Fix atomic flush waiting forever for MANIFEST write (#9034 )

Summary: In atomic flush, concurrent background flush threads will commit to the MANIFEST one by one, in the order of the IDs of their picked memtables for all included column families. Each time, a background flush thread decides whether to wait based on two criteria: - Is db stopped? If so, don't wait. - Am I the one to commit the currently earliest memtable? If so, don't wait and ready to go. When atomic flush was implemented, error writing to or syncing the MANIFEST would cause the db to be stopped. Therefore, this background thread does not have to check for the background error while waiting. If there has been such an error, `DBStopped()` would have been true, and this thread will **not** wait forever. After we improved error handling, RocksDB may map an IOError while writing to MANIFEST to a soft error, if there is no WAL. This requires the background threads to check for background error while waiting. Otherwise, a background flush thread may wait forever. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9034 Test Plan: make check Reviewed By: zhichao-cao Differential Revision: D31639225 Pulled By: riversand963 fbshipit-source-id: e9ab07c4d8f2eade238adeefe3e42dd9a5a3ebbd
Update Release Version to 6.26 (#9059 )
2026-07-08 07:05:23 +08:00 · 2021-10-20 21:34:47 -07:00 · 2021-10-20 15:32:01 -07:00 · 2021-10-20 14:08:05 -07:00 · 2021-10-20 14:04:59 -07:00 · 2021-10-20 13:17:00 -07:00
764 changed files with 64306 additions and 16989 deletions
@@ -5,9 +5,9 @@ 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:
@@ -49,6 +49,9 @@ commands:
            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

  pre-steps-macos:
      steps:
@@ -57,7 +60,7 @@ commands:

  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
@@ -88,6 +91,21 @@ commands:
          command: |
            sudo apt-get update -y && sudo apt-get install -y libgflags-dev

+  install-benchmark:
+    steps:
+      - run: # currently doesn't support ubuntu-1604 which doesn't have libbenchmark package, user can still install by building it youself
+          name: Install benchmark
+          command: |
+            sudo apt-get update -y && sudo apt-get install -y libbenchmark-dev
+
+  upgrade-cmake:
+    steps:
+      - run:
+          name: Upgrade cmake
+          command: |
+            sudo apt remove --purge cmake
+            sudo snap install cmake --classic
+
  install-gflags-on-macos:
    steps:
      - run:
@@ -120,7 +138,8 @@ executors:
 jobs:
  build-macos:
    macos:
-      xcode: 9.4.1
+      xcode: 11.3.0
+    resource_class: large
    steps:
      - increase-max-open-files-on-macos
      - install-pyenv-on-macos
@@ -131,19 +150,20 @@ jobs:

  build-macos-cmake:
    macos:
-      xcode: 9.4.1
+      xcode: 11.3.0
+    resource_class: large
    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: ulimit -S -n 1048576 && (mkdir build && cd build && cmake -DWITH_GFLAGS=1 .. && make V=1 -j32 && ctest -j10) | .circleci/cat_ignore_eagain
      - post-steps

  build-linux:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -153,7 +173,7 @@ jobs:

  build-linux-mem-env:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -163,7 +183,7 @@ jobs:

  build-linux-encrypted-env:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -173,7 +193,7 @@ jobs:

  build-linux-shared_lib-alt_namespace-status_checked:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -183,7 +203,7 @@ jobs:

  build-linux-release:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: large
    steps:
      - checkout # check out the code in the project directory
@@ -210,7 +230,7 @@ jobs:

  build-linux-lite:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -220,7 +240,7 @@ jobs:

  build-linux-lite-release:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: large
    steps:
      - checkout # check out the code in the project directory
@@ -233,17 +253,17 @@ jobs:

  build-linux-clang-no_test_run:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    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: 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 | .circleci/cat_ignore_eagain
      - post-steps

  build-linux-clang10-asan:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -254,7 +274,7 @@ jobs:

  build-linux-clang10-mini-tsan:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -265,7 +285,7 @@ jobs:

  build-linux-clang10-ubsan:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -276,7 +296,7 @@ jobs:

  build-linux-clang10-clang-analyze:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -286,16 +306,29 @@ jobs:
      - 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.
      - post-steps

-  build-linux-cmake-no_test_run:
+  build-linux-cmake:
    machine:
-      image: ubuntu-1604:202007-01
-    resource_class: large
+      image: ubuntu-1604:202104-01
+    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) | .circleci/cat_ignore_eagain
      - post-steps

-  build-linux-unity:
+  build-linux-cmake-ubuntu-20:
+    machine:
+      image: ubuntu-2004:202104-01
+    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 && make microbench) | .circleci/cat_ignore_eagain
+      - post-steps
+
+  build-linux-unity-and-headers:
    docker: # executor type
      - image: gcc:latest
    resource_class: large
@@ -303,11 +336,12 @@ jobs:
      - 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: make V=1 -j8 -k check-headers | .circleci/cat_ignore_eagain # could be moved to a different build
      - post-steps

  build-linux-gcc-4_8-no_test_run:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: large
    steps:
      - pre-steps
@@ -345,6 +379,27 @@ jobs:
      - 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
      - post-steps

+  build-linux-gcc-11-no_test_run:
+    machine:
+      image: ubuntu-2004:202010-01
+    resource_class: xlarge
+    steps:
+      - pre-steps
+      - run: sudo apt-get update -y && sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test && sudo apt-get install gcc-11 g++-11 libgflags-dev
+      - run: CC=gcc-11 CXX=g++-11 V=1 SKIP_LINK=1 make -j16 all | .circleci/cat_ignore_eagain # Linking broken because libgflags compiled with newer ABI
+      - 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-microbench:
+    machine:
+      image: ubuntu-2004:202010-01
+    resource_class: xlarge
+    steps:
+      - pre-steps
+      - install-benchmark
+      - run: DEBUG_LEVEL=0 make microbench | .circleci/cat_ignore_eagain
+      - post-steps
+
  build-windows:
    executor: windows-2xlarge
    parameters:
@@ -380,6 +435,8 @@ 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 +470,7 @@ jobs:

  build-linux-java:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: large
    environment:
      JAVA_HOME: /usr/lib/jvm/java-1.8.0-openjdk-amd64
@@ -437,7 +494,7 @@ jobs:

  build-linux-java-static:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: large
    environment:
      JAVA_HOME: /usr/lib/jvm/java-1.8.0-openjdk-amd64
@@ -458,10 +515,10 @@ jobs:

  build-macos-java:
    macos:
-      xcode: 9.4.1
+      xcode: 11.3.0
    resource_class: medium
    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
@@ -484,10 +541,10 @@ jobs:

  build-macos-java-static:
    macos:
-      xcode: 9.4.1
+      xcode: 11.3.0
    resource_class: medium
    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
@@ -508,7 +565,7 @@ jobs:

  build-examples:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: large
    steps:
      - pre-steps
@@ -521,7 +578,7 @@ jobs:

  build-cmake-mingw:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -544,7 +601,7 @@ jobs:

  build-linux-non-shm:
    machine:
-      image: ubuntu-1604:202007-01
+      image: ubuntu-1604:202104-01
    resource_class: 2xlarge
    parameters:
      start_test:
@@ -572,9 +629,62 @@ jobs:
            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-arm-test-full:
+    machine:
+      image: ubuntu-2004:202101-01
+    resource_class: arm.large
+    steps:
+      - pre-steps
+      - install-gflags
+      - run: make V=1 J=4 -j4 check | .circleci/cat_ignore_eagain
+      - post-steps
+
+  build-linux-arm:
+    machine:
+      image: ubuntu-2004:202101-01
+    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
+      - post-steps
+
+  build-linux-arm-cmake-no_test_run:
+    machine:
+      image: ubuntu-2004:202101-01
+    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: |
+            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 with cmake"
+          command: |
+            mkdir build
+            cd build
+            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"
+          command: |
+            rm -rf build
+            mkdir build
+            cd build
+            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-1604:202104-01
    resource_class: 2xlarge
    steps:
      - pre-steps
@@ -594,6 +704,10 @@ workflows:
  build-linux:
    jobs:
      - build-linux
+  build-linux-cmake:
+    jobs:
+      - build-linux-cmake
+      - build-linux-cmake-ubuntu-20
  build-linux-mem-env:
    jobs:
      - build-linux-mem-env
@@ -627,9 +741,9 @@ workflows:
  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-windows-vs2019:
    jobs:
      - build-windows:
@@ -645,12 +759,6 @@ 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
@@ -677,11 +785,12 @@ workflows:
  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-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
@@ -691,6 +800,12 @@ workflows:
  build-cmake-mingw:
    jobs:
      - build-cmake-mingw
+  build-linux-arm:
+    jobs:
+      - build-linux-arm
+  build-microbench:
+    jobs:
+      - build-linux-microbench
  nightly:
    triggers:
      - schedule:
@@ -698,6 +813,7 @@ workflows:
          filters:
            branches:
              only:
-                - master
+                - main
    jobs:
      - build-format-compatible
+      - build-linux-arm-test-full
@@ -39,3 +39,6 @@ jobs:

    - name: Compare buckify output
      run: make check-buck-targets
+
+    - name: Simple source code checks
+      run: make check-sources
@@ -61,6 +61,10 @@ matrix:
    env: JOB_NAME=make-gcc4.8
  - os: linux
    compiler: clang
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os: linux
+    arch: arm64
+    env: TEST_GROUP=platform_dependent
  - if: type = pull_request AND commit_message !~ /FULL_CI/
    os : linux
    arch: arm64
@@ -93,6 +97,10 @@ matrix:
    os: linux
    arch: ppc64le
    env: TEST_GROUP=4
+  - if: type = pull_request AND commit_message !~ /FULL_CI/
+    os : linux
+    arch: arm64
+    env: JOB_NAME=cmake
  - if: type = pull_request AND commit_message !~ /FULL_CI/ AND commit_message !~ /java/
    os : linux
    arch: arm64
@@ -32,10 +32,11 @@
 # 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")
@@ -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 ${GFLAGS_LIB})
@@ -210,7 +218,7 @@ if(MSVC)
  set(CMAKE_CXX_FLAGS "${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 "${CMAKE_CXX_FLAGS} -W -Wextra -Wall -pthread")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers -Wno-strict-aliasing")
  if(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64")
    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wstrict-prototypes")
@@ -296,6 +304,7 @@ else()
 endif()

 include(CheckCXXSourceCompiles)
+set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
 if(NOT MSVC)
  set(CMAKE_REQUIRED_FLAGS "-msse4.2 -mpclmul")
 endif()
@@ -312,7 +321,6 @@ int main() {
  auto d = _mm_cvtsi128_si64(c);
 }
 " HAVE_SSE42)
-unset(CMAKE_REQUIRED_FLAGS)
 if(HAVE_SSE42)
  add_definitions(-DHAVE_SSE42)
  add_definitions(-DHAVE_PCLMUL)
@@ -320,18 +328,66 @@ elseif(FORCE_SSE42)
  message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
 endif()

+# Check if -latomic is required or not
+if (NOT MSVC)
+  set(CMAKE_REQUIRED_FLAGS "--std=c++11")
+  CHECK_CXX_SOURCE_COMPILES("
+#include <atomic>
+std::atomic<uint64_t> x(0);
+int main() {
+  uint64_t i = x.load(std::memory_order_relaxed);
+  bool b = x.is_lock_free();
+  return 0;
+}
+" BUILTIN_ATOMIC)
+if (NOT BUILTIN_ATOMIC)
+  #TODO: Check if -latomic exists
+  list(APPEND THIRDPARTY_LIBS atomic)
+endif()
+endif()
+
+if (WITH_LIBURING)
+  set(CMAKE_REQUIRED_FLAGS "-luring")
+  CHECK_CXX_SOURCE_COMPILES("
+#include <liburing.h>
+int main() {
+  struct io_uring ring;
+  io_uring_queue_init(1, &ring, 0);
+  return 0;
+}
+" HAS_LIBURING)
+  if (HAS_LIBURING)
+    add_definitions(-DROCKSDB_IOURING_PRESENT)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -luring")
+  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()

+option(WITH_IOSTATS_CONTEXT "Enable IO stats context" ON)
+if (NOT WITH_IOSTATS_CONTEXT)
+  add_definitions(-DNIOSTATS_CONTEXT)
+endif()
+
+option(WITH_PERF_CONTEXT "Enable perf context" ON)
+if (NOT WITH_PERF_CONTEXT)
+  add_definitions(-DNPERF_CONTEXT)
+endif()
+
 option(FAIL_ON_WARNINGS "Treat compile warnings as errors" ON)
 if(FAIL_ON_WARNINGS)
  if(MSVC)
@@ -567,16 +623,20 @@ find_package(Threads REQUIRED)

 set(SOURCES
        cache/cache.cc
+        cache/cache_entry_roles.cc
+        cache/cache_reservation_manager.cc
        cache/clock_cache.cc
        cache/lru_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
@@ -653,6 +713,7 @@ set(SOURCES
        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
@@ -746,6 +807,7 @@ 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
@@ -757,9 +819,12 @@ 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
@@ -772,6 +837,7 @@ set(SOURCES
        util/random.cc
        util/rate_limiter.cc
        util/ribbon_config.cc
+        util/regex.cc
        util/slice.cc
        util/file_checksum_helper.cc
        util/status.cc
@@ -786,10 +852,13 @@ set(SOURCES
        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/debug.cc
        utilities/env_mirror.cc
@@ -798,6 +867,7 @@ set(SOURCES
        utilities/fault_injection_fs.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
@@ -817,6 +887,7 @@ 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
@@ -835,6 +906,7 @@ 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)

@@ -875,13 +947,8 @@ 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)
@@ -1063,23 +1130,28 @@ 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
+        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
@@ -1270,21 +1342,21 @@ 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}${ARTIFACT_SUFFIX})
+        gtest_discover_tests(${exename} DISCOVERY_TIMEOUT 120)
+        add_dependencies(check ${exename}${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)
+        target_link_libraries(${exename}${ARTIFACT_SUFFIX} rados)
      endif()
  endforeach(sourcefile ${TESTS})

@@ -1310,13 +1382,15 @@ 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})

@@ -1362,3 +1436,8 @@ 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()
@@ -1,9 +1,221 @@
 # Rocksdb Change Log
-## Unreleased
+## 6.26.0 (2021-10-20)
+### Bug Fixes
+* Fixes a bug in directed IO mode when calling MultiGet() for blobs in the same blob file. The bug is caused by not sorting the blob read requests by file offsets.
+* Fix the incorrect disabling of SST rate limited deletion when the WAL and DB are in different directories. Only WAL rate limited deletion should be disabled if its in a different directory.
+* Fix `DisableManualCompaction()` to cancel compactions even when they are waiting on automatic compactions to drain due to `CompactRangeOptions::exclusive_manual_compactions == true`.
+* Fix contract of `Env::ReopenWritableFile()` and `FileSystem::ReopenWritableFile()` to specify any existing file must not be deleted or truncated.
+* Fixed bug in calls to `IngestExternalFiles()` with files for multiple column families. The bug could have introduced a delay in ingested file keys becoming visible after `IngestExternalFiles()` returned. Furthermore, mutations to ingested file keys while they were invisible could have been dropped (not necessarily immediately).
+* Fixed a possible race condition impacting users of `WriteBufferManager` who constructed it with `allow_stall == true`. The race condition led to undefined behavior (in our experience, typically a process crash).
+* Fixed a bug where stalled writes would remain stalled forever after the user calls `WriteBufferManager::SetBufferSize()` with `new_size == 0` to dynamically disable memory limiting.
+* Make `DB::close()` thread-safe.
+* Fix a bug in atomic flush where one bg flush thread will wait forever for a preceding bg flush thread to commit its result to MANIFEST but encounters an error which is mapped to a soft error (DB not stopped).
+
+### New Features
+* Print information about blob files when using "ldb list_live_files_metadata"
+* Provided support for SingleDelete with user defined timestamp.
+* Experimental new function DB::GetLiveFilesStorageInfo offers essentially a unified version of other functions like GetLiveFiles, GetLiveFilesChecksumInfo, and GetSortedWalFiles. Checkpoints and backups could show small behavioral changes and/or improved performance as they now use this new API.
+* Add remote compaction read/write bytes statistics: `REMOTE_COMPACT_READ_BYTES`, `REMOTE_COMPACT_WRITE_BYTES`.
+* Introduce an experimental feature to dump out the blocks from block cache and insert them to the secondary cache to reduce the cache warmup time (e.g., used while migrating DB instance). More information are in `class CacheDumper` and `CacheDumpedLoader` at `rocksdb/utilities/cache_dump_load.h` Note that, this feature is subject to the potential change in the future, it is still experimental.
+* Introduced a new BlobDB configuration option `blob_garbage_collection_force_threshold`, which can be used to trigger compactions targeting the SST files which reference the oldest blob files when the ratio of garbage in those blob files meets or exceeds the specified threshold. This can reduce space amplification with skewed workloads where the affected SST files might not otherwise get picked up for compaction.
+* Added EXPERIMENTAL support for table file (SST) unique identifiers that are stable and universally unique, available with new function `GetUniqueIdFromTableProperties`. Only SST files from RocksDB >= 6.24 support unique IDs.
+* Added `GetMapProperty()` support for "rocksdb.dbstats" (`DB::Properties::kDBStats`). As a map property, it includes DB-level internal stats accumulated over the DB's lifetime, such as user write related stats and uptime.
+
+### Public API change
+* Made SystemClock extend the Customizable class and added a CreateFromString method.  Implementations need to be registered with the ObjectRegistry and to implement a Name() method in order to be created via this method.
+* Made SliceTransform extend the Customizable class and added a CreateFromString method.  Implementations need to be registered with the ObjectRegistry and to implement a Name() method in order to be created via this method.  The Capped and Prefixed transform classes return a short name (no length); use GetId for the fully qualified name.
+* Made FileChecksumGenFactory, SstPartitionerFactory, TablePropertiesCollectorFactory, and WalFilter extend the Customizable class and added a CreateFromString method.
+* Some fields of SstFileMetaData are deprecated for compatibility with new base class FileStorageInfo.
+* Add `file_temperature` to `IngestExternalFileArg` such that when ingesting SST files, we are able to indicate the temperature of the this batch of files.
+* If `DB::Close()` failed with a non aborted status, calling `DB::Close()` again will return the original status instead of Status::OK.
+* Add CacheTier to advanced_options.h to describe the cache tier we used. Add a `lowest_used_cache_tier` option to `DBOptions` (immutable) and pass it to BlockBasedTableReader. By default it is `CacheTier::kNonVolatileBlockTier`, which means, we always use both block cache (kVolatileTier) and secondary cache (kNonVolatileBlockTier). By set it to `CacheTier::kVolatileTier`, the DB will not use the secondary cache.
+* Even when options.max_compaction_bytes is hit, compaction output files are only cut when it aligns with grandparent files' boundaries. options.max_compaction_bytes could be slightly violated with the change, but the violation is no more than one target SST file size, which is usually much smaller.
+
+### Performance Improvements
+* Improved CPU efficiency of building block-based table (SST) files (#9039 and #9040).
+
+### Java API Changes
+* Add Java API bindings for new integrated BlobDB options
+* `keyMayExist()` supports ByteBuffer.
+* Fix multiget throwing Null Pointer Exception for num of keys > 70k (https://github.com/facebook/rocksdb/issues/8039).
+
+## 6.25.0 (2021-09-20)
+### Bug Fixes
+* Allow secondary instance to refresh iterator. Assign read seq after referencing SuperVersion.
+* Fixed a bug of secondary instance's last_sequence going backward, and reads on the secondary fail to see recent updates from the primary.
+* Fixed a bug that could lead to duplicate DB ID or DB session ID in POSIX environments without /proc/sys/kernel/random/uuid.
+* Fix a race in DumpStats() with column family destruction due to not taking a Ref on each entry while iterating the ColumnFamilySet.
+* Fix a race in item ref counting in LRUCache when promoting an item from the SecondaryCache.
+* Fix a race in BackupEngine if RateLimiter is reconfigured during concurrent Restore operations.
+* Fix a bug on POSIX in which failure to create a lock file (e.g. out of space) can prevent future LockFile attempts in the same process on the same file from succeeding.
+* Fix a bug that backup_rate_limiter and restore_rate_limiter in BackupEngine could not limit read rates.
+* Fix the implementation of `prepopulate_block_cache = kFlushOnly` to only apply to flushes rather than to all generated files.
+* Fix WAL log data corruption when using DBOptions.manual_wal_flush(true) and WriteOptions.sync(true) together. The sync WAL should work with locked log_write_mutex_.
+* Add checks for validity of the IO uring completion queue entries, and fail the BlockBasedTableReader MultiGet sub-batch if there's an invalid completion
+* Add an interface RocksDbIOUringEnable() that, if defined by the user, will allow them to enable/disable the use of IO uring by RocksDB
+* Fix the bug that when direct I/O is used and MultiRead() returns a short result, RandomAccessFileReader::MultiRead() still returns full size buffer, with returned short value together with some data in original buffer. This bug is unlikely cause incorrect results, because (1) since FileSystem layer is expected to retry on short result, returning short results is only possible when asking more bytes in the end of the file, which RocksDB doesn't do when using MultiRead(); (2) checksum is unlikely to match.
+
+### New Features
+* RemoteCompaction's interface now includes `db_name`, `db_id`, `session_id`, which could help the user uniquely identify compaction job between db instances and sessions.
+* Added a ticker statistic, "rocksdb.verify_checksum.read.bytes", reporting how many bytes were read from file to serve `VerifyChecksum()` and `VerifyFileChecksums()` queries.
+* Added ticker statistics, "rocksdb.backup.read.bytes" and "rocksdb.backup.write.bytes", reporting how many bytes were read and written during backup.
+* Added properties for BlobDB: `rocksdb.num-blob-files`, `rocksdb.blob-stats`, `rocksdb.total-blob-file-size`, and `rocksdb.live-blob-file-size`. The existing property `rocksdb.estimate_live-data-size` was also extended to include live bytes residing in blob files.
+* Added two new RateLimiter IOPriorities: `Env::IO_USER`,`Env::IO_MID`. `Env::IO_USER` will have superior priority over all other RateLimiter IOPriorities without being subject to fair scheduling constraint.
+* `SstFileWriter` now supports `Put`s and `Delete`s with user-defined timestamps. Note that the ingestion logic itself is not timestamp-aware yet.
+* Allow a single write batch to include keys from multiple column families whose timestamps' formats can differ. For example, some column families may disable timestamp, while others enable timestamp.
+* Add compaction priority information in RemoteCompaction, which can be used to schedule high priority job first.
+* Added new callback APIs `OnBlobFileCreationStarted`,`OnBlobFileCreated`and `OnBlobFileDeleted` in `EventListener` class of listener.h. It notifies listeners during creation/deletion of individual blob files in Integrated BlobDB. It also log blob file creation finished event and deletion event in LOG file.
+* Batch blob read requests for `DB::MultiGet` using `MultiRead`.
+* Add support for fallback to local compaction, the user can return `CompactionServiceJobStatus::kUseLocal` to instruct RocksDB to run the compaction locally instead of waiting for the remote compaction result.
+* Add built-in rate limiter's implementation of `RateLimiter::GetTotalPendingRequest(int64_t* total_pending_requests, const Env::IOPriority pri)` for the total number of requests that are pending for bytes in the rate limiter.
+* Charge memory usage during data buffering, from which training samples are gathered for dictionary compression, to block cache. Unbuffering data can now be triggered if the block cache becomes full and `strict_capacity_limit=true` for the block cache, in addition to existing conditions that can trigger unbuffering.
+
+### Public API change
+* Remove obsolete implementation details FullKey and ParseFullKey from public API
+* Change `SstFileMetaData::size` from `size_t` to `uint64_t`.
+* Made Statistics extend the Customizable class and added a CreateFromString method.  Implementations of Statistics need to be registered with the ObjectRegistry and to implement a Name() method in order to be created via this method.
+* Extended `FlushJobInfo` and `CompactionJobInfo` in listener.h to provide information about the blob files generated by a flush/compaction and garbage collected during compaction in Integrated BlobDB. Added struct members `blob_file_addition_infos` and `blob_file_garbage_infos` that contain this information.
+* Extended parameter `output_file_names` of `CompactFiles` API to also include paths of the blob files generated by the compaction in Integrated BlobDB.
+* Most `BackupEngine` functions now return `IOStatus` instead of `Status`. Most existing code should be compatible with this change but some calls might need to be updated.
+* Add a new field `level_at_creation` in `TablePropertiesCollectorFactory::Context` to capture the level at creating the SST file (i.e, table), of which the properties are being collected.
+
+### Miscellaneous
+* Add a paranoid check where in case FileSystem layer doesn't fill the buffer but returns succeed, checksum is unlikely to match even if buffer contains a previous block. The byte modified is not useful anyway, so it isn't expected to change any behavior when FileSystem is satisfying its contract.
+
+## 6.24.0 (2021-08-20)
+### Bug Fixes
+* If the primary's CURRENT file is missing or inaccessible, the secondary instance should not hang repeatedly trying to switch to a new MANIFEST. It should instead return the error code encountered while accessing the file.
+* Restoring backups with BackupEngine is now a logically atomic operation, so that if a restore operation is interrupted, DB::Open on it will fail. Using BackupEngineOptions::sync (default) ensures atomicity even in case of power loss or OS crash.
+* Fixed a race related to the destruction of `ColumnFamilyData` objects. The earlier logic unlocked the DB mutex before destroying the thread-local `SuperVersion` pointers, which could result in a process crash if another thread managed to get a reference to the `ColumnFamilyData` object.
+* Removed a call to `RenameFile()` on a non-existent info log file ("LOG") when opening a new DB. Such a call was guaranteed to fail though did not impact applications since we swallowed the error. Now we also stopped swallowing errors in renaming "LOG" file.
+* Fixed an issue where `OnFlushCompleted` was not called for atomic flush.
+* Fixed a bug affecting the batched `MultiGet` API when used with keys spanning multiple column families and `sorted_input == false`.
+* Fixed a potential incorrect result in opt mode and assertion failures caused by releasing snapshot(s) during compaction.
+* Fixed passing of BlobFileCompletionCallback to Compaction job and Atomic flush job which was default paramter (nullptr). BlobFileCompletitionCallback is internal callback that manages addition of blob files to SSTFileManager.
+* Fixed MultiGet not updating the block_read_count and block_read_byte PerfContext counters.
+
+### New Features
+* Made the EventListener extend the Customizable class.
+* EventListeners that have a non-empty Name() and that are registered with the ObjectRegistry can now be serialized to/from the OPTIONS file.
+* Insert warm blocks (data blocks, uncompressed dict blocks, index and filter blocks) in Block cache during flush under option BlockBasedTableOptions.prepopulate_block_cache. Previously it was enabled for only data blocks.
+* BlockBasedTableOptions.prepopulate_block_cache can be dynamically configured using DB::SetOptions.
+* Add CompactionOptionsFIFO.age_for_warm, which allows RocksDB to move old files to warm tier in FIFO compactions. Note that file temperature is still an experimental feature.
+* Add a comment to suggest btrfs user to disable file preallocation by setting `options.allow_fallocate=false`.
+* Fast forward option in Trace replay changed to double type to allow replaying at a lower speed, by settings the value between 0 and 1. This option can be set via `ReplayOptions` in `Replayer::Replay()`, or via `--trace_replay_fast_forward` in db_bench.
+* Add property `LiveSstFilesSizeAtTemperature` to retrieve sst file size at different temperature.
+* Added a stat rocksdb.secondary.cache.hits.
+* Added a PerfContext counter secondary_cache_hit_count.
+* The integrated BlobDB implementation now supports the tickers `BLOB_DB_BLOB_FILE_BYTES_READ`, `BLOB_DB_GC_NUM_KEYS_RELOCATED`, and `BLOB_DB_GC_BYTES_RELOCATED`, as well as the histograms `BLOB_DB_COMPRESSION_MICROS` and `BLOB_DB_DECOMPRESSION_MICROS`.
+* Added hybrid configuration of Ribbon filter and Bloom filter where some LSM levels use Ribbon for memory space efficiency and some use Bloom for speed. See NewRibbonFilterPolicy. This also changes the default behavior of NewRibbonFilterPolicy to use Bloom for flushes under Leveled and Universal compaction and Ribbon otherwise. The C API function `rocksdb_filterpolicy_create_ribbon` is unchanged but adds new `rocksdb_filterpolicy_create_ribbon_hybrid`.
+
+### Public API change
+* Added APIs to decode and replay trace file via Replayer class. Added `DB::NewDefaultReplayer()` to create a default Replayer instance. Added `TraceReader::Reset()` to restart reading a trace file. Created trace_record.h, trace_record_result.h and utilities/replayer.h files to access the decoded Trace records, replay them, and query the actual operation results.
+* Added Configurable::GetOptionsMap to the public API for use in creating new Customizable classes.
+* Generalized bits_per_key parameters in C API from int to double for greater configurability. Although this is a compatible change for existing C source code, anything depending on C API signatures, such as foreign function interfaces, will need to be updated.
+
+### Performance Improvements
+* Try to avoid updating DBOptions if `SetDBOptions()` does not change any option value.
+
+### Behavior Changes
+* `StringAppendOperator` additionally accepts a string as the delimiter.
+* BackupEngineOptions::sync (default true) now applies to restoring backups in addition to creating backups. This could slow down restores, but ensures they are fully persisted before returning OK. (Consider increasing max_background_operations to improve performance.)
+
+## 6.23.0 (2021-07-16)
+### Behavior Changes
+* Obsolete keys in the bottommost level that were preserved for a snapshot will now be cleaned upon snapshot release in all cases. This form of compaction (snapshot release triggered compaction) previously had an artificial limitation that multiple tombstones needed to be present.
+### Bug Fixes
+* Blob file checksums are now printed in hexadecimal format when using the `manifest_dump` `ldb` command.
+* `GetLiveFilesMetaData()` now populates the `temperature`, `oldest_ancester_time`, and `file_creation_time` fields of its `LiveFileMetaData` results when the information is available. Previously these fields always contained zero indicating unknown.
+* Fix mismatches of OnCompaction{Begin,Completed} in case of DisableManualCompaction().
+* Fix continuous logging of an existing background error on every user write
+* Fix a bug that `Get()` return Status::OK() and an empty value for non-existent key when `read_options.read_tier = kBlockCacheTier`.
+* Fix a bug that stat in `get_context` didn't accumulate to statistics when query is failed.
+* Fixed handling of DBOptions::wal_dir with LoadLatestOptions() or ldb --try_load_options on a copied or moved DB. Previously, when the WAL directory is same as DB directory (default), a copied or moved DB would reference the old path of the DB as the WAL directory, potentially corrupting both copies. Under this change, the wal_dir from DB::GetOptions() or LoadLatestOptions() may now be empty, indicating that the current DB directory is used for WALs. This is also a subtle API change.
+
+### New Features
+* ldb has a new feature, `list_live_files_metadata`, that shows the live SST files, as well as their LSM storage level and the column family they belong to.
+* The new BlobDB implementation now tracks the amount of garbage in each blob file in the MANIFEST.
+* Integrated BlobDB now supports Merge with base values (Put/Delete etc.).
+* RemoteCompaction supports sub-compaction, the job_id in the user interface is changed from `int` to `uint64_t` to support sub-compaction id.
+* Expose statistics option in RemoteCompaction worker.
+
+### Public API change
+* Added APIs to the Customizable class to allow developers to create their own Customizable classes.  Created the utilities/customizable_util.h file to contain helper methods for developing new Customizable classes.
+* Change signature of SecondaryCache::Name().  Make SecondaryCache customizable and add SecondaryCache::CreateFromString method.
+
+## 6.22.0 (2021-06-18)
+### Behavior Changes
+* Added two additional tickers, MEMTABLE_PAYLOAD_BYTES_AT_FLUSH and MEMTABLE_GARBAGE_BYTES_AT_FLUSH. These stats can be used to estimate the ratio of "garbage" (outdated) bytes in the memtable that are discarded at flush time.
+* Added API comments clarifying safe usage of Disable/EnableManualCompaction and EventListener callbacks for compaction.
+### Bug Fixes
+* fs_posix.cc GetFreeSpace() always report disk space available to root even when running as non-root.  Linux defaults often have disk mounts with 5 to 10 percent of total space reserved only for root.  Out of space could result for non-root users.
+* Subcompactions are now disabled when user-defined timestamps are used, since the subcompaction boundary picking logic is currently not timestamp-aware, which could lead to incorrect results when different subcompactions process keys that only differ by timestamp.
+* Fix an issue that `DeleteFilesInRange()` may cause ongoing compaction reports corruption exception, or ASSERT for debug build. There's no actual data loss or corruption that we find.
+* Fixed confusingly duplicated output in LOG for periodic stats ("DUMPING STATS"), including "Compaction Stats" and "File Read Latency Histogram By Level".
+* Fixed performance bugs in background gathering of block cache entry statistics, that could consume a lot of CPU when there are many column families with a shared block cache.
+
+### New Features
+* Marked the Ribbon filter and optimize_filters_for_memory features as production-ready, each enabling memory savings for Bloom-like filters. Use `NewRibbonFilterPolicy` in place of `NewBloomFilterPolicy` to use Ribbon filters instead of Bloom, or `ribbonfilter` in place of `bloomfilter` in configuration string.
+* Allow `DBWithTTL` to use `DeleteRange` api just like other DBs. `DeleteRangeCF()` which executes `WriteBatchInternal::DeleteRange()` has been added to the handler in `DBWithTTLImpl::Write()` to implement it.
+* Add BlockBasedTableOptions.prepopulate_block_cache.  If enabled, it prepopulate warm/hot data blocks which are already in memory into block cache at the time of flush. On a flush, the data block that is in memory (in memtables) get flushed to the device. If using Direct IO, additional IO is incurred to read this data back into memory again, which is avoided by enabling this option and it also helps with Distributed FileSystem. More details in include/rocksdb/table.h.
+* Added a `cancel` field to `CompactRangeOptions`, allowing individual in-process manual range compactions to be cancelled.
+
+### New Features
+* Added BlobMetaData to the ColumnFamilyMetaData to return information about blob files
+
+### Public API change
+* Added GetAllColumnFamilyMetaData API to retrieve the ColumnFamilyMetaData about all column families.
+
+## 6.21.0 (2021-05-21)
+### Bug Fixes
+* Fixed a bug in handling file rename error in distributed/network file systems when the server succeeds but client returns error. The bug can cause CURRENT file to point to non-existing MANIFEST file, thus DB cannot be opened.
+* Fixed a bug where ingested files were written with incorrect boundary key metadata. In rare cases this could have led to a level's files being wrongly ordered and queries for the boundary keys returning wrong results.
+* Fixed a data race between insertion into memtables and the retrieval of the DB properties `rocksdb.cur-size-active-mem-table`, `rocksdb.cur-size-all-mem-tables`, and `rocksdb.size-all-mem-tables`.
+* Fixed the false-positive alert when recovering from the WAL file. Avoid reporting "SST file is ahead of WAL" on a newly created empty column family, if the previous WAL file is corrupted.
+* Fixed a bug where `GetLiveFiles()` output included a non-existent file called "OPTIONS-000000". Backups and checkpoints, which use `GetLiveFiles()`, failed on DBs impacted by this bug. Read-write DBs were impacted when the latest OPTIONS file failed to write and `fail_if_options_file_error == false`. Read-only DBs were impacted when no OPTIONS files existed.
+* Handle return code by io_uring_submit_and_wait() and io_uring_wait_cqe().
+* In the IngestExternalFile() API, only try to sync the ingested file if the file is linked and the FileSystem/Env supports reopening a writable file.
+* Fixed a bug that `AdvancedColumnFamilyOptions.max_compaction_bytes` is under-calculated for manual compaction (`CompactRange()`). Manual compaction is split to multiple compactions if the compaction size exceed the `max_compaction_bytes`. The bug creates much larger compaction which size exceed the user setting. On the other hand, larger manual compaction size can increase the subcompaction parallelism, you can tune that by setting `max_compaction_bytes`.
+
+### Behavior Changes
+* Due to the fix of false-postive alert of "SST file is ahead of WAL", all the CFs with no SST file (CF empty) will bypass the consistency check. We fixed a false-positive, but introduced a very rare true-negative which will be triggered in the following conditions: A CF with some delete operations in the last a few queries which will result in an empty CF (those are flushed to SST file and a compaction triggered which combines this file and all other SST files and generates an empty CF, or there is another reason to write a manifest entry for this CF after a flush that generates no SST file from an empty CF). The deletion entries are logged in a WAL and this WAL was corrupted, while the CF's log number points to the next WAL (due to the flush). Therefore, the DB can only recover to the point without these trailing deletions and cause the inconsistent DB status.
+
+### New Features
+* Add new option allow_stall passed during instance creation of WriteBufferManager. When allow_stall is set, WriteBufferManager will stall all writers shared across multiple DBs and columns if memory usage goes beyond specified WriteBufferManager::buffer_size (soft limit). Stall will be cleared when memory is freed after flush and memory usage goes down below buffer_size.
+* Allow `CompactionFilter`s to apply in more table file creation scenarios such as flush and recovery. For compatibility, `CompactionFilter`s by default apply during compaction. Users can customize this behavior by overriding `CompactionFilterFactory::ShouldFilterTableFileCreation()`.
+* Added more fields to FilterBuildingContext with LSM details, for custom filter policies that vary behavior based on where they are in the LSM-tree.
+* Added DB::Properties::kBlockCacheEntryStats for querying statistics on what percentage of block cache is used by various kinds of blocks, etc. using DB::GetProperty and DB::GetMapProperty. The same information is now dumped to info LOG periodically according to `stats_dump_period_sec`.
+* Add an experimental Remote Compaction feature, which allows the user to run Compaction on a different host or process. The feature is still under development, currently only works on some basic use cases. The interface will be changed without backward/forward compatibility support.
+* RocksDB would validate total entries read in flush, and compare with counter inserted into it. If flush_verify_memtable_count = true (default), flush will fail. Otherwise, only log to info logs.
+* Add `TableProperties::num_filter_entries`, which can be used with `TableProperties::filter_size` to calculate the effective bits per filter entry (unique user key or prefix) for a table file.
+
+### Performance Improvements
+* BlockPrefetcher is used by iterators to prefetch data if they anticipate more data to be used in future. It is enabled implicitly by rocksdb. Added change to take in account read pattern if reads are sequential. This would disable prefetching for random reads in MultiGet and iterators as readahead_size is increased exponential doing large prefetches.
+
+### Public API change
+* Removed a parameter from TableFactory::NewTableBuilder, which should not be called by user code because TableBuilder is not a public API.
+* Removed unused structure `CompactionFilterContext`.
+* The `skip_filters` parameter to SstFileWriter is now considered deprecated. Use `BlockBasedTableOptions::filter_policy` to control generation of filters.
+* ClockCache is known to have bugs that could lead to crash or corruption, so should not be used until fixed. Use NewLRUCache instead.
+* Added a new pure virtual function `ApplyToAllEntries` to `Cache`, to replace `ApplyToAllCacheEntries`. Custom `Cache` implementations must add an implementation. Because this function is for gathering statistics, an empty implementation could be acceptable for some applications.
+* Added the ObjectRegistry to the ConfigOptions class.  This registry instance will be used to find any customizable loadable objects during initialization.
+* Expanded the ObjectRegistry functionality to allow nested ObjectRegistry instances.  Added methods to register a set of functions with the registry/library as a group.
+* Deprecated backupable_db.h and BackupableDBOptions in favor of new versions with appropriate names: backup_engine.h and BackupEngineOptions. Old API compatibility is preserved.
+
+### Default Option Change
+* When options.arena_block_size <= 0 (default value 0), still use writer_buffer_size / 8 but cap to 1MB. Too large alloation size might not be friendly to allocator and might cause performance issues in extreme cases.
+
+### Build
+* By default, try to build with liburing. For make, if ROCKSDB_USE_IO_URING is not set, treat as enable, which means RocksDB will try to build with liburing. Users can disable it with ROCKSDB_USE_IO_URING=0. For cmake, add WITH_LIBURING to control it, with default on.
+
+## 6.20.0 (2021-04-16)
 ### Behavior Changes
 * `ColumnFamilyOptions::sample_for_compression` now takes effect for creation of all block-based tables. Previously it only took effect for block-based tables created by flush.
 * `CompactFiles()` can no longer compact files from lower level to up level, which has the risk to corrupt DB (details: #8063). The validation is also added to all compactions.
 * Fixed some cases in which DB::OpenForReadOnly() could write to the filesystem. If you want a Logger with a read-only DB, you must now set DBOptions::info_log yourself, such as using CreateLoggerFromOptions().
+* get_iostats_context() will never return nullptr. If thread-local support is not available, and user does not opt-out iostats context, then compilation will fail. The same applies to perf context as well.
+* Added support for WriteBatchWithIndex::NewIteratorWithBase when overwrite_key=false.  Previously, this combination was not supported and would assert or return nullptr.
+* Improve the behavior of WriteBatchWithIndex for Merge operations.  Now more operations may be stored in order to return the correct merged result.

 ### Bug Fixes
 * Use thread-safe `strerror_r()` to get error messages.
@@ -11,6 +223,7 @@
 * Made BackupEngine thread-safe and added documentation comments to clarify what is safe for multiple BackupEngine objects accessing the same backup directory.
 * Fixed crash (divide by zero) when compression dictionary is applied to a file containing only range tombstones.
 * Fixed a backward iteration bug with partitioned filter enabled: not including the prefix of the last key of the previous filter partition in current filter partition can cause wrong iteration result.
+* Fixed a bug that allowed `DBOptions::max_open_files` to be set with a non-negative integer with `ColumnFamilyOptions::compaction_style = kCompactionStyleFIFO`.

 ### Performance Improvements
 * On ARM platform, use `yield` instead of `wfe` to relax cpu to gain better performance.
@@ -18,12 +231,17 @@
 ### Public API change
 * Added `TableProperties::slow_compression_estimated_data_size` and `TableProperties::fast_compression_estimated_data_size`. When `ColumnFamilyOptions::sample_for_compression > 0`, they estimate what `TableProperties::data_size` would have been if the "fast" or "slow" (see `ColumnFamilyOptions::sample_for_compression` API doc for definitions) compression had been used instead.
 * Update DB::StartIOTrace and remove Env object from the arguments as its redundant and DB already has Env object that is passed down to IOTracer::StartIOTrace
-* For new integrated BlobDB, add support for blob files for backup/restore like table files. Because of current limitations, blob files always use the kLegacyCrc32cAndFileSize naming scheme, and incremental backups must read and checksum all blob files in a DB, even for files that are already backed up.
+* Added `FlushReason::kWalFull`, which is reported when a memtable is flushed due to the WAL reaching its size limit; those flushes were previously reported as `FlushReason::kWriteBufferManager`. Also, changed the reason for flushes triggered by the write buffer manager to `FlushReason::kWriteBufferManager`; they were previously reported as `FlushReason::kWriteBufferFull`.
+* Extend file_checksum_dump ldb command and DB::GetLiveFilesChecksumInfo API for IntegratedBlobDB and get checksum of blob files along with SST files.

 ### New Features
 * Added the ability to open BackupEngine backups as read-only DBs, using BackupInfo::name_for_open and env_for_open provided by BackupEngine::GetBackupInfo() with include_file_details=true.
+* Added BackupEngine support for integrated BlobDB, with blob files shared between backups when table files are shared. Because of current limitations, blob files always use the kLegacyCrc32cAndFileSize naming scheme, and incremental backups must read and checksum all blob files in a DB, even for files that are already backed up.
+* Added an optional output parameter to BackupEngine::CreateNewBackup(WithMetadata) to return the BackupID of the new backup.
+* Added BackupEngine::GetBackupInfo / GetLatestBackupInfo for querying individual backups.
+* Made the Ribbon filter a long-term supported feature in terms of the SST schema(compatible with version >= 6.15.0) though the API for enabling it is expected to change.

-## 6.19.0 (03/21/2021)
+## 6.19.0 (2021-03-21)
 ### Bug Fixes
 * Fixed the truncation error found in APIs/tools when dumping block-based SST files in a human-readable format. After fix, the block-based table can be fully dumped as a readable file.
 * When hitting a write slowdown condition, no write delay (previously 1 millisecond) is imposed until `delayed_write_rate` is actually exceeded, with an initial burst allowance of 1 millisecond worth of bytes. Also, beyond the initial burst allowance, `delayed_write_rate` is now more strictly enforced, especially with multiple column families.
@@ -52,7 +270,7 @@
 ### Behavior Changes
 * During flush, only WAL sync retryable IO error is mapped to hard error, which will stall the writes. When WAL is used but only SST file write has retryable IO error, it will be mapped to soft error and write will not be affected.

-## 6.18.0 (02/19/2021)
+## 6.18.0 (2021-02-19)
 ### Behavior Changes
 * When retryable IO error occurs during compaction, it is mapped to soft error and set the BG error. However, auto resume is not called to clean the soft error since compaction will reschedule by itself. In this change, When retryable IO error occurs during compaction, BG error is not set. User will be informed the error via EventHelper.
 * Introduce a new trace file format for query tracing and replay and trace file version is bump up to 0.2. A payload map is added as the first portion of the payload. We will not have backward compatible issues when adding new entries to trace records. Added the iterator_upper_bound and iterator_lower_bound in Seek and SeekForPrev tracing function. Added them as the new payload member for iterator tracing.
@@ -76,7 +294,7 @@
 * Add an option, `CompressionOptions::max_dict_buffer_bytes`, to limit the in-memory buffering for selecting samples for generating/training a dictionary. The limit is currently loosely adhered to.


-## 6.17.0 (01/15/2021)
+## 6.17.0 (2021-01-15)
 ### Behavior Changes
 * When verifying full file checksum with `DB::VerifyFileChecksums()`, we now fail with `Status::InvalidArgument` if the name of the checksum generator used for verification does not match the name of the checksum generator used for protecting the file when it was created.
 * Since RocksDB does not continue write the same file if a file write fails for any reason, the file scope write IO error is treated the same as retryable IO error. More information about error handling of file scope IO error is included in `ErrorHandler::SetBGError`.
@@ -90,7 +308,7 @@
 * Add a SystemClock class that contains the time-related methods from Env.  The original methods in Env may be deprecated in a future release.  This class will allow easier testing, development, and expansion of time-related features.
 * Add a public API GetRocksBuildProperties and GetRocksBuildInfoAsString to get properties about the current build.  These properties may include settings related to the GIT settings (branch, timestamp).  This change also sets the "build date" based on the GIT properties, rather than the actual build time, thereby enabling more reproducible builds.

-## 6.16.0 (12/18/2020)
+## 6.16.0 (2020-12-18)
 ### Behavior Changes
 * Attempting to write a merge operand without explicitly configuring `merge_operator` now fails immediately, causing the DB to enter read-only mode. Previously, failure was deferred until the `merge_operator` was needed by a user read or a background operation.

@@ -116,7 +334,7 @@
 * `rocksdb_approximate_sizes` and `rocksdb_approximate_sizes_cf` in the C API now requires an error pointer (`char** errptr`) for receiving any error.
 * All overloads of DB::GetApproximateSizes now return Status, so that any failure to obtain the sizes is indicated to the caller.

-## 6.15.0 (11/13/2020)
+## 6.15.0 (2020-11-13)
 ### Bug Fixes
 * Fixed a bug in the following combination of features: indexes with user keys (`format_version >= 3`), indexes are partitioned (`index_type == kTwoLevelIndexSearch`), and some index partitions are pinned in memory (`BlockBasedTableOptions::pin_l0_filter_and_index_blocks_in_cache`). The bug could cause keys to be truncated when read from the index leading to wrong read results or other unexpected behavior.
 * Fixed a bug when indexes are partitioned (`index_type == kTwoLevelIndexSearch`), some index partitions are pinned in memory (`BlockBasedTableOptions::pin_l0_filter_and_index_blocks_in_cache`), and partitions reads could be mixed between block cache and directly from the file (e.g., with `enable_index_compression == 1` and `mmap_read == 1`, partitions that were stored uncompressed due to poor compression ratio would be read directly from the file via mmap, while partitions that were stored compressed would be read from block cache). The bug could cause index partitions to be mistakenly considered empty during reads leading to wrong read results.
@@ -144,7 +362,7 @@
 ### New Features
 * An EXPERIMENTAL new Bloom alternative that saves about 30% space compared to Bloom filters, with about 3-4x construction time and similar query times is available using NewExperimentalRibbonFilterPolicy.

-## 6.14 (10/09/2020)
+## 6.14 (2020-10-09)
 ### Bug fixes
 * Fixed a bug after a `CompactRange()` with `CompactRangeOptions::change_level` set fails due to a conflict in the level change step, which caused all subsequent calls to `CompactRange()` with `CompactRangeOptions::change_level` set to incorrectly fail with a `Status::NotSupported("another thread is refitting")` error.
 * Fixed a bug that the bottom most level compaction could still be a trivial move even if `BottommostLevelCompaction.kForce` or `kForceOptimized` is set.
@@ -168,7 +386,7 @@
 * SST files have a new table property called db_host_id, which is set to the hostname by default. A new option in DBOptions, db_host_id, allows the property value to be overridden with a user specified string, or disable it completely by making the option string empty.
 * Methods to create customizable extensions -- such as TableFactory -- are exposed directly through the Customizable base class (from which these objects inherit).  This change will allow these Customizable classes to be loaded and configured in a standard way (via CreateFromString).  More information on how to write and use Customizable classes is in the customizable.h header file.

-## 6.13 (09/12/2020)
+## 6.13 (2020-09-12)
 ### Bug fixes
 * Fix a performance regression introduced in 6.4 that makes a upper bound check for every Next() even if keys are within a data block that is within the upper bound.
 * Fix a possible corruption to the LSM state (overlapping files within a level) when a `CompactRange()` for refitting levels (`CompactRangeOptions::change_level == true`) and another manual compaction are executed in parallel.
@@ -248,7 +466,7 @@
 * Reduce key comparisons during random access in all block-based tables.
 * BackupEngine avoids unnecessary repeated checksum computation for backing up a table file to the `shared_checksum` directory when using `share_files_with_checksum_naming = kUseDbSessionId` (new default), except on SST files generated before this version of RocksDB, which fall back on using `kLegacyCrc32cAndFileSize`.

-## 6.11 (6/12/2020)
+## 6.11 (2020-06-12)
 ### Bug Fixes
 * Fix consistency checking error swallowing in some cases when options.force_consistency_checks = true.
 * Fix possible false NotFound status from batched MultiGet using index type kHashSearch.
@@ -283,7 +501,7 @@
 ### Performance Improvements
 * Eliminate redundant key comparisons during random access in block-based tables.

-## 6.10 (5/2/2020)
+## 6.10 (2020-05-02)
 ### Bug Fixes
 * Fix wrong result being read from ingested file. May happen when a key in the file happen to be prefix of another key also in the file. The issue can further cause more data corruption. The issue exists with rocksdb >= 5.0.0 since DB::IngestExternalFile() was introduced.
 * Finish implementation of BlockBasedTableOptions::IndexType::kBinarySearchWithFirstKey. It's now ready for use. Significantly reduces read amplification in some setups, especially for iterator seeks.
@@ -315,7 +533,7 @@
 * Improve performance of batch MultiGet with partitioned filters, by sharing block cache lookups to applicable filter blocks.
 * Reduced memory copies when fetching and uncompressing compressed blocks from sst files.

-## 6.9.0 (03/29/2020)
+## 6.9.0 (2020-03-29)
 ### Behavior changes
 * Since RocksDB 6.8, ttl-based FIFO compaction can drop a file whose oldest key becomes older than options.ttl while others have not. This fix reverts this and makes ttl-based FIFO compaction use the file's flush time as the criterion. This fix also requires that max_open_files = -1 and compaction_options_fifo.allow_compaction = false to function properly.

@@ -342,7 +560,7 @@
 * Added a new option, best_efforts_recovery (default: false), to allow database to open in a db dir with missing table files. During best efforts recovery, missing table files are ignored, and database recovers to the most recent state without missing table file. Cross-column-family consistency is not guaranteed even if WAL is enabled.
 * options.bottommost_compression, options.compression_opts and options.bottommost_compression_opts are now dynamically changeable.

-## 6.8.0 (02/24/2020)
+## 6.8.0 (2020-02-24)
 ### Java API Changes
 * Major breaking changes to Java comparators, toward standardizing on ByteBuffer for performant, locale-neutral operations on keys (#6252).
 * Added overloads of common API methods using direct ByteBuffers for keys and values (#2283).
@@ -369,7 +587,7 @@
 * `db_bench` now supports `value_size_distribution_type`, `value_size_min`, `value_size_max` options for generating random variable sized value. Added `blob_db_compression_type` option for BlobDB to enable blob compression.
 * Replace RocksDB namespace "rocksdb" with flag "ROCKSDB_NAMESPACE" which if is not defined, defined as "rocksdb" in header file rocksdb_namespace.h.

-## 6.7.0 (01/21/2020)
+## 6.7.0 (2020-01-21)
 ### Public API Change
 * Added a rocksdb::FileSystem class in include/rocksdb/file_system.h to encapsulate file creation/read/write operations, and an option DBOptions::file_system to allow a user to pass in an instance of rocksdb::FileSystem. If its a non-null value, this will take precendence over DBOptions::env for file operations. A new API rocksdb::FileSystem::Default() returns a platform default object. The DBOptions::env option and Env::Default() API will continue to be used for threading and other OS related functions, and where DBOptions::file_system is not specified, for file operations. For storage developers who are accustomed to rocksdb::Env, the interface in rocksdb::FileSystem is new and will probably undergo some changes as more storage systems are ported to it from rocksdb::Env. As of now, no env other than Posix has been ported to the new interface.
 * A new rocksdb::NewSstFileManager() API that allows the caller to pass in separate Env and FileSystem objects.
@@ -394,11 +612,11 @@
 * Introduce ReadOptions.auto_prefix_mode. When set to true, iterator will return the same result as total order seek, but may choose to use prefix seek internally based on seek key and iterator upper bound.
 * MultiGet() can use IO Uring to parallelize read from the same SST file. This featuer is by default disabled. It can be enabled with environment variable ROCKSDB_USE_IO_URING.

-## 6.6.2 (01/13/2020)
+## 6.6.2 (2020-01-13)
 ### Bug Fixes
 * Fixed a bug where non-L0 compaction input files were not considered to compute the `creation_time` of new compaction outputs.

-## 6.6.1 (01/02/2020)
+## 6.6.1 (2020-01-02)
 ### Bug Fixes
 * Fix a bug in WriteBatchWithIndex::MultiGetFromBatchAndDB, which is called by Transaction::MultiGet, that causes due to stale pointer access when the number of keys is > 32
 * Fixed two performance issues related to memtable history trimming. First, a new SuperVersion is now created only if some memtables were actually trimmed. Second, trimming is only scheduled if there is at least one flushed memtable that is kept in memory for the purposes of transaction conflict checking.
@@ -408,7 +626,7 @@
 * Delete superversions in BackgroundCallPurge.
 * Fix use-after-free and double-deleting files in BackgroundCallPurge().

-## 6.6.0 (11/25/2019)
+## 6.6.0 (2019-11-25)
 ### Bug Fixes
 * Fix data corruption caused by output of intra-L0 compaction on ingested file not being placed in correct order in L0.
 * Fix a data race between Version::GetColumnFamilyMetaData() and Compaction::MarkFilesBeingCompacted() for access to being_compacted (#6056). The current fix acquires the db mutex during Version::GetColumnFamilyMetaData(), which may cause regression.
@@ -461,19 +679,19 @@
 * For 64-bit hashing, RocksDB is standardizing on a slightly modified preview version of XXH3. This function is now used for many non-persisted hashes, along with fastrange64() in place of the modulus operator, and some benchmarks show a slight improvement.
 * Level iterator to invlidate the iterator more often in prefix seek and the level is filtered out by prefix bloom.

-## 6.5.2 (11/15/2019)
+## 6.5.2 (2019-11-15)
 ### Bug Fixes
 * Fix a assertion failure in MultiGet() when BlockBasedTableOptions::no_block_cache is true and there is no compressed block cache
 * Fix a buffer overrun problem in BlockBasedTable::MultiGet() when compression is enabled and no compressed block cache is configured.
 * If a call to BackupEngine::PurgeOldBackups or BackupEngine::DeleteBackup suffered a crash, power failure, or I/O error, files could be left over from old backups that could only be purged with a call to GarbageCollect. Any call to PurgeOldBackups, DeleteBackup, or GarbageCollect should now suffice to purge such files.

-## 6.5.1 (10/16/2019)
+## 6.5.1 (2019-10-16)
 ### Bug Fixes
 * Revert the feature "Merging iterator to avoid child iterator reseek for some cases (#5286)" since it might cause strange results when reseek happens with a different iterator upper bound.
 * Fix a bug in BlockBasedTableIterator that might return incorrect results when reseek happens with a different iterator upper bound.
 * Fix a bug when partitioned filters and prefix search are used in conjunction, ::SeekForPrev could return invalid for an existing prefix. ::SeekForPrev might be called by the user, or internally on ::Prev, or within ::Seek if the return value involves Delete or a Merge operand.

-## 6.5.0 (9/13/2019)
+## 6.5.0 (2019-09-13)
 ### Bug Fixes
 * Fixed a number of data races in BlobDB.
 * Fix a bug where the compaction snapshot refresh feature is not disabled as advertised when `snap_refresh_nanos` is set to 0..
@@ -494,7 +712,7 @@
 ### Performance Improvements
 * Improve the speed of the MemTable Bloom filter, reducing the write overhead of enabling it by 1/3 to 1/2, with similar benefit to read performance.

-## 6.4.0 (7/30/2019)
+## 6.4.0 (2019-07-30)
 ### Default Option Change
 * LRUCacheOptions.high_pri_pool_ratio is set to 0.5 (previously 0.0) by default, which means that by default midpoint insertion is enabled. The same change is made for the default value of high_pri_pool_ratio argument in NewLRUCache(). When block cache is not explicitly created, the small block cache created by BlockBasedTable will still has this option to be 0.0.
 * Change BlockBasedTableOptions.cache_index_and_filter_blocks_with_high_priority's default value from false to true.
@@ -530,7 +748,7 @@
 * Fixed a regression where the fill_cache read option also affected index blocks.
 * Fixed an issue where using cache_index_and_filter_blocks==false affected partitions of partitioned indexes/filters as well.

-## 6.3.2 (8/15/2019)
+## 6.3.2 (2019-08-15)
 ### Public API Change
 * The semantics of the per-block-type block read counts in the performance context now match those of the generic block_read_count.

@@ -538,11 +756,11 @@
 * Fixed a regression where the fill_cache read option also affected index blocks.
 * Fixed an issue where using cache_index_and_filter_blocks==false affected partitions of partitioned indexes as well.

-## 6.3.1 (7/24/2019)
+## 6.3.1 (2019-07-24)
 ### Bug Fixes
 * Fix auto rolling bug introduced in 6.3.0, which causes segfault if log file creation fails.

-## 6.3.0 (6/18/2019)
+## 6.3.0 (2019-06-18)
 ### Public API Change
 * Now DB::Close() will return Aborted() error when there is unreleased snapshot. Users can retry after all snapshots are released.
 * Index blocks are now handled similarly to data blocks with regards to the block cache: instead of storing objects in the cache, only the blocks themselves are cached. In addition, index blocks no longer get evicted from the cache when a table is closed, can now use the compressed block cache (if any), and can be shared among multiple table readers.
@@ -579,7 +797,7 @@
 * Fix a bug caused by secondary not skipping the beginning of new MANIFEST.
 * On DB open, delete WAL trash files left behind in wal_dir

-## 6.2.0 (4/30/2019)
+## 6.2.0 (2019-04-30)
 ### New Features
 * Add an option `strict_bytes_per_sync` that causes a file-writing thread to block rather than exceed the limit on bytes pending writeback specified by `bytes_per_sync` or `wal_bytes_per_sync`.
 * Improve range scan performance by avoiding per-key upper bound check in BlockBasedTableIterator.
@@ -601,7 +819,7 @@
 * Close a WAL file before another thread deletes it.
 * Fix an assertion failure `IsFlushPending() == true` caused by one bg thread releasing the db mutex in ~ColumnFamilyData and another thread clearing `flush_requested_` flag.

-## 6.1.1 (4/9/2019)
+## 6.1.1 (2019-04-09)
 ### New Features
 * When reading from option file/string/map, customized comparators and/or merge operators can be filled according to object registry.

@@ -611,7 +829,7 @@
 * Fix a bug in 2PC where a sequence of txn prepare, memtable flush, and crash could result in losing the prepared transaction.
 * Fix a bug in Encryption Env which could cause encrypted files to be read beyond file boundaries.

-## 6.1.0 (3/27/2019)
+## 6.1.0 (2019-03-27)
 ### New Features
 * Introduce two more stats levels, kExceptHistogramOrTimers and kExceptTimers.
 * Added a feature to perform data-block sampling for compressibility, and report stats to user.
@@ -629,7 +847,7 @@
 * Fix JEMALLOC_CXX_THROW macro missing from older Jemalloc versions, causing build failures on some platforms.
 * Fix SstFileReader not able to open file ingested with write_glbal_seqno=true.

-## 6.0.0 (2/19/2019)
+## 6.0.0 (2019-02-19)
 ### New Features
 * Enabled checkpoint on readonly db (DBImplReadOnly).
 * Make DB ignore dropped column families while committing results of atomic flush.
@@ -671,7 +889,7 @@
 ### Change Default Options
 * Change options.compaction_pri's default to kMinOverlappingRatio

-## 5.18.0 (11/30/2018)
+## 5.18.0 (2018-11-30)
 ### New Features
 * Introduced `JemallocNodumpAllocator` memory allocator. When being use, block cache will be excluded from core dump.
 * Introduced `PerfContextByLevel` as part of `PerfContext` which allows storing perf context at each level. Also replaced `__thread` with `thread_local` keyword for perf_context. Added per-level perf context for bloom filter and `Get` query.
@@ -699,7 +917,7 @@
 * Start populating `NO_FILE_CLOSES` ticker statistic, which was always zero previously.
 * The default value of NewBloomFilterPolicy()'s argument use_block_based_builder is changed to false. Note that this new default may cause large temp memory usage when building very large SST files.

-## 5.17.0 (10/05/2018)
+## 5.17.0 (2018-10-05)
 ### Public API Change
 * `OnTableFileCreated` will now be called for empty files generated during compaction. In that case, `TableFileCreationInfo::file_path` will be "(nil)" and `TableFileCreationInfo::file_size` will be zero.
 * Add `FlushOptions::allow_write_stall`, which controls whether Flush calls start working immediately, even if it causes user writes to stall, or will wait until flush can be performed without causing write stall (similar to `CompactRangeOptions::allow_write_stall`). Note that the default value is false, meaning we add delay to Flush calls until stalling can be avoided when possible. This is behavior change compared to previous RocksDB versions, where Flush calls didn't check if they might cause stall or not.
@@ -713,21 +931,21 @@
 * Avoid creating empty SSTs and subsequently deleting them in certain cases during compaction.
 * Sync CURRENT file contents during checkpoint.

-## 5.16.3 (10/1/2018)
+## 5.16.3 (2018-10-01)
 ### Bug Fixes
 * Fix crash caused when `CompactFiles` run with `CompactionOptions::compression == CompressionType::kDisableCompressionOption`. Now that setting causes the compression type to be chosen according to the column family-wide compression options.

-## 5.16.2 (9/21/2018)
+## 5.16.2 (2018-09-21)
 ### Bug Fixes
 * Fix bug in partition filters with format_version=4.

-## 5.16.1 (9/17/2018)
+## 5.16.1 (2018-09-17)
 ### Bug Fixes
 * Remove trace_analyzer_tool from rocksdb_lib target in TARGETS file.
 * Fix RocksDB Java build and tests.
 * Remove sync point in Block destructor.

-## 5.16.0 (8/21/2018)
+## 5.16.0 (2018-08-21)
 ### Public API Change
 * The merge operands are passed to `MergeOperator::ShouldMerge` in the reversed order relative to how they were merged (passed to FullMerge or FullMergeV2) for performance reasons
 * GetAllKeyVersions() to take an extra argument of `max_num_ikeys`.
@@ -741,7 +959,7 @@
 ### Bug Fixes
 * Fix a bug in misreporting the estimated partition index size in properties block.

-## 5.15.0 (7/17/2018)
+## 5.15.0 (2018-07-17)
 ### Public API Change
 * Remove managed iterator. ReadOptions.managed is not effective anymore.
 * For bottommost_compression, a compatible CompressionOptions is added via `bottommost_compression_opts`. To keep backward compatible, a new boolean `enabled` is added to CompressionOptions. For compression_opts, it will be always used no matter what value of `enabled` is. For bottommost_compression_opts, it will only be used when user set `enabled=true`, otherwise, compression_opts will be used for bottommost_compression as default.
@@ -767,7 +985,7 @@
 * Fix a bug caused by not copying the block trailer with compressed SST file, direct IO, prefetcher and no compressed block cache.
 * Fix write can stuck indefinitely if enable_pipelined_write=true. The issue exists since pipelined write was introduced in 5.5.0.

-## 5.14.0 (5/16/2018)
+## 5.14.0 (2018-05-16)
 ### Public API Change
 * Add a BlockBasedTableOption to align uncompressed data blocks on the smaller of block size or page size boundary, to reduce flash reads by avoiding reads spanning 4K pages.
 * The background thread naming convention changed (on supporting platforms) to "rocksdb:<thread pool priority><thread number>", e.g., "rocksdb:low0".
@@ -800,7 +1018,7 @@
 * Add `BlockBasedTableConfig.setBlockCache` to allow sharing a block cache across DB instances.
 * Added SstFileManager to the Java API to allow managing SST files across DB instances.

-## 5.13.0 (3/20/2018)
+## 5.13.0 (2018-03-20)
 ### Public API Change
 * RocksDBOptionsParser::Parse()'s `ignore_unknown_options` argument will only be effective if the option file shows it is generated using a higher version of RocksDB than the current version.
 * Remove CompactionEventListener.
@@ -816,7 +1034,7 @@
 * Fix a leak in prepared_section_completed_ where the zeroed entries would not removed from the map.
 * Fix WAL corruption caused by race condition between user write thread and backup/checkpoint thread.

-## 5.12.0 (2/14/2018)
+## 5.12.0 (2018-02-14)
 ### Public API Change
 * Iterator::SeekForPrev is now a pure virtual method. This is to prevent user who implement the Iterator interface fail to implement SeekForPrev by mistake.
 * Add `include_end` option to make the range end exclusive when `include_end == false` in `DeleteFilesInRange()`.
@@ -838,7 +1056,7 @@
 * Fix advance reservation of arena block addresses.
 * Fix handling of empty string as checkpoint directory.

-## 5.11.0 (01/08/2018)
+## 5.11.0 (2018-01-08)
 ### Public API Change
 * Add `autoTune` and `getBytesPerSecond()` to RocksJava RateLimiter

@@ -855,7 +1073,7 @@
 * Fix a mislabel bug for bottom-pri compaction threads.
 * Fix DB::Flush() keep waiting after flush finish under certain condition.

-## 5.10.0 (12/11/2017)
+## 5.10.0 (2017-12-11)
 ### Public API Change
 * When running `make` with environment variable `USE_SSE` set and `PORTABLE` unset, will use all machine features available locally. Previously this combination only compiled SSE-related features.

@@ -870,7 +1088,7 @@
 * Fix performance issue in `IngestExternalFile()` affecting databases with large number of SST files.
 * Fix possible corruption to LSM structure when `DeleteFilesInRange()` deletes a subset of files spanned by a `DeleteRange()` marker.

-## 5.9.0 (11/1/2017)
+## 5.9.0 (2017-11-01)
 ### Public API Change
 * `BackupableDBOptions::max_valid_backups_to_open == 0` now means no backups will be opened during BackupEngine initialization. Previously this condition disabled limiting backups opened.
 * `DBOptions::preserve_deletes` is a new option that allows one to specify that DB should not drop tombstones for regular deletes if they have sequence number larger than what was set by the new API call `DB::SetPreserveDeletesSequenceNumber(SequenceNumber seqnum)`. Disabled by default.
@@ -897,7 +1115,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Fix a potential data inconsistency issue during point-in-time recovery. `DB:Open()` will abort if column family inconsistency is found during PIT recovery.
 * Fix possible metadata corruption in databases using `DeleteRange()`.

-## 5.8.0 (08/30/2017)
+## 5.8.0 (2017-08-30)
 ### Public API Change
 * Users of `Statistics::getHistogramString()` will see fewer histogram buckets and different bucket endpoints.
 * `Slice::compare` and BytewiseComparator `Compare` no longer accept `Slice`s containing nullptr.
@@ -917,7 +1135,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Fix transient reappearance of keys covered by range deletions when memtable prefix bloom filter is enabled.
 * Fix potentially wrong file smallest key when range deletions separated by snapshot are written together.

-## 5.7.0 (07/13/2017)
+## 5.7.0 (2017-07-13)
 ### Public API Change
 * DB property "rocksdb.sstables" now prints keys in hex form.

@@ -932,7 +1150,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Bug Fixes
 * Fix discarding empty compaction output files when `DeleteRange()` is used together with subcompactions.

-## 5.6.0 (06/06/2017)
+## 5.6.0 (2017-06-06)
 ### Public API Change
 * Scheduling flushes and compactions in the same thread pool is no longer supported by setting `max_background_flushes=0`. Instead, users can achieve this by configuring their high-pri thread pool to have zero threads.
 * Replace `Options::max_background_flushes`, `Options::max_background_compactions`, and `Options::base_background_compactions` all with `Options::max_background_jobs`, which automatically decides how many threads to allocate towards flush/compaction.
@@ -949,7 +1167,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Bug Fixes
 * Shouldn't ignore return value of fsync() in flush.

-## 5.5.0 (05/17/2017)
+## 5.5.0 (2017-05-17)
 ### New Features
 * FIFO compaction to support Intra L0 compaction too with CompactionOptionsFIFO.allow_compaction=true.
 * DB::ResetStats() to reset internal stats.
@@ -966,7 +1184,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Bug Fixes
 * Fix the bug that Direct I/O uses direct reads for non-SST file

-## 5.4.0 (04/11/2017)
+## 5.4.0 (2017-04-11)
 ### Public API Change
 * random_access_max_buffer_size no longer has any effect
 * Removed Env::EnableReadAhead(), Env::ShouldForwardRawRequest()
@@ -983,7 +1201,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Introduce level-based L0->L0 compactions to reduce file count, so write delays are incurred less often.
 * (Experimental) Partitioning filters which creates an index on the partitions. The feature can be enabled by setting partition_filters when using kFullFilter. Currently the feature also requires two-level indexing to be enabled. Number of partitions is the same as the number of partitions for indexes, which is controlled by metadata_block_size.

-## 5.3.0 (03/08/2017)
+## 5.3.0 (2017-03-08)
 ### Public API Change
 * Remove disableDataSync option.
 * Remove timeout_hint_us option from WriteOptions. The option has been deprecated and has no effect since 3.13.0.
@@ -993,7 +1211,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Bug Fixes
 * Fix the bug that iterator may skip keys

-## 5.2.0 (02/08/2017)
+## 5.2.0 (2017-02-08)
 ### Public API Change
 * NewLRUCache() will determine number of shard bits automatically based on capacity, if the user doesn't pass one. This also impacts the default block cache when the user doesn't explicit provide one.
 * Change the default of delayed slowdown value to 16MB/s and further increase the L0 stop condition to 36 files.
@@ -1011,7 +1229,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Some fixes related to 2PC.
 * Fix bugs of data corruption in direct I/O

-## 5.1.0 (01/13/2017)
+## 5.1.0 (2017-01-13)
 * Support dynamically change `delete_obsolete_files_period_micros` option via SetDBOptions().
 * Added EventListener::OnExternalFileIngested which will be called when IngestExternalFile() add a file successfully.
 * BackupEngine::Open and BackupEngineReadOnly::Open now always return error statuses matching those of the backup Env.
@@ -1020,7 +1238,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Fix the bug that if 2PC is enabled, checkpoints may loss some recent transactions.
 * When file copying is needed when creating checkpoints or bulk loading files, fsync the file after the file copying.

-## 5.0.0 (11/17/2016)
+## 5.0.0 (2016-11-17)
 ### Public API Change
 * Options::max_bytes_for_level_multiplier is now a double along with all getters and setters.
 * Support dynamically change `delayed_write_rate` and `max_total_wal_size` options via SetDBOptions().
@@ -1039,7 +1257,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add LuaCompactionFilter in utilities.  This allows developers to write compaction filters in Lua.  To use this feature, LUA_PATH needs to be set to the root directory of Lua.
 * No longer populate "LATEST_BACKUP" file in backup directory, which formerly contained the number of the latest backup. The latest backup can be determined by finding the highest numbered file in the "meta/" subdirectory.

-## 4.13.0 (10/18/2016)
+## 4.13.0 (2016-10-18)
 ### Public API Change
 * DB::GetOptions() reflect dynamic changed options (i.e. through DB::SetOptions()) and return copy of options instead of reference.
 * Added Statistics::getAndResetTickerCount().
@@ -1048,7 +1266,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add DB::SetDBOptions() to dynamic change base_background_compactions and max_background_compactions.
 * Added Iterator::SeekForPrev(). This new API will seek to the last key that less than or equal to the target key.

-## 4.12.0 (9/12/2016)
+## 4.12.0 (2016-09-12)
 ### Public API Change
 * CancelAllBackgroundWork() flushes all memtables for databases containing writes that have bypassed the WAL (writes issued with WriteOptions::disableWAL=true) before shutting down background threads.
 * Merge options source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes.
@@ -1060,7 +1278,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Change ticker/histogram statistics implementations to accumulate data in thread-local storage, which improves CPU performance by reducing cache coherency costs. Callers of CreateDBStatistics do not need to change anything to use this feature.
 * Block cache mid-point insertion, where index and filter block are inserted into LRU block cache with higher priority. The feature can be enabled by setting BlockBasedTableOptions::cache_index_and_filter_blocks_with_high_priority to true and high_pri_pool_ratio > 0 when creating NewLRUCache.

-## 4.11.0 (8/1/2016)
+## 4.11.0 (2016-08-01)
 ### Public API Change
 * options.memtable_prefix_bloom_huge_page_tlb_size => memtable_huge_page_size. When it is set, RocksDB will try to allocate memory from huge page for memtable too, rather than just memtable bloom filter.

@@ -1068,7 +1286,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * A tool to migrate DB after options change. See include/rocksdb/utilities/option_change_migration.h.
 * Add ReadOptions.background_purge_on_iterator_cleanup. If true, we avoid file deletion when destroying iterators.

-## 4.10.0 (7/5/2016)
+## 4.10.0 (2016-07-05)
 ### Public API Change
 * options.memtable_prefix_bloom_bits changes to options.memtable_prefix_bloom_bits_ratio and deprecate options.memtable_prefix_bloom_probes
 * enum type CompressionType and PerfLevel changes from char to unsigned char. Value of all PerfLevel shift by one.
@@ -1080,7 +1298,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * RepairDB support for column families. RepairDB now associates data with non-default column families using information embedded in the SST/WAL files (4.7 or later). For data written by 4.6 or earlier, RepairDB associates it with the default column family.
 * Add options.write_buffer_manager which allows users to control total memtable sizes across multiple DB instances.

-## 4.9.0 (6/9/2016)
+## 4.9.0 (2016-06-09)
 ### Public API changes
 * Add bottommost_compression option, This option can be used to set a specific compression algorithm for the bottommost level (Last level containing files in the DB).
 * Introduce CompactionJobInfo::compression, This field state the compression algorithm used to generate the output files of the compaction.
@@ -1090,7 +1308,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### New Features
 * Introduce NewSimCache() in rocksdb/utilities/sim_cache.h. This function creates a block cache that is able to give simulation results (mainly hit rate) of simulating block behavior with a configurable cache size.

-## 4.8.0 (5/2/2016)
+## 4.8.0 (2016-05-02)
 ### Public API Change
 * Allow preset compression dictionary for improved compression of block-based tables. This is supported for zlib, zstd, and lz4. The compression dictionary's size is configurable via CompressionOptions::max_dict_bytes.
 * Delete deprecated classes for creating backups (BackupableDB) and restoring from backups (RestoreBackupableDB). Now, BackupEngine should be used for creating backups, and BackupEngineReadOnly should be used for restorations. For more details, see https://github.com/facebook/rocksdb/wiki/How-to-backup-RocksDB%3F
@@ -1100,12 +1318,12 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### New Features
 * Add ReadOptions::readahead_size. If non-zero, NewIterator will create a new table reader which performs reads of the given size.

-## 4.7.0 (4/8/2016)
+## 4.7.0 (2016-04-08)
 ### Public API Change
 * rename options compaction_measure_io_stats to report_bg_io_stats and include flush too.
 * Change some default options. Now default options will optimize for server-workloads. Also enable slowdown and full stop triggers for pending compaction bytes. These changes may cause sub-optimal performance or significant increase of resource usage. To avoid these risks, users can open existing RocksDB with options extracted from RocksDB option files. See https://github.com/facebook/rocksdb/wiki/RocksDB-Options-File for how to use RocksDB option files. Or you can call Options.OldDefaults() to recover old defaults. DEFAULT_OPTIONS_HISTORY.md will track change history of default options.

-## 4.6.0 (3/10/2016)
+## 4.6.0 (2016-03-10)
 ### Public API Changes
 * Change default of BlockBasedTableOptions.format_version to 2. It means default DB created by 4.6 or up cannot be opened by RocksDB version 3.9 or earlier.
 * Added strict_capacity_limit option to NewLRUCache. If the flag is set to true, insert to cache will fail if no enough capacity can be free. Signature of Cache::Insert() is updated accordingly.
@@ -1116,7 +1334,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add CompactionPri::kMinOverlappingRatio, a compaction picking mode friendly to write amplification.
 * Deprecate Iterator::IsKeyPinned() and replace it with Iterator::GetProperty() with prop_name="rocksdb.iterator.is.key.pinned"

-## 4.5.0 (2/5/2016)
+## 4.5.0 (2016-02-05)
 ### Public API Changes
 * Add a new perf context level between kEnableCount and kEnableTime. Level 2 now does not include timers for mutexes.
 * Statistics of mutex operation durations will not be measured by default. If you want to have them enabled, you need to set Statistics::stats_level_ to kAll.
@@ -1127,7 +1345,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add kPersistedTier to ReadTier.  This option allows Get and MultiGet to read only the persited data and skip mem-tables if writes were done with disableWAL = true.
 * Add DBOptions::sst_file_manager. Use NewSstFileManager() in include/rocksdb/sst_file_manager.h to create a SstFileManager that can be used to track the total size of SST files and control the SST files deletion rate.

-## 4.4.0 (1/14/2016)
+## 4.4.0 (2016-01-14)
 ### Public API Changes
 * Change names in CompactionPri and add a new one.
 * Deprecate options.soft_rate_limit and add options.soft_pending_compaction_bytes_limit.
@@ -1137,7 +1355,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Increase default options.delayed_write_rate to 2MB/s.
 * Added a new parameter --path to ldb tool. --path accepts the name of either MANIFEST, SST or a WAL file. Either --db or --path can be used when calling ldb.

-## 4.3.0 (12/8/2015)
+## 4.3.0 (2015-12-08)
 ### New Features
 * CompactionFilter has new member function called IgnoreSnapshots which allows CompactionFilter to be called even if there are snapshots later than the key.
 * RocksDB will now persist options under the same directory as the RocksDB database on successful DB::Open, CreateColumnFamily, DropColumnFamily, and SetOptions.
@@ -1147,7 +1365,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Public API Changes
 * When options.db_write_buffer_size triggers, only the column family with the largest column family size will be flushed, not all the column families.

-## 4.2.0 (11/9/2015)
+## 4.2.0 (2015-11-09)
 ### New Features
 * Introduce CreateLoggerFromOptions(), this function create a Logger for provided DBOptions.
 * Add GetAggregatedIntProperty(), which returns the sum of the GetIntProperty of all the column families.
@@ -1160,7 +1378,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Remove DefaultCompactionFilterFactory.


-## 4.1.0 (10/8/2015)
+## 4.1.0 (2015-10-08)
 ### New Features
 * Added single delete operation as a more efficient way to delete keys that have not been overwritten.
 * Added experimental AddFile() to DB interface that allow users to add files created by SstFileWriter into an empty Database, see include/rocksdb/sst_file_writer.h and DB::AddFile() for more info.
@@ -1174,7 +1392,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * CompactionFilter has a new method FilterMergeOperand() that RocksDB applies to every merge operand during compaction to decide whether to filter the operand.
 * We removed CompactionFilterV2 interfaces from include/rocksdb/compaction_filter.h. The functionality was deprecated already in version 3.13.

-## 4.0.0 (9/9/2015)
+## 4.0.0 (2015-09-09)
 ### New Features
 * Added support for transactions.  See include/rocksdb/utilities/transaction.h for more info.
 * DB::GetProperty() now accepts "rocksdb.aggregated-table-properties" and "rocksdb.aggregated-table-properties-at-levelN", in which case it returns aggregated table properties of the target column family, or the aggregated table properties of the specified level N if the "at-level" version is used.
@@ -1187,7 +1405,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Added Equal() method to the Comparator interface that can optionally be overwritten in cases where equality comparisons can be done more efficiently than three-way comparisons.
 * Previous 'experimental' OptimisticTransaction class has been replaced by Transaction class.

-## 3.13.0 (8/6/2015)
+## 3.13.0 (2015-08-06)
 ### New Features
 * RollbackToSavePoint() in WriteBatch/WriteBatchWithIndex
 * Add NewCompactOnDeletionCollectorFactory() in utilities/table_properties_collectors, which allows rocksdb to mark a SST file as need-compaction when it observes at least D deletion entries in any N consecutive entries in that SST file.  Note that this feature depends on an experimental NeedCompact() API --- the result of this API will not persist after DB restart.
@@ -1202,7 +1420,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add statistics::getHistogramString() to print detailed distribution of a histogram metric.
 * Add DBOptions::skip_stats_update_on_db_open.  When it is on, DB::Open() will run faster as it skips the random reads required for loading necessary stats from SST files to optimize compaction.

-## 3.12.0 (7/2/2015)
+## 3.12.0 (2015-07-02)
 ### New Features
 * Added experimental support for optimistic transactions.  See include/rocksdb/utilities/optimistic_transaction.h for more info.
 * Added a new way to report QPS from db_bench (check out --report_file and --report_interval_seconds)
@@ -1232,7 +1450,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add BackupEngineImpl.options_.max_background_operations to specify the maximum number of operations that may be performed in parallel. Add support for parallelized backup and restore.
 * Add DB::SyncWAL() that does a WAL sync without blocking writers.

-## 3.11.0 (5/19/2015)
+## 3.11.0 (2015-05-19)
 ### New Features
 * Added a new API Cache::SetCapacity(size_t capacity) to dynamically change the maximum configured capacity of the cache. If the new capacity is less than the existing cache usage, the implementation will try to lower the usage by evicting the necessary number of elements following a strict LRU policy.
 * Added an experimental API for handling flashcache devices (blacklists background threads from caching their reads) -- NewFlashcacheAwareEnv
@@ -1243,7 +1461,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * TablePropertiesCollector::AddUserKey() is added to replace TablePropertiesCollector::Add(). AddUserKey() exposes key type, sequence number and file size up to now to users.
 * DBOptions::bytes_per_sync used to apply to both WAL and table files. As of 3.11 it applies only to table files. If you want to use this option to sync WAL in the background, please use wal_bytes_per_sync

-## 3.10.0 (3/24/2015)
+## 3.10.0 (2015-03-24)
 ### New Features
 * GetThreadStatus() is now able to report detailed thread status, including:
 - Thread Operation including flush and compaction.
@@ -1278,7 +1496,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * lz4 compression is now included in rocksjava static library when running `make rocksdbjavastatic`.
 * Overflowing a size_t when setting rocksdb options now throws an IllegalArgumentException, which removes the necessity for a developer to catch these Exceptions explicitly.

-## 3.9.0 (12/8/2014)
+## 3.9.0 (2014-12-08)

 ### New Features
 * Add rocksdb::GetThreadList(), which in the future will return the current status of all
@@ -1297,7 +1515,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Improvements
 * RocksDBLite library now becomes smaller and will be compiled with -fno-exceptions flag.

-## 3.8.0 (11/14/2014)
+## 3.8.0 (2014-11-14)

 ### Public API changes
 * BackupEngine::NewBackupEngine() was deprecated; please use BackupEngine::Open() from now on.
@@ -1311,14 +1529,14 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * CompactFiles and EventListener, although they are still in experimental state
 * Full ColumnFamily support in RocksJava.

-## 3.7.0 (11/6/2014)
+## 3.7.0 (2014-11-06)
 ### Public API changes
 * Introduce SetOptions() API to allow adjusting a subset of options dynamically online
 * Introduce 4 new convenient functions for converting Options from string: GetColumnFamilyOptionsFromMap(), GetColumnFamilyOptionsFromString(), GetDBOptionsFromMap(), GetDBOptionsFromString()
 * Remove WriteBatchWithIndex.Delete() overloads using SliceParts
 * When opening a DB, if options.max_background_compactions is larger than the existing low pri pool of options.env, it will enlarge it. Similarly, options.max_background_flushes is larger than the existing high pri pool of options.env, it will enlarge it.

-## 3.6.0 (10/7/2014)
+## 3.6.0 (2014-10-07)
 ### Disk format changes
 * If you're using RocksDB on ARM platforms and you're using default bloom filter, there is a disk format change you need to be aware of. There are three steps you need to do when you convert to new release: 1. turn off filter policy, 2. compact the whole database, 3. turn on filter policy

@@ -1331,7 +1549,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Change target_file_size_base type to uint64_t from int.
 * Remove allow_thread_local. This feature was proved to be stable, so we are turning it always-on.

-## 3.5.0 (9/3/2014)
+## 3.5.0 (2014-09-03)
 ### New Features
 * Add include/utilities/write_batch_with_index.h, providing a utility class to query data out of WriteBatch when building it.
 * Move BlockBasedTable related options to BlockBasedTableOptions from Options. Change corresponding JNI interface. Options affected include:
@@ -1342,7 +1560,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Public API changes
 * The Prefix Extractor used with V2 compaction filters is now passed user key to SliceTransform::Transform instead of unparsed RocksDB key.

-## 3.4.0 (8/18/2014)
+## 3.4.0 (2014-08-18)
 ### New Features
 * Support Multiple DB paths in universal style compactions
 * Add feature of storing plain table index and bloom filter in SST file.
@@ -1358,7 +1576,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 * Add DB::GetIntProperty(), which returns DB properties that are integer as uint64_t.
 * The Prefix Extractor used with V2 compaction filters is now passed user key to SliceTransform::Transform instead of unparsed RocksDB key.

-## 3.3.0 (7/10/2014)
+## 3.3.0 (2014-07-10)
 ### New Features
 * Added JSON API prototype.
 * HashLinklist reduces performance outlier caused by skewed bucket by switching data in the bucket from linked list to skip list. Add parameter threshold_use_skiplist in NewHashLinkListRepFactory().
@@ -1369,7 +1587,7 @@ if set to something > 0 user will see 2 changes in iterators behavior 1) only ke
 ### Public API changes
 * Removed NewTotalOrderPlainTableFactory because it is not used and implemented semantically incorrect.

-## 3.2.0 (06/20/2014)
+## 3.2.0 (2014-06-20)

 ### Public API changes
 * We removed seek compaction as a concept from RocksDB because:
@@ -1387,7 +1605,7 @@ Because of that, Options::disable_seek_compaction is now obsolete. It is still a
 ### Performance Improvements
 * Tailing Iterator re-implemeted with ForwardIterator + Cascading Search Hint , see ~20% throughput improvement.

-## 3.1.0 (05/21/2014)
+## 3.1.0 (2014-05-21)

 ### Public API changes
 * Replaced ColumnFamilyOptions::table_properties_collectors with ColumnFamilyOptions::table_properties_collector_factories
@@ -1396,7 +1614,7 @@ Because of that, Options::disable_seek_compaction is now obsolete. It is still a
 * Hash index for block-based table will be materialized and reconstructed more efficiently. Previously hash index is constructed by scanning the whole table during every table open.
 * FIFO compaction style

-## 3.0.0 (05/05/2014)
+## 3.0.0 (2014-05-05)

 ### Public API changes
 * Added _LEVEL to all InfoLogLevel enums
@@ -1408,7 +1626,7 @@ Because of that, Options::disable_seek_compaction is now obsolete. It is still a
 * Added an option to use different checksum functions in BlockBasedTableOptions
 * Added ApplyToAllCacheEntries() function to Cache

-## 2.8.0 (04/04/2014)
+## 2.8.0 (2014-04-04)

 * Removed arena.h from public header files.
 * By default, checksums are verified on every read from database
@@ -1437,7 +1655,7 @@ Because of that, Options::disable_seek_compaction is now obsolete. It is still a
 * Now compaction filter has a V2 interface. It buffers the kv-pairs sharing the same key prefix, process them in batches, and return the batched results back to DB. The new interface uses a new structure CompactionFilterContext for the same purpose as CompactionFilter::Context in V1.
 * Geo-spatial support for locations and radial-search.

-## 2.7.0 (01/28/2014)
+## 2.7.0 (2014-01-28)

 ### Public API changes

@@ -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)
@@ -55,50 +55,25 @@ DEBUG_LEVEL?=1
 # Set the default LIB_MODE to static
 LIB_MODE?=static

-ifeq ($(MAKECMDGOALS),dbg)
+# OBJ_DIR is where the object files reside.  Default to the current directory
+OBJ_DIR?=.
+
+# Check the MAKECMDGOALS to set the DEBUG_LEVEL and LIB_MODE appropriately
+
+ifneq ($(filter clean release install, $(MAKECMDGOALS)),)
+	DEBUG_LEVEL=0
+endif
+ifneq ($(filter dbg, $(MAKECMDGOALS)),)
 	DEBUG_LEVEL=2
-endif
-
-ifeq ($(MAKECMDGOALS),clean)
+else ifneq ($(filter shared_lib install-shared, $(MAKECMDGOALS)),)
 	DEBUG_LEVEL=0
-endif
-
-ifeq ($(MAKECMDGOALS),release)
-	DEBUG_LEVEL=0
-endif
-
-ifeq ($(MAKECMDGOALS),shared_lib)
 	LIB_MODE=shared
-	DEBUG_LEVEL=0
-endif
-
-ifeq ($(MAKECMDGOALS),install-shared)
-	LIB_MODE=shared
-	DEBUG_LEVEL=0
-endif
-
-ifeq ($(MAKECMDGOALS),static_lib)
+else ifneq ($(filter static_lib install-static, $(MAKECMDGOALS)),)
 	DEBUG_LEVEL=0
 	LIB_MODE=static
-endif
-
-ifeq ($(MAKECMDGOALS),install-static)
-	DEBUG_LEVEL=0
-	LIB_MODE=static
-endif
-
-ifeq ($(MAKECMDGOALS),install)
-	DEBUG_LEVEL=0
-endif
-
-
-ifneq ($(findstring jtest, $(MAKECMDGOALS)),)
+else ifneq ($(filter jtest rocksdbjava%, $(MAKECMDGOALS)),)
 	OBJ_DIR=jl
 	LIB_MODE=shared
-endif
-
-ifneq ($(findstring rocksdbjava, $(MAKECMDGOALS)),)
-	LIB_MODE=shared
 	ifneq ($(findstring rocksdbjavastatic, $(MAKECMDGOALS)),)
 		OBJ_DIR=jls
 		ifneq ($(DEBUG_LEVEL),2)
@@ -107,8 +82,6 @@ ifneq ($(findstring rocksdbjava, $(MAKECMDGOALS)),)
 		ifeq ($(MAKECMDGOALS),rocksdbjavastaticpublish)
 			DEBUG_LEVEL=0
 		endif
-	else
-		OBJ_DIR=jl
 	endif
 endif

@@ -371,6 +344,12 @@ 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
@@ -491,7 +470,6 @@ CXXFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverl

 LDFLAGS += $(PLATFORM_LDFLAGS)

-OBJ_DIR?=.
 LIB_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(LIB_SOURCES))
 LIB_OBJECTS += $(patsubst %.cc, $(OBJ_DIR)/%.o, $(ROCKSDB_PLUGIN_SOURCES))
 ifeq ($(HAVE_POWER8),1)
@@ -516,16 +494,18 @@ 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)

 TESTS = $(patsubst %.cc, %, $(notdir $(TEST_MAIN_SOURCES)))
@@ -536,6 +516,29 @@ ifeq ($(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/ hdfs/ $(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/|tools/rdb/db_wrapper.h|include/rocksdb/utilities/env_librados.h')
+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')
@@ -543,8 +546,9 @@ endif
 ifdef ASSERT_STATUS_CHECKED
 	# TODO: finish fixing all tests to pass this check
 	TESTS_FAILING_ASC = \
+		c_test \
 		db_test \
-		db_test2 \
+		env_test \
 		range_locking_test \
 		testutil_test \

@@ -620,6 +624,8 @@ 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
@@ -651,8 +657,8 @@ else
 LIBRARY=$(STATIC_LIBRARY)
 TEST_LIBRARY=$(STATIC_TEST_LIBRARY)
 TOOLS_LIBRARY=$(STATIC_TOOLS_LIBRARY)
-STRESS_LIBRARY=$(STATIC_STRESS_LIBRARY)
 endif
+STRESS_LIBRARY=$(STATIC_STRESS_LIBRARY)

 ROCKSDB_MAJOR = $(shell egrep "ROCKSDB_MAJOR.[0-9]" include/rocksdb/version.h | cut -d ' ' -f 3)
 ROCKSDB_MINOR = $(shell egrep "ROCKSDB_MINOR.[0-9]" include/rocksdb/version.h | cut -d ' ' -f 3)
@@ -733,7 +739,7 @@ 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 \
@@ -758,6 +764,9 @@ test_libs: $(TEST_LIBS)

 benchmarks: $(BENCHMARKS)

+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
@@ -957,6 +966,7 @@ endif
 ifndef SKIP_FORMAT_BUCK_CHECKS
 	$(MAKE) check-format
 	$(MAKE) check-buck-targets
+	$(MAKE) check-sources
 endif

 # TODO add ldb_tests
@@ -1071,6 +1081,12 @@ 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

@@ -1189,7 +1205,7 @@ 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 {} \;
@@ -1228,6 +1244,9 @@ 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)

@@ -1246,7 +1265,7 @@ $(STATIC_TOOLS_LIBRARY): $(TOOL_OBJECTS)
 	$(AM_V_AR)rm -f $@ $(SHARED_TOOLS_LIBRARY)
 	$(AM_V_at)$(AR) $(ARFLAGS) $@ $^

-$(STATIC_STRESS_LIBRARY): $(ANALYZE_OBJECTS) $(STRESS_OBJECTS)
+$(STATIC_STRESS_LIBRARY): $(ANALYZE_OBJECTS) $(STRESS_OBJECTS) $(TESTUTIL)
 	$(AM_V_AR)rm -f $@ $(SHARED_STRESS_LIBRARY)
 	$(AM_V_at)$(AR) $(ARFLAGS) $@ $^

@@ -1258,7 +1277,7 @@ $(SHARED_TOOLS_LIBRARY): $(TOOL_OBJECTS) $(SHARED1)
 	$(AM_V_AR)rm -f $@ $(STATIC_TOOLS_LIBRARY)
 	$(AM_SHARE)

-$(SHARED_STRESS_LIBRARY): $(ANALYZE_OBJECTS) $(STRESS_OBJECTS) $(SHARED_TOOLS_LIBRARY) $(SHARED1)
+$(SHARED_STRESS_LIBRARY): $(ANALYZE_OBJECTS) $(STRESS_OBJECTS) $(TESTUTIL) $(SHARED_TOOLS_LIBRARY) $(SHARED1)
 	$(AM_V_AR)rm -f $@ $(STATIC_STRESS_LIBRARY)
 	$(AM_SHARE)

@@ -1280,7 +1299,7 @@ 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)
@@ -1292,7 +1311,7 @@ memtablerep_bench: $(OBJ_DIR)/memtable/memtablerep_bench.o $(LIBRARY)
 filter_bench: $(OBJ_DIR)/util/filter_bench.o $(LIBRARY)
 	$(AM_LINK)

-db_stress: $(OBJ_DIR)/db_stress_tool/db_stress.o $(STRESS_LIBRARY) $(TOOLS_LIBRARY) $(TESTUTIL) $(LIBRARY)
+db_stress: $(OBJ_DIR)/db_stress_tool/db_stress.o $(STRESS_LIBRARY) $(TOOLS_LIBRARY) $(LIBRARY)
 	$(AM_LINK)

 write_stress: $(OBJ_DIR)/tools/write_stress.o $(LIBRARY)
@@ -1567,6 +1586,9 @@ 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)

@@ -1849,6 +1871,9 @@ 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)

@@ -1864,6 +1889,9 @@ 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)

@@ -1887,6 +1915,18 @@ io_tracer_parser: $(OBJ_DIR)/tools/io_tracer_parser.o $(TOOLS_LIBRARY) $(LIBRARY

 db_blob_corruption_test: $(OBJ_DIR)/db/blob/db_blob_corruption_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
+
+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)
+
+cache_reservation_manager_test: $(OBJ_DIR)/cache/cache_reservation_manager_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
 #-------------------------------------------------
 # make install related stuff
 PREFIX ?= /usr/local
@@ -1994,7 +2034,7 @@ ZLIB_SHA256 ?= c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1
 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
@@ -2351,7 +2391,7 @@ build_subset_tests: $(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
@@ -1,3 +1,4 @@
 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
+* [ZenFS](https://github.com/westerndigitalcorporation/zenfs): a file system for zoned block devices
@@ -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.

@@ -10,7 +10,7 @@ load(":defs.bzl", "test_binary")

 REPO_PATH = package_name() + "/"

-ROCKSDB_COMPILER_FLAGS = [
+ROCKSDB_COMPILER_FLAGS_0 = [
    "-fno-builtin-memcmp",
    # Needed to compile in fbcode
    "-Wno-expansion-to-defined",
@@ -28,7 +28,7 @@ ROCKSDB_EXTERNAL_DEPS = [
    ("zstd", None, "zstd"),
 ]

-ROCKSDB_OS_DEPS = [
+ROCKSDB_OS_DEPS_0 = [
    (
        "linux",
        ["third-party//numa:numa", "third-party//liburing:uring", "third-party//tbb:tbb"],
@@ -39,7 +39,7 @@ ROCKSDB_OS_DEPS = [
    ),
 ]

-ROCKSDB_OS_PREPROCESSOR_FLAGS = [
+ROCKSDB_OS_PREPROCESSOR_FLAGS_0 = [
    (
        "linux",
        [
@@ -107,18 +107,18 @@ 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 [])
+ROCKSDB_COMPILER_FLAGS = ROCKSDB_COMPILER_FLAGS_0 + (["-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 += ([(
+ROCKSDB_OS_PREPROCESSOR_FLAGS = ROCKSDB_OS_PREPROCESSOR_FLAGS_0 + ([(
    "linux",
    ["-DROCKSDB_JEMALLOC"],
 )] if sanitizer == "" else [])

-ROCKSDB_OS_DEPS += ([(
+ROCKSDB_OS_DEPS = ROCKSDB_OS_DEPS_0 + ([(
    "linux",
    ["third-party//jemalloc:headers"],
 )] if sanitizer == "" else [])
@@ -132,16 +132,20 @@ cpp_library(
    name = "rocksdb_lib",
    srcs = [
        "cache/cache.cc",
+        "cache/cache_entry_roles.cc",
+        "cache/cache_reservation_manager.cc",
        "cache/clock_cache.cc",
        "cache/lru_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",
@@ -221,6 +225,7 @@ cpp_library(
        "env/fs_remap.cc",
        "env/io_posix.cc",
        "env/mock_env.cc",
+        "env/unique_id_gen.cc",
        "file/delete_scheduler.cc",
        "file/file_prefetch_buffer.cc",
        "file/file_util.cc",
@@ -322,6 +327,7 @@ cpp_library(
        "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/transaction_test_util.cc",
@@ -332,6 +338,9 @@ cpp_library(
        "tools/sst_dump_tool.cc",
        "trace_replay/block_cache_tracer.cc",
        "trace_replay/io_tracer.cc",
+        "trace_replay/trace_record.cc",
+        "trace_replay/trace_record_handler.cc",
+        "trace_replay/trace_record_result.cc",
        "trace_replay/trace_replay.cc",
        "util/build_version.cc",
        "util/coding.cc",
@@ -340,12 +349,14 @@ cpp_library(
        "util/compression_context_cache.cc",
        "util/concurrent_task_limiter_impl.cc",
        "util/crc32c.cc",
+        "util/crc32c_arm64.cc",
        "util/dynamic_bloom.cc",
        "util/file_checksum_helper.cc",
        "util/hash.cc",
        "util/murmurhash.cc",
        "util/random.cc",
        "util/rate_limiter.cc",
+        "util/regex.cc",
        "util/ribbon_config.cc",
        "util/slice.cc",
        "util/status.cc",
@@ -360,10 +371,13 @@ cpp_library(
        "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/convenience/info_log_finder.cc",
        "utilities/debug.cc",
@@ -373,6 +387,7 @@ cpp_library(
        "utilities/fault_injection_fs.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",
@@ -392,6 +407,7 @@ cpp_library(
        "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_manager.cc",
        "utilities/transactions/lock/point/point_lock_tracker.cc",
@@ -422,6 +438,7 @@ cpp_library(
        "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",
    ],
@@ -441,16 +458,20 @@ cpp_library(
    name = "rocksdb_whole_archive_lib",
    srcs = [
        "cache/cache.cc",
+        "cache/cache_entry_roles.cc",
+        "cache/cache_reservation_manager.cc",
        "cache/clock_cache.cc",
        "cache/lru_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",
@@ -530,6 +551,7 @@ cpp_library(
        "env/fs_remap.cc",
        "env/io_posix.cc",
        "env/mock_env.cc",
+        "env/unique_id_gen.cc",
        "file/delete_scheduler.cc",
        "file/file_prefetch_buffer.cc",
        "file/file_util.cc",
@@ -631,6 +653,7 @@ cpp_library(
        "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/transaction_test_util.cc",
@@ -641,6 +664,9 @@ cpp_library(
        "tools/sst_dump_tool.cc",
        "trace_replay/block_cache_tracer.cc",
        "trace_replay/io_tracer.cc",
+        "trace_replay/trace_record.cc",
+        "trace_replay/trace_record_handler.cc",
+        "trace_replay/trace_record_result.cc",
        "trace_replay/trace_replay.cc",
        "util/build_version.cc",
        "util/coding.cc",
@@ -649,12 +675,14 @@ cpp_library(
        "util/compression_context_cache.cc",
        "util/concurrent_task_limiter_impl.cc",
        "util/crc32c.cc",
+        "util/crc32c_arm64.cc",
        "util/dynamic_bloom.cc",
        "util/file_checksum_helper.cc",
        "util/hash.cc",
        "util/murmurhash.cc",
        "util/random.cc",
        "util/rate_limiter.cc",
+        "util/regex.cc",
        "util/ribbon_config.cc",
        "util/slice.cc",
        "util/status.cc",
@@ -669,10 +697,13 @@ cpp_library(
        "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/convenience/info_log_finder.cc",
        "utilities/debug.cc",
@@ -682,6 +713,7 @@ cpp_library(
        "utilities/fault_injection_fs.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",
@@ -701,6 +733,7 @@ cpp_library(
        "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_manager.cc",
        "utilities/transactions/lock/point/point_lock_tracker.cc",
@@ -731,6 +764,7 @@ cpp_library(
        "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",
    ],
@@ -778,6 +812,7 @@ cpp_library(
        "test_util/testutil.cc",
        "tools/block_cache_analyzer/block_cache_trace_analyzer.cc",
        "tools/db_bench_tool.cc",
+        "tools/simulated_hybrid_file_system.cc",
        "tools/trace_analyzer_tool.cc",
    ],
    auto_headers = AutoHeaders.RECURSIVE_GLOB,
@@ -792,6 +827,21 @@ cpp_library(
    link_whole = False,
 )

+cpp_library(
+    name = "rocksdb_cache_bench_tools_lib",
+    srcs = ["cache/cache_bench_tool.cc"],
+    auto_headers = AutoHeaders.RECURSIVE_GLOB,
+    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"],
+    external_deps = ROCKSDB_EXTERNAL_DEPS,
+    link_whole = False,
+)
+
 cpp_library(
    name = "rocksdb_stress_lib",
    srcs = [
@@ -800,9 +850,11 @@ cpp_library(
        "db_stress_tool/db_stress_common.cc",
        "db_stress_tool/db_stress_driver.cc",
        "db_stress_tool/db_stress_gflags.cc",
+        "db_stress_tool/db_stress_listener.cc",
        "db_stress_tool/db_stress_shared_state.cc",
        "db_stress_tool/db_stress_test_base.cc",
        "db_stress_tool/db_stress_tool.cc",
+        "db_stress_tool/expected_state.cc",
        "db_stress_tool/no_batched_ops_stress.cc",
        "test_util/testutil.cc",
        "tools/block_cache_analyzer/block_cache_trace_analyzer.cc",
@@ -884,6 +936,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "blob_counting_iterator_test",
+        "db/blob/blob_counting_iterator_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "blob_db_test",
        "utilities/blob_db/blob_db_test.cc",
@@ -926,6 +985,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "blob_garbage_meter_test",
+        "db/blob/blob_garbage_meter_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "block_based_filter_block_test",
        "table/block_based/block_based_filter_block_test.cc",
@@ -975,6 +1041,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "cache_reservation_manager_test",
+        "cache/cache_reservation_manager_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "cache_simulator_test",
        "utilities/simulator_cache/cache_simulator_test.cc",
@@ -1031,6 +1104,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "clipping_iterator_test",
+        "db/compaction/clipping_iterator_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "coding_test",
        "util/coding_test.cc",
@@ -1087,6 +1167,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "compaction_service_test",
+        "db/compaction/compaction_service_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "comparator_db_test",
        "db/comparator_db_test.cc",
@@ -1409,6 +1496,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "db_write_buffer_manager_test",
+        "db/db_write_buffer_manager_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "db_write_test",
        "db/db_write_test.cc",
@@ -113,5 +113,14 @@ 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/.
+
+## 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.

@@ -173,6 +173,11 @@ 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",
@@ -17,7 +17,7 @@ load(":defs.bzl", "test_binary")

 REPO_PATH = package_name() + "/"

-ROCKSDB_COMPILER_FLAGS = [
+ROCKSDB_COMPILER_FLAGS_0 = [
    "-fno-builtin-memcmp",
    # Needed to compile in fbcode
    "-Wno-expansion-to-defined",
@@ -35,7 +35,7 @@ ROCKSDB_EXTERNAL_DEPS = [
    ("zstd", None, "zstd"),
 ]

-ROCKSDB_OS_DEPS = [
+ROCKSDB_OS_DEPS_0 = [
    (
        "linux",
        ["third-party//numa:numa", "third-party//liburing:uring", "third-party//tbb:tbb"],
@@ -46,7 +46,7 @@ ROCKSDB_OS_DEPS = [
    ),
 ]

-ROCKSDB_OS_PREPROCESSOR_FLAGS = [
+ROCKSDB_OS_PREPROCESSOR_FLAGS_0 = [
    (
        "linux",
        [
@@ -114,18 +114,18 @@ 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 [])
+ROCKSDB_COMPILER_FLAGS = ROCKSDB_COMPILER_FLAGS_0 + (["-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 += ([(
+ROCKSDB_OS_PREPROCESSOR_FLAGS = ROCKSDB_OS_PREPROCESSOR_FLAGS_0 + ([(
    "linux",
    ["-DROCKSDB_JEMALLOC"],
 )] if sanitizer == "" else [])

-ROCKSDB_OS_DEPS += ([(
+ROCKSDB_OS_DEPS = ROCKSDB_OS_DEPS_0 + ([(
    "linux",
    ["third-party//jemalloc:headers"],
 )] if sanitizer == "" else [])
@@ -69,10 +69,6 @@ if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
      source "$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 "$PWD/build_tools/fbcode_config_platform009.sh"
    fi
@@ -175,7 +171,10 @@ case "$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 $PLATFORM_CXXFLAGS -x c++ - -luring -o /dev/null 2>/dev/null  <<EOF
              #include <liburing.h>
@@ -190,9 +189,6 @@ EOF
                COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_IOURING_PRESENT"
            fi
        fi
-        if test -z "$USE_FOLLY_DISTRIBUTED_MUTEX"; then
-          USE_FOLLY_DISTRIBUTED_MUTEX=1
-        fi
        # PORT_FILES=port/linux/linux_specific.cc
        ;;
    SunOS)
@@ -597,11 +593,21 @@ EOF
            PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS -faligned-new -DHAVE_ALIGNED_NEW"
        fi
    fi
+    if ! test $ROCKSDB_DISABLE_BENCHMARK; then
+        # Test whether google benchmark is available
+        $CXX $PLATFORM_CXXFLAGS -x c++ - -o /dev/null -lbenchmark 2>/dev/null  <<EOF
+          #include <benchmark/benchmark.h>
+          int main() {}
+EOF
+        if [ "$?" = 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 $PLATFORM_CXXFLAGS -x c++ - -o /dev/null -Wshorten-64-to-32 2>/dev/null  <<EOF
    int main() {}
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+#
+# Check for some simple mistakes that should prevent commit or push
+
+BAD=""
+
+git grep 'namespace rocksdb' -- '*.[ch]*'
+if [ "$?" != "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
+
+if [ "$BAD" ]; then
+  exit 1
+fi
@@ -18,3 +18,4 @@ KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/32b8a2407b634df3f8f948
 BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/08634589372fa5f237bfd374e8c644a8364e78c1/2.32/platform009/ba86d1f/
 VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/6ae525939ad02e5e676855082fbbc7828dbafeac/3.15.0/platform009/7f3b187
 LUA_BASE=/mnt/gvfs/third-party2/lua/162efd9561a3d21f6869f4814011e9cf1b3ff4dc/5.3.4/platform009/a6271c4
+BENCHMARK_BASE=/mnt/gvfs/third-party2/benchmark/bce8d9564eaf161700aa3a20b1051564acf555fb/1.5.5/platform009/7f3b187
@@ -167,6 +167,4 @@ VALGRIND_VER="$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
@@ -63,6 +63,13 @@ else
 fi
 CFLAGS+=" -DGFLAGS=gflags"

+BENCHMARK_INCLUDE=" -I $BENCHMARK_BASE/include/"
+if test -z $PIC_BUILD; then
+  BENCHMARK_LIBS=" $BENCHMARK_BASE/lib/libbenchmark.a"
+else
+  BENCHMARK_LIBS=" $BENCHMARK_BASE/lib/libbenchmark_pic.a"
+fi
+
 # location of jemalloc
 JEMALLOC_INCLUDE=" -I $JEMALLOC_BASE/include/"
 JEMALLOC_LIB=" $JEMALLOC_BASE/lib/libjemalloc.a"
@@ -102,8 +109,9 @@ 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 +128,7 @@ 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 +141,7 @@ 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 +157,18 @@ 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 +176,4 @@ 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
@@ -120,7 +122,7 @@ 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 "$uncommitted_code" ]
 then
@@ -128,8 +130,8 @@ then
  [ "$FORMAT_REMOTE" ] || FORMAT_REMOTE="$(git remote -v | grep 'facebook/rocksdb.git' | head -n 1 | cut -f 1)"
  # Fall back on 'origin' if that fails
  [ "$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/$(git remote show $FORMAT_REMOTE | sed -n '/HEAD branch/s/.*: //p')"
  # Get the common ancestor with that remote branch. Everything after that
  # common ancestor would be considered the contents of a pull request, so
  # should be relevant for formatting fixes.
@@ -20,26 +20,11 @@ STAT_FILE=${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
@@ -286,12 +271,10 @@ 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 +361,7 @@ 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
 }

@@ -106,16 +106,14 @@ NON_SHM="TMPD=/tmp/rocksdb_test_tmp"
 GCC_481="ROCKSDB_FBCODE_BUILD_WITH_481=1"
 ASAN="COMPILE_WITH_ASAN=1"
 CLANG="USE_CLANG=1"
-# in gcc-5 there are known problems with TSAN like https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71090.
-# using platform007 gives us gcc-8 or higher which has that bug fixed.
-TSAN="ROCKSDB_FBCODE_BUILD_WITH_PLATFORM007=1 COMPILE_WITH_TSAN=1"
+TSAN="COMPILE_WITH_TSAN=1"
 UBSAN="COMPILE_WITH_UBSAN=1"
 TSAN_CRASH='CRASH_TEST_EXT_ARGS="--compression_type=zstd --log2_keys_per_lock=22"'
 NON_TSAN_CRASH="CRASH_TEST_EXT_ARGS=--compression_type=zstd"
 DISABLE_JEMALLOC="DISABLE_JEMALLOC=1"
 HTTP_PROXY="https_proxy=http://fwdproxy.29.prn1:8080 http_proxy=http://fwdproxy.29.prn1:8080 ftp_proxy=http://fwdproxy.29.prn1:8080"
 SETUP_JAVA_ENV="export $HTTP_PROXY; export JAVA_HOME=/usr/local/jdk-8u60-64/; export PATH=\$JAVA_HOME/bin:\$PATH"
-PARSER="'parser':'python build_tools/error_filter.py $1'"
+PARSER="'parser':'/usr/bin/env python3 build_tools/error_filter.py $1'"

 CONTRUN_NAME="ROCKSDB_CONTRUN_NAME"
 SKIP_FORMAT_CHECKS="SKIP_FORMAT_BUCK_CHECKS=1"
@@ -381,23 +379,6 @@ LITE_BUILD_COMMANDS="[
    }
 ]"

-#
-# Report RocksDB lite binary size to scuba
-REPORT_LITE_BINARY_SIZE_COMMANDS="[
-    {
-        'name':'Rocksdb Lite Binary Size',
-        'oncall':'$ONCALL',
-        'executeLocal': 'true',
-        'steps': [
-            $CLEANUP_ENV,
-            {
-                'name':'Report RocksDB Lite binary size to scuba',
-                'shell':'cd $WORKING_DIR; tools/report_lite_binary_size.sh',
-                'user':'root',
-            },
-        ],
-]"
-
 #
 # RocksDB stress/crash test
 #
@@ -590,7 +571,7 @@ WRITE_STRESS_COMMANDS="[
            $CLEANUP_ENV,
            {
                'name':'Build and run RocksDB write stress tests',
-                'shell':'cd $WORKING_DIR; make write_stress && python tools/write_stress_runner.py --runtime_sec=3600 --db=/tmp/rocksdb_write_stress || $CONTRUN_NAME=write_stress $TASK_CREATION_TOOL',
+                'shell':'cd $WORKING_DIR; make write_stress && /usr/bin/env python3 tools/write_stress_runner.py --runtime_sec=3600 --db=/tmp/rocksdb_write_stress || $CONTRUN_NAME=write_stress $TASK_CREATION_TOOL',
                'user':'root',
                $PARSER
            }
@@ -613,7 +594,7 @@ ASAN_TEST_COMMANDS="[
            $CLEANUP_ENV,
            {
                'name':'Test RocksDB debug under ASAN',
-'shell':'cd $WORKING_DIR; set -o pipefail && ($SHM $ASAN $DEBUG $SKIP_FORMAT_CHECKS make $PARALLELISM asan_check || $CONTRUN_NAME=asan_check $TASK_CREATION_TOOL) |& /usr/facebook/ops/scripts/asan_symbolize.py -d',
+'shell':'cd $WORKING_DIR; set -o pipefail && $SHM $ASAN $DEBUG $SKIP_FORMAT_CHECKS make $PARALLELISM asan_check || $CONTRUN_NAME=asan_check $TASK_CREATION_TOOL',
                'user':'root',
                $PARSER
            }
@@ -1122,7 +1103,7 @@ NO_COMPRESSION_COMMANDS="[
 #
 run_regression()
 {
-  time -v bash -vx ./build_tools/regression_build_test.sh $(mktemp -d  $WORKSPACE/leveldb.XXXX) $(mktemp leveldb_test_stats.XXXX)
+  time bash -vx ./build_tools/regression_build_test.sh $(mktemp -d  $WORKING_DIR/rocksdb.XXXX) $(mktemp rocksdb_test_stats.XXXX)

  # ======= report size to ODS ========

@@ -1163,6 +1144,7 @@ REGRESSION_COMMANDS="[
    {
        'name':'Rocksdb regression commands',
        'oncall':'$ONCALL',
+        'executeLocal': 'true',
        'steps': [
            $CLEANUP_ENV,
            {
@@ -1197,6 +1179,40 @@ JAVA_BUILD_TEST_COMMANDS="[
    }
 ]"

+#
+# RocksDB fbcode stress/crash test
+#
+FBCODE_STRESS_CRASH_TEST_COMMANDS="[
+    {
+        'name':'Rocksdb Fbcode Stress and Crash Test',
+        'oncall':'$ONCALL',
+        'executeLocal': 'true',
+        'timeout': 86400,
+        'steps': [
+            {
+                'name':'Copy RocksDB code to fbcode repo',
+                'shell':'cd internal_repo_rocksdb/repo && git init -b main && git add * && git commit -a -m \"Make internal_repo_rocksdb/repo a git repo\" && cd ../.. && echo Y | python3 rocks/release_script/release_to_fbcode.py -u internal_repo_rocksdb/repo main || $CONTRUN_NAME=db_stress_fbcode $TASK_CREATION_TOOL',
+                'user':'root',
+                $PARSER
+            },
+            {
+                'name':'Build RocksDB fbcode stress tests',
+                'shell':'cd $WORKING_DIR; buck build @mode/dbg rocks/tools:rocks_db_stress || $CONTRUN_NAME=db_stress_fbcode $TASK_CREATION_TOOL',
+                'user':'root',
+                $PARSER
+            },
+            {
+                'name':'Run RocksDB whitebox crash tests',
+                'timeout': 86400,
+                'shell':'cd $WORKING_DIR; mkdir /dev/shm/rocksdb_fbcode_crash_test && TEST_TMPDIR=\$(mktemp -d --tmpdir=/dev/shm/rocksdb_fbcode_crash_test) python3 rocksdb/src/tools/db_crashtest.py --stress_cmd=buck-out/dbg/gen/rocks/tools/rocks_db_stress -secondary_cache_uri=\"$SECONDARY_CACHE_URI\" --env_uri=$ENV_URI $EXTRA_DB_STRESS_ARGS -logtostderr=false $TEST_TYPE || $CONTRUN_NAME=db_stress_fbcode $TASK_CREATION_TOOL',
+                'user':'root',
+                $PARSER
+            },
+        ],
+        $REPORT
+    }
+]"
+

 case $1 in
  unit)
@@ -1232,9 +1248,6 @@ case $1 in
  lite)
    echo $LITE_BUILD_COMMANDS
    ;;
-  report_lite_binary_size)
-    echo $REPORT_LITE_BINARY_SIZE_COMMANDS
-    ;;
  stress_crash)
    echo $STRESS_CRASH_TEST_COMMANDS
    ;;
@@ -1329,11 +1342,18 @@ case $1 in
    echo $REGRESSION_COMMANDS
    ;;
  run_regression)
+    set -e
    run_regression
+    set +e
    ;;
  java_build)
    echo $JAVA_BUILD_TEST_COMMANDS
    ;;
+  fbcode_stress_crash)
+    set -f
+    echo $FBCODE_STRESS_CRASH_TEST_COMMANDS
+    set +f
+    ;;
  *)
    echo "Invalid determinator command"
    exit 1
@@ -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 +1,572 @@
+//  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 <cstdio>
+#include <limits>
+#include <set>
+#include <sstream>
+
+#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 "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, "");
+
+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 > (1u << 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(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 =
+          [](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");
+  }
+};
+
+int cache_bench_tool(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;
+  }
+}  // namespace ROCKSDB_NAMESPACE
+}  // namespace ROCKSDB_NAMESPACE
+
+#endif  // GFLAGS
@@ -0,0 +1,68 @@
+//  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",
+    "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",
+    "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 +1,127 @@
+//  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 <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,
+  // 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) {
+    delete static_cast<T*>(value);
+  }
+};
+
+template <CacheEntryRole R>
+struct RegisteredNoopDeleter {
+  RegisteredNoopDeleter() { RegisterCacheDeleterRole(Delete, R); }
+
+  static void Delete(const Slice& /* key */, void* value) {
+    (void)value;
+    assert(value == nullptr);
+  }
+};
+
+}  // 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 +1,181 @@
+//  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 "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) {
+    std::array<uint64_t, 3> cache_key_data{
+        {// First 16 bytes == md5 of class name
+         0x7eba5a8fb5437c90U, 0x8ca68c9b11655855U,
+         // Last 8 bytes based on a function pointer to make unique for each
+         // template instantiation
+         reinterpret_cast<uint64_t>(&CacheEntryStatsCollector::GetShared)}};
+    Slice cache_key = GetSlice(&cache_key_data);
+
+    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);
+  }
+
+  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 +1,131 @@
+//  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/block_based_table_reader.h"
+#include "util/coding.h"
+
+namespace ROCKSDB_NAMESPACE {
+CacheReservationManager::CacheReservationManager(std::shared_ptr<Cache> cache,
+                                                 bool delayed_decrease)
+    : delayed_decrease_(delayed_decrease), cache_allocated_size_(0) {
+  assert(cache != nullptr);
+  cache_ = cache;
+  std::memset(cache_key_, 0, kCacheKeyPrefixSize + kMaxVarint64Length);
+  EncodeVarint64(cache_key_, cache_->NewId());
+}
+
+CacheReservationManager::~CacheReservationManager() {
+  for (auto* handle : dummy_handles_) {
+    cache_->Release(handle, true);
+  }
+}
+
+template <CacheEntryRole R>
+Status CacheReservationManager::UpdateCacheReservation(
+    std::size_t 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<R>(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;
+    }
+  }
+}
+
+// Explicitly instantiate templates for "CacheEntryRole" values we use.
+// This makes it possible to keep the template definitions in the .cc file.
+template Status CacheReservationManager::UpdateCacheReservation<
+    CacheEntryRole::kWriteBuffer>(std::size_t new_mem_used);
+template Status CacheReservationManager::UpdateCacheReservation<
+    CacheEntryRole::kCompressionDictionaryBuildingBuffer>(
+    std::size_t new_mem_used);
+// For cache reservation manager unit tests
+template Status CacheReservationManager::UpdateCacheReservation<
+    CacheEntryRole::kMisc>(std::size_t new_mem_used);
+
+template <CacheEntryRole R>
+Status CacheReservationManager::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;
+}
+
+Status CacheReservationManager::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;
+}
+
+std::size_t CacheReservationManager::GetTotalReservedCacheSize() {
+  return cache_allocated_size_.load(std::memory_order_relaxed);
+}
+
+Slice CacheReservationManager::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.
+  std::memset(cache_key_ + kCacheKeyPrefixSize, 0, kMaxVarint64Length);
+  char* end =
+      EncodeVarint64(cache_key_ + kCacheKeyPrefixSize, next_cache_key_id_++);
+  return Slice(cache_key_, static_cast<std::size_t>(end - cache_key_));
+}
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,98 @@
+//  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 <vector>
+
+#include "cache/cache_entry_roles.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/status.h"
+#include "table/block_based/block_based_table_reader.h"
+#include "util/coding.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// CacheReservationManager is for reserving cache space for the memory used
+// through inserting/releasing dummy entries in the cache.
+// This class is not thread-safe.
+class CacheReservationManager {
+ public:
+  // Construct a CacheReservationManager
+  // @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.
+  explicit CacheReservationManager(std::shared_ptr<Cache> cache,
+                                   bool delayed_decrease = false);
+
+  // no copy constructor, copy assignment, move constructor, move assignment
+  CacheReservationManager(const CacheReservationManager &) = delete;
+  CacheReservationManager &operator=(const CacheReservationManager &) = delete;
+  CacheReservationManager(CacheReservationManager &&) = delete;
+  CacheReservationManager &operator=(CacheReservationManager &&) = delete;
+
+  ~CacheReservationManager();
+
+  template <CacheEntryRole R>
+
+  // Insert and release dummy entries in the cache to
+  // match the size of total dummy entries with the smallest multiple of
+  // kSizeDummyEntry that is 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
+  // @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);
+  std::size_t GetTotalReservedCacheSize();
+
+ private:
+  static constexpr std::size_t kSizeDummyEntry = 256 * 1024;
+  // The key will be longer than keys for blocks in SST files so they won't
+  // conflict.
+  static const std::size_t kCacheKeyPrefixSize =
+      BlockBasedTable::kMaxCacheKeyPrefixSize + kMaxVarint64Length;
+
+  Slice GetNextCacheKey();
+  template <CacheEntryRole R>
+  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::vector<Cache::Handle *> dummy_handles_;
+  std::uint64_t next_cache_key_id_ = 0;
+  // The non-prefix part will be updated according to the ID to use.
+  char cache_key_[kCacheKeyPrefixSize + kMaxVarint64Length];
+};
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,411 @@
+//  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 "table/block_based/block_based_table_reader.h"
+#include "test_util/testharness.h"
+#include "util/coding.h"
+
+namespace ROCKSDB_NAMESPACE {
+class CacheReservationManagerTest : public ::testing::Test {
+ protected:
+  static constexpr std::size_t kOneGigabyte = 1024 * 1024 * 1024;
+  static constexpr int kNumShardBits = 0;  // 2^0 shard
+
+  static constexpr std::size_t kSizeDummyEntry = 256 * 1024;
+  static const std::size_t kCacheKeyPrefixSize =
+      BlockBasedTable::kMaxCacheKeyPrefixSize + kMaxVarint64Length;
+  static constexpr std::size_t kMetaDataChargeOverhead = 10000;
+
+  std::shared_ptr<Cache> cache = NewLRUCache(kOneGigabyte, kNumShardBits);
+  std::unique_ptr<CacheReservationManager> test_cache_rev_mng;
+
+  CacheReservationManagerTest() {
+    test_cache_rev_mng.reset(new CacheReservationManager(cache));
+  }
+};
+
+TEST_F(CacheReservationManagerTest, GenerateCacheKey) {
+  // The first cache reservation manager owning the cache will have
+  // cache->NewId() = 1
+  constexpr std::size_t kCacheNewId = 1;
+  // The first key generated inside of cache reservation manager will have
+  // next_cache_key_id = 0
+  constexpr std::size_t kCacheKeyId = 0;
+
+  char expected_cache_key[kCacheKeyPrefixSize + kMaxVarint64Length];
+  std::memset(expected_cache_key, 0, kCacheKeyPrefixSize + kMaxVarint64Length);
+
+  EncodeVarint64(expected_cache_key, kCacheNewId);
+  char* end =
+      EncodeVarint64(expected_cache_key + kCacheKeyPrefixSize, kCacheKeyId);
+  Slice expected_cache_key_slice(
+      expected_cache_key, static_cast<std::size_t>(end - expected_cache_key));
+
+  std::size_t new_mem_used = 1 * kSizeDummyEntry;
+  Status s =
+      test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry);
+  ASSERT_LT(cache->GetPinnedUsage(),
+            1 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  Cache::Handle* handle = cache->Lookup(expected_cache_key_slice);
+  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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            1 * kSizeDummyEntry);
+  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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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(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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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 kOneMegabyte = 1024 * 1024;
+  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 = kOneMegabyte;
+  lo.num_shard_bits = 0;  // 2^0 shard
+  lo.strict_capacity_limit = true;
+  std::shared_ptr<Cache> cache = NewLRUCache(lo);
+  std::unique_ptr<CacheReservationManager> test_cache_rev_mng(
+      new CacheReservationManager(cache));
+
+  std::size_t new_mem_used = kOneMegabyte + 1;
+  Status s =
+      test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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(), kOneMegabyte)
+      << "Failed to bookkeep correctly (i.e, bookkeep only successful dummy "
+         "entry insertions) when encountering cache resevation failure due to "
+         "full cache";
+  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(), kOneMegabyte)
+      << "Failed to insert underlying dummy entries correctly when "
+         "encountering cache resevation failure due to full cache";
+
+  new_mem_used = kOneMegabyte / 2;  // 2 dummy entries
+  s = test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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 = kOneMegabyte + 1;
+  s = test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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(), kOneMegabyte)
+      << "Failed to bookkeep correctly (i.e, bookkeep only successful dummy "
+         "entry insertions) when encountering cache resevation failure due to "
+         "full cache";
+  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(), kOneMegabyte)
+      << "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(kOneGigabyte);
+  new_mem_used = kOneMegabyte + 1;
+  s = test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            2 * kSizeDummyEntry);
+  ASSERT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry);
+  ASSERT_LT(cache->GetPinnedUsage(),
+            2 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  new_mem_used = 1 * kSizeDummyEntry;
+  s = test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            2 * kSizeDummyEntry);
+  ASSERT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry);
+  ASSERT_LT(cache->GetPinnedUsage(),
+            2 * kSizeDummyEntry + kMetaDataChargeOverhead);
+
+  new_mem_used = kSizeDummyEntry / 2;
+  s = test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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 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::unique_ptr<CacheReservationManager> test_cache_rev_mng(
+      new CacheReservationManager(cache, true /* delayed_decrease */));
+
+  std::size_t new_mem_used = 8 * kSizeDummyEntry;
+  Status s =
+      test_cache_rev_mng
+          ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              new_mem_used);
+  ASSERT_EQ(s, Status::OK());
+  ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
+            8 * kSizeDummyEntry);
+  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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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(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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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(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<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+              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_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 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::unique_ptr<CacheReservationManager> test_cache_rev_mng(
+        new CacheReservationManager(cache));
+    std::size_t new_mem_used = 1 * kSizeDummyEntry;
+    Status s =
+        test_cache_rev_mng
+            ->UpdateCacheReservation<ROCKSDB_NAMESPACE::CacheEntryRole::kMisc>(
+                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";
+}
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -712,25 +712,98 @@ 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 +822,12 @@ 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);
 }

@@ -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);
@@ -218,13 +220,11 @@ 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.
@@ -260,7 +260,7 @@ 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<CacheKey, CacheHandle*, CacheKey>;

  ClockCacheShard();
  ~ClockCacheShard() override;
@@ -271,7 +271,26 @@ 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 force_erase) override {
+    return Release(handle, force_erase);
+  }
+  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.
  //
@@ -284,8 +303,10 @@ class ClockCacheShard final : public CacheShard {
  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 +425,46 @@ 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 +473,8 @@ 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 +502,7 @@ 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 +516,11 @@ 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 +528,6 @@ 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)) {
@@ -567,8 +614,9 @@ 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);
@@ -594,8 +642,18 @@ 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))) {
@@ -726,11 +784,11 @@ 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 +804,17 @@ 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 {
+#ifndef MUST_FREE_HEAP_ALLOCATIONS
+    shards_ = nullptr;
+#endif
+  }
+
+  void WaitAll(std::vector<Handle*>& /*handles*/) override {}

 private:
  ClockCacheShard* shards_;
@@ -10,24 +10,29 @@
 #include "cache/lru_cache.h"

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

+#include "monitoring/perf_context_imp.h"
+#include "monitoring/statistics.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 +46,7 @@ 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 +66,7 @@ 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 +74,29 @@ 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;
@@ -89,23 +104,25 @@ 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
  lru_.next = &lru_;
@@ -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) {
@@ -256,8 +294,14 @@ void LRUCacheShard::SetCapacity(size_t capacity) {
    EvictFromLRU(0, &last_reference_list);
  }

+  // 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();
  }
 }
@@ -267,17 +311,181 @@ 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);
+Status LRUCacheShard::InsertItem(LRUHandle* e, Cache::Handle** handle,
+                                 bool free_handle_on_fail) {
+  Status s = Status::OK();
+  autovector<LRUHandle*> last_reference_list;
+  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
+    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.
+        last_reference_list.push_back(e);
+      } else {
+        if (free_handle_on_fail) {
+          delete[] reinterpret_cast<char*>(e);
+          *handle = nullptr;
+        }
+        s = Status::Incomplete("Insert failed due to LRU cache being full.");
+      }
+    } else {
+      // Insert into the cache. Note that the cache might get larger than its
+      // capacity if not enough space was freed up.
+      LRUHandle* old = table_.Insert(e);
+      usage_ += total_charge;
+      if (old != nullptr) {
+        s = Status::OkOverwritten();
+        assert(old->InCache());
+        old->SetInCache(false);
+        if (!old->HasRefs()) {
+          // 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_);
+          assert(usage_ >= old_total_charge);
+          usage_ -= old_total_charge;
+          last_reference_list.push_back(old);
+        }
+      }
+      if (handle == nullptr) {
+        LRU_Insert(e);
+      } else {
+        // If caller already holds a ref, no need to take one here
+        if (!e->HasRefs()) {
+          e->Ref();
+        }
+        *handle = reinterpret_cast<Cache::Handle*>(e);
+      }
+    }
+  }
+
+  // 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);
+      }
    }
-    e->Ref();
-    e->SetHit();
  }
  return reinterpret_cast<Cache::Handle*>(e);
 }
@@ -321,7 +529,12 @@ bool LRUCacheShard::Release(Cache::Handle* handle, bool force_erase) {
        last_reference = false;
      }
    }
-    if (last_reference) {
+    // 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;
@@ -338,81 +551,35 @@ bool LRUCacheShard::Release(Cache::Handle* handle, bool force_erase) {
 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()]);
-  Status s = Status::OK();
-  autovector<LRUHandle*> last_reference_list;

  e->value = value;
-  e->deleter = deleter;
+  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->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
-    EvictFromLRU(total_charge, &last_reference_list);
-
-    if ((usage_ + total_charge) > capacity_ &&
-        (strict_capacity_limit_ || handle == nullptr)) {
-      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;
-        s = Status::Incomplete("Insert failed due to LRU cache being full.");
-      }
-    } else {
-      // Insert into the cache. Note that the cache might get larger than its
-      // capacity if not enough space was freed up.
-      LRUHandle* old = table_.Insert(e);
-      usage_ += total_charge;
-      if (old != nullptr) {
-        s = Status::OkOverwritten();
-        assert(old->InCache());
-        old->SetInCache(false);
-        if (!old->HasRefs()) {
-          // 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_);
-          assert(usage_ >= old_total_charge);
-          usage_ -= old_total_charge;
-          last_reference_list.push_back(old);
-        }
-      }
-      if (handle == nullptr) {
-        LRU_Insert(e);
-      } else {
-        e->Ref();
-        *handle = reinterpret_cast<Cache::Handle*>(e);
-      }
-    }
-  }
-
-  // Free the entries here outside of mutex for performance reasons
-  for (auto entry : last_reference_list) {
-    entry->Free();
-  }
-
-  return s;
+  return InsertItem(e, handle, /* free_handle_on_fail */ true);
 }

 void LRUCacheShard::Erase(const Slice& key, uint32_t hash) {
@@ -442,6 +609,18 @@ void LRUCacheShard::Erase(const Slice& key, uint32_t hash) {
  }
 }

+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)
+#ifndef MUST_FREE_HEAP_ALLOCATIONS
  shards_ = nullptr;
  num_shards_ = 0;
 #endif
-#else  // __clang__
-#ifndef __SANITIZE_ADDRESS__
-  shards_ = nullptr;
-  num_shards_ = 0;
-#endif  // !__SANITIZE_ADDRESS__
-#endif  // __clang__
 }

 size_t LRUCache::TEST_GetLRUSize() {
@@ -543,19 +727,42 @@ 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
  }
@@ -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) {
@@ -122,10 +157,53 @@ 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);
  }
@@ -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.
@@ -193,7 +284,9 @@ 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
@@ -209,11 +302,35 @@ 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 force_erase) override {
+    return Release(handle, force_erase);
+  }
+  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;
@@ -226,8 +343,10 @@ 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;

@@ -243,6 +362,23 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {
  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.
+  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);

@@ -303,6 +439,8 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard final : public CacheShard {
  // 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
@@ -316,15 +454,18 @@ 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
  size_t TEST_GetLRUSize();
@@ -334,6 +475,7 @@ class LRUCache
 private:
  LRUCacheShard* shards_ = nullptr;
  int num_shards_ = 0;
+  std::shared_ptr<SecondaryCache> secondary_cache_;
 };

 }  // namespace ROCKSDB_NAMESPACE
@@ -9,53 +9,96 @@

 #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);
@@ -66,6 +109,11 @@ bool ShardedCache::Release(Handle* handle, bool force_erase) {
  return GetShard(Shard(hash))->Release(handle, force_erase);
 }

+bool ShardedCache::Release(Handle* handle, bool useful, bool force_erase) {
+  uint32_t hash = GetHash(handle);
+  return GetShard(Shard(hash))->Release(handle, useful, force_erase);
+}
+
 void ShardedCache::Erase(const Slice& key) {
  uint32_t hash = HashSlice(key);
  GetShard(Shard(hash))->Erase(key, hash);
@@ -87,9 +135,9 @@ 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 +149,42 @@ 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 +199,8 @@ 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 +225,8 @@ 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 force_erase) = 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 force_erase) = 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(
@@ -57,22 +74,29 @@ 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 force_erase = 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 void Erase(const Slice& key) 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_;
@@ -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 |
@@ -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;
@@ -88,16 +87,15 @@ Status ArenaWrappedDBIter::Refresh() {
 }

 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 +1,22 @@
+//  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,
+                              PinnableSlice* blob_value) {
+  Status s;
+  assert(version_);
+  constexpr uint64_t* bytes_read = nullptr;
+  s = version_->GetBlob(read_options_, user_key, blob_index, blob_value,
+                        bytes_read);
+  return s;
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,26 @@
+//  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 BlobFetcher {
+ public:
+  BlobFetcher(Version* version, const ReadOptions& read_options)
+      : version_(version), read_options_(read_options) {}
+
+  Status FetchBlob(const Slice& user_key, const Slice& blob_index,
+                   PinnableSlice* blob_value);
+
+ private:
+  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,
-      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");
  }

@@ -295,22 +314,25 @@ 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;
  blob_bytes_ = 0;
@@ -331,15 +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"

@@ -16,14 +17,48 @@ namespace ROCKSDB_NAMESPACE {

 class BlobFileCompletionCallback {
 public:
-  BlobFileCompletionCallback(SstFileManager* sst_file_manager,
-                             InstrumentedMutex* mutex,
-                             ErrorHandler* error_handler)
-      : sst_file_manager_(sst_file_manager),
-        mutex_(mutex),
-        error_handler_(error_handler) {}
+  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
+    (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
@@ -39,15 +74,28 @@ class BlobFileCompletionCallback {
        error_handler_->SetBGError(s, BackgroundErrorReason::kFlush);
      }
    }
-#else
-    (void)file_name;
-#endif  // ROCKSDB_LITE
+#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();
@@ -10,6 +10,7 @@

 #include "db/blob/blob_log_format.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 +18,14 @@
 #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 +35,7 @@ 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 +44,47 @@ 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 +117,22 @@ 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,
-      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 +147,9 @@ Status BlobFileReader::ReadHeader(const RandomAccessFileReader* file_reader,
    constexpr uint64_t read_offset = 0;
    constexpr size_t read_size = BlobLogHeader::kSize;

-    const Status s = ReadFromFile(file_reader, read_offset, read_size,
-                                  &header_slice, &buf, &aligned_buf);
+    const Status s =
+        ReadFromFile(file_reader, read_offset, read_size, statistics,
+                     &header_slice, &buf, &aligned_buf);
    if (!s.ok()) {
      return s;
    }
@@ -176,8 +182,8 @@ 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 +197,9 @@ Status BlobFileReader::ReadFooter(uint64_t file_size,
    const uint64_t read_offset = file_size - BlobLogFooter::kSize;
    constexpr size_t read_size = BlobLogFooter::kSize;

-    const Status s = ReadFromFile(file_reader, read_offset, read_size,
-                                  &footer_slice, &buf, &aligned_buf);
+    const Status s =
+        ReadFromFile(file_reader, read_offset, read_size, statistics,
+                     &footer_slice, &buf, &aligned_buf);
    if (!s.ok()) {
      return s;
    }
@@ -221,14 +228,16 @@ 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) {
  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()) {
@@ -257,10 +266,13 @@ 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_);
 }

@@ -305,7 +317,7 @@ Status BlobFileReader::GetBlob(const ReadOptions& read_options,
    TEST_SYNC_POINT("BlobFileReader::GetBlob:ReadFromFile");

    const Status s = ReadFromFile(file_reader_.get(), record_offset,
-                                  static_cast<size_t>(record_size),
+                                  static_cast<size_t>(record_size), statistics_,
                                  &record_slice, &buf, &aligned_buf);
    if (!s.ok()) {
      return s;
@@ -325,8 +337,8 @@ 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 +351,124 @@ 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);
+  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 +513,8 @@ 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 +532,14 @@ 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 +11,22 @@
 #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 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,
@@ -42,11 +44,24 @@ class BlobFileReader {
                 CompressionType compression_type, 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,
@@ -55,17 +70,17 @@ 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,
+                             Statistics* statistics, Slice* slice, Buffer* buf,
                             AlignedBuf* aligned_buf);

  static Status VerifyBlob(const Slice& record_slice, const Slice& user_key,
@@ -73,6 +88,8 @@ class BlobFileReader {

  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 +97,8 @@ class BlobFileReader {
  std::unique_ptr<RandomAccessFileReader> file_reader_;
  uint64_t file_size_;
  CompressionType compression_type_;
+  SystemClock* clock_;
+  Statistics* statistics_;
 };

 }  // namespace ROCKSDB_NAMESPACE
@@ -27,124 +27,153 @@ 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;
@@ -154,10 +183,36 @@ 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_EQ(bytes_read, blob_size);
+    ASSERT_OK(reader->GetBlob(read_options, keys[0], blob_offsets[0],
+                              blob_sizes[0], kNoCompression, &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 +221,15 @@ 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, &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 +238,9 @@ 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, &value,
+                              &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -194,8 +251,9 @@ 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, &value,
+                              &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -206,8 +264,8 @@ 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, &value, &bytes_read)
                    .IsCorruption());
    ASSERT_EQ(bytes_read, 0);
  }
@@ -220,23 +278,82 @@ 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, &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, &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 +362,35 @@ 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, &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 +399,13 @@ 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 +414,23 @@ 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 +443,7 @@ 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 +452,12 @@ 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 +469,15 @@ 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 +486,14 @@ 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 +507,7 @@ 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 +516,7 @@ 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 +525,14 @@ 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 +546,7 @@ 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 +555,7 @@ 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 +564,14 @@ 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 +583,9 @@ 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 +593,7 @@ 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 +602,13 @@ 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 +620,17 @@ 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) {
@@ -517,12 +661,13 @@ 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 +679,8 @@ 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;
@@ -543,8 +688,8 @@ 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;
@@ -583,14 +728,14 @@ 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 +747,8 @@ 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 +756,8 @@ 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) {
@@ -642,13 +787,13 @@ 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 +809,14 @@ 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 +828,13 @@ 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 +843,8 @@ 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");
@@ -727,10 +872,11 @@ 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 +888,14 @@ 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 +907,9 @@ 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 +926,8 @@ 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";
@@ -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;
  }

@@ -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;

@@ -267,6 +577,247 @@ TEST_F(DBBlobBasicTest, GenerateIOTracing) {
 }
 #endif  // !ROCKSDB_LITE

+TEST_F(DBBlobBasicTest, BestEffortsRecovery_MissingNewestBlobFile) {
+  Options options = GetDefaultOptions();
+  options.enable_blob_files = true;
+  options.min_blob_size = 0;
+  options.create_if_missing = true;
+  Reopen(options);
+
+  ASSERT_OK(dbfull()->DisableFileDeletions());
+  constexpr int kNumTableFiles = 2;
+  for (int i = 0; i < kNumTableFiles; ++i) {
+    for (char ch = 'a'; ch != 'c'; ++ch) {
+      std::string key(1, ch);
+      ASSERT_OK(Put(key, "value" + std::to_string(i)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  Close();
+
+  std::vector<std::string> files;
+  ASSERT_OK(env_->GetChildren(dbname_, &files));
+  std::string blob_file_path;
+  uint64_t max_blob_file_num = kInvalidBlobFileNumber;
+  for (const auto& fname : files) {
+    uint64_t file_num = 0;
+    FileType type;
+    if (ParseFileName(fname, &file_num, /*info_log_name_prefix=*/"", &type) &&
+        type == kBlobFile) {
+      if (file_num > max_blob_file_num) {
+        max_blob_file_num = file_num;
+        blob_file_path = dbname_ + "/" + fname;
+      }
+    }
+  }
+  ASSERT_OK(env_->DeleteFile(blob_file_path));
+
+  options.best_efforts_recovery = true;
+  Reopen(options);
+  std::string value;
+  ASSERT_OK(db_->Get(ReadOptions(), "a", &value));
+  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[] = "0000000000";
+  constexpr size_t blob_size = sizeof(blob) - 1;
+
+  ASSERT_OK(Put(key1, blob));
+  ASSERT_OK(Put(key2, blob));
+  ASSERT_OK(Flush());
+
+  constexpr size_t first_blob_file_expected_size =
+      BlobLogHeader::kSize +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(key1_size) + blob_size +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(key2_size) + 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) + blob_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
+      << '\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:
@@ -279,11 +830,21 @@ 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();
@@ -313,7 +874,7 @@ 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;
@@ -355,6 +916,53 @@ 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 {
@@ -410,8 +1018,17 @@ TEST_P(DBBlobBasicIOErrorTest, CompactionFilterReadBlob_IOError) {

 }  // namespace ROCKSDB_NAMESPACE

+#ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+extern "C" {
+void RegisterCustomObjects(int argc, char** argv);
+}
+#else
+void RegisterCustomObjects(int /*argc*/, char** /*argv*/) {}
+#endif  // !ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+
 int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
  return RUN_ALL_TESTS();
 }
@@ -4,17 +4,17 @@
 //  (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() {
@@ -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 +458,151 @@ 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()->TEST_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);
+
+  {
+    auto it = blob_files.begin();
+    const auto& meta = it->second;
+    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);
+  }
+
+  {
+    auto it = blob_files.rbegin();
+    const auto& meta = it->second;
+    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();
+}
+
 }  // namespace ROCKSDB_NAMESPACE

+#ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+extern "C" {
+void RegisterCustomObjects(int argc, char** argv);
+}
+#else
+void RegisterCustomObjects(int /*argc*/, char** /*argv*/) {}
+#endif  // !ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+
 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
@@ -74,8 +74,17 @@ TEST_F(DBBlobCorruptionTest, VerifyWholeBlobFileChecksum) {
 #endif  // !ROCKSDB_LITE
 }  // namespace ROCKSDB_NAMESPACE

+#ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+extern "C" {
+void RegisterCustomObjects(int argc, char** argv);
+}
+#else
+void RegisterCustomObjects(int /*argc*/, char** /*argv*/) {}
+#endif  // !ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+
 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 +462,119 @@ 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

+#ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+extern "C" {
+void RegisterCustomObjects(int argc, char** argv);
+}
+#else
+void RegisterCustomObjects(int /*argc*/, char** /*argv*/) {}
+#endif  // !ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+
 int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
  return RUN_ALL_TESTS();
 }
@@ -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.file_checksum_gen_factory,
-          tmp_set.Contains(FileType::kTableFile)));
+          ioptions.stats, ioptions.listeners,
+          ioptions.file_checksum_gen_factory.get(),
+          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, 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");
@@ -280,7 +311,7 @@ Status BuildTable(
      if (s.ok()) {
        s = blob_file_builder->Finish();
      } else {
-        blob_file_builder->Abandon();
+        blob_file_builder->Abandon(s);
      }
      blob_file_builder.reset();
    }
@@ -296,20 +327,20 @@ 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,
+          read_options, file_options, tboptions.internal_comparator, *meta,
          nullptr /* range_del_agg */,
          mutable_cf_options.prefix_extractor.get(), 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()) {
@@ -354,9 +385,9 @@ Status BuildTable(
  }
  // 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, s, 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
@@ -40,6 +40,7 @@
 #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"
@@ -79,11 +80,15 @@ using ROCKSDB_NAMESPACE::IngestExternalFileOptions;
 using ROCKSDB_NAMESPACE::Iterator;
 using ROCKSDB_NAMESPACE::LiveFileMetaData;
 using ROCKSDB_NAMESPACE::Logger;
+using ROCKSDB_NAMESPACE::LRUCacheOptions;
+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;
@@ -102,6 +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;
@@ -150,6 +156,12 @@ struct rocksdb_filelock_t        { FileLock*         rep; };
 struct rocksdb_logger_t {
  std::shared_ptr<Logger> rep;
 };
+struct rocksdb_lru_cache_options_t {
+  LRUCacheOptions rep;
+};
+struct rocksdb_memory_allocator_t {
+  std::shared_ptr<MemoryAllocator> rep;
+};
 struct rocksdb_cache_t {
  std::shared_ptr<Cache> rep;
 };
@@ -1501,6 +1513,10 @@ 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) {
@@ -2682,6 +2698,68 @@ unsigned char rocksdb_options_get_skip_checking_sst_file_sizes_on_db_open(
  return opt->rep.skip_checking_sst_file_sizes_on_db_open;
 }

+/* Blob Options Settings */
+void rocksdb_options_set_enable_blob_files(rocksdb_options_t* opt,
+                                           unsigned char val) {
+  opt->rep.enable_blob_files = val;
+}
+extern ROCKSDB_LIBRARY_API unsigned char rocksdb_options_get_enable_blob_files(
+    rocksdb_options_t* opt) {
+  return opt->rep.enable_blob_files;
+}
+
+void rocksdb_options_set_min_blob_size(rocksdb_options_t* opt, uint64_t val) {
+  opt->rep.min_blob_size = val;
+}
+
+uint64_t rocksdb_options_get_min_blob_size(rocksdb_options_t* opt) {
+  return opt->rep.min_blob_size;
+}
+
+void rocksdb_options_set_blob_file_size(rocksdb_options_t* opt, uint64_t val) {
+  opt->rep.blob_file_size = val;
+}
+
+uint64_t rocksdb_options_get_blob_file_size(rocksdb_options_t* opt) {
+  return opt->rep.blob_file_size;
+}
+
+void rocksdb_options_set_blob_compression_type(rocksdb_options_t* opt,
+                                               int val) {
+  opt->rep.blob_compression_type = static_cast<CompressionType>(val);
+}
+
+int rocksdb_options_get_blob_compression_type(rocksdb_options_t* opt) {
+  return opt->rep.blob_compression_type;
+}
+
+void rocksdb_options_set_enable_blob_gc(rocksdb_options_t* opt,
+                                        unsigned char val) {
+  opt->rep.enable_blob_garbage_collection = val;
+}
+
+unsigned char rocksdb_options_get_enable_blob_gc(rocksdb_options_t* opt) {
+  return opt->rep.enable_blob_garbage_collection;
+}
+
+void rocksdb_options_set_blob_gc_age_cutoff(rocksdb_options_t* opt,
+                                            double val) {
+  opt->rep.blob_garbage_collection_age_cutoff = val;
+}
+
+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_num_levels(rocksdb_options_t* opt, int n) {
  opt->rep.num_levels = n;
 }
@@ -2796,11 +2874,31 @@ 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);
@@ -2940,6 +3038,11 @@ 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) {
@@ -3415,6 +3518,15 @@ 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;
+}
+
 rocksdb_ratelimiter_t* rocksdb_ratelimiter_create(
    int64_t rate_bytes_per_sec,
    int64_t refill_period_us,
@@ -3436,6 +3548,14 @@ 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);
@@ -3729,7 +3849,8 @@ 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.
@@ -3764,14 +3885,63 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_format(int bits_per_ke
  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(); }
+    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);
+    }
+    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->delete_filter_ = 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,
@@ -4102,16 +4272,58 @@ unsigned char rocksdb_flushoptions_get_wait(rocksdb_flushoptions_t* opt) {
  return opt->rep.wait;
 }

+rocksdb_memory_allocator_t* rocksdb_jemalloc_nodump_allocator_create(
+    char** errptr) {
+  rocksdb_memory_allocator_t* allocator = new rocksdb_memory_allocator_t;
+  ROCKSDB_NAMESPACE::JemallocAllocatorOptions options;
+  SaveError(errptr, ROCKSDB_NAMESPACE::NewJemallocNodumpAllocator(
+                        options, &allocator->rep));
+  return allocator;
+}
+
+void rocksdb_memory_allocator_destroy(rocksdb_memory_allocator_t* allocator) {
+  delete allocator;
+}
+
+rocksdb_lru_cache_options_t* rocksdb_lru_cache_options_create() {
+  return new rocksdb_lru_cache_options_t;
+}
+
+void rocksdb_lru_cache_options_destroy(rocksdb_lru_cache_options_t* opt) {
+  delete opt;
+}
+
+void rocksdb_lru_cache_options_set_capacity(rocksdb_lru_cache_options_t* opt,
+                                            size_t capacity) {
+  opt->rep.capacity = capacity;
+}
+
+void rocksdb_lru_cache_options_set_memory_allocator(
+    rocksdb_lru_cache_options_t* opt, rocksdb_memory_allocator_t* allocator) {
+  opt->rep.memory_allocator = allocator->rep;
+}
+
 rocksdb_cache_t* rocksdb_cache_create_lru(size_t capacity) {
  rocksdb_cache_t* c = new rocksdb_cache_t;
  c->rep = NewLRUCache(capacity);
  return c;
 }

+rocksdb_cache_t* rocksdb_cache_create_lru_opts(
+    rocksdb_lru_cache_options_t* opt) {
+  rocksdb_cache_t* c = new rocksdb_cache_t;
+  c->rep = NewLRUCache(opt->rep);
+  return c;
+}
+
 void rocksdb_cache_destroy(rocksdb_cache_t* cache) {
  delete cache;
 }

+void rocksdb_cache_disown_data(rocksdb_cache_t* cache) {
+  cache->rep->DisownData();
+}
+
 void rocksdb_cache_set_capacity(rocksdb_cache_t* cache, size_t capacity) {
  cache->rep->SetCapacity(capacity);
 }
@@ -4681,6 +4893,27 @@ 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,
@@ -4751,6 +4984,27 @@ 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,
@@ -5153,12 +5407,31 @@ 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(
@@ -517,6 +517,9 @@ 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);
@@ -1040,19 +1043,25 @@ 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 = 0; run <= 4; run++) {
+    // run=0 uses custom filter
+    // 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);
+      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);

@@ -1118,9 +1127,12 @@ int main(int argc, char** argv) {
      } else if (run == 1) {
        // Essentially a fingerprint of the block-based Bloom schema
        CheckCondition(hits == 241);
-      } else {
+      } else if (run == 2 || run == 4) {
        // 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 +1288,9 @@ 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 };
@@ -1759,6 +1774,31 @@ 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));
+
+    /* Blob Options */
+    rocksdb_options_set_enable_blob_files(o, 1);
+    CheckCondition(1 == rocksdb_options_get_enable_blob_files(o));
+
+    rocksdb_options_set_min_blob_size(o, 29);
+    CheckCondition(29 == rocksdb_options_get_min_blob_size(o));
+
+    rocksdb_options_set_blob_file_size(o, 30);
+    CheckCondition(30 == rocksdb_options_get_blob_file_size(o));
+
+    rocksdb_options_set_blob_compression_type(o, 4);
+    CheckCondition(4 == rocksdb_options_get_blob_compression_type(o));
+
+    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, 0.5);
+    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));
+
    // Create a copy that should be equal to the original.
    rocksdb_options_t* copy;
    copy = rocksdb_options_create_copy(o);
@@ -2362,6 +2402,37 @@ int main(int argc, char** argv) {
    rocksdb_cache_destroy(co);
  }

+  StartPhase("jemalloc_nodump_allocator");
+  {
+    rocksdb_memory_allocator_t* allocator;
+    allocator = rocksdb_jemalloc_nodump_allocator_create(&err);
+    if (err != NULL) {
+      // not supported on all platforms, allow unsupported error
+      const char* ni = "Not implemented: ";
+      size_t ni_len = strlen(ni);
+      size_t err_len = strlen(err);
+
+      CheckCondition(err_len >= ni_len);
+      CheckCondition(memcmp(ni, err, ni_len) == 0);
+      Free(&err);
+    } else {
+      rocksdb_cache_t* co;
+      rocksdb_lru_cache_options_t* copts;
+
+      copts = rocksdb_lru_cache_options_create();
+
+      rocksdb_lru_cache_options_set_capacity(copts, 100);
+      rocksdb_lru_cache_options_set_memory_allocator(copts, allocator);
+
+      co = rocksdb_cache_create_lru_opts(copts);
+      CheckCondition(100 == rocksdb_cache_get_capacity(co));
+
+      rocksdb_cache_destroy(co);
+      rocksdb_lru_cache_options_destroy(copts);
+    }
+    rocksdb_memory_allocator_destroy(allocator);
+  }
+
  StartPhase("env");
  {
    rocksdb_env_t* e;
@@ -2480,6 +2551,28 @@ int main(int argc, char** argv) {
    rocksdb_backupable_db_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");
  {
    // Create new empty database
@@ -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"
@@ -109,8 +109,9 @@ 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 +203,7 @@ 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) {
@@ -214,7 +215,8 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
  // 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 +285,7 @@ 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 +294,7 @@ 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 +311,7 @@ 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 +349,18 @@ 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 +451,9 @@ 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 +463,7 @@ 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 +481,10 @@ 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 +511,10 @@ 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 +557,7 @@ 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 +572,8 @@ 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 +591,13 @@ 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 +606,12 @@ 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 +667,14 @@ 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 +684,17 @@ 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 +901,7 @@ 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 +914,7 @@ 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 +923,7 @@ 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 +935,7 @@ 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 +957,7 @@ 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 +982,7 @@ 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 +996,7 @@ 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 +1010,7 @@ 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 +1055,10 @@ 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();
 }
@@ -1203,11 +1215,11 @@ 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 +1263,13 @@ 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 +1358,25 @@ 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 &&
+      db_options.max_open_files != -1 && cf_options.ttl > 0) {
+    return Status::NotSupported(
+        "FIFO compaction only supported with max_open_files = -1.");
  }

  return s;
@@ -1411,7 +1435,8 @@ 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;
      }
@@ -1442,21 +1467,23 @@ 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_;
@@ -1522,7 +1549,8 @@ 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);
@@ -208,8 +208,6 @@ struct SuperVersion {
  uint64_t version_number;
  WriteStallCondition write_stall_condition;

-  InstrumentedMutex* db_mutex;
-
  // should be called outside the mutex
  SuperVersion() = default;
  ~SuperVersion();
@@ -258,8 +256,7 @@ extern ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
 // one too.
 extern void GetIntTblPropCollectorFactory(
    const ImmutableCFOptions& ioptions,
-    std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-        int_tbl_prop_collector_factories);
+    IntTblPropCollectorFactories* int_tbl_prop_collector_factories);

 class ColumnFamilySet;

@@ -282,8 +279,7 @@ class ColumnFamilyData {
  // UnrefAndTryDelete() decreases the reference count and do free if needed,
  // return true if this is freed else false, UnrefAndTryDelete() can only
  // be called while holding a DB mutex, or during single-threaded recovery.
-  // sv_under_cleanup is only provided when called from SuperVersion::Cleanup.
-  bool UnrefAndTryDelete(SuperVersion* sv_under_cleanup = nullptr);
+  bool UnrefAndTryDelete();

  // SetDropped() can only be called under following conditions:
  // 1) Holding a DB mutex,
@@ -316,7 +312,7 @@ class ColumnFamilyData {
  FlushReason GetFlushReason() const { return flush_reason_; }
  // thread-safe
  const FileOptions* soptions() const;
-  const ImmutableCFOptions* ioptions() const { return &ioptions_; }
+  const ImmutableOptions* ioptions() const { return &ioptions_; }
  // REQUIRES: DB mutex held
  // This returns the MutableCFOptions used by current SuperVersion
  // You should use this API to reference MutableCFOptions most of the time.
@@ -361,6 +357,7 @@ class ColumnFamilyData {
  uint64_t GetNumLiveVersions() const;  // REQUIRE: DB mutex held
  uint64_t GetTotalSstFilesSize() const;  // REQUIRE: DB mutex held
  uint64_t GetLiveSstFilesSize() const;   // REQUIRE: DB mutex held
+  uint64_t GetTotalBlobFileSize() const;  // REQUIRE: DB mutex held
  void SetMemtable(MemTable* new_mem) {
    uint64_t memtable_id = last_memtable_id_.fetch_add(1) + 1;
    new_mem->SetID(memtable_id);
@@ -428,8 +425,7 @@ class ColumnFamilyData {
    return internal_comparator_;
  }

-  const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
-  int_tbl_prop_collector_factories() const {
+  const IntTblPropCollectorFactories* int_tbl_prop_collector_factories() const {
    return &int_tbl_prop_collector_factories_;
  }

@@ -455,7 +451,6 @@ class ColumnFamilyData {
  // the clients to allocate SuperVersion outside of mutex.
  // IMPORTANT: Only call this from DBImpl::InstallSuperVersion()
  void InstallSuperVersion(SuperVersionContext* sv_context,
-                           InstrumentedMutex* db_mutex,
                           const MutableCFOptions& mutable_cf_options);
  void InstallSuperVersion(SuperVersionContext* sv_context,
                           InstrumentedMutex* db_mutex);
@@ -522,6 +517,7 @@ class ColumnFamilyData {
  }

  ThreadLocalPtr* TEST_GetLocalSV() { return local_sv_.get(); }
+  WriteBufferManager* write_buffer_mgr() { return write_buffer_manager_; }

 private:
  friend class ColumnFamilySet;
@@ -531,10 +527,11 @@ class ColumnFamilyData {
                   WriteBufferManager* write_buffer_manager,
                   const ColumnFamilyOptions& options,
                   const ImmutableDBOptions& db_options,
-                   const FileOptions& file_options,
+                   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);

  std::vector<std::string> GetDbPaths() const;

@@ -548,11 +545,10 @@ class ColumnFamilyData {
  std::atomic<bool> dropped_;  // true if client dropped it

  const InternalKeyComparator internal_comparator_;
-  std::vector<std::unique_ptr<IntTblPropCollectorFactory>>
-      int_tbl_prop_collector_factories_;
+  IntTblPropCollectorFactories int_tbl_prop_collector_factories_;

  const ColumnFamilyOptions initial_cf_options_;
-  const ImmutableCFOptions ioptions_;
+  const ImmutableOptions ioptions_;
  MutableCFOptions mutable_cf_options_;

  const bool is_delete_range_supported_;
@@ -671,7 +667,8 @@ class ColumnFamilySet {
                  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);
  ~ColumnFamilySet();

  ColumnFamilyData* GetDefault() const;
@@ -721,6 +718,8 @@ class ColumnFamilySet {
  std::unordered_map<uint32_t, ColumnFamilyData*> column_family_data_;

  uint32_t max_column_family_;
+  const FileOptions file_options_;
+
  ColumnFamilyData* dummy_cfd_;
  // We don't hold the refcount here, since default column family always exists
  // We are also not responsible for cleaning up default_cfd_cache_. This is
@@ -730,12 +729,12 @@ class ColumnFamilySet {

  const std::string db_name_;
  const ImmutableDBOptions* const db_options_;
-  const FileOptions file_options_;
  Cache* table_cache_;
  WriteBufferManager* write_buffer_manager_;
  WriteController* write_controller_;
  BlockCacheTracer* const block_cache_tracer_;
  std::shared_ptr<IOTracer> io_tracer_;
+  std::string db_session_id_;
 };

 // We use ColumnFamilyMemTablesImpl to provide WriteBatch a way to access
@@ -56,16 +56,8 @@ class ColumnFamilyTestBase : public testing::Test {
 public:
  explicit ColumnFamilyTestBase(uint32_t format) : rnd_(139), format_(format) {
    Env* base_env = Env::Default();
-#ifndef ROCKSDB_LITE
-    const char* test_env_uri = getenv("TEST_ENV_URI");
-    if (test_env_uri) {
-      Env* test_env = nullptr;
-      Status s = Env::LoadEnv(test_env_uri, &test_env, &env_guard_);
-      base_env = test_env;
-      EXPECT_OK(s);
-      EXPECT_NE(Env::Default(), base_env);
-    }
-#endif  // !ROCKSDB_LITE
+    EXPECT_OK(
+        test::CreateEnvFromSystem(ConfigOptions(), &base_env, &env_guard_));
    EXPECT_NE(nullptr, base_env);
    env_ = new EnvCounter(base_env);
    env_->skip_fsync_ = true;
@@ -2286,6 +2278,8 @@ TEST_P(ColumnFamilyTest, SanitizeOptions) {
              // not a multiple of 4k, round up 4k
              expected_arena_block_size += 4 * 1024;
            }
+            expected_arena_block_size =
+                std::min(size_t{1024 * 1024}, expected_arena_block_size);
            ASSERT_EQ(expected_arena_block_size, result.arena_block_size);
          }
        }
@@ -2981,7 +2975,8 @@ TEST_P(ColumnFamilyTest, FlushCloseWALFiles) {
  SpecialEnv env(Env::Default());
  db_options_.env = &env;
  db_options_.max_background_flushes = 1;
-  column_family_options_.memtable_factory.reset(new SpecialSkipListFactory(2));
+  column_family_options_.memtable_factory.reset(
+      test::NewSpecialSkipListFactory(2));
  Open();
  CreateColumnFamilies({"one"});
  ASSERT_OK(Put(1, "fodor", "mirko"));
@@ -3026,7 +3021,8 @@ TEST_P(ColumnFamilyTest, IteratorCloseWALFile1) {
  SpecialEnv env(Env::Default());
  db_options_.env = &env;
  db_options_.max_background_flushes = 1;
-  column_family_options_.memtable_factory.reset(new SpecialSkipListFactory(2));
+  column_family_options_.memtable_factory.reset(
+      test::NewSpecialSkipListFactory(2));
  Open();
  CreateColumnFamilies({"one"});
  ASSERT_OK(Put(1, "fodor", "mirko"));
@@ -3077,7 +3073,8 @@ TEST_P(ColumnFamilyTest, IteratorCloseWALFile2) {
  env.SetBackgroundThreads(2, Env::HIGH);
  db_options_.env = &env;
  db_options_.max_background_flushes = 1;
-  column_family_options_.memtable_factory.reset(new SpecialSkipListFactory(2));
+  column_family_options_.memtable_factory.reset(
+      test::NewSpecialSkipListFactory(2));
  Open();
  CreateColumnFamilies({"one"});
  ASSERT_OK(Put(1, "fodor", "mirko"));
@@ -3135,7 +3132,8 @@ TEST_P(ColumnFamilyTest, ForwardIteratorCloseWALFile) {
  env.SetBackgroundThreads(2, Env::HIGH);
  db_options_.env = &env;
  db_options_.max_background_flushes = 1;
-  column_family_options_.memtable_factory.reset(new SpecialSkipListFactory(3));
+  column_family_options_.memtable_factory.reset(
+      test::NewSpecialSkipListFactory(3));
  column_family_options_.level0_file_num_compaction_trigger = 2;
  Open();
  CreateColumnFamilies({"one"});
@@ -3409,6 +3407,30 @@ TEST(ColumnFamilyTest, ValidateBlobGCCutoff) {
                  .IsInvalidArgument());
 }

+TEST(ColumnFamilyTest, ValidateBlobGCForceThreshold) {
+  DBOptions db_options;
+
+  ColumnFamilyOptions cf_options;
+  cf_options.enable_blob_garbage_collection = true;
+
+  cf_options.blob_garbage_collection_force_threshold = -0.5;
+  ASSERT_TRUE(ColumnFamilyData::ValidateOptions(db_options, cf_options)
+                  .IsInvalidArgument());
+
+  cf_options.blob_garbage_collection_force_threshold = 0.0;
+  ASSERT_OK(ColumnFamilyData::ValidateOptions(db_options, cf_options));
+
+  cf_options.blob_garbage_collection_force_threshold = 0.5;
+  ASSERT_OK(ColumnFamilyData::ValidateOptions(db_options, cf_options));
+
+  cf_options.blob_garbage_collection_force_threshold = 1.0;
+  ASSERT_OK(ColumnFamilyData::ValidateOptions(db_options, cf_options));
+
+  cf_options.blob_garbage_collection_force_threshold = 1.5;
+  ASSERT_TRUE(ColumnFamilyData::ValidateOptions(db_options, cf_options)
+                  .IsInvalidArgument());
+}
+
 }  // namespace ROCKSDB_NAMESPACE

 #ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
@@ -0,0 +1,275 @@
+//  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 "table/internal_iterator.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// An internal iterator that wraps another one and ensures that any keys
+// returned are strictly within a range [start, end). If the underlying
+// iterator has already performed the bounds checking, it relies on that result;
+// otherwise, it performs the necessary key comparisons itself. Both bounds
+// are optional.
+class ClippingIterator : public InternalIterator {
+ public:
+  ClippingIterator(InternalIterator* iter, const Slice* start, const Slice* end,
+                   const Comparator* cmp)
+      : iter_(iter), start_(start), end_(end), cmp_(cmp), valid_(false) {
+    assert(iter_);
+    assert(cmp_);
+    assert(!start_ || !end_ || cmp_->Compare(*start_, *end_) <= 0);
+
+    UpdateAndEnforceBounds();
+  }
+
+  bool Valid() const override { return valid_; }
+
+  void SeekToFirst() override {
+    if (start_) {
+      iter_->Seek(*start_);
+    } else {
+      iter_->SeekToFirst();
+    }
+
+    UpdateAndEnforceUpperBound();
+  }
+
+  void SeekToLast() override {
+    if (end_) {
+      iter_->SeekForPrev(*end_);
+
+      // Upper bound is exclusive, so we need a key which is strictly smaller
+      if (iter_->Valid() && cmp_->Compare(iter_->key(), *end_) == 0) {
+        iter_->Prev();
+      }
+    } else {
+      iter_->SeekToLast();
+    }
+
+    UpdateAndEnforceLowerBound();
+  }
+
+  void Seek(const Slice& target) override {
+    if (start_ && cmp_->Compare(target, *start_) < 0) {
+      iter_->Seek(*start_);
+      UpdateAndEnforceUpperBound();
+      return;
+    }
+
+    if (end_ && cmp_->Compare(target, *end_) >= 0) {
+      valid_ = false;
+      return;
+    }
+
+    iter_->Seek(target);
+    UpdateAndEnforceUpperBound();
+  }
+
+  void SeekForPrev(const Slice& target) override {
+    if (start_ && cmp_->Compare(target, *start_) < 0) {
+      valid_ = false;
+      return;
+    }
+
+    if (end_ && cmp_->Compare(target, *end_) >= 0) {
+      iter_->SeekForPrev(*end_);
+
+      // Upper bound is exclusive, so we need a key which is strictly smaller
+      if (iter_->Valid() && cmp_->Compare(iter_->key(), *end_) == 0) {
+        iter_->Prev();
+      }
+
+      UpdateAndEnforceLowerBound();
+      return;
+    }
+
+    iter_->SeekForPrev(target);
+    UpdateAndEnforceLowerBound();
+  }
+
+  void Next() override {
+    assert(valid_);
+    iter_->Next();
+    UpdateAndEnforceUpperBound();
+  }
+
+  bool NextAndGetResult(IterateResult* result) override {
+    assert(valid_);
+    assert(result);
+
+    IterateResult res;
+    valid_ = iter_->NextAndGetResult(&res);
+
+    if (!valid_) {
+      return false;
+    }
+
+    if (end_) {
+      EnforceUpperBoundImpl(res.bound_check_result);
+
+      if (!valid_) {
+        return false;
+      }
+    }
+
+    res.bound_check_result = IterBoundCheck::kInbound;
+    *result = res;
+
+    return true;
+  }
+
+  void Prev() override {
+    assert(valid_);
+    iter_->Prev();
+    UpdateAndEnforceLowerBound();
+  }
+
+  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 iter_->status(); }
+
+  bool PrepareValue() override {
+    assert(valid_);
+
+    if (iter_->PrepareValue()) {
+      return true;
+    }
+
+    assert(!iter_->Valid());
+    valid_ = false;
+    return false;
+  }
+
+  bool MayBeOutOfLowerBound() override {
+    assert(valid_);
+    return false;
+  }
+
+  IterBoundCheck UpperBoundCheckResult() override {
+    assert(valid_);
+    return IterBoundCheck::kInbound;
+  }
+
+  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 UpdateValid() {
+    assert(!iter_->Valid() || iter_->status().ok());
+
+    valid_ = iter_->Valid();
+  }
+
+  void EnforceUpperBoundImpl(IterBoundCheck bound_check_result) {
+    if (bound_check_result == IterBoundCheck::kInbound) {
+      return;
+    }
+
+    if (bound_check_result == IterBoundCheck::kOutOfBound) {
+      valid_ = false;
+      return;
+    }
+
+    assert(bound_check_result == IterBoundCheck::kUnknown);
+
+    if (cmp_->Compare(key(), *end_) >= 0) {
+      valid_ = false;
+    }
+  }
+
+  void EnforceUpperBound() {
+    if (!valid_) {
+      return;
+    }
+
+    if (!end_) {
+      return;
+    }
+
+    EnforceUpperBoundImpl(iter_->UpperBoundCheckResult());
+  }
+
+  void EnforceLowerBound() {
+    if (!valid_) {
+      return;
+    }
+
+    if (!start_) {
+      return;
+    }
+
+    if (!iter_->MayBeOutOfLowerBound()) {
+      return;
+    }
+
+    if (cmp_->Compare(key(), *start_) < 0) {
+      valid_ = false;
+    }
+  }
+
+  void AssertBounds() {
+    assert(!valid_ || !start_ || cmp_->Compare(key(), *start_) >= 0);
+    assert(!valid_ || !end_ || cmp_->Compare(key(), *end_) < 0);
+  }
+
+  void UpdateAndEnforceBounds() {
+    UpdateValid();
+    EnforceUpperBound();
+    EnforceLowerBound();
+    AssertBounds();
+  }
+
+  void UpdateAndEnforceUpperBound() {
+    UpdateValid();
+    EnforceUpperBound();
+    AssertBounds();
+  }
+
+  void UpdateAndEnforceLowerBound() {
+    UpdateValid();
+    EnforceLowerBound();
+    AssertBounds();
+  }
+
+  InternalIterator* iter_;
+  const Slice* start_;
+  const Slice* end_;
+  const Comparator* cmp_;
+  bool valid_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,258 @@
+//  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/compaction/clipping_iterator.h"
+
+#include <algorithm>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "db/dbformat.h"
+#include "rocksdb/comparator.h"
+#include "test_util/testharness.h"
+#include "test_util/testutil.h"
+#include "util/vector_iterator.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// A vector iterator which does its own bounds checking. This is for testing the
+// optimizations in the clipping iterator where we bypass the bounds checking if
+// the input iterator has already performed it.
+class BoundsCheckingVectorIterator : public VectorIterator {
+ public:
+  BoundsCheckingVectorIterator(const std::vector<std::string>& keys,
+                               const std::vector<std::string>& values,
+                               const Slice* start, const Slice* end,
+                               const Comparator* cmp)
+      : VectorIterator(keys, values, cmp), start_(start), end_(end), cmp_(cmp) {
+    assert(cmp_);
+  }
+
+  bool NextAndGetResult(IterateResult* result) override {
+    assert(Valid());
+    assert(result);
+
+    Next();
+
+    if (!Valid()) {
+      return false;
+    }
+
+    result->key = key();
+    result->bound_check_result = UpperBoundCheckResult();
+    result->value_prepared = true;
+
+    return true;
+  }
+
+  bool MayBeOutOfLowerBound() override {
+    assert(Valid());
+
+    if (!start_) {
+      return false;
+    }
+
+    return cmp_->Compare(key(), *start_) < 0;
+  }
+
+  IterBoundCheck UpperBoundCheckResult() override {
+    assert(Valid());
+
+    if (!end_) {
+      return IterBoundCheck::kInbound;
+    }
+
+    return cmp_->Compare(key(), *end_) >= 0 ? IterBoundCheck::kOutOfBound
+                                            : IterBoundCheck::kInbound;
+  }
+
+ private:
+  const Slice* start_;
+  const Slice* end_;
+  const Comparator* cmp_;
+};
+
+class ClippingIteratorTest
+    : public ::testing::Test,
+      public ::testing::WithParamInterface<std::tuple<bool, size_t, size_t>> {};
+
+TEST_P(ClippingIteratorTest, Clip) {
+  const std::vector<std::string> keys{"key0", "key1", "key2", "key3", "key4",
+                                      "key5", "key6", "key7", "key8", "key9"};
+  const std::vector<std::string> values{
+      "unused0", "value1",  "value2",  "value3",  "unused4",
+      "unused5", "unused6", "unused7", "unused8", "unused9"};
+
+  assert(keys.size() == values.size());
+
+  // Note: the input always contains key1, key2, and key3; however, the clipping
+  // window is based on the test parameters: its left edge is a value in the
+  // range [0, 4], and its size is a value in the range [0, 5]
+  const std::vector<std::string> input_keys{keys[1], keys[2], keys[3]};
+  const std::vector<std::string> input_values{values[1], values[2], values[3]};
+
+  const bool use_bounds_checking_vec_it = std::get<0>(GetParam());
+
+  const size_t clip_start_idx = std::get<1>(GetParam());
+  const size_t clip_window_size = std::get<2>(GetParam());
+  const size_t clip_end_idx = clip_start_idx + clip_window_size;
+
+  const Slice start(keys[clip_start_idx]);
+  const Slice end(keys[clip_end_idx]);
+
+  std::unique_ptr<InternalIterator> input(
+      use_bounds_checking_vec_it
+          ? new BoundsCheckingVectorIterator(input_keys, input_values, &start,
+                                             &end, BytewiseComparator())
+          : new VectorIterator(input_keys, input_values, BytewiseComparator()));
+
+  ClippingIterator clip(input.get(), &start, &end, BytewiseComparator());
+
+  // The range the clipping iterator should return values from. This is
+  // essentially the intersection of the input range [1, 4) and the clipping
+  // window [clip_start_idx, clip_end_idx)
+  const size_t data_start_idx =
+      std::max(clip_start_idx, static_cast<size_t>(1));
+  const size_t data_end_idx = std::min(clip_end_idx, static_cast<size_t>(4));
+
+  // Range is empty; all Seeks should fail
+  if (data_start_idx >= data_end_idx) {
+    clip.SeekToFirst();
+    ASSERT_FALSE(clip.Valid());
+
+    clip.SeekToLast();
+    ASSERT_FALSE(clip.Valid());
+
+    for (size_t i = 0; i < keys.size(); ++i) {
+      clip.Seek(keys[i]);
+      ASSERT_FALSE(clip.Valid());
+
+      clip.SeekForPrev(keys[i]);
+      ASSERT_FALSE(clip.Valid());
+    }
+
+    return;
+  }
+
+  // Range is non-empty; call SeekToFirst and iterate forward
+  clip.SeekToFirst();
+  ASSERT_TRUE(clip.Valid());
+  ASSERT_EQ(clip.key(), keys[data_start_idx]);
+  ASSERT_EQ(clip.value(), values[data_start_idx]);
+  ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+  ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+
+  for (size_t i = data_start_idx + 1; i < data_end_idx; ++i) {
+    clip.Next();
+    ASSERT_TRUE(clip.Valid());
+    ASSERT_EQ(clip.key(), keys[i]);
+    ASSERT_EQ(clip.value(), values[i]);
+    ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+    ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+  }
+
+  clip.Next();
+  ASSERT_FALSE(clip.Valid());
+
+  // Do it again using NextAndGetResult
+  clip.SeekToFirst();
+  ASSERT_TRUE(clip.Valid());
+  ASSERT_EQ(clip.key(), keys[data_start_idx]);
+  ASSERT_EQ(clip.value(), values[data_start_idx]);
+  ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+  ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+
+  for (size_t i = data_start_idx + 1; i < data_end_idx; ++i) {
+    IterateResult result;
+    ASSERT_TRUE(clip.NextAndGetResult(&result));
+    ASSERT_EQ(result.key, keys[i]);
+    ASSERT_EQ(result.bound_check_result, IterBoundCheck::kInbound);
+    ASSERT_TRUE(clip.Valid());
+    ASSERT_EQ(clip.key(), keys[i]);
+    ASSERT_EQ(clip.value(), values[i]);
+    ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+    ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+  }
+
+  IterateResult result;
+  ASSERT_FALSE(clip.NextAndGetResult(&result));
+  ASSERT_FALSE(clip.Valid());
+
+  // Call SeekToLast and iterate backward
+  clip.SeekToLast();
+  ASSERT_TRUE(clip.Valid());
+  ASSERT_EQ(clip.key(), keys[data_end_idx - 1]);
+  ASSERT_EQ(clip.value(), values[data_end_idx - 1]);
+  ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+  ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+
+  for (size_t i = data_end_idx - 2; i >= data_start_idx; --i) {
+    clip.Prev();
+    ASSERT_TRUE(clip.Valid());
+    ASSERT_EQ(clip.key(), keys[i]);
+    ASSERT_EQ(clip.value(), values[i]);
+    ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+    ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+  }
+
+  clip.Prev();
+  ASSERT_FALSE(clip.Valid());
+
+  // Call Seek/SeekForPrev for all keys; Seek should return the smallest key
+  // which is >= the target; SeekForPrev should return the largest key which is
+  // <= the target
+  for (size_t i = 0; i < keys.size(); ++i) {
+    clip.Seek(keys[i]);
+
+    if (i < data_start_idx) {
+      ASSERT_TRUE(clip.Valid());
+      ASSERT_EQ(clip.key(), keys[data_start_idx]);
+      ASSERT_EQ(clip.value(), values[data_start_idx]);
+      ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+      ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+    } else if (i < data_end_idx) {
+      ASSERT_TRUE(clip.Valid());
+      ASSERT_EQ(clip.key(), keys[i]);
+      ASSERT_EQ(clip.value(), values[i]);
+      ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+      ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+    } else {
+      ASSERT_FALSE(clip.Valid());
+    }
+
+    clip.SeekForPrev(keys[i]);
+
+    if (i < data_start_idx) {
+      ASSERT_FALSE(clip.Valid());
+    } else if (i < data_end_idx) {
+      ASSERT_TRUE(clip.Valid());
+      ASSERT_EQ(clip.key(), keys[i]);
+      ASSERT_EQ(clip.value(), values[i]);
+      ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+      ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+    } else {
+      ASSERT_TRUE(clip.Valid());
+      ASSERT_EQ(clip.key(), keys[data_end_idx - 1]);
+      ASSERT_EQ(clip.value(), values[data_end_idx - 1]);
+      ASSERT_FALSE(clip.MayBeOutOfLowerBound());
+      ASSERT_EQ(clip.UpperBoundCheckResult(), IterBoundCheck::kInbound);
+    }
+  }
+}
+
+INSTANTIATE_TEST_CASE_P(
+    ClippingIteratorTest, ClippingIteratorTest,
+    ::testing::Combine(
+        ::testing::Bool(),
+        ::testing::Range(static_cast<size_t>(0), static_cast<size_t>(5)),
+        ::testing::Range(static_cast<size_t>(0), static_cast<size_t>(6))));
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -204,27 +204,24 @@ bool Compaction::IsFullCompaction(
  return num_files_in_compaction == total_num_files;
 }

-Compaction::Compaction(VersionStorageInfo* vstorage,
-                       const ImmutableCFOptions& _immutable_cf_options,
-                       const MutableCFOptions& _mutable_cf_options,
-                       const MutableDBOptions& _mutable_db_options,
-                       std::vector<CompactionInputFiles> _inputs,
-                       int _output_level, uint64_t _target_file_size,
-                       uint64_t _max_compaction_bytes, uint32_t _output_path_id,
-                       CompressionType _compression,
-                       CompressionOptions _compression_opts,
-                       uint32_t _max_subcompactions,
-                       std::vector<FileMetaData*> _grandparents,
-                       bool _manual_compaction, double _score,
-                       bool _deletion_compaction,
-                       CompactionReason _compaction_reason)
+Compaction::Compaction(
+    VersionStorageInfo* vstorage, const ImmutableOptions& _immutable_options,
+    const MutableCFOptions& _mutable_cf_options,
+    const MutableDBOptions& _mutable_db_options,
+    std::vector<CompactionInputFiles> _inputs, int _output_level,
+    uint64_t _target_file_size, uint64_t _max_compaction_bytes,
+    uint32_t _output_path_id, CompressionType _compression,
+    CompressionOptions _compression_opts, Temperature _output_temperature,
+    uint32_t _max_subcompactions, std::vector<FileMetaData*> _grandparents,
+    bool _manual_compaction, double _score, bool _deletion_compaction,
+    CompactionReason _compaction_reason)
    : input_vstorage_(vstorage),
      start_level_(_inputs[0].level),
      output_level_(_output_level),
      max_output_file_size_(_target_file_size),
      max_compaction_bytes_(_max_compaction_bytes),
      max_subcompactions_(_max_subcompactions),
-      immutable_cf_options_(_immutable_cf_options),
+      immutable_options_(_immutable_options),
      mutable_cf_options_(_mutable_cf_options),
      input_version_(nullptr),
      number_levels_(vstorage->num_levels()),
@@ -232,6 +229,7 @@ Compaction::Compaction(VersionStorageInfo* vstorage,
      output_path_id_(_output_path_id),
      output_compression_(_compression),
      output_compression_opts_(_compression_opts),
+      output_temperature_(_output_temperature),
      deletion_compaction_(_deletion_compaction),
      inputs_(PopulateWithAtomicBoundaries(vstorage, std::move(_inputs))),
      grandparents_(std::move(_grandparents)),
@@ -240,7 +238,8 @@ Compaction::Compaction(VersionStorageInfo* vstorage,
      is_full_compaction_(IsFullCompaction(vstorage, inputs_)),
      is_manual_compaction_(_manual_compaction),
      is_trivial_move_(false),
-      compaction_reason_(_compaction_reason) {
+      compaction_reason_(_compaction_reason),
+      notify_on_compaction_completion_(false) {
  MarkFilesBeingCompacted(true);
  if (is_manual_compaction_) {
    compaction_reason_ = CompactionReason::kManualCompaction;
@@ -278,7 +277,7 @@ Compaction::~Compaction() {

 bool Compaction::InputCompressionMatchesOutput() const {
  int base_level = input_vstorage_->base_level();
-  bool matches = (GetCompressionType(immutable_cf_options_, input_vstorage_,
+  bool matches = (GetCompressionType(immutable_options_, input_vstorage_,
                                     mutable_cf_options_, start_level_,
                                     base_level) == output_compression_);
  if (matches) {
@@ -303,13 +302,19 @@ bool Compaction::IsTrivialMove() const {
  }

  if (is_manual_compaction_ &&
-      (immutable_cf_options_.compaction_filter != nullptr ||
-       immutable_cf_options_.compaction_filter_factory != nullptr)) {
+      (immutable_options_.compaction_filter != nullptr ||
+       immutable_options_.compaction_filter_factory != nullptr)) {
    // This is a manual compaction and we have a compaction filter that should
    // be executed, we cannot do a trivial move
    return false;
  }

+  if (start_level_ == output_level_) {
+    // It doesn't make sense if compaction picker picks files just to trivial
+    // move to the same level.
+    return false;
+  }
+
  // Used in universal compaction, where trivial move can be done if the
  // input files are non overlapping
  if ((mutable_cf_options_.compaction_options_universal.allow_trivial_move) &&
@@ -512,7 +517,7 @@ uint64_t Compaction::OutputFilePreallocationSize() const {
  }

  if (max_output_file_size_ != port::kMaxUint64 &&
-      (immutable_cf_options_.compaction_style == kCompactionStyleLevel ||
+      (immutable_options_.compaction_style == kCompactionStyleLevel ||
       output_level() > 0)) {
    preallocation_size = std::min(max_output_file_size_, preallocation_size);
  }
@@ -529,16 +534,23 @@ std::unique_ptr<CompactionFilter> Compaction::CreateCompactionFilter() const {
    return nullptr;
  }

+  if (!cfd_->ioptions()
+           ->compaction_filter_factory->ShouldFilterTableFileCreation(
+               TableFileCreationReason::kCompaction)) {
+    return nullptr;
+  }
+
  CompactionFilter::Context context;
  context.is_full_compaction = is_full_compaction_;
  context.is_manual_compaction = is_manual_compaction_;
  context.column_family_id = cfd_->GetID();
+  context.reason = TableFileCreationReason::kCompaction;
  return cfd_->ioptions()->compaction_filter_factory->CreateCompactionFilter(
      context);
 }

 std::unique_ptr<SstPartitioner> Compaction::CreateSstPartitioner() const {
-  if (!immutable_cf_options_.sst_partitioner_factory) {
+  if (!immutable_options_.sst_partitioner_factory) {
    return nullptr;
  }

@@ -548,8 +560,7 @@ std::unique_ptr<SstPartitioner> Compaction::CreateSstPartitioner() const {
  context.output_level = output_level_;
  context.smallest_user_key = smallest_user_key_;
  context.largest_user_key = largest_user_key_;
-  return immutable_cf_options_.sst_partitioner_factory->CreatePartitioner(
-      context);
+  return immutable_options_.sst_partitioner_factory->CreatePartitioner(context);
 }

 bool Compaction::IsOutputLevelEmpty() const {
@@ -560,6 +571,14 @@ bool Compaction::ShouldFormSubcompactions() const {
  if (max_subcompactions_ <= 1 || cfd_ == nullptr) {
    return false;
  }
+
+  // Note: the subcompaction boundary picking logic does not currently guarantee
+  // that all user keys that differ only by timestamp get processed by the same
+  // subcompaction.
+  if (cfd_->user_comparator()->timestamp_size() > 0) {
+    return false;
+  }
+
  if (cfd_->ioptions()->compaction_style == kCompactionStyleLevel) {
    return (start_level_ == 0 || is_manual_compaction_) && output_level_ > 0 &&
           !IsOutputLevelEmpty();
@@ -570,6 +589,29 @@ bool Compaction::ShouldFormSubcompactions() const {
  }
 }

+bool Compaction::DoesInputReferenceBlobFiles() const {
+  assert(input_version_);
+
+  const VersionStorageInfo* storage_info = input_version_->storage_info();
+  assert(storage_info);
+
+  if (storage_info->GetBlobFiles().empty()) {
+    return false;
+  }
+
+  for (size_t i = 0; i < inputs_.size(); ++i) {
+    for (const FileMetaData* meta : inputs_[i].files) {
+      assert(meta);
+
+      if (meta->oldest_blob_file_number != kInvalidBlobFileNumber) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
 uint64_t Compaction::MinInputFileOldestAncesterTime() const {
  uint64_t min_oldest_ancester_time = port::kMaxUint64;
  for (const auto& level_files : inputs_) {
@@ -70,13 +70,14 @@ class CompactionFilter;
 class Compaction {
 public:
  Compaction(VersionStorageInfo* input_version,
-             const ImmutableCFOptions& immutable_cf_options,
+             const ImmutableOptions& immutable_options,
             const MutableCFOptions& mutable_cf_options,
             const MutableDBOptions& mutable_db_options,
             std::vector<CompactionInputFiles> inputs, int output_level,
             uint64_t target_file_size, uint64_t max_compaction_bytes,
             uint32_t output_path_id, CompressionType compression,
-             CompressionOptions compression_opts, uint32_t max_subcompactions,
+             CompressionOptions compression_opts,
+             Temperature output_temperature, uint32_t max_subcompactions,
             std::vector<FileMetaData*> grandparents,
             bool manual_compaction = false, double score = -1,
             bool deletion_compaction = false,
@@ -162,7 +163,7 @@ class Compaction {
  CompressionType output_compression() const { return output_compression_; }

  // What compression options for output
-  CompressionOptions output_compression_opts() const {
+  const CompressionOptions& output_compression_opts() const {
    return output_compression_opts_;
  }

@@ -223,10 +224,10 @@ class Compaction {
  // How many total levels are there?
  int number_levels() const { return number_levels_; }

-  // Return the ImmutableCFOptions that should be used throughout the compaction
+  // Return the ImmutableOptions that should be used throughout the compaction
  // procedure
-  const ImmutableCFOptions* immutable_cf_options() const {
-    return &immutable_cf_options_;
+  const ImmutableOptions* immutable_options() const {
+    return &immutable_options_;
  }

  // Return the MutableCFOptions that should be used throughout the compaction
@@ -266,6 +267,11 @@ class Compaction {
  // Should this compaction be broken up into smaller ones run in parallel?
  bool ShouldFormSubcompactions() const;

+  // Returns true iff at least one input file references a blob file.
+  //
+  // PRE: input version has been set.
+  bool DoesInputReferenceBlobFiles() const;
+
  // test function to validate the functionality of IsBottommostLevel()
  // function -- determines if compaction with inputs and storage is bottommost
  static bool TEST_IsBottommostLevel(
@@ -294,10 +300,22 @@ class Compaction {

  uint64_t max_compaction_bytes() const { return max_compaction_bytes_; }

+  Temperature output_temperature() const { return output_temperature_; }
+
  uint32_t max_subcompactions() const { return max_subcompactions_; }

  uint64_t MinInputFileOldestAncesterTime() const;

+  // Called by DBImpl::NotifyOnCompactionCompleted to make sure number of
+  // compaction begin and compaction completion callbacks match.
+  void SetNotifyOnCompactionCompleted() {
+    notify_on_compaction_completion_ = true;
+  }
+
+  bool ShouldNotifyOnCompactionCompleted() const {
+    return notify_on_compaction_completion_;
+  }
+
 private:
  // mark (or clear) all files that are being compacted
  void MarkFilesBeingCompacted(bool mark_as_compacted);
@@ -330,7 +348,7 @@ class Compaction {
  uint64_t max_output_file_size_;
  uint64_t max_compaction_bytes_;
  uint32_t max_subcompactions_;
-  const ImmutableCFOptions immutable_cf_options_;
+  const ImmutableOptions immutable_options_;
  const MutableCFOptions mutable_cf_options_;
  Version* input_version_;
  VersionEdit edit_;
@@ -341,6 +359,7 @@ class Compaction {
  const uint32_t output_path_id_;
  CompressionType output_compression_;
  CompressionOptions output_compression_opts_;
+  Temperature output_temperature_;
  // If true, then the compaction can be done by simply deleting input files.
  const bool deletion_compaction_;

@@ -381,6 +400,10 @@ class Compaction {

  // Reason for compaction
  CompactionReason compaction_reason_;
+
+  // Notify on compaction completion only if listener was notified on compaction
+  // begin.
+  bool notify_on_compaction_completion_;
 };

 // Return sum of sizes of all files in `files`.
@@ -5,6 +5,8 @@

 #pragma once

+#include <cstdint>
+
 #include "rocksdb/rocksdb_namespace.h"

 struct CompactionIterationStats {
@@ -38,4 +40,6 @@ struct CompactionIterationStats {
  // Blob related statistics
  uint64_t num_blobs_read = 0;
  uint64_t total_blob_bytes_read = 0;
+  uint64_t num_blobs_relocated = 0;
+  uint64_t total_blob_bytes_relocated = 0;
 };
@@ -11,29 +11,13 @@
 #include "db/blob/blob_file_builder.h"
 #include "db/blob/blob_index.h"
 #include "db/snapshot_checker.h"
+#include "logging/logging.h"
 #include "port/likely.h"
 #include "rocksdb/listener.h"
 #include "table/internal_iterator.h"
 #include "test_util/sync_point.h"

-#define DEFINITELY_IN_SNAPSHOT(seq, snapshot)                       \
-  ((seq) <= (snapshot) &&                                           \
-   (snapshot_checker_ == nullptr ||                                 \
-    LIKELY(snapshot_checker_->CheckInSnapshot((seq), (snapshot)) == \
-           SnapshotCheckerResult::kInSnapshot)))
-
-#define DEFINITELY_NOT_IN_SNAPSHOT(seq, snapshot)                     \
-  ((seq) > (snapshot) ||                                              \
-   (snapshot_checker_ != nullptr &&                                   \
-    UNLIKELY(snapshot_checker_->CheckInSnapshot((seq), (snapshot)) == \
-             SnapshotCheckerResult::kNotInSnapshot)))
-
-#define IN_EARLIEST_SNAPSHOT(seq) \
-  ((seq) <= earliest_snapshot_ && \
-   (snapshot_checker_ == nullptr || LIKELY(IsInEarliestSnapshot(seq))))
-
 namespace ROCKSDB_NAMESPACE {
-
 CompactionIterator::CompactionIterator(
    InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
    SequenceNumber last_sequence, std::vector<SequenceNumber>* snapshots,
@@ -46,6 +30,7 @@ CompactionIterator::CompactionIterator(
    const std::atomic<bool>* shutting_down,
    const SequenceNumber preserve_deletes_seqnum,
    const std::atomic<int>* manual_compaction_paused,
+    const std::atomic<bool>* manual_compaction_canceled,
    const std::shared_ptr<Logger> info_log,
    const std::string* full_history_ts_low)
    : CompactionIterator(
@@ -56,7 +41,8 @@ CompactionIterator::CompactionIterator(
          std::unique_ptr<CompactionProxy>(
              compaction ? new RealCompaction(compaction) : nullptr),
          compaction_filter, shutting_down, preserve_deletes_seqnum,
-          manual_compaction_paused, info_log, full_history_ts_low) {}
+          manual_compaction_paused, manual_compaction_canceled, info_log,
+          full_history_ts_low) {}

 CompactionIterator::CompactionIterator(
    InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
@@ -71,9 +57,11 @@ CompactionIterator::CompactionIterator(
    const std::atomic<bool>* shutting_down,
    const SequenceNumber preserve_deletes_seqnum,
    const std::atomic<int>* manual_compaction_paused,
+    const std::atomic<bool>* manual_compaction_canceled,
    const std::shared_ptr<Logger> info_log,
    const std::string* full_history_ts_low)
-    : input_(input),
+    : input_(input, cmp,
+             !compaction || compaction->DoesInputReferenceBlobFiles()),
      cmp_(cmp),
      merge_helper_(merge_helper),
      snapshots_(snapshots),
@@ -89,6 +77,7 @@ CompactionIterator::CompactionIterator(
      compaction_filter_(compaction_filter),
      shutting_down_(shutting_down),
      manual_compaction_paused_(manual_compaction_paused),
+      manual_compaction_canceled_(manual_compaction_canceled),
      preserve_deletes_seqnum_(preserve_deletes_seqnum),
      info_log_(info_log),
      allow_data_in_errors_(allow_data_in_errors),
@@ -100,8 +89,8 @@ CompactionIterator::CompactionIterator(
      blob_garbage_collection_cutoff_file_number_(
          ComputeBlobGarbageCollectionCutoffFileNumber(compaction_.get())),
      current_key_committed_(false),
-      cmp_with_history_ts_low_(0) {
-  assert(compaction_filter_ == nullptr || compaction_ != nullptr);
+      cmp_with_history_ts_low_(0),
+      level_(compaction_ == nullptr ? 0 : compaction_->level()) {
  assert(snapshots_ != nullptr);
  bottommost_level_ = compaction_ == nullptr
                          ? false
@@ -130,13 +119,13 @@ CompactionIterator::CompactionIterator(
  assert(timestamp_size_ == 0 || !full_history_ts_low_ ||
         timestamp_size_ == full_history_ts_low_->size());
 #endif
-  input_->SetPinnedItersMgr(&pinned_iters_mgr_);
+  input_.SetPinnedItersMgr(&pinned_iters_mgr_);
  TEST_SYNC_POINT_CALLBACK("CompactionIterator:AfterInit", compaction_.get());
 }

 CompactionIterator::~CompactionIterator() {
  // input_ Iterator lifetime is longer than pinned_iters_mgr_ lifetime
-  input_->SetPinnedItersMgr(nullptr);
+  input_.SetPinnedItersMgr(nullptr);
 }

 void CompactionIterator::ResetRecordCounts() {
@@ -189,7 +178,7 @@ void CompactionIterator::Next() {
    // Only advance the input iterator if there is no merge output and the
    // iterator is not already at the next record.
    if (!at_next_) {
-      input_->Next();
+      AdvanceInputIter();
    }
    NextFromInput();
  }
@@ -232,7 +221,7 @@ bool CompactionIterator::InvokeFilterIfNeeded(bool* need_skip,
    if (kTypeBlobIndex == ikey_.type) {
      blob_value_.Reset();
      filter = compaction_filter_->FilterBlobByKey(
-          compaction_->level(), filter_key, &compaction_filter_value_,
+          level_, filter_key, &compaction_filter_value_,
          compaction_filter_skip_until_.rep());
      if (CompactionFilter::Decision::kUndetermined == filter &&
          !compaction_filter_->IsStackedBlobDbInternalCompactionFilter()) {
@@ -251,6 +240,12 @@ bool CompactionIterator::InvokeFilterIfNeeded(bool* need_skip,
          valid_ = false;
          return false;
        }
+        if (compaction_ == nullptr) {
+          status_ =
+              Status::Corruption("Unexpected blob index outside of compaction");
+          valid_ = false;
+          return false;
+        }
        const Version* const version = compaction_->input_version();
        assert(version);

@@ -271,7 +266,7 @@ bool CompactionIterator::InvokeFilterIfNeeded(bool* need_skip,
    }
    if (CompactionFilter::Decision::kUndetermined == filter) {
      filter = compaction_filter_->FilterV2(
-          compaction_->level(), filter_key, value_type,
+          level_, filter_key, value_type,
          blob_value_.empty() ? value_ : blob_value_, &compaction_filter_value_,
          compaction_filter_skip_until_.rep());
    }
@@ -350,10 +345,10 @@ void CompactionIterator::NextFromInput() {
  at_next_ = false;
  valid_ = false;

-  while (!valid_ && input_->Valid() && !IsPausingManualCompaction() &&
+  while (!valid_ && input_.Valid() && !IsPausingManualCompaction() &&
         !IsShuttingDown()) {
-    key_ = input_->key();
-    value_ = input_->value();
+    key_ = input_.key();
+    value_ = input_.value();
    iter_stats_.num_input_records++;

    Status pik_status = ParseInternalKey(key_, &ikey_, allow_data_in_errors_);
@@ -501,11 +496,11 @@ void CompactionIterator::NextFromInput() {
                        "Unexpected key type %d for compaction output",
                        ikey_.type);
      }
-      assert(current_user_key_snapshot_ == last_snapshot);
-      if (current_user_key_snapshot_ != last_snapshot) {
+      assert(current_user_key_snapshot_ >= last_snapshot);
+      if (current_user_key_snapshot_ < last_snapshot) {
        ROCKS_LOG_FATAL(info_log_,
                        "current_user_key_snapshot_ (%" PRIu64
-                        ") != last_snapshot (%" PRIu64 ")",
+                        ") < last_snapshot (%" PRIu64 ")",
                        current_user_key_snapshot_, last_snapshot);
      }

@@ -549,35 +544,61 @@ void CompactionIterator::NextFromInput() {
      // we can choose how to handle such a combinations of operations.  We will
      // try to compact out as much as we can in these cases.
      // We will report counts on these anomalous cases.
+      //
+      // Note: If timestamp is enabled, then record will be eligible for
+      // deletion, only if, along with above conditions (Rule 1 and Rule 2)
+      // full_history_ts_low_ is specified and timestamp for that key is less
+      // than *full_history_ts_low_. If it's not eligible for deletion, then we
+      // will output the SingleDelete. For Optimization 3 also, if
+      // full_history_ts_low_ is specified and timestamp for the key is less
+      // than *full_history_ts_low_ then only optimization will be applied.

      // The easiest way to process a SingleDelete during iteration is to peek
      // ahead at the next key.
+      const bool is_timestamp_eligible_for_gc =
+          (timestamp_size_ == 0 ||
+           (full_history_ts_low_ && cmp_with_history_ts_low_ < 0));
+
      ParsedInternalKey next_ikey;
-      input_->Next();
+      AdvanceInputIter();

      // Check whether the next key exists, is not corrupt, and is the same key
      // as the single delete.
-      if (input_->Valid() &&
-          ParseInternalKey(input_->key(), &next_ikey, allow_data_in_errors_)
+      if (input_.Valid() &&
+          ParseInternalKey(input_.key(), &next_ikey, allow_data_in_errors_)
              .ok() &&
-          cmp_->Equal(ikey_.user_key, next_ikey.user_key)) {
+          cmp_->EqualWithoutTimestamp(ikey_.user_key, next_ikey.user_key)) {
+#ifndef NDEBUG
+        const Compaction* c =
+            compaction_ ? compaction_->real_compaction() : nullptr;
+#endif
+        TEST_SYNC_POINT_CALLBACK(
+            "CompactionIterator::NextFromInput:SingleDelete:1",
+            const_cast<Compaction*>(c));
        // Check whether the next key belongs to the same snapshot as the
        // SingleDelete.
        if (prev_snapshot == 0 ||
-            DEFINITELY_NOT_IN_SNAPSHOT(next_ikey.sequence, prev_snapshot)) {
+            DefinitelyNotInSnapshot(next_ikey.sequence, prev_snapshot)) {
+          TEST_SYNC_POINT_CALLBACK(
+              "CompactionIterator::NextFromInput:SingleDelete:2", nullptr);
          if (next_ikey.type == kTypeSingleDeletion) {
-            // We encountered two SingleDeletes in a row.  This could be due to
-            // unexpected user input.
-            // Skip the first SingleDelete and let the next iteration decide how
-            // to handle the second SingleDelete
+            // We encountered two SingleDeletes for same key in a row. This
+            // could be due to unexpected user input. Skip the first
+            // SingleDelete and let the next iteration decide how to handle the
+            // second SingleDelete

            // First SingleDelete has been skipped since we already called
-            // input_->Next().
+            // input_.Next().
            ++iter_stats_.num_record_drop_obsolete;
            ++iter_stats_.num_single_del_mismatch;
+          } else if (!is_timestamp_eligible_for_gc) {
+            // We cannot drop the SingleDelete as timestamp is enabled, and
+            // timestamp of this key is greater than or equal to
+            // *full_history_ts_low_. We will output the SingleDelete.
+            valid_ = true;
          } else if (has_outputted_key_ ||
-                     DEFINITELY_IN_SNAPSHOT(
-                         ikey_.sequence, earliest_write_conflict_snapshot_)) {
+                     DefinitelyInSnapshot(ikey_.sequence,
+                                          earliest_write_conflict_snapshot_)) {
            // Found a matching value, we can drop the single delete and the
            // value.  It is safe to drop both records since we've already
            // outputted a key in this snapshot, or there is no earlier
@@ -594,9 +615,9 @@ void CompactionIterator::NextFromInput() {

            ++iter_stats_.num_record_drop_hidden;
            ++iter_stats_.num_record_drop_obsolete;
-            // Already called input_->Next() once.  Call it a second time to
+            // Already called input_.Next() once.  Call it a second time to
            // skip past the second key.
-            input_->Next();
+            AdvanceInputIter();
          } else {
            // Found a matching value, but we cannot drop both keys since
            // there is an earlier snapshot and we need to leave behind a record
@@ -610,6 +631,9 @@ void CompactionIterator::NextFromInput() {
            // Set up the Put to be outputted in the next iteration.
            // (Optimization 3).
            clear_and_output_next_key_ = true;
+            TEST_SYNC_POINT_CALLBACK(
+                "CompactionIterator::NextFromInput:KeepSDForWW",
+                /*arg=*/nullptr);
          }
        } else {
          // We hit the next snapshot without hitting a put, so the iterator
@@ -625,9 +649,11 @@ void CompactionIterator::NextFromInput() {
        // iteration. If the next key is corrupt, we return before the
        // comparison, so the value of has_current_user_key does not matter.
        has_current_user_key_ = false;
-        if (compaction_ != nullptr && IN_EARLIEST_SNAPSHOT(ikey_.sequence) &&
+        if (compaction_ != nullptr &&
+            DefinitelyInSnapshot(ikey_.sequence, earliest_snapshot_) &&
            compaction_->KeyNotExistsBeyondOutputLevel(ikey_.user_key,
-                                                       &level_ptrs_)) {
+                                                       &level_ptrs_) &&
+            is_timestamp_eligible_for_gc) {
          // Key doesn't exist outside of this range.
          // Can compact out this SingleDelete.
          ++iter_stats_.num_record_drop_obsolete;
@@ -664,12 +690,12 @@ void CompactionIterator::NextFromInput() {
      }

      ++iter_stats_.num_record_drop_hidden;  // rule (A)
-      input_->Next();
+      AdvanceInputIter();
    } else if (compaction_ != nullptr &&
               (ikey_.type == kTypeDeletion ||
                (ikey_.type == kTypeDeletionWithTimestamp &&
                 cmp_with_history_ts_low_ < 0)) &&
-               IN_EARLIEST_SNAPSHOT(ikey_.sequence) &&
+               DefinitelyInSnapshot(ikey_.sequence, earliest_snapshot_) &&
               ikeyNotNeededForIncrementalSnapshot() &&
               compaction_->KeyNotExistsBeyondOutputLevel(ikey_.user_key,
                                                          &level_ptrs_)) {
@@ -700,7 +726,7 @@ void CompactionIterator::NextFromInput() {
      if (!bottommost_level_) {
        ++iter_stats_.num_optimized_del_drop_obsolete;
      }
-      input_->Next();
+      AdvanceInputIter();
    } else if ((ikey_.type == kTypeDeletion ||
                (ikey_.type == kTypeDeletionWithTimestamp &&
                 cmp_with_history_ts_low_ < 0)) &&
@@ -711,7 +737,14 @@ void CompactionIterator::NextFromInput() {
      assert(!compaction_ || compaction_->KeyNotExistsBeyondOutputLevel(
                                 ikey_.user_key, &level_ptrs_));
      ParsedInternalKey next_ikey;
-      input_->Next();
+      AdvanceInputIter();
+#ifndef NDEBUG
+      const Compaction* c =
+          compaction_ ? compaction_->real_compaction() : nullptr;
+#endif
+      TEST_SYNC_POINT_CALLBACK(
+          "CompactionIterator::NextFromInput:BottommostDelete:1",
+          const_cast<Compaction*>(c));
      // Skip over all versions of this key that happen to occur in the same
      // snapshot range as the delete.
      //
@@ -719,18 +752,18 @@ void CompactionIterator::NextFromInput() {
      // considered to have a different user key unless the timestamp is older
      // than *full_history_ts_low_.
      while (!IsPausingManualCompaction() && !IsShuttingDown() &&
-             input_->Valid() &&
-             (ParseInternalKey(input_->key(), &next_ikey, allow_data_in_errors_)
+             input_.Valid() &&
+             (ParseInternalKey(input_.key(), &next_ikey, allow_data_in_errors_)
                  .ok()) &&
             cmp_->EqualWithoutTimestamp(ikey_.user_key, next_ikey.user_key) &&
             (prev_snapshot == 0 ||
-              DEFINITELY_NOT_IN_SNAPSHOT(next_ikey.sequence, prev_snapshot))) {
-        input_->Next();
+              DefinitelyNotInSnapshot(next_ikey.sequence, prev_snapshot))) {
+        AdvanceInputIter();
      }
      // If you find you still need to output a row with this key, we need to output the
      // delete too
-      if (input_->Valid() &&
-          (ParseInternalKey(input_->key(), &next_ikey, allow_data_in_errors_)
+      if (input_.Valid() &&
+          (ParseInternalKey(input_.key(), &next_ikey, allow_data_in_errors_)
               .ok()) &&
          cmp_->EqualWithoutTimestamp(ikey_.user_key, next_ikey.user_key)) {
        valid_ = true;
@@ -744,13 +777,15 @@ void CompactionIterator::NextFromInput() {
      }

      pinned_iters_mgr_.StartPinning();
+      Version* version = compaction_ ? compaction_->input_version() : nullptr;
+
      // We know the merge type entry is not hidden, otherwise we would
      // have hit (A)
      // We encapsulate the merge related state machine in a different
      // object to minimize change to the existing flow.
-      Status s =
-          merge_helper_->MergeUntil(input_, range_del_agg_, prev_snapshot,
-                                    bottommost_level_, allow_data_in_errors_);
+      Status s = merge_helper_->MergeUntil(&input_, range_del_agg_,
+                                           prev_snapshot, bottommost_level_,
+                                           allow_data_in_errors_, version);
      merge_out_iter_.SeekToFirst();

      if (!s.ok() && !s.IsMergeInProgress()) {
@@ -793,14 +828,14 @@ void CompactionIterator::NextFromInput() {
      if (should_delete) {
        ++iter_stats_.num_record_drop_hidden;
        ++iter_stats_.num_record_drop_range_del;
-        input_->Next();
+        AdvanceInputIter();
      } else {
        valid_ = true;
      }
    }

    if (need_skip) {
-      input_->Seek(skip_until);
+      SkipUntil(skip_until);
    }
  }

@@ -902,6 +937,9 @@ void CompactionIterator::GarbageCollectBlobIfNeeded() {
    ++iter_stats_.num_blobs_read;
    iter_stats_.total_blob_bytes_read += bytes_read;

+    ++iter_stats_.num_blobs_relocated;
+    iter_stats_.total_blob_bytes_relocated += blob_index.size();
+
    value_ = blob_value_;

    if (ExtractLargeValueIfNeededImpl()) {
@@ -965,9 +1003,14 @@ void CompactionIterator::PrepareOutput() {
    if (valid_ && compaction_ != nullptr &&
        !compaction_->allow_ingest_behind() &&
        ikeyNotNeededForIncrementalSnapshot() && bottommost_level_ &&
-        IN_EARLIEST_SNAPSHOT(ikey_.sequence) && ikey_.type != kTypeMerge) {
-      assert(ikey_.type != kTypeDeletion && ikey_.type != kTypeSingleDeletion);
-      if (ikey_.type == kTypeDeletion || ikey_.type == kTypeSingleDeletion) {
+        DefinitelyInSnapshot(ikey_.sequence, earliest_snapshot_) &&
+        ikey_.type != kTypeMerge) {
+      assert(ikey_.type != kTypeDeletion);
+      assert(ikey_.type != kTypeSingleDeletion ||
+             (timestamp_size_ || full_history_ts_low_));
+      if (ikey_.type == kTypeDeletion ||
+          (ikey_.type == kTypeSingleDeletion &&
+           (!timestamp_size_ || !full_history_ts_low_))) {
        ROCKS_LOG_FATAL(info_log_,
                        "Unexpected key type %d for seq-zero optimization",
                        ikey_.type);
@@ -1041,7 +1084,7 @@ inline bool CompactionIterator::ikeyNotNeededForIncrementalSnapshot() {
         (ikey_.sequence < preserve_deletes_seqnum_);
 }

-bool CompactionIterator::IsInEarliestSnapshot(SequenceNumber sequence) {
+bool CompactionIterator::IsInCurrentEarliestSnapshot(SequenceNumber sequence) {
  assert(snapshot_checker_ != nullptr);
  bool pre_condition = (earliest_snapshot_ == kMaxSequenceNumber ||
                        (earliest_snapshot_iter_ != snapshots_->end() &&
@@ -24,6 +24,51 @@ namespace ROCKSDB_NAMESPACE {

 class BlobFileBuilder;

+// A wrapper of internal iterator whose purpose is to count how
+// many entries there are in the iterator.
+class SequenceIterWrapper : public InternalIterator {
+ public:
+  SequenceIterWrapper(InternalIterator* iter, const Comparator* cmp,
+                      bool need_count_entries)
+      : icmp_(cmp, /*named=*/false),
+        inner_iter_(iter),
+        need_count_entries_(need_count_entries) {}
+  bool Valid() const override { return inner_iter_->Valid(); }
+  Status status() const override { return inner_iter_->status(); }
+  void Next() override {
+    num_itered_++;
+    inner_iter_->Next();
+  }
+  void Seek(const Slice& target) override {
+    if (!need_count_entries_) {
+      inner_iter_->Seek(target);
+    } else {
+      // For flush cases, we need to count total number of entries, so we
+      // do Next() rather than Seek().
+      while (inner_iter_->Valid() &&
+             icmp_.Compare(inner_iter_->key(), target) < 0) {
+        Next();
+      }
+    }
+  }
+  Slice key() const override { return inner_iter_->key(); }
+  Slice value() const override { return inner_iter_->value(); }
+
+  // Unused InternalIterator methods
+  void SeekToFirst() override { assert(false); }
+  void Prev() override { assert(false); }
+  void SeekForPrev(const Slice& /* target */) override { assert(false); }
+  void SeekToLast() override { assert(false); }
+
+  uint64_t num_itered() const { return num_itered_; }
+
+ private:
+  InternalKeyComparator icmp_;
+  InternalIterator* inner_iter_;  // not owned
+  uint64_t num_itered_ = 0;
+  bool need_count_entries_;
+};
+
 class CompactionIterator {
 public:
  // A wrapper around Compaction. Has a much smaller interface, only what
@@ -52,6 +97,10 @@ class CompactionIterator {
    virtual double blob_garbage_collection_age_cutoff() const = 0;

    virtual Version* input_version() const = 0;
+
+    virtual bool DoesInputReferenceBlobFiles() const = 0;
+
+    virtual const Compaction* real_compaction() const = 0;
  };

  class RealCompaction : public CompactionProxy {
@@ -59,7 +108,7 @@ class CompactionIterator {
    explicit RealCompaction(const Compaction* compaction)
        : compaction_(compaction) {
      assert(compaction_);
-      assert(compaction_->immutable_cf_options());
+      assert(compaction_->immutable_options());
      assert(compaction_->mutable_cf_options());
    }

@@ -81,11 +130,11 @@ class CompactionIterator {
    }

    bool allow_ingest_behind() const override {
-      return compaction_->immutable_cf_options()->allow_ingest_behind;
+      return compaction_->immutable_options()->allow_ingest_behind;
    }

    bool preserve_deletes() const override {
-      return compaction_->immutable_cf_options()->preserve_deletes;
+      return compaction_->immutable_options()->preserve_deletes;
    }

    bool enable_blob_garbage_collection() const override {
@@ -101,44 +150,50 @@ class CompactionIterator {
      return compaction_->input_version();
    }

+    bool DoesInputReferenceBlobFiles() const override {
+      return compaction_->DoesInputReferenceBlobFiles();
+    }
+
+    const Compaction* real_compaction() const override { return compaction_; }
+
   private:
    const Compaction* compaction_;
  };

-  CompactionIterator(InternalIterator* input, const Comparator* cmp,
-                     MergeHelper* merge_helper, SequenceNumber last_sequence,
-                     std::vector<SequenceNumber>* snapshots,
-                     SequenceNumber earliest_write_conflict_snapshot,
-                     const SnapshotChecker* snapshot_checker, Env* env,
-                     bool report_detailed_time, bool expect_valid_internal_key,
-                     CompactionRangeDelAggregator* range_del_agg,
-                     BlobFileBuilder* blob_file_builder,
-                     bool allow_data_in_errors,
-                     const Compaction* compaction = nullptr,
-                     const CompactionFilter* compaction_filter = nullptr,
-                     const std::atomic<bool>* shutting_down = nullptr,
-                     const SequenceNumber preserve_deletes_seqnum = 0,
-                     const std::atomic<int>* manual_compaction_paused = nullptr,
-                     const std::shared_ptr<Logger> info_log = nullptr,
-                     const std::string* full_history_ts_low = nullptr);
+  CompactionIterator(
+      InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
+      SequenceNumber last_sequence, std::vector<SequenceNumber>* snapshots,
+      SequenceNumber earliest_write_conflict_snapshot,
+      const SnapshotChecker* snapshot_checker, Env* env,
+      bool report_detailed_time, bool expect_valid_internal_key,
+      CompactionRangeDelAggregator* range_del_agg,
+      BlobFileBuilder* blob_file_builder, bool allow_data_in_errors,
+      const Compaction* compaction = nullptr,
+      const CompactionFilter* compaction_filter = nullptr,
+      const std::atomic<bool>* shutting_down = nullptr,
+      const SequenceNumber preserve_deletes_seqnum = 0,
+      const std::atomic<int>* manual_compaction_paused = nullptr,
+      const std::atomic<bool>* manual_compaction_canceled = nullptr,
+      const std::shared_ptr<Logger> info_log = nullptr,
+      const std::string* full_history_ts_low = nullptr);

  // Constructor with custom CompactionProxy, used for tests.
-  CompactionIterator(InternalIterator* input, const Comparator* cmp,
-                     MergeHelper* merge_helper, SequenceNumber last_sequence,
-                     std::vector<SequenceNumber>* snapshots,
-                     SequenceNumber earliest_write_conflict_snapshot,
-                     const SnapshotChecker* snapshot_checker, Env* env,
-                     bool report_detailed_time, bool expect_valid_internal_key,
-                     CompactionRangeDelAggregator* range_del_agg,
-                     BlobFileBuilder* blob_file_builder,
-                     bool allow_data_in_errors,
-                     std::unique_ptr<CompactionProxy> compaction,
-                     const CompactionFilter* compaction_filter = nullptr,
-                     const std::atomic<bool>* shutting_down = nullptr,
-                     const SequenceNumber preserve_deletes_seqnum = 0,
-                     const std::atomic<int>* manual_compaction_paused = nullptr,
-                     const std::shared_ptr<Logger> info_log = nullptr,
-                     const std::string* full_history_ts_low = nullptr);
+  CompactionIterator(
+      InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
+      SequenceNumber last_sequence, std::vector<SequenceNumber>* snapshots,
+      SequenceNumber earliest_write_conflict_snapshot,
+      const SnapshotChecker* snapshot_checker, Env* env,
+      bool report_detailed_time, bool expect_valid_internal_key,
+      CompactionRangeDelAggregator* range_del_agg,
+      BlobFileBuilder* blob_file_builder, bool allow_data_in_errors,
+      std::unique_ptr<CompactionProxy> compaction,
+      const CompactionFilter* compaction_filter = nullptr,
+      const std::atomic<bool>* shutting_down = nullptr,
+      const SequenceNumber preserve_deletes_seqnum = 0,
+      const std::atomic<int>* manual_compaction_paused = nullptr,
+      const std::atomic<bool>* manual_compaction_canceled = nullptr,
+      const std::shared_ptr<Logger> info_log = nullptr,
+      const std::string* full_history_ts_low = nullptr);

  ~CompactionIterator();

@@ -162,6 +217,7 @@ class CompactionIterator {
  bool Valid() const { return valid_; }
  const Slice& user_key() const { return current_user_key_; }
  const CompactionIterationStats& iter_stats() const { return iter_stats_; }
+  uint64_t num_input_entry_scanned() const { return input_.num_itered(); }

 private:
  // Processes the input stream to find the next output
@@ -215,7 +271,13 @@ class CompactionIterator {
               SnapshotCheckerResult::kInSnapshot;
  }

-  bool IsInEarliestSnapshot(SequenceNumber sequence);
+  bool IsInCurrentEarliestSnapshot(SequenceNumber sequence);
+
+  bool DefinitelyInSnapshot(SequenceNumber seq, SequenceNumber snapshot);
+
+  bool DefinitelyNotInSnapshot(SequenceNumber seq, SequenceNumber snapshot);
+
+  bool InCurrentEarliestSnapshot(SequenceNumber seq);

  // Extract user-defined timestamp from user key if possible and compare it
  // with *full_history_ts_low_ if applicable.
@@ -234,7 +296,7 @@ class CompactionIterator {
  static uint64_t ComputeBlobGarbageCollectionCutoffFileNumber(
      const CompactionProxy* compaction);

-  InternalIterator* input_;
+  SequenceIterWrapper input_;
  const Comparator* cmp_;
  MergeHelper* merge_helper_;
  const std::vector<SequenceNumber>* snapshots_;
@@ -257,6 +319,7 @@ class CompactionIterator {
  const CompactionFilter* compaction_filter_;
  const std::atomic<bool>* shutting_down_;
  const std::atomic<int>* manual_compaction_paused_;
+  const std::atomic<bool>* manual_compaction_canceled_;
  const SequenceNumber preserve_deletes_seqnum_;
  bool bottommost_level_;
  bool valid_ = false;
@@ -340,6 +403,12 @@ class CompactionIterator {
  // Saved result of ucmp->CompareTimestamp(current_ts_, *full_history_ts_low_)
  int cmp_with_history_ts_low_;

+  const int level_;
+
+  void AdvanceInputIter() { input_.Next(); }
+
+  void SkipUntil(const Slice& skip_until) { input_.Seek(skip_until); }
+
  bool IsShuttingDown() {
    // This is a best-effort facility, so memory_order_relaxed is sufficient.
    return shutting_down_ && shutting_down_->load(std::memory_order_relaxed);
@@ -347,8 +416,33 @@ class CompactionIterator {

  bool IsPausingManualCompaction() {
    // This is a best-effort facility, so memory_order_relaxed is sufficient.
-    return manual_compaction_paused_ &&
-           manual_compaction_paused_->load(std::memory_order_relaxed) > 0;
+    return (manual_compaction_paused_ &&
+            manual_compaction_paused_->load(std::memory_order_relaxed) > 0) ||
+           (manual_compaction_canceled_ &&
+            manual_compaction_canceled_->load(std::memory_order_relaxed));
  }
 };
+
+inline bool CompactionIterator::DefinitelyInSnapshot(SequenceNumber seq,
+                                                     SequenceNumber snapshot) {
+  return ((seq) <= (snapshot) &&
+          (snapshot_checker_ == nullptr ||
+           LIKELY(snapshot_checker_->CheckInSnapshot((seq), (snapshot)) ==
+                  SnapshotCheckerResult::kInSnapshot)));
+}
+
+inline bool CompactionIterator::DefinitelyNotInSnapshot(
+    SequenceNumber seq, SequenceNumber snapshot) {
+  return ((seq) > (snapshot) ||
+          (snapshot_checker_ != nullptr &&
+           UNLIKELY(snapshot_checker_->CheckInSnapshot((seq), (snapshot)) ==
+                    SnapshotCheckerResult::kNotInSnapshot)));
+}
+
+inline bool CompactionIterator::InCurrentEarliestSnapshot(SequenceNumber seq) {
+  return ((seq) <= earliest_snapshot_ &&
+          (snapshot_checker_ == nullptr ||
+           LIKELY(IsInCurrentEarliestSnapshot(seq))));
+}
+
 }  // namespace ROCKSDB_NAMESPACE
@@ -3,15 +3,17 @@
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).

+#include "db/compaction/compaction_iterator.h"

 #include <string>
 #include <vector>

-#include "db/compaction/compaction_iterator.h"
+#include "db/dbformat.h"
 #include "port/port.h"
 #include "test_util/testharness.h"
 #include "test_util/testutil.h"
 #include "util/string_util.h"
+#include "util/vector_iterator.h"
 #include "utilities/merge_operators.h"

 namespace ROCKSDB_NAMESPACE {
@@ -86,7 +88,7 @@ class FilterAllKeysCompactionFilter : public CompactionFilter {
  const char* Name() const override { return "AllKeysCompactionFilter"; }
 };

-class LoggingForwardVectorIterator : public InternalIterator {
+class LoggingForwardVectorIterator : public VectorIterator {
 public:
  struct Action {
    enum class Type {
@@ -108,22 +110,19 @@ class LoggingForwardVectorIterator : public InternalIterator {

  LoggingForwardVectorIterator(const std::vector<std::string>& keys,
                               const std::vector<std::string>& values)
-      : keys_(keys), values_(values), current_(keys.size()) {
-    assert(keys_.size() == values_.size());
+      : VectorIterator(keys, values) {
+    current_ = keys_.size();
  }

-  bool Valid() const override { return current_ < keys_.size(); }
-
  void SeekToFirst() override {
    log.emplace_back(Action::Type::SEEK_TO_FIRST);
-    current_ = 0;
+    VectorIterator::SeekToFirst();
  }
  void SeekToLast() override { assert(false); }

  void Seek(const Slice& target) override {
    log.emplace_back(Action::Type::SEEK, target.ToString());
-    current_ = std::lower_bound(keys_.begin(), keys_.end(), target.ToString()) -
-               keys_.begin();
+    VectorIterator::Seek(target);
  }

  void SeekForPrev(const Slice& /*target*/) override { assert(false); }
@@ -131,27 +130,20 @@ class LoggingForwardVectorIterator : public InternalIterator {
  void Next() override {
    assert(Valid());
    log.emplace_back(Action::Type::NEXT);
-    current_++;
+    VectorIterator::Next();
  }
  void Prev() override { assert(false); }

  Slice key() const override {
    assert(Valid());
-    return Slice(keys_[current_]);
+    return VectorIterator::key();
  }
  Slice value() const override {
    assert(Valid());
-    return Slice(values_[current_]);
+    return VectorIterator::value();
  }

-  Status status() const override { return Status::OK(); }
-
  std::vector<Action> log;
-
- private:
-  std::vector<std::string> keys_;
-  std::vector<std::string> values_;
-  size_t current_;
 };

 class FakeCompaction : public CompactionIterator::CompactionProxy {
@@ -182,6 +174,10 @@ class FakeCompaction : public CompactionIterator::CompactionProxy {

  Version* input_version() const override { return nullptr; }

+  bool DoesInputReferenceBlobFiles() const override { return false; }
+
+  const Compaction* real_compaction() const override { return nullptr; }
+
  bool key_not_exists_beyond_output_level = false;

  bool is_bottommost_level = false;
@@ -240,7 +236,7 @@ class CompactionIteratorTest : public testing::TestWithParam<bool> {
      bool key_not_exists_beyond_output_level = false,
      const std::string* full_history_ts_low = nullptr) {
    std::unique_ptr<InternalIterator> unfragmented_range_del_iter(
-        new test::VectorIterator(range_del_ks, range_del_vs));
+        new VectorIterator(range_del_ks, range_del_vs, &icmp_));
    auto tombstone_list = std::make_shared<FragmentedRangeTombstoneList>(
        std::move(unfragmented_range_del_iter), icmp_);
    std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter(
@@ -282,7 +278,8 @@ class CompactionIteratorTest : public testing::TestWithParam<bool> {
        range_del_agg_.get(), nullptr /* blob_file_builder */,
        true /*allow_data_in_errors*/, std::move(compaction), filter,
        &shutting_down_, /*preserve_deletes_seqnum=*/0,
-        /*manual_compaction_paused=*/nullptr, /*info_log=*/nullptr,
+        /*manual_compaction_paused=*/nullptr,
+        /*manual_compaction_canceled=*/nullptr, /*info_log=*/nullptr,
        full_history_ts_low));
  }

@@ -1253,6 +1250,101 @@ TEST_P(CompactionIteratorTsGcTest, RewriteTs) {
  }
 }

+TEST_P(CompactionIteratorTsGcTest, SingleDeleteNoKeyEligibleForGC) {
+  constexpr char user_key[][2] = {{'a', '\0'}, {'b', '\0'}};
+  const std::vector<std::string> input_keys = {
+      test::KeyStr(/*ts=*/104, user_key[0], /*seq=*/4, kTypeSingleDeletion),
+      test::KeyStr(/*ts=*/103, user_key[0], /*seq=*/3, kTypeValue),
+      test::KeyStr(/*ts=*/102, user_key[1], /*seq=*/2, kTypeValue)};
+  const std::vector<std::string> input_values = {"", "a3", "b2"};
+  std::string full_history_ts_low;
+  // All keys' timestamps are newer than or equal to 102, thus none of them
+  // will be eligible for GC.
+  PutFixed64(&full_history_ts_low, 102);
+  const std::vector<std::string>& expected_keys = input_keys;
+  const std::vector<std::string>& expected_values = input_values;
+  const std::vector<std::pair<bool, bool>> params = {
+      {false, false}, {false, true}, {true, true}};
+  for (const std::pair<bool, bool>& param : params) {
+    const bool bottommost_level = param.first;
+    const bool key_not_exists_beyond_output_level = param.second;
+    RunTest(input_keys, input_values, expected_keys, expected_values,
+            /*last_committed_seq=*/kMaxSequenceNumber,
+            /*merge_operator=*/nullptr, /*compaction_filter=*/nullptr,
+            bottommost_level,
+            /*earliest_write_conflict_snapshot=*/kMaxSequenceNumber,
+            key_not_exists_beyond_output_level, &full_history_ts_low);
+  }
+}
+
+TEST_P(CompactionIteratorTsGcTest, SingleDeleteDropTombstones) {
+  constexpr char user_key[] = "a";
+  const std::vector<std::string> input_keys = {
+      test::KeyStr(/*ts=*/103, user_key, /*seq=*/4, kTypeSingleDeletion),
+      test::KeyStr(/*ts=*/102, user_key, /*seq=*/3, kTypeValue),
+      test::KeyStr(/*ts=*/101, user_key, /*seq=*/2, kTypeSingleDeletion),
+      test::KeyStr(/*ts=*/100, user_key, /*seq=*/1, kTypeValue)};
+  const std::vector<std::string> input_values = {"", "a2", "", "a0"};
+  const std::vector<std::string> expected_keys = {input_keys[0], input_keys[1]};
+  const std::vector<std::string> expected_values = {"", "a2"};
+
+  // Take a snapshot at seq 2.
+  AddSnapshot(2);
+  {
+    const std::vector<std::pair<bool, bool>> params = {
+        {false, false}, {false, true}, {true, true}};
+    for (const std::pair<bool, bool>& param : params) {
+      const bool bottommost_level = param.first;
+      const bool key_not_exists_beyond_output_level = param.second;
+      std::string full_history_ts_low;
+      PutFixed64(&full_history_ts_low, 102);
+      RunTest(input_keys, input_values, expected_keys, expected_values,
+              /*last_committed_seq=*/kMaxSequenceNumber,
+              /*merge_operator=*/nullptr, /*compaction_filter=*/nullptr,
+              bottommost_level,
+              /*earliest_write_conflict_snapshot=*/kMaxSequenceNumber,
+              key_not_exists_beyond_output_level, &full_history_ts_low);
+    }
+  }
+}
+
+TEST_P(CompactionIteratorTsGcTest, SingleDeleteAllKeysOlderThanThreshold) {
+  constexpr char user_key[][2] = {{'a', '\0'}, {'b', '\0'}};
+  const std::vector<std::string> input_keys = {
+      test::KeyStr(/*ts=*/103, user_key[0], /*seq=*/4, kTypeSingleDeletion),
+      test::KeyStr(/*ts=*/102, user_key[0], /*seq=*/3, kTypeValue),
+      test::KeyStr(/*ts=*/104, user_key[1], /*seq=*/5, kTypeValue)};
+  const std::vector<std::string> input_values = {"", "a2", "b5"};
+  std::string full_history_ts_low;
+  PutFixed64(&full_history_ts_low, std::numeric_limits<uint64_t>::max());
+  {
+    // With a snapshot at seq 3, both the deletion marker and the key at 3 must
+    // be preserved.
+    AddSnapshot(3);
+    const std::vector<std::string> expected_keys = {
+        input_keys[0], input_keys[1], input_keys[2]};
+    const std::vector<std::string> expected_values = {"", "a2", "b5"};
+    RunTest(input_keys, input_values, expected_keys, expected_values,
+            /*last_committed_seq=*/kMaxSequenceNumber,
+            /*merge_operator=*/nullptr, /*compaction_filter=*/nullptr,
+            /*bottommost_level=*/false,
+            /*earliest_write_conflict_snapshot=*/kMaxSequenceNumber,
+            /*key_not_exists_beyond_output_level=*/false, &full_history_ts_low);
+    ClearSnapshots();
+  }
+  {
+    // No snapshot.
+    const std::vector<std::string> expected_keys = {input_keys[2]};
+    const std::vector<std::string> expected_values = {"b5"};
+    RunTest(input_keys, input_values, expected_keys, expected_values,
+            /*last_committed_seq=*/kMaxSequenceNumber,
+            /*merge_operator=*/nullptr, /*compaction_filter=*/nullptr,
+            /*bottommost_level=*/false,
+            /*earliest_write_conflict_snapshot=*/kMaxSequenceNumber,
+            /*key_not_exists_beyond_output_level=*/false, &full_history_ts_low);
+  }
+}
+
 INSTANTIATE_TEST_CASE_P(CompactionIteratorTsGcTestInstance,
                        CompactionIteratorTsGcTest,
                        testing::Values(true, false));
@@ -20,7 +20,6 @@
 #include "db/blob/blob_file_completion_callback.h"
 #include "db/column_family.h"
 #include "db/compaction/compaction_iterator.h"
-#include "db/dbformat.h"
 #include "db/flush_scheduler.h"
 #include "db/internal_stats.h"
 #include "db/job_context.h"
@@ -66,6 +65,7 @@ class CompactionJob {
 public:
  CompactionJob(
      int job_id, Compaction* compaction, const ImmutableDBOptions& db_options,
+      const MutableDBOptions& mutable_db_options,
      const FileOptions& file_options, VersionSet* versions,
      const std::atomic<bool>* shutting_down,
      const SequenceNumber preserve_deletes_seqnum, LogBuffer* log_buffer,
@@ -80,11 +80,12 @@ class CompactionJob {
      const std::string& dbname, CompactionJobStats* compaction_job_stats,
      Env::Priority thread_pri, const std::shared_ptr<IOTracer>& io_tracer,
      const std::atomic<int>* manual_compaction_paused = nullptr,
+      const std::atomic<bool>* manual_compaction_canceled = nullptr,
      const std::string& db_id = "", const std::string& db_session_id = "",
      std::string full_history_ts_low = "",
      BlobFileCompletionCallback* blob_callback = nullptr);

-  ~CompactionJob();
+  virtual ~CompactionJob();

  // no copy/move
  CompactionJob(CompactionJob&& job) = delete;
@@ -107,11 +108,36 @@ class CompactionJob {
  // Return the IO status
  IOStatus io_status() const { return io_status_; }

- private:
+ protected:
  struct SubcompactionState;
+  // CompactionJob state
+  struct CompactionState;

  void AggregateStatistics();
+  void UpdateCompactionStats();
+  void LogCompaction();
+  virtual void RecordCompactionIOStats();
+  void CleanupCompaction();

+  // Call compaction filter. Then iterate through input and compact the
+  // kv-pairs
+  void ProcessKeyValueCompaction(SubcompactionState* sub_compact);
+
+  CompactionState* compact_;
+  InternalStats::CompactionStats compaction_stats_;
+  const ImmutableDBOptions& db_options_;
+  const MutableDBOptions mutable_db_options_copy_;
+  LogBuffer* log_buffer_;
+  FSDirectory* output_directory_;
+  Statistics* stats_;
+  // Is this compaction creating a file in the bottom most level?
+  bool bottommost_level_;
+
+  Env::WriteLifeTimeHint write_hint_;
+
+  IOStatus io_status_;
+
+ private:
  // Generates a histogram representing potential divisions of key ranges from
  // the input. It adds the starting and/or ending keys of certain input files
  // to the working set and then finds the approximate size of data in between
@@ -119,12 +145,12 @@ class CompactionJob {
  // consecutive groups such that each group has a similar size.
  void GenSubcompactionBoundaries();

+  CompactionServiceJobStatus ProcessKeyValueCompactionWithCompactionService(
+      SubcompactionState* sub_compact);
+
  // update the thread status for starting a compaction.
  void ReportStartedCompaction(Compaction* compaction);
  void AllocateCompactionOutputFileNumbers();
-  // Call compaction filter. Then iterate through input and compact the
-  // kv-pairs
-  void ProcessKeyValueCompaction(SubcompactionState* sub_compact);

  Status FinishCompactionOutputFile(
      const Status& input_status, SubcompactionState* sub_compact,
@@ -132,33 +158,23 @@ class CompactionJob {
      CompactionIterationStats* range_del_out_stats,
      const Slice* next_table_min_key = nullptr);
  Status InstallCompactionResults(const MutableCFOptions& mutable_cf_options);
-  void RecordCompactionIOStats();
  Status OpenCompactionOutputFile(SubcompactionState* sub_compact);
-  void CleanupCompaction();
  void UpdateCompactionJobStats(
    const InternalStats::CompactionStats& stats) const;
  void RecordDroppedKeys(const CompactionIterationStats& c_iter_stats,
                         CompactionJobStats* compaction_job_stats = nullptr);

-  void UpdateCompactionStats();
  void UpdateCompactionInputStatsHelper(
      int* num_files, uint64_t* bytes_read, int input_level);

-  void LogCompaction();
+  uint32_t job_id_;

-  int job_id_;
-
-  // CompactionJob state
-  struct CompactionState;
-  CompactionState* compact_;
  CompactionJobStats* compaction_job_stats_;
-  InternalStats::CompactionStats compaction_stats_;

  // DBImpl state
  const std::string& dbname_;
  const std::string db_id_;
  const std::string db_session_id_;
-  const ImmutableDBOptions& db_options_;
  const FileOptions file_options_;

  Env* env_;
@@ -169,12 +185,10 @@ class CompactionJob {
  VersionSet* versions_;
  const std::atomic<bool>* shutting_down_;
  const std::atomic<int>* manual_compaction_paused_;
+  const std::atomic<bool>* manual_compaction_canceled_;
  const SequenceNumber preserve_deletes_seqnum_;
-  LogBuffer* log_buffer_;
  FSDirectory* db_directory_;
-  FSDirectory* output_directory_;
  FSDirectory* blob_output_directory_;
-  Statistics* stats_;
  InstrumentedMutex* db_mutex_;
  ErrorHandler* db_error_handler_;
  // If there were two snapshots with seq numbers s1 and
@@ -194,19 +208,158 @@ class CompactionJob {

  EventLogger* event_logger_;

-  // Is this compaction creating a file in the bottom most level?
-  bool bottommost_level_;
  bool paranoid_file_checks_;
  bool measure_io_stats_;
  // Stores the Slices that designate the boundaries for each subcompaction
  std::vector<Slice> boundaries_;
  // Stores the approx size of keys covered in the range of each subcompaction
  std::vector<uint64_t> sizes_;
-  Env::WriteLifeTimeHint write_hint_;
  Env::Priority thread_pri_;
-  IOStatus io_status_;
  std::string full_history_ts_low_;
  BlobFileCompletionCallback* blob_callback_;
+
+  uint64_t GetCompactionId(SubcompactionState* sub_compact);
+
+  // Get table file name in where it's outputting to, which should also be in
+  // `output_directory_`.
+  virtual std::string GetTableFileName(uint64_t file_number);
+};
+
+// CompactionServiceInput is used the pass compaction information between two
+// db instances. It contains the information needed to do a compaction. It
+// doesn't contain the LSM tree information, which is passed though MANIFEST
+// file.
+struct CompactionServiceInput {
+  ColumnFamilyDescriptor column_family;
+
+  DBOptions db_options;
+
+  std::vector<SequenceNumber> snapshots;
+
+  // SST files for compaction, it should already be expended to include all the
+  // files needed for this compaction, for both input level files and output
+  // level files.
+  std::vector<std::string> input_files;
+  int output_level;
+
+  // information for subcompaction
+  bool has_begin = false;
+  std::string begin;
+  bool has_end = false;
+  std::string end;
+  uint64_t approx_size = 0;
+
+  // serialization interface to read and write the object
+  static Status Read(const std::string& data_str, CompactionServiceInput* obj);
+  Status Write(std::string* output);
+
+  // Initialize a dummy ColumnFamilyDescriptor
+  CompactionServiceInput() : column_family("", ColumnFamilyOptions()) {}
+
+#ifndef NDEBUG
+  bool TEST_Equals(CompactionServiceInput* other);
+  bool TEST_Equals(CompactionServiceInput* other, std::string* mismatch);
+#endif  // NDEBUG
+};
+
+// CompactionServiceOutputFile is the metadata for the output SST file
+struct CompactionServiceOutputFile {
+  std::string file_name;
+  SequenceNumber smallest_seqno;
+  SequenceNumber largest_seqno;
+  std::string smallest_internal_key;
+  std::string largest_internal_key;
+  uint64_t oldest_ancester_time;
+  uint64_t file_creation_time;
+  uint64_t paranoid_hash;
+  bool marked_for_compaction;
+
+  CompactionServiceOutputFile() = default;
+  CompactionServiceOutputFile(
+      const std::string& name, SequenceNumber smallest, SequenceNumber largest,
+      std::string _smallest_internal_key, std::string _largest_internal_key,
+      uint64_t _oldest_ancester_time, uint64_t _file_creation_time,
+      uint64_t _paranoid_hash, bool _marked_for_compaction)
+      : file_name(name),
+        smallest_seqno(smallest),
+        largest_seqno(largest),
+        smallest_internal_key(std::move(_smallest_internal_key)),
+        largest_internal_key(std::move(_largest_internal_key)),
+        oldest_ancester_time(_oldest_ancester_time),
+        file_creation_time(_file_creation_time),
+        paranoid_hash(_paranoid_hash),
+        marked_for_compaction(_marked_for_compaction) {}
+};
+
+// CompactionServiceResult contains the compaction result from a different db
+// instance, with these information, the primary db instance with write
+// permission is able to install the result to the DB.
+struct CompactionServiceResult {
+  Status status;
+  std::vector<CompactionServiceOutputFile> output_files;
+  int output_level;
+
+  // location of the output files
+  std::string output_path;
+
+  // some statistics about the compaction
+  uint64_t num_output_records = 0;
+  uint64_t total_bytes = 0;
+  uint64_t bytes_read = 0;
+  uint64_t bytes_written = 0;
+  CompactionJobStats stats;
+
+  // serialization interface to read and write the object
+  static Status Read(const std::string& data_str, CompactionServiceResult* obj);
+  Status Write(std::string* output);
+
+#ifndef NDEBUG
+  bool TEST_Equals(CompactionServiceResult* other);
+  bool TEST_Equals(CompactionServiceResult* other, std::string* mismatch);
+#endif  // NDEBUG
+};
+
+// CompactionServiceCompactionJob is an read-only compaction job, it takes
+// input information from `compaction_service_input` and put result information
+// in `compaction_service_result`, the SST files are generated to `output_path`.
+class CompactionServiceCompactionJob : private CompactionJob {
+ public:
+  CompactionServiceCompactionJob(
+      int job_id, Compaction* compaction, const ImmutableDBOptions& db_options,
+      const MutableDBOptions& mutable_db_options,
+      const FileOptions& file_options, VersionSet* versions,
+      const std::atomic<bool>* shutting_down, LogBuffer* log_buffer,
+      FSDirectory* output_directory, Statistics* stats,
+      InstrumentedMutex* db_mutex, ErrorHandler* db_error_handler,
+      std::vector<SequenceNumber> existing_snapshots,
+      std::shared_ptr<Cache> table_cache, EventLogger* event_logger,
+      const std::string& dbname, const std::shared_ptr<IOTracer>& io_tracer,
+      const std::string& db_id, const std::string& db_session_id,
+      const std::string& output_path,
+      const CompactionServiceInput& compaction_service_input,
+      CompactionServiceResult* compaction_service_result);
+
+  // Run the compaction in current thread and return the result
+  Status Run();
+
+  void CleanupCompaction();
+
+  IOStatus io_status() const { return CompactionJob::io_status(); }
+
+ protected:
+  void RecordCompactionIOStats() override;
+
+ private:
+  // Get table file name in output_path
+  std::string GetTableFileName(uint64_t file_number) override;
+  // Specific the compaction output path, otherwise it uses default DB path
+  const std::string output_path_;
+
+  // Compaction job input
+  const CompactionServiceInput& compaction_input_;
+
+  // Compaction job result
+  CompactionServiceResult* compaction_result_;
 };

 }  // namespace ROCKSDB_NAMESPACE
@@ -24,7 +24,6 @@
 #include "db/write_batch_internal.h"
 #include "env/mock_env.h"
 #include "file/filename.h"
-#include "memtable/hash_linklist_rep.h"
 #include "monitoring/statistics.h"
 #include "monitoring/thread_status_util.h"
 #include "port/stack_trace.h"
@@ -269,10 +268,10 @@ class CompactionJobStatsTest : public testing::Test,
    if (cf == 0) {
      // default cfd
      EXPECT_TRUE(db_->GetProperty(
-          "rocksdb.num-files-at-level" + NumberToString(level), &property));
+          "rocksdb.num-files-at-level" + ToString(level), &property));
    } else {
      EXPECT_TRUE(db_->GetProperty(
-          handles_[cf], "rocksdb.num-files-at-level" + NumberToString(level),
+          handles_[cf], "rocksdb.num-files-at-level" + ToString(level),
          &property));
    }
    return atoi(property.c_str());
@@ -82,10 +82,11 @@ class CompactionJobTestBase : public testing::Test {
        mutable_db_options_(),
        table_cache_(NewLRUCache(50000, 16)),
        write_buffer_manager_(db_options_.db_write_buffer_size),
-        versions_(new VersionSet(
-            dbname_, &db_options_, env_options_, table_cache_.get(),
-            &write_buffer_manager_, &write_controller_,
-            /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr)),
+        versions_(new VersionSet(dbname_, &db_options_, env_options_,
+                                 table_cache_.get(), &write_buffer_manager_,
+                                 &write_controller_,
+                                 /*block_cache_tracer=*/nullptr,
+                                 /*io_tracer=*/nullptr, /*db_session_id*/ "")),
        shutting_down_(false),
        preserve_deletes_seqnum_(0),
        mock_table_factory_(new mock::MockTableFactory()),
@@ -269,7 +270,8 @@ class CompactionJobTestBase : public testing::Test {
    versions_.reset(
        new VersionSet(dbname_, &db_options_, env_options_, table_cache_.get(),
                       &write_buffer_manager_, &write_controller_,
-                       /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr));
+                       /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr,
+                       /*db_session_id*/ ""));
    compaction_job_stats_.Reset();
    ASSERT_OK(SetIdentityFile(env_, dbname_));

@@ -332,8 +334,8 @@ class CompactionJobTestBase : public testing::Test {
        cfd->current()->storage_info(), *cfd->ioptions(),
        *cfd->GetLatestMutableCFOptions(), mutable_db_options_,
        compaction_input_files, output_level, 1024 * 1024, 10 * 1024 * 1024, 0,
-        kNoCompression, cfd->GetLatestMutableCFOptions()->compression_opts, 0,
-        {}, true);
+        kNoCompression, cfd->GetLatestMutableCFOptions()->compression_opts,
+        Temperature::kUnknown, 0, {}, true);
    compaction.SetInputVersion(cfd->current());

    LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, db_options_.info_log.get());
@@ -344,13 +346,14 @@ class CompactionJobTestBase : public testing::Test {
    ASSERT_TRUE(full_history_ts_low_.empty() ||
                ucmp_->timestamp_size() == full_history_ts_low_.size());
    CompactionJob compaction_job(
-        0, &compaction, db_options_, env_options_, versions_.get(),
-        &shutting_down_, preserve_deletes_seqnum_, &log_buffer, nullptr,
-        nullptr, nullptr, nullptr, &mutex_, &error_handler_, snapshots,
+        0, &compaction, db_options_, mutable_db_options_, env_options_,
+        versions_.get(), &shutting_down_, preserve_deletes_seqnum_, &log_buffer,
+        nullptr, nullptr, nullptr, nullptr, &mutex_, &error_handler_, snapshots,
        earliest_write_conflict_snapshot, snapshot_checker, table_cache_,
        &event_logger, false, false, dbname_, &compaction_job_stats_,
        Env::Priority::USER, nullptr /* IOTracer */,
-        /*manual_compaction_paused=*/nullptr, /*db_id=*/"",
+        /*manual_compaction_paused=*/nullptr,
+        /*manual_compaction_canceled=*/nullptr, /*db_id=*/"",
        /*db_session_id=*/"", full_history_ts_low_);
    VerifyInitializationOfCompactionJobStats(compaction_job_stats_);

@@ -1096,6 +1099,187 @@ TEST_F(CompactionJobTest, OldestBlobFileNumber) {
                /* expected_oldest_blob_file_number */ 19);
 }

+TEST_F(CompactionJobTest, InputSerialization) {
+  // Setup a random CompactionServiceInput
+  CompactionServiceInput input;
+  const int kStrMaxLen = 1000;
+  Random rnd(static_cast<uint32_t>(time(nullptr)));
+  Random64 rnd64(time(nullptr));
+  input.column_family.name = rnd.RandomString(rnd.Uniform(kStrMaxLen));
+  input.column_family.options.comparator = ReverseBytewiseComparator();
+  input.column_family.options.max_bytes_for_level_base =
+      rnd64.Uniform(UINT64_MAX);
+  input.column_family.options.disable_auto_compactions = rnd.OneIn(2);
+  input.column_family.options.compression = kZSTD;
+  input.column_family.options.compression_opts.level = 4;
+  input.db_options.max_background_flushes = 10;
+  input.db_options.paranoid_checks = rnd.OneIn(2);
+  input.db_options.statistics = CreateDBStatistics();
+  input.db_options.env = env_;
+  while (!rnd.OneIn(10)) {
+    input.snapshots.emplace_back(rnd64.Uniform(UINT64_MAX));
+  }
+  while (!rnd.OneIn(10)) {
+    input.input_files.emplace_back(rnd.RandomString(
+        rnd.Uniform(kStrMaxLen - 1) +
+        1));  // input file name should have at least one character
+  }
+  input.output_level = 4;
+  input.has_begin = rnd.OneIn(2);
+  if (input.has_begin) {
+    input.begin = rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen));
+  }
+  input.has_end = rnd.OneIn(2);
+  if (input.has_end) {
+    input.end = rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen));
+  }
+  input.approx_size = rnd64.Uniform(UINT64_MAX);
+
+  std::string output;
+  ASSERT_OK(input.Write(&output));
+
+  // Test deserialization
+  CompactionServiceInput deserialized1;
+  ASSERT_OK(CompactionServiceInput::Read(output, &deserialized1));
+  ASSERT_TRUE(deserialized1.TEST_Equals(&input));
+
+  // Test mismatch
+  deserialized1.db_options.max_background_flushes += 10;
+  std::string mismatch;
+  ASSERT_FALSE(deserialized1.TEST_Equals(&input, &mismatch));
+  ASSERT_EQ(mismatch, "db_options.max_background_flushes");
+
+  // Test unknown field
+  CompactionServiceInput deserialized2;
+  output.clear();
+  ASSERT_OK(input.Write(&output));
+  output.append("new_field=123;");
+
+  ASSERT_OK(CompactionServiceInput::Read(output, &deserialized2));
+  ASSERT_TRUE(deserialized2.TEST_Equals(&input));
+
+  // Test missing field
+  CompactionServiceInput deserialized3;
+  deserialized3.output_level = 0;
+  std::string to_remove = "output_level=4;";
+  size_t pos = output.find(to_remove);
+  ASSERT_TRUE(pos != std::string::npos);
+  output.erase(pos, to_remove.length());
+  ASSERT_OK(CompactionServiceInput::Read(output, &deserialized3));
+  mismatch.clear();
+  ASSERT_FALSE(deserialized3.TEST_Equals(&input, &mismatch));
+  ASSERT_EQ(mismatch, "output_level");
+
+  // manually set the value back, should match the original structure
+  deserialized3.output_level = 4;
+  ASSERT_TRUE(deserialized3.TEST_Equals(&input));
+
+  // Test invalid version
+  output.clear();
+  ASSERT_OK(input.Write(&output));
+
+  uint32_t data_version = DecodeFixed32(output.data());
+  const size_t kDataVersionSize = sizeof(data_version);
+  ASSERT_EQ(data_version,
+            1U);  // Update once the default data version is changed
+  char buf[kDataVersionSize];
+  EncodeFixed32(buf, data_version + 10);  // make sure it's not valid
+  output.replace(0, kDataVersionSize, buf, kDataVersionSize);
+  Status s = CompactionServiceInput::Read(output, &deserialized3);
+  ASSERT_TRUE(s.IsNotSupported());
+}
+
+TEST_F(CompactionJobTest, ResultSerialization) {
+  // Setup a random CompactionServiceResult
+  CompactionServiceResult result;
+  const int kStrMaxLen = 1000;
+  Random rnd(static_cast<uint32_t>(time(nullptr)));
+  Random64 rnd64(time(nullptr));
+  std::vector<Status> status_list = {
+      Status::OK(),
+      Status::InvalidArgument("invalid option"),
+      Status::Aborted("failed to run"),
+      Status::NotSupported("not supported option"),
+  };
+  result.status =
+      status_list.at(rnd.Uniform(static_cast<int>(status_list.size())));
+  while (!rnd.OneIn(10)) {
+    result.output_files.emplace_back(
+        rnd.RandomString(rnd.Uniform(kStrMaxLen)), rnd64.Uniform(UINT64_MAX),
+        rnd64.Uniform(UINT64_MAX),
+        rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen)),
+        rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen)),
+        rnd64.Uniform(UINT64_MAX), rnd64.Uniform(UINT64_MAX),
+        rnd64.Uniform(UINT64_MAX), rnd.OneIn(2));
+  }
+  result.output_level = rnd.Uniform(10);
+  result.output_path = rnd.RandomString(rnd.Uniform(kStrMaxLen));
+  result.num_output_records = rnd64.Uniform(UINT64_MAX);
+  result.total_bytes = rnd64.Uniform(UINT64_MAX);
+  result.bytes_read = 123;
+  result.bytes_written = rnd64.Uniform(UINT64_MAX);
+  result.stats.elapsed_micros = rnd64.Uniform(UINT64_MAX);
+  result.stats.num_output_files = rnd.Uniform(1000);
+  result.stats.is_full_compaction = rnd.OneIn(2);
+  result.stats.num_single_del_mismatch = rnd64.Uniform(UINT64_MAX);
+  result.stats.num_input_files = 9;
+
+  std::string output;
+  ASSERT_OK(result.Write(&output));
+
+  // Test deserialization
+  CompactionServiceResult deserialized1;
+  ASSERT_OK(CompactionServiceResult::Read(output, &deserialized1));
+  ASSERT_TRUE(deserialized1.TEST_Equals(&result));
+
+  // Test mismatch
+  deserialized1.stats.num_input_files += 10;
+  std::string mismatch;
+  ASSERT_FALSE(deserialized1.TEST_Equals(&result, &mismatch));
+  ASSERT_EQ(mismatch, "stats.num_input_files");
+
+  // Test unknown field
+  CompactionServiceResult deserialized2;
+  output.clear();
+  ASSERT_OK(result.Write(&output));
+  output.append("new_field=123;");
+
+  ASSERT_OK(CompactionServiceResult::Read(output, &deserialized2));
+  ASSERT_TRUE(deserialized2.TEST_Equals(&result));
+
+  // Test missing field
+  CompactionServiceResult deserialized3;
+  deserialized3.bytes_read = 0;
+  std::string to_remove = "bytes_read=123;";
+  size_t pos = output.find(to_remove);
+  ASSERT_TRUE(pos != std::string::npos);
+  output.erase(pos, to_remove.length());
+  ASSERT_OK(CompactionServiceResult::Read(output, &deserialized3));
+  mismatch.clear();
+  ASSERT_FALSE(deserialized3.TEST_Equals(&result, &mismatch));
+  ASSERT_EQ(mismatch, "bytes_read");
+
+  deserialized3.bytes_read = 123;
+  ASSERT_TRUE(deserialized3.TEST_Equals(&result));
+
+  // Test invalid version
+  output.clear();
+  ASSERT_OK(result.Write(&output));
+
+  uint32_t data_version = DecodeFixed32(output.data());
+  const size_t kDataVersionSize = sizeof(data_version);
+  ASSERT_EQ(data_version,
+            1U);  // Update once the default data version is changed
+  char buf[kDataVersionSize];
+  EncodeFixed32(buf, data_version + 10);  // make sure it's not valid
+  output.replace(0, kDataVersionSize, buf, kDataVersionSize);
+  Status s = CompactionServiceResult::Read(output, &deserialized3);
+  ASSERT_TRUE(s.IsNotSupported());
+  for (const auto& item : status_list) {
+    item.PermitUncheckedError();
+  }
+}
+
 class CompactionJobTimestampTest : public CompactionJobTestBase {
 public:
  CompactionJobTimestampTest()
@@ -1109,13 +1293,16 @@ TEST_F(CompactionJobTimestampTest, GCDisabled) {
  auto file1 =
      mock::MakeMockFile({{KeyStr("a", 10, ValueType::kTypeValue, 100), "a10"},
                          {KeyStr("a", 9, ValueType::kTypeValue, 99), "a9"},
-                          {KeyStr("b", 8, ValueType::kTypeValue, 98), "b8"}});
+                          {KeyStr("b", 8, ValueType::kTypeValue, 98), "b8"},
+                          {KeyStr("d", 7, ValueType::kTypeValue, 97), "d7"}});
+
  AddMockFile(file1);

  auto file2 = mock::MakeMockFile(
-      {{KeyStr("b", 7, ValueType::kTypeDeletionWithTimestamp, 97), ""},
-       {KeyStr("c", 6, ValueType::kTypeDeletionWithTimestamp, 96), ""},
-       {KeyStr("c", 5, ValueType::kTypeValue, 95), "c5"}});
+      {{KeyStr("b", 6, ValueType::kTypeDeletionWithTimestamp, 96), ""},
+       {KeyStr("c", 5, ValueType::kTypeDeletionWithTimestamp, 95), ""},
+       {KeyStr("c", 4, ValueType::kTypeValue, 94), "c5"},
+       {KeyStr("d", 3, ValueType::kTypeSingleDeletion, 93), ""}});
  AddMockFile(file2);

  SetLastSequence(10);
@@ -1124,9 +1311,11 @@ TEST_F(CompactionJobTimestampTest, GCDisabled) {
      {{KeyStr("a", 10, ValueType::kTypeValue, 100), "a10"},
       {KeyStr("a", 9, ValueType::kTypeValue, 99), "a9"},
       {KeyStr("b", 8, ValueType::kTypeValue, 98), "b8"},
-       {KeyStr("b", 7, ValueType::kTypeDeletionWithTimestamp, 97), ""},
-       {KeyStr("c", 6, ValueType::kTypeDeletionWithTimestamp, 96), ""},
-       {KeyStr("c", 5, ValueType::kTypeValue, 95), "c5"}});
+       {KeyStr("b", 6, ValueType::kTypeDeletionWithTimestamp, 96), ""},
+       {KeyStr("c", 5, ValueType::kTypeDeletionWithTimestamp, 95), ""},
+       {KeyStr("c", 4, ValueType::kTypeValue, 94), "c5"},
+       {KeyStr("d", 7, ValueType::kTypeValue, 97), "d7"},
+       {KeyStr("d", 3, ValueType::kTypeSingleDeletion, 93), ""}});
  const auto& files = cfd_->current()->storage_info()->LevelFiles(0);
  RunCompaction({files}, expected_results);
 }
@@ -1164,19 +1353,21 @@ TEST_F(CompactionJobTimestampTest, AllKeysExpired) {

  auto file1 = mock::MakeMockFile(
      {{KeyStr("a", 5, ValueType::kTypeDeletionWithTimestamp, 100), ""},
-       {KeyStr("b", 6, ValueType::kTypeValue, 99), "b6"}});
+       {KeyStr("b", 6, ValueType::kTypeSingleDeletion, 99), ""},
+       {KeyStr("c", 7, ValueType::kTypeValue, 98), "c7"}});
  AddMockFile(file1);

  auto file2 = mock::MakeMockFile(
-      {{KeyStr("a", 4, ValueType::kTypeValue, 98), "a4"},
-       {KeyStr("b", 3, ValueType::kTypeDeletionWithTimestamp, 97), ""},
-       {KeyStr("b", 2, ValueType::kTypeValue, 96), "b2"}});
+      {{KeyStr("a", 4, ValueType::kTypeValue, 97), "a4"},
+       {KeyStr("b", 3, ValueType::kTypeValue, 96), "b3"},
+       {KeyStr("c", 2, ValueType::kTypeDeletionWithTimestamp, 95), ""},
+       {KeyStr("c", 1, ValueType::kTypeValue, 94), "c1"}});
  AddMockFile(file2);

-  SetLastSequence(6);
+  SetLastSequence(7);

  auto expected_results =
-      mock::MakeMockFile({{KeyStr("b", 0, ValueType::kTypeValue, 0), "b6"}});
+      mock::MakeMockFile({{KeyStr("c", 0, ValueType::kTypeValue, 0), "c7"}});
  const auto& files = cfd_->current()->storage_info()->LevelFiles(0);

  full_history_ts_low_ = encode_u64_ts_(std::numeric_limits<uint64_t>::max());
@@ -15,9 +15,11 @@
 #include <string>
 #include <utility>
 #include <vector>
+
 #include "db/column_family.h"
 #include "file/filename.h"
 #include "logging/log_buffer.h"
+#include "logging/logging.h"
 #include "monitoring/statistics.h"
 #include "test_util/sync_point.h"
 #include "util/random.h"
@@ -148,7 +150,7 @@ CompressionOptions GetCompressionOptions(const MutableCFOptions& cf_options,
  return cf_options.compression_opts;
 }

-CompactionPicker::CompactionPicker(const ImmutableCFOptions& ioptions,
+CompactionPicker::CompactionPicker(const ImmutableOptions& ioptions,
                                   const InternalKeyComparator* icmp)
    : ioptions_(ioptions), icmp_(icmp) {}

@@ -358,7 +360,7 @@ Compaction* CompactionPicker::CompactFiles(
      output_level, compact_options.output_file_size_limit,
      mutable_cf_options.max_compaction_bytes, output_path_id, compression_type,
      GetCompressionOptions(mutable_cf_options, vstorage, output_level),
-      compact_options.max_subcompactions,
+      Temperature::kUnknown, compact_options.max_subcompactions,
      /* grandparents */ {}, true);
  RegisterCompaction(c);
  return c;
@@ -530,7 +532,7 @@ bool CompactionPicker::SetupOtherInputs(
      }
    }
    if (expand_inputs) {
-      ROCKS_LOG_INFO(ioptions_.info_log,
+      ROCKS_LOG_INFO(ioptions_.logger,
                     "[%s] Expanding@%d %" ROCKSDB_PRIszt "+%" ROCKSDB_PRIszt
                     "(%" PRIu64 "+%" PRIu64 " bytes) to %" ROCKSDB_PRIszt
                     "+%" ROCKSDB_PRIszt " (%" PRIu64 "+%" PRIu64 " bytes)\n",
@@ -552,10 +554,14 @@ void CompactionPicker::GetGrandparents(
  InternalKey start, limit;
  GetRange(inputs, output_level_inputs, &start, &limit);
  // Compute the set of grandparent files that overlap this compaction
-  // (parent == level+1; grandparent == level+2)
-  if (output_level_inputs.level + 1 < NumberLevels()) {
-    vstorage->GetOverlappingInputs(output_level_inputs.level + 1, &start,
-                                   &limit, grandparents);
+  // (parent == level+1; grandparent == level+2 or the first
+  // level after that has overlapping files)
+  for (int level = output_level_inputs.level + 1; level < NumberLevels();
+       level++) {
+    vstorage->GetOverlappingInputs(level, &start, &limit, grandparents);
+    if (!grandparents->empty()) {
+      break;
+    }
  }
 }

@@ -634,7 +640,8 @@ Compaction* CompactionPicker::CompactRange(
        GetCompressionType(ioptions_, vstorage, mutable_cf_options,
                           output_level, 1),
        GetCompressionOptions(mutable_cf_options, vstorage, output_level),
-        compact_range_options.max_subcompactions, /* grandparents */ {},
+        Temperature::kUnknown, compact_range_options.max_subcompactions,
+        /* grandparents */ {},
        /* is manual */ true);
    RegisterCompaction(c);
    vstorage->ComputeCompactionScore(ioptions_, mutable_cf_options);
@@ -670,17 +677,41 @@ Compaction* CompactionPicker::CompactRange(
  // two files overlap.
  if (input_level > 0) {
    const uint64_t limit = mutable_cf_options.max_compaction_bytes;
-    uint64_t total = 0;
+    uint64_t input_level_total = 0;
+    int hint_index = -1;
+    InternalKey* smallest = nullptr;
+    InternalKey* largest = nullptr;
    for (size_t i = 0; i + 1 < inputs.size(); ++i) {
+      if (!smallest) {
+        smallest = &inputs[i]->smallest;
+      }
+      largest = &inputs[i]->largest;
+
      uint64_t s = inputs[i]->compensated_file_size;
-      total += s;
-      if (total >= limit) {
+      uint64_t output_level_total = 0;
+      if (output_level < vstorage->num_non_empty_levels()) {
+        std::vector<FileMetaData*> files;
+        vstorage->GetOverlappingInputsRangeBinarySearch(
+            output_level, smallest, largest, &files, hint_index, &hint_index);
+        for (const auto& file : files) {
+          output_level_total += file->compensated_file_size;
+        }
+      }
+
+      input_level_total += s;
+
+      if (input_level_total + output_level_total >= limit) {
        covering_the_whole_range = false;
+        // still include the current file, so the compaction could be larger
+        // than max_compaction_bytes, which is also to make sure the compaction
+        // can make progress even `max_compaction_bytes` is small (e.g. smaller
+        // than an SST file).
        inputs.files.resize(i + 1);
        break;
      }
    }
  }
+
  assert(compact_range_options.target_path_id <
         static_cast<uint32_t>(ioptions_.cf_paths.size()));

@@ -788,7 +819,8 @@ Compaction* CompactionPicker::CompactRange(
      GetCompressionType(ioptions_, vstorage, mutable_cf_options, output_level,
                         vstorage->base_level()),
      GetCompressionOptions(mutable_cf_options, vstorage, output_level),
-      compact_range_options.max_subcompactions, std::move(grandparents),
+      Temperature::kUnknown, compact_range_options.max_subcompactions,
+      std::move(grandparents),
      /* is manual compaction */ true);

  TEST_SYNC_POINT_CALLBACK("CompactionPicker::CompactRange:Return", compaction);
@@ -46,7 +46,7 @@ struct CompactionInputFiles;
 // compaction style specific logic for them.
 class CompactionPicker {
 public:
-  CompactionPicker(const ImmutableCFOptions& ioptions,
+  CompactionPicker(const ImmutableOptions& ioptions,
                   const InternalKeyComparator* icmp);
  virtual ~CompactionPicker();

@@ -218,7 +218,7 @@ class CompactionPicker {
  }

 protected:
-  const ImmutableCFOptions& ioptions_;
+  const ImmutableOptions& ioptions_;

 // A helper function to SanitizeCompactionInputFiles() that
 // sanitizes "input_files" by adding necessary files.
@@ -244,7 +244,7 @@ class CompactionPicker {
 // compaction.
 class NullCompactionPicker : public CompactionPicker {
 public:
-  NullCompactionPicker(const ImmutableCFOptions& ioptions,
+  NullCompactionPicker(const ImmutableOptions& ioptions,
                       const InternalKeyComparator* icmp)
      : CompactionPicker(ioptions, icmp) {}
  virtual ~NullCompactionPicker() {}
@@ -13,8 +13,10 @@
 #include <cinttypes>
 #include <string>
 #include <vector>
+
 #include "db/column_family.h"
 #include "logging/log_buffer.h"
+#include "logging/logging.h"
 #include "util/string_util.h"

 namespace ROCKSDB_NAMESPACE {
@@ -111,7 +113,7 @@ Compaction* FIFOCompactionPicker::PickTTLCompaction(
  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, mutable_db_options,
      std::move(inputs), 0, 0, 0, 0, kNoCompression,
-      mutable_cf_options.compression_opts,
+      mutable_cf_options.compression_opts, Temperature::kUnknown,
      /* max_subcompactions */ 0, {}, /* is manual */ false,
      vstorage->CompactionScore(0),
      /* is deletion compaction */ true, CompactionReason::kFIFOTtl);
@@ -154,7 +156,8 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(
            {comp_inputs}, 0, 16 * 1024 * 1024 /* output file size limit */,
            0 /* max compaction bytes, not applicable */,
            0 /* output path ID */, mutable_cf_options.compression,
-            mutable_cf_options.compression_opts, 0 /* max_subcompactions */, {},
+            mutable_cf_options.compression_opts, Temperature::kUnknown,
+            0 /* max_subcompactions */, {},
            /* is manual */ false, vstorage->CompactionScore(0),
            /* is deletion compaction */ false,
            CompactionReason::kFIFOReduceNumFiles);
@@ -203,13 +206,119 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(
  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, mutable_db_options,
      std::move(inputs), 0, 0, 0, 0, kNoCompression,
-      mutable_cf_options.compression_opts,
+      mutable_cf_options.compression_opts, Temperature::kUnknown,
      /* max_subcompactions */ 0, {}, /* is manual */ false,
      vstorage->CompactionScore(0),
      /* is deletion compaction */ true, CompactionReason::kFIFOMaxSize);
  return c;
 }

+Compaction* FIFOCompactionPicker::PickCompactionToWarm(
+    const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
+    const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
+    LogBuffer* log_buffer) {
+  if (mutable_cf_options.compaction_options_fifo.age_for_warm == 0) {
+    return nullptr;
+  }
+
+  const int kLevel0 = 0;
+  const std::vector<FileMetaData*>& level_files = vstorage->LevelFiles(kLevel0);
+
+  int64_t _current_time;
+  auto status = ioptions_.clock->GetCurrentTime(&_current_time);
+  if (!status.ok()) {
+    ROCKS_LOG_BUFFER(log_buffer,
+                     "[%s] FIFO compaction: Couldn't get current time: %s. "
+                     "Not doing compactions based on warm threshold. ",
+                     cf_name.c_str(), status.ToString().c_str());
+    return nullptr;
+  }
+  const uint64_t current_time = static_cast<uint64_t>(_current_time);
+
+  if (!level0_compactions_in_progress_.empty()) {
+    ROCKS_LOG_BUFFER(
+        log_buffer,
+        "[%s] FIFO compaction: Already executing compaction. Parallel "
+        "compactions are not supported",
+        cf_name.c_str());
+    return nullptr;
+  }
+
+  std::vector<CompactionInputFiles> inputs;
+  inputs.emplace_back();
+  inputs[0].level = 0;
+
+  // avoid underflow
+  if (current_time > mutable_cf_options.compaction_options_fifo.age_for_warm) {
+    uint64_t create_time_threshold =
+        current_time - mutable_cf_options.compaction_options_fifo.age_for_warm;
+    uint64_t compaction_size = 0;
+    // We will ideally identify a file qualifying for warm tier by knowing
+    // the timestamp for the youngest entry in the file. However, right now
+    // we don't have the information. We infer it by looking at timestamp
+    // of the next file's (which is just younger) oldest entry's timestamp.
+    FileMetaData* prev_file = nullptr;
+    for (auto ritr = level_files.rbegin(); ritr != level_files.rend(); ++ritr) {
+      FileMetaData* f = *ritr;
+      assert(f);
+      if (f->being_compacted) {
+        // Right now this probably won't happen as we never try to schedule
+        // two compactions in parallel, so here we just simply don't schedule
+        // anything.
+        return nullptr;
+      }
+      uint64_t oldest_ancester_time = f->TryGetOldestAncesterTime();
+      if (oldest_ancester_time == kUnknownOldestAncesterTime) {
+        // Older files might not have enough information. It is possible to
+        // handle these files by looking at newer files, but maintaining the
+        // logic isn't worth it.
+        break;
+      }
+      if (oldest_ancester_time > create_time_threshold) {
+        // The previous file (which has slightly older data) doesn't qualify
+        // for warm tier.
+        break;
+      }
+      if (prev_file != nullptr) {
+        compaction_size += prev_file->fd.GetFileSize();
+        if (compaction_size > mutable_cf_options.max_compaction_bytes) {
+          break;
+        }
+        inputs[0].files.push_back(prev_file);
+        ROCKS_LOG_BUFFER(log_buffer,
+                         "[%s] FIFO compaction: picking file %" PRIu64
+                         " with next file's oldest time %" PRIu64 " for warm",
+                         cf_name.c_str(), prev_file->fd.GetNumber(),
+                         oldest_ancester_time);
+      }
+      if (f->temperature == Temperature::kUnknown ||
+          f->temperature == Temperature::kHot) {
+        prev_file = f;
+      } else if (!inputs[0].files.empty()) {
+        // A warm file newer than files picked.
+        break;
+      } else {
+        assert(prev_file == nullptr);
+      }
+    }
+  }
+
+  if (inputs[0].files.empty()) {
+    return nullptr;
+  }
+
+  Compaction* c = new Compaction(
+      vstorage, ioptions_, mutable_cf_options, mutable_db_options,
+      std::move(inputs), 0, 0 /* output file size limit */,
+      0 /* max compaction bytes, not applicable */, 0 /* output path ID */,
+      mutable_cf_options.compression, mutable_cf_options.compression_opts,
+      Temperature::kWarm,
+      /* max_subcompactions */ 0, {}, /* is manual */ false,
+      vstorage->CompactionScore(0),
+      /* is deletion compaction */ false, CompactionReason::kChangeTemperature);
+  return c;
+}
+
 Compaction* FIFOCompactionPicker::PickCompaction(
    const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
    const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
@@ -225,6 +334,10 @@ Compaction* FIFOCompactionPicker::PickCompaction(
    c = PickSizeCompaction(cf_name, mutable_cf_options, mutable_db_options,
                           vstorage, log_buffer);
  }
+  if (c == nullptr) {
+    c = PickCompactionToWarm(cf_name, mutable_cf_options, mutable_db_options,
+                             vstorage, log_buffer);
+  }
  RegisterCompaction(c);
  return c;
 }
@@ -244,7 +357,7 @@ Compaction* FIFOCompactionPicker::CompactRange(
  assert(input_level == 0);
  assert(output_level == 0);
  *compaction_end = nullptr;
-  LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, ioptions_.info_log);
+  LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, ioptions_.logger);
  Compaction* c = PickCompaction(cf_name, mutable_cf_options,
                                 mutable_db_options, vstorage, &log_buffer);
  log_buffer.FlushBufferToLog();
@@ -15,7 +15,7 @@
 namespace ROCKSDB_NAMESPACE {
 class FIFOCompactionPicker : public CompactionPicker {
 public:
-  FIFOCompactionPicker(const ImmutableCFOptions& ioptions,
+  FIFOCompactionPicker(const ImmutableOptions& ioptions,
                       const InternalKeyComparator* icmp)
      : CompactionPicker(ioptions, icmp) {}

@@ -52,6 +52,12 @@ class FIFOCompactionPicker : public CompactionPicker {
                                 const MutableDBOptions& mutable_db_options,
                                 VersionStorageInfo* version,
                                 LogBuffer* log_buffer);
+
+  Compaction* PickCompactionToWarm(const std::string& cf_name,
+                                   const MutableCFOptions& mutable_cf_options,
+                                   const MutableDBOptions& mutable_db_options,
+                                   VersionStorageInfo* version,
+                                   LogBuffer* log_buffer);
 };
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // !ROCKSDB_LITE
@@ -31,6 +31,9 @@ bool LevelCompactionPicker::NeedsCompaction(
  if (!vstorage->FilesMarkedForCompaction().empty()) {
    return true;
  }
+  if (!vstorage->FilesMarkedForForcedBlobGC().empty()) {
+    return true;
+  }
  for (int i = 0; i <= vstorage->MaxInputLevel(); i++) {
    if (vstorage->CompactionScore(i) >= 1) {
      return true;
@@ -49,7 +52,7 @@ class LevelCompactionBuilder {
                         CompactionPicker* compaction_picker,
                         LogBuffer* log_buffer,
                         const MutableCFOptions& mutable_cf_options,
-                         const ImmutableCFOptions& ioptions,
+                         const ImmutableOptions& ioptions,
                         const MutableDBOptions& mutable_db_options)
      : cf_name_(cf_name),
        vstorage_(vstorage),
@@ -121,7 +124,7 @@ class LevelCompactionBuilder {
  CompactionReason compaction_reason_ = CompactionReason::kUnknown;

  const MutableCFOptions& mutable_cf_options_;
-  const ImmutableCFOptions& ioptions_;
+  const ImmutableOptions& ioptions_;
  const MutableDBOptions& mutable_db_options_;
  // Pick a path ID to place a newly generated file, with its level
  static uint32_t GetPathId(const ImmutableCFOptions& ioptions,
@@ -248,6 +251,13 @@ void LevelCompactionBuilder::SetupInitialFiles() {
    compaction_reason_ = CompactionReason::kPeriodicCompaction;
    return;
  }
+
+  // Forced blob garbage collection
+  PickFileToCompact(vstorage_->FilesMarkedForForcedBlobGC(), false);
+  if (!start_level_inputs_.empty()) {
+    compaction_reason_ = CompactionReason::kForcedBlobGC;
+    return;
+  }
 }

 bool LevelCompactionBuilder::SetupOtherL0FilesIfNeeded() {
@@ -336,6 +346,7 @@ Compaction* LevelCompactionBuilder::GetCompaction() {
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
                         output_level_, vstorage_->base_level()),
      GetCompressionOptions(mutable_cf_options_, vstorage_, output_level_),
+      Temperature::kUnknown,
      /* max_subcompactions */ 0, std::move(grandparents_), is_manual_,
      start_level_score_, false /* deletion_compaction */, compaction_reason_);

@@ -384,7 +395,7 @@ uint32_t LevelCompactionBuilder::GetPathId(
          if (ioptions.level_compaction_dynamic_level_bytes) {
            // Currently, level_compaction_dynamic_level_bytes is ignored when
            // multiple db paths are specified. https://github.com/facebook/
-            // rocksdb/blob/master/db/column_family.cc.
+            // rocksdb/blob/main/db/column_family.cc.
            // Still, adding this check to avoid accidentally using
            // max_bytes_for_level_multiplier_additional
            level_size = static_cast<uint64_t>(
@@ -17,7 +17,7 @@ namespace ROCKSDB_NAMESPACE {
 // for description of Leveled compaction.
 class LevelCompactionPicker : public CompactionPicker {
 public:
-  LevelCompactionPicker(const ImmutableCFOptions& ioptions,
+  LevelCompactionPicker(const ImmutableOptions& ioptions,
                        const InternalKeyComparator* icmp)
      : CompactionPicker(ioptions, icmp) {}
  virtual Compaction* PickCompaction(
@@ -30,7 +30,7 @@ class CompactionPickerTest : public testing::Test {
  const Comparator* ucmp_;
  InternalKeyComparator icmp_;
  Options options_;
-  ImmutableCFOptions ioptions_;
+  ImmutableOptions ioptions_;
  MutableCFOptions mutable_cf_options_;
  MutableDBOptions mutable_db_options_;
  LevelCompactionPicker level_compaction_picker;
@@ -98,7 +98,9 @@ class CompactionPickerTest : public testing::Test {
  void Add(int level, uint32_t file_number, const char* smallest,
           const char* largest, uint64_t file_size = 1, uint32_t path_id = 0,
           SequenceNumber smallest_seq = 100, SequenceNumber largest_seq = 100,
-           size_t compensated_file_size = 0, bool marked_for_compact = false) {
+           size_t compensated_file_size = 0, bool marked_for_compact = false,
+           Temperature temperature = Temperature::kUnknown,
+           uint64_t oldest_ancestor_time = kUnknownOldestAncesterTime) {
    VersionStorageInfo* vstorage;
    if (temp_vstorage_) {
      vstorage = temp_vstorage_.get();
@@ -115,6 +117,8 @@ class CompactionPickerTest : public testing::Test {
        kUnknownFileChecksum, kUnknownFileChecksumFuncName);
    f->compensated_file_size =
        (compensated_file_size != 0) ? compensated_file_size : file_size;
+    f->temperature = temperature;
+    f->oldest_ancester_time = oldest_ancestor_time;
    vstorage->AddFile(level, f);
    files_.emplace_back(f);
    file_map_.insert({file_number, {f, level}});
@@ -729,6 +733,221 @@ TEST_F(CompactionPickerTest, UniversalPeriodicCompaction6) {
  ASSERT_EQ(4, compaction->output_level());
 }

+TEST_F(CompactionPickerTest, UniversalIncrementalSpace1) {
+  const uint64_t kFileSize = 100000;
+
+  mutable_cf_options_.max_compaction_bytes = 555555;
+  mutable_cf_options_.compaction_options_universal.incremental = true;
+  mutable_cf_options_.compaction_options_universal
+      .max_size_amplification_percent = 30;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(2, 2U, "010", "080", kFileSize, 0, 200, 251);
+  Add(3, 5U, "310", "380", kFileSize, 0, 200, 251);
+  Add(3, 6U, "410", "880", kFileSize, 0, 200, 251);
+  Add(3, 7U, "910", "980", 1, 0, 200, 251);
+  Add(4, 10U, "201", "250", kFileSize, 0, 101, 150);
+  Add(4, 11U, "301", "350", kFileSize, 0, 101, 150);
+  Add(4, 12U, "401", "450", kFileSize, 0, 101, 150);
+  Add(4, 13U, "501", "750", kFileSize, 0, 101, 150);
+  Add(4, 14U, "801", "850", kFileSize, 0, 101, 150);
+  Add(4, 15U, "901", "950", kFileSize, 0, 101, 150);
+  //  Add(4, 15U, "960", "970", kFileSize, 0, 101, 150);
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+          &log_buffer_));
+  ASSERT_TRUE(compaction);
+  ASSERT_EQ(4, compaction->output_level());
+  ASSERT_EQ(3, compaction->start_level());
+  ASSERT_EQ(2U, compaction->num_input_files(0));
+  ASSERT_EQ(5U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(6U, compaction->input(0, 1)->fd.GetNumber());
+  // ASSERT_EQ(4U, compaction->num_input_files(1));
+  ASSERT_EQ(11U, compaction->input(1, 0)->fd.GetNumber());
+  ASSERT_EQ(12U, compaction->input(1, 1)->fd.GetNumber());
+  ASSERT_EQ(13U, compaction->input(1, 2)->fd.GetNumber());
+  ASSERT_EQ(14U, compaction->input(1, 3)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, UniversalIncrementalSpace2) {
+  const uint64_t kFileSize = 100000;
+
+  mutable_cf_options_.max_compaction_bytes = 400000;
+  mutable_cf_options_.compaction_options_universal.incremental = true;
+  mutable_cf_options_.compaction_options_universal
+      .max_size_amplification_percent = 30;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(1, 2U, "010", "080", kFileSize, 0, 200, 251);
+  Add(2, 5U, "310", "380", kFileSize, 0, 200, 251);
+  Add(2, 6U, "410", "880", kFileSize, 0, 200, 251);
+  Add(2, 7U, "910", "980", kFileSize, 0, 200, 251);
+  Add(4, 10U, "201", "250", kFileSize, 0, 101, 150);
+  Add(4, 11U, "301", "350", kFileSize, 0, 101, 150);
+  Add(4, 12U, "401", "450", kFileSize, 0, 101, 150);
+  Add(4, 13U, "501", "750", kFileSize, 0, 101, 150);
+  Add(4, 14U, "801", "850", kFileSize, 0, 101, 150);
+  Add(4, 15U, "901", "950", kFileSize, 0, 101, 150);
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+          &log_buffer_));
+  ASSERT_TRUE(compaction);
+  ASSERT_EQ(4, compaction->output_level());
+  ASSERT_EQ(2, compaction->start_level());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(7U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(1U, compaction->num_input_files(1));
+  ASSERT_EQ(15U, compaction->input(1, 0)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, UniversalIncrementalSpace3) {
+  // Test bottom level files falling between gaps between two upper level
+  // files
+  const uint64_t kFileSize = 100000;
+
+  mutable_cf_options_.max_compaction_bytes = 300000;
+  mutable_cf_options_.compaction_options_universal.incremental = true;
+  mutable_cf_options_.compaction_options_universal
+      .max_size_amplification_percent = 30;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(2, 2U, "010", "080", kFileSize, 0, 200, 251);
+  Add(3, 5U, "000", "180", kFileSize, 0, 200, 251);
+  Add(3, 6U, "181", "190", kFileSize, 0, 200, 251);
+  Add(3, 7U, "710", "810", kFileSize, 0, 200, 251);
+  Add(3, 8U, "820", "830", kFileSize, 0, 200, 251);
+  Add(3, 9U, "900", "991", kFileSize, 0, 200, 251);
+  Add(4, 10U, "201", "250", kFileSize, 0, 101, 150);
+  Add(4, 11U, "301", "350", kFileSize, 0, 101, 150);
+  Add(4, 12U, "401", "450", kFileSize, 0, 101, 150);
+  Add(4, 13U, "501", "750", kFileSize, 0, 101, 150);
+  Add(4, 14U, "801", "850", kFileSize, 0, 101, 150);
+  Add(4, 15U, "901", "950", kFileSize, 0, 101, 150);
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+          &log_buffer_));
+  ASSERT_TRUE(compaction);
+  ASSERT_EQ(4, compaction->output_level());
+  ASSERT_EQ(2, compaction->start_level());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(2U, compaction->num_input_files(1));
+  ASSERT_EQ(5U, compaction->input(1, 0)->fd.GetNumber());
+  ASSERT_EQ(6U, compaction->input(1, 1)->fd.GetNumber());
+  ASSERT_EQ(0, compaction->num_input_files(2));
+}
+
+TEST_F(CompactionPickerTest, UniversalIncrementalSpace4) {
+  // Test compaction candidates always cover many files.
+  const uint64_t kFileSize = 100000;
+
+  mutable_cf_options_.max_compaction_bytes = 3200000;
+  mutable_cf_options_.compaction_options_universal.incremental = true;
+  mutable_cf_options_.compaction_options_universal
+      .max_size_amplification_percent = 30;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(2, 2U, "010", "080", kFileSize, 0, 200, 251);
+
+  // Generate files like following:
+  // L3: (1101, 1180) (1201, 1280) ... (7901, 7908)
+  // L4: (1130, 1150) (1160, 1210) (1230, 1250) (1260 1310) ... (7960, 8010)
+  for (int i = 11; i < 79; i++) {
+    Add(3, 100 + i * 3, ToString(i * 100).c_str(),
+        ToString(i * 100 + 80).c_str(), kFileSize, 0, 200, 251);
+    // Add a tie breaker
+    if (i == 66) {
+      Add(3, 10000U, "6690", "6699", kFileSize, 0, 200, 251);
+    }
+
+    Add(4, 100 + i * 3 + 1, ToString(i * 100 + 30).c_str(),
+        ToString(i * 100 + 50).c_str(), kFileSize, 0, 200, 251);
+    Add(4, 100 + i * 3 + 2, ToString(i * 100 + 60).c_str(),
+        ToString(i * 100 + 110).c_str(), kFileSize, 0, 200, 251);
+  }
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+          &log_buffer_));
+  ASSERT_TRUE(compaction);
+  ASSERT_EQ(4, compaction->output_level());
+  ASSERT_EQ(3, compaction->start_level());
+  ASSERT_EQ(6U, compaction->num_input_files(0));
+  ASSERT_EQ(100 + 62U * 3, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(10000U, compaction->input(0, 5)->fd.GetNumber());
+  ASSERT_EQ(11, compaction->num_input_files(1));
+}
+
+TEST_F(CompactionPickerTest, UniversalIncrementalSpace5) {
+  // Test compaction candidates always cover many files with some single
+  // files larger than size threshold.
+  const uint64_t kFileSize = 100000;
+
+  mutable_cf_options_.max_compaction_bytes = 3200000;
+  mutable_cf_options_.compaction_options_universal.incremental = true;
+  mutable_cf_options_.compaction_options_universal
+      .max_size_amplification_percent = 30;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(2, 2U, "010", "080", kFileSize, 0, 200, 251);
+
+  // Generate files like following:
+  // L3: (1101, 1180) (1201, 1280) ... (7901, 7908)
+  // L4: (1130, 1150) (1160, 1210) (1230, 1250) (1260 1310) ... (7960, 8010)
+  for (int i = 11; i < 70; i++) {
+    Add(3, 100 + i * 3, ToString(i * 100).c_str(),
+        ToString(i * 100 + 80).c_str(),
+        i % 10 == 9 ? kFileSize * 100 : kFileSize, 0, 200, 251);
+
+    Add(4, 100 + i * 3 + 1, ToString(i * 100 + 30).c_str(),
+        ToString(i * 100 + 50).c_str(), kFileSize, 0, 200, 251);
+    Add(4, 100 + i * 3 + 2, ToString(i * 100 + 60).c_str(),
+        ToString(i * 100 + 110).c_str(), kFileSize, 0, 200, 251);
+  }
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+          &log_buffer_));
+  ASSERT_TRUE(compaction);
+  ASSERT_EQ(4, compaction->output_level());
+  ASSERT_EQ(3, compaction->start_level());
+  ASSERT_EQ(6U, compaction->num_input_files(0));
+  ASSERT_EQ(100 + 14 * 3, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(100 + 19 * 3, compaction->input(0, 5)->fd.GetNumber());
+  ASSERT_EQ(13, compaction->num_input_files(1));
+}
+
 TEST_F(CompactionPickerTest, NeedsCompactionFIFO) {
  NewVersionStorage(1, kCompactionStyleFIFO);
  const int kFileCount =
@@ -757,6 +976,245 @@ TEST_F(CompactionPickerTest, NeedsCompactionFIFO) {
              vstorage_->CompactionScore(0) >= 1);
  }
 }
+
+TEST_F(CompactionPickerTest, FIFOToWarm1) {
+  NewVersionStorage(1, kCompactionStyleFIFO);
+  const uint64_t kFileSize = 100000;
+  const uint64_t kMaxSize = kFileSize * 100000;
+  uint64_t kWarmThreshold = 2000;
+
+  fifo_options_.max_table_files_size = kMaxSize;
+  fifo_options_.age_for_warm = kWarmThreshold;
+  mutable_cf_options_.compaction_options_fifo = fifo_options_;
+  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
+  mutable_cf_options_.max_compaction_bytes = kFileSize * 100;
+  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
+
+  int64_t current_time = 0;
+  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
+  uint64_t threshold_time =
+      static_cast<uint64_t>(current_time) - kWarmThreshold;
+  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
+      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
+  Add(0, 5U, "240", "290", 2 * kFileSize, 0, 2700, 2800, 0, true,
+      Temperature::kUnknown, threshold_time + 100);
+  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
+      Temperature::kUnknown, threshold_time - 2000);
+  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
+      Temperature::kUnknown, threshold_time - 3000);
+  UpdateVersionStorageInfo();
+
+  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
+  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+      &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(3U, compaction->input(0, 0)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, FIFOToWarm2) {
+  NewVersionStorage(1, kCompactionStyleFIFO);
+  const uint64_t kFileSize = 100000;
+  const uint64_t kMaxSize = kFileSize * 100000;
+  uint64_t kWarmThreshold = 2000;
+
+  fifo_options_.max_table_files_size = kMaxSize;
+  fifo_options_.age_for_warm = kWarmThreshold;
+  mutable_cf_options_.compaction_options_fifo = fifo_options_;
+  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
+  mutable_cf_options_.max_compaction_bytes = kFileSize * 100;
+  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
+
+  int64_t current_time = 0;
+  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
+  uint64_t threshold_time =
+      static_cast<uint64_t>(current_time) - kWarmThreshold;
+  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
+      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
+  Add(0, 5U, "240", "290", 2 * kFileSize, 0, 2700, 2800, 0, true,
+      Temperature::kUnknown, threshold_time + 100);
+  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
+      Temperature::kUnknown, threshold_time - 2000);
+  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
+      Temperature::kUnknown, threshold_time - 3000);
+  Add(0, 2U, "200", "300", 4 * kFileSize, 0, 2100, 2200, 0, true,
+      Temperature::kUnknown, threshold_time - 4000);
+  UpdateVersionStorageInfo();
+
+  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
+  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+      &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(2U, compaction->num_input_files(0));
+  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(3U, compaction->input(0, 1)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, FIFOToWarmMaxSize) {
+  NewVersionStorage(1, kCompactionStyleFIFO);
+  const uint64_t kFileSize = 100000;
+  const uint64_t kMaxSize = kFileSize * 100000;
+  uint64_t kWarmThreshold = 2000;
+
+  fifo_options_.max_table_files_size = kMaxSize;
+  fifo_options_.age_for_warm = kWarmThreshold;
+  mutable_cf_options_.compaction_options_fifo = fifo_options_;
+  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
+  mutable_cf_options_.max_compaction_bytes = kFileSize * 9;
+  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
+
+  int64_t current_time = 0;
+  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
+  uint64_t threshold_time =
+      static_cast<uint64_t>(current_time) - kWarmThreshold;
+  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
+      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
+  Add(0, 5U, "240", "290", 2 * kFileSize, 0, 2700, 2800, 0, true,
+      Temperature::kUnknown, threshold_time + 100);
+  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
+      Temperature::kUnknown, threshold_time - 2000);
+  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
+      Temperature::kUnknown, threshold_time - 3000);
+  Add(0, 2U, "200", "300", 4 * kFileSize, 0, 2100, 2200, 0, true,
+      Temperature::kUnknown, threshold_time - 4000);
+  Add(0, 1U, "200", "300", 4 * kFileSize, 0, 2000, 2100, 0, true,
+      Temperature::kUnknown, threshold_time - 5000);
+  UpdateVersionStorageInfo();
+
+  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
+  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+      &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(2U, compaction->num_input_files(0));
+  ASSERT_EQ(1U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(2U, compaction->input(0, 1)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, FIFOToWarmWithExistingWarm) {
+  NewVersionStorage(1, kCompactionStyleFIFO);
+  const uint64_t kFileSize = 100000;
+  const uint64_t kMaxSize = kFileSize * 100000;
+  uint64_t kWarmThreshold = 2000;
+
+  fifo_options_.max_table_files_size = kMaxSize;
+  fifo_options_.age_for_warm = kWarmThreshold;
+  mutable_cf_options_.compaction_options_fifo = fifo_options_;
+  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
+  mutable_cf_options_.max_compaction_bytes = kFileSize * 100;
+  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
+
+  int64_t current_time = 0;
+  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
+  uint64_t threshold_time =
+      static_cast<uint64_t>(current_time) - kWarmThreshold;
+  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
+      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
+  Add(0, 5U, "240", "290", 2 * kFileSize, 0, 2700, 2800, 0, true,
+      Temperature::kUnknown, threshold_time + 100);
+  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
+      Temperature::kUnknown, threshold_time - 2000);
+  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
+      Temperature::kUnknown, threshold_time - 3000);
+  Add(0, 2U, "200", "300", 4 * kFileSize, 0, 2100, 2200, 0, true,
+      Temperature::kUnknown, threshold_time - 4000);
+  Add(0, 1U, "200", "300", 4 * kFileSize, 0, 2000, 2100, 0, true,
+      Temperature::kWarm, threshold_time - 5000);
+  UpdateVersionStorageInfo();
+
+  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
+  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+      &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(2U, compaction->num_input_files(0));
+  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(3U, compaction->input(0, 1)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, FIFOToWarmWithOngoing) {
+  NewVersionStorage(1, kCompactionStyleFIFO);
+  const uint64_t kFileSize = 100000;
+  const uint64_t kMaxSize = kFileSize * 100000;
+  uint64_t kWarmThreshold = 2000;
+
+  fifo_options_.max_table_files_size = kMaxSize;
+  fifo_options_.age_for_warm = kWarmThreshold;
+  mutable_cf_options_.compaction_options_fifo = fifo_options_;
+  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
+  mutable_cf_options_.max_compaction_bytes = kFileSize * 100;
+  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
+
+  int64_t current_time = 0;
+  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
+  uint64_t threshold_time =
+      static_cast<uint64_t>(current_time) - kWarmThreshold;
+  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
+      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
+  Add(0, 5U, "240", "290", 2 * kFileSize, 0, 2700, 2800, 0, true,
+      Temperature::kUnknown, threshold_time + 100);
+  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
+      Temperature::kUnknown, threshold_time - 2000);
+  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
+      Temperature::kUnknown, threshold_time - 3000);
+  Add(0, 2U, "200", "300", 4 * kFileSize, 0, 2100, 2200, 0, true,
+      Temperature::kUnknown, threshold_time - 4000);
+  Add(0, 1U, "200", "300", 4 * kFileSize, 0, 2000, 2100, 0, true,
+      Temperature::kWarm, threshold_time - 5000);
+  file_map_[2].first->being_compacted = true;
+  UpdateVersionStorageInfo();
+
+  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
+  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+      &log_buffer_));
+  // Stop if a file is being compacted
+  ASSERT_TRUE(compaction.get() == nullptr);
+}
+
+TEST_F(CompactionPickerTest, FIFOToWarmWithHotBetweenWarms) {
+  NewVersionStorage(1, kCompactionStyleFIFO);
+  const uint64_t kFileSize = 100000;
+  const uint64_t kMaxSize = kFileSize * 100000;
+  uint64_t kWarmThreshold = 2000;
+
+  fifo_options_.max_table_files_size = kMaxSize;
+  fifo_options_.age_for_warm = kWarmThreshold;
+  mutable_cf_options_.compaction_options_fifo = fifo_options_;
+  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
+  mutable_cf_options_.max_compaction_bytes = kFileSize * 100;
+  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
+
+  int64_t current_time = 0;
+  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
+  uint64_t threshold_time =
+      static_cast<uint64_t>(current_time) - kWarmThreshold;
+  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
+      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
+  Add(0, 5U, "240", "290", 2 * kFileSize, 0, 2700, 2800, 0, true,
+      Temperature::kUnknown, threshold_time + 100);
+  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
+      Temperature::kUnknown, threshold_time - 2000);
+  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
+      Temperature::kWarm, threshold_time - 3000);
+  Add(0, 2U, "200", "300", 4 * kFileSize, 0, 2100, 2200, 0, true,
+      Temperature::kUnknown, threshold_time - 4000);
+  Add(0, 1U, "200", "300", 4 * kFileSize, 0, 2000, 2100, 0, true,
+      Temperature::kWarm, threshold_time - 5000);
+  UpdateVersionStorageInfo();
+
+  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
+  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
+      &log_buffer_));
+  // Stop if a file is being compacted
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
+}
+
 #endif  // ROCKSDB_LITE

 TEST_F(CompactionPickerTest, CompactionPriMinOverlapping1) {
@@ -15,9 +15,11 @@
 #include <queue>
 #include <string>
 #include <utility>
+
 #include "db/column_family.h"
 #include "file/filename.h"
 #include "logging/log_buffer.h"
+#include "logging/logging.h"
 #include "monitoring/statistics.h"
 #include "test_util/sync_point.h"
 #include "util/random.h"
@@ -32,7 +34,7 @@ namespace {
 class UniversalCompactionBuilder {
 public:
  UniversalCompactionBuilder(
-      const ImmutableCFOptions& ioptions, const InternalKeyComparator* icmp,
+      const ImmutableOptions& ioptions, const InternalKeyComparator* icmp,
      const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
      const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
      UniversalCompactionPicker* picker, LogBuffer* log_buffer)
@@ -87,6 +89,14 @@ class UniversalCompactionBuilder {
  // Pick Universal compaction to limit space amplification.
  Compaction* PickCompactionToReduceSizeAmp();

+  // Try to pick incremental compaction to reduce space amplification.
+  // It will return null if it cannot find a fanout within the threshold.
+  // Fanout is defined as
+  //    total size of files to compact at output level
+  //  --------------------------------------------------
+  //    total size of files to compact at other levels
+  Compaction* PickIncrementalForReduceSizeAmp(double fanout_threshold);
+
  Compaction* PickDeleteTriggeredCompaction();

  // Form a compaction from the sorted run indicated by start_index to the
@@ -102,13 +112,15 @@ class UniversalCompactionBuilder {
  // because some files are being compacted.
  Compaction* PickPeriodicCompaction();

-  // Used in universal compaction when the enabled_trivial_move
+  // Used in universal compaction when the allow_trivial_move
  // option is set. Checks whether there are any overlapping files
  // in the input. Returns true if the input files are non
  // overlapping.
  bool IsInputFilesNonOverlapping(Compaction* c);

-  const ImmutableCFOptions& ioptions_;
+  uint64_t GetMaxOverlappingBytes() const;
+
+  const ImmutableOptions& ioptions_;
  const InternalKeyComparator* icmp_;
  double score_;
  std::vector<SortedRun> sorted_runs_;
@@ -157,9 +169,9 @@ struct SmallestKeyHeapComparator {
  const Comparator* ucmp_;
 };

-typedef std::priority_queue<InputFileInfo, std::vector<InputFileInfo>,
-                            SmallestKeyHeapComparator>
-    SmallestKeyHeap;
+using SmallestKeyHeap =
+    std::priority_queue<InputFileInfo, std::vector<InputFileInfo>,
+                        SmallestKeyHeapComparator>;

 // This function creates the heap that is used to find if the files are
 // overlapping during universal compaction when the allow_trivial_move
@@ -486,7 +498,7 @@ Compaction* UniversalCompactionBuilder::PickCompaction() {
  }
 #endif
  // update statistics
-  RecordInHistogram(ioptions_.statistics, NUM_FILES_IN_SINGLE_COMPACTION,
+  RecordInHistogram(ioptions_.stats, NUM_FILES_IN_SINGLE_COMPACTION,
                    c->inputs(0)->size());

  picker_->RegisterCompaction(c);
@@ -712,6 +724,19 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSortedRuns(
                     cf_name_.c_str(), file_num_buf);
  }

+  std::vector<FileMetaData*> grandparents;
+  // Include grandparents for potential file cutting in incremental
+  // mode. It is for aligning file cutting boundaries across levels,
+  // so that subsequent compactions can pick files with aligned
+  // buffer.
+  // Single files are only picked up in incremental mode, so that
+  // there is no need for full range.
+  if (mutable_cf_options_.compaction_options_universal.incremental &&
+      first_index_after < sorted_runs_.size() &&
+      sorted_runs_[first_index_after].level > 1) {
+    grandparents = vstorage_->LevelFiles(sorted_runs_[first_index_after].level);
+  }
+
  CompactionReason compaction_reason;
  if (max_number_of_files_to_compact == UINT_MAX) {
    compaction_reason = CompactionReason::kUniversalSizeRatio;
@@ -723,13 +748,14 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSortedRuns(
      std::move(inputs), output_level,
      MaxFileSizeForLevel(mutable_cf_options_, output_level,
                          kCompactionStyleUniversal),
-      LLONG_MAX, path_id,
+      GetMaxOverlappingBytes(), path_id,
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_, start_level,
                         1, enable_compression),
      GetCompressionOptions(mutable_cf_options_, vstorage_, start_level,
                            enable_compression),
-      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
-      score_, false /* deletion_compaction */, compaction_reason);
+      Temperature::kUnknown,
+      /* max_subcompactions */ 0, grandparents, /* is manual */ false, score_,
+      false /* deletion_compaction */, compaction_reason);
 }

 // Look at overall size amplification. If size amplification
@@ -785,6 +811,8 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSizeAmp() {
  for (size_t loop = start_index; loop + 1 < sorted_runs_.size(); loop++) {
    sr = &sorted_runs_[loop];
    if (sr->being_compacted) {
+      // TODO with incremental compaction is supported, we might want to
+      // schedule some incremental compactions in parallel if needed.
      char file_num_buf[kFormatFileNumberBufSize];
      sr->Dump(file_num_buf, sizeof(file_num_buf), true);
      ROCKS_LOG_BUFFER(
@@ -818,16 +846,250 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSizeAmp() {
        " earliest-file-size %" PRIu64,
        cf_name_.c_str(), candidate_size, earliest_file_size);
  }
+  // Since incremental compaction can't include more than second last
+  // level, it can introduce penalty, compared to full compaction. We
+  // hard code the pentalty to be 80%. If we end up with a compaction
+  // fanout higher than 80% of full level compactions, we fall back
+  // to full level compaction.
+  // The 80% threshold is arbitrary and can be adjusted or made
+  // configurable in the future.
+  // This also prevent the case when compaction falls behind and we
+  // need to compact more levels for compactions to catch up.
+  if (mutable_cf_options_.compaction_options_universal.incremental) {
+    double fanout_threshold = static_cast<double>(earliest_file_size) /
+                              static_cast<double>(candidate_size) * 1.8;
+    Compaction* picked = PickIncrementalForReduceSizeAmp(fanout_threshold);
+    if (picked != nullptr) {
+      // As the feature is still incremental, picking incremental compaction
+      // might fail and we will fall bck to compacting full level.
+      return picked;
+    }
+  }
  return PickCompactionToOldest(start_index,
                                CompactionReason::kUniversalSizeAmplification);
 }

+Compaction* UniversalCompactionBuilder::PickIncrementalForReduceSizeAmp(
+    double fanout_threshold) {
+  // Try find all potential compactions with total size just over
+  // options.max_compaction_size / 2, and take the one with the lowest
+  // fanout (defined in declaration of the function).
+  // This is done by having a sliding window of the files at the second
+  // lowest level, and keep expanding while finding overlapping in the
+  // last level. Once total size exceeds the size threshold, calculate
+  // the fanout value. And then shrinking from the small side of the
+  // window. Keep doing it until the end.
+  // Finally, we try to include upper level files if they fall into
+  // the range.
+  //
+  // Note that it is a similar problem as leveled compaction's
+  // kMinOverlappingRatio priority, but instead of picking single files
+  // we expand to a target compaction size. The reason is that in
+  // leveled compaction, actual fanout value tends to high, e.g. 10, so
+  // even with single file in down merging level, the extra size
+  // compacted in boundary files is at a lower ratio. But here users
+  // often have size of second last level size to be 1/4, 1/3 or even
+  // 1/2 of the bottommost level, so picking single file in second most
+  // level will cause significant waste, which is not desirable.
+  //
+  // This algorithm has lots of room to improve to pick more efficient
+  // compactions.
+  assert(sorted_runs_.size() >= 2);
+  int second_last_level = sorted_runs_[sorted_runs_.size() - 2].level;
+  if (second_last_level == 0) {
+    // Can't split Level 0.
+    return nullptr;
+  }
+  int output_level = sorted_runs_.back().level;
+  const std::vector<FileMetaData*>& bottom_files =
+      vstorage_->LevelFiles(output_level);
+  const std::vector<FileMetaData*>& files =
+      vstorage_->LevelFiles(second_last_level);
+  assert(!bottom_files.empty());
+  assert(!files.empty());
+
+  //  std::unordered_map<uint64_t, uint64_t> file_to_order;
+
+  int picked_start_idx = 0;
+  int picked_end_idx = 0;
+  double picked_fanout = fanout_threshold;
+
+  // Use half target compaction bytes as anchor to stop growing second most
+  // level files, and reserve growing space for more overlapping bottom level,
+  // clean cut, files from other levels, etc.
+  uint64_t comp_thres_size = mutable_cf_options_.max_compaction_bytes / 2;
+  int start_idx = 0;
+  int bottom_end_idx = 0;
+  int bottom_start_idx = 0;
+  uint64_t non_bottom_size = 0;
+  uint64_t bottom_size = 0;
+  bool end_bottom_size_counted = false;
+  for (int end_idx = 0; end_idx < static_cast<int>(files.size()); end_idx++) {
+    FileMetaData* end_file = files[end_idx];
+
+    // Include bottom most level files smaller than the current second
+    // last level file.
+    int num_skipped = 0;
+    while (bottom_end_idx < static_cast<int>(bottom_files.size()) &&
+           icmp_->Compare(bottom_files[bottom_end_idx]->largest,
+                          end_file->smallest) < 0) {
+      if (!end_bottom_size_counted) {
+        bottom_size += bottom_files[bottom_end_idx]->fd.file_size;
+      }
+      bottom_end_idx++;
+      end_bottom_size_counted = false;
+      num_skipped++;
+    }
+
+    if (num_skipped > 1) {
+      // At least a file in the bottom most level falls into the file gap. No
+      // reason to include the file. We cut the range and start a new sliding
+      // window.
+      start_idx = end_idx;
+    }
+
+    if (start_idx == end_idx) {
+      // new sliding window.
+      non_bottom_size = 0;
+      bottom_size = 0;
+      bottom_start_idx = bottom_end_idx;
+      end_bottom_size_counted = false;
+    }
+
+    non_bottom_size += end_file->fd.file_size;
+
+    // Include all overlapping files in bottom level.
+    while (bottom_end_idx < static_cast<int>(bottom_files.size()) &&
+           icmp_->Compare(bottom_files[bottom_end_idx]->smallest,
+                          end_file->largest) < 0) {
+      if (!end_bottom_size_counted) {
+        bottom_size += bottom_files[bottom_end_idx]->fd.file_size;
+        end_bottom_size_counted = true;
+      }
+      if (icmp_->Compare(bottom_files[bottom_end_idx]->largest,
+                         end_file->largest) > 0) {
+        // next level file cross large boundary of current file.
+        break;
+      }
+      bottom_end_idx++;
+      end_bottom_size_counted = false;
+    }
+
+    if ((non_bottom_size + bottom_size > comp_thres_size ||
+         end_idx == static_cast<int>(files.size()) - 1) &&
+        non_bottom_size > 0) {  // Do we alow 0 size file at all?
+      // If it is a better compaction, remember it in picked* variables.
+      double fanout = static_cast<double>(bottom_size) /
+                      static_cast<double>(non_bottom_size);
+      if (fanout < picked_fanout) {
+        picked_start_idx = start_idx;
+        picked_end_idx = end_idx;
+        picked_fanout = fanout;
+      }
+      // Shrink from the start end to under comp_thres_size
+      while (non_bottom_size + bottom_size > comp_thres_size &&
+             start_idx <= end_idx) {
+        non_bottom_size -= files[start_idx]->fd.file_size;
+        start_idx++;
+        if (start_idx < static_cast<int>(files.size())) {
+          while (bottom_start_idx <= bottom_end_idx &&
+                 icmp_->Compare(bottom_files[bottom_start_idx]->largest,
+                                files[start_idx]->smallest) < 0) {
+            bottom_size -= bottom_files[bottom_start_idx]->fd.file_size;
+            bottom_start_idx++;
+          }
+        }
+      }
+    }
+  }
+
+  if (picked_fanout >= fanout_threshold) {
+    assert(picked_fanout == fanout_threshold);
+    return nullptr;
+  }
+
+  std::vector<CompactionInputFiles> inputs;
+  CompactionInputFiles bottom_level_inputs;
+  CompactionInputFiles second_last_level_inputs;
+  second_last_level_inputs.level = second_last_level;
+  bottom_level_inputs.level = output_level;
+  for (int i = picked_start_idx; i <= picked_end_idx; i++) {
+    if (files[i]->being_compacted) {
+      return nullptr;
+    }
+    second_last_level_inputs.files.push_back(files[i]);
+  }
+  assert(!second_last_level_inputs.empty());
+  if (!picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
+                                       &second_last_level_inputs,
+                                       /*next_smallest=*/nullptr)) {
+    return nullptr;
+  }
+  // We might be able to avoid this binary search if we save and expand
+  // from bottom_start_idx and bottom_end_idx, but for now, we use
+  // SetupOtherInputs() for simplicity.
+  int parent_index = -1;  // Create and use bottom_start_idx?
+  if (!picker_->SetupOtherInputs(cf_name_, mutable_cf_options_, vstorage_,
+                                 &second_last_level_inputs,
+                                 &bottom_level_inputs, &parent_index,
+                                 /*base_index=*/-1)) {
+    return nullptr;
+  }
+
+  // Try to include files in upper levels if they fall into the range.
+  // Since we need to go from lower level up and this is in the reverse
+  // order, compared to level order, we first write to an reversed
+  // data structure and finally copy them to compaction inputs.
+  InternalKey smallest, largest;
+  picker_->GetRange(second_last_level_inputs, &smallest, &largest);
+  std::vector<CompactionInputFiles> inputs_reverse;
+  for (auto it = ++(++sorted_runs_.rbegin()); it != sorted_runs_.rend(); it++) {
+    SortedRun& sr = *it;
+    if (sr.level == 0) {
+      break;
+    }
+    std::vector<FileMetaData*> level_inputs;
+    vstorage_->GetCleanInputsWithinInterval(sr.level, &smallest, &largest,
+                                            &level_inputs);
+    if (!level_inputs.empty()) {
+      inputs_reverse.push_back({});
+      inputs_reverse.back().level = sr.level;
+      inputs_reverse.back().files = level_inputs;
+      picker_->GetRange(inputs_reverse.back(), &smallest, &largest);
+    }
+  }
+  for (auto it = inputs_reverse.rbegin(); it != inputs_reverse.rend(); it++) {
+    inputs.push_back(*it);
+  }
+
+  inputs.push_back(second_last_level_inputs);
+  inputs.push_back(bottom_level_inputs);
+
+  // TODO support multi paths?
+  uint32_t path_id = 0;
+  return new Compaction(
+      vstorage_, ioptions_, mutable_cf_options_, mutable_db_options_,
+      std::move(inputs), output_level,
+      MaxFileSizeForLevel(mutable_cf_options_, output_level,
+                          kCompactionStyleUniversal),
+      GetMaxOverlappingBytes(), path_id,
+      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
+                         output_level, 1, true /* enable_compression */),
+      GetCompressionOptions(mutable_cf_options_, vstorage_, output_level,
+                            true /* enable_compression */),
+      Temperature::kUnknown,
+      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
+      score_, false /* deletion_compaction */,
+      CompactionReason::kUniversalSizeAmplification);
+}
+
 // Pick files marked for compaction. Typically, files are marked by
 // CompactOnDeleteCollector due to the presence of tombstones.
 Compaction* UniversalCompactionBuilder::PickDeleteTriggeredCompaction() {
  CompactionInputFiles start_level_inputs;
  int output_level;
  std::vector<CompactionInputFiles> inputs;
+  std::vector<FileMetaData*> grandparents;

  if (vstorage_->num_levels() == 1) {
    // This is single level universal. Since we're basically trying to reclaim
@@ -934,6 +1196,9 @@ Compaction* UniversalCompactionBuilder::PickDeleteTriggeredCompaction() {
      if (picker_->FilesRangeOverlapWithCompaction(inputs, output_level)) {
        return nullptr;
      }
+
+      picker_->GetGrandparents(vstorage_, start_level_inputs,
+                               output_level_inputs, &grandparents);
    } else {
      inputs.push_back(start_level_inputs);
    }
@@ -951,12 +1216,13 @@ Compaction* UniversalCompactionBuilder::PickDeleteTriggeredCompaction() {
      std::move(inputs), output_level,
      MaxFileSizeForLevel(mutable_cf_options_, output_level,
                          kCompactionStyleUniversal),
-      /* max_grandparent_overlap_bytes */ LLONG_MAX, path_id,
+      /* max_grandparent_overlap_bytes */ GetMaxOverlappingBytes(), path_id,
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
                         output_level, 1),
      GetCompressionOptions(mutable_cf_options_, vstorage_, output_level),
-      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
-      score_, false /* deletion_compaction */,
+      Temperature::kUnknown,
+      /* max_subcompactions */ 0, grandparents, /* is manual */ false, score_,
+      false /* deletion_compaction */,
      CompactionReason::kFilesMarkedForCompaction);
 }

@@ -1024,11 +1290,12 @@ Compaction* UniversalCompactionBuilder::PickCompactionToOldest(
      std::move(inputs), output_level,
      MaxFileSizeForLevel(mutable_cf_options_, output_level,
                          kCompactionStyleUniversal),
-      LLONG_MAX, path_id,
+      GetMaxOverlappingBytes(), path_id,
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
                         output_level, 1, true /* enable_compression */),
      GetCompressionOptions(mutable_cf_options_, vstorage_, output_level,
                            true /* enable_compression */),
+      Temperature::kUnknown,
      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
      score_, false /* deletion_compaction */, compaction_reason);
 }
@@ -1098,6 +1365,17 @@ Compaction* UniversalCompactionBuilder::PickPeriodicCompaction() {

  return c;
 }
+
+uint64_t UniversalCompactionBuilder::GetMaxOverlappingBytes() const {
+  if (!mutable_cf_options_.compaction_options_universal.incremental) {
+    return port::kMaxUint64;
+  } else {
+    // Try to align cutting boundary with files at the next level if the
+    // file isn't end up with 1/2 of target size, or it would overlap
+    // with two full size files at the next level.
+    return mutable_cf_options_.target_file_size_base / 2 * 3;
+  }
+}
 }  // namespace ROCKSDB_NAMESPACE

 #endif  // !ROCKSDB_LITE
@@ -15,7 +15,7 @@
 namespace ROCKSDB_NAMESPACE {
 class UniversalCompactionPicker : public CompactionPicker {
 public:
-  UniversalCompactionPicker(const ImmutableCFOptions& ioptions,
+  UniversalCompactionPicker(const ImmutableOptions& ioptions,
                            const InternalKeyComparator* icmp)
      : CompactionPicker(ioptions, icmp) {}
  virtual Compaction* PickCompaction(
@@ -0,0 +1,833 @@
+//  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).
+
+#ifndef ROCKSDB_LITE
+
+#include "db/db_test_util.h"
+#include "port/stack_trace.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class TestCompactionServiceBase {
+ public:
+  virtual int GetCompactionNum() = 0;
+
+  void OverrideStartStatus(CompactionServiceJobStatus s) {
+    is_override_start_status = true;
+    override_start_status = s;
+  }
+
+  void OverrideWaitStatus(CompactionServiceJobStatus s) {
+    is_override_wait_status = true;
+    override_wait_status = s;
+  }
+
+  void OverrideWaitResult(std::string str) {
+    is_override_wait_result = true;
+    override_wait_result = std::move(str);
+  }
+
+  void ResetOverride() {
+    is_override_wait_result = false;
+    is_override_start_status = false;
+    is_override_wait_status = false;
+  }
+
+  virtual ~TestCompactionServiceBase() = default;
+
+ protected:
+  bool is_override_start_status = false;
+  CompactionServiceJobStatus override_start_status =
+      CompactionServiceJobStatus::kFailure;
+  bool is_override_wait_status = false;
+  CompactionServiceJobStatus override_wait_status =
+      CompactionServiceJobStatus::kFailure;
+  bool is_override_wait_result = false;
+  std::string override_wait_result;
+};
+
+class MyTestCompactionServiceLegacy : public CompactionService,
+                                      public TestCompactionServiceBase {
+ public:
+  MyTestCompactionServiceLegacy(std::string db_path, Options& options,
+                                std::shared_ptr<Statistics>& statistics)
+      : db_path_(std::move(db_path)),
+        options_(options),
+        statistics_(statistics) {}
+
+  static const char* kClassName() { return "MyTestCompactionServiceLegacy"; }
+
+  const char* Name() const override { return kClassName(); }
+
+  CompactionServiceJobStatus Start(const std::string& compaction_service_input,
+                                   uint64_t job_id) override {
+    InstrumentedMutexLock l(&mutex_);
+    jobs_.emplace(job_id, compaction_service_input);
+    CompactionServiceJobStatus s = CompactionServiceJobStatus::kSuccess;
+    if (is_override_start_status) {
+      return override_start_status;
+    }
+    return s;
+  }
+
+  CompactionServiceJobStatus WaitForComplete(
+      uint64_t job_id, std::string* compaction_service_result) override {
+    std::string compaction_input;
+    {
+      InstrumentedMutexLock l(&mutex_);
+      auto i = jobs_.find(job_id);
+      if (i == jobs_.end()) {
+        return CompactionServiceJobStatus::kFailure;
+      }
+      compaction_input = std::move(i->second);
+      jobs_.erase(i);
+    }
+
+    if (is_override_wait_status) {
+      return override_wait_status;
+    }
+
+    CompactionServiceOptionsOverride options_override;
+    options_override.env = options_.env;
+    options_override.file_checksum_gen_factory =
+        options_.file_checksum_gen_factory;
+    options_override.comparator = options_.comparator;
+    options_override.merge_operator = options_.merge_operator;
+    options_override.compaction_filter = options_.compaction_filter;
+    options_override.compaction_filter_factory =
+        options_.compaction_filter_factory;
+    options_override.prefix_extractor = options_.prefix_extractor;
+    options_override.table_factory = options_.table_factory;
+    options_override.sst_partitioner_factory = options_.sst_partitioner_factory;
+    options_override.statistics = statistics_;
+
+    Status s = DB::OpenAndCompact(
+        db_path_, db_path_ + "/" + ROCKSDB_NAMESPACE::ToString(job_id),
+        compaction_input, compaction_service_result, options_override);
+    if (is_override_wait_result) {
+      *compaction_service_result = override_wait_result;
+    }
+    compaction_num_.fetch_add(1);
+    if (s.ok()) {
+      return CompactionServiceJobStatus::kSuccess;
+    } else {
+      return CompactionServiceJobStatus::kFailure;
+    }
+  }
+
+  int GetCompactionNum() override { return compaction_num_.load(); }
+
+ private:
+  InstrumentedMutex mutex_;
+  std::atomic_int compaction_num_{0};
+  std::map<uint64_t, std::string> jobs_;
+  const std::string db_path_;
+  Options options_;
+  std::shared_ptr<Statistics> statistics_;
+};
+
+class MyTestCompactionService : public CompactionService,
+                                public TestCompactionServiceBase {
+ public:
+  MyTestCompactionService(std::string db_path, Options& options,
+                          std::shared_ptr<Statistics>& statistics)
+      : db_path_(std::move(db_path)),
+        options_(options),
+        statistics_(statistics),
+        start_info_("na", "na", "na", 0, Env::TOTAL),
+        wait_info_("na", "na", "na", 0, Env::TOTAL) {}
+
+  static const char* kClassName() { return "MyTestCompactionService"; }
+
+  const char* Name() const override { return kClassName(); }
+
+  CompactionServiceJobStatus StartV2(
+      const CompactionServiceJobInfo& info,
+      const std::string& compaction_service_input) override {
+    InstrumentedMutexLock l(&mutex_);
+    start_info_ = info;
+    assert(info.db_name == db_path_);
+    jobs_.emplace(info.job_id, compaction_service_input);
+    CompactionServiceJobStatus s = CompactionServiceJobStatus::kSuccess;
+    if (is_override_start_status) {
+      return override_start_status;
+    }
+    return s;
+  }
+
+  CompactionServiceJobStatus WaitForCompleteV2(
+      const CompactionServiceJobInfo& info,
+      std::string* compaction_service_result) override {
+    std::string compaction_input;
+    assert(info.db_name == db_path_);
+    {
+      InstrumentedMutexLock l(&mutex_);
+      wait_info_ = info;
+      auto i = jobs_.find(info.job_id);
+      if (i == jobs_.end()) {
+        return CompactionServiceJobStatus::kFailure;
+      }
+      compaction_input = std::move(i->second);
+      jobs_.erase(i);
+    }
+
+    if (is_override_wait_status) {
+      return override_wait_status;
+    }
+
+    CompactionServiceOptionsOverride options_override;
+    options_override.env = options_.env;
+    options_override.file_checksum_gen_factory =
+        options_.file_checksum_gen_factory;
+    options_override.comparator = options_.comparator;
+    options_override.merge_operator = options_.merge_operator;
+    options_override.compaction_filter = options_.compaction_filter;
+    options_override.compaction_filter_factory =
+        options_.compaction_filter_factory;
+    options_override.prefix_extractor = options_.prefix_extractor;
+    options_override.table_factory = options_.table_factory;
+    options_override.sst_partitioner_factory = options_.sst_partitioner_factory;
+    options_override.statistics = statistics_;
+
+    Status s = DB::OpenAndCompact(
+        db_path_, db_path_ + "/" + ROCKSDB_NAMESPACE::ToString(info.job_id),
+        compaction_input, compaction_service_result, options_override);
+    if (is_override_wait_result) {
+      *compaction_service_result = override_wait_result;
+    }
+    compaction_num_.fetch_add(1);
+    if (s.ok()) {
+      return CompactionServiceJobStatus::kSuccess;
+    } else {
+      return CompactionServiceJobStatus::kFailure;
+    }
+  }
+
+  int GetCompactionNum() override { return compaction_num_.load(); }
+
+  CompactionServiceJobInfo GetCompactionInfoForStart() { return start_info_; }
+  CompactionServiceJobInfo GetCompactionInfoForWait() { return wait_info_; }
+
+ private:
+  InstrumentedMutex mutex_;
+  std::atomic_int compaction_num_{0};
+  std::map<uint64_t, std::string> jobs_;
+  const std::string db_path_;
+  Options options_;
+  std::shared_ptr<Statistics> statistics_;
+  CompactionServiceJobInfo start_info_;
+  CompactionServiceJobInfo wait_info_;
+};
+
+// This is only for listing test classes
+enum TestCompactionServiceType {
+  MyTestCompactionServiceType,
+  MyTestCompactionServiceLegacyType,
+};
+
+class CompactionServiceTest
+    : public DBTestBase,
+      public testing::WithParamInterface<TestCompactionServiceType> {
+ public:
+  explicit CompactionServiceTest()
+      : DBTestBase("compaction_service_test", true) {}
+
+ protected:
+  void ReopenWithCompactionService(Options* options) {
+    options->env = env_;
+    primary_statistics_ = CreateDBStatistics();
+    options->statistics = primary_statistics_;
+    compactor_statistics_ = CreateDBStatistics();
+    TestCompactionServiceType cs_type = GetParam();
+    switch (cs_type) {
+      case MyTestCompactionServiceType:
+        compaction_service_ = std::make_shared<MyTestCompactionService>(
+            dbname_, *options, compactor_statistics_);
+        break;
+      case MyTestCompactionServiceLegacyType:
+        compaction_service_ = std::make_shared<MyTestCompactionServiceLegacy>(
+            dbname_, *options, compactor_statistics_);
+        break;
+      default:
+        assert(false);
+    }
+    options->compaction_service = compaction_service_;
+    DestroyAndReopen(*options);
+  }
+
+  Statistics* GetCompactorStatistics() { return compactor_statistics_.get(); }
+
+  Statistics* GetPrimaryStatistics() { return primary_statistics_.get(); }
+
+  TestCompactionServiceBase* GetCompactionService() {
+    CompactionService* cs = compaction_service_.get();
+    return dynamic_cast<TestCompactionServiceBase*>(cs);
+  }
+
+  void GenerateTestData() {
+    // Generate 20 files @ L2
+    for (int i = 0; i < 20; i++) {
+      for (int j = 0; j < 10; j++) {
+        int key_id = i * 10 + j;
+        ASSERT_OK(Put(Key(key_id), "value" + ToString(key_id)));
+      }
+      ASSERT_OK(Flush());
+    }
+    MoveFilesToLevel(2);
+
+    // Generate 10 files @ L1 overlap with all 20 files @ L2
+    for (int i = 0; i < 10; i++) {
+      for (int j = 0; j < 10; j++) {
+        int key_id = i * 20 + j * 2;
+        ASSERT_OK(Put(Key(key_id), "value_new" + ToString(key_id)));
+      }
+      ASSERT_OK(Flush());
+    }
+    MoveFilesToLevel(1);
+    ASSERT_EQ(FilesPerLevel(), "0,10,20");
+  }
+
+  void VerifyTestData() {
+    for (int i = 0; i < 200; i++) {
+      auto result = Get(Key(i));
+      if (i % 2) {
+        ASSERT_EQ(result, "value" + ToString(i));
+      } else {
+        ASSERT_EQ(result, "value_new" + ToString(i));
+      }
+    }
+  }
+
+ private:
+  std::shared_ptr<Statistics> compactor_statistics_;
+  std::shared_ptr<Statistics> primary_statistics_;
+  std::shared_ptr<CompactionService> compaction_service_;
+};
+
+TEST_P(CompactionServiceTest, BasicCompactions) {
+  Options options = CurrentOptions();
+  ReopenWithCompactionService(&options);
+
+  Statistics* primary_statistics = GetPrimaryStatistics();
+  Statistics* compactor_statistics = GetCompactorStatistics();
+
+  for (int i = 0; i < 20; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 20 + j * 2;
+      ASSERT_OK(Put(Key(key_id), "value_new" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+
+  // verify result
+  for (int i = 0; i < 200; i++) {
+    auto result = Get(Key(i));
+    if (i % 2) {
+      ASSERT_EQ(result, "value" + ToString(i));
+    } else {
+      ASSERT_EQ(result, "value_new" + ToString(i));
+    }
+  }
+  auto my_cs = GetCompactionService();
+  ASSERT_GE(my_cs->GetCompactionNum(), 1);
+
+  // make sure the compaction statistics is only recorded on the remote side
+  ASSERT_GE(compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES), 1);
+  ASSERT_GE(compactor_statistics->getTickerCount(COMPACT_READ_BYTES), 1);
+  ASSERT_EQ(primary_statistics->getTickerCount(COMPACT_WRITE_BYTES), 0);
+  // even with remote compaction, primary host still needs to read SST files to
+  // `verify_table()`.
+  ASSERT_GE(primary_statistics->getTickerCount(COMPACT_READ_BYTES), 1);
+  // all the compaction write happens on the remote side
+  ASSERT_EQ(primary_statistics->getTickerCount(REMOTE_COMPACT_WRITE_BYTES),
+            compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES));
+  ASSERT_GE(primary_statistics->getTickerCount(REMOTE_COMPACT_READ_BYTES), 1);
+  ASSERT_GT(primary_statistics->getTickerCount(COMPACT_READ_BYTES),
+            primary_statistics->getTickerCount(REMOTE_COMPACT_READ_BYTES));
+  // compactor is already the remote side, which doesn't have remote
+  ASSERT_EQ(compactor_statistics->getTickerCount(REMOTE_COMPACT_READ_BYTES), 0);
+  ASSERT_EQ(compactor_statistics->getTickerCount(REMOTE_COMPACT_WRITE_BYTES),
+            0);
+
+  // Test failed compaction
+  SyncPoint::GetInstance()->SetCallBack(
+      "DBImplSecondary::CompactWithoutInstallation::End", [&](void* status) {
+        // override job status
+        auto s = static_cast<Status*>(status);
+        *s = Status::Aborted("MyTestCompactionService failed to compact!");
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  Status s;
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 20 + j * 2;
+      s = Put(Key(key_id), "value_new" + ToString(key_id));
+      if (s.IsAborted()) {
+        break;
+      }
+    }
+    if (s.IsAborted()) {
+      break;
+    }
+    s = Flush();
+    if (s.IsAborted()) {
+      break;
+    }
+    s = dbfull()->TEST_WaitForCompact();
+    if (s.IsAborted()) {
+      break;
+    }
+  }
+  ASSERT_TRUE(s.IsAborted());
+}
+
+TEST_P(CompactionServiceTest, ManualCompaction) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, &end));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+  VerifyTestData();
+
+  start_str = Key(120);
+  start = start_str;
+  comp_num = my_cs->GetCompactionNum();
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, nullptr));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+  VerifyTestData();
+
+  end_str = Key(92);
+  end = end_str;
+  comp_num = my_cs->GetCompactionNum();
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, &end));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+  VerifyTestData();
+
+  comp_num = my_cs->GetCompactionNum();
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+  VerifyTestData();
+}
+
+TEST_P(CompactionServiceTest, FailedToStart) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+  my_cs->OverrideStartStatus(CompactionServiceJobStatus::kFailure);
+
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  Status s = db_->CompactRange(CompactRangeOptions(), &start, &end);
+  ASSERT_TRUE(s.IsIncomplete());
+}
+
+TEST_P(CompactionServiceTest, InvalidResult) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+  my_cs->OverrideWaitResult("Invalid Str");
+
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  Status s = db_->CompactRange(CompactRangeOptions(), &start, &end);
+  ASSERT_FALSE(s.ok());
+}
+
+TEST_P(CompactionServiceTest, SubCompaction) {
+  Options options = CurrentOptions();
+  options.max_subcompactions = 10;
+  options.target_file_size_base = 1 << 10;  // 1KB
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+
+  GenerateTestData();
+  VerifyTestData();
+
+  auto my_cs = GetCompactionService();
+  int compaction_num_before = my_cs->GetCompactionNum();
+
+  auto cro = CompactRangeOptions();
+  cro.max_subcompactions = 10;
+  Status s = db_->CompactRange(cro, nullptr, nullptr);
+  ASSERT_OK(s);
+  VerifyTestData();
+  int compaction_num = my_cs->GetCompactionNum() - compaction_num_before;
+  // make sure there's sub-compaction by checking the compaction number
+  ASSERT_GE(compaction_num, 2);
+}
+
+class PartialDeleteCompactionFilter : public CompactionFilter {
+ public:
+  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 {
+    int i = std::stoi(key.ToString().substr(3));
+    if (i > 5 && i <= 105) {
+      return CompactionFilter::Decision::kRemove;
+    }
+    return CompactionFilter::Decision::kKeep;
+  }
+
+  const char* Name() const override { return "PartialDeleteCompactionFilter"; }
+};
+
+TEST_P(CompactionServiceTest, CompactionFilter) {
+  Options options = CurrentOptions();
+  std::unique_ptr<CompactionFilter> delete_comp_filter(
+      new PartialDeleteCompactionFilter());
+  options.compaction_filter = delete_comp_filter.get();
+  ReopenWithCompactionService(&options);
+
+  for (int i = 0; i < 20; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 20 + j * 2;
+      ASSERT_OK(Put(Key(key_id), "value_new" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+
+  // verify result
+  for (int i = 0; i < 200; i++) {
+    auto result = Get(Key(i));
+    if (i > 5 && i <= 105) {
+      ASSERT_EQ(result, "NOT_FOUND");
+    } else if (i % 2) {
+      ASSERT_EQ(result, "value" + ToString(i));
+    } else {
+      ASSERT_EQ(result, "value_new" + ToString(i));
+    }
+  }
+  auto my_cs = GetCompactionService();
+  ASSERT_GE(my_cs->GetCompactionNum(), 1);
+}
+
+TEST_P(CompactionServiceTest, Snapshot) {
+  Options options = CurrentOptions();
+  ReopenWithCompactionService(&options);
+
+  ASSERT_OK(Put(Key(1), "value1"));
+  ASSERT_OK(Put(Key(2), "value1"));
+  const Snapshot* s1 = db_->GetSnapshot();
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(Put(Key(1), "value2"));
+  ASSERT_OK(Put(Key(3), "value2"));
+  ASSERT_OK(Flush());
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+  auto my_cs = GetCompactionService();
+  ASSERT_GE(my_cs->GetCompactionNum(), 1);
+  ASSERT_EQ("value1", Get(Key(1), s1));
+  ASSERT_EQ("value2", Get(Key(1)));
+  db_->ReleaseSnapshot(s1);
+}
+
+TEST_P(CompactionServiceTest, ConcurrentCompaction) {
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = 100;
+  options.max_background_jobs = 20;
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  ColumnFamilyMetaData meta;
+  db_->GetColumnFamilyMetaData(&meta);
+
+  std::vector<std::thread> threads;
+  for (const auto& file : meta.levels[1].files) {
+    threads.push_back(std::thread([&]() {
+      std::string fname = file.db_path + "/" + file.name;
+      ASSERT_OK(db_->CompactFiles(CompactionOptions(), {fname}, 2));
+    }));
+  }
+
+  for (auto& thread : threads) {
+    thread.join();
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+
+  // verify result
+  for (int i = 0; i < 200; i++) {
+    auto result = Get(Key(i));
+    if (i % 2) {
+      ASSERT_EQ(result, "value" + ToString(i));
+    } else {
+      ASSERT_EQ(result, "value_new" + ToString(i));
+    }
+  }
+  auto my_cs = GetCompactionService();
+  ASSERT_EQ(my_cs->GetCompactionNum(), 10);
+  ASSERT_EQ(FilesPerLevel(), "0,0,10");
+}
+
+TEST_P(CompactionServiceTest, CompactionInfo) {
+  // only test compaction info for new compaction service interface
+  if (GetParam() != MyTestCompactionServiceType) {
+    return;
+  }
+
+  Options options = CurrentOptions();
+  ReopenWithCompactionService(&options);
+
+  for (int i = 0; i < 20; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 20 + j * 2;
+      ASSERT_OK(Put(Key(key_id), "value_new" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  auto my_cs =
+      static_cast_with_check<MyTestCompactionService>(GetCompactionService());
+  uint64_t comp_num = my_cs->GetCompactionNum();
+  ASSERT_GE(comp_num, 1);
+
+  CompactionServiceJobInfo info = my_cs->GetCompactionInfoForStart();
+  ASSERT_EQ(dbname_, info.db_name);
+  std::string db_id, db_session_id;
+  ASSERT_OK(db_->GetDbIdentity(db_id));
+  ASSERT_EQ(db_id, info.db_id);
+  ASSERT_OK(db_->GetDbSessionId(db_session_id));
+  ASSERT_EQ(db_session_id, info.db_session_id);
+  ASSERT_EQ(Env::LOW, info.priority);
+  info = my_cs->GetCompactionInfoForWait();
+  ASSERT_EQ(dbname_, info.db_name);
+  ASSERT_EQ(db_id, info.db_id);
+  ASSERT_EQ(db_session_id, info.db_session_id);
+  ASSERT_EQ(Env::LOW, info.priority);
+
+  // Test priority USER
+  ColumnFamilyMetaData meta;
+  db_->GetColumnFamilyMetaData(&meta);
+  SstFileMetaData file = meta.levels[1].files[0];
+  ASSERT_OK(db_->CompactFiles(CompactionOptions(),
+                              {file.db_path + "/" + file.name}, 2));
+  info = my_cs->GetCompactionInfoForStart();
+  ASSERT_EQ(Env::USER, info.priority);
+  info = my_cs->GetCompactionInfoForWait();
+  ASSERT_EQ(Env::USER, info.priority);
+
+  // Test priority BOTTOM
+  env_->SetBackgroundThreads(1, Env::BOTTOM);
+  options.num_levels = 2;
+  ReopenWithCompactionService(&options);
+  my_cs =
+      static_cast_with_check<MyTestCompactionService>(GetCompactionService());
+
+  for (int i = 0; i < 20; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  for (int i = 0; i < 4; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 20 + j * 2;
+      ASSERT_OK(Put(Key(key_id), "value_new" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  info = my_cs->GetCompactionInfoForStart();
+  ASSERT_EQ(Env::BOTTOM, info.priority);
+  info = my_cs->GetCompactionInfoForWait();
+  ASSERT_EQ(Env::BOTTOM, info.priority);
+}
+
+TEST_P(CompactionServiceTest, FallbackLocalAuto) {
+  Options options = CurrentOptions();
+  ReopenWithCompactionService(&options);
+
+  auto my_cs = GetCompactionService();
+  Statistics* compactor_statistics = GetCompactorStatistics();
+  Statistics* primary_statistics = GetPrimaryStatistics();
+  uint64_t compactor_write_bytes =
+      compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES);
+  uint64_t primary_write_bytes =
+      primary_statistics->getTickerCount(COMPACT_WRITE_BYTES);
+
+  my_cs->OverrideStartStatus(CompactionServiceJobStatus::kUseLocal);
+
+  for (int i = 0; i < 20; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 20 + j * 2;
+      ASSERT_OK(Put(Key(key_id), "value_new" + ToString(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+
+  // verify result
+  for (int i = 0; i < 200; i++) {
+    auto result = Get(Key(i));
+    if (i % 2) {
+      ASSERT_EQ(result, "value" + ToString(i));
+    } else {
+      ASSERT_EQ(result, "value_new" + ToString(i));
+    }
+  }
+
+  ASSERT_EQ(my_cs->GetCompactionNum(), 0);
+
+  // make sure the compaction statistics is only recorded on the local side
+  ASSERT_EQ(compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES),
+            compactor_write_bytes);
+  ASSERT_GT(primary_statistics->getTickerCount(COMPACT_WRITE_BYTES),
+            primary_write_bytes);
+  ASSERT_EQ(primary_statistics->getTickerCount(REMOTE_COMPACT_READ_BYTES), 0);
+  ASSERT_EQ(primary_statistics->getTickerCount(REMOTE_COMPACT_WRITE_BYTES), 0);
+}
+
+TEST_P(CompactionServiceTest, FallbackLocalManual) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+
+  GenerateTestData();
+  VerifyTestData();
+
+  auto my_cs = GetCompactionService();
+  Statistics* compactor_statistics = GetCompactorStatistics();
+  Statistics* primary_statistics = GetPrimaryStatistics();
+  uint64_t compactor_write_bytes =
+      compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES);
+  uint64_t primary_write_bytes =
+      primary_statistics->getTickerCount(COMPACT_WRITE_BYTES);
+
+  // re-enable remote compaction
+  my_cs->ResetOverride();
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, &end));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+  // make sure the compaction statistics is only recorded on the remote side
+  ASSERT_GT(compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES),
+            compactor_write_bytes);
+  ASSERT_EQ(primary_statistics->getTickerCount(REMOTE_COMPACT_WRITE_BYTES),
+            compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES));
+  ASSERT_EQ(primary_statistics->getTickerCount(COMPACT_WRITE_BYTES),
+            primary_write_bytes);
+
+  // return run local again with API WaitForComplete
+  my_cs->OverrideWaitStatus(CompactionServiceJobStatus::kUseLocal);
+  start_str = Key(120);
+  start = start_str;
+  comp_num = my_cs->GetCompactionNum();
+  compactor_write_bytes =
+      compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES);
+  primary_write_bytes = primary_statistics->getTickerCount(COMPACT_WRITE_BYTES);
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, nullptr));
+  ASSERT_EQ(my_cs->GetCompactionNum(),
+            comp_num);  // no remote compaction is run
+  // make sure the compaction statistics is only recorded on the local side
+  ASSERT_EQ(compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES),
+            compactor_write_bytes);
+  ASSERT_GT(primary_statistics->getTickerCount(COMPACT_WRITE_BYTES),
+            primary_write_bytes);
+  ASSERT_EQ(primary_statistics->getTickerCount(REMOTE_COMPACT_WRITE_BYTES),
+            compactor_write_bytes);
+
+  // verify result after 2 manual compactions
+  VerifyTestData();
+}
+
+INSTANTIATE_TEST_CASE_P(
+    CompactionServiceTest, CompactionServiceTest,
+    ::testing::Values(
+        TestCompactionServiceType::MyTestCompactionServiceType,
+        TestCompactionServiceType::MyTestCompactionServiceLegacyType));
+
+}  // namespace ROCKSDB_NAMESPACE
+
+#ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+extern "C" {
+void RegisterCustomObjects(int argc, char** argv);
+}
+#else
+void RegisterCustomObjects(int /*argc*/, char** /*argv*/) {}
+#endif  // !ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
+
+int main(int argc, char** argv) {
+  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
+  ::testing::InitGoogleTest(&argc, argv);
+  RegisterCustomObjects(argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+#else
+#include <stdio.h>
+
+int main(int /*argc*/, char** /*argv*/) {
+  fprintf(stderr,
+          "SKIPPED as CompactionService is not supported in ROCKSDB_LITE\n");
+  return 0;
+}
+
+#endif  // ROCKSDB_LITE
@@ -8,7 +8,24 @@

 #include <algorithm>

+#include "rocksdb/utilities/customizable_util.h"
+#include "rocksdb/utilities/object_registry.h"
+#include "rocksdb/utilities/options_type.h"
+
 namespace ROCKSDB_NAMESPACE {
+static std::unordered_map<std::string, OptionTypeInfo>
+    sst_fixed_prefix_type_info = {
+#ifndef ROCKSDB_LITE
+        {"length",
+         {0, OptionType::kSizeT, OptionVerificationType::kNormal,
+          OptionTypeFlags::kNone}},
+#endif  // ROCKSDB_LITE
+};
+
+SstPartitionerFixedPrefixFactory::SstPartitionerFixedPrefixFactory(size_t len)
+    : len_(len) {
+  RegisterOptions("Length", &len_, &sst_fixed_prefix_type_info);
+}

 PartitionerResult SstPartitionerFixedPrefix::ShouldPartition(
    const PartitionerRequest& request) {
@@ -41,4 +58,33 @@ std::shared_ptr<SstPartitionerFactory> NewSstPartitionerFixedPrefixFactory(
  return std::make_shared<SstPartitionerFixedPrefixFactory>(prefix_len);
 }

+#ifndef ROCKSDB_LITE
+namespace {
+static int RegisterSstPartitionerFactories(ObjectLibrary& library,
+                                           const std::string& /*arg*/) {
+  library.Register<SstPartitionerFactory>(
+      SstPartitionerFixedPrefixFactory::kClassName(),
+      [](const std::string& /*uri*/,
+         std::unique_ptr<SstPartitionerFactory>* guard,
+         std::string* /* errmsg */) {
+        guard->reset(new SstPartitionerFixedPrefixFactory(0));
+        return guard->get();
+      });
+  return 1;
+}
+}  // namespace
+#endif  // ROCKSDB_LITE
+
+Status SstPartitionerFactory::CreateFromString(
+    const ConfigOptions& options, const std::string& value,
+    std::shared_ptr<SstPartitionerFactory>* result) {
+#ifndef ROCKSDB_LITE
+  static std::once_flag once;
+  std::call_once(once, [&]() {
+    RegisterSstPartitionerFactories(*(ObjectLibrary::Default().get()), "");
+  });
+#endif  // ROCKSDB_LITE
+  return LoadSharedObject<SstPartitionerFactory>(options, value, nullptr,
+                                                 result);
+}
 }  // namespace ROCKSDB_NAMESPACE
--- a/Show More
+++ b/Show More