
+    // [offset=0, len=4096] (for "a")
+    // [offset=0, len=12288] (result of merging the request for "d" and "b")
+    //
+    // We need to sort them in Version::MultiGetBlob() so that the underlying
+    // IO merging logic in DirectIO mode works as expected. The correct
+    // behavior will be one aligned request:
+    //
+    // [offset=0, len=12288]
+
+    db_->MultiGet(ReadOptions(), db_->DefaultColumnFamily(), num_keys, &keys[0],
+                  &values[0], &statuses[0]);
+
+    SyncPoint::GetInstance()->DisableProcessing();
+    SyncPoint::GetInstance()->ClearAllCallBacks();
+
+    ASSERT_TRUE(called);
+
+    ASSERT_OK(statuses[0]);
+    ASSERT_EQ(values[0], first_blob);
+
+    ASSERT_OK(statuses[1]);
+    ASSERT_EQ(values[1], third_blob);
+
+    ASSERT_OK(statuses[2]);
+    ASSERT_EQ(values[2], second_blob);
+  }
+}
+#endif  // !ROCKSDB_LITE
+
+TEST_F(DBBlobBasicTest, MultiGetBlobsFromMultipleFiles) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  constexpr size_t kNumBlobFiles = 3;
+  constexpr size_t kNumBlobsPerFile = 3;
+  constexpr size_t kNumKeys = kNumBlobsPerFile * kNumBlobFiles;
+
+  std::vector<std::string> key_strs;
+  std::vector<std::string> value_strs;
+  for (size_t i = 0; i < kNumBlobFiles; ++i) {
+    for (size_t j = 0; j < kNumBlobsPerFile; ++j) {
+      std::string key = "key" + std::to_string(i) + "_" + std::to_string(j);
+      std::string value =
+          "value_as_blob" + std::to_string(i) + "_" + std::to_string(j);
+      ASSERT_OK(Put(key, value));
+      key_strs.push_back(key);
+      value_strs.push_back(value);
+    }
+    ASSERT_OK(Flush());
+  }
+  assert(key_strs.size() == kNumKeys);
+  std::array<Slice, kNumKeys> keys;
+  for (size_t i = 0; i < keys.size(); ++i) {
+    keys[i] = key_strs[i];
+  }
+  std::array<PinnableSlice, kNumKeys> values;
+  std::array<Status, kNumKeys> statuses;
+  db_->MultiGet(ReadOptions(), db_->DefaultColumnFamily(), kNumKeys, &keys[0],
+                &values[0], &statuses[0]);
+
+  for (size_t i = 0; i < kNumKeys; ++i) {
+    ASSERT_OK(statuses[i]);
+    ASSERT_EQ(value_strs[i], values[i]);
+  }
+}
+
 TEST_F(DBBlobBasicTest, GetBlob_CorruptIndex) {
  Options options = GetDefaultOptions();
  options.enable_blob_files = true;
@@ -148,6 +381,83 @@ TEST_F(DBBlobBasicTest, GetBlob_CorruptIndex) {
                  .IsCorruption());
 }

+TEST_F(DBBlobBasicTest, MultiGetBlob_CorruptIndex) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+  options.create_if_missing = true;
+
+  DestroyAndReopen(options);
+
+  constexpr size_t kNumOfKeys = 3;
+  std::array<std::string, kNumOfKeys> key_strs;
+  std::array<std::string, kNumOfKeys> value_strs;
+  std::array<Slice, kNumOfKeys + 1> keys;
+  for (size_t i = 0; i < kNumOfKeys; ++i) {
+    key_strs[i] = "foo" + std::to_string(i);
+    value_strs[i] = "blob_value" + std::to_string(i);
+    ASSERT_OK(Put(key_strs[i], value_strs[i]));
+    keys[i] = key_strs[i];
+  }
+
+  constexpr char key[] = "key";
+  {
+    // Fake a corrupt blob index.
+    const std::string blob_index("foobar");
+    WriteBatch batch;
+    ASSERT_OK(WriteBatchInternal::PutBlobIndex(&batch, 0, key, blob_index));
+    ASSERT_OK(db_->Write(WriteOptions(), &batch));
+    keys[kNumOfKeys] = Slice(static_cast<const char*>(key), sizeof(key) - 1);
+  }
+
+  ASSERT_OK(Flush());
+
+  std::array<PinnableSlice, kNumOfKeys + 1> values;
+  std::array<Status, kNumOfKeys + 1> statuses;
+  db_->MultiGet(ReadOptions(), dbfull()->DefaultColumnFamily(), kNumOfKeys + 1,
+                keys.data(), values.data(), statuses.data(),
+                /*sorted_input=*/false);
+  for (size_t i = 0; i < kNumOfKeys + 1; ++i) {
+    if (i != kNumOfKeys) {
+      ASSERT_OK(statuses[i]);
+      ASSERT_EQ("blob_value" + std::to_string(i), values[i]);
+    } else {
+      ASSERT_TRUE(statuses[i].IsCorruption());
+    }
+  }
+}
+
+TEST_F(DBBlobBasicTest, MultiGetBlob_ExceedSoftLimit) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  constexpr size_t kNumOfKeys = 3;
+  std::array<std::string, kNumOfKeys> key_bufs;
+  std::array<std::string, kNumOfKeys> value_bufs;
+  std::array<Slice, kNumOfKeys> keys;
+  for (size_t i = 0; i < kNumOfKeys; ++i) {
+    key_bufs[i] = "foo" + std::to_string(i);
+    value_bufs[i] = "blob_value" + std::to_string(i);
+    ASSERT_OK(Put(key_bufs[i], value_bufs[i]));
+    keys[i] = key_bufs[i];
+  }
+  ASSERT_OK(Flush());
+
+  std::array<PinnableSlice, kNumOfKeys> values;
+  std::array<Status, kNumOfKeys> statuses;
+  ReadOptions read_opts;
+  read_opts.value_size_soft_limit = 1;
+  db_->MultiGet(read_opts, dbfull()->DefaultColumnFamily(), kNumOfKeys,
+                keys.data(), values.data(), statuses.data(),
+                /*sorted_input=*/true);
+  for (const auto& s : statuses) {
+    ASSERT_TRUE(s.IsAborted());
+  }
+}
+
 TEST_F(DBBlobBasicTest, GetBlob_InlinedTTLIndex) {
  constexpr uint64_t min_blob_size = 10;

@@ -310,6 +620,212 @@ TEST_F(DBBlobBasicTest, BestEffortsRecovery_MissingNewestBlobFile) {
  ASSERT_EQ("value" + std::to_string(kNumTableFiles - 2), value);
 }

+TEST_F(DBBlobBasicTest, GetMergeBlobWithPut) {
+  Options options = GetDefaultOptions();
+  options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  ASSERT_OK(Put("Key1", "v1"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Merge("Key1", "v2"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Merge("Key1", "v3"));
+  ASSERT_OK(Flush());
+
+  std::string value;
+  ASSERT_OK(db_->Get(ReadOptions(), "Key1", &value));
+  ASSERT_EQ(Get("Key1"), "v1,v2,v3");
+}
+
+TEST_F(DBBlobBasicTest, MultiGetMergeBlobWithPut) {
+  constexpr size_t num_keys = 3;
+
+  Options options = GetDefaultOptions();
+  options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  ASSERT_OK(Put("Key0", "v0_0"));
+  ASSERT_OK(Put("Key1", "v1_0"));
+  ASSERT_OK(Put("Key2", "v2_0"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Merge("Key0", "v0_1"));
+  ASSERT_OK(Merge("Key1", "v1_1"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Merge("Key0", "v0_2"));
+  ASSERT_OK(Flush());
+
+  std::array<Slice, num_keys> keys{{"Key0", "Key1", "Key2"}};
+  std::array<PinnableSlice, num_keys> values;
+  std::array<Status, num_keys> statuses;
+
+  db_->MultiGet(ReadOptions(), db_->DefaultColumnFamily(), num_keys, &keys[0],
+                &values[0], &statuses[0]);
+
+  ASSERT_OK(statuses[0]);
+  ASSERT_EQ(values[0], "v0_0,v0_1,v0_2");
+
+  ASSERT_OK(statuses[1]);
+  ASSERT_EQ(values[1], "v1_0,v1_1");
+
+  ASSERT_OK(statuses[2]);
+  ASSERT_EQ(values[2], "v2_0");
+}
+
+#ifndef ROCKSDB_LITE
+TEST_F(DBBlobBasicTest, Properties) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  constexpr char key1[] = "key1";
+  constexpr size_t key1_size = sizeof(key1) - 1;
+
+  constexpr char key2[] = "key2";
+  constexpr size_t key2_size = sizeof(key2) - 1;
+
+  constexpr char key3[] = "key3";
+  constexpr size_t key3_size = sizeof(key3) - 1;
+
+  constexpr char blob[] = "00000000000000";
+  constexpr size_t blob_size = sizeof(blob) - 1;
+
+  constexpr char longer_blob[] = "00000000000000000000";
+  constexpr size_t longer_blob_size = sizeof(longer_blob) - 1;
+
+  ASSERT_OK(Put(key1, blob));
+  ASSERT_OK(Put(key2, longer_blob));
+  ASSERT_OK(Flush());
+
+  constexpr size_t first_blob_file_expected_size =
+      BlobLogHeader::kSize +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(key1_size) + blob_size +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(key2_size) +
+      longer_blob_size + BlobLogFooter::kSize;
+
+  ASSERT_OK(Put(key3, blob));
+  ASSERT_OK(Flush());
+
+  constexpr size_t second_blob_file_expected_size =
+      BlobLogHeader::kSize +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(key3_size) + blob_size +
+      BlobLogFooter::kSize;
+
+  constexpr size_t total_expected_size =
+      first_blob_file_expected_size + second_blob_file_expected_size;
+
+  // Number of blob files
+  uint64_t num_blob_files = 0;
+  ASSERT_TRUE(
+      db_->GetIntProperty(DB::Properties::kNumBlobFiles, &num_blob_files));
+  ASSERT_EQ(num_blob_files, 2);
+
+  // Total size of live blob files
+  uint64_t live_blob_file_size = 0;
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kLiveBlobFileSize,
+                                  &live_blob_file_size));
+  ASSERT_EQ(live_blob_file_size, total_expected_size);
+
+  // Total size of all blob files across all versions
+  // Note: this should be the same as above since we only have one
+  // version at this point.
+  uint64_t total_blob_file_size = 0;
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kTotalBlobFileSize,
+                                  &total_blob_file_size));
+  ASSERT_EQ(total_blob_file_size, total_expected_size);
+
+  // Delete key2 to create some garbage
+  ASSERT_OK(Delete(key2));
+  ASSERT_OK(Flush());
+
+  constexpr Slice* begin = nullptr;
+  constexpr Slice* end = nullptr;
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), begin, end));
+
+  constexpr size_t expected_garbage_size =
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(key2_size) +
+      longer_blob_size;
+
+  constexpr double expected_space_amp =
+      static_cast<double>(total_expected_size) /
+      (total_expected_size - expected_garbage_size);
+
+  // Blob file stats
+  std::string blob_stats;
+  ASSERT_TRUE(db_->GetProperty(DB::Properties::kBlobStats, &blob_stats));
+
+  std::ostringstream oss;
+  oss << "Number of blob files: 2\nTotal size of blob files: "
+      << total_expected_size
+      << "\nTotal size of garbage in blob files: " << expected_garbage_size
+      << "\nBlob file space amplification: " << expected_space_amp << '\n';
+
+  ASSERT_EQ(blob_stats, oss.str());
+}
+
+TEST_F(DBBlobBasicTest, PropertiesMultiVersion) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  constexpr char key1[] = "key1";
+  constexpr char key2[] = "key2";
+  constexpr char key3[] = "key3";
+
+  constexpr size_t key_size = sizeof(key1) - 1;
+  static_assert(sizeof(key2) - 1 == key_size, "unexpected size: key2");
+  static_assert(sizeof(key3) - 1 == key_size, "unexpected size: key3");
+
+  constexpr char blob[] = "0000000000";
+  constexpr size_t blob_size = sizeof(blob) - 1;
+
+  ASSERT_OK(Put(key1, blob));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(Put(key2, blob));
+  ASSERT_OK(Flush());
+
+  // Create an iterator to keep the current version alive
+  std::unique_ptr<Iterator> iter(db_->NewIterator(ReadOptions()));
+  ASSERT_OK(iter->status());
+
+  // Note: the Delete and subsequent compaction results in the first blob file
+  // not making it to the final version. (It is still part of the previous
+  // version kept alive by the iterator though.) On the other hand, the Put
+  // results in a third blob file.
+  ASSERT_OK(Delete(key1));
+  ASSERT_OK(Put(key3, blob));
+  ASSERT_OK(Flush());
+
+  constexpr Slice* begin = nullptr;
+  constexpr Slice* end = nullptr;
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), begin, end));
+
+  // Total size of all blob files across all versions: between the two versions,
+  // we should have three blob files of the same size with one blob each.
+  // The version kept alive by the iterator contains the first and the second
+  // blob file, while the final version contains the second and the third blob
+  // file. (The second blob file is thus shared by the two versions but should
+  // be counted only once.)
+  uint64_t total_blob_file_size = 0;
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kTotalBlobFileSize,
+                                  &total_blob_file_size));
+  ASSERT_EQ(total_blob_file_size,
+            3 * (BlobLogHeader::kSize +
+                 BlobLogRecord::CalculateAdjustmentForRecordHeader(key_size) +
+                 blob_size + BlobLogFooter::kSize));
+}
+#endif  // !ROCKSDB_LITE
+
 class DBBlobBasicIOErrorTest : public DBBlobBasicTest,
                               public testing::WithParamInterface<std::string> {
 protected:
@@ -322,11 +838,21 @@ class DBBlobBasicIOErrorTest : public DBBlobBasicTest,
  std::string sync_point_;
 };

+class DBBlobBasicIOErrorMultiGetTest : public DBBlobBasicIOErrorTest {
+ public:
+  DBBlobBasicIOErrorMultiGetTest() : DBBlobBasicIOErrorTest() {}
+};
+
 INSTANTIATE_TEST_CASE_P(DBBlobBasicTest, DBBlobBasicIOErrorTest,
                        ::testing::ValuesIn(std::vector<std::string>{
                            "BlobFileReader::OpenFile:NewRandomAccessFile",
                            "BlobFileReader::GetBlob:ReadFromFile"}));

+INSTANTIATE_TEST_CASE_P(DBBlobBasicTest, DBBlobBasicIOErrorMultiGetTest,
+                        ::testing::ValuesIn(std::vector<std::string>{
+                            "BlobFileReader::OpenFile:NewRandomAccessFile",
+                            "BlobFileReader::MultiGetBlob:ReadFromFile"}));
+
 TEST_P(DBBlobBasicIOErrorTest, GetBlob_IOError) {
  Options options;
  options.env = fault_injection_env_.get();
@@ -356,7 +882,7 @@ TEST_P(DBBlobBasicIOErrorTest, GetBlob_IOError) {
  SyncPoint::GetInstance()->ClearAllCallBacks();
 }

-TEST_P(DBBlobBasicIOErrorTest, MultiGetBlobs_IOError) {
+TEST_P(DBBlobBasicIOErrorMultiGetTest, MultiGetBlobs_IOError) {
  Options options = GetDefaultOptions();
  options.env = fault_injection_env_.get();
  options.enable_blob_files = true;
@@ -398,6 +924,53 @@ TEST_P(DBBlobBasicIOErrorTest, MultiGetBlobs_IOError) {
  ASSERT_TRUE(statuses[1].IsIOError());
 }

+TEST_P(DBBlobBasicIOErrorMultiGetTest, MultipleBlobFiles) {
+  Options options = GetDefaultOptions();
+  options.env = fault_injection_env_.get();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  Reopen(options);
+
+  constexpr size_t num_keys = 2;
+
+  constexpr char key1[] = "key1";
+  constexpr char value1[] = "blob1";
+
+  ASSERT_OK(Put(key1, value1));
+  ASSERT_OK(Flush());
+
+  constexpr char key2[] = "key2";
+  constexpr char value2[] = "blob2";
+
+  ASSERT_OK(Put(key2, value2));
+  ASSERT_OK(Flush());
+
+  std::array<Slice, num_keys> keys{{key1, key2}};
+  std::array<PinnableSlice, num_keys> values;
+  std::array<Status, num_keys> statuses;
+
+  bool first_blob_file = true;
+  SyncPoint::GetInstance()->SetCallBack(
+      sync_point_, [&first_blob_file, this](void* /* arg */) {
+        if (first_blob_file) {
+          first_blob_file = false;
+          return;
+        }
+        fault_injection_env_->SetFilesystemActive(false,
+                                                  Status::IOError(sync_point_));
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  db_->MultiGet(ReadOptions(), db_->DefaultColumnFamily(), num_keys,
+                keys.data(), values.data(), statuses.data());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  ASSERT_OK(statuses[0]);
+  ASSERT_EQ(value1, values[0]);
+  ASSERT_TRUE(statuses[1].IsIOError());
+}
+
 namespace {

 class ReadBlobCompactionFilter : public CompactionFilter {
@@ -456,5 +1029,6 @@ TEST_P(DBBlobBasicIOErrorTest, CompactionFilterReadBlob_IOError) {
 int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
  return RUN_ALL_TESTS();
 }
@@ -4,21 +4,21 @@
 //  (found in the LICENSE.Apache file in the root directory).

 #include "db/blob/blob_index.h"
+#include "db/blob/blob_log_format.h"
 #include "db/db_test_util.h"
 #include "port/stack_trace.h"
 #include "test_util/sync_point.h"
-#include "utilities/fault_injection_env.h"

 namespace ROCKSDB_NAMESPACE {

 class DBBlobCompactionTest : public DBTestBase {
 public:
  explicit DBBlobCompactionTest()
-      : DBTestBase("/db_blob_compaction_test", /*env_do_fsync=*/false) {}
+      : DBTestBase("db_blob_compaction_test", /*env_do_fsync=*/false) {}

 #ifndef ROCKSDB_LITE
  const std::vector<InternalStats::CompactionStats>& GetCompactionStats() {
-    VersionSet* const versions = dbfull()->TEST_GetVersionSet();
+    VersionSet* const versions = dbfull()->GetVersionSet();
    assert(versions);
    assert(versions->GetColumnFamilySet());

@@ -152,6 +152,31 @@ class AlwaysKeepFilter : public CompactionFilter {
    return CompactionFilter::Decision::kKeep;
  }
 };
+
+class SkipUntilFilter : public CompactionFilter {
+ public:
+  explicit SkipUntilFilter(std::string skip_until)
+      : skip_until_(std::move(skip_until)) {}
+
+  const char* Name() const override {
+    return "rocksdb.compaction.filter.skip.until";
+  }
+
+  CompactionFilter::Decision FilterV2(int /* level */, const Slice& /* key */,
+                                      ValueType /* value_type */,
+                                      const Slice& /* existing_value */,
+                                      std::string* /* new_value */,
+                                      std::string* skip_until) const override {
+    assert(skip_until);
+    *skip_until = skip_until_;
+
+    return CompactionFilter::Decision::kRemoveAndSkipUntil;
+  }
+
+ private:
+  std::string skip_until_;
+};
+
 }  // anonymous namespace

 class DBBlobBadCompactionFilterTest
@@ -254,6 +279,49 @@ TEST_F(DBBlobCompactionTest, BlindWriteFilter) {
  Close();
 }

+TEST_F(DBBlobCompactionTest, SkipUntilFilter) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+
+  std::unique_ptr<CompactionFilter> compaction_filter_guard(
+      new SkipUntilFilter("z"));
+  options.compaction_filter = compaction_filter_guard.get();
+
+  Reopen(options);
+
+  const std::vector<std::string> keys{"a", "b", "c"};
+  const std::vector<std::string> values{"a_value", "b_value", "c_value"};
+  assert(keys.size() == values.size());
+
+  for (size_t i = 0; i < keys.size(); ++i) {
+    ASSERT_OK(Put(keys[i], values[i]));
+  }
+
+  ASSERT_OK(Flush());
+
+  int process_in_flow_called = 0;
+
+  SyncPoint::GetInstance()->SetCallBack(
+      "BlobCountingIterator::UpdateAndCountBlobIfNeeded:ProcessInFlow",
+      [&process_in_flow_called](void* /* arg */) { ++process_in_flow_called; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), /* begin */ nullptr,
+                              /* end */ nullptr));
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  for (const auto& key : keys) {
+    ASSERT_EQ(Get(key), "NOT_FOUND");
+  }
+
+  // Make sure SkipUntil was performed using iteration rather than Seek
+  ASSERT_EQ(process_in_flow_called, keys.size());
+
+  Close();
+}
+
 TEST_P(DBBlobBadCompactionFilterTest, BadDecisionFromCompactionFilter) {
  Options options = GetDefaultOptions();
  options.enable_blob_files = true;
@@ -390,10 +458,259 @@ TEST_F(DBBlobCompactionTest, CompactionFilterReadBlobAndKeep) {
  Close();
 }

+TEST_F(DBBlobCompactionTest, TrackGarbage) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+
+  Reopen(options);
+
+  // First table+blob file pair: 4 blobs with different keys
+  constexpr char first_key[] = "first_key";
+  constexpr char first_value[] = "first_value";
+  constexpr char second_key[] = "second_key";
+  constexpr char second_value[] = "second_value";
+  constexpr char third_key[] = "third_key";
+  constexpr char third_value[] = "third_value";
+  constexpr char fourth_key[] = "fourth_key";
+  constexpr char fourth_value[] = "fourth_value";
+
+  ASSERT_OK(Put(first_key, first_value));
+  ASSERT_OK(Put(second_key, second_value));
+  ASSERT_OK(Put(third_key, third_value));
+  ASSERT_OK(Put(fourth_key, fourth_value));
+  ASSERT_OK(Flush());
+
+  // Second table+blob file pair: overwrite 2 existing keys
+  constexpr char new_first_value[] = "new_first_value";
+  constexpr char new_second_value[] = "new_second_value";
+
+  ASSERT_OK(Put(first_key, new_first_value));
+  ASSERT_OK(Put(second_key, new_second_value));
+  ASSERT_OK(Flush());
+
+  // Compact them together. The first blob file should have 2 garbage blobs
+  // corresponding to the 2 overwritten keys.
+  constexpr Slice* begin = nullptr;
+  constexpr Slice* end = nullptr;
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), begin, end));
+
+  VersionSet* const versions = dbfull()->GetVersionSet();
+  assert(versions);
+  assert(versions->GetColumnFamilySet());
+
+  ColumnFamilyData* const cfd = versions->GetColumnFamilySet()->GetDefault();
+  assert(cfd);
+
+  Version* const current = cfd->current();
+  assert(current);
+
+  const VersionStorageInfo* const storage_info = current->storage_info();
+  assert(storage_info);
+
+  const auto& blob_files = storage_info->GetBlobFiles();
+  ASSERT_EQ(blob_files.size(), 2);
+
+  {
+    const auto& meta = blob_files.front();
+    assert(meta);
+
+    constexpr uint64_t first_expected_bytes =
+        sizeof(first_value) - 1 +
+        BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(first_key) -
+                                                          1);
+    constexpr uint64_t second_expected_bytes =
+        sizeof(second_value) - 1 +
+        BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(second_key) -
+                                                          1);
+    constexpr uint64_t third_expected_bytes =
+        sizeof(third_value) - 1 +
+        BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(third_key) -
+                                                          1);
+    constexpr uint64_t fourth_expected_bytes =
+        sizeof(fourth_value) - 1 +
+        BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(fourth_key) -
+                                                          1);
+
+    ASSERT_EQ(meta->GetTotalBlobCount(), 4);
+    ASSERT_EQ(meta->GetTotalBlobBytes(),
+              first_expected_bytes + second_expected_bytes +
+                  third_expected_bytes + fourth_expected_bytes);
+    ASSERT_EQ(meta->GetGarbageBlobCount(), 2);
+    ASSERT_EQ(meta->GetGarbageBlobBytes(),
+              first_expected_bytes + second_expected_bytes);
+  }
+
+  {
+    const auto& meta = blob_files.back();
+    assert(meta);
+
+    constexpr uint64_t new_first_expected_bytes =
+        sizeof(new_first_value) - 1 +
+        BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(first_key) -
+                                                          1);
+    constexpr uint64_t new_second_expected_bytes =
+        sizeof(new_second_value) - 1 +
+        BlobLogRecord::CalculateAdjustmentForRecordHeader(sizeof(second_key) -
+                                                          1);
+
+    ASSERT_EQ(meta->GetTotalBlobCount(), 2);
+    ASSERT_EQ(meta->GetTotalBlobBytes(),
+              new_first_expected_bytes + new_second_expected_bytes);
+    ASSERT_EQ(meta->GetGarbageBlobCount(), 0);
+    ASSERT_EQ(meta->GetGarbageBlobBytes(), 0);
+  }
+}
+
+TEST_F(DBBlobCompactionTest, MergeBlobWithBase) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+  options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  options.disable_auto_compactions = true;
+
+  Reopen(options);
+  ASSERT_OK(Put("Key1", "v1_1"));
+  ASSERT_OK(Put("Key2", "v2_1"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(Merge("Key1", "v1_2"));
+  ASSERT_OK(Merge("Key2", "v2_2"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(Merge("Key1", "v1_3"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), /*begin=*/nullptr,
+                              /*end=*/nullptr));
+  ASSERT_EQ(Get("Key1"), "v1_1,v1_2,v1_3");
+  ASSERT_EQ(Get("Key2"), "v2_1,v2_2");
+  Close();
+}
+
+TEST_F(DBBlobCompactionTest, CompactionReadaheadGarbageCollection) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+  options.enable_blob_garbage_collection = true;
+  options.blob_garbage_collection_age_cutoff = 1.0;
+  options.blob_compaction_readahead_size = 1 << 10;
+  options.disable_auto_compactions = true;
+
+  Reopen(options);
+
+  ASSERT_OK(Put("key", "lime"));
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(Put("key", "pie"));
+  ASSERT_OK(Put("foo", "baz"));
+  ASSERT_OK(Flush());
+
+  size_t num_non_prefetch_reads = 0;
+  SyncPoint::GetInstance()->SetCallBack(
+      "BlobFileReader::GetBlob:ReadFromFile",
+      [&num_non_prefetch_reads](void* /* arg */) { ++num_non_prefetch_reads; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  constexpr Slice* begin = nullptr;
+  constexpr Slice* end = nullptr;
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), begin, end));
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  ASSERT_EQ(Get("key"), "pie");
+  ASSERT_EQ(Get("foo"), "baz");
+  ASSERT_EQ(num_non_prefetch_reads, 0);
+
+  Close();
+}
+
+TEST_F(DBBlobCompactionTest, CompactionReadaheadFilter) {
+  Options options = GetDefaultOptions();
+
+  std::unique_ptr<CompactionFilter> compaction_filter_guard(
+      new ValueMutationFilter("pie"));
+
+  options.compaction_filter = compaction_filter_guard.get();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+  options.blob_compaction_readahead_size = 1 << 10;
+  options.disable_auto_compactions = true;
+
+  Reopen(options);
+
+  ASSERT_OK(Put("key", "lime"));
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Flush());
+
+  size_t num_non_prefetch_reads = 0;
+  SyncPoint::GetInstance()->SetCallBack(
+      "BlobFileReader::GetBlob:ReadFromFile",
+      [&num_non_prefetch_reads](void* /* arg */) { ++num_non_prefetch_reads; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  constexpr Slice* begin = nullptr;
+  constexpr Slice* end = nullptr;
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), begin, end));
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  ASSERT_EQ(Get("key"), "limepie");
+  ASSERT_EQ(Get("foo"), "barpie");
+  ASSERT_EQ(num_non_prefetch_reads, 0);
+
+  Close();
+}
+
+TEST_F(DBBlobCompactionTest, CompactionReadaheadMerge) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+  options.blob_compaction_readahead_size = 1 << 10;
+  options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  options.disable_auto_compactions = true;
+
+  Reopen(options);
+
+  ASSERT_OK(Put("key", "lime"));
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(Merge("key", "pie"));
+  ASSERT_OK(Merge("foo", "baz"));
+  ASSERT_OK(Flush());
+
+  size_t num_non_prefetch_reads = 0;
+  SyncPoint::GetInstance()->SetCallBack(
+      "BlobFileReader::GetBlob:ReadFromFile",
+      [&num_non_prefetch_reads](void* /* arg */) { ++num_non_prefetch_reads; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  constexpr Slice* begin = nullptr;
+  constexpr Slice* end = nullptr;
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), begin, end));
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  ASSERT_EQ(Get("key"), "lime,pie");
+  ASSERT_EQ(Get("foo"), "bar,baz");
+  ASSERT_EQ(num_non_prefetch_reads, 0);
+
+  Close();
+}
+
 }  // namespace ROCKSDB_NAMESPACE

 int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
  return RUN_ALL_TESTS();
 }
@@ -12,7 +12,7 @@ namespace ROCKSDB_NAMESPACE {
 class DBBlobCorruptionTest : public DBTestBase {
 protected:
  DBBlobCorruptionTest()
-      : DBTestBase("/db_blob_corruption_test", /* env_do_fsync */ false) {}
+      : DBTestBase("db_blob_corruption_test", /* env_do_fsync */ false) {}

  void Corrupt(FileType filetype, int offset, int bytes_to_corrupt) {
    // Pick file to corrupt
@@ -77,5 +77,6 @@ TEST_F(DBBlobCorruptionTest, VerifyWholeBlobFileChecksum) {
 int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
  return RUN_ALL_TESTS();
 }
@@ -41,8 +41,7 @@ class DBBlobIndexTest : public DBTestBase {
                                       Tier::kImmutableMemtables,
                                       Tier::kL0SstFile, Tier::kLnSstFile};

-  DBBlobIndexTest()
-      : DBTestBase("/db_blob_index_test", /*env_do_fsync=*/true) {}
+  DBBlobIndexTest() : DBTestBase("db_blob_index_test", /*env_do_fsync=*/true) {}

  ColumnFamilyHandle* cfh() { return dbfull()->DefaultColumnFamily(); }

@@ -399,7 +398,7 @@ TEST_F(DBBlobIndexTest, Iterate) {
           create_normal_iterator);
    verify(9, Status::kOk, get_value(10, 0), get_value(8, 0),
           create_normal_iterator);
-    verify(11, Status::kNotSupported, "", "", create_normal_iterator);
+    verify(11, Status::kCorruption, "", "", create_normal_iterator);
    verify(13, Status::kOk,
           get_value(13, 2) + "," + get_value(13, 1) + "," + get_value(13, 0),
           get_value(13, 2) + "," + get_value(13, 1) + "," + get_value(13, 0),
@@ -418,7 +417,11 @@ TEST_F(DBBlobIndexTest, Iterate) {
           create_blob_iterator, check_is_blob(false));
    verify(9, Status::kOk, get_value(10, 0), get_value(8, 0),
           create_blob_iterator, check_is_blob(false));
-    verify(11, Status::kNotSupported, "", "", create_blob_iterator);
+    if (tier <= kImmutableMemtables) {
+      verify(11, Status::kNotSupported, "", "", create_blob_iterator);
+    } else {
+      verify(11, Status::kCorruption, "", "", create_blob_iterator);
+    }
    verify(13, Status::kOk,
           get_value(13, 2) + "," + get_value(13, 1) + "," + get_value(13, 0),
           get_value(13, 2) + "," + get_value(13, 1) + "," + get_value(13, 0),
@@ -440,7 +443,11 @@ TEST_F(DBBlobIndexTest, Iterate) {
           create_blob_iterator, check_is_blob(false));
    verify(9, Status::kOk, get_value(10, 0), get_value(8, 0),
           create_blob_iterator, check_is_blob(false));
-    verify(11, Status::kNotSupported, "", "", create_blob_iterator);
+    if (tier <= kImmutableMemtables) {
+      verify(11, Status::kNotSupported, "", "", create_blob_iterator);
+    } else {
+      verify(11, Status::kCorruption, "", "", create_blob_iterator);
+    }
    verify(13, Status::kOk,
           get_value(13, 2) + "," + get_value(13, 1) + "," + get_value(13, 0),
           get_value(13, 2) + "," + get_value(13, 1) + "," + get_value(13, 0),
@@ -455,10 +462,111 @@ TEST_F(DBBlobIndexTest, Iterate) {
  }
 }

+TEST_F(DBBlobIndexTest, IntegratedBlobIterate) {
+  const std::vector<std::vector<std::string>> data = {
+      /*00*/ {"Put"},
+      /*01*/ {"Put", "Merge", "Merge", "Merge"},
+      /*02*/ {"Put"}};
+
+  auto get_key = [](size_t index) { return ("key" + std::to_string(index)); };
+
+  auto get_value = [&](size_t index, size_t version) {
+    return get_key(index) + "_value" + ToString(version);
+  };
+
+  auto check_iterator = [&](Iterator* iterator, Status expected_status,
+                            const Slice& expected_value) {
+    ASSERT_EQ(expected_status, iterator->status());
+    if (expected_status.ok()) {
+      ASSERT_TRUE(iterator->Valid());
+      ASSERT_EQ(expected_value, iterator->value());
+    } else {
+      ASSERT_FALSE(iterator->Valid());
+    }
+  };
+
+  auto verify = [&](size_t index, Status expected_status,
+                    const Slice& expected_value) {
+    // Seek
+    {
+      Iterator* iterator = db_->NewIterator(ReadOptions());
+      std::unique_ptr<Iterator> iterator_guard(iterator);
+      ASSERT_OK(iterator->status());
+      ASSERT_OK(iterator->Refresh());
+      iterator->Seek(get_key(index));
+      check_iterator(iterator, expected_status, expected_value);
+    }
+    // Next
+    {
+      Iterator* iterator = db_->NewIterator(ReadOptions());
+      std::unique_ptr<Iterator> iterator_guard(iterator);
+      ASSERT_OK(iterator->Refresh());
+      iterator->Seek(get_key(index - 1));
+      ASSERT_TRUE(iterator->Valid());
+      ASSERT_OK(iterator->status());
+      iterator->Next();
+      check_iterator(iterator, expected_status, expected_value);
+    }
+    // SeekForPrev
+    {
+      Iterator* iterator = db_->NewIterator(ReadOptions());
+      std::unique_ptr<Iterator> iterator_guard(iterator);
+      ASSERT_OK(iterator->status());
+      ASSERT_OK(iterator->Refresh());
+      iterator->SeekForPrev(get_key(index));
+      check_iterator(iterator, expected_status, expected_value);
+    }
+    // Prev
+    {
+      Iterator* iterator = db_->NewIterator(ReadOptions());
+      std::unique_ptr<Iterator> iterator_guard(iterator);
+      iterator->Seek(get_key(index + 1));
+      ASSERT_TRUE(iterator->Valid());
+      ASSERT_OK(iterator->status());
+      iterator->Prev();
+      check_iterator(iterator, expected_status, expected_value);
+    }
+  };
+
+  Options options = GetTestOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+
+  DestroyAndReopen(options);
+
+  // fill data
+  for (size_t i = 0; i < data.size(); i++) {
+    for (size_t j = 0; j < data[i].size(); j++) {
+      std::string key = get_key(i);
+      std::string value = get_value(i, j);
+      if (data[i][j] == "Put") {
+        ASSERT_OK(Put(key, value));
+        ASSERT_OK(Flush());
+      } else if (data[i][j] == "Merge") {
+        ASSERT_OK(Merge(key, value));
+        ASSERT_OK(Flush());
+      }
+    }
+  }
+
+  std::string expected_value = get_value(1, 0) + "," + get_value(1, 1) + "," +
+                               get_value(1, 2) + "," + get_value(1, 3);
+  Status expected_status;
+  verify(1, expected_status, expected_value);
+
+#ifndef ROCKSDB_LITE
+  // Test DBIter::FindValueForCurrentKeyUsingSeek flow.
+  ASSERT_OK(dbfull()->SetOptions(cfh(),
+                                 {{"max_sequential_skip_in_iterations", "0"}}));
+  verify(1, expected_status, expected_value);
+#endif  // !ROCKSDB_LITE
+}
+
 }  // namespace ROCKSDB_NAMESPACE

 int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
  return RUN_ALL_TESTS();
 }
@@ -0,0 +1,21 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/prefetch_buffer_collection.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+FilePrefetchBuffer* PrefetchBufferCollection::GetOrCreatePrefetchBuffer(
+    uint64_t file_number) {
+  auto& prefetch_buffer = prefetch_buffers_[file_number];
+  if (!prefetch_buffer) {
+    prefetch_buffer.reset(
+        new FilePrefetchBuffer(readahead_size_, readahead_size_));
+  }
+
+  return prefetch_buffer.get();
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,38 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <cassert>
+#include <cstdint>
+#include <memory>
+#include <unordered_map>
+
+#include "file/file_prefetch_buffer.h"
+#include "rocksdb/rocksdb_namespace.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// A class that owns a collection of FilePrefetchBuffers using the file number
+// as key. Used for implementing compaction readahead for blob files. Designed
+// to be accessed by a single thread only: every (sub)compaction needs its own
+// buffers since they are guaranteed to read different blobs from different
+// positions even when reading the same file.
+class PrefetchBufferCollection {
+ public:
+  explicit PrefetchBufferCollection(uint64_t readahead_size)
+      : readahead_size_(readahead_size) {
+    assert(readahead_size_ > 0);
+  }
+
+  FilePrefetchBuffer* GetOrCreatePrefetchBuffer(uint64_t file_number);
+
+ private:
+  uint64_t readahead_size_;
+  std::unordered_map<uint64_t, std::unique_ptr<FilePrefetchBuffer>>
+      prefetch_buffers_;  // maps file number to prefetch buffer
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -15,7 +15,6 @@

 #include "db/blob/blob_file_builder.h"
 #include "db/compaction/compaction_iterator.h"
-#include "db/dbformat.h"
 #include "db/event_helpers.h"
 #include "db/internal_stats.h"
 #include "db/merge_helper.h"
@@ -45,62 +44,42 @@ namespace ROCKSDB_NAMESPACE {

 class TableFactory;

-TableBuilder* NewTableBuilder(
-    const ImmutableCFOptions& ioptions, const MutableCFOptions& moptions,
-    const InternalKeyComparator& internal_comparator,
-    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-        int_tbl_prop_collector_factories,
-    uint32_t column_family_id, const std::string& column_family_name,
-    WritableFileWriter* file, const CompressionType compression_type,
-    const CompressionOptions& compression_opts, int level,
-    const bool skip_filters, const uint64_t creation_time,
-    const uint64_t oldest_key_time, const uint64_t target_file_size,
-    const uint64_t file_creation_time, const std::string& db_id,
-    const std::string& db_session_id) {
-  assert((column_family_id ==
+TableBuilder* NewTableBuilder(const TableBuilderOptions& tboptions,
+                              WritableFileWriter* file) {
+  assert((tboptions.column_family_id ==
          TablePropertiesCollectorFactory::Context::kUnknownColumnFamily) ==
-         column_family_name.empty());
-  return ioptions.table_factory->NewTableBuilder(
-      TableBuilderOptions(ioptions, moptions, internal_comparator,
-                          int_tbl_prop_collector_factories, compression_type,
-                          compression_opts, skip_filters, column_family_name,
-                          level, creation_time, oldest_key_time,
-                          target_file_size, file_creation_time, db_id,
-                          db_session_id),
-      column_family_id, file);
+         tboptions.column_family_name.empty());
+  return tboptions.ioptions.table_factory->NewTableBuilder(tboptions, file);
 }

 Status BuildTable(
    const std::string& dbname, VersionSet* versions,
-    const ImmutableDBOptions& db_options, const ImmutableCFOptions& ioptions,
-    const MutableCFOptions& mutable_cf_options, const FileOptions& file_options,
-    TableCache* table_cache, InternalIterator* iter,
+    const ImmutableDBOptions& db_options, const TableBuilderOptions& tboptions,
+    const FileOptions& file_options, TableCache* table_cache,
+    InternalIterator* iter,
    std::vector<std::unique_ptr<FragmentedRangeTombstoneIterator>>
        range_del_iters,
    FileMetaData* meta, std::vector<BlobFileAddition>* blob_file_additions,
-    const InternalKeyComparator& internal_comparator,
-    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-        int_tbl_prop_collector_factories,
-    uint32_t column_family_id, const std::string& column_family_name,
    std::vector<SequenceNumber> snapshots,
    SequenceNumber earliest_write_conflict_snapshot,
-    SnapshotChecker* snapshot_checker, const CompressionType compression,
-    const CompressionOptions& compression_opts, bool paranoid_file_checks,
-    InternalStats* internal_stats, TableFileCreationReason reason,
-    IOStatus* io_status, const std::shared_ptr<IOTracer>& io_tracer,
-    EventLogger* event_logger, int job_id, const Env::IOPriority io_priority,
-    TableProperties* table_properties, int level, const uint64_t creation_time,
-    const uint64_t oldest_key_time, Env::WriteLifeTimeHint write_hint,
-    const uint64_t file_creation_time, const std::string& db_id,
-    const std::string& db_session_id, const std::string* full_history_ts_low,
-    BlobFileCompletionCallback* blob_callback) {
-  assert((column_family_id ==
+    SnapshotChecker* snapshot_checker, bool paranoid_file_checks,
+    InternalStats* internal_stats, IOStatus* io_status,
+    const std::shared_ptr<IOTracer>& io_tracer,
+    BlobFileCreationReason blob_creation_reason, EventLogger* event_logger,
+    int job_id, const Env::IOPriority io_priority,
+    TableProperties* table_properties, Env::WriteLifeTimeHint write_hint,
+    const std::string* full_history_ts_low,
+    BlobFileCompletionCallback* blob_callback, uint64_t* num_input_entries,
+    uint64_t* memtable_payload_bytes, uint64_t* memtable_garbage_bytes) {
+  assert((tboptions.column_family_id ==
          TablePropertiesCollectorFactory::Context::kUnknownColumnFamily) ==
-         column_family_name.empty());
+         tboptions.column_family_name.empty());
+  auto& mutable_cf_options = tboptions.moptions;
+  auto& ioptions = tboptions.ioptions;
  // Reports the IOStats for flush for every following bytes.
  const size_t kReportFlushIOStatsEvery = 1048576;
  OutputValidator output_validator(
-      internal_comparator,
+      tboptions.internal_comparator,
      /*enable_order_check=*/
      mutable_cf_options.check_flush_compaction_key_order,
      /*enable_hash=*/paranoid_file_checks);
@@ -108,8 +87,15 @@ Status BuildTable(
  meta->fd.file_size = 0;
  iter->SeekToFirst();
  std::unique_ptr<CompactionRangeDelAggregator> range_del_agg(
-      new CompactionRangeDelAggregator(&internal_comparator, snapshots));
+      new CompactionRangeDelAggregator(&tboptions.internal_comparator,
+                                       snapshots));
+  uint64_t num_unfragmented_tombstones = 0;
+  uint64_t total_tombstone_payload_bytes = 0;
  for (auto& range_del_iter : range_del_iters) {
+    num_unfragmented_tombstones +=
+        range_del_iter->num_unfragmented_tombstones();
+    total_tombstone_payload_bytes +=
+        range_del_iter->total_tombstone_payload_bytes();
    range_del_agg->AddTombstones(std::move(range_del_iter));
  }

@@ -119,8 +105,9 @@ Status BuildTable(
  std::string file_checksum = kUnknownFileChecksum;
  std::string file_checksum_func_name = kUnknownFileChecksumFuncName;
 #ifndef ROCKSDB_LITE
-  EventHelpers::NotifyTableFileCreationStarted(
-      ioptions.listeners, dbname, column_family_name, fname, job_id, reason);
+  EventHelpers::NotifyTableFileCreationStarted(ioptions.listeners, dbname,
+                                               tboptions.column_family_name,
+                                               fname, job_id, tboptions.reason);
 #endif  // !ROCKSDB_LITE
  Env* env = db_options.env;
  assert(env);
@@ -129,6 +116,26 @@ Status BuildTable(

  TableProperties tp;
  if (iter->Valid() || !range_del_agg->IsEmpty()) {
+    std::unique_ptr<CompactionFilter> compaction_filter;
+    if (ioptions.compaction_filter_factory != nullptr &&
+        ioptions.compaction_filter_factory->ShouldFilterTableFileCreation(
+            tboptions.reason)) {
+      CompactionFilter::Context context;
+      context.is_full_compaction = false;
+      context.is_manual_compaction = false;
+      context.column_family_id = tboptions.column_family_id;
+      context.reason = tboptions.reason;
+      compaction_filter =
+          ioptions.compaction_filter_factory->CreateCompactionFilter(context);
+      if (compaction_filter != nullptr &&
+          !compaction_filter->IgnoreSnapshots()) {
+        s.PermitUncheckedError();
+        return Status::NotSupported(
+            "CompactionFilter::IgnoreSnapshots() = false is not supported "
+            "anymore.");
+      }
+    }
+
    TableBuilder* builder;
    std::unique_ptr<WritableFileWriter> file_writer;
    {
@@ -145,9 +152,10 @@ Status BuildTable(
      }
      if (!s.ok()) {
        EventHelpers::LogAndNotifyTableFileCreationFinished(
-            event_logger, ioptions.listeners, dbname, column_family_name, fname,
-            job_id, meta->fd, kInvalidBlobFileNumber, tp, reason, s,
-            file_checksum, file_checksum_func_name);
+            event_logger, ioptions.listeners, dbname,
+            tboptions.column_family_name, fname, job_id, meta->fd,
+            kInvalidBlobFileNumber, tp, tboptions.reason, s, file_checksum,
+            file_checksum_func_name);
        return s;
      }
      FileTypeSet tmp_set = ioptions.checksum_handoff_file_types;
@@ -155,43 +163,40 @@ Status BuildTable(
      file->SetWriteLifeTimeHint(write_hint);
      file_writer.reset(new WritableFileWriter(
          std::move(file), fname, file_options, ioptions.clock, io_tracer,
-          ioptions.statistics, ioptions.listeners,
+          ioptions.stats, ioptions.listeners,
          ioptions.file_checksum_gen_factory.get(),
-          tmp_set.Contains(FileType::kTableFile)));
+          tmp_set.Contains(FileType::kTableFile), false));

-      builder = NewTableBuilder(
-          ioptions, mutable_cf_options, internal_comparator,
-          int_tbl_prop_collector_factories, column_family_id,
-          column_family_name, file_writer.get(), compression, compression_opts,
-          level, false /* skip_filters */, creation_time, oldest_key_time,
-          0 /*target_file_size*/, file_creation_time, db_id, db_session_id);
+      builder = NewTableBuilder(tboptions, file_writer.get());
    }

-    MergeHelper merge(env, internal_comparator.user_comparator(),
-                      ioptions.merge_operator.get(), nullptr, ioptions.info_log,
-                      true /* internal key corruption is not ok */,
-                      snapshots.empty() ? 0 : snapshots.back(),
-                      snapshot_checker);
+    MergeHelper merge(
+        env, tboptions.internal_comparator.user_comparator(),
+        ioptions.merge_operator.get(), compaction_filter.get(), ioptions.logger,
+        true /* internal key corruption is not ok */,
+        snapshots.empty() ? 0 : snapshots.back(), snapshot_checker);

    std::unique_ptr<BlobFileBuilder> blob_file_builder(
        (mutable_cf_options.enable_blob_files && blob_file_additions)
-            ? new BlobFileBuilder(versions, fs, &ioptions, &mutable_cf_options,
-                                  &file_options, job_id, column_family_id,
-                                  column_family_name, io_priority, write_hint,
-                                  io_tracer, blob_callback, &blob_file_paths,
-                                  blob_file_additions)
+            ? new BlobFileBuilder(
+                  versions, fs, &ioptions, &mutable_cf_options, &file_options,
+                  job_id, tboptions.column_family_id,
+                  tboptions.column_family_name, io_priority, write_hint,
+                  io_tracer, blob_callback, blob_creation_reason,
+                  &blob_file_paths, blob_file_additions)
            : nullptr);

    CompactionIterator c_iter(
-        iter, internal_comparator.user_comparator(), &merge, kMaxSequenceNumber,
-        &snapshots, earliest_write_conflict_snapshot, snapshot_checker, env,
-        ShouldReportDetailedTime(env, ioptions.statistics),
+        iter, tboptions.internal_comparator.user_comparator(), &merge,
+        kMaxSequenceNumber, &snapshots, earliest_write_conflict_snapshot,
+        snapshot_checker, env, ShouldReportDetailedTime(env, ioptions.stats),
        true /* internal key corruption is not ok */, range_del_agg.get(),
        blob_file_builder.get(), ioptions.allow_data_in_errors,
-        /*compaction=*/nullptr,
-        /*compaction_filter=*/nullptr, /*shutting_down=*/nullptr,
+        /*compaction=*/nullptr, compaction_filter.get(),
+        /*shutting_down=*/nullptr,
        /*preserve_deletes_seqnum=*/0, /*manual_compaction_paused=*/nullptr,
-        db_options.info_log, full_history_ts_low);
+        /*manual_compaction_canceled=*/nullptr, db_options.info_log,
+        full_history_ts_low);

    c_iter.SeekToFirst();
    for (; c_iter.Valid(); c_iter.Next()) {
@@ -199,6 +204,8 @@ Status BuildTable(
      const Slice& value = c_iter.value();
      const ParsedInternalKey& ikey = c_iter.ikey();
      // Generate a rolling 64-bit hash of the key and values
+      // Note :
+      // Here "key" integrates 'sequence_number'+'kType'+'user key'.
      s = output_validator.Add(key, value);
      if (!s.ok()) {
        break;
@@ -227,12 +234,17 @@ Status BuildTable(
        auto kv = tombstone.Serialize();
        builder->Add(kv.first.Encode(), kv.second);
        meta->UpdateBoundariesForRange(kv.first, tombstone.SerializeEndKey(),
-                                       tombstone.seq_, internal_comparator);
+                                       tombstone.seq_,
+                                       tboptions.internal_comparator);
      }
    }

    TEST_SYNC_POINT("BuildTable:BeforeFinishBuildTable");
    const bool empty = builder->IsEmpty();
+    if (num_input_entries != nullptr) {
+      *num_input_entries =
+          c_iter.num_input_entry_scanned() + num_unfragmented_tombstones;
+    }
    if (!s.ok() || empty) {
      builder->Abandon();
    } else {
@@ -248,6 +260,25 @@ Status BuildTable(
      meta->marked_for_compaction = builder->NeedCompact();
      assert(meta->fd.GetFileSize() > 0);
      tp = builder->GetTableProperties(); // refresh now that builder is finished
+      if (memtable_payload_bytes != nullptr &&
+          memtable_garbage_bytes != nullptr) {
+        const CompactionIterationStats& ci_stats = c_iter.iter_stats();
+        uint64_t total_payload_bytes = ci_stats.total_input_raw_key_bytes +
+                                       ci_stats.total_input_raw_value_bytes +
+                                       total_tombstone_payload_bytes;
+        uint64_t total_payload_bytes_written =
+            (tp.raw_key_size + tp.raw_value_size);
+        // Prevent underflow, which may still happen at this point
+        // since we only support inserts, deletes, and deleteRanges.
+        if (total_payload_bytes_written <= total_payload_bytes) {
+          *memtable_payload_bytes = total_payload_bytes;
+          *memtable_garbage_bytes =
+              total_payload_bytes - total_payload_bytes_written;
+        } else {
+          *memtable_payload_bytes = 0;
+          *memtable_garbage_bytes = 0;
+        }
+      }
      if (table_properties) {
        *table_properties = tp;
      }
@@ -257,7 +288,7 @@ Status BuildTable(
    // Finish and check for file errors
    TEST_SYNC_POINT("BuildTable:BeforeSyncTable");
    if (s.ok() && !empty) {
-      StopWatch sw(ioptions.clock, ioptions.statistics, TABLE_SYNC_MICROS);
+      StopWatch sw(ioptions.clock, ioptions.stats, TABLE_SYNC_MICROS);
      *io_status = file_writer->Sync(ioptions.use_fsync);
    }
    TEST_SYNC_POINT("BuildTable:BeforeCloseTableFile");
@@ -280,13 +311,14 @@ Status BuildTable(
      if (s.ok()) {
        s = blob_file_builder->Finish();
      } else {
-        blob_file_builder->Abandon();
+        blob_file_builder->Abandon(s);
      }
      blob_file_builder.reset();
    }

    // TODO Also check the IO status when create the Iterator.

+    TEST_SYNC_POINT("BuildTable:BeforeOutputValidation");
    if (s.ok() && !empty) {
      // Verify that the table is usable
      // We set for_compaction to false and don't OptimizeForCompactionTableRead
@@ -296,20 +328,20 @@ Status BuildTable(
      // to cache it here for further user reads
      ReadOptions read_options;
      std::unique_ptr<InternalIterator> it(table_cache->NewIterator(
-          read_options, file_options, internal_comparator, *meta,
-          nullptr /* range_del_agg */,
-          mutable_cf_options.prefix_extractor.get(), nullptr,
+          read_options, file_options, tboptions.internal_comparator, *meta,
+          nullptr /* range_del_agg */, mutable_cf_options.prefix_extractor,
+          nullptr,
          (internal_stats == nullptr) ? nullptr
                                      : internal_stats->GetFileReadHist(0),
          TableReaderCaller::kFlush, /*arena=*/nullptr,
-          /*skip_filter=*/false, level,
+          /*skip_filter=*/false, tboptions.level_at_creation,
          MaxFileSizeForL0MetaPin(mutable_cf_options),
          /*smallest_compaction_key=*/nullptr,
          /*largest_compaction_key*/ nullptr,
          /*allow_unprepared_value*/ false));
      s = it->status();
      if (s.ok() && paranoid_file_checks) {
-        OutputValidator file_validator(internal_comparator,
+        OutputValidator file_validator(tboptions.internal_comparator,
                                       /*enable_order_check=*/true,
                                       /*enable_hash=*/true);
        for (it->SeekToFirst(); it->Valid(); it->Next()) {
@@ -349,14 +381,19 @@ Status BuildTable(
    }
  }

+  Status status_for_listener = s;
  if (meta->fd.GetFileSize() == 0) {
    fname = "(nil)";
+    if (s.ok()) {
+      status_for_listener = Status::Aborted("Empty SST file not kept");
+    }
  }
  // Output to event logger and fire events.
  EventHelpers::LogAndNotifyTableFileCreationFinished(
-      event_logger, ioptions.listeners, dbname, column_family_name, fname,
-      job_id, meta->fd, meta->oldest_blob_file_number, tp, reason, s,
-      file_checksum, file_checksum_func_name);
+      event_logger, ioptions.listeners, dbname, tboptions.column_family_name,
+      fname, job_id, meta->fd, meta->oldest_blob_file_number, tp,
+      tboptions.reason, status_for_listener, file_checksum,
+      file_checksum_func_name);

  return s;
 }
@@ -24,37 +24,20 @@

 namespace ROCKSDB_NAMESPACE {

-struct Options;
 struct FileMetaData;

 class VersionSet;
-class Env;
-struct EnvOptions;
 class BlobFileAddition;
-class Iterator;
 class SnapshotChecker;
 class TableCache;
-class VersionEdit;
 class TableBuilder;
 class WritableFileWriter;
 class InternalStats;
 class BlobFileCompletionCallback;

-// @param column_family_name Name of the column family that is also identified
-//    by column_family_id, or empty string if unknown. It must outlive the
-//    TableBuilder returned by this function.
-TableBuilder* NewTableBuilder(
-    const ImmutableCFOptions& options, const MutableCFOptions& moptions,
-    const InternalKeyComparator& internal_comparator,
-    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-        int_tbl_prop_collector_factories,
-    uint32_t column_family_id, const std::string& column_family_name,
-    WritableFileWriter* file, const CompressionType compression_type,
-    const CompressionOptions& compression_opts, int level,
-    const bool skip_filters = false, const uint64_t creation_time = 0,
-    const uint64_t oldest_key_time = 0, const uint64_t target_file_size = 0,
-    const uint64_t file_creation_time = 0, const std::string& db_id = "",
-    const std::string& db_session_id = "");
+// Convenience function for NewTableBuilder on the embedded table_factory.
+TableBuilder* NewTableBuilder(const TableBuilderOptions& tboptions,
+                              WritableFileWriter* file);

 // Build a Table file from the contents of *iter.  The generated file
 // will be named according to number specified in meta. On success, the rest of
@@ -66,30 +49,26 @@ TableBuilder* NewTableBuilder(
 //    by column_family_id, or empty string if unknown.
 extern Status BuildTable(
    const std::string& dbname, VersionSet* versions,
-    const ImmutableDBOptions& db_options, const ImmutableCFOptions& options,
-    const MutableCFOptions& mutable_cf_options, const FileOptions& file_options,
-    TableCache* table_cache, InternalIterator* iter,
+    const ImmutableDBOptions& db_options, const TableBuilderOptions& tboptions,
+    const FileOptions& file_options, TableCache* table_cache,
+    InternalIterator* iter,
    std::vector<std::unique_ptr<FragmentedRangeTombstoneIterator>>
        range_del_iters,
    FileMetaData* meta, std::vector<BlobFileAddition>* blob_file_additions,
-    const InternalKeyComparator& internal_comparator,
-    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-        int_tbl_prop_collector_factories,
-    uint32_t column_family_id, const std::string& column_family_name,
    std::vector<SequenceNumber> snapshots,
    SequenceNumber earliest_write_conflict_snapshot,
-    SnapshotChecker* snapshot_checker, const CompressionType compression,
-    const CompressionOptions& compression_opts, bool paranoid_file_checks,
-    InternalStats* internal_stats, TableFileCreationReason reason,
-    IOStatus* io_status, const std::shared_ptr<IOTracer>& io_tracer,
+    SnapshotChecker* snapshot_checker, bool paranoid_file_checks,
+    InternalStats* internal_stats, IOStatus* io_status,
+    const std::shared_ptr<IOTracer>& io_tracer,
+    BlobFileCreationReason blob_creation_reason,
    EventLogger* event_logger = nullptr, int job_id = 0,
    const Env::IOPriority io_priority = Env::IO_HIGH,
-    TableProperties* table_properties = nullptr, int level = -1,
-    const uint64_t creation_time = 0, const uint64_t oldest_key_time = 0,
+    TableProperties* table_properties = nullptr,
    Env::WriteLifeTimeHint write_hint = Env::WLTH_NOT_SET,
-    const uint64_t file_creation_time = 0, const std::string& db_id = "",
-    const std::string& db_session_id = "",
    const std::string* full_history_ts_low = nullptr,
-    BlobFileCompletionCallback* blob_callback = nullptr);
+    BlobFileCompletionCallback* blob_callback = nullptr,
+    uint64_t* num_input_entries = nullptr,
+    uint64_t* memtable_payload_bytes = nullptr,
+    uint64_t* memtable_garbage_bytes = nullptr);

 }  // namespace ROCKSDB_NAMESPACE
@@ -35,19 +35,20 @@
 #include "rocksdb/status.h"
 #include "rocksdb/table.h"
 #include "rocksdb/universal_compaction.h"
-#include "rocksdb/utilities/backupable_db.h"
+#include "rocksdb/utilities/backup_engine.h"
 #include "rocksdb/utilities/checkpoint.h"
 #include "rocksdb/utilities/db_ttl.h"
 #include "rocksdb/utilities/memory_util.h"
 #include "rocksdb/utilities/optimistic_transaction_db.h"
+#include "rocksdb/utilities/table_properties_collectors.h"
 #include "rocksdb/utilities/transaction.h"
 #include "rocksdb/utilities/transaction_db.h"
 #include "rocksdb/utilities/write_batch_with_index.h"
 #include "rocksdb/write_batch.h"
 #include "utilities/merge_operators.h"

-using ROCKSDB_NAMESPACE::BackupableDBOptions;
 using ROCKSDB_NAMESPACE::BackupEngine;
+using ROCKSDB_NAMESPACE::BackupEngineOptions;
 using ROCKSDB_NAMESPACE::BackupID;
 using ROCKSDB_NAMESPACE::BackupInfo;
 using ROCKSDB_NAMESPACE::BatchResult;
@@ -84,8 +85,10 @@ using ROCKSDB_NAMESPACE::MemoryAllocator;
 using ROCKSDB_NAMESPACE::MemoryUtil;
 using ROCKSDB_NAMESPACE::MergeOperator;
 using ROCKSDB_NAMESPACE::NewBloomFilterPolicy;
+using ROCKSDB_NAMESPACE::NewCompactOnDeletionCollectorFactory;
 using ROCKSDB_NAMESPACE::NewGenericRateLimiter;
 using ROCKSDB_NAMESPACE::NewLRUCache;
+using ROCKSDB_NAMESPACE::NewRibbonFilterPolicy;
 using ROCKSDB_NAMESPACE::OptimisticTransactionDB;
 using ROCKSDB_NAMESPACE::OptimisticTransactionOptions;
 using ROCKSDB_NAMESPACE::Options;
@@ -104,6 +107,7 @@ using ROCKSDB_NAMESPACE::SliceTransform;
 using ROCKSDB_NAMESPACE::Snapshot;
 using ROCKSDB_NAMESPACE::SstFileWriter;
 using ROCKSDB_NAMESPACE::Status;
+using ROCKSDB_NAMESPACE::TablePropertiesCollectorFactory;
 using ROCKSDB_NAMESPACE::Transaction;
 using ROCKSDB_NAMESPACE::TransactionDB;
 using ROCKSDB_NAMESPACE::TransactionDBOptions;
@@ -185,8 +189,8 @@ struct rocksdb_transaction_options_t {
 struct rocksdb_transaction_t {
  Transaction* rep;
 };
-struct rocksdb_backupable_db_options_t {
-  BackupableDBOptions rep;
+struct rocksdb_backup_engine_options_t {
+  BackupEngineOptions rep;
 };
 struct rocksdb_checkpoint_t {
  Checkpoint* rep;
@@ -286,45 +290,10 @@ struct rocksdb_filterpolicy_t : public FilterPolicy {
  void* state_;
  void (*destructor_)(void*);
  const char* (*name_)(void*);
-  char* (*create_)(
-      void*,
-      const char* const* key_array, const size_t* key_length_array,
-      int num_keys,
-      size_t* filter_length);
-  unsigned char (*key_match_)(
-      void*,
-      const char* key, size_t length,
-      const char* filter, size_t filter_length);
-  void (*delete_filter_)(
-      void*,
-      const char* filter, size_t filter_length);

  ~rocksdb_filterpolicy_t() override { (*destructor_)(state_); }

  const char* Name() const override { return (*name_)(state_); }
-
-  void CreateFilter(const Slice* keys, int n, std::string* dst) const override {
-    std::vector<const char*> key_pointers(n);
-    std::vector<size_t> key_sizes(n);
-    for (int i = 0; i < n; i++) {
-      key_pointers[i] = keys[i].data();
-      key_sizes[i] = keys[i].size();
-    }
-    size_t len;
-    char* filter = (*create_)(state_, &key_pointers[0], &key_sizes[0], n, &len);
-    dst->append(filter, len);
-
-    if (delete_filter_ != nullptr) {
-      (*delete_filter_)(state_, filter, len);
-    } else {
-      free(filter);
-    }
-  }
-
-  bool KeyMayMatch(const Slice& key, const Slice& filter) const override {
-    return (*key_match_)(state_, key.data(), key.size(),
-                         filter.data(), filter.size());
-  }
 };

 struct rocksdb_mergeoperator_t : public MergeOperator {
@@ -543,12 +512,11 @@ rocksdb_t* rocksdb_open_as_secondary(const rocksdb_options_t* options,
 rocksdb_backup_engine_t* rocksdb_backup_engine_open(
    const rocksdb_options_t* options, const char* path, char** errptr) {
  BackupEngine* be;
-  if (SaveError(errptr, BackupEngine::Open(options->rep.env,
-                                           BackupableDBOptions(path,
-                                                               nullptr,
-                                                               true,
-                                                               options->rep.info_log.get()),
-                                           &be))) {
+  if (SaveError(errptr, BackupEngine::Open(
+                            options->rep.env,
+                            BackupEngineOptions(path, nullptr, true,
+                                                options->rep.info_log.get()),
+                            &be))) {
    return nullptr;
  }
  rocksdb_backup_engine_t* result = new rocksdb_backup_engine_t;
@@ -557,7 +525,7 @@ rocksdb_backup_engine_t* rocksdb_backup_engine_open(
 }

 rocksdb_backup_engine_t* rocksdb_backup_engine_open_opts(
-    const rocksdb_backupable_db_options_t* options, rocksdb_env_t* env,
+    const rocksdb_backup_engine_options_t* options, rocksdb_env_t* env,
    char** errptr) {
  BackupEngine* be;
  if (SaveError(errptr, BackupEngine::Open(options->rep, env->rep, &be))) {
@@ -664,125 +632,125 @@ void rocksdb_backup_engine_close(rocksdb_backup_engine_t* be) {
  delete be;
 }

-rocksdb_backupable_db_options_t* rocksdb_backupable_db_options_create(
+rocksdb_backup_engine_options_t* rocksdb_backup_engine_options_create(
    const char* backup_dir) {
-  return new rocksdb_backupable_db_options_t{
-      BackupableDBOptions(std::string(backup_dir))};
+  return new rocksdb_backup_engine_options_t{
+      BackupEngineOptions(std::string(backup_dir))};
 }

-void rocksdb_backupable_db_options_set_backup_dir(
-    rocksdb_backupable_db_options_t* options, const char* backup_dir) {
+void rocksdb_backup_engine_options_set_backup_dir(
+    rocksdb_backup_engine_options_t* options, const char* backup_dir) {
  options->rep.backup_dir = std::string(backup_dir);
 }

-void rocksdb_backupable_db_options_set_env(
-    rocksdb_backupable_db_options_t* options, rocksdb_env_t* env) {
+void rocksdb_backup_engine_options_set_env(
+    rocksdb_backup_engine_options_t* options, rocksdb_env_t* env) {
  options->rep.backup_env = (env ? env->rep : nullptr);
 }

-void rocksdb_backupable_db_options_set_share_table_files(
-    rocksdb_backupable_db_options_t* options, unsigned char val) {
+void rocksdb_backup_engine_options_set_share_table_files(
+    rocksdb_backup_engine_options_t* options, unsigned char val) {
  options->rep.share_table_files = val;
 }

-unsigned char rocksdb_backupable_db_options_get_share_table_files(
-    rocksdb_backupable_db_options_t* options) {
+unsigned char rocksdb_backup_engine_options_get_share_table_files(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.share_table_files;
 }

-void rocksdb_backupable_db_options_set_sync(
-    rocksdb_backupable_db_options_t* options, unsigned char val) {
+void rocksdb_backup_engine_options_set_sync(
+    rocksdb_backup_engine_options_t* options, unsigned char val) {
  options->rep.sync = val;
 }

-unsigned char rocksdb_backupable_db_options_get_sync(
-    rocksdb_backupable_db_options_t* options) {
+unsigned char rocksdb_backup_engine_options_get_sync(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.sync;
 }

-void rocksdb_backupable_db_options_set_destroy_old_data(
-    rocksdb_backupable_db_options_t* options, unsigned char val) {
+void rocksdb_backup_engine_options_set_destroy_old_data(
+    rocksdb_backup_engine_options_t* options, unsigned char val) {
  options->rep.destroy_old_data = val;
 }

-unsigned char rocksdb_backupable_db_options_get_destroy_old_data(
-    rocksdb_backupable_db_options_t* options) {
+unsigned char rocksdb_backup_engine_options_get_destroy_old_data(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.destroy_old_data;
 }

-void rocksdb_backupable_db_options_set_backup_log_files(
-    rocksdb_backupable_db_options_t* options, unsigned char val) {
+void rocksdb_backup_engine_options_set_backup_log_files(
+    rocksdb_backup_engine_options_t* options, unsigned char val) {
  options->rep.backup_log_files = val;
 }

-unsigned char rocksdb_backupable_db_options_get_backup_log_files(
-    rocksdb_backupable_db_options_t* options) {
+unsigned char rocksdb_backup_engine_options_get_backup_log_files(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.backup_log_files;
 }

-void rocksdb_backupable_db_options_set_backup_rate_limit(
-    rocksdb_backupable_db_options_t* options, uint64_t limit) {
+void rocksdb_backup_engine_options_set_backup_rate_limit(
+    rocksdb_backup_engine_options_t* options, uint64_t limit) {
  options->rep.backup_rate_limit = limit;
 }

-uint64_t rocksdb_backupable_db_options_get_backup_rate_limit(
-    rocksdb_backupable_db_options_t* options) {
+uint64_t rocksdb_backup_engine_options_get_backup_rate_limit(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.backup_rate_limit;
 }

-void rocksdb_backupable_db_options_set_restore_rate_limit(
-    rocksdb_backupable_db_options_t* options, uint64_t limit) {
+void rocksdb_backup_engine_options_set_restore_rate_limit(
+    rocksdb_backup_engine_options_t* options, uint64_t limit) {
  options->rep.restore_rate_limit = limit;
 }

-uint64_t rocksdb_backupable_db_options_get_restore_rate_limit(
-    rocksdb_backupable_db_options_t* options) {
+uint64_t rocksdb_backup_engine_options_get_restore_rate_limit(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.restore_rate_limit;
 }

-void rocksdb_backupable_db_options_set_max_background_operations(
-    rocksdb_backupable_db_options_t* options, int val) {
+void rocksdb_backup_engine_options_set_max_background_operations(
+    rocksdb_backup_engine_options_t* options, int val) {
  options->rep.max_background_operations = val;
 }

-int rocksdb_backupable_db_options_get_max_background_operations(
-    rocksdb_backupable_db_options_t* options) {
+int rocksdb_backup_engine_options_get_max_background_operations(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.max_background_operations;
 }

-void rocksdb_backupable_db_options_set_callback_trigger_interval_size(
-    rocksdb_backupable_db_options_t* options, uint64_t size) {
+void rocksdb_backup_engine_options_set_callback_trigger_interval_size(
+    rocksdb_backup_engine_options_t* options, uint64_t size) {
  options->rep.callback_trigger_interval_size = size;
 }

-uint64_t rocksdb_backupable_db_options_get_callback_trigger_interval_size(
-    rocksdb_backupable_db_options_t* options) {
+uint64_t rocksdb_backup_engine_options_get_callback_trigger_interval_size(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.callback_trigger_interval_size;
 }

-void rocksdb_backupable_db_options_set_max_valid_backups_to_open(
-    rocksdb_backupable_db_options_t* options, int val) {
+void rocksdb_backup_engine_options_set_max_valid_backups_to_open(
+    rocksdb_backup_engine_options_t* options, int val) {
  options->rep.max_valid_backups_to_open = val;
 }

-int rocksdb_backupable_db_options_get_max_valid_backups_to_open(
-    rocksdb_backupable_db_options_t* options) {
+int rocksdb_backup_engine_options_get_max_valid_backups_to_open(
+    rocksdb_backup_engine_options_t* options) {
  return options->rep.max_valid_backups_to_open;
 }

-void rocksdb_backupable_db_options_set_share_files_with_checksum_naming(
-    rocksdb_backupable_db_options_t* options, int val) {
+void rocksdb_backup_engine_options_set_share_files_with_checksum_naming(
+    rocksdb_backup_engine_options_t* options, int val) {
  options->rep.share_files_with_checksum_naming =
-      static_cast<BackupableDBOptions::ShareFilesNaming>(val);
+      static_cast<BackupEngineOptions::ShareFilesNaming>(val);
 }

-int rocksdb_backupable_db_options_get_share_files_with_checksum_naming(
-    rocksdb_backupable_db_options_t* options) {
+int rocksdb_backup_engine_options_get_share_files_with_checksum_naming(
+    rocksdb_backup_engine_options_t* options) {
  return static_cast<int>(options->rep.share_files_with_checksum_naming);
 }

-void rocksdb_backupable_db_options_destroy(
-    rocksdb_backupable_db_options_t* options) {
+void rocksdb_backup_engine_options_destroy(
+    rocksdb_backup_engine_options_t* options) {
  delete options;
 }

@@ -1509,6 +1477,10 @@ void rocksdb_flush_cf(
  SaveError(errptr, db->rep->Flush(options->rep, column_family->rep));
 }

+void rocksdb_flush_wal(rocksdb_t* db, unsigned char sync, char** errptr) {
+  SaveError(errptr, db->rep->FlushWAL(sync));
+}
+
 void rocksdb_disable_file_deletions(
    rocksdb_t* db,
    char** errptr) {
@@ -2325,11 +2297,6 @@ void rocksdb_block_based_options_set_data_block_hash_ratio(
  options->rep.data_block_hash_table_util_ratio = v;
 }

-void rocksdb_block_based_options_set_hash_index_allow_collision(
-    rocksdb_block_based_table_options_t* options, unsigned char v) {
-  options->rep.hash_index_allow_collision = v;
-}
-
 void rocksdb_block_based_options_set_cache_index_and_filter_blocks(
    rocksdb_block_based_table_options_t* options, unsigned char v) {
  options->rep.cache_index_and_filter_blocks = v;
@@ -2743,6 +2710,25 @@ double rocksdb_options_get_blob_gc_age_cutoff(rocksdb_options_t* opt) {
  return opt->rep.blob_garbage_collection_age_cutoff;
 }

+void rocksdb_options_set_blob_gc_force_threshold(rocksdb_options_t* opt,
+                                                 double val) {
+  opt->rep.blob_garbage_collection_force_threshold = val;
+}
+
+double rocksdb_options_get_blob_gc_force_threshold(rocksdb_options_t* opt) {
+  return opt->rep.blob_garbage_collection_force_threshold;
+}
+
+void rocksdb_options_set_blob_compaction_readahead_size(rocksdb_options_t* opt,
+                                                        uint64_t val) {
+  opt->rep.blob_compaction_readahead_size = val;
+}
+
+uint64_t rocksdb_options_get_blob_compaction_readahead_size(
+    rocksdb_options_t* opt) {
+  return opt->rep.blob_compaction_readahead_size;
+}
+
 void rocksdb_options_set_num_levels(rocksdb_options_t* opt, int n) {
  opt->rep.num_levels = n;
 }
@@ -2779,9 +2765,6 @@ int rocksdb_options_get_level0_stop_writes_trigger(rocksdb_options_t* opt) {
  return opt->rep.level0_stop_writes_trigger;
 }

-void rocksdb_options_set_max_mem_compaction_level(rocksdb_options_t* /*opt*/,
-                                                  int /*n*/) {}
-
 void rocksdb_options_set_wal_recovery_mode(rocksdb_options_t* opt,int mode) {
  opt->rep.wal_recovery_mode = static_cast<WALRecoveryMode>(mode);
 }
@@ -2807,7 +2790,7 @@ int rocksdb_options_get_bottommost_compression(rocksdb_options_t* opt) {
 }

 void rocksdb_options_set_compression_per_level(rocksdb_options_t* opt,
-                                               int* level_values,
+                                               const int* level_values,
                                               size_t num_levels) {
  opt->rep.compression_per_level.resize(num_levels);
  for (size_t i = 0; i < num_levels; ++i) {
@@ -2857,11 +2840,31 @@ void rocksdb_options_set_compression_options_zstd_max_train_bytes(
  opt->rep.compression_opts.zstd_max_train_bytes = zstd_max_train_bytes;
 }

+int rocksdb_options_get_compression_options_zstd_max_train_bytes(
+    rocksdb_options_t* opt) {
+  return opt->rep.compression_opts.zstd_max_train_bytes;
+}
+
+void rocksdb_options_set_compression_options_parallel_threads(
+    rocksdb_options_t* opt, int value) {
+  opt->rep.compression_opts.parallel_threads = value;
+}
+
+int rocksdb_options_get_compression_options_parallel_threads(
+    rocksdb_options_t* opt) {
+  return opt->rep.compression_opts.parallel_threads;
+}
+
 void rocksdb_options_set_compression_options_max_dict_buffer_bytes(
    rocksdb_options_t* opt, uint64_t max_dict_buffer_bytes) {
  opt->rep.compression_opts.max_dict_buffer_bytes = max_dict_buffer_bytes;
 }

+uint64_t rocksdb_options_get_compression_options_max_dict_buffer_bytes(
+    rocksdb_options_t* opt) {
+  return opt->rep.compression_opts.max_dict_buffer_bytes;
+}
+
 void rocksdb_options_set_prefix_extractor(
    rocksdb_options_t* opt, rocksdb_slicetransform_t* prefix_extractor) {
  opt->rep.prefix_extractor.reset(prefix_extractor);
@@ -2912,10 +2915,6 @@ size_t rocksdb_options_get_manifest_preallocation_size(rocksdb_options_t* opt) {
  return opt->rep.manifest_preallocation_size;
 }

-// noop
-void rocksdb_options_set_purge_redundant_kvs_while_flush(
-    rocksdb_options_t* /*opt*/, unsigned char /*v*/) {}
-
 void rocksdb_options_set_use_direct_reads(rocksdb_options_t* opt,
                                          unsigned char v) {
  opt->rep.use_direct_reads = v;
@@ -2962,16 +2961,6 @@ unsigned char rocksdb_options_get_is_fd_close_on_exec(rocksdb_options_t* opt) {
  return opt->rep.is_fd_close_on_exec;
 }

-void rocksdb_options_set_skip_log_error_on_recovery(
-    rocksdb_options_t* opt, unsigned char v) {
-  opt->rep.skip_log_error_on_recovery = v;
-}
-
-unsigned char rocksdb_options_get_skip_log_error_on_recovery(
-    rocksdb_options_t* opt) {
-  return opt->rep.skip_log_error_on_recovery;
-}
-
 void rocksdb_options_set_stats_dump_period_sec(
    rocksdb_options_t* opt, unsigned int v) {
  opt->rep.stats_dump_period_sec = v;
@@ -3001,6 +2990,11 @@ unsigned char rocksdb_options_get_advise_random_on_open(
  return opt->rep.advise_random_on_open;
 }

+void rocksdb_options_set_experimental_mempurge_threshold(rocksdb_options_t* opt,
+                                                         double v) {
+  opt->rep.experimental_mempurge_threshold = v;
+}
+
 void rocksdb_options_set_access_hint_on_compaction_start(
    rocksdb_options_t* opt, int v) {
  switch(v) {
@@ -3178,15 +3172,6 @@ int rocksdb_options_get_max_background_compactions(rocksdb_options_t* opt) {
  return opt->rep.max_background_compactions;
 }

-void rocksdb_options_set_base_background_compactions(rocksdb_options_t* opt,
-                                                     int n) {
-  opt->rep.base_background_compactions = n;
-}
-
-int rocksdb_options_get_base_background_compactions(rocksdb_options_t* opt) {
-  return opt->rep.base_background_compactions;
-}
-
 void rocksdb_options_set_max_background_flushes(rocksdb_options_t* opt, int n) {
  opt->rep.max_background_flushes = n;
 }
@@ -3228,22 +3213,6 @@ size_t rocksdb_options_get_recycle_log_file_num(rocksdb_options_t* opt) {
  return opt->rep.recycle_log_file_num;
 }

-void rocksdb_options_set_soft_rate_limit(rocksdb_options_t* opt, double v) {
-  opt->rep.soft_rate_limit = v;
-}
-
-double rocksdb_options_get_soft_rate_limit(rocksdb_options_t* opt) {
-  return opt->rep.soft_rate_limit;
-}
-
-void rocksdb_options_set_hard_rate_limit(rocksdb_options_t* opt, double v) {
-  opt->rep.hard_rate_limit = v;
-}
-
-double rocksdb_options_get_hard_rate_limit(rocksdb_options_t* opt) {
-  return opt->rep.hard_rate_limit;
-}
-
 void rocksdb_options_set_soft_pending_compaction_bytes_limit(rocksdb_options_t* opt, size_t v) {
  opt->rep.soft_pending_compaction_bytes_limit = v;
 }
@@ -3262,16 +3231,6 @@ size_t rocksdb_options_get_hard_pending_compaction_bytes_limit(
  return opt->rep.hard_pending_compaction_bytes_limit;
 }

-void rocksdb_options_set_rate_limit_delay_max_milliseconds(
-    rocksdb_options_t* opt, unsigned int v) {
-  opt->rep.rate_limit_delay_max_milliseconds = v;
-}
-
-unsigned int rocksdb_options_get_rate_limit_delay_max_milliseconds(
-    rocksdb_options_t* opt) {
-  return opt->rep.rate_limit_delay_max_milliseconds;
-}
-
 void rocksdb_options_set_max_manifest_file_size(
    rocksdb_options_t* opt, size_t v) {
  opt->rep.max_manifest_file_size = v;
@@ -3290,11 +3249,6 @@ int rocksdb_options_get_table_cache_numshardbits(rocksdb_options_t* opt) {
  return opt->rep.table_cache_numshardbits;
 }

-void rocksdb_options_set_table_cache_remove_scan_count_limit(
-    rocksdb_options_t* /*opt*/, int /*v*/) {
-  // this option is deprecated
-}
-
 void rocksdb_options_set_arena_block_size(
    rocksdb_options_t* opt, size_t v) {
  opt->rep.arena_block_size = v;
@@ -3476,6 +3430,23 @@ unsigned char rocksdb_options_get_atomic_flush(rocksdb_options_t* opt) {
  return opt->rep.atomic_flush;
 }

+void rocksdb_options_set_manual_wal_flush(rocksdb_options_t* opt,
+                                          unsigned char manual_wal_flush) {
+  opt->rep.manual_wal_flush = manual_wal_flush;
+}
+
+unsigned char rocksdb_options_get_manual_wal_flush(rocksdb_options_t* opt) {
+  return opt->rep.manual_wal_flush;
+}
+
+void rocksdb_options_set_wal_compression(rocksdb_options_t* opt, int val) {
+  opt->rep.wal_compression = static_cast<CompressionType>(val);
+}
+
+int rocksdb_options_get_wal_compression(rocksdb_options_t* opt) {
+  return opt->rep.wal_compression;
+}
+
 rocksdb_ratelimiter_t* rocksdb_ratelimiter_create(
    int64_t rate_bytes_per_sec,
    int64_t refill_period_us,
@@ -3497,6 +3468,14 @@ void rocksdb_options_set_row_cache(rocksdb_options_t* opt, rocksdb_cache_t* cach
  }
 }

+void rocksdb_options_add_compact_on_deletion_collector_factory(
+    rocksdb_options_t* opt, size_t window_size, size_t num_dels_trigger) {
+  std::shared_ptr<ROCKSDB_NAMESPACE::TablePropertiesCollectorFactory>
+      compact_on_del =
+          NewCompactOnDeletionCollectorFactory(window_size, num_dels_trigger);
+  opt->rep.table_properties_collector_factories.emplace_back(compact_on_del);
+}
+
 void rocksdb_set_perf_level(int v) {
  PerfLevel level = static_cast<PerfLevel>(v);
  SetPerfLevel(level);
@@ -3760,37 +3739,12 @@ void rocksdb_comparator_destroy(rocksdb_comparator_t* cmp) {
  delete cmp;
 }

-rocksdb_filterpolicy_t* rocksdb_filterpolicy_create(
-    void* state,
-    void (*destructor)(void*),
-    char* (*create_filter)(
-        void*,
-        const char* const* key_array, const size_t* key_length_array,
-        int num_keys,
-        size_t* filter_length),
-    unsigned char (*key_may_match)(
-        void*,
-        const char* key, size_t length,
-        const char* filter, size_t filter_length),
-    void (*delete_filter)(
-        void*,
-        const char* filter, size_t filter_length),
-    const char* (*name)(void*)) {
-  rocksdb_filterpolicy_t* result = new rocksdb_filterpolicy_t;
-  result->state_ = state;
-  result->destructor_ = destructor;
-  result->create_ = create_filter;
-  result->key_match_ = key_may_match;
-  result->delete_filter_ = delete_filter;
-  result->name_ = name;
-  return result;
-}
-
 void rocksdb_filterpolicy_destroy(rocksdb_filterpolicy_t* filter) {
  delete filter;
 }

-rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_format(int bits_per_key, bool original_format) {
+rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_format(
+    double bits_per_key, bool original_format) {
  // Make a rocksdb_filterpolicy_t, but override all of its methods so
  // they delegate to a NewBloomFilterPolicy() instead of user
  // supplied C functions.
@@ -3798,12 +3752,8 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_format(int bits_per_ke
    const FilterPolicy* rep_;
    ~Wrapper() override { delete rep_; }
    const char* Name() const override { return rep_->Name(); }
-    void CreateFilter(const Slice* keys, int n,
-                      std::string* dst) const override {
-      return rep_->CreateFilter(keys, n, dst);
-    }
-    bool KeyMayMatch(const Slice& key, const Slice& filter) const override {
-      return rep_->KeyMayMatch(key, filter);
+    const char* CompatibilityName() const override {
+      return rep_->CompatibilityName();
    }
    // No need to override GetFilterBitsBuilder if this one is overridden
    ROCKSDB_NAMESPACE::FilterBitsBuilder* GetBuilderWithContext(
@@ -3820,19 +3770,62 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_format(int bits_per_ke
  Wrapper* wrapper = new Wrapper;
  wrapper->rep_ = NewBloomFilterPolicy(bits_per_key, original_format);
  wrapper->state_ = nullptr;
-  wrapper->delete_filter_ = nullptr;
  wrapper->destructor_ = &Wrapper::DoNothing;
  return wrapper;
 }

-rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_full(int bits_per_key) {
+rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_full(
+    double bits_per_key) {
  return rocksdb_filterpolicy_create_bloom_format(bits_per_key, false);
 }

-rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom(int bits_per_key) {
+rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom(double bits_per_key) {
  return rocksdb_filterpolicy_create_bloom_format(bits_per_key, true);
 }

+rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_ribbon_format(
+    double bloom_equivalent_bits_per_key, int bloom_before_level) {
+  // Make a rocksdb_filterpolicy_t, but override all of its methods so
+  // they delegate to a NewRibbonFilterPolicy() instead of user
+  // supplied C functions.
+  struct Wrapper : public rocksdb_filterpolicy_t {
+    const FilterPolicy* rep_;
+    ~Wrapper() override { delete rep_; }
+    const char* Name() const override { return rep_->Name(); }
+    const char* CompatibilityName() const override {
+      return rep_->CompatibilityName();
+    }
+    ROCKSDB_NAMESPACE::FilterBitsBuilder* GetBuilderWithContext(
+        const ROCKSDB_NAMESPACE::FilterBuildingContext& context)
+        const override {
+      return rep_->GetBuilderWithContext(context);
+    }
+    ROCKSDB_NAMESPACE::FilterBitsReader* GetFilterBitsReader(
+        const Slice& contents) const override {
+      return rep_->GetFilterBitsReader(contents);
+    }
+    static void DoNothing(void*) {}
+  };
+  Wrapper* wrapper = new Wrapper;
+  wrapper->rep_ =
+      NewRibbonFilterPolicy(bloom_equivalent_bits_per_key, bloom_before_level);
+  wrapper->state_ = nullptr;
+  wrapper->destructor_ = &Wrapper::DoNothing;
+  return wrapper;
+}
+
+rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_ribbon(
+    double bloom_equivalent_bits_per_key) {
+  return rocksdb_filterpolicy_create_ribbon_format(
+      bloom_equivalent_bits_per_key, /*bloom_before_level = disabled*/ -1);
+}
+
+rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_ribbon_hybrid(
+    double bloom_equivalent_bits_per_key, int bloom_before_level) {
+  return rocksdb_filterpolicy_create_ribbon_format(
+      bloom_equivalent_bits_per_key, bloom_before_level);
+}
+
 rocksdb_mergeoperator_t* rocksdb_mergeoperator_create(
    void* state, void (*destructor)(void*),
    char* (*full_merge)(void*, const char* key, size_t key_length,
@@ -4329,6 +4322,11 @@ rocksdb_sstfilewriter_t* rocksdb_sstfilewriter_create(
  return writer;
 }

+void rocksdb_create_dir_if_missing(rocksdb_env_t* env, const char* path,
+                                   char** errptr) {
+  SaveError(errptr, env->rep->CreateDirIfMissing(std::string(path)));
+}
+
 rocksdb_sstfilewriter_t* rocksdb_sstfilewriter_create_with_comparator(
    const rocksdb_envoptions_t* env, const rocksdb_options_t* io_options,
    const rocksdb_comparator_t* /*comparator*/) {
@@ -4476,10 +4474,11 @@ void rocksdb_slicetransform_destroy(rocksdb_slicetransform_t* st) {
  delete st;
 }

-struct Wrapper : public rocksdb_slicetransform_t {
+struct SliceTransformWrapper : public rocksdb_slicetransform_t {
  const SliceTransform* rep_;
-  ~Wrapper() override { delete rep_; }
+  ~SliceTransformWrapper() override { delete rep_; }
  const char* Name() const override { return rep_->Name(); }
+  std::string GetId() const override { return rep_->GetId(); }
  Slice Transform(const Slice& src) const override {
    return rep_->Transform(src);
  }
@@ -4491,18 +4490,18 @@ struct Wrapper : public rocksdb_slicetransform_t {
 };

 rocksdb_slicetransform_t* rocksdb_slicetransform_create_fixed_prefix(size_t prefixLen) {
-  Wrapper* wrapper = new Wrapper;
+  SliceTransformWrapper* wrapper = new SliceTransformWrapper;
  wrapper->rep_ = ROCKSDB_NAMESPACE::NewFixedPrefixTransform(prefixLen);
  wrapper->state_ = nullptr;
-  wrapper->destructor_ = &Wrapper::DoNothing;
+  wrapper->destructor_ = &SliceTransformWrapper::DoNothing;
  return wrapper;
 }

 rocksdb_slicetransform_t* rocksdb_slicetransform_create_noop() {
-  Wrapper* wrapper = new Wrapper;
+  SliceTransformWrapper* wrapper = new SliceTransformWrapper;
  wrapper->rep_ = ROCKSDB_NAMESPACE::NewNoopTransform();
  wrapper->state_ = nullptr;
-  wrapper->destructor_ = &Wrapper::DoNothing;
+  wrapper->destructor_ = &SliceTransformWrapper::DoNothing;
  return wrapper;
 }

@@ -4618,6 +4617,11 @@ int rocksdb_livefiles_count(
  return static_cast<int>(lf->rep.size());
 }

+const char* rocksdb_livefiles_column_family_name(const rocksdb_livefiles_t* lf,
+                                                 int index) {
+  return lf->rep[index].column_family_name.c_str();
+}
+
 const char* rocksdb_livefiles_name(
  const rocksdb_livefiles_t* lf,
  int index) {
@@ -4784,6 +4788,27 @@ void rocksdb_optimistictransaction_options_set_set_snapshot(
  opt->rep.set_snapshot = v;
 }

+char* rocksdb_optimistictransactiondb_property_value(
+    rocksdb_optimistictransactiondb_t* db, const char* propname) {
+  std::string tmp;
+  if (db->rep->GetProperty(Slice(propname), &tmp)) {
+    // We use strdup() since we expect human readable output.
+    return strdup(tmp.c_str());
+  } else {
+    return nullptr;
+  }
+}
+
+int rocksdb_optimistictransactiondb_property_int(
+    rocksdb_optimistictransactiondb_t* db, const char* propname,
+    uint64_t* out_val) {
+  if (db->rep->GetIntProperty(Slice(propname), out_val)) {
+    return 0;
+  } else {
+    return -1;
+  }
+}
+
 rocksdb_column_family_handle_t* rocksdb_transactiondb_create_column_family(
    rocksdb_transactiondb_t* txn_db,
    const rocksdb_options_t* column_family_options,
@@ -4854,6 +4879,27 @@ void rocksdb_transactiondb_release_snapshot(
  delete snapshot;
 }

+char* rocksdb_transactiondb_property_value(rocksdb_transactiondb_t* db,
+                                           const char* propname) {
+  std::string tmp;
+  if (db->rep->GetProperty(Slice(propname), &tmp)) {
+    // We use strdup() since we expect human readable output.
+    return strdup(tmp.c_str());
+  } else {
+    return nullptr;
+  }
+}
+
+int rocksdb_transactiondb_property_int(rocksdb_transactiondb_t* db,
+                                       const char* propname,
+                                       uint64_t* out_val) {
+  if (db->rep->GetIntProperty(Slice(propname), out_val)) {
+    return 0;
+  } else {
+    return -1;
+  }
+}
+
 rocksdb_transaction_t* rocksdb_transaction_begin(
    rocksdb_transactiondb_t* txn_db,
    const rocksdb_writeoptions_t* write_options,
@@ -5256,12 +5302,31 @@ rocksdb_transaction_t* rocksdb_optimistictransaction_begin(
  return old_txn;
 }

+// Write batch into OptimisticTransactionDB
+void rocksdb_optimistictransactiondb_write(
+    rocksdb_optimistictransactiondb_t* otxn_db,
+    const rocksdb_writeoptions_t* options, rocksdb_writebatch_t* batch,
+    char** errptr) {
+  SaveError(errptr, otxn_db->rep->Write(options->rep, &batch->rep));
+}
+
 void rocksdb_optimistictransactiondb_close(
    rocksdb_optimistictransactiondb_t* otxn_db) {
  delete otxn_db->rep;
  delete otxn_db;
 }

+rocksdb_checkpoint_t* rocksdb_optimistictransactiondb_checkpoint_object_create(
+    rocksdb_optimistictransactiondb_t* otxn_db, char** errptr) {
+  Checkpoint* checkpoint;
+  if (SaveError(errptr, Checkpoint::Create(otxn_db->rep, &checkpoint))) {
+    return nullptr;
+  }
+  rocksdb_checkpoint_t* result = new rocksdb_checkpoint_t;
+  result->rep = checkpoint;
+  return result;
+}
+
 void rocksdb_free(void* ptr) { free(ptr); }

 rocksdb_pinnableslice_t* rocksdb_get_pinned(
@@ -7,12 +7,13 @@

 #ifndef ROCKSDB_LITE  // Lite does not support C API

-#include "rocksdb/c.h"
-
+#include <assert.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+
+#include "rocksdb/c.h"
 #ifndef OS_WIN
 #include <unistd.h>
 #endif
@@ -89,10 +90,8 @@ static void CheckEqual(const char* expected, const char* v, size_t n) {
    // ok
    return;
  } else {
-    fprintf(stderr, "%s: expected '%s', got '%s'\n",
-            phase,
-            (expected ? expected : "(null)"),
-            (v ? v : "(null"));
+    fprintf(stderr, "%s: expected '%s', got '%s'\n", phase,
+            (expected ? expected : "(null)"), (v ? v : "(null)"));
    abort();
  }
 }
@@ -226,39 +225,6 @@ static const char* CmpName(void* arg) {
  return "foo";
 }

-// Custom filter policy
-static unsigned char fake_filter_result = 1;
-static void FilterDestroy(void* arg) { (void)arg; }
-static const char* FilterName(void* arg) {
-  (void)arg;
-  return "TestFilter";
-}
-static char* FilterCreate(
-    void* arg,
-    const char* const* key_array, const size_t* key_length_array,
-    int num_keys,
-    size_t* filter_length) {
-  (void)arg;
-  (void)key_array;
-  (void)key_length_array;
-  (void)num_keys;
-  *filter_length = 4;
-  char* result = malloc(4);
-  memcpy(result, "fake", 4);
-  return result;
-}
-static unsigned char FilterKeyMatch(
-    void* arg,
-    const char* key, size_t length,
-    const char* filter, size_t filter_length) {
-  (void)arg;
-  (void)key;
-  (void)length;
-  CheckCondition(filter_length == 4);
-  CheckCondition(memcmp(filter, "fake", 4) == 0);
-  return fake_filter_result;
-}
-
 // Custom compaction filter
 static void CFilterDestroy(void* arg) { (void)arg; }
 static const char* CFilterName(void* arg) {
@@ -480,6 +446,10 @@ int main(int argc, char** argv) {
  cmp = rocksdb_comparator_create(NULL, CmpDestroy, CmpCompare, CmpName);
  dbpath = rocksdb_dbpath_create(dbpathname, 1024 * 1024);
  env = rocksdb_create_default_env();
+
+  rocksdb_create_dir_if_missing(env, GetTempDir(), &err);
+  CheckNoError(err);
+
  cache = rocksdb_cache_create_lru(100000);

  options = rocksdb_options_create();
@@ -490,7 +460,6 @@ int main(int argc, char** argv) {
  rocksdb_options_set_write_buffer_size(options, 100000);
  rocksdb_options_set_paranoid_checks(options, 1);
  rocksdb_options_set_max_open_files(options, 10);
-  rocksdb_options_set_base_background_compactions(options, 1);

  table_options = rocksdb_block_based_options_create();
  rocksdb_block_based_options_set_block_cache(table_options, cache);
@@ -517,6 +486,9 @@ int main(int argc, char** argv) {
  coptions = rocksdb_compactoptions_create();
  rocksdb_compactoptions_set_exclusive_manual_compaction(coptions, 1);

+  rocksdb_options_add_compact_on_deletion_collector_factory(options, 10000,
+                                                            10001);
+
  StartPhase("destroy");
  rocksdb_destroy_db(options, dbname, &err);
  Free(&err);
@@ -1016,7 +988,36 @@ int main(int argc, char** argv) {
    CheckGet(db, roptions, "foo", NULL);
    rocksdb_release_snapshot(db, snap);
  }
-
+  StartPhase("snapshot_with_memtable_inplace_update");
+  {
+    rocksdb_close(db);
+    const rocksdb_snapshot_t* snap = NULL;
+    const char* s_key = "foo_snap";
+    const char* value1 = "hello_s1";
+    const char* value2 = "hello_s2";
+    rocksdb_options_set_allow_concurrent_memtable_write(options, 0);
+    rocksdb_options_set_inplace_update_support(options, 1);
+    rocksdb_options_set_error_if_exists(options, 0);
+    db = rocksdb_open(options, dbname, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, s_key, 8, value1, 8, &err);
+    snap = rocksdb_create_snapshot(db);
+    assert(snap != NULL);
+    rocksdb_put(db, woptions, s_key, 8, value2, 8, &err);
+    CheckNoError(err);
+    rocksdb_readoptions_set_snapshot(roptions, snap);
+    CheckGet(db, roptions, "foo", NULL);
+    // snapshot syntax is invalid, because of inplace update supported is set
+    CheckGet(db, roptions, s_key, value2);
+    // restore the data and options
+    rocksdb_delete(db, woptions, s_key, 8, &err);
+    CheckGet(db, roptions, s_key, NULL);
+    rocksdb_release_snapshot(db, snap);
+    rocksdb_readoptions_set_snapshot(roptions, NULL);
+    rocksdb_options_set_inplace_update_support(options, 0);
+    rocksdb_options_set_allow_concurrent_memtable_write(options, 1);
+    rocksdb_options_set_error_if_exists(options, 1);
+  }
  StartPhase("repair");
  {
    // If we do not compact here, then the lazy deletion of
@@ -1040,19 +1041,22 @@ int main(int argc, char** argv) {
  }

  StartPhase("filter");
-  for (run = 0; run <= 2; run++) {
-    // First run uses custom filter
-    // Second run uses old block-based bloom filter
-    // Third run uses full bloom filter
+  for (run = 1; run <= 4; run++) {
+    // run=0 uses custom filter (not currently supported)
+    // run=1 uses old block-based bloom filter
+    // run=2 run uses full bloom filter
+    // run=3 uses Ribbon
+    // run=4 uses Ribbon-Bloom hybrid configuration
    CheckNoError(err);
    rocksdb_filterpolicy_t* policy;
-    if (run == 0) {
-      policy = rocksdb_filterpolicy_create(NULL, FilterDestroy, FilterCreate,
-                                           FilterKeyMatch, NULL, FilterName);
-    } else if (run == 1) {
-      policy = rocksdb_filterpolicy_create_bloom(8);
+    if (run == 1) {
+      policy = rocksdb_filterpolicy_create_bloom(8.0);
+    } else if (run == 2) {
+      policy = rocksdb_filterpolicy_create_bloom_full(8.0);
+    } else if (run == 3) {
+      policy = rocksdb_filterpolicy_create_ribbon(8.0);
    } else {
-      policy = rocksdb_filterpolicy_create_bloom_full(8);
+      policy = rocksdb_filterpolicy_create_ribbon_hybrid(8.0, 1);
    }
    rocksdb_block_based_options_set_filter_policy(table_options, policy);

@@ -1080,19 +1084,8 @@ int main(int argc, char** argv) {
    }
    rocksdb_compact_range(db, NULL, 0, NULL, 0);

-    fake_filter_result = 1;
    CheckGet(db, roptions, "foo", "foovalue");
    CheckGet(db, roptions, "bar", "barvalue");
-    if (run == 0) {
-      // Must not find value when custom filter returns false
-      fake_filter_result = 0;
-      CheckGet(db, roptions, "foo", NULL);
-      CheckGet(db, roptions, "bar", NULL);
-      fake_filter_result = 1;
-
-      CheckGet(db, roptions, "foo", "foovalue");
-      CheckGet(db, roptions, "bar", "barvalue");
-    }

    {
      // Query some keys not added to identify Bloom filter implementation
@@ -1105,7 +1098,6 @@ int main(int argc, char** argv) {
      int i;
      char keybuf[100];
      for (i = 0; i < keys_to_query; i++) {
-        fake_filter_result = i % 2;
        snprintf(keybuf, sizeof(keybuf), "no%020d", i);
        CheckGet(db, roptions, keybuf, NULL);
      }
@@ -1115,12 +1107,15 @@ int main(int argc, char** argv) {
      if (run == 0) {
        // Due to half true, half false with fake filter result
        CheckCondition(hits == keys_to_query / 2);
-      } else if (run == 1) {
-        // Essentially a fingerprint of the block-based Bloom schema
-        CheckCondition(hits == 241);
-      } else {
+      } else if (run == 1 || run == 2 || run == 4) {
+        // For run == 1, block-based Bloom is no longer available in public
+        // API; attempting to enable it enables full Bloom instead.
+        //
        // Essentially a fingerprint of full Bloom schema, format_version=5
        CheckCondition(hits == 188);
+      } else {
+        // Essentially a fingerprint of Ribbon schema
+        CheckCondition(hits == 226);
      }
      CheckCondition(
          (keys_to_query - hits) ==
@@ -1276,6 +1271,9 @@ int main(int argc, char** argv) {
    CheckPinGetCF(db, roptions, handles[1], "box", "c");
    rocksdb_writebatch_destroy(wb);

+    rocksdb_flush_wal(db, 1, &err);
+    CheckNoError(err);
+
    const char* keys[3] = { "box", "box", "barfooxx" };
    const rocksdb_column_family_handle_t* get_handles[3] = { handles[0], handles[1], handles[1] };
    const size_t keys_sizes[3] = { 3, 3, 8 };
@@ -1598,9 +1596,6 @@ int main(int argc, char** argv) {
    rocksdb_options_set_max_background_compactions(o, 3);
    CheckCondition(3 == rocksdb_options_get_max_background_compactions(o));

-    rocksdb_options_set_base_background_compactions(o, 4);
-    CheckCondition(4 == rocksdb_options_get_base_background_compactions(o));
-
    rocksdb_options_set_max_background_flushes(o, 5);
    CheckCondition(5 == rocksdb_options_get_max_background_flushes(o));

@@ -1616,12 +1611,6 @@ int main(int argc, char** argv) {
    rocksdb_options_set_recycle_log_file_num(o, 9);
    CheckCondition(9 == rocksdb_options_get_recycle_log_file_num(o));

-    rocksdb_options_set_soft_rate_limit(o, 2.0);
-    CheckCondition(2.0 == rocksdb_options_get_soft_rate_limit(o));
-
-    rocksdb_options_set_hard_rate_limit(o, 4.0);
-    CheckCondition(4.0 == rocksdb_options_get_hard_rate_limit(o));
-
    rocksdb_options_set_soft_pending_compaction_bytes_limit(o, 10);
    CheckCondition(10 ==
                   rocksdb_options_get_soft_pending_compaction_bytes_limit(o));
@@ -1630,10 +1619,6 @@ int main(int argc, char** argv) {
    CheckCondition(11 ==
                   rocksdb_options_get_hard_pending_compaction_bytes_limit(o));

-    rocksdb_options_set_rate_limit_delay_max_milliseconds(o, 1);
-    CheckCondition(1 ==
-                   rocksdb_options_get_rate_limit_delay_max_milliseconds(o));
-
    rocksdb_options_set_max_manifest_file_size(o, 12);
    CheckCondition(12 == rocksdb_options_get_max_manifest_file_size(o));

@@ -1671,9 +1656,6 @@ int main(int argc, char** argv) {
    rocksdb_options_set_is_fd_close_on_exec(o, 1);
    CheckCondition(1 == rocksdb_options_get_is_fd_close_on_exec(o));

-    rocksdb_options_set_skip_log_error_on_recovery(o, 1);
-    CheckCondition(1 == rocksdb_options_get_skip_log_error_on_recovery(o));
-
    rocksdb_options_set_stats_dump_period_sec(o, 18);
    CheckCondition(18 == rocksdb_options_get_stats_dump_period_sec(o));

@@ -1759,6 +1741,12 @@ int main(int argc, char** argv) {
    rocksdb_options_set_atomic_flush(o, 1);
    CheckCondition(1 == rocksdb_options_get_atomic_flush(o));

+    rocksdb_options_set_manual_wal_flush(o, 1);
+    CheckCondition(1 == rocksdb_options_get_manual_wal_flush(o));
+
+    rocksdb_options_set_wal_compression(o, 1);
+    CheckCondition(1 == rocksdb_options_get_wal_compression(o));
+
    /* Blob Options */
    rocksdb_options_set_enable_blob_files(o, 1);
    CheckCondition(1 == rocksdb_options_get_enable_blob_files(o));
@@ -1775,8 +1763,15 @@ int main(int argc, char** argv) {
    rocksdb_options_set_enable_blob_gc(o, 1);
    CheckCondition(1 == rocksdb_options_get_enable_blob_gc(o));

-    rocksdb_options_set_blob_gc_age_cutoff(o, 0.75);
-    CheckCondition(0.75 == rocksdb_options_get_blob_gc_age_cutoff(o));
+    rocksdb_options_set_blob_gc_age_cutoff(o, 0.5);
+    CheckCondition(0.5 == rocksdb_options_get_blob_gc_age_cutoff(o));
+
+    rocksdb_options_set_blob_gc_force_threshold(o, 0.75);
+    CheckCondition(0.75 == rocksdb_options_get_blob_gc_force_threshold(o));
+
+    rocksdb_options_set_blob_compaction_readahead_size(o, 262144);
+    CheckCondition(262144 ==
+                   rocksdb_options_get_blob_compaction_readahead_size(o));

    // Create a copy that should be equal to the original.
    rocksdb_options_t* copy;
@@ -1823,20 +1818,15 @@ int main(int argc, char** argv) {
    CheckCondition(123456 == rocksdb_options_get_max_subcompactions(copy));
    CheckCondition(2 == rocksdb_options_get_max_background_jobs(copy));
    CheckCondition(3 == rocksdb_options_get_max_background_compactions(copy));
-    CheckCondition(4 == rocksdb_options_get_base_background_compactions(copy));
    CheckCondition(5 == rocksdb_options_get_max_background_flushes(copy));
    CheckCondition(6 == rocksdb_options_get_max_log_file_size(copy));
    CheckCondition(7 == rocksdb_options_get_log_file_time_to_roll(copy));
    CheckCondition(8 == rocksdb_options_get_keep_log_file_num(copy));
    CheckCondition(9 == rocksdb_options_get_recycle_log_file_num(copy));
-    CheckCondition(2.0 == rocksdb_options_get_soft_rate_limit(copy));
-    CheckCondition(4.0 == rocksdb_options_get_hard_rate_limit(copy));
    CheckCondition(
        10 == rocksdb_options_get_soft_pending_compaction_bytes_limit(copy));
    CheckCondition(
        11 == rocksdb_options_get_hard_pending_compaction_bytes_limit(copy));
-    CheckCondition(1 ==
-                   rocksdb_options_get_rate_limit_delay_max_milliseconds(copy));
    CheckCondition(12 == rocksdb_options_get_max_manifest_file_size(copy));
    CheckCondition(13 == rocksdb_options_get_table_cache_numshardbits(copy));
    CheckCondition(14 == rocksdb_options_get_arena_block_size(copy));
@@ -1850,7 +1840,6 @@ int main(int argc, char** argv) {
    CheckCondition(
        1 == rocksdb_options_get_use_direct_io_for_flush_and_compaction(copy));
    CheckCondition(1 == rocksdb_options_get_is_fd_close_on_exec(copy));
-    CheckCondition(1 == rocksdb_options_get_skip_log_error_on_recovery(copy));
    CheckCondition(18 == rocksdb_options_get_stats_dump_period_sec(copy));
    CheckCondition(5 == rocksdb_options_get_stats_persist_period_sec(copy));
    CheckCondition(1 == rocksdb_options_get_advise_random_on_open(copy));
@@ -2031,10 +2020,6 @@ int main(int argc, char** argv) {
    CheckCondition(13 == rocksdb_options_get_max_background_compactions(copy));
    CheckCondition(3 == rocksdb_options_get_max_background_compactions(o));

-    rocksdb_options_set_base_background_compactions(copy, 14);
-    CheckCondition(14 == rocksdb_options_get_base_background_compactions(copy));
-    CheckCondition(4 == rocksdb_options_get_base_background_compactions(o));
-
    rocksdb_options_set_max_background_flushes(copy, 15);
    CheckCondition(15 == rocksdb_options_get_max_background_flushes(copy));
    CheckCondition(5 == rocksdb_options_get_max_background_flushes(o));
@@ -2055,14 +2040,6 @@ int main(int argc, char** argv) {
    CheckCondition(19 == rocksdb_options_get_recycle_log_file_num(copy));
    CheckCondition(9 == rocksdb_options_get_recycle_log_file_num(o));

-    rocksdb_options_set_soft_rate_limit(copy, 4.0);
-    CheckCondition(4.0 == rocksdb_options_get_soft_rate_limit(copy));
-    CheckCondition(2.0 == rocksdb_options_get_soft_rate_limit(o));
-
-    rocksdb_options_set_hard_rate_limit(copy, 2.0);
-    CheckCondition(2.0 == rocksdb_options_get_hard_rate_limit(copy));
-    CheckCondition(4.0 == rocksdb_options_get_hard_rate_limit(o));
-
    rocksdb_options_set_soft_pending_compaction_bytes_limit(copy, 110);
    CheckCondition(
        110 == rocksdb_options_get_soft_pending_compaction_bytes_limit(copy));
@@ -2075,12 +2052,6 @@ int main(int argc, char** argv) {
    CheckCondition(11 ==
                   rocksdb_options_get_hard_pending_compaction_bytes_limit(o));

-    rocksdb_options_set_rate_limit_delay_max_milliseconds(copy, 0);
-    CheckCondition(0 ==
-                   rocksdb_options_get_rate_limit_delay_max_milliseconds(copy));
-    CheckCondition(1 ==
-                   rocksdb_options_get_rate_limit_delay_max_milliseconds(o));
-
    rocksdb_options_set_max_manifest_file_size(copy, 112);
    CheckCondition(112 == rocksdb_options_get_max_manifest_file_size(copy));
    CheckCondition(12 == rocksdb_options_get_max_manifest_file_size(o));
@@ -2132,10 +2103,6 @@ int main(int argc, char** argv) {
    CheckCondition(0 == rocksdb_options_get_is_fd_close_on_exec(copy));
    CheckCondition(1 == rocksdb_options_get_is_fd_close_on_exec(o));

-    rocksdb_options_set_skip_log_error_on_recovery(copy, 0);
-    CheckCondition(0 == rocksdb_options_get_skip_log_error_on_recovery(copy));
-    CheckCondition(1 == rocksdb_options_get_skip_log_error_on_recovery(o));
-
    rocksdb_options_set_stats_dump_period_sec(copy, 218);
    CheckCondition(218 == rocksdb_options_get_stats_dump_period_sec(copy));
    CheckCondition(18 == rocksdb_options_get_stats_dump_period_sec(o));
@@ -2481,53 +2448,75 @@ int main(int argc, char** argv) {
    rocksdb_fifo_compaction_options_destroy(fco);
  }

-  StartPhase("backupable_db_option");
+  StartPhase("backup_engine_option");
  {
-    rocksdb_backupable_db_options_t* bdo;
-    bdo = rocksdb_backupable_db_options_create("path");
+    rocksdb_backup_engine_options_t* bdo;
+    bdo = rocksdb_backup_engine_options_create("path");

-    rocksdb_backupable_db_options_set_share_table_files(bdo, 1);
+    rocksdb_backup_engine_options_set_share_table_files(bdo, 1);
    CheckCondition(1 ==
-                   rocksdb_backupable_db_options_get_share_table_files(bdo));
+                   rocksdb_backup_engine_options_get_share_table_files(bdo));

-    rocksdb_backupable_db_options_set_sync(bdo, 1);
-    CheckCondition(1 == rocksdb_backupable_db_options_get_sync(bdo));
+    rocksdb_backup_engine_options_set_sync(bdo, 1);
+    CheckCondition(1 == rocksdb_backup_engine_options_get_sync(bdo));

-    rocksdb_backupable_db_options_set_destroy_old_data(bdo, 1);
+    rocksdb_backup_engine_options_set_destroy_old_data(bdo, 1);
    CheckCondition(1 ==
-                   rocksdb_backupable_db_options_get_destroy_old_data(bdo));
+                   rocksdb_backup_engine_options_get_destroy_old_data(bdo));

-    rocksdb_backupable_db_options_set_backup_log_files(bdo, 1);
+    rocksdb_backup_engine_options_set_backup_log_files(bdo, 1);
    CheckCondition(1 ==
-                   rocksdb_backupable_db_options_get_backup_log_files(bdo));
+                   rocksdb_backup_engine_options_get_backup_log_files(bdo));

-    rocksdb_backupable_db_options_set_backup_rate_limit(bdo, 123);
+    rocksdb_backup_engine_options_set_backup_rate_limit(bdo, 123);
    CheckCondition(123 ==
-                   rocksdb_backupable_db_options_get_backup_rate_limit(bdo));
+                   rocksdb_backup_engine_options_get_backup_rate_limit(bdo));

-    rocksdb_backupable_db_options_set_restore_rate_limit(bdo, 37);
+    rocksdb_backup_engine_options_set_restore_rate_limit(bdo, 37);
    CheckCondition(37 ==
-                   rocksdb_backupable_db_options_get_restore_rate_limit(bdo));
+                   rocksdb_backup_engine_options_get_restore_rate_limit(bdo));

-    rocksdb_backupable_db_options_set_max_background_operations(bdo, 20);
+    rocksdb_backup_engine_options_set_max_background_operations(bdo, 20);
    CheckCondition(
-        20 == rocksdb_backupable_db_options_get_max_background_operations(bdo));
+        20 == rocksdb_backup_engine_options_get_max_background_operations(bdo));

-    rocksdb_backupable_db_options_set_callback_trigger_interval_size(bdo, 9000);
+    rocksdb_backup_engine_options_set_callback_trigger_interval_size(bdo, 9000);
    CheckCondition(
        9000 ==
-        rocksdb_backupable_db_options_get_callback_trigger_interval_size(bdo));
+        rocksdb_backup_engine_options_get_callback_trigger_interval_size(bdo));

-    rocksdb_backupable_db_options_set_max_valid_backups_to_open(bdo, 40);
+    rocksdb_backup_engine_options_set_max_valid_backups_to_open(bdo, 40);
    CheckCondition(
-        40 == rocksdb_backupable_db_options_get_max_valid_backups_to_open(bdo));
+        40 == rocksdb_backup_engine_options_get_max_valid_backups_to_open(bdo));

-    rocksdb_backupable_db_options_set_share_files_with_checksum_naming(bdo, 2);
+    rocksdb_backup_engine_options_set_share_files_with_checksum_naming(bdo, 2);
    CheckCondition(
-        2 == rocksdb_backupable_db_options_get_share_files_with_checksum_naming(
+        2 == rocksdb_backup_engine_options_get_share_files_with_checksum_naming(
                 bdo));

-    rocksdb_backupable_db_options_destroy(bdo);
+    rocksdb_backup_engine_options_destroy(bdo);
+  }
+
+  StartPhase("compression_options");
+  {
+    rocksdb_options_t* co;
+    co = rocksdb_options_create();
+
+    rocksdb_options_set_compression_options_zstd_max_train_bytes(co, 100);
+    CheckCondition(
+        100 ==
+        rocksdb_options_get_compression_options_zstd_max_train_bytes(co));
+
+    rocksdb_options_set_compression_options_parallel_threads(co, 2);
+    CheckCondition(
+        2 == rocksdb_options_get_compression_options_parallel_threads(co));
+
+    rocksdb_options_set_compression_options_max_dict_buffer_bytes(co, 200);
+    CheckCondition(
+        200 ==
+        rocksdb_options_get_compression_options_max_dict_buffer_bytes(co));
+
+    rocksdb_options_destroy(co);
  }

  StartPhase("iterate_upper_bound");
@@ -2909,6 +2898,51 @@ int main(int argc, char** argv) {
    CheckNoError(err);
  }

+  StartPhase("filter_with_prefix_seek");
+  {
+    rocksdb_close(db);
+    rocksdb_destroy_db(options, dbname, &err);
+    CheckNoError(err);
+
+    rocksdb_options_set_prefix_extractor(
+        options, rocksdb_slicetransform_create_fixed_prefix(1));
+    rocksdb_filterpolicy_t* filter_policy =
+        rocksdb_filterpolicy_create_bloom_full(8.0);
+    rocksdb_block_based_options_set_filter_policy(table_options, filter_policy);
+    rocksdb_options_set_block_based_table_factory(options, table_options);
+
+    db = rocksdb_open(options, dbname, &err);
+    CheckNoError(err);
+
+    int i;
+    for (i = 0; i < 10; ++i) {
+      char key = '0' + (char)i;
+      rocksdb_put(db, woptions, &key, 1, "", 1, &err);
+      CheckNoError(err);
+    }
+
+    // Flush to generate an L0 so that filter will be used later.
+    rocksdb_flushoptions_t* flush_options = rocksdb_flushoptions_create();
+    rocksdb_flushoptions_set_wait(flush_options, 1);
+    rocksdb_flush(db, flush_options, &err);
+    rocksdb_flushoptions_destroy(flush_options);
+    CheckNoError(err);
+
+    rocksdb_readoptions_t* ropts = rocksdb_readoptions_create();
+    rocksdb_iterator_t* iter = rocksdb_create_iterator(db, ropts);
+
+    rocksdb_iter_seek(iter, "0", 1);
+    int cnt = 0;
+    while (rocksdb_iter_valid(iter)) {
+      ++cnt;
+      rocksdb_iter_next(iter);
+    }
+    CheckCondition(10 == cnt);
+
+    rocksdb_iter_destroy(iter);
+    rocksdb_readoptions_destroy(ropts);
+  }
+
  StartPhase("cancel_all_background_work");
  rocksdb_cancel_all_background_work(db, 1);

@@ -2919,7 +2953,6 @@ int main(int argc, char** argv) {
  rocksdb_readoptions_destroy(roptions);
  rocksdb_writeoptions_destroy(woptions);
  rocksdb_compactoptions_destroy(coptions);
-  rocksdb_cache_disown_data(cache);
  rocksdb_cache_destroy(cache);
  rocksdb_comparator_destroy(cmp);
  rocksdb_dbpath_destroy(dbpath);
@@ -29,7 +29,7 @@
 #include "db/version_set.h"
 #include "db/write_controller.h"
 #include "file/sst_file_manager_impl.h"
-#include "memtable/hash_skiplist_rep.h"
+#include "logging/logging.h"
 #include "monitoring/thread_status_util.h"
 #include "options/options_helper.h"
 #include "port/port.h"
@@ -75,11 +75,6 @@ ColumnFamilyHandleImpl::~ColumnFamilyHandleImpl() {
      bool defer_purge =
          db_->immutable_db_options().avoid_unnecessary_blocking_io;
      db_->PurgeObsoleteFiles(job_context, defer_purge);
-      if (defer_purge) {
-        mutex_->Lock();
-        db_->SchedulePurge();
-        mutex_->Unlock();
-      }
    }
    job_context.Clean();
  }
@@ -109,8 +104,9 @@ const Comparator* ColumnFamilyHandleImpl::GetComparator() const {

 void GetIntTblPropCollectorFactory(
    const ImmutableCFOptions& ioptions,
-    std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-        int_tbl_prop_collector_factories) {
+    IntTblPropCollectorFactories* int_tbl_prop_collector_factories) {
+  assert(int_tbl_prop_collector_factories);
+
  auto& collector_factories = ioptions.table_properties_collector_factories;
  for (size_t i = 0; i < ioptions.table_properties_collector_factories.size();
       ++i) {
@@ -202,7 +198,7 @@ Status CheckCFPathsSupported(const DBOptions& db_options,
 namespace {
 const uint64_t kDefaultTtl = 0xfffffffffffffffe;
 const uint64_t kDefaultPeriodicCompSecs = 0xfffffffffffffffe;
-};  // namespace
+}  // namespace

 ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
                                    const ColumnFamilyOptions& src) {
@@ -210,11 +206,13 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
  size_t clamp_max = std::conditional<
      sizeof(size_t) == 4, std::integral_constant<size_t, 0xffffffff>,
      std::integral_constant<uint64_t, 64ull << 30>>::type::value;
-  ClipToRange(&result.write_buffer_size, ((size_t)64) << 10, clamp_max);
+  ClipToRange(&result.write_buffer_size, (static_cast<size_t>(64)) << 10,
+              clamp_max);
  // if user sets arena_block_size, we trust user to use this value. Otherwise,
  // calculate a proper value from writer_buffer_size;
  if (result.arena_block_size <= 0) {
-    result.arena_block_size = result.write_buffer_size / 8;
+    result.arena_block_size =
+        std::min(size_t{1024 * 1024}, result.write_buffer_size / 8);

    // Align up to 4k
    const size_t align = 4 * 1024;
@@ -283,7 +281,7 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
  }

  if (result.level0_file_num_compaction_trigger == 0) {
-    ROCKS_LOG_WARN(db_options.info_log.get(),
+    ROCKS_LOG_WARN(db_options.logger,
                   "level0_file_num_compaction_trigger cannot be 0");
    result.level0_file_num_compaction_trigger = 1;
  }
@@ -292,7 +290,7 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
          result.level0_slowdown_writes_trigger ||
      result.level0_slowdown_writes_trigger <
          result.level0_file_num_compaction_trigger) {
-    ROCKS_LOG_WARN(db_options.info_log.get(),
+    ROCKS_LOG_WARN(db_options.logger,
                   "This condition must be satisfied: "
                   "level0_stop_writes_trigger(%d) >= "
                   "level0_slowdown_writes_trigger(%d) >= "
@@ -309,7 +307,7 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
        result.level0_slowdown_writes_trigger) {
      result.level0_stop_writes_trigger = result.level0_slowdown_writes_trigger;
    }
-    ROCKS_LOG_WARN(db_options.info_log.get(),
+    ROCKS_LOG_WARN(db_options.logger,
                   "Adjust the value to "
                   "level0_stop_writes_trigger(%d)"
                   "level0_slowdown_writes_trigger(%d)"
@@ -347,12 +345,18 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
  }

  if (result.level_compaction_dynamic_level_bytes) {
-    if (result.compaction_style != kCompactionStyleLevel ||
-        result.cf_paths.size() > 1U) {
-      // 1. level_compaction_dynamic_level_bytes only makes sense for
-      //    level-based compaction.
-      // 2. we don't yet know how to make both of this feature and multiple
-      //    DB path work.
+    if (result.compaction_style != kCompactionStyleLevel) {
+      ROCKS_LOG_WARN(db_options.info_log.get(),
+                     "level_compaction_dynamic_level_bytes only makes sense"
+                     "for level-based compaction");
+      result.level_compaction_dynamic_level_bytes = false;
+    } else if (result.cf_paths.size() > 1U) {
+      // we don't yet know how to make both of this feature and multiple
+      // DB path work.
+      ROCKS_LOG_WARN(db_options.info_log.get(),
+                     "multiple cf_paths/db_paths and"
+                     "level_compaction_dynamic_level_bytes"
+                     "can't be used together");
      result.level_compaction_dynamic_level_bytes = false;
    }
  }
@@ -443,6 +447,9 @@ bool SuperVersion::Unref() {

 void SuperVersion::Cleanup() {
  assert(refs.load(std::memory_order_relaxed) == 0);
+  // Since this SuperVersion object is being deleted,
+  // decrement reference to the immutable MemtableList
+  // this SV object was pointing to.
  imm->Unref(&to_delete);
  MemTable* m = mem->Unref();
  if (m != nullptr) {
@@ -452,7 +459,7 @@ void SuperVersion::Cleanup() {
    to_delete.push_back(m);
  }
  current->Unref();
-  cfd->UnrefAndTryDelete(this);
+  cfd->UnrefAndTryDelete();
 }

 void SuperVersion::Init(ColumnFamilyData* new_cfd, MemTable* new_mem,
@@ -470,10 +477,10 @@ void SuperVersion::Init(ColumnFamilyData* new_cfd, MemTable* new_mem,

 namespace {
 void SuperVersionUnrefHandle(void* ptr) {
-  // UnrefHandle is called when a thread exists or a ThreadLocalPtr gets
-  // destroyed. When former happens, the thread shouldn't see kSVInUse.
-  // When latter happens, we are in ~ColumnFamilyData(), no get should happen as
-  // well.
+  // UnrefHandle is called when a thread exits or a ThreadLocalPtr gets
+  // destroyed. When the former happens, the thread shouldn't see kSVInUse.
+  // When the latter happens, only super_version_ holds a reference
+  // to ColumnFamilyData, so no further queries are possible.
  SuperVersion* sv = static_cast<SuperVersion*>(ptr);
  bool was_last_ref __attribute__((__unused__));
  was_last_ref = sv->Unref();
@@ -500,9 +507,10 @@ ColumnFamilyData::ColumnFamilyData(
    uint32_t id, const std::string& name, Version* _dummy_versions,
    Cache* _table_cache, WriteBufferManager* write_buffer_manager,
    const ColumnFamilyOptions& cf_options, const ImmutableDBOptions& db_options,
-    const FileOptions& file_options, ColumnFamilySet* column_family_set,
+    const FileOptions* file_options, ColumnFamilySet* column_family_set,
    BlockCacheTracer* const block_cache_tracer,
-    const std::shared_ptr<IOTracer>& io_tracer)
+    const std::shared_ptr<IOTracer>& io_tracer,
+    const std::string& db_session_id)
    : id_(id),
      name_(name),
      dummy_versions_(_dummy_versions),
@@ -545,7 +553,7 @@ ColumnFamilyData::ColumnFamilyData(
      db_paths_registered_ = true;
    } else {
      ROCKS_LOG_ERROR(
-          ioptions_.info_log,
+          ioptions_.logger,
          "Failed to register data paths of column family (id: %d, name: %s)",
          id_, name_.c_str());
    }
@@ -560,7 +568,8 @@ ColumnFamilyData::ColumnFamilyData(
    internal_stats_.reset(
        new InternalStats(ioptions_.num_levels, ioptions_.clock, this));
    table_cache_.reset(new TableCache(ioptions_, file_options, _table_cache,
-                                      block_cache_tracer, io_tracer));
+                                      block_cache_tracer, io_tracer,
+                                      db_session_id));
    blob_file_cache_.reset(
        new BlobFileCache(_table_cache, ioptions(), soptions(), id_,
                          internal_stats_->GetBlobFileReadHist(), io_tracer));
@@ -578,13 +587,13 @@ ColumnFamilyData::ColumnFamilyData(
    } else if (ioptions_.compaction_style == kCompactionStyleNone) {
      compaction_picker_.reset(new NullCompactionPicker(
          ioptions_, &internal_comparator_));
-      ROCKS_LOG_WARN(ioptions_.info_log,
+      ROCKS_LOG_WARN(ioptions_.logger,
                     "Column family %s does not use any background compaction. "
                     "Compactions can only be done via CompactFiles\n",
                     GetName().c_str());
 #endif  // !ROCKSDB_LITE
    } else {
-      ROCKS_LOG_ERROR(ioptions_.info_log,
+      ROCKS_LOG_ERROR(ioptions_.logger,
                      "Unable to recognize the specified compaction style %d. "
                      "Column family %s will use kCompactionStyleLevel.\n",
                      ioptions_.compaction_style, GetName().c_str());
@@ -593,12 +602,12 @@ ColumnFamilyData::ColumnFamilyData(
    }

    if (column_family_set_->NumberOfColumnFamilies() < 10) {
-      ROCKS_LOG_INFO(ioptions_.info_log,
+      ROCKS_LOG_INFO(ioptions_.logger,
                     "--------------- Options for column family [%s]:\n",
                     name.c_str());
-      initial_cf_options_.Dump(ioptions_.info_log);
+      initial_cf_options_.Dump(ioptions_.logger);
    } else {
-      ROCKS_LOG_INFO(ioptions_.info_log, "\t(skipping printing options)\n");
+      ROCKS_LOG_INFO(ioptions_.logger, "\t(skipping printing options)\n");
    }
  }

@@ -654,14 +663,14 @@ ColumnFamilyData::~ColumnFamilyData() {
    Status s = ioptions_.env->UnregisterDbPaths(GetDbPaths());
    if (!s.ok()) {
      ROCKS_LOG_ERROR(
-          ioptions_.info_log,
+          ioptions_.logger,
          "Failed to unregister data paths of column family (id: %d, name: %s)",
          id_, name_.c_str());
    }
  }
 }

-bool ColumnFamilyData::UnrefAndTryDelete(SuperVersion* sv_under_cleanup) {
+bool ColumnFamilyData::UnrefAndTryDelete() {
  int old_refs = refs_.fetch_sub(1);
  assert(old_refs > 0);

@@ -671,22 +680,17 @@ bool ColumnFamilyData::UnrefAndTryDelete(SuperVersion* sv_under_cleanup) {
    return true;
  }

-  // If called under SuperVersion::Cleanup, we should not re-enter Cleanup on
-  // the same SuperVersion. (But while installing a new SuperVersion, this
-  // cfd could be referenced only by two SuperVersions.)
-  if (old_refs == 2 && super_version_ != nullptr &&
-      super_version_ != sv_under_cleanup) {
+  if (old_refs == 2 && super_version_ != nullptr) {
    // Only the super_version_ holds me
    SuperVersion* sv = super_version_;
    super_version_ = nullptr;
-    // Release SuperVersion reference kept in ThreadLocalPtr.
-    // This must be done outside of mutex_ since unref handler can lock mutex.
-    sv->db_mutex->Unlock();
+
+    // Release SuperVersion references kept in ThreadLocalPtr.
    local_sv_.reset();
-    sv->db_mutex->Lock();

    if (sv->Unref()) {
-      // May delete this ColumnFamilyData after calling Cleanup()
+      // Note: sv will delete this ColumnFamilyData during Cleanup()
+      assert(sv->cfd == this);
      sv->Cleanup();
      delete sv;
      return true;
@@ -893,7 +897,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
      write_controller_token_ = write_controller->GetStopToken();
      internal_stats_->AddCFStats(InternalStats::MEMTABLE_LIMIT_STOPS, 1);
      ROCKS_LOG_WARN(
-          ioptions_.info_log,
+          ioptions_.logger,
          "[%s] Stopping writes because we have %d immutable memtables "
          "(waiting for flush), max_write_buffer_number is set to %d",
          name_.c_str(), imm()->NumNotFlushed(),
@@ -906,7 +910,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
        internal_stats_->AddCFStats(
            InternalStats::LOCKED_L0_FILE_COUNT_LIMIT_STOPS, 1);
      }
-      ROCKS_LOG_WARN(ioptions_.info_log,
+      ROCKS_LOG_WARN(ioptions_.logger,
                     "[%s] Stopping writes because we have %d level-0 files",
                     name_.c_str(), vstorage->l0_delay_trigger_count());
    } else if (write_stall_condition == WriteStallCondition::kStopped &&
@@ -915,7 +919,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
      internal_stats_->AddCFStats(
          InternalStats::PENDING_COMPACTION_BYTES_LIMIT_STOPS, 1);
      ROCKS_LOG_WARN(
-          ioptions_.info_log,
+          ioptions_.logger,
          "[%s] Stopping writes because of estimated pending compaction "
          "bytes %" PRIu64,
          name_.c_str(), compaction_needed_bytes);
@@ -927,7 +931,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
                     mutable_cf_options.disable_auto_compactions);
      internal_stats_->AddCFStats(InternalStats::MEMTABLE_LIMIT_SLOWDOWNS, 1);
      ROCKS_LOG_WARN(
-          ioptions_.info_log,
+          ioptions_.logger,
          "[%s] Stalling writes because we have %d immutable memtables "
          "(waiting for flush), max_write_buffer_number is set to %d "
          "rate %" PRIu64,
@@ -949,7 +953,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
        internal_stats_->AddCFStats(
            InternalStats::LOCKED_L0_FILE_COUNT_LIMIT_SLOWDOWNS, 1);
      }
-      ROCKS_LOG_WARN(ioptions_.info_log,
+      ROCKS_LOG_WARN(ioptions_.logger,
                     "[%s] Stalling writes because we have %d level-0 files "
                     "rate %" PRIu64,
                     name_.c_str(), vstorage->l0_delay_trigger_count(),
@@ -974,7 +978,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
      internal_stats_->AddCFStats(
          InternalStats::PENDING_COMPACTION_BYTES_LIMIT_SLOWDOWNS, 1);
      ROCKS_LOG_WARN(
-          ioptions_.info_log,
+          ioptions_.logger,
          "[%s] Stalling writes because of estimated pending compaction "
          "bytes %" PRIu64 " rate %" PRIu64,
          name_.c_str(), vstorage->estimated_compaction_needed_bytes(),
@@ -988,7 +992,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
        write_controller_token_ =
            write_controller->GetCompactionPressureToken();
        ROCKS_LOG_INFO(
-            ioptions_.info_log,
+            ioptions_.logger,
            "[%s] Increasing compaction threads because we have %d level-0 "
            "files ",
            name_.c_str(), vstorage->l0_delay_trigger_count());
@@ -1002,7 +1006,7 @@ WriteStallCondition ColumnFamilyData::RecalculateWriteStallConditions(
            write_controller->GetCompactionPressureToken();
        if (mutable_cf_options.soft_pending_compaction_bytes_limit > 0) {
          ROCKS_LOG_INFO(
-              ioptions_.info_log,
+              ioptions_.logger,
              "[%s] Increasing compaction threads because of estimated pending "
              "compaction "
              "bytes %" PRIu64,
@@ -1047,6 +1051,10 @@ uint64_t ColumnFamilyData::GetTotalSstFilesSize() const {
  return VersionSet::GetTotalSstFilesSize(dummy_versions_);
 }

+uint64_t ColumnFamilyData::GetTotalBlobFileSize() const {
+  return VersionSet::GetTotalBlobFileSize(dummy_versions_);
+}
+
 uint64_t ColumnFamilyData::GetLiveSstFilesSize() const {
  return current_->GetSstFilesSize();
 }
@@ -1156,12 +1164,12 @@ Compaction* ColumnFamilyData::CompactRange(
    int output_level, const CompactRangeOptions& compact_range_options,
    const InternalKey* begin, const InternalKey* end,
    InternalKey** compaction_end, bool* conflict,
-    uint64_t max_file_num_to_ignore) {
+    uint64_t max_file_num_to_ignore, const std::string& trim_ts) {
  auto* result = compaction_picker_->CompactRange(
      GetName(), mutable_cf_options, mutable_db_options,
      current_->storage_info(), input_level, output_level,
      compact_range_options, begin, end, compaction_end, conflict,
-      max_file_num_to_ignore);
+      max_file_num_to_ignore, trim_ts);
  if (result != nullptr) {
    result->SetInputVersion(current_);
  }
@@ -1203,11 +1211,11 @@ SuperVersion* ColumnFamilyData::GetThreadLocalSuperVersion(DBImpl* db) {
  SuperVersion* sv = static_cast<SuperVersion*>(ptr);
  if (sv == SuperVersion::kSVObsolete ||
      sv->version_number != super_version_number_.load()) {
-    RecordTick(ioptions_.statistics, NUMBER_SUPERVERSION_ACQUIRES);
+    RecordTick(ioptions_.stats, NUMBER_SUPERVERSION_ACQUIRES);
    SuperVersion* sv_to_delete = nullptr;

    if (sv && sv->Unref()) {
-      RecordTick(ioptions_.statistics, NUMBER_SUPERVERSION_CLEANUPS);
+      RecordTick(ioptions_.stats, NUMBER_SUPERVERSION_CLEANUPS);
      db->mutex()->Lock();
      // NOTE: underlying resources held by superversion (sst files) might
      // not be released until the next background job.
@@ -1251,14 +1259,13 @@ bool ColumnFamilyData::ReturnThreadLocalSuperVersion(SuperVersion* sv) {
 void ColumnFamilyData::InstallSuperVersion(
    SuperVersionContext* sv_context, InstrumentedMutex* db_mutex) {
  db_mutex->AssertHeld();
-  return InstallSuperVersion(sv_context, db_mutex, mutable_cf_options_);
+  return InstallSuperVersion(sv_context, mutable_cf_options_);
 }

 void ColumnFamilyData::InstallSuperVersion(
-    SuperVersionContext* sv_context, InstrumentedMutex* db_mutex,
+    SuperVersionContext* sv_context,
    const MutableCFOptions& mutable_cf_options) {
  SuperVersion* new_superversion = sv_context->new_superversion.release();
-  new_superversion->db_mutex = db_mutex;
  new_superversion->mutable_cf_options = mutable_cf_options;
  new_superversion->Init(this, mem_, imm_.current(), current_);
  SuperVersion* old_superversion = super_version_;
@@ -1347,12 +1354,19 @@ Status ColumnFamilyData::ValidateOptions(
    }
  }

-  if (cf_options.enable_blob_garbage_collection &&
-      (cf_options.blob_garbage_collection_age_cutoff < 0.0 ||
-       cf_options.blob_garbage_collection_age_cutoff > 1.0)) {
-    return Status::InvalidArgument(
-        "The age cutoff for blob garbage collection should be in the range "
-        "[0.0, 1.0].");
+  if (cf_options.enable_blob_garbage_collection) {
+    if (cf_options.blob_garbage_collection_age_cutoff < 0.0 ||
+        cf_options.blob_garbage_collection_age_cutoff > 1.0) {
+      return Status::InvalidArgument(
+          "The age cutoff for blob garbage collection should be in the range "
+          "[0.0, 1.0].");
+    }
+    if (cf_options.blob_garbage_collection_force_threshold < 0.0 ||
+        cf_options.blob_garbage_collection_force_threshold > 1.0) {
+      return Status::InvalidArgument(
+          "The garbage ratio threshold for forcing blob garbage collection "
+          "should be in the range [0.0, 1.0].");
+    }
  }

  if (cf_options.compaction_style == kCompactionStyleFIFO &&
@@ -1417,7 +1431,8 @@ Status ColumnFamilyData::AddDirectories(

    if (existing_dir == created_dirs->end()) {
      std::unique_ptr<FSDirectory> path_directory;
-      s = DBImpl::CreateAndNewDirectory(ioptions_.fs, p.path, &path_directory);
+      s = DBImpl::CreateAndNewDirectory(ioptions_.fs.get(), p.path,
+                                        &path_directory);
      if (!s.ok()) {
        return s;
      }
@@ -1448,21 +1463,23 @@ ColumnFamilySet::ColumnFamilySet(const std::string& dbname,
                                 WriteBufferManager* _write_buffer_manager,
                                 WriteController* _write_controller,
                                 BlockCacheTracer* const block_cache_tracer,
-                                 const std::shared_ptr<IOTracer>& io_tracer)
+                                 const std::shared_ptr<IOTracer>& io_tracer,
+                                 const std::string& db_session_id)
    : max_column_family_(0),
+      file_options_(file_options),
      dummy_cfd_(new ColumnFamilyData(
          ColumnFamilyData::kDummyColumnFamilyDataId, "", nullptr, nullptr,
-          nullptr, ColumnFamilyOptions(), *db_options, file_options, nullptr,
-          block_cache_tracer, io_tracer)),
+          nullptr, ColumnFamilyOptions(), *db_options, &file_options_, nullptr,
+          block_cache_tracer, io_tracer, db_session_id)),
      default_cfd_cache_(nullptr),
      db_name_(dbname),
      db_options_(db_options),
-      file_options_(file_options),
      table_cache_(table_cache),
      write_buffer_manager_(_write_buffer_manager),
      write_controller_(_write_controller),
      block_cache_tracer_(block_cache_tracer),
-      io_tracer_(io_tracer) {
+      io_tracer_(io_tracer),
+      db_session_id_(db_session_id) {
  // initialize linked list
  dummy_cfd_->prev_ = dummy_cfd_;
  dummy_cfd_->next_ = dummy_cfd_;
@@ -1528,7 +1545,8 @@ ColumnFamilyData* ColumnFamilySet::CreateColumnFamily(
  assert(column_families_.find(name) == column_families_.end());
  ColumnFamilyData* new_cfd = new ColumnFamilyData(
      id, name, dummy_versions, table_cache_, write_buffer_manager_, options,
-      *db_options_, file_options_, this, block_cache_tracer_, io_tracer_);
+      *db_options_, &file_options_, this, block_cache_tracer_, io_tracer_,
+      db_session_id_);
  column_families_.insert({name, id});
  column_family_data_.insert({id, new_cfd});
  max_column_family_ = std::max(max_column_family_, id);
@@ -1544,20 +1562,6 @@ ColumnFamilyData* ColumnFamilySet::CreateColumnFamily(
  return new_cfd;
 }

-// REQUIRES: DB mutex held
-void ColumnFamilySet::FreeDeadColumnFamilies() {
-  autovector<ColumnFamilyData*> to_delete;
-  for (auto cfd = dummy_cfd_->next_; cfd != dummy_cfd_; cfd = cfd->next_) {
-    if (cfd->refs_.load(std::memory_order_relaxed) == 0) {
-      to_delete.push_back(cfd);
-    }
-  }
-  for (auto cfd : to_delete) {
-    // this is very rare, so it's not a problem that we do it under a mutex
-    delete cfd;
-  }
-}
-
 // under a DB mutex AND from a write thread
 void ColumnFamilySet::RemoveColumnFamily(ColumnFamilyData* cfd) {
  auto cfd_iter = column_family_data_.find(cfd->GetID());
--- a/Show More
+++ b/Show More