Fix Git Codex Review invocation

Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14726

Add SstFileReader::ParseTableIteratorKey() so callers of NewTableIterator() have a public way to decode raw table keys without duplicating RocksDB internal-key layout. The implementation delegates to the existing public ParsedEntryInfo parser using the reader comparator.

Reviewed By: pdillinger

Differential Revision: D104584393

fbshipit-source-id: 98e21c4d6676fbba69e533376b3da67539dd8fad

.clang-tidy

@@ -0,0 +1,86 @@
+# When making changes, verify the output of:
+#   clang-tidy -list-checks
+---
+Checks: "-*,\
+  bugprone-argument-comment,\
+  bugprone-dangling-handle,\
+  bugprone-fold-init-type,\
+  bugprone-forward-declaration-namespace,\
+  bugprone-forwarding-reference-overload,\
+  bugprone-shadow,\
+  bugprone-sizeof-*,\
+  bugprone-string-constructor,\
+  bugprone-undefined-memory-manipulation,\
+  bugprone-unused-return-value,\
+  bugprone-use-after-move,\
+  cert-env33-c,\
+  cert-err58-cpp,\
+  cert-msc30-c,\
+  cert-msc50-cpp,\
+  clang-analyzer-*,\
+  clang-diagnostic-*,\
+  -clang-diagnostic-missing-designated-field-initializers,\
+  concurrency-mt-unsafe,\
+  cppcoreguidelines-avoid-non-const-global-variables,\
+  cppcoreguidelines-missing-std-forward,\
+  cppcoreguidelines-pro-type-member-init,\
+  cppcoreguidelines-special-member-functions,\
+  cppcoreguidelines-virtual-class-destructor,\
+  google-build-using-namespace,\
+  google-explicit-constructor,\
+  google-readability-avoid-underscore-in-googletest-name,\
+  misc-definitions-in-headers,\
+  misc-redundant-expression,\
+  modernize-make-shared,\
+  modernize-use-emplace,\
+  modernize-use-noexcept,\
+  modernize-use-override,\
+  modernize-use-using,\
+  performance-faster-string-find,\
+  performance-for-range-copy,\
+  performance-implicit-conversion-in-loop,\
+  performance-inefficient-algorithm,\
+  performance-inefficient-string-concatenation,\
+  performance-inefficient-vector-operation,\
+  performance-move-const-arg,\
+  performance-move-constructor-init,\
+  performance-no-automatic-move,\
+  performance-no-int-to-ptr,\
+  performance-noexcept-move-constructor,\
+  performance-noexcept-swap,\
+  performance-trivially-destructible,\
+  performance-type-promotion-in-math-fn,\
+  performance-unnecessary-copy-initialization,\
+  performance-unnecessary-value-param,\
+  readability-braces-around-statements,\
+  readability-duplicate-include,\
+  readability-isolate-declaration,\
+  readability-operators-representation,\
+  readability-redundant-string-init"
+
+WarningsAsErrors: "bugprone-use-after-move"
+
+CheckOptions:
+- key: bugprone-easily-swappable-parameters.MinimumLength
+  value: 4
+- key: cppcoreguidelines-avoid-non-const-global-variables.AllowThreadLocal
+  value: true
+- key: cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor
+  value: true
+- key: cppcoreguidelines-special-member-functions.AllowImplicitlyDeletedCopyOrMove
+  value: true
+- key: modernize-use-using.IgnoreExternC
+  value: true
+- key: performance-move-const-arg.CheckTriviallyCopyableMove
+  value: false
+- key: performance-unnecessary-value-param.AllowedTypes
+  value: '[Pp]ointer$;[Pp]tr$;[Rr]ef(erence)?$'
+- key: performance-unnecessary-copy-initialization.AllowedTypes
+  value: '[Pp]ointer$;[Pp]tr$;[Rr]ef(erence)?$'
+- key: readability-operators-representation.BinaryOperators
+  value: '&&;&=;&;|;~;!;!=;||;|=;^;^='
+- key: readability-redundant-string-init.StringNames
+  value: '::std::basic_string'
+- key: readability-named-parameter.InsertPlainNamesInForwardDecls
+  value: true
+...

.github/actions/build-folly/action.yml

@@ -1,7 +1,26 @@
 name: build-folly
+description: Build folly and dependencies (skipped if cache hit)
+inputs:
+  cache-hit:
+    description: Whether the folly cache was hit
+    required: true
 runs:
   using: composite
   steps:
   - name: Build folly and dependencies
-    run: make build_folly
+    if: ${{ inputs.cache-hit != 'true' }}
+    run: |
+      clean_path=()
+      IFS=: read -ra path_entries <<< "$PATH"
+      for entry in "${path_entries[@]}"; do
+        if [[ "$entry" != "/usr/lib/ccache" ]]; then
+          clean_path+=("$entry")
+        fi
+      done
+      export PATH="$(IFS=:; echo "${clean_path[*]}")"
+      make build_folly
+    shell: bash
+  - name: Skip folly build (using cached version)
+    if: ${{ inputs.cache-hit == 'true' }}
+    run: echo "Folly build skipped - using cached version"
     shell: bash

.github/actions/cache-folly/action.yml

@@ -0,0 +1,33 @@
+name: cache-folly
+description: Cache folly build to speed up CI
+outputs:
+  cache-hit:
+    description: Whether the cache was hit
+    value: ${{ steps.cache-folly-build.outputs.cache-hit }}
+runs:
+  using: composite
+  steps:
+  - name: Extract FOLLY_MK_HASH
+    id: extract-folly-hash
+    shell: bash
+    run: |
+      FOLLY_MK_HASH=$(md5sum folly.mk | cut -d' ' -f1)
+      echo "hash=$FOLLY_MK_HASH" >> $GITHUB_OUTPUT
+  - name: Extract FOLLY_INSTALL_DIR
+    id: extract-folly-install-dir
+    shell: bash
+    run: |
+      FOLLY_INSTALL_DIR=$(cd third-party/folly && python3 build/fbcode_builder/getdeps.py show-inst-dir)
+      echo "dir=$(echo $FOLLY_INSTALL_DIR | sed 's|installed/folly|installed|')" >> $GITHUB_OUTPUT
+  - name: Cache folly build
+    id: cache-folly-build
+    uses: actions/cache@v4
+    with:
+      # Cache the folly build directory
+      path: ${{ steps.extract-folly-install-dir.outputs.dir }}
+      # Key is based on:
+      # - OS and architecture
+      # - The docker image, which may not always be specified/known
+      # - Hash of folly.mk, which includes the folly repository commit hash
+      # NOTE: this is still only intended for DEBUG folly builds
+      key: folly-build-${{ runner.os }}-${{ runner.arch }}-${{ github.job_container.image }}-${{ steps.extract-folly-hash.outputs.hash }}-${{ env.PORTABLE == '1' && 'portable' || 'native' }}

.github/actions/cache-getdeps-downloads/action.yml

@@ -0,0 +1,21 @@
+name: cache-getdeps-downloads
+description: Cache getdeps downloads to avoid unreliable mirrors and speed up builds
+outputs:
+  cache-hit:
+    description: Whether the cache was hit
+    value: ${{ steps.cache-downloads.outputs.cache-hit }}
+runs:
+  using: composite
+  steps:
+  - name: Cache getdeps downloads
+    id: cache-downloads
+    uses: actions/cache@v4
+    with:
+      # Use a fixed path that we control - folly.mk will sync with getdeps downloads dir
+      path: /tmp/rocksdb-getdeps-cache
+      # Use a rolling cache key - the cache accumulates downloads over time
+      # The key includes a weekly timestamp to ensure periodic refresh
+      key: getdeps-downloads-${{ runner.os }}-${{ runner.arch }}-week-${{ github.run_id }}
+      restore-keys: |
+        getdeps-downloads-${{ runner.os }}-${{ runner.arch }}-week-
+        getdeps-downloads-${{ runner.os }}-${{ runner.arch }}-

.github/actions/install-maven/action.yml

@@ -4,8 +4,8 @@ runs:
   steps:
   - name: Install Maven
     run: |
-      wget --no-check-certificate https://dlcdn.apache.org/maven/maven-3/3.9.6/binaries/apache-maven-3.9.6-bin.tar.gz
-      tar zxf apache-maven-3.9.6-bin.tar.gz
-      echo "export M2_HOME=$(pwd)/apache-maven-3.9.6" >> $GITHUB_ENV
-      echo "$(pwd)/apache-maven-3.9.6/bin" >> $GITHUB_PATH
+      wget --no-check-certificate https://archive.apache.org/dist/maven/maven-3/3.9.11/binaries/apache-maven-3.9.11-bin.tar.gz
+      tar zxf apache-maven-3.9.11-bin.tar.gz
+      echo "export M2_HOME=$(pwd)/apache-maven-3.9.11" >> $GITHUB_ENV
+      echo "$(pwd)/apache-maven-3.9.11/bin" >> $GITHUB_PATH
     shell: bash

.github/actions/pre-steps/action.yml

@@ -2,6 +2,9 @@ name: pre-steps
 runs:
   using: composite
   steps:
+  - name: Install lld linker for faster builds
+    run: apt-get update -y && apt-get install -y lld 2>/dev/null || true
+    shell: bash
   - name: Setup Environment Variables
     run: |-
       echo "GTEST_THROW_ON_FAILURE=0" >> "$GITHUB_ENV"

.github/actions/setup-ccache/action.yml

@@ -0,0 +1,54 @@
+name: setup-ccache
+description: Setup ccache for faster C++ compilation caching
+inputs:
+  cache-key-prefix:
+    description: Unique prefix for the cache key (e.g., 'build-linux')
+    required: true
+  portable:
+    description: Set PORTABLE=1 to disable -march=native (set to "false" for jobs linking pre-built Folly)
+    required: false
+    default: "true"
+runs:
+  using: composite
+  steps:
+    - name: Set ccache environment variables
+      run: |
+        echo "CCACHE_DIR=${{ github.workspace }}/.ccache" >> $GITHUB_ENV
+        echo "CCACHE_BASEDIR=${{ github.workspace }}" >> $GITHUB_ENV
+        echo "CCACHE_NOHASHDIR=true" >> $GITHUB_ENV
+        echo "CCACHE_COMPILERCHECK=content" >> $GITHUB_ENV
+        echo "CCACHE_SLOPPINESS=clang_index_store,file_stat_matches,include_file_ctime,include_file_mtime,ivfsoverlay,pch_defines,modules,system_headers,time_macros" >> $GITHUB_ENV
+        echo "CCACHE_MAXSIZE=4G" >> $GITHUB_ENV
+        if [ "${{ inputs.portable }}" = "true" ]; then
+          echo "PORTABLE=1" >> $GITHUB_ENV
+        fi
+      shell: bash
+    - name: Restore ccache
+      uses: actions/cache@v4
+      with:
+        path: ${{ github.workspace }}/.ccache
+        key: ccache-${{ inputs.cache-key-prefix }}-${{ github.head_ref || github.ref }}-${{ github.sha }}
+        restore-keys: |-
+          ccache-${{ inputs.cache-key-prefix }}-${{ github.head_ref || github.ref }}-
+          ccache-${{ inputs.cache-key-prefix }}-refs/heads/main-
+    - name: Install ccache
+      run: |
+        if [ "$RUNNER_OS" = "macOS" ]; then
+          which ccache || brew install ccache
+        else
+          which ccache || (apt-get update && apt-get install -y ccache)
+        fi
+      shell: bash
+    - name: Add ccache to PATH
+      run: |
+        if [ "$RUNNER_OS" = "macOS" ]; then
+          echo "$(brew --prefix ccache)/libexec" >> $GITHUB_PATH
+        else
+          echo "/usr/lib/ccache" >> $GITHUB_PATH
+        fi
+      shell: bash
+    - name: Zero ccache stats and set build marker
+      run: |
+        ccache -z
+        touch "$CCACHE_DIR/.build_marker"
+      shell: bash

.github/actions/setup-folly/action.yml

@@ -3,5 +3,9 @@ runs:
   using: composite
   steps:
   - name: Checkout folly sources
-    run: make checkout_folly
+    run: |
+      make checkout_folly
+    shell: bash
+  - name: Install patchelf and libaio
+    run: apt-get update -y && apt-get install -y patchelf libaio-dev
     shell: bash

.github/actions/teardown-ccache/action.yml

@@ -0,0 +1,15 @@
+name: teardown-ccache
+description: Trim stale ccache entries and print stats
+runs:
+  using: composite
+  steps:
+    - name: Trim and print ccache stats
+      run: |
+        if [ -z "$CCACHE_DIR" ]; then
+          echo "teardown-ccache: CCACHE_DIR not set, skipping (setup-ccache may not have run)"
+          exit 0
+        fi
+        .github/scripts/ccache-trim.sh || true
+        ccache -s || echo "teardown-ccache: ccache not found, skipping stats"
+      if: always()
+      shell: bash

.github/actions/windows-build-steps/action.yml

@@ -1,9 +1,31 @@
 name: windows-build-steps
+inputs:
+  suite-run:
+    description: Comma-separated list of test suites to run (empty to skip C++ tests)
+    required: false
+    default: arena_test,db_basic_test,db_test,db_test2,db_merge_operand_test,bloom_test,c_test,coding_test,crc32c_test,dynamic_bloom_test,env_basic_test,env_test,hash_test,random_test
+  run-java:
+    description: Whether to run Java tests
+    required: false
+    default: "true"
 runs:
   using: composite
   steps:
   - name: Add msbuild to PATH
     uses: microsoft/setup-msbuild@v1.3.1
+  - name: ccache
+    uses: hendrikmuhs/ccache-action@v1.2
+    with:
+      max-size: "10GB"
+      key: ccache-windows-${{ github.workflow }}
+      restore-keys: |
+        ccache-windows-
+  - name: Configure ccache
+    shell: pwsh
+    run: |
+      ccache --set-config=base_dir=C:\a\rocksdb\rocksdb
+      ccache --set-config=hash_dir=false
+      ccache --set-config=compiler_check=content
   - name: Custom steps
     env:
       THIRDPARTY_HOME: ${{ github.workspace }}/thirdparty
@@ -11,9 +33,9 @@ runs:
       CMAKE_BIN: C:/Program Files/CMake/bin/cmake.exe
       CTEST_BIN: C:/Program Files/CMake/bin/ctest.exe
       JAVA_HOME: C:/Program Files/BellSoft/LibericaJDK-8
-      SNAPPY_HOME: ${{ github.workspace }}/thirdparty/snappy-1.1.8
-      SNAPPY_INCLUDE: ${{ github.workspace }}/thirdparty/snappy-1.1.8;${{ github.workspace }}/thirdparty/snappy-1.1.8/build
-      SNAPPY_LIB_DEBUG: ${{ github.workspace }}/thirdparty/snappy-1.1.8/build/Debug/snappy.lib
+      SNAPPY_HOME: ${{ github.workspace }}/thirdparty/snappy-1.2.2
+      SNAPPY_INCLUDE: ${{ github.workspace }}/thirdparty/snappy-1.2.2;${{ github.workspace }}/thirdparty/snappy-1.2.2/build
+      SNAPPY_LIB_DEBUG: ${{ github.workspace }}/thirdparty/snappy-1.2.2/build/Debug/snappy.lib
     run: |-
       # NOTE: if ... Exit $LASTEXITCODE lines needed to exit and report failure
       echo ===================== Install Dependencies =====================
@@ -22,14 +44,14 @@ runs:
       mkdir $Env:THIRDPARTY_HOME
       cd $Env:THIRDPARTY_HOME
       echo "Building Snappy dependency..."
-      curl -Lo snappy-1.1.8.zip https://github.com/google/snappy/archive/refs/tags/1.1.8.zip
+      curl -Lo snappy-1.2.2.zip https://github.com/google/snappy/archive/refs/tags/1.2.2.zip
       if(!$?) { Exit $LASTEXITCODE }
-      unzip -q snappy-1.1.8.zip
+      unzip -q snappy-1.2.2.zip
       if(!$?) { Exit $LASTEXITCODE }
-      cd snappy-1.1.8
+      cd snappy-1.2.2
       mkdir build
       cd build
-      & cmake -G "$Env:CMAKE_GENERATOR" ..
+      & cmake -G "$Env:CMAKE_GENERATOR" .. -DSNAPPY_BUILD_TESTS=OFF -DSNAPPY_BUILD_BENCHMARKS=OFF
       if(!$?) { Exit $LASTEXITCODE }
       msbuild Snappy.sln -maxCpuCount -property:Configuration=Debug -property:Platform=x64
       if(!$?) { Exit $LASTEXITCODE }
@@ -38,17 +60,32 @@ runs:
       $env:Path = $env:JAVA_HOME + ";" + $env:Path
       mkdir build
       cd build
-      & cmake -G "$Env:CMAKE_GENERATOR" -DCMAKE_BUILD_TYPE=Debug -DOPTDBG=1 -DPORTABLE="$Env:CMAKE_PORTABLE" -DSNAPPY=1 -DJNI=1 ..
+      & cmake -G "$Env:CMAKE_GENERATOR" -DCMAKE_BUILD_TYPE=Debug -DWIN_CI=1 -DPORTABLE="$Env:CMAKE_PORTABLE" -DSNAPPY=1 -DXPRESS=1 -DJNI=1 ..
       if(!$?) { Exit $LASTEXITCODE }
       cd ..
       echo "Building with VS version: $Env:CMAKE_GENERATOR"
-      msbuild build/rocksdb.sln -maxCpuCount -property:Configuration=Debug -property:Platform=x64
+      # use more parallel processes than the number of processes available, as most of the compile command would be cache hit
+      msbuild build/rocksdb.sln /m:32 /p:LinkIncremental=false -property:Configuration=Debug -property:Platform=x64
       if(!$?) { Exit $LASTEXITCODE }
       echo ========================= Test RocksDB =========================
-      build_tools\run_ci_db_test.ps1 -SuiteRun arena_test,db_basic_test,db_test,db_test2,db_merge_operand_test,bloom_test,c_test,coding_test,crc32c_test,dynamic_bloom_test,env_basic_test,env_test,hash_test,random_test -Concurrency 16
-      if(!$?) { Exit $LASTEXITCODE }
-      echo ======================== Test RocksJava ========================
-      cd build\java
-      & ctest -C Debug -j 16
-      if(!$?) { Exit $LASTEXITCODE }
+      $suiteRun = "${{ inputs.suite-run }}"
+      if ($suiteRun -ne "") {
+        $suiteArray = $suiteRun -split ','
+        build_tools\run_ci_db_test.ps1 -SuiteRun $suiteArray -Concurrency 16
+        if(!$?) { Exit $LASTEXITCODE }
+      } else {
+        echo "Skipping C++ tests (suite-run is empty)"
+      }
+      if ("${{ inputs.run-java }}" -eq "true") {
+        echo ======================== Test RocksJava ========================
+        cd build\java
+        & ctest -C Debug -j 16
+        if(!$?) { Exit $LASTEXITCODE }
+      } else {
+        echo "Skipping Java tests"
+      }
     shell: pwsh
+  - name: Show ccache stats
+    shell: pwsh
+    run: |
+      ccache --show-stats -v

.github/scripts/build-ai-review-comment.js

@@ -0,0 +1,27 @@
+// Shared markdown builder for AI review comment bodies.
+//
+// Usage:
+//   const build = require('./build-ai-review-comment.js');
+//   return build({ icon, headerTitle, triggerLine, responseBody, footerLines
+//   });
+
+module.exports = function buildAiReviewComment(
+    {icon, headerTitle, triggerLine, responseBody, footerLines}) {
+  return [
+    `## ${icon} ${headerTitle}`,
+    '',
+    triggerLine,
+    '',
+    '---',
+    '',
+    responseBody,
+    '',
+    '---',
+    '',
+    '<details>',
+    '<summary>ℹ️ About this response</summary>',
+    '',
+    ...footerLines,
+    '</details>',
+  ].join('\n');
+};

.github/scripts/ccache-trim.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+# Trim ccache to keep only entries accessed during the current build.
+#
+# Usage: 
+#   1. Before build: touch "$CCACHE_DIR/.build_marker"
+#   2. Run build (ccache updates mtime on hits, creates new files for misses)
+#   3. After build: .github/scripts/ccache-trim.sh
+#
+# This removes cache files not accessed during the build (stale entries from
+# previous commits). Only intended for CI where each run builds one commit.
+# Do NOT use on local builds where multiple worktrees may share the cache.
+
+set -e
+
+CCACHE_DIR="${CCACHE_DIR:?CCACHE_DIR must be set}"
+MARKER="$CCACHE_DIR/.build_marker"
+
+if [ ! -f "$MARKER" ]; then
+    echo "ccache-trim: No .build_marker found, skipping (was the marker created before build?)"
+    exit 0
+fi
+
+# Count files before cleanup
+before=$(find "$CCACHE_DIR" -type f \( -name '*R' -o -name '*M' \) | wc -l)
+
+# Delete cache files (results and manifests) older than the marker
+find "$CCACHE_DIR" -type f \( -name '*R' -o -name '*M' \) ! -newer "$MARKER" -delete
+
+# Clean up empty directories
+find "$CCACHE_DIR" -mindepth 2 -type d -empty -delete 2>/dev/null || true
+
+# Recalculate size counters
+ccache -c 2>/dev/null || true
+
+after=$(find "$CCACHE_DIR" -type f \( -name '*R' -o -name '*M' \) | wc -l)
+echo "ccache-trim: $before -> $after cache files (removed $((before - after)) stale entries)"
+
+# Clean up marker
+rm -f "$MARKER"

.github/scripts/compute-test-shard.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+# Compute test shard for parallel CI execution.
+# Distributes tests round-robin across N shards for balanced load.
+# Outputs ROCKSDBTESTS_SUBSET — the list of test binaries for this shard.
+# The Makefile uses this to build and run only the assigned tests.
+#
+# Usage: compute-test-shard.sh <shard_index> <num_shards>
+
+set -euo pipefail
+
+shard=${1:?Usage: compute-test-shard.sh <shard_index> <num_shards>}
+nshards=${2:?Usage: compute-test-shard.sh <shard_index> <num_shards>}
+
+# Get sorted test list (db_test first since it's the heaviest, then alpha)
+make -s list_all_tests 2>/dev/null | tr ' ' '\n' | grep '_test$' | sort -u > /tmp/sorted.txt
+(echo db_test; grep -v '^db_test$' /tmp/sorted.txt) > /tmp/all_tests.txt
+
+total=$(wc -l < /tmp/all_tests.txt)
+
+# Round-robin: assign test i to shard (i % nshards).
+# This spreads heavy tests (which are scattered alphabetically) evenly.
+awk -v s="$shard" -v n="$nshards" 'NR > 0 && (NR - 1) % n == s' /tmp/all_tests.txt > /tmp/include.txt
+
+included=$(wc -l < /tmp/include.txt)
+first=$(head -1 /tmp/include.txt)
+last=$(tail -1 /tmp/include.txt)
+
+# Output space-separated list for ROCKSDBTESTS_SUBSET
+subset=$(tr '\n' ' ' < /tmp/include.txt)
+echo "subset=${subset}" >> "$GITHUB_OUTPUT"
+
+echo "Shard $shard/$nshards: $included tests (round-robin), first=$first last=$last (total $total)"

.github/scripts/parse-claude-review.js

@@ -0,0 +1,118 @@
+// Parse Claude Code execution log and produce a markdown review comment.
+//
+// Usage from actions/github-script:
+//   const parse = require('./.github/scripts/parse-claude-review.js');
+//   const markdown = parse({ executionFile, conclusion, meta });
+//
+// Parameters:
+//   executionFile - path to the JSON execution log from claude-code-base-action
+//   conclusion    - 'success' or 'failure' from the action output
+//   meta          - { trigger, autoMode, headSha, reviewer, isQuery, isPartial
+//   }
+
+const fs = require('fs');
+const buildComment = require('./build-ai-review-comment.js');
+
+module.exports = function parseClaude({executionFile, conclusion, meta}) {
+  function getTriggerLine() {
+    if (meta.trigger !== 'auto') {
+      return `*Requested by @${meta.reviewer}*`;
+    }
+    const shortSha = meta.headSha ? meta.headSha.substring(0, 7) : 'unknown';
+    if (meta.autoMode === 'early') {
+      return `*Auto-triggered after CI reached the early-review threshold — reviewing commit ${
+          shortSha}*`;
+    }
+    return `*Auto-triggered after CI passed — reviewing commit ${shortSha}*`;
+  }
+
+  let responseBody = '';
+
+  try {
+    const executionLog = JSON.parse(fs.readFileSync(executionFile, 'utf8'));
+
+    if (!Array.isArray(executionLog)) {
+      throw new Error('Expected array format from claude-code-base-action');
+    }
+
+    const resultMessage = executionLog.find(m => m.type === 'result');
+
+    // Helper: extract the last substantial assistant text from the log.
+    // Used as a fallback when Claude ran out of turns and the recovery
+    // session also failed to produce a result.
+    function getLastAssistantText(log, minLength = 200) {
+      for (let i = log.length - 1; i >= 0; i--) {
+        const m = log[i];
+        if (m.type !== 'assistant') continue;
+        const content = m.message && m.message.content;
+        if (!Array.isArray(content)) continue;
+        for (let j = content.length - 1; j >= 0; j--) {
+          if (content[j].type === 'text' && content[j].text &&
+              content[j].text.trim().length >= minLength) {
+            const text = content[j].text.trim();
+            // Truncate to avoid enormous PR comments
+            return text.length > 50000 ? text.substring(0, 50000) +
+                    '\n\n*[Truncated — full output in execution log artifact]*' :
+                                         text;
+          }
+        }
+      }
+      return null;
+    }
+
+    if (!resultMessage) {
+      responseBody = '⚠️ No result message found in execution log.';
+    } else if (resultMessage.subtype === 'success' && resultMessage.result) {
+      responseBody = resultMessage.result;
+    } else if (resultMessage.is_error || resultMessage.subtype === 'error') {
+      const errorInfo =
+          resultMessage.result || resultMessage.error || 'Unknown error';
+      responseBody = `❌ **Claude encountered an error:**\n\n${errorInfo}`;
+    } else if (resultMessage.subtype === 'error_max_turns') {
+      // The workflow runs a recovery session when this happens, so this
+      // branch is typically only hit if recovery wasn't attempted (e.g.,
+      // no findings file was written). Extract what we can.
+      const partial = getLastAssistantText(executionLog);
+      if (partial) {
+        responseBody =
+            `⚠️ **Review incomplete — Claude hit the turn limit.**\n\nBelow is the last partial output. You can request a fresh review with \`/claude-review\`.\n\n---\n\n${
+                partial}`;
+      } else {
+        responseBody =
+            '⚠️ **Review incomplete — Claude hit the turn limit before producing output.** You can request a fresh review with `/claude-review`.';
+      }
+    } else if (resultMessage.result) {
+      responseBody = `⚠️ **Completed with status: ${
+          resultMessage.subtype}**\n\n${resultMessage.result}`;
+    } else {
+      responseBody = '⚠️ Claude completed but produced no output.';
+    }
+  } catch (error) {
+    responseBody = `❌ Error parsing Claude response: ${error.message}`;
+  }
+
+  const isPartial = !!meta.isPartial;
+  const icon = isPartial ? '🟡' : (conclusion === 'success' ? '✅' : '⚠️');
+  const headerTitle = meta.isQuery ? 'Claude Response' : 'Claude Code Review';
+  const triggerLine = getTriggerLine();
+
+  return buildComment({
+    icon,
+    headerTitle,
+    triggerLine,
+    responseBody,
+    footerLines: [
+      'Generated by [Claude Code](https://github.com/anthropics/claude-code-action).',
+      'Review methodology: `claude_md/code_review.md`',
+      '',
+      '**Limitations:**',
+      '- Claude may miss context from files not in the diff',
+      '- Large PRs may be truncated',
+      '- Always apply human judgment to AI suggestions',
+      '',
+      '**Commands:**',
+      '- `/claude-review [context]` — Request a code review',
+      '- `/claude-query <question>` — Ask about the PR or codebase',
+    ],
+  });
+};

.github/scripts/parse-codex-review.js

@@ -0,0 +1,98 @@
+// Parse Codex review artifacts and produce a markdown review comment.
+//
+// Usage from actions/github-script:
+//   const parse = require('./.github/scripts/parse-codex-review.js');
+//   const markdown = parse({ responseFile, recoveryFile, findingsFile, logFile,
+//   exitCode, meta });
+//
+// Parameters:
+//   responseFile - path to Codex final response output
+//   recoveryFile - path to recovery output formatted from review-findings.md
+//   findingsFile - path to incremental findings file written during review
+//   logFile      - path to Codex stdout/stderr log
+//   exitCode     - Codex process exit code
+//   meta         - { trigger, autoMode, headSha, reviewer, isQuery, isPartial }
+
+const fs = require('fs');
+const buildComment = require('./build-ai-review-comment.js');
+
+module.exports = function parseCodex(
+    {responseFile, recoveryFile, findingsFile, logFile, exitCode, meta}) {
+  function getTriggerLine() {
+    if (meta.trigger !== 'auto') {
+      return `*Requested by @${meta.reviewer}*`;
+    }
+    const shortSha = meta.headSha ? meta.headSha.substring(0, 7) : 'unknown';
+    if (meta.autoMode === 'early') {
+      return `*Auto-triggered after CI reached the early-review threshold — reviewing commit ${
+          shortSha}*`;
+    }
+    return `*Auto-triggered after CI passed — reviewing commit ${shortSha}*`;
+  }
+
+  function readIfPresent(path) {
+    if (!path || !fs.existsSync(path)) {
+      return '';
+    }
+    const text = fs.readFileSync(path, 'utf8').trim();
+    return text;
+  }
+
+  function tailFile(path, maxChars = 12000) {
+    const text = readIfPresent(path);
+    if (!text) {
+      return '';
+    }
+    if (text.length <= maxChars) {
+      return text;
+    }
+    return text.slice(text.length - maxChars);
+  }
+
+  let responseBody = '';
+  const recovered = readIfPresent(recoveryFile);
+  const direct = readIfPresent(responseFile);
+  const findings = readIfPresent(findingsFile);
+
+  if (recovered) {
+    responseBody = recovered;
+  } else if (direct) {
+    responseBody = direct;
+  } else if (findings) {
+    responseBody =
+        '⚠️ **Review incomplete — Codex did not produce a final response.**\n\n' +
+        'Below are the incremental findings recovered from `review-findings.md`.\n\n---\n\n' +
+        findings;
+  } else {
+    const logTail = tailFile(logFile);
+    responseBody = logTail ?
+        `❌ **Codex review failed before producing findings.**\n\n\`\`\`\n${
+            logTail}\n\`\`\`` :
+        '❌ Codex review failed before producing any output.';
+  }
+
+  const isPartial = !!meta.isPartial;
+  const code = Number.parseInt(exitCode || '1', 10);
+  const icon = isPartial ? '🟡' : (code === 0 ? '✅' : '⚠️');
+  const triggerLine = getTriggerLine();
+
+  return buildComment({
+    icon,
+    headerTitle: meta.isQuery ? 'Codex Response' : 'Codex Code Review',
+    triggerLine,
+    responseBody,
+    footerLines: [
+      'Generated by Codex CLI.',
+      'Review methodology: `claude_md/code_review.md`',
+      '',
+      '**Limitations:**',
+      '- Codex may miss context from files not in the diff',
+      '- Large PRs may be truncated',
+      '- Always apply human judgment to AI suggestions',
+      '',
+      '**Commands:**',
+      '- `/codex-review [context]` — Request a code review',
+      '- `/codex-query <question>` — Ask about the PR or codebase',
+    ],
+  });
+};

.github/scripts/post-pr-comment.js

@@ -0,0 +1,204 @@
+// Shared PR comment posting utility.
+// Used by both clang-tidy-comment.yml and claude-review-comment.yml.
+//
+// Usage from actions/github-script:
+//   const post = require('./.github/scripts/post-pr-comment.js');
+//   await post({ github, context, core, prNumber, body, marker });
+//
+// Parameters:
+//   github   - octokit instance from actions/github-script
+//   context  - GitHub Actions context
+//   core     - @actions/core for logging
+//   prNumber - PR number to comment on
+//   body     - comment body (markdown string)
+//   marker   - HTML comment marker for dedup (e.g. '<!-- claude-review -->')
+//              If an existing comment with this marker is found, it is updated.
+//              If not found, a new comment is created.
+//   legacyMarkers - optional list of legacy markers that should be migrated by
+//              being considered part of the same comment family.
+//   prunePrefix - optional marker prefix whose older comments should be
+//                 superseded. If obsoleteTitle is set, older comments are
+//                 collapsed instead of deleted.
+//   preserveLatest - optional count of active comments to keep when
+//                    prunePrefix is set.
+//   obsoleteMarker - optional HTML marker used to detect already-obsolete
+//                    comments.
+//   obsoleteTitle - optional heading to use when collapsing superseded
+//                   comments into a details block.
+
+module.exports = async function postPrComment({
+  github,
+  context,
+  core,
+  prNumber,
+  body,
+  marker,
+  legacyMarkers = [],
+  prunePrefix = '',
+  preserveLatest = 0,
+  obsoleteMarker = '',
+  obsoleteTitle = '',
+}) {
+  if (!prNumber || !body) {
+    core.warning('Missing prNumber or body; skipping comment.');
+    return;
+  }
+
+  const owner = context.repo.owner;
+  const repo = context.repo.repo;
+
+  // Ensure marker is embedded in the body
+  const markedBody = body.includes(marker) ? body : `${marker}\n${body}`;
+
+  async function listComments() {
+    return await github.paginate(github.rest.issues.listComments, {
+      owner,
+      repo,
+      issue_number: prNumber,
+      per_page: 100,
+    });
+  }
+
+  function commentActivityTime(comment) {
+    const timestamp =
+        Date.parse(comment.updated_at || comment.created_at || '');
+    return Number.isNaN(timestamp) ? 0 : timestamp;
+  }
+
+  function commentSortDescending(left, right) {
+    const timeDelta = commentActivityTime(right) - commentActivityTime(left);
+    if (timeDelta !== 0) {
+      return timeDelta;
+    }
+    return Number(right.id || 0) - Number(left.id || 0);
+  }
+
+  function isObsoleteComment(comment) {
+    return !!obsoleteMarker && typeof comment.body === 'string' &&
+        comment.body.includes(obsoleteMarker);
+  }
+
+  function buildObsoleteBody(comment) {
+    const originalBody =
+        typeof comment.body === 'string' && comment.body.trim() ?
+        comment.body :
+        '*No original review body preserved.*';
+    const title = obsoleteTitle || 'AI Review - OBSOLETE';
+    return `${obsoleteMarker}\n## ${
+        title}\n\n<details>\n<summary>Superseded by a newer AI review. Expand to see the original review.</summary>\n\n${
+        originalBody}\n\n</details>`;
+  }
+
+  async function deleteCommentIfPresent(comment, reason) {
+    try {
+      await github.rest.issues.deleteComment({
+        owner,
+        repo,
+        comment_id: comment.id,
+      });
+      core.info(`${reason} ${comment.id}`);
+    } catch (error) {
+      if (error.status === 404) {
+        core.info(`Comment ${comment.id} was already deleted by another run.`);
+        return;
+      }
+      throw error;
+    }
+  }
+
+  async function supersedeCommentIfPresent(comment, reason) {
+    if (!obsoleteTitle) {
+      await deleteCommentIfPresent(comment, reason);
+      return;
+    }
+    if (isObsoleteComment(comment)) {
+      return;
+    }
+    try {
+      await github.rest.issues.updateComment({
+        owner,
+        repo,
+        comment_id: comment.id,
+        body: buildObsoleteBody(comment),
+      });
+      core.info(`${reason} ${comment.id}`);
+    } catch (error) {
+      if (error.status === 404) {
+        core.info(`Comment ${comment.id} was already deleted by another run.`);
+        return;
+      }
+      throw error;
+    }
+  }
+
+  let comments = await listComments();
+  const existing = comments.find(
+      comment =>
+          typeof comment.body === 'string' && comment.body.includes(marker));
+  let currentCommentId = null;
+
+  if (existing) {
+    try {
+      const response = await github.rest.issues.updateComment({
+        owner,
+        repo,
+        comment_id: existing.id,
+        body: markedBody,
+      });
+      currentCommentId = existing.id;
+      core.info(`Updated existing comment ${existing.id}`);
+    } catch (error) {
+      if (error.status !== 404) {
+        throw error;
+      }
+      core.info(
+          `Comment ${existing.id} disappeared before update; ` +
+          'creating a fresh comment instead.');
+    }
+  }
+
+  if (!currentCommentId) {
+    const response = await github.rest.issues.createComment({
+      owner,
+      repo,
+      issue_number: prNumber,
+      body: markedBody,
+    });
+    currentCommentId = response.data.id;
+    core.info('Created new PR comment');
+  }
+
+  if (prunePrefix || legacyMarkers.length > 0) {
+    comments = await listComments();
+    const relatedComments = comments.filter(
+        comment => comment.id !== currentCommentId &&
+            typeof comment.body === 'string' &&
+            ((prunePrefix && comment.body.includes(prunePrefix)) ||
+             legacyMarkers.some(
+                 legacyMarker => comment.body.includes(legacyMarker))));
+    const activeRelatedComments =
+        comments
+            .filter(
+                comment => typeof comment.body === 'string' &&
+                    !isObsoleteComment(comment) &&
+                    (comment.id === currentCommentId ||
+                     relatedComments.some(
+                         relatedComment => relatedComment.id === comment.id)))
+            .sort(commentSortDescending);
+
+    const keep =
+        new Set(activeRelatedComments.slice(0, Math.max(preserveLatest, 1))
+                    .map(comment => comment.id));
+
+    const supersedeCandidates = obsoleteTitle ?
+        activeRelatedComments.filter(comment => !keep.has(comment.id)) :
+        relatedComments.filter(comment => !keep.has(comment.id));
+
+    for (const comment of supersedeCandidates) {
+      if (keep.has(comment.id)) {
+        continue;
+      }
+      await supersedeCommentIfPresent(comment, 'Superseded old AI review');
+    }
+  }
+};

.github/scripts/post-pr-comment.test.js

@@ -0,0 +1,347 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const postPrComment = require('./post-pr-comment.js');
+
+const OBSOLETE_MARKER = '<!-- claude-review-obsolete -->';
+const OBSOLETE_TITLE = 'Claude Code Review - OBSOLETE';
+
+function makeComment(id, body, createdAt, updatedAt) {
+  return {
+    id,
+    body,
+    created_at: createdAt,
+    updated_at: updatedAt || createdAt,
+  };
+}
+
+function createHarness(initialComments, options = {}) {
+  let comments = initialComments.map(comment => ({...comment}));
+  let nextCommentId = options.nextCommentId || 1000;
+  let paginateCount = 0;
+
+  const calls = {
+    update: [],
+    create: [],
+    delete: [],
+  };
+
+  const github = {
+    paginate: async () => {
+      paginateCount++;
+      if (options.onPaginate) {
+        const updated = options.onPaginate({
+          paginateCount,
+          comments: comments.map(comment => ({...comment})),
+        });
+        if (updated) {
+          comments = updated.map(comment => ({...comment}));
+        }
+      }
+      return comments.map(comment => ({...comment}));
+    },
+    rest: {
+      issues: {
+        listComments: () => {
+          throw new Error('listComments should only be used through paginate');
+        },
+        updateComment: async ({comment_id, body}) => {
+          calls.update.push({comment_id, body});
+          const error =
+              options.updateErrors && options.updateErrors[comment_id];
+          if (error) {
+            throw error;
+          }
+          const index =
+              comments.findIndex(comment => comment.id === comment_id);
+          if (index === -1) {
+            const notFound = new Error(`Comment ${comment_id} not found`);
+            notFound.status = 404;
+            throw notFound;
+          }
+          const updated = {
+            ...comments[index],
+            body,
+            updated_at: options.updateTimestamp || '2026-04-24T00:00:00Z',
+          };
+          comments[index] = updated;
+          return {data: {...updated}};
+        },
+        createComment: async ({issue_number, body}) => {
+          calls.create.push({issue_number, body});
+          const created = makeComment(
+              nextCommentId++, body,
+              options.createTimestamp || '2026-04-24T00:00:00Z');
+          comments.push(created);
+          return {data: {id: created.id}};
+        },
+        deleteComment: async ({comment_id}) => {
+          calls.delete.push({comment_id});
+          const error =
+              options.deleteErrors && options.deleteErrors[comment_id];
+          if (error) {
+            throw error;
+          }
+          comments = comments.filter(comment => comment.id !== comment_id);
+        },
+      },
+    },
+  };
+
+  return {
+    github,
+    calls,
+    getComments: () => comments.map(comment => ({...comment})),
+  };
+}
+
+function createCore() {
+  return {
+    info: () => {},
+    warning: () => {},
+  };
+}
+
+function escapeRegExp(value) {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+function assertObsoleteComment(comment, originalBody) {
+  assert.ok(comment);
+  assert.match(comment.body, new RegExp(escapeRegExp(OBSOLETE_MARKER)));
+  assert.match(comment.body, new RegExp(`## ${escapeRegExp(OBSOLETE_TITLE)}`));
+  assert.match(comment.body, /<details>/);
+  assert.match(comment.body, /Superseded by a newer AI review/);
+  assert.match(comment.body, new RegExp(escapeRegExp(originalBody)));
+}
+
+const context = {
+  repo: {
+    owner: 'facebook',
+    repo: 'rocksdb',
+  },
+};
+
+test(
+    'creates a fresh review comment and supersedes legacy comments',
+    async () => {
+      const harness = createHarness(
+          [
+            makeComment(
+                1, '<!-- claude-review-auto -->\nold legacy', 'not-a-date'),
+            makeComment(
+                2, '<!-- claude-review-auto -->\nnew legacy',
+                '2026-04-21T00:00:00Z'),
+          ],
+          {
+            updateTimestamp: '2026-04-24T00:00:00Z',
+          });
+
+      await postPrComment({
+        github: harness.github,
+        context,
+        core: createCore(),
+        prNumber: 14659,
+        body: 'review body',
+        marker: '<!-- claude-review-auto-run-500 -->',
+        legacyMarkers: ['<!-- claude-review-auto -->'],
+        prunePrefix: '<!-- claude-review-auto-',
+        preserveLatest: 1,
+        obsoleteMarker: OBSOLETE_MARKER,
+        obsoleteTitle: OBSOLETE_TITLE,
+      });
+
+      assert.equal(harness.calls.create.length, 1);
+      assert.deepEqual(
+          harness.calls.update.map(call => call.comment_id), [2, 1]);
+      assert.equal(harness.calls.delete.length, 0);
+
+      const comments = harness.getComments();
+      assert.equal(comments.length, 3);
+      assert.match(
+          comments.find(comment => comment.id === 1000).body,
+          /<!-- claude-review-auto-run-500 -->/);
+      assertObsoleteComment(
+          comments.find(comment => comment.id === 2),
+          '<!-- claude-review-auto -->\nnew legacy');
+      assertObsoleteComment(
+          comments.find(comment => comment.id === 1),
+          '<!-- claude-review-auto -->\nold legacy');
+    });
+
+test(
+    'updates an exact-match comment and supersedes leftover legacy comments',
+    async () => {
+      const harness = createHarness(
+          [
+            makeComment(
+                3, '<!-- claude-review-auto-abcdef0 -->\ncurrent body',
+                '2026-04-24T00:00:00Z'),
+            makeComment(
+                4, '<!-- claude-review-auto -->\nlegacy body',
+                '2026-04-20T00:00:00Z'),
+          ],
+          {
+            updateTimestamp: '2026-04-24T01:00:00Z',
+          });
+
+      await postPrComment({
+        github: harness.github,
+        context,
+        core: createCore(),
+        prNumber: 14659,
+        body: 'refreshed body',
+        marker: '<!-- claude-review-auto-abcdef0 -->',
+        legacyMarkers: ['<!-- claude-review-auto -->'],
+        prunePrefix: '<!-- claude-review-auto-',
+        preserveLatest: 1,
+        obsoleteMarker: OBSOLETE_MARKER,
+        obsoleteTitle: OBSOLETE_TITLE,
+      });
+
+      assert.deepEqual(
+          harness.calls.update.map(call => call.comment_id), [3, 4]);
+      assert.equal(harness.calls.create.length, 0);
+      assert.equal(harness.calls.delete.length, 0);
+
+      const comments = harness.getComments();
+      assert.match(
+          comments.find(comment => comment.id === 3).body,
+          /<!-- claude-review-auto-abcdef0 -->\nrefreshed body/);
+      assertObsoleteComment(
+          comments.find(comment => comment.id === 4),
+          '<!-- claude-review-auto -->\nlegacy body');
+    });
+
+test(
+    'creates a new comment if the target disappears before update',
+    async () => {
+      const missing = new Error('gone');
+      missing.status = 404;
+      const harness = createHarness(
+          [
+            makeComment(
+                10, '<!-- claude-review-auto-abcdef0 -->\nold body',
+                '2026-04-20T00:00:00Z'),
+          ],
+          {
+            updateErrors: {
+              10: missing,
+            },
+          });
+
+      await postPrComment({
+        github: harness.github,
+        context,
+        core: createCore(),
+        prNumber: 14659,
+        body: 'replacement body',
+        marker: '<!-- claude-review-auto-abcdef0 -->',
+      });
+
+      assert.equal(harness.calls.update.length, 1);
+      assert.equal(harness.calls.create.length, 1);
+      assert.match(
+          harness.calls.create[0].body, /<!-- claude-review-auto-abcdef0 -->/);
+    });
+
+test(
+    'ignores 404 when superseding a comment already deleted by another run',
+    async () => {
+      const missing = new Error('gone');
+      missing.status = 404;
+      const harness = createHarness(
+          [
+            makeComment(
+                20, '<!-- claude-review-auto-oldest -->\noldest',
+                '2026-04-20T00:00:00Z'),
+            makeComment(
+                21, '<!-- claude-review-auto-newer -->\nnewer',
+                '2026-04-21T00:00:00Z'),
+          ],
+          {
+            nextCommentId: 30,
+            createTimestamp: '2026-04-24T00:00:00Z',
+            deleteErrors: {
+              20: missing,
+            },
+          });
+
+      await postPrComment({
+        github: harness.github,
+        context,
+        core: createCore(),
+        prNumber: 14659,
+        body: 'fresh body',
+        marker: '<!-- claude-review-auto-latest -->',
+        prunePrefix: '<!-- claude-review-auto-',
+        preserveLatest: 1,
+        obsoleteMarker: OBSOLETE_MARKER,
+        obsoleteTitle: OBSOLETE_TITLE,
+      });
+
+      assert.equal(harness.calls.create.length, 1);
+      assert.equal(harness.calls.delete.length, 0);
+      assert.deepEqual(
+          harness.calls.update.map(call => call.comment_id), [21, 20]);
+
+      const comments = harness.getComments();
+      assertObsoleteComment(
+          comments.find(comment => comment.id === 21),
+          '<!-- claude-review-auto-newer -->\nnewer');
+    });
+
+test(
+    'supersedes the current review when a newer concurrent one appears',
+    async () => {
+      const harness = createHarness(
+          [
+            makeComment(
+                40, '<!-- claude-review-auto-current -->\ncurrent',
+                '2026-04-20T00:00:00Z'),
+            makeComment(
+                41, '<!-- claude-review-auto-older -->\nolder',
+                '2026-04-19T00:00:00Z'),
+          ],
+          {
+            updateTimestamp: '2026-04-24T00:00:00Z',
+            onPaginate: ({paginateCount, comments}) => {
+              if (paginateCount !== 2) {
+                return comments;
+              }
+              return comments.concat([
+                makeComment(
+                    42, '<!-- claude-review-auto-newer -->\nnewer',
+                    '2026-04-25T00:00:00Z'),
+              ]);
+            },
+          });
+
+      await postPrComment({
+        github: harness.github,
+        context,
+        core: createCore(),
+        prNumber: 14659,
+        body: 'updated current body',
+        marker: '<!-- claude-review-auto-current -->',
+        prunePrefix: '<!-- claude-review-auto-',
+        preserveLatest: 1,
+        obsoleteMarker: OBSOLETE_MARKER,
+        obsoleteTitle: OBSOLETE_TITLE,
+      });
+
+      assert.deepEqual(
+          harness.calls.update.map(call => call.comment_id), [40, 40, 41]);
+      assert.equal(harness.calls.delete.length, 0);
+
+      const comments = harness.getComments();
+      assert.match(
+          comments.find(comment => comment.id === 42).body,
+          /<!-- claude-review-auto-newer -->\nnewer/);
+      assertObsoleteComment(
+          comments.find(comment => comment.id === 40),
+          '<!-- claude-review-auto-current -->\nupdated current body');
+      assertObsoleteComment(
+          comments.find(comment => comment.id === 41),
+          '<!-- claude-review-auto-older -->\nolder');
+    });

.github/workflows/ai-review-comment.yml

@@ -0,0 +1,185 @@
+# Shared comment-posting workflow for AI reviews.
+
+name: AI Review Comment
+
+on:
+  workflow_call:
+    inputs:
+      provider:
+        description: Provider key, for example "claude" or "codex"
+        required: true
+        type: string
+      result_artifact_name:
+        description: Artifact name produced by the analysis workflow
+        required: true
+        type: string
+      comment_file:
+        description: Markdown comment file produced by the analysis workflow
+        required: true
+        type: string
+
+permissions:
+  pull-requests: write
+  issues: write
+
+jobs:
+  comment:
+    if: github.event.workflow_run.conclusion == 'success'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout scripts
+        uses: actions/checkout@v4
+        with:
+          sparse-checkout: .github/scripts
+          sparse-checkout-cone-mode: true
+
+      - name: Download review artifact
+        id: download
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ inputs.result_artifact_name }}
+          run-id: ${{ github.event.workflow_run.id }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+        continue-on-error: true
+
+      - name: Post or update PR comment
+        if: steps.download.outcome == 'success'
+        env:
+          PROVIDER: ${{ inputs.provider }}
+          COMMENT_FILE: ${{ inputs.comment_file }}
+          RUN_ID: ${{ github.event.workflow_run.id }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            if (!fs.existsSync(process.env.COMMENT_FILE) ||
+                !fs.existsSync('pr_number.txt')) {
+              core.info('No review results found; skipping.');
+              return;
+            }
+
+            const post = require('./.github/scripts/post-pr-comment.js');
+            const provider = process.env.PROVIDER;
+            const providerTitle = provider === 'codex' ? 'Codex' : 'Claude';
+            const body = fs.readFileSync(process.env.COMMENT_FILE, 'utf8');
+            const prNumber = parseInt(
+              fs.readFileSync('pr_number.txt', 'utf8').trim(),
+              10
+            );
+            const trigger = fs.existsSync('trigger_type.txt') ?
+              fs.readFileSync('trigger_type.txt', 'utf8').trim() :
+              'auto';
+            const headSha = fs.existsSync('head_sha.txt') ?
+              fs.readFileSync('head_sha.txt', 'utf8').trim() :
+              '';
+            const shortSha = headSha ? headSha.substring(0, 7) : '';
+            const runId = process.env.RUN_ID;
+
+            let marker = '';
+            let legacyMarkers = [];
+            let prunePrefix = '';
+            let preserveLatest = 0;
+            let obsoleteMarker = '';
+            let obsoleteTitle = '';
+
+            if (trigger === 'auto') {
+              if (!shortSha) {
+                core.warning(
+                  'Missing head_sha.txt for auto review; skipping comment.'
+                );
+                return;
+              }
+              marker = `<!-- ${provider}-review-auto-run-${runId} -->`;
+              legacyMarkers = [`<!-- ${provider}-review-auto -->`];
+              prunePrefix = `<!-- ${provider}-review-auto-`;
+              preserveLatest = 1;
+              obsoleteMarker = `<!-- ${provider}-review-obsolete -->`;
+              obsoleteTitle = `${providerTitle} Code Review - OBSOLETE`;
+            } else {
+              marker = `<!-- ${provider}-review-manual-run-${runId} -->`;
+            }
+
+            await post({
+              github,
+              context,
+              core,
+              prNumber,
+              body,
+              marker,
+              legacyMarkers,
+              prunePrefix,
+              preserveLatest,
+              obsoleteMarker,
+              obsoleteTitle,
+            });
+
+      - name: Add reaction to trigger comment
+        if: steps.download.outcome == 'success'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            if (!fs.existsSync('trigger_type.txt')) return;
+            const trigger = fs.readFileSync('trigger_type.txt', 'utf8').trim();
+            if (trigger !== 'manual') return;
+            if (!fs.existsSync('comment_id.txt')) return;
+            const commentId = parseInt(
+              fs.readFileSync('comment_id.txt', 'utf8').trim(),
+              10
+            );
+            if (!commentId) return;
+
+            await github.rest.reactions.createForIssueComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              comment_id: commentId,
+              content: 'rocket'
+            });
+
+  failure-notice:
+    if: github.event.workflow_run.conclusion == 'failure'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download artifact for PR number
+        id: download
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ inputs.result_artifact_name }}
+          run-id: ${{ github.event.workflow_run.id }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+        continue-on-error: true
+
+      - name: React with failure
+        if: steps.download.outcome == 'success'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            if (!fs.existsSync('comment_id.txt')) return;
+            const commentId = parseInt(
+              fs.readFileSync('comment_id.txt', 'utf8').trim(),
+              10
+            );
+            if (!commentId) return;
+
+            await github.rest.reactions.createForIssueComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              comment_id: commentId,
+              content: 'confused'
+            });
+
+  unauthorized-notice:
+    runs-on: ubuntu-latest
+    if: >-
+      github.event.workflow_run.event == 'issue_comment' &&
+      github.event.workflow_run.conclusion == 'skipped'
+    steps:
+      - name: Log skipped unauthorized request
+        uses: actions/github-script@v7
+        with:
+          script: |
+            core.info(
+              'Analysis workflow was skipped, which usually means the ' +
+              'issue_comment requester was not in the authorized list.'
+            );

.github/workflows/clang-tidy-comment.yml

@@ -0,0 +1,51 @@
+name: Post clang-tidy PR comment
+on:
+  workflow_run:
+    workflows: ["clang-tidy"]
+    types: [completed]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  comment:
+    if: github.event.workflow_run.event == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout scripts
+      uses: actions/checkout@v4
+      with:
+        sparse-checkout: .github/scripts
+        sparse-checkout-cone-mode: true
+
+    - name: Download clang-tidy results
+      id: download
+      uses: actions/download-artifact@v4.1.3
+      with:
+        name: clang-tidy-result
+        run-id: ${{ github.event.workflow_run.id }}
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+      continue-on-error: true
+
+    - name: Post or update PR comment
+      if: steps.download.outcome == 'success'
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const fs = require('fs');
+          if (!fs.existsSync('clang-tidy-comment.md') || !fs.existsSync('pr_number.txt')) {
+            core.info('No clang-tidy results found; skipping.');
+            return;
+          }
+          const body = fs.readFileSync('clang-tidy-comment.md', 'utf8');
+          const prNumber = parseInt(fs.readFileSync('pr_number.txt', 'utf8').trim());
+          const post = require('./.github/scripts/post-pr-comment.js');
+
+          await post({
+            github,
+            context,
+            core,
+            prNumber,
+            body,
+            marker: '<!-- clang-tidy-bot -->',
+          });

.github/workflows/clang-tidy.yml

@@ -0,0 +1,74 @@
+name: clang-tidy
+on:
+  push:
+  pull_request:
+
+permissions: {}
+
+jobs:
+  clang-tidy:
+    if: github.repository_owner == 'facebook'
+    runs-on:
+      labels: 4-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
+    steps:
+    - uses: actions/checkout@v4.1.0
+      with:
+        fetch-depth: 2
+    - name: Mark workspace as safe for git
+      run: git config --global --add safe.directory $GITHUB_WORKSPACE
+    - name: Determine diff base
+      id: diff-base
+      run: |
+        if [ "${{ github.event_name }}" = "pull_request" ]; then
+          BASE="${{ github.event.pull_request.base.sha }}"
+          git fetch --depth=1 origin "$BASE"
+        else
+          BASE="${{ github.event.before }}"
+          if echo "$BASE" | grep -q '^0\{40\}$'; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            echo "New branch push; skipping clang-tidy."
+            exit 0
+          fi
+        fi
+        echo "ref=$BASE" >> "$GITHUB_OUTPUT"
+        echo "skip=false" >> "$GITHUB_OUTPUT"
+    - name: Install clang-tidy
+      if: steps.diff-base.outputs.skip != 'true'
+      run: apt-get update && apt-get install -y clang-tidy-21 && ln -sf /usr/bin/clang-tidy-21 /usr/local/bin/clang-tidy
+    - name: Generate compile_commands.json
+      if: steps.diff-base.outputs.skip != 'true'
+      run: |
+        mkdir build && cd build
+        cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
+              -DCMAKE_C_COMPILER=clang-21 \
+              -DCMAKE_CXX_COMPILER=clang++-21 ..
+        cd ..
+        ln -sf build/compile_commands.json compile_commands.json
+    - name: Run clang-tidy on changed files
+      id: clang-tidy
+      if: steps.diff-base.outputs.skip != 'true'
+      run: |
+        python3 tools/run_clang_tidy.py \
+          -j 4 \
+          --diff-base ${{ steps.diff-base.outputs.ref }} \
+          --github-annotations \
+          --github-step-summary \
+          --comment-output clang-tidy-comment.md
+      continue-on-error: true
+    - name: Save PR number
+      if: github.event_name == 'pull_request' && always()
+      run: echo "${{ github.event.pull_request.number }}" > pr_number.txt
+    - name: Upload clang-tidy results
+      if: always()
+      uses: actions/upload-artifact@v4.0.0
+      with:
+        name: clang-tidy-result
+        path: |
+          clang-tidy-comment.md
+          pr_number.txt
+        if-no-files-found: ignore
+    - name: Fail if clang-tidy found issues
+      if: steps.clang-tidy.outcome == 'failure'
+      run: exit 1

.github/workflows/claude-review-comment.yml

@@ -0,0 +1,25 @@
+# Claude Code Review — Comment Posting Workflow
+#
+# Thin wrapper around .github/workflows/ai-review-comment.yml so the provider
+# specific workflow name stays stable while the shared implementation lives in
+# one reusable workflow.
+
+name: Post Claude Review Comment
+
+on:
+  workflow_run:
+    workflows: ["Claude Code Review"]
+    types: [completed]
+
+permissions:
+  pull-requests: write
+  issues: write
+
+jobs:
+  review-comment:
+    uses: ./.github/workflows/ai-review-comment.yml
+    with:
+      provider: claude
+      result_artifact_name: claude-review-result
+      comment_file: claude-review-comment.md
+    secrets: inherit

.github/workflows/claude-review.yml

@@ -0,0 +1,69 @@
+# Claude Code Review — Analysis Workflow
+#
+# Thin wrapper around .github/workflows/ai-review-analysis.yml so provider
+# specific triggers and workflow_dispatch inputs stay stable while the shared
+# implementation lives in one reusable workflow.
+
+name: Claude Code Review
+
+on:
+  workflow_run:
+    workflows: ["facebook/rocksdb/pr-jobs"]
+    types: [completed]
+
+  # The early pull_request_target path is limited to same-repo PRs by the job
+  # condition below. Fork PRs skip this path and rely on workflow_run instead.
+  pull_request_target:
+    types: [opened, reopened, synchronize]
+
+  issue_comment:
+    types: [created]
+
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: PR number to review
+        required: true
+        type: number
+      model:
+        description: Claude model to use (defaults to latest Opus)
+        required: false
+        type: choice
+        options:
+          - claude-opus-4-6
+          - claude-sonnet-4-6
+        default: claude-opus-4-6
+      thinking_budget:
+        description: Override MAX_THINKING_TOKENS (blank = auto-classify, capped at 24000)
+        required: false
+        type: string
+        default: ""
+
+permissions:
+  contents: read
+  # The shared analysis workflow polls check state, inspects prior runs, and
+  # reads PR metadata. Keep those permissions read-only in the caller.
+  actions: read
+  checks: read
+  pull-requests: read
+
+jobs:
+  review:
+    if: >-
+      github.event_name != 'pull_request_target' ||
+      github.event.pull_request.head.repo.full_name == github.repository
+    uses: ./.github/workflows/ai-review-analysis.yml
+    with:
+      provider: claude
+      display_name: Claude
+      review_command: /claude-review
+      query_command: /claude-query
+      result_artifact_name: claude-review-result
+      comment_file: claude-review-comment.md
+      default_model: claude-opus-4-6
+      selected_model: ${{ github.event_name == 'workflow_dispatch' && inputs.model || '' }}
+      classifier_model: claude-sonnet-4-6
+      recovery_model: claude-sonnet-4-6
+      thinking_budget: ${{ github.event_name == 'workflow_dispatch' && inputs.thinking_budget || '' }}
+      dispatch_pr_number: ${{ github.event_name == 'workflow_dispatch' && inputs.pr_number || '' }}
+    secrets: inherit

.github/workflows/codex-review-comment.yml

@@ -0,0 +1,25 @@
+# Codex Code Review — Comment Posting Workflow
+#
+# Thin wrapper around .github/workflows/ai-review-comment.yml so the provider
+# specific workflow name stays stable while the shared implementation lives in
+# one reusable workflow.
+
+name: Post Codex Review Comment
+
+on:
+  workflow_run:
+    workflows: ["Codex Code Review"]
+    types: [completed]
+
+permissions:
+  pull-requests: write
+  issues: write
+
+jobs:
+  review-comment:
+    uses: ./.github/workflows/ai-review-comment.yml
+    with:
+      provider: codex
+      result_artifact_name: codex-review-result
+      comment_file: codex-review-comment.md
+    secrets: inherit

.github/workflows/codex-review.yml

@@ -0,0 +1,68 @@
+# Codex Code Review — Analysis Workflow
+#
+# Thin wrapper around .github/workflows/ai-review-analysis.yml so provider
+# specific triggers and workflow_dispatch inputs stay stable while the shared
+# implementation lives in one reusable workflow.
+
+name: Codex Code Review
+
+on:
+  workflow_run:
+    workflows: ["facebook/rocksdb/pr-jobs"]
+    types: [completed]
+
+  # The early pull_request_target path is limited to same-repo PRs by the job
+  # condition below. Fork PRs skip this path and rely on workflow_run instead.
+  pull_request_target:
+    types: [opened, reopened, synchronize]
+
+  issue_comment:
+    types: [created]
+
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: PR number to review
+        required: true
+        type: number
+      model:
+        description: Codex model to use
+        required: false
+        type: choice
+        options:
+          - gpt-5.5
+          - gpt-5.3-codex
+          - gpt-5.2-codex
+        default: gpt-5.5
+      thinking_budget:
+        description: Override MAX_THINKING_TOKENS (blank = auto-classify)
+        required: false
+        type: string
+        default: ""
+
+permissions:
+  contents: read
+  # The shared analysis workflow polls check state, inspects prior runs, and
+  # reads PR metadata. Keep those permissions read-only in the caller.
+  actions: read
+  checks: read
+  pull-requests: read
+
+jobs:
+  review:
+    if: >-
+      github.event_name != 'pull_request_target' ||
+      github.event.pull_request.head.repo.full_name == github.repository
+    uses: ./.github/workflows/ai-review-analysis.yml
+    with:
+      provider: codex
+      display_name: Codex
+      review_command: /codex-review
+      query_command: /codex-query
+      result_artifact_name: codex-review-result
+      comment_file: codex-review-comment.md
+      default_model: gpt-5.5
+      selected_model: ${{ github.event_name == 'workflow_dispatch' && inputs.model || '' }}
+      thinking_budget: ${{ github.event_name == 'workflow_dispatch' && inputs.thinking_budget || '' }}
+      dispatch_pr_number: ${{ github.event_name == 'workflow_dispatch' && inputs.pr_number || '' }}
+    secrets: inherit

.github/workflows/nightly.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
@@ -27,24 +27,12 @@ jobs:
         git config --global --add safe.directory /__w/rocksdb/rocksdb
         tools/check_format_compatible.sh
     - uses: "./.github/actions/post-steps"
-  build-linux-run-microbench:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - run: DEBUG_LEVEL=0 make -j32 run_microbench
-    - uses: "./.github/actions/post-steps"
   build-linux-non-shm:
     if: ${{ github.repository_owner == 'facebook' }}
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     env:
       TEST_TMPDIR: "/tmp/rocksdb_test_tmp"
@@ -53,34 +41,77 @@ jobs:
     - uses: "./.github/actions/pre-steps"
     - run: make V=1 -j32 check
     - uses: "./.github/actions/post-steps"
-  build-linux-clang-13-asan-ubsan-with-folly:
+  build-linux-clang-21-asan-ubsan-with-folly:
     if: ${{ github.repository_owner == 'facebook' }}
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
       options: --shm-size=16gb
     env:
-      CC: clang-13
-      CXX: clang++-13
+      CC: clang-21
+      CXX: clang++-21
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/cache-getdeps-downloads"
     - uses: "./.github/actions/setup-folly"
-    - uses: "./.github/actions/build-folly"
+    - name: Build folly and dependencies
+      run: |
+        clean_path=()
+        IFS=: read -ra path_entries <<< "$PATH"
+        for entry in "${path_entries[@]}"; do
+          if [[ "$entry" != "/usr/lib/ccache" ]]; then
+            clean_path+=("$entry")
+          fi
+        done
+        export PATH="$(IFS=:; echo "${clean_path[*]}")"
+        ccache_bin="$(command -v ccache || true)"
+        if [[ -n "$ccache_bin" && -x "$ccache_bin" ]]; then
+          mv "$ccache_bin" "${ccache_bin}.disabled"
+        fi
+        export CC=gcc
+        export CXX=g++
+        export USE_CCACHE=0
+        export CCACHE_DISABLE=1
+        make build_folly
+      shell: bash
     - run: LIB_MODE=static USE_CLANG=1 USE_FOLLY=1 COMPILE_WITH_UBSAN=1 COMPILE_WITH_ASAN=1 make -j32 check
     - uses: "./.github/actions/post-steps"
-  build-linux-valgrind:
+  build-linux-cmake-with-folly:
     if: ${{ github.repository_owner == 'facebook' }}
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: make V=1 -j32 valgrind_test
+    - uses: "./.github/actions/cache-getdeps-downloads"
+    - uses: "./.github/actions/setup-folly"
+    - uses: "./.github/actions/cache-folly"
+      id: cache-folly
+    - uses: "./.github/actions/build-folly"
+      with:
+        cache-hit: ${{ steps.cache-folly.outputs.cache-hit }}
+    - run: "(mkdir build && cd build && cmake -DUSE_FOLLY=1 -DWITH_GFLAGS=1 -DROCKSDB_BUILD_SHARED=0 .. && make VERBOSE=1 -j20 && ctest -j20)"
+    - uses: "./.github/actions/post-steps"
+  build-linux-release-with-folly:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 16-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/cache-getdeps-downloads"
+    - uses: "./.github/actions/setup-folly"
+    - run: "DEBUG_LEVEL=0 make -j20 build_folly"
+    - run: "USE_FOLLY=1 LIB_MODE=static DEBUG_LEVEL=0 V=1 make -j20 release"
+    - run: "(mkdir build && cd build && cmake -DUSE_FOLLY=1 -DWITH_GFLAGS=1 -DROCKSDB_BUILD_SHARED=0 -DCMAKE_BUILD_TYPE=Release .. && make VERBOSE=1 -j20 && ctest -j20)"
     - uses: "./.github/actions/post-steps"
   build-windows-vs2022-avx2:
     if: ${{ github.repository_owner == 'facebook' }}
@@ -91,15 +122,6 @@ jobs:
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/windows-build-steps"
-  build-windows-vs2022:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: windows-2022
-    env:
-      CMAKE_GENERATOR: Visual Studio 17 2022
-      CMAKE_PORTABLE: 1
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/windows-build-steps"
   build-linux-arm-test-full:
     if: ${{ github.repository_owner == 'facebook' }}
     runs-on:
@@ -110,3 +132,59 @@ jobs:
       - run: sudo apt-get update && sudo apt-get install -y build-essential libgflags-dev
       - run: make V=1 J=4 -j4 check
       - uses: "./.github/actions/post-steps"
+  build-linux-arm-crashtest:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 4-core-ubuntu-arm
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - run: sudo apt-get update && sudo apt-get install -y build-essential libgflags-dev libsnappy-dev zlib1g-dev libbz2-dev liblz4-dev libzstd-dev
+    - run: sudo mount -o remount,size=16G /dev/shm
+    - run: sudo dd bs=1048576 count=4096 if=/dev/zero of=/swapfile && sudo chmod 600 /swapfile && sudo mkswap /swapfile && sudo swapon /swapfile
+    - run: ulimit -S -n `ulimit -H -n` && make V=1 -j8 CRASH_TEST_EXT_ARGS='--duration=1800 --max_key=2500000' blackbox_crash_test_with_atomic_flush
+    - run: rm -rf /dev/shm/rocksdb.*
+    - run: ulimit -S -n `ulimit -H -n` && make V=1 -j8 CRASH_TEST_EXT_ARGS='--duration=1800 --max_key=2500000' blackbox_crash_test_with_multiops_wc_txn
+    - uses: "./.github/actions/post-steps"
+  build-examples:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 4-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - name: Build examples
+      run: make V=1 -j4 static_lib && cd examples && make V=1 -j4
+    - uses: "./.github/actions/post-steps"
+  build-fuzzers:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 4-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - name: Build rocksdb lib
+      run: CC=clang-21 CXX=clang++-21 USE_CLANG=1 make -j4 static_lib
+    - name: Build fuzzers
+      run: cd fuzz && make sst_file_writer_fuzzer db_fuzzer db_map_fuzzer
+    - uses: "./.github/actions/post-steps"
+  build-linux-cmake-with-folly-lite:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 16-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/cache-getdeps-downloads"
+    - uses: "./.github/actions/setup-folly"
+    - run: "(mkdir build && cd build && cmake -DUSE_FOLLY_LITE=1 -DWITH_GFLAGS=1 -DCMAKE_CXX_FLAGS=-DGLOG_USE_GLOG_EXPORT .. && make VERBOSE=1 -j20 && ctest -j20)"
+    - uses: "./.github/actions/post-steps"

.github/workflows/pr-jobs.yml

@@ -1,7 +1,18 @@
 name: facebook/rocksdb/pr-jobs
 on: [push, pull_request]
 permissions: {}
+env:
+  # Set to a job name to run only that job (on any repo), or leave empty for
+  # normal behavior (all jobs on facebook repo only).
+  ONLY_JOB: ''
 jobs:
+  config:
+    runs-on: ubuntu-latest
+    outputs:
+      only_job: ${{ steps.set.outputs.only_job }}
+    steps:
+    - id: set
+      run: echo "only_job=$ONLY_JOB" >> "$GITHUB_OUTPUT"
   # NOTE: multiple workflows would be recommended, but the current GHA UI in
   # PRs doesn't make it clear when there's an overall error with a workflow,
   # making it easy to overlook something broken. Grouping everything into one
@@ -19,6 +30,10 @@ jobs:
   # increasing the risk of misconfiguration, especially on forks that might
   # want to run with this GHA setup.
   #
+  # SELECTIVE JOB EXECUTION: Set the ONLY_JOB env var at the top of this file
+  # to a job name (e.g. "build-linux-clang-tidy") to run only that job,
+  # bypassing the repository owner check. Leave it empty for normal behavior.
+  #
   # DEBUGGING WITH SSH: Temporarily add this as a job step, either before the
   # step of interest without the "if:" line or after the failing step with the
   # "if:" line. Then use ssh command printed in CI output.
@@ -30,7 +45,8 @@ jobs:
 
   # ======================== Fast Initial Checks ====================== #
   check-format-and-targets:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'check-format-and-targets' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on: ubuntu-24.04
     steps:
     - uses: actions/checkout@v4.1.0
@@ -44,6 +60,10 @@ jobs:
       run: python -m pip install --upgrade pip
     - name: Install argparse
       run: pip install argparse
+    - name: Install clang-format
+      run: |
+        pip install https://files.pythonhosted.org/packages/fb/ac/3c04772acc0257f5730e83adb542b2603c1a62d1315010ab593a980af404/clang_format-21.1.2-py2.py3-none-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl
+        clang-format --version
     - name: Download clang-format-diff.py
       run: wget https://rocksdb-deps.s3.us-west-2.amazonaws.com/llvm/llvm-project/release/12.x/clang/tools/clang-format/clang-format-diff.py
     - name: Check format
@@ -52,29 +72,49 @@ jobs:
       run: make check-buck-targets
     - name: Simple source code checks
       run: make check-sources
+    - name: Validate GitHub Actions YAML
+      run: make check-workflow-yaml
+    - name: Sanity check check_format_compatible.sh
+      run: |-
+        export TEST_TMPDIR=/dev/shm/rocksdb
+        rm -rf /dev/shm/rocksdb
+        mkdir /dev/shm/rocksdb
+        git reset --hard
+        git config --global --add safe.directory /__w/rocksdb/rocksdb
+        SANITY_CHECK=1 LONG_TEST=1 tools/check_format_compatible.sh
   # ========================= Linux With Tests ======================== #
   build-linux:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: build-linux
     - run: make V=1 J=32 -j32 check
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-cmake-mingw:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-cmake-mingw' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: cmake-mingw
     - run: update-alternatives --set x86_64-w64-mingw32-g++ /usr/bin/x86_64-w64-mingw32-g++-posix
     - name: Build cmake-mingw
       run: |-
@@ -83,266 +123,224 @@ jobs:
         which java && java -version
         which javac && javac -version
         mkdir build && cd build && cmake -DJNI=1 -DWITH_GFLAGS=OFF .. -DCMAKE_C_COMPILER=x86_64-w64-mingw32-gcc -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-g++ -DCMAKE_SYSTEM_NAME=Windows && make -j4 rocksdb rocksdbjni
-    - uses: "./.github/actions/post-steps"
-  build-linux-cmake-with-folly:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    env:
-      CC: gcc-10
-      CXX: g++-10
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - uses: "./.github/actions/setup-folly"
-    - uses: "./.github/actions/build-folly"
-    - run: "(mkdir build && cd build && cmake -DUSE_FOLLY=1 -DWITH_GFLAGS=1 -DROCKSDB_BUILD_SHARED=0 .. && make V=1 -j20 && ctest -j20)"
-    - uses: "./.github/actions/post-steps"
-  build-linux-cmake-with-folly-lite-no-test:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    env:
-      CC: gcc-10
-      CXX: g++-10
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - uses: "./.github/actions/setup-folly"
-    - run: "(mkdir build && cd build && cmake -DUSE_FOLLY_LITE=1 -DWITH_GFLAGS=1 .. && make V=1 -j20)"
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-make-with-folly:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-make-with-folly' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
-      labels: 16-core-ubuntu
+      labels: 32-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
-    env:
-      CC: gcc-10
-      CXX: g++-10
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/cache-getdeps-downloads"
     - uses: "./.github/actions/setup-folly"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: make-with-folly
+    - uses: "./.github/actions/cache-folly"
+      id: cache-folly
     - uses: "./.github/actions/build-folly"
-    - run: USE_FOLLY=1 LIB_MODE=static V=1 make -j32 check
+      with:
+        cache-hit: ${{ steps.cache-folly.outputs.cache-hit }}
+    - run: USE_FOLLY=1 LIB_MODE=static V=1 make -j64 check
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-make-with-folly-lite-no-test:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-make-with-folly-lite-no-test' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
-    env:
-      CC: gcc-10
-      CXX: g++-10
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/cache-getdeps-downloads"
     - uses: "./.github/actions/setup-folly"
-    - run: USE_FOLLY_LITE=1 V=1 make -j32 all
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: make-folly-lite
+    - run: USE_FOLLY_LITE=1 EXTRA_CXXFLAGS=-DGLOG_USE_GLOG_EXPORT V=1 make -j32 all
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-cmake-with-folly-coroutines:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-cmake-with-folly-coroutines' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
-      labels: 16-core-ubuntu
+      labels: 32-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
-    env:
-      CC: gcc-10
-      CXX: g++-10
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/cache-getdeps-downloads"
     - uses: "./.github/actions/setup-folly"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: cmake-folly-coroutines
+    - uses: "./.github/actions/cache-folly"
+      id: cache-folly
     - uses: "./.github/actions/build-folly"
-    - run: "(mkdir build && cd build && cmake -DUSE_COROUTINES=1 -DWITH_GFLAGS=1 -DROCKSDB_BUILD_SHARED=0 .. && make V=1 -j20 && ctest -j20)"
+      with:
+        cache-hit: ${{ steps.cache-folly.outputs.cache-hit }}
+    - run: "(mkdir build && cd build && cmake -DUSE_COROUTINES=1 -DWITH_GFLAGS=1 -DROCKSDB_BUILD_SHARED=0 -DPORTABLE=ON .. && make VERBOSE=1 -j64 && ctest -j64)"
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
-  build-linux-cmake-with-benchmark:
-    if: ${{ github.repository_owner == 'facebook' }}
+  build-linux-cmake-with-benchmark-no-thread-status:
+    if: needs.config.outputs.only_job == 'build-linux-cmake-with-benchmark-no-thread-status' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 16-core-ubuntu
+    strategy:
+      fail-fast: false
+      matrix:
+        shard: [0, 1, 2, 3]
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: mkdir build && cd build && cmake -DWITH_GFLAGS=1 -DWITH_BENCHMARK=1 .. && make V=1 -j20 && ctest -j20
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: cmake-benchmark
+    - name: Build
+      run: mkdir build && cd build && cmake -DWITH_GFLAGS=1 -DWITH_BENCHMARK=1 -DPORTABLE=ON -DCMAKE_CXX_FLAGS=-DNROCKSDB_THREAD_STATUS .. && make VERBOSE=1 -j20
+    - name: Test shard ${{ matrix.shard }} of 4
+      run: cd build && ctest -j20 -I ${{ matrix.shard }},,4
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
+      with:
+        artifact-prefix: "${{ github.job }}-shard${{ matrix.shard }}"
   build-linux-encrypted_env-no_compression:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-encrypted_env-no_compression' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: encrypted-env-no-compression
     - run: ENCRYPTED_ENV=1 ROCKSDB_DISABLE_SNAPPY=1 ROCKSDB_DISABLE_ZLIB=1 ROCKSDB_DISABLE_BZIP=1 ROCKSDB_DISABLE_LZ4=1 ROCKSDB_DISABLE_ZSTD=1 make V=1 J=32 -j32 check
-    - run: "./sst_dump --help | grep -E -q 'Supported compression types: kNoCompression$' # Verify no compiled in compression\n"
+    - run: "./sst_dump --help | grep -E -q 'Supported built-in compression types: kNoCompression$' # Verify no compiled in compression\n"
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   # ======================== Linux No Test Runs ======================= #
   build-linux-release:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-release' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: release
     - run: make V=1 -j32 LIB_MODE=shared release
     - run: ls librocksdb.so
-    - run: "./db_stress --version"
+    - run: "./trace_analyzer --version" # A tool dependent on gflags that can run in release build
     - run: make clean
-    - run: make V=1 -j32 release
+    - run: USE_RTTI=1 make V=1 -j32 release
     - run: ls librocksdb.a
-    - run: "./db_stress --version"
+    - run: "./trace_analyzer --version"
     - run: make clean
     - run: apt-get remove -y libgflags-dev
     - run: make V=1 -j32 LIB_MODE=shared release
     - run: ls librocksdb.so
-    - run: if ./db_stress --version; then false; else true; fi
+    - run: if ./trace_analyzer --version; then false; else true; fi
     - run: make clean
-    - run: make V=1 -j32 release
+    - run: USE_RTTI=1 make V=1 -j32 release
     - run: ls librocksdb.a
-    - run: if ./db_stress --version; then false; else true; fi
-    - uses: "./.github/actions/post-steps"
-  build-linux-release-rtti:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 8-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - run: USE_RTTI=1 DEBUG_LEVEL=0 make V=1 -j16 static_lib tools db_bench
-    - run: "./db_stress --version"
-    - run: make clean
-    - run: apt-get remove -y libgflags-dev
-    - run: USE_RTTI=1 DEBUG_LEVEL=0 make V=1 -j16 static_lib tools db_bench
-    - run: if ./db_stress --version; then false; else true; fi
-  build-examples:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 4-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - name: Build examples
-      run: make V=1 -j4 static_lib && cd examples && make V=1 -j4
-    - uses: "./.github/actions/post-steps"
-  build-fuzzers:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 4-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - name: Build rocksdb lib
-      run: CC=clang-13 CXX=clang++-13 USE_CLANG=1 make -j4 static_lib
-    - name: Build fuzzers
-      run: cd fuzz && make sst_file_writer_fuzzer db_fuzzer db_map_fuzzer
-    - uses: "./.github/actions/post-steps"
-  build-linux-clang-no_test_run:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 8-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - run: CC=clang CXX=clang++ USE_CLANG=1 PORTABLE=1 make V=1 -j16 all
+    - run: if ./trace_analyzer --version; then false; else true; fi
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-clang-13-no_test_run:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-clang-13-no_test_run' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
-      labels: 16-core-ubuntu
+      labels: 8-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: CC=clang-13 CXX=clang++-13 USE_CLANG=1 make -j32 all microbench
-    - uses: "./.github/actions/post-steps"
-  build-linux-gcc-8-no_test_run:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - run: CC=gcc-8 CXX=g++-8 V=1 make -j32 all
-    - uses: "./.github/actions/post-steps"
-  build-linux-gcc-10-cxx20-no_test_run:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - run: CC=gcc-10 CXX=g++-10 V=1 ROCKSDB_CXX_STANDARD=c++20 make -j32 all
-    - uses: "./.github/actions/post-steps"
-  build-linux-gcc-11-no_test_run:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - run: LIB_MODE=static CC=gcc-11 CXX=g++-11 V=1 make -j32 all microbench
-    - uses: "./.github/actions/post-steps"
-  # ======================== Linux Other Checks ======================= #
-  build-linux-clang10-clang-analyze:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - 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
-    - uses: "./.github/actions/post-steps"
-    - name: compress test report
-      run: tar -cvzf scan_build_report.tar.gz scan_build_report
-      if: failure()
-    - uses: actions/upload-artifact@v4.0.0
+    - uses: "./.github/actions/setup-ccache"
       with:
-        name: scan-build-report
-        path: scan_build_report.tar.gz
+        cache-key-prefix: clang-13
+    # FIXME: get back to "all microbench" targets
+    - run: CC=clang-13 CXX=clang++-13 USE_CLANG=1 EXTRA_CXXFLAGS=-stdlib=libc++ EXTRA_LDFLAGS=-stdlib=libc++ make -j32 shared_lib
+    - run: make clean
+    # FIXME: get back to "release" target
+    - run: CC=clang-13 CXX=clang++-13 USE_CLANG=1 EXTRA_CXXFLAGS=-stdlib=libc++ EXTRA_LDFLAGS=-stdlib=libc++ DEBUG_LEVEL=0 make -j32 shared_lib
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
+    - uses: "./.github/actions/post-steps"
+  build-linux-clang-21-no_test_run:
+    if: needs.config.outputs.only_job == 'build-linux-clang-21-no_test_run' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on:
+      labels: 16-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: clang-21
+    - run: CC=clang-21 CXX=clang++-21 USE_CLANG=1 make -j32 all microbench
+    - run: make clean
+    - run: CC=clang-21 CXX=clang++-21 USE_CLANG=1 DEBUG_LEVEL=0 make -j32 release
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
+    - uses: "./.github/actions/post-steps"
+  build-linux-gcc-14-no_test_run:
+    if: needs.config.outputs.only_job == 'build-linux-gcc-14-no_test_run' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on:
+      labels: 16-core-ubuntu
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: gcc-14
+    - run: CC=gcc-14 CXX=g++-14 V=1 make -j32 all microbench
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
+    - uses: "./.github/actions/post-steps"
+
+  # ======================== Linux Other Checks ======================= #
+
   build-linux-unity-and-headers:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-unity-and-headers' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu
     container:
@@ -351,185 +349,256 @@ jobs:
     steps:
     - uses: actions/checkout@v4.1.0
     - run: apt-get update -y && apt-get install -y libgflags-dev
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: unity-headers
     - name: Unity build
       run: make V=1 -j8 unity_test
     - run: make V=1 -j8 -k check-headers
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-mini-crashtest:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-mini-crashtest' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - crash_test_target: blackbox_crash_test_with_atomic_flush
+          crash_duration: 480
+        - crash_test_target: blackbox_crash_test
+          crash_duration: 240
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: ulimit -S -n `ulimit -H -n` && make V=1 -j8 CRASH_TEST_EXT_ARGS='--duration=960 --max_key=2500000' blackbox_crash_test_with_atomic_flush
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: mini-crashtest
+    - run: ulimit -S -n `ulimit -H -n` && make V=1 -j8 CRASH_TEST_EXT_ARGS='--duration=${{ matrix.crash_duration }} --max_key=2500000' ${{ matrix.crash_test_target }}
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
+      with:
+        artifact-prefix: "${{ github.job }}-${{ matrix.crash_test_target }}"
   # ======================= Linux with Sanitizers ===================== #
-  build-linux-clang10-asan:
-    if: ${{ github.repository_owner == 'facebook' }}
+  build-linux-clang21-asan-ubsan:
+    if: needs.config.outputs.only_job == 'build-linux-clang21-asan-ubsan' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 32-core-ubuntu
+    strategy:
+      fail-fast: false
+      matrix:
+        shard: [0, 1, 2]
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: COMPILE_WITH_ASAN=1 CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: clang21-asan-ubsan
+    - run: COMPILE_WITH_ASAN=1 COMPILE_WITH_UBSAN=1 CC=clang-21 CXX=clang++-21 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j40 check
+      env:
+        CI_SHARD_INDEX: ${{ matrix.shard }}
+        CI_TOTAL_SHARDS: 3
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
-  build-linux-clang10-ubsan:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on:
-      labels: 16-core-ubuntu
-    container:
-      image: zjay437/rocksdb:0.6
-      options: --shm-size=16gb
-    steps:
-    - uses: actions/checkout@v4.1.0
-    - uses: "./.github/actions/pre-steps"
-    - run: COMPILE_WITH_UBSAN=1 CC=clang-10 CXX=clang++-10 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 ubsan_check
-    - uses: "./.github/actions/post-steps"
-  build-linux-clang13-mini-tsan:
-    if: ${{ github.repository_owner == 'facebook' }}
+      with:
+        artifact-prefix: "${{ github.job }}-shard${{ matrix.shard }}"
+  build-linux-clang21-mini-tsan:
+    if: needs.config.outputs.only_job == 'build-linux-clang21-mini-tsan' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 32-core-ubuntu
+    strategy:
+      fail-fast: false
+      matrix:
+        shard: [0, 1, 2]
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:24.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: COMPILE_WITH_TSAN=1 CC=clang-13 CXX=clang++-13 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: clang21-tsan
+    - run: COMPILE_WITH_TSAN=1 CC=clang-21 CXX=clang++-21 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check
+      env:
+        CI_SHARD_INDEX: ${{ matrix.shard }}
+        CI_TOTAL_SHARDS: 3
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
+      with:
+        artifact-prefix: "${{ github.job }}-shard${{ matrix.shard }}"
   build-linux-static_lib-alt_namespace-status_checked:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-static_lib-alt_namespace-status_checked' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 16-core-ubuntu
     container:
-      image: zjay437/rocksdb:0.6
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
-    - run: ASSERT_STATUS_CHECKED=1 TEST_UINT128_COMPAT=1 ROCKSDB_MODIFY_NPHASH=1 LIB_MODE=static OPT="-DROCKSDB_NAMESPACE=alternative_rocksdb_ns" make V=1 -j24 check
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: static-alt-namespace
+    - run: ASSERT_STATUS_CHECKED=1 TEST_UINT128_COMPAT=1 ROCKSDB_MODIFY_NPHASH=1 LIB_MODE=static OPT="-DROCKSDB_USE_STD_SEMAPHORES -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" make V=1 -j24 check
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   # ========================= MacOS build only ======================== #
   build-macos:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: macos-13
+    if: needs.config.outputs.only_job == 'build-macos' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on: macos-15-xlarge
     env:
       ROCKSDB_DISABLE_JEMALLOC: 1
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: maxim-lobanov/setup-xcode@v1.6.0
       with:
-        xcode-version: 14.3.1
+        xcode-version: 16.4.0
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: macos
     - uses: "./.github/actions/increase-max-open-files-on-macos"
     - uses: "./.github/actions/install-gflags-on-macos"
     - uses: "./.github/actions/pre-steps-macos"
     - name: Build
-      run: ulimit -S -n `ulimit -H -n` && make V=1 J=16 -j16 all
+      run: ulimit -S -n `ulimit -H -n` && make V=1 J=16 -j8 all
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   # ========================= MacOS with Tests ======================== #
   build-macos-cmake:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: macos-13
+    if: needs.config.outputs.only_job == 'build-macos-cmake' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on: macos-15-xlarge
     strategy:
       matrix:
-        run_even_tests: [true, false]
+        run_sharded_tests: [0, 1, 2, 3]
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: maxim-lobanov/setup-xcode@v1.6.0
       with:
-        xcode-version: 14.3.1
+        xcode-version: 16.4.0
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: macos-cmake
     - uses: "./.github/actions/increase-max-open-files-on-macos"
     - uses: "./.github/actions/install-gflags-on-macos"
     - uses: "./.github/actions/pre-steps-macos"
     - name: cmake generate project file
       run: ulimit -S -n `ulimit -H -n` && mkdir build && cd build && cmake -DWITH_GFLAGS=1 ..
     - name: Build tests
-      run: cd build && make V=1 -j16
-    - name: Run even tests
-      run: ulimit -S -n `ulimit -H -n` && cd build && ctest -j16 -I 0,,2
-      if: ${{ matrix.run_even_tests }}
-    - name: Run odd tests
-      run: ulimit -S -n `ulimit -H -n` && cd build && ctest -j16 -I 1,,2
-      if: ${{ ! matrix.run_even_tests  }}
+      run: cd build && make VERBOSE=1 -j8
+    - name: Run shard 0 out of 4 test shards
+      run: ulimit -S -n `ulimit -H -n` && cd build && ctest -j8 -I 0,,4
+      if: ${{ matrix.run_sharded_tests == 0 }}
+    - name: Run shard 1 out of 4 test shards
+      run: ulimit -S -n `ulimit -H -n` && cd build && ctest -j8 -I 1,,4
+      if: ${{ matrix.run_sharded_tests == 1 }}
+    - name: Run shard 2 out of 4 test shards
+      run: ulimit -S -n `ulimit -H -n` && cd build && ctest -j8 -I 2,,4
+      if: ${{ matrix.run_sharded_tests == 2 }}
+    - name: Run shard 3 out of 4 test shards
+      run: ulimit -S -n `ulimit -H -n` && cd build && ctest -j8 -I 3,,4
+      if: ${{ matrix.run_sharded_tests == 3 }}
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   # ======================== Windows with Tests ======================= #
   # NOTE: some windows jobs are in "nightly" to save resources
-  build-windows-vs2019:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: windows-2019
+  build-windows-vs2022:
+    if: needs.config.outputs.only_job == 'build-windows-vs2022' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on: windows-8-core
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - test_shard: db_test
+          suite_run: db_test
+          run_java: "false"
+        - test_shard: other
+          suite_run: arena_test,db_basic_test,db_test2,db_merge_operand_test,bloom_test,c_test,coding_test,crc32c_test,dynamic_bloom_test,env_basic_test,env_test,hash_test,random_test
+          run_java: "false"
+        - test_shard: java
+          suite_run: ""
+          run_java: "true"
     env:
-      CMAKE_GENERATOR: Visual Studio 16 2019
+      CMAKE_GENERATOR: Visual Studio 17 2022
       CMAKE_PORTABLE: 1
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/windows-build-steps"
+      with:
+        suite-run: ${{ matrix.suite_run }}
+        run-java: ${{ matrix.run_java }}
   # ============================ Java Jobs ============================ #
   build-linux-java:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-java' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu
     container:
-      image: evolvedbinary/rocksjava:centos6_x64-be
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
-    # The docker image is intentionally based on an OS that has an older GLIBC version.
-    # That GLIBC is incompatibile with GitHub's actions/checkout. Thus we implement a manual checkout step.
-    - name: Checkout
-      env:
-        GH_TOKEN: ${{ github.token }}
-      run: |
-        chown `whoami` . || true
-        git clone --no-checkout https://oath2:$GH_TOKEN@github.com/${{ github.repository }}.git .
-        git -c protocol.version=2 fetch --update-head-ok --no-tags --prune --no-recurse-submodules --depth=1 origin +${{ github.sha }}:${{ github.ref }}
-        git checkout --progress --force ${{ github.ref }}
-        git log -1 --format='%H'
+    - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: java
     - name: Set Java Environment
       run: |-
         echo "JAVA_HOME=${JAVA_HOME}"
         which java && java -version
         which javac && javac -version
     - name: Test RocksDBJava
-      run: scl enable devtoolset-7 'make V=1 J=8 -j8 jtest'
-    # NOTE: post-steps skipped because of compatibility issues with docker image
+      run: make V=1 J=8 -j8 jtest
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
   build-linux-java-static:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-java-static' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu
     container:
-      image: evolvedbinary/rocksjava:centos6_x64-be
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
       options: --shm-size=16gb
     steps:
-    # The docker image is intentionally based on an OS that has an older GLIBC version.
-    # That GLIBC is incompatibile with GitHub's actions/checkout. Thus we implement a manual checkout step.
-    - name: Checkout
-      env:
-        GH_TOKEN: ${{ github.token }}
-      run: |
-        chown `whoami` . || true
-        git clone --no-checkout https://oath2:$GH_TOKEN@github.com/${{ github.repository }}.git .
-        git -c protocol.version=2 fetch --update-head-ok --no-tags --prune --no-recurse-submodules --depth=1 origin +${{ github.sha }}:${{ github.ref }}
-        git checkout --progress --force ${{ github.ref }}
-        git log -1 --format='%H'
+    - uses: actions/checkout@v4.1.0
     - uses: "./.github/actions/pre-steps"
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: java-static
     - name: Set Java Environment
       run: |-
         echo "JAVA_HOME=${JAVA_HOME}"
         which java && java -version
         which javac && javac -version
     - name: Build RocksDBJava Static Library
-      run: scl enable devtoolset-7 'make V=1 J=8 -j8 rocksdbjavastatic'
-    # NOTE: post-steps skipped because of compatibility issues with docker image
+      run: make V=1 J=8 -j8 rocksdbjavastatic
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
   build-macos-java:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: macos-13
+    if: needs.config.outputs.only_job == 'build-macos-java' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on: macos-15-xlarge
     env:
       JAVA_HOME: "/Library/Java/JavaVirtualMachines/liberica-jdk-8.jdk/Contents/Home"
       ROCKSDB_DISABLE_JEMALLOC: 1
@@ -537,7 +606,10 @@ jobs:
     - uses: actions/checkout@v4.1.0
     - uses: maxim-lobanov/setup-xcode@v1.6.0
       with:
-        xcode-version: 14.3.1
+        xcode-version: 16.4.0
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: macos-java
     - uses: "./.github/actions/increase-max-open-files-on-macos"
     - uses: "./.github/actions/install-gflags-on-macos"
     - uses: "./.github/actions/install-jdk8-on-macos"
@@ -549,17 +621,23 @@ jobs:
         which javac && javac -version
     - name: Test RocksDBJava
       run: make V=1 J=16 -j16 jtest
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-macos-java-static:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: macos-13
+    if: needs.config.outputs.only_job == 'build-macos-java-static' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on: macos-15-xlarge
     env:
       JAVA_HOME: "/Library/Java/JavaVirtualMachines/liberica-jdk-8.jdk/Contents/Home"
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: maxim-lobanov/setup-xcode@v1.6.0
       with:
-        xcode-version: 14.3.1
+        xcode-version: 16.4.0
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: macos-java-static
     - uses: "./.github/actions/increase-max-open-files-on-macos"
     - uses: "./.github/actions/install-gflags-on-macos"
     - uses: "./.github/actions/install-jdk8-on-macos"
@@ -571,17 +649,23 @@ jobs:
         which javac && javac -version
     - name: Build RocksDBJava x86 and ARM Static Libraries
       run: make V=1 J=16 -j16 rocksdbjavastaticosx
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-macos-java-static-universal:
-    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: macos-13
+    if: needs.config.outputs.only_job == 'build-macos-java-static-universal' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
+    runs-on: macos-15-xlarge
     env:
       JAVA_HOME: "/Library/Java/JavaVirtualMachines/liberica-jdk-8.jdk/Contents/Home"
     steps:
     - uses: actions/checkout@v4.1.0
     - uses: maxim-lobanov/setup-xcode@v1.6.0
       with:
-        xcode-version: 14.3.1
+        xcode-version: 16.4.0
+    - uses: "./.github/actions/setup-ccache"
+      with:
+        cache-key-prefix: macos-java-static-universal
     - uses: "./.github/actions/increase-max-open-files-on-macos"
     - uses: "./.github/actions/install-gflags-on-macos"
     - uses: "./.github/actions/install-jdk8-on-macos"
@@ -593,13 +677,16 @@ jobs:
         which javac && javac -version
     - name: Build RocksDBJava Universal Binary Static Library
       run: make V=1 J=16 -j16 rocksdbjavastaticosx_ub
+    - uses: "./.github/actions/teardown-ccache"
+      if: always()
     - uses: "./.github/actions/post-steps"
   build-linux-java-pmd:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-java-pmd' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu
     container:
-      image: evolvedbinary/rocksjava:rockylinux8_x64-be
+      image: evolvedbinary/rocksjava:alpine3_x64-be
       options: --shm-size=16gb
     steps:
     - uses: actions/checkout@v4.1.0
@@ -621,12 +708,20 @@ jobs:
         name: maven-site
         path: "${{ github.workspace }}/java/target/site"
   build-linux-arm:
-    if: ${{ github.repository_owner == 'facebook' }}
+    if: needs.config.outputs.only_job == 'build-linux-arm' || (needs.config.outputs.only_job == '' && github.repository_owner == 'facebook')
+    needs: config
     runs-on:
       labels: 4-core-ubuntu-arm
     steps:
       - uses: actions/checkout@v4.1.0
       - uses: "./.github/actions/pre-steps"
-      - run: sudo apt-get update && sudo apt-get install -y build-essential
+      - run: sudo apt-get update && sudo apt-get install -y build-essential ccache
+      - uses: "./.github/actions/setup-ccache"
+        with:
+          cache-key-prefix: arm
       - run: ROCKSDBTESTS_PLATFORM_DEPENDENT=only make V=1 J=4 -j4 all_but_some_tests check_some
+      - name: Print ccache stats
+        run: ccache -s
+        if: always()
+        shell: bash
       - uses: "./.github/actions/post-steps"

.github/workflows/weekly.yml

@@ -0,0 +1,20 @@
+name: facebook/rocksdb/weekly
+on:
+  schedule:
+  - cron: 0 9 * * 0
+  workflow_dispatch:
+permissions: {}
+jobs:
+  build-linux-valgrind:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 16-core-ubuntu
+    timeout-minutes: 840
+    container:
+      image: ghcr.io/facebook/rocksdb_ubuntu:22.1
+      options: --shm-size=16gb
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - run: make V=1 -j20 valgrind_test
+    - uses: "./.github/actions/post-steps"

.gitignore

@@ -102,3 +102,11 @@ cmake-build-*
 third-party/folly/
 .cache
 *.sublime-*
+
+# Claude Code local settings
+.claude/settings.local.json
+
+tools/__pycache__/
+# Keep documentation trackable even if broader ignores match names like "*_test".
+!docs/
+!docs/**

AGENTS.md

@@ -0,0 +1,9 @@
+# Agent Instructions
+
+This repository's authoritative agent instructions live in `CLAUDE.md`.
+
+Read and follow [`CLAUDE.md`](./CLAUDE.md) in full before making changes or
+reviewing code in this checkout.
+
+If there is any ambiguity between this file and `CLAUDE.md`, `CLAUDE.md` takes
+precedence.

BUCK

@@ -1,12 +1,14 @@
 # This file @generated by:
 #$ python3 buckifier/buckify_rocksdb.py
 # --> DO NOT EDIT MANUALLY <--
-# This file is a Facebook-specific integration for buck builds, so can
-# only be validated by Facebook employees.
+# This file is a Meta-specific integration for buck builds, so can
+# only be validated by Meta employees.
 load("//rocks/buckifier:defs.bzl", "cpp_library_wrapper","rocks_cpp_library_wrapper","cpp_binary_wrapper","cpp_unittest_wrapper","fancy_bench_wrapper","add_c_test_wrapper")
 load("@fbcode_macros//build_defs:export_files.bzl", "export_file")
 
 
+oncall("rocksdb_point_of_contact")
+
 cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "cache/cache.cc",
         "cache/cache_entry_roles.cc",
@@ -30,12 +32,14 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "db/blob/blob_file_cache.cc",
         "db/blob/blob_file_garbage.cc",
         "db/blob/blob_file_meta.cc",
+        "db/blob/blob_file_partition_manager.cc",
         "db/blob/blob_file_reader.cc",
         "db/blob/blob_garbage_meter.cc",
         "db/blob/blob_log_format.cc",
         "db/blob/blob_log_sequential_reader.cc",
         "db/blob/blob_log_writer.cc",
         "db/blob/blob_source.cc",
+        "db/blob/blob_write_batch_transformer.cc",
         "db/blob/prefetch_buffer_collection.cc",
         "db/builder.cc",
         "db/c.cc",
@@ -88,6 +92,7 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "db/memtable_list.cc",
         "db/merge_helper.cc",
         "db/merge_operator.cc",
+        "db/multi_scan.cc",
         "db/output_validator.cc",
         "db/periodic_task_scheduler.cc",
         "db/range_del_aggregator.cc",
@@ -103,8 +108,10 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "db/version_edit.cc",
         "db/version_edit_handler.cc",
         "db/version_set.cc",
+        "db/version_util.cc",
         "db/wal_edit.cc",
         "db/wal_manager.cc",
+        "db/wide/read_path_blob_resolver.cc",
         "db/wide/wide_column_serialization.cc",
         "db/wide/wide_columns.cc",
         "db/wide/wide_columns_helper.cc",
@@ -113,6 +120,7 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "db/write_controller.cc",
         "db/write_stall_stats.cc",
         "db/write_thread.cc",
+        "db_stress_tool/db_stress_compression_manager.cc",
         "env/composite_env.cc",
         "env/env.cc",
         "env/env_chroot.cc",
@@ -203,6 +211,7 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "table/block_based/hash_index_reader.cc",
         "table/block_based/index_builder.cc",
         "table/block_based/index_reader_common.cc",
+        "table/block_based/multi_scan_index_iterator.cc",
         "table/block_based/parsed_full_filter_block.cc",
         "table/block_based/partitioned_filter_block.cc",
         "table/block_based/partitioned_index_iterator.cc",
@@ -249,6 +258,7 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "trace_replay/trace_record_result.cc",
         "trace_replay/trace_replay.cc",
         "util/async_file_reader.cc",
+        "util/auto_tune_compressor.cc",
         "util/build_version.cc",
         "util/cleanable.cc",
         "util/coding.cc",
@@ -263,10 +273,12 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "util/dynamic_bloom.cc",
         "util/file_checksum_helper.cc",
         "util/hash.cc",
+        "util/io_dispatcher_imp.cc",
         "util/murmurhash.cc",
         "util/random.cc",
         "util/rate_limiter.cc",
         "util/ribbon_config.cc",
+        "util/simple_mixed_compressor.cc",
         "util/slice.cc",
         "util/status.cc",
         "util/stderr_logger.cc",
@@ -322,6 +334,7 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "utilities/secondary_index/simple_secondary_index.cc",
         "utilities/simulator_cache/cache_simulator.cc",
         "utilities/simulator_cache/sim_cache.cc",
+        "utilities/sorted_run_builder/sorted_run_builder.cc",
         "utilities/table_properties_collectors/compact_for_tiering_collector.cc",
         "utilities/table_properties_collectors/compact_on_deletion_collector.cc",
         "utilities/trace/file_trace_reader_writer.cc",
@@ -355,6 +368,9 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "utilities/transactions/write_prepared_txn_db.cc",
         "utilities/transactions/write_unprepared_txn.cc",
         "utilities/transactions/write_unprepared_txn_db.cc",
+        "utilities/trie_index/bitvector.cc",
+        "utilities/trie_index/louds_trie.cc",
+        "utilities/trie_index/trie_index_factory.cc",
         "utilities/ttl/db_ttl_impl.cc",
         "utilities/types_util.cc",
         "utilities/wal_filter.cc",
@@ -362,10 +378,10 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
         "utilities/write_batch_with_index/write_batch_with_index_internal.cc",
     ], deps=[
         "//folly/container:f14_hash",
-        "//folly/experimental/coro:blocking_wait",
-        "//folly/experimental/coro:collect",
-        "//folly/experimental/coro:coroutine",
-        "//folly/experimental/coro:task",
+        "//folly/coro:blocking_wait",
+        "//folly/coro:collect",
+        "//folly/coro:coroutine",
+        "//folly/coro:task",
         "//folly/synchronization:distributed_mutex",
     ], headers=glob(["**/*.h"]), link_whole=False, extra_test_libs=False)
 
@@ -415,16 +431,19 @@ cpp_library_wrapper(name="rocksdb_tools_lib", srcs=[
 
 cpp_library_wrapper(name="rocksdb_cache_bench_tools_lib", srcs=["cache/cache_bench_tool.cc"], deps=[":rocksdb_lib"], headers=[], link_whole=False, extra_test_libs=False)
 
+cpp_library_wrapper(name="rocksdb_point_lock_bench_tools_lib", srcs=["utilities/transactions/lock/point/point_lock_bench_tool.cc"], deps=[":rocksdb_lib"], headers=[], link_whole=False, extra_test_libs=False)
+
 rocks_cpp_library_wrapper(name="rocksdb_stress_lib", srcs=[
         "db_stress_tool/batched_ops_stress.cc",
         "db_stress_tool/cf_consistency_stress.cc",
         "db_stress_tool/db_stress_common.cc",
+        "db_stress_tool/db_stress_compaction_service.cc",
+        "db_stress_tool/db_stress_compression_manager.cc",
         "db_stress_tool/db_stress_driver.cc",
         "db_stress_tool/db_stress_filters.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_stat.cc",
         "db_stress_tool/db_stress_test_base.cc",
         "db_stress_tool/db_stress_tool.cc",
         "db_stress_tool/db_stress_wide_merge_operator.cc",
@@ -446,6 +465,8 @@ cpp_binary_wrapper(name="db_bench", srcs=["tools/db_bench.cc"], deps=[":rocksdb_
 
 cpp_binary_wrapper(name="cache_bench", srcs=["cache/cache_bench.cc"], deps=[":rocksdb_cache_bench_tools_lib"], extra_preprocessor_flags=[], extra_bench_libs=False)
 
+cpp_binary_wrapper(name="point_lock_bench", srcs=["utilities/transactions/lock/point/point_lock_bench.cc"], deps=[":rocksdb_point_lock_bench_tools_lib"], extra_preprocessor_flags=[], extra_bench_libs=False)
+
 cpp_binary_wrapper(name="ribbon_bench", srcs=["microbench/ribbon_bench.cc"], deps=[], extra_preprocessor_flags=[], extra_bench_libs=True)
 
 cpp_binary_wrapper(name="db_basic_bench", srcs=["microbench/db_basic_bench.cc"], deps=[], extra_preprocessor_flags=[], extra_bench_libs=True)
@@ -4709,6 +4730,12 @@ cpp_unittest_wrapper(name="compressed_secondary_cache_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="compression_test",
+            srcs=["util/compression_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="configurable_test",
             srcs=["options/configurable_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -4781,6 +4808,12 @@ cpp_unittest_wrapper(name="db_blob_corruption_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="db_blob_direct_write_test",
+            srcs=["db/blob/db_blob_direct_write_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="db_blob_index_test",
             srcs=["db/blob/db_blob_index_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -4805,6 +4838,12 @@ cpp_unittest_wrapper(name="db_clip_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="db_compaction_abort_test",
+            srcs=["db/db_compaction_abort_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="db_compaction_filter_test",
             srcs=["db/db_compaction_filter_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -4829,6 +4868,12 @@ cpp_unittest_wrapper(name="db_encryption_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="db_etc3_test",
+            srcs=["db/db_etc3_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="db_flush_test",
             srcs=["db/db_flush_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -4907,6 +4952,12 @@ cpp_unittest_wrapper(name="db_merge_operator_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="db_open_with_config_test",
+            srcs=["db/db_open_with_config_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="db_options_test",
             srcs=["db/db_options_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -4997,6 +5048,12 @@ cpp_unittest_wrapper(name="db_wide_basic_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="db_wide_blob_direct_write_test",
+            srcs=["db/wide/db_wide_blob_direct_write_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="db_with_timestamp_basic_test",
             srcs=["db/db_with_timestamp_basic_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -5107,6 +5164,12 @@ cpp_unittest_wrapper(name="faiss_ivf_index_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="fault_injection_fs_test",
+            srcs=["utilities/fault_injection_fs_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="fault_injection_test",
             srcs=["db/fault_injection_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -5185,6 +5248,18 @@ cpp_unittest_wrapper(name="inlineskiplist_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="interval_test",
+            srcs=["util/interval_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
+cpp_unittest_wrapper(name="io_dispatcher_test",
+            srcs=["util/io_dispatcher_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="io_posix_test",
             srcs=["env/io_posix_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -5365,6 +5440,12 @@ cpp_unittest_wrapper(name="plain_table_db_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="point_lock_manager_stress_test",
+            srcs=["utilities/transactions/lock/point/point_lock_manager_stress_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="point_lock_manager_test",
             srcs=["utilities/transactions/lock/point/point_lock_manager_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -5473,6 +5554,12 @@ cpp_unittest_wrapper(name="slice_transform_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="sorted_run_builder_test",
+            srcs=["utilities/sorted_run_builder/sorted_run_builder_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="sst_dump_test",
             srcs=["tools/sst_dump_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -5575,6 +5662,18 @@ cpp_unittest_wrapper(name="transaction_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="trie_index_db_test",
+            srcs=["utilities/trie_index/trie_index_db_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
+cpp_unittest_wrapper(name="trie_index_test",
+            srcs=["utilities/trie_index/trie_index_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="ttl_test",
             srcs=["utilities/ttl/ttl_test.cc"],
             deps=[":rocksdb_test_lib"],
@@ -5677,6 +5776,12 @@ cpp_unittest_wrapper(name="write_controller_test",
             extra_compiler_flags=[])
 
 
+cpp_unittest_wrapper(name="write_prepared_transaction_seqno_test",
+            srcs=["utilities/transactions/write_prepared_transaction_seqno_test.cc"],
+            deps=[":rocksdb_test_lib"],
+            extra_compiler_flags=[])
+
+
 cpp_unittest_wrapper(name="write_prepared_transaction_test",
             srcs=["utilities/transactions/write_prepared_transaction_test.cc"],
             deps=[":rocksdb_test_lib"],

CLAUDE.md

@@ -0,0 +1,331 @@
+# RocksDB Code Generation and Review Guidance
+
+This document provides guidance for generating and reviewing code in the RocksDB project, derived from analysis of code review feedback across hundreds of complex merged Pull Requests. Use this as a reference when writing code with AI assistants or conducting code reviews.
+
+---
+
+## General Best Practices
+
+### Code Quality and Maintainability
+
+**Clarity and Readability:** Write clear, self-documenting code. Use meaningful variable names, add comments for complex logic, and structure code to minimize cognitive load. Avoid clever tricks that sacrifice readability for marginal performance gains unless absolutely necessary.
+
+**Consistent Style:** Follow existing code style conventions. RocksDB uses `.clang-format` for formatting, specific naming conventions, and structural patterns. Deviations from these patterns are frequently flagged in reviews.
+
+**Error Handling:** Ensure robust error handling throughout the codebase. Use RocksDB's `Status` type consistently, propagate errors appropriately, and avoid silently ignoring failures. Reviewers pay close attention to edge cases and failure modes.
+
+### Testing Philosophy
+
+**Comprehensive Coverage:** Every change should include appropriate test coverage. This includes unit tests for isolated functionality, integration tests for component interactions, and stress tests for concurrency and performance validation. Reviewers will ask for additional tests if coverage is insufficient.
+
+**Edge Cases and Failure Modes:** Tests should explicitly cover edge cases, boundary conditions, and potential failure scenarios. This is especially important for changes affecting core database operations, compaction, or recovery logic.
+
+**Platform-Specific Testing:** RocksDB supports multiple platforms (Linux, Windows, macOS) and compilers (GCC, Clang, MSVC). Changes should be tested across relevant platforms, particularly when touching platform-specific code or using compiler-specific features.
+
+### Performance Considerations
+
+**⚠️ PERFORMANCE IS CRITICAL:** RocksDB is a high-performance storage engine where every CPU cycle and memory access matters. When writing code, always evaluate from a performance perspective. This is not optional—performance-aware coding is a fundamental requirement for all contributions.
+
+**Benchmarking and Profiling:** Performance claims should be backed by empirical evidence. Use RocksDB's benchmarking tools (e.g., `db_bench`) to validate improvements. Reviewers will request benchmark results for changes that could impact performance.
+
+**Memory Allocation:** Minimize dynamic memory allocations, especially in hot paths. Prefer stack allocation over heap allocation. Reuse buffers when possible. Consider using arena allocators or memory pools for frequent small allocations. Every `new`, `malloc`, or container resize has a cost.
+
+**Memory Copy:** Avoid unnecessary memory copies. Use move semantics, `std::string_view`, `Slice`, and pass-by-reference where appropriate. Be aware of implicit copies in STL containers and function returns. Prefer in-place operations over copy-and-modify patterns.
+
+**CPU Cache Efficiency:** Design data structures and access patterns to be cache-friendly. Keep frequently accessed data together (data locality). Prefer sequential memory access over random access. Be mindful of cache line sizes (typically 64 bytes) and avoid false sharing in concurrent code. Consider struct packing and field ordering to improve cache utilization.
+
+**Loop Optimization:** Look for opportunities to collapse nested loops, reduce loop overhead, and minimize branch mispredictions. Hoist invariant computations out of loops. Consider loop unrolling for tight inner loops. Batch operations when possible to amortize per-operation overhead.
+
+**SIMD and Vectorization:** Leverage SIMD instructions (SSE, AVX) for data-parallel operations when appropriate. Structure data to enable auto-vectorization by the compiler. Consider explicit SIMD intrinsics for critical hot paths like checksum computation, encoding/decoding, and bulk data processing.
+
+**Branch Prediction:** Minimize unpredictable branches in hot paths. Use `LIKELY`/`UNLIKELY` macros to hint branch prediction. Consider branchless alternatives for simple conditionals. Order switch cases and if-else chains by frequency.
+
+**Memory and Resource Management:** Be mindful of memory allocations, especially in hot paths. Use RAII patterns, smart pointers, and RocksDB's memory management utilities appropriately.
+
+**Hot Path Analysis:** When deciding how aggressively to optimize code, consider whether it's on a hot path:
+- **Hot path** (executed thousands+ times, e.g., data access, iteration, compaction loops): Performance is paramount. Apply all optimization techniques—loop collapsing, SIMD, cache optimization, pre-allocation, etc. The cost of each operation is multiplied by execution frequency.
+- **Cold path** (executed rarely, e.g., DB open, configuration parsing, error handling): Maintainability and clarity are more important. Prefer readable code over micro-optimizations. Complex optimizations here add maintenance burden with negligible performance benefit.
+- **Warm path** (moderate frequency): Balance both concerns. Use profiling data to guide optimization decisions.
+
+**Avoid Premature Optimization:** While performance is critical, focus on correctness first, then optimize based on profiling data. However, be performance-aware from the start—choosing the right algorithm and data structure upfront is not premature optimization. Use the hot path analysis above to decide how much optimization effort is warranted.
+
+### API Design and Compatibility
+
+**Backwards Compatibility:** RocksDB maintains strong backwards compatibility guarantees. Breaking changes are rare and require extensive justification. When deprecating features, follow the project's deprecation policy (typically spanning multiple releases).
+
+**API Consistency:** New APIs should be consistent with existing patterns. Use similar naming conventions, parameter ordering, and return types. Reviewers will suggest changes to improve consistency with the broader codebase.
+
+**Documentation:** Public APIs must be thoroughly documented. Include usage examples, parameter descriptions, and notes on thread safety, performance characteristics, and compatibility considerations.
+
+---
+
+## Component-Specific Guidance
+
+### Database Core (`db`)
+
+The database core handles write-ahead logging (WAL), memtables, compaction, and recovery. This component receives the most scrutiny in code reviews.
+
+**Concurrency and Thread Safety:** Database operations are highly concurrent. Reviewers carefully examine locking strategies, atomic operations, and memory ordering. Document synchronization assumptions clearly. Use appropriate memory ordering semantics (`acquire`/`release` vs. `seq_cst`).
+
+**Compaction Logic:** Changes to compaction are complex and high-risk. Ensure that compaction logic respects configured parameters, handles edge cases (empty databases, single-file compactions), and maintains correctness under concurrent operations.
+
+**Error Propagation:** Database operations can fail in many ways (I/O errors, corruption, resource exhaustion). Ensure that errors are properly propagated, logged, and handled. Avoid assertions in production code paths.
+
+**Testing:** Database core changes require extensive testing, including unit tests, integration tests, and stress tests. Test with various configurations, compaction styles, and concurrent workloads.
+
+### Public Headers (`include`)
+
+Public headers define RocksDB's API surface. Changes here have the highest compatibility impact.
+
+**API Design:** New APIs should be intuitive, consistent with existing patterns, and well-documented. Consider how the API will be used in practice and avoid adding unnecessary complexity.
+
+**Backwards Compatibility:** Breaking changes to public APIs require extensive justification and a deprecation plan. Maintain ABI compatibility for bug fixes and patch releases.
+
+**Documentation:** Every public API must be thoroughly documented with usage examples, parameter descriptions, and notes on thread safety and performance characteristics.
+
+**Deprecation:** When deprecating APIs, follow the project's policy. Mark deprecated APIs clearly, provide migration guidance, and maintain support for at least one major release.
+
+### Internal Utilities (`util`)
+
+Internal utilities provide common functionality used throughout the codebase.
+
+**Code Reuse:** Utilities should be general-purpose and reusable. Avoid duplicating functionality that already exists elsewhere in the codebase.
+
+**Error Handling:** Utility functions should handle errors robustly and propagate them appropriately. Consider edge cases like overflow, underflow, and invalid inputs.
+
+**Testing:** Utility functions should have comprehensive test coverage, including edge cases and failure modes. Consider adding death tests for assertions.
+
+**Performance:** Utilities are often used in hot paths. Ensure that implementations are efficient and avoid unnecessary allocations or copies.
+
+### Table Management (`table`)
+
+Table management handles SST file format, block-based tables, and table readers/writers.
+
+**Block Format and Checksums:** Changes to block format require extreme care. Ensure that checksums are computed and verified correctly. Test with various compression algorithms and block sizes.
+
+**Iterator Correctness:** Table iterators are used throughout the codebase. Ensure that iterator semantics (Seek, Next, Prev) are correct, especially at boundaries and with deletions.
+
+**Caching and Prefetching:** Table readers interact with the block cache and prefetching logic. Ensure that cache keys are unique and that prefetching respects configured limits.
+
+**Performance:** Table operations are performance-critical. Benchmark changes that could impact read or write performance.
+
+### Utilities (`utilities`)
+
+Utilities include optional features like transactions, backup engine, and checkpoint.
+
+**Feature Isolation:** Utilities should be self-contained and not introduce unnecessary dependencies on core database internals.
+
+**Deprecation and Cleanup:** Legacy features are being phased out. When removing deprecated code, ensure that migration paths are documented and that users have sufficient warning.
+
+**Cross-Platform Compatibility:** Utilities often interact with OS-specific APIs. Ensure that code works on all supported platforms.
+
+### Options and Configuration (`options`)
+
+Options define RocksDB's configuration system.
+
+**Type Safety:** Use appropriate types for options (e.g., `uint32_t` for flags, scoped enums for enumerated values).
+
+**Deprecation Policy:** When deprecating options, follow the project's policy. Document the deprecation, provide migration guidance, and maintain support for at least one major release.
+
+**Dynamic Configuration:** Some options can be changed dynamically. Ensure that dynamic changes are thread-safe and take effect correctly.
+
+**Validation:** Validate option values and provide clear error messages for invalid configurations.
+
+### Cache (`cache`)
+
+Cache management is critical for RocksDB's performance.
+
+**Concurrency:** Cache operations are highly concurrent. Ensure that implementations are thread-safe and use appropriate synchronization primitives.
+
+**Performance:** Cache operations are in the hot path. Optimize for low latency and high throughput. Benchmark changes carefully.
+
+**Memory Management:** Cache implementations must manage memory carefully to avoid leaks and excessive allocations.
+
+**Eviction Policies:** Changes to eviction policies should be well-tested and benchmarked to ensure they improve overall performance.
+
+---
+
+## Code Review Checklist
+
+When reviewing RocksDB code (or preparing code for review), use this checklist:
+
+### Correctness
+- [ ] Does the change preserve database semantics (e.g., snapshot isolation, key ordering)?
+- [ ] Are all error cases handled appropriately?
+- [ ] Is the change thread-safe? Are synchronization primitives used correctly?
+- [ ] Are there any potential data races or deadlocks?
+
+### Testing
+- [ ] Does the change include appropriate test coverage?
+- [ ] Are edge cases and failure modes tested?
+- [ ] Have the tests been run on all supported platforms?
+- [ ] Are stress tests passing?
+
+### Performance
+- [ ] Are there benchmark results for performance-sensitive changes?
+- [ ] Does the change avoid unnecessary allocations or copies?
+- [ ] Are hot paths optimized appropriately?
+
+### API and Compatibility
+- [ ] Is the change backwards compatible?
+- [ ] Are new APIs consistent with existing patterns?
+- [ ] Is the public API documented?
+- [ ] Are deprecated features handled according to policy?
+
+### Code Quality
+- [ ] Does the code follow RocksDB's style conventions?
+- [ ] Is the code clear and maintainable?
+- [ ] Are comments and documentation sufficient?
+- [ ] Are there any code smells or anti-patterns?
+
+---
+
+## Common Review Feedback Patterns
+
+The following patterns emerged as frequent sources of review feedback:
+
+1. **Test Coverage:** Reviewers frequently request additional tests for edge cases, platform-specific behavior, and failure modes. Complex changes require comprehensive test coverage including unit tests, integration tests, and stress tests.
+
+2. **Error Handling:** Ensure proper error propagation using RocksDB's `Status` type. Avoid silent failures and provide clear error messages that include context about what failed and why.
+
+3. **API Design:** New APIs should be consistent with existing patterns. Use descriptive names that follow established conventions. Avoid breaking changes without strong justification and a clear deprecation plan.
+
+4. **Documentation:** Public APIs must be documented with usage examples and notes on thread safety, performance characteristics, and compatibility considerations. Complex internal logic should also be well-commented.
+
+5. **Performance:** Performance-sensitive changes require benchmark results to validate improvements. Use `db_bench` and other profiling tools to measure impact. Avoid premature optimization that adds complexity without measurable benefit.
+
+6. **Concurrency:** Thread safety is critical in RocksDB. Document synchronization assumptions clearly. Use appropriate memory ordering semantics. Consider potential race conditions and deadlocks.
+
+7. **Code Style:** Follow existing conventions for naming, formatting, and structure. Use `.clang-format` for consistent formatting. Prefer scoped enums (`enum class`) over unscoped enums.
+
+8. **Backwards Compatibility:** RocksDB maintains strong compatibility guarantees. Breaking changes require extensive justification. When deprecating features, provide migration guidance and maintain support across multiple releases.
+
+9. **Refactoring:** Reviewers appreciate refactoring that improves code readability and maintainability. Look for opportunities to deduplicate code and simplify complex logic.
+
+10. **Platform Compatibility:** Ensure changes work correctly on all supported platforms (Linux, Windows, macOS) and with all supported compilers (GCC, Clang, MSVC).
+
+---
+
+## Important tips
+
+### Build system
+* There are 3 build system. Make, CMake, BUCK(meta internal).
+* When a new .cc file is added, update Makefile, CMakeLists.txt, src.mk, BUCK.
+* Don't manually edit BUCK file, after updating src.mk, run
+    /usr/local/bin/python3 buckifier/buckify_rocksdb.py to update it
+* Use make to build and run the test. CMake and BUCK are not used locally.
+* Use `make dbg` command to build all of the unit test in debug mode.
+* For -j in make command, use the number of CPU cores to decide it.
+
+### Unit Test
+* After all of the unit tests are added, review them and try to extract common
+    reusable utility functions to reduce code duplication due to copy past between
+    unit tests. This should be done every time unit test is updated.
+* Don't use sleep to wait for certain events to happen. This will cause test to
+    be flaky. Instead, use sync point to synchronize thread progress.
+* Cap unit test execution with 60 seconds timeout.
+* When there are multiple unit tests need to be executed, try to use
+    gtest_parallel.py if available. E.g.
+    python3 ${GTEST_PARALLEL}/gtest_parallel.py ./table_test
+* After writing a test, stress-test for flakiness:
+    ```bash
+    COERCE_CONTEXT_SWITCH=1 make {test_binary}
+    ./{test_binary} --gtest_filter="*YourTestName*" --gtest_repeat=5
+    ```
+
+### Unit test dedup guidelines
+* Extract helper functions for repeated patterns such as object
+    construction, round-trip (encode → decode → verify), and common
+    assertion sequences.
+* Use table-driven tests (struct array + loop) when multiple test cases
+    share the same logic but differ only in input/expected data.
+* Prefer randomized tests over exhaustive parameter permutations. Use
+    `Random` from `util/random.h` (not `std::mt19937`). Use a time-based
+    seed with `SCOPED_TRACE("seed=" + std::to_string(seed))` so failures
+    are reproducible.
+* Keep deterministic edge-case tests separate from randomized tests
+    (error paths, boundary conditions, format verification).
+* Methods only used in tests should be private with `friend class` +
+    `TEST_F` fixture wrappers. In wrappers, always fully qualify the
+    target method to avoid infinite recursion.
+
+### Adding new public API
+    Refer to claude_md/add_public_api.md
+
+### Adding new option
+    Refer to claude_md/add_option.md
+
+### Removing deprecated option
+    Refer to claude_md/remove_option.md
+
+### Metrics
+* When adding a new feature, evaluate whether there is opportunity to add
+    metrics. Try to avoid causing performance regression on hot path when adding
+    metrics.
+
+### Stress test
+* When adding a new feature, make sure stress test covers the new option.
+
+### Component docs
+* For component-level design notes and implementation walkthroughs, start with
+    `docs/components/index.md`.
+* Documentation under `docs/components/` is organized by subsystem in
+    `docs/components/<area>/`.
+* Each subsystem directory should have an `index.md` entry point plus focused
+    chapter files for deeper topics.
+
+### DB bench update
+* When adding a performance related feature, support it in db_bench
+
+### Adding release note
+* Release note should be kept short at high level for external user consumption.
+
+### Blog posts (docs/_posts)
+* Blog post authors must be defined in `docs/_data/authors.yml` to be displayed
+
+### Final verification of the change
+* Execute make clean to clean all of the changes.
+* Execute make check to build all of the changes and execute all of the tests.
+    Note that executing all of the tests could take multiple minutes.
+* Run `ASSERT_STATUS_CHECKED=1 make check` to verify all Status objects are
+    properly checked. This catches missing error handling that can lead to
+    silent data corruption.
+
+### Monitoring make check progress
+* Use `make check-progress` to get machine-parseable JSON progress while
+    `make check` is running. This is useful for Claude Code to monitor long
+    builds without timeout issues.
+* Run `make check` in background, then poll progress:
+    ```bash
+    make check &
+    # Poll periodically:
+    make check-progress
+    ```
+* The output shows current phase and progress:
+    ```json
+    {"status":"running","phase":"compiling","completed":300,"total":919,...}
+    {"status":"running","phase":"testing","completed":1500,"total":29962,"failed":0,"percent":5,...}
+    {"status":"completed","phase":"testing","completed":29962,"total":29962,"failed":0,"percent":100,...}
+    ```
+* Phases: `compiling` -> `linking` -> `generating` -> `testing` -> `completed`
+* Key fields: `status`, `phase`, `completed`, `total`, `failed`, `percent`
+* When tests fail, `failed_tests` array shows details (up to 10 failures):
+    ```json
+    {"status":"running",...,"failed":3,"failed_tests":[
+      {"test":"cache_test-CacheTest.Usage","exit_code":1,"signal":0,"output":"...test log..."},
+      {"test":"env_test-EnvTest.Open","exit_code":0,"signal":11,"output":"...Segmentation fault..."}
+    ]}
+    ```
+* `exit_code`: non-zero means test assertion failed
+* `signal`: non-zero means test was killed (e.g., 9=SIGKILL, 6=SIGABRT, 11=SIGSEGV)
+* `output`: last 50 lines of test log including error messages and stack traces
+
+### Executing benchmark using db_bench
+* Since the goal is to measure performance, we need to build a release binary
+    using `make clean && DEBUG_LEVEL=0 make db_bench`. If there is an engine
+    crash due to bug, we need to switch back to debug build. Make sure to run
+    `make clean` before running `make dbg`.
+
+### Formatting code
+* After making change, use `make format-auto` to auto-apply formatting without
+    interactive prompts (Claude Code friendly).

CMakeLists.txt

@@ -27,7 +27,7 @@
 #
 # Linux:
 #
-# 1. Install a recent toolchain if you're on a older distro. C++17 required (GCC >= 7, Clang >= 5)
+# 1. Install a recent toolchain if you're on a older distro. C++20 required (GCC >= 11, Clang >= 10)
 # 2. mkdir build; cd build
 # 3. cmake ..
 # 4. make -j
@@ -80,11 +80,17 @@ if(NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE "${default_build_type}" CACHE STRING
     "Default BUILD_TYPE is ${default_build_type}" FORCE)
 endif()
+message(STATUS "CMAKE_BUILD_TYPE is set to ${CMAKE_BUILD_TYPE}")
 
+# Use ccache for compilation if available. Use CMAKE_C/CXX_COMPILER_LAUNCHER
+# instead of RULE_LAUNCH_COMPILE to avoid double-wrapping when ccache is also
+# injected via PATH (e.g., /usr/lib/ccache or brew --prefix ccache/libexec).
+# Note: we intentionally do NOT set RULE_LAUNCH_LINK because ccache cannot
+# cache link operations -- it only adds overhead.
 find_program(CCACHE_FOUND ccache)
 if(CCACHE_FOUND)
-  set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ccache)
-  set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK ccache)
+  set(CMAKE_C_COMPILER_LAUNCHER ccache)
+  set(CMAKE_CXX_COMPILER_LAUNCHER ccache)
 endif(CCACHE_FOUND)
 
 option(WITH_JEMALLOC "build with JeMalloc" OFF)
@@ -100,7 +106,7 @@ endif()
 option(ROCKSDB_BUILD_SHARED "Build shared versions of the RocksDB libraries" ON)
 
 if( NOT DEFINED CMAKE_CXX_STANDARD )
-  set(CMAKE_CXX_STANDARD 17)
+  set(CMAKE_CXX_STANDARD 20)
 endif()
 
 include(CMakeDependentOption)
@@ -132,7 +138,9 @@ else()
     option(WITH_GFLAGS "build with GFlags" ON)
   endif()
   set(GFLAGS_LIB)
-  if(WITH_GFLAGS)
+  # Skip all gflags detection and setup when USE_FOLLY or USE_COROUTINES is enabled
+  # since Folly provides its own gflags (USE_COROUTINES automatically sets USE_FOLLY)
+  if(WITH_GFLAGS AND NOT USE_FOLLY AND NOT USE_COROUTINES)
     # Config with namespace available since gflags 2.2.2
     option(GFLAGS_USE_TARGET_NAMESPACE "Use gflags import target with namespace." ON)
     find_package(gflags CONFIG)
@@ -151,6 +159,9 @@ else()
     include_directories(${GFLAGS_INCLUDE_DIR})
     list(APPEND THIRDPARTY_LIBS ${GFLAGS_LIB})
     add_definitions(-DGFLAGS=1)
+  elseif(WITH_GFLAGS AND (USE_FOLLY OR USE_COROUTINES))
+    # Still set the DGFLAGS=1 define when using Folly since Folly provides gflags
+    add_definitions(-DGFLAGS=1)
   endif()
 
   if(WITH_SNAPPY)
@@ -203,9 +214,20 @@ if(WIN32 AND MSVC)
   endif()
 endif()
 
+option(WIN_CI "Accelerate build speed and reduce build artifect size for github CI with MSVC" OFF)
+
 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 /wd4996 /wd4100 /wd4324")
+  if(WIN_CI)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP /nologo /EHsc /Gd /GR /GF /fp:precise /Zc:wchar_t /Zc:forScope /errorReport:queue")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /FC /W4 /wd4127 /wd4996 /wd4100 /wd4324 /wd4702")
+  else()
+    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 /wd4996 /wd4100 /wd4324")
+  endif()
+  if(CMAKE_BUILD_TYPE STREQUAL "Release")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /DNDEBUG")
+    message(STATUS "Setting /DNDEBUG as CMAKE_BUILD_TYPE is set to ${CMAKE_BUILD_TYPE}")
+  endif()
 else()
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -W -Wextra -Wall -pthread")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers -Wno-strict-aliasing -Wno-invalid-offsetof")
@@ -313,8 +335,7 @@ if(NOT MSVC)
 endif()
 
 # Check if -latomic is required or not
-if (NOT MSVC)
-  set(CMAKE_REQUIRED_FLAGS "--std=c++17")
+if (NOT MSVC AND NOT APPLE)
   CHECK_CXX_SOURCE_COMPILES("
 #include <atomic>
 std::atomic<uint64_t> x(0);
@@ -451,24 +472,33 @@ else()
   endif()
 endif()
 
-# Used to run CI build and tests so we can run faster
+# Used to run optimized debug build and tests so we can run faster
 option(OPTDBG "Build optimized debug build with MSVC" OFF)
 option(WITH_RUNTIME_DEBUG "build with debug version of runtime library" ON)
 if(MSVC)
-  if(OPTDBG)
+  if (WIN_CI)
     message(STATUS "Debug optimization is enabled")
     set(CMAKE_CXX_FLAGS_DEBUG "/Oxt")
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} /DEBUG:FASTLINK")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /DEBUG:FASTLINK")
   else()
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /RTC1")
-
-    # Minimal Build is deprecated after MSVC 2015
-    if( MSVC_VERSION GREATER 1900 )
-      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm-")
+    if(OPTDBG)
+      message(STATUS "Debug optimization is enabled")
+      set(CMAKE_CXX_FLAGS_DEBUG "/Oxt")
     else()
-      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm")
-    endif()
+      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /RTC1")
 
+      # Minimal Build is deprecated after MSVC 2015
+      if( MSVC_VERSION GREATER 1900 )
+        set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm-")
+      else()
+        set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm")
+      endif()
+    endif()
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} /DEBUG")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /DEBUG")
   endif()
+
   if(WITH_RUNTIME_DEBUG)
     set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /${RUNTIME_LIBRARY}d")
   else()
@@ -476,8 +506,6 @@ if(MSVC)
   endif()
   set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /Oxt /Zp8 /Gm- /Gy /${RUNTIME_LIBRARY}")
 
-  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} /DEBUG")
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /DEBUG")
 endif()
 
 if(CMAKE_COMPILER_IS_GNUCXX)
@@ -492,6 +520,15 @@ elseif(CMAKE_SYSTEM_NAME MATCHES "iOS")
   add_definitions(-DOS_MACOSX -DIOS_CROSS_COMPILE)
 elseif(CMAKE_SYSTEM_NAME MATCHES "Linux")
   add_definitions(-DOS_LINUX)
+  # Use lld linker if available for faster linking (12x faster than ld.bfd)
+  if(NOT ROCKSDB_NO_FAST_LINKER)
+    execute_process(COMMAND ${CMAKE_CXX_COMPILER} -fuse-ld=lld -Wl,--version
+      OUTPUT_VARIABLE LLD_VERSION_OUTPUT ERROR_QUIET RESULT_VARIABLE LLD_RESULT)
+    if(LLD_RESULT EQUAL 0 AND LLD_VERSION_OUTPUT MATCHES "LLD")
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=lld")
+      set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -fuse-ld=lld")
+    endif()
+  endif()
 elseif(CMAKE_SYSTEM_NAME MATCHES "SunOS")
   add_definitions(-DOS_SOLARIS)
 elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD")
@@ -629,12 +666,46 @@ if(USE_FOLLY)
     ${FOLLY_INST_PATH}/lib/cmake/folly/folly-targets.cmake)
 
     include(${FOLLY_INST_PATH}/lib/cmake/folly/folly-config.cmake)
+
+    # Fix gflags library name for debug builds
+    if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,-rpath=${GFLAGS_INST_PATH}/lib")
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${GFLAGS_INST_PATH}/lib/libgflags_debug.so.2.2")
+    endif()
+  endif()
+
+  # Folly itself uses gflags transitively, but RocksDB tools and benchmarks
+  # also call gflags APIs directly, so they need an explicit link dependency.
+  if(WITH_GFLAGS)
+    if(NOT TARGET gflags::gflags AND NOT TARGET gflags_shared AND
+       NOT gflags_LIBRARIES)
+      find_package(gflags CONFIG QUIET)
+      if(NOT gflags_FOUND)
+        find_package(gflags REQUIRED)
+      endif()
+    endif()
+    if(TARGET gflags::gflags)
+      set(GFLAGS_LIB gflags::gflags)
+    elseif(TARGET gflags_shared)
+      set(GFLAGS_LIB gflags_shared)
+    elseif(DEFINED GFLAGS_TARGET AND TARGET ${GFLAGS_TARGET})
+      set(GFLAGS_LIB ${GFLAGS_TARGET})
+    elseif(gflags_LIBRARIES)
+      set(GFLAGS_LIB ${gflags_LIBRARIES})
+    else()
+      message(FATAL_ERROR
+        "WITH_GFLAGS is enabled, but no gflags library could be resolved")
+    endif()
+    list(APPEND THIRDPARTY_LIBS ${GFLAGS_LIB})
   endif()
 
   add_compile_definitions(USE_FOLLY FOLLY_NO_CONFIG HAVE_CXX11_ATOMIC)
   list(APPEND THIRDPARTY_LIBS Folly::folly)
   set(FOLLY_LIBS Folly::folly)
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--copy-dt-needed-entries")
+  # --copy-dt-needed-entries is ld.bfd-specific; lld handles DT_NEEDED transitively
+  if(NOT CMAKE_EXE_LINKER_FLAGS MATCHES "fuse-ld=lld")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--copy-dt-needed-entries")
+  endif()
 endif()
 find_package(Threads REQUIRED)
 
@@ -661,6 +732,7 @@ set(SOURCES
         db/blob/blob_file_addition.cc
         db/blob/blob_file_builder.cc
         db/blob/blob_file_cache.cc
+        db/blob/blob_file_partition_manager.cc
         db/blob/blob_file_garbage.cc
         db/blob/blob_file_meta.cc
         db/blob/blob_file_reader.cc
@@ -669,6 +741,7 @@ set(SOURCES
         db/blob/blob_log_sequential_reader.cc
         db/blob/blob_log_writer.cc
         db/blob/blob_source.cc
+        db/blob/blob_write_batch_transformer.cc
         db/blob/prefetch_buffer_collection.cc
         db/builder.cc
         db/c.cc
@@ -721,6 +794,7 @@ set(SOURCES
         db/memtable_list.cc
         db/merge_helper.cc
         db/merge_operator.cc
+        db/multi_scan.cc
         db/output_validator.cc
         db/periodic_task_scheduler.cc
         db/range_del_aggregator.cc
@@ -736,8 +810,10 @@ set(SOURCES
         db/version_edit.cc
         db/version_edit_handler.cc
         db/version_set.cc
+        db/version_util.cc
         db/wal_edit.cc
         db/wal_manager.cc
+        db/wide/read_path_blob_resolver.cc
         db/wide/wide_column_serialization.cc
         db/wide/wide_columns.cc
         db/wide/wide_columns_helper.cc
@@ -746,6 +822,7 @@ set(SOURCES
         db/write_controller.cc
         db/write_stall_stats.cc
         db/write_thread.cc
+        db_stress_tool/db_stress_compression_manager.cc
         env/composite_env.cc
         env/env.cc
         env/env_chroot.cc
@@ -811,6 +888,7 @@ set(SOURCES
         table/block_based/block_based_table_builder.cc
         table/block_based/block_based_table_factory.cc
         table/block_based/block_based_table_iterator.cc
+        table/block_based/multi_scan_index_iterator.cc
         table/block_based/block_based_table_reader.cc
         table/block_based/block_builder.cc
         table/block_based/block_cache.cc
@@ -874,17 +952,20 @@ set(SOURCES
         trace_replay/trace_record.cc
         trace_replay/trace_replay.cc
         util/async_file_reader.cc
+        util/auto_tune_compressor.cc
         util/cleanable.cc
         util/coding.cc
         util/compaction_job_stats_impl.cc
         util/comparator.cc
         util/compression.cc
+        util/simple_mixed_compressor.cc
         util/compression_context_cache.cc
         util/concurrent_task_limiter_impl.cc
         util/crc32c.cc
         util/data_structure.cc
         util/dynamic_bloom.cc
         util/hash.cc
+        util/io_dispatcher_imp.cc
         util/murmurhash.cc
         util/random.cc
         util/rate_limiter.cc
@@ -914,6 +995,7 @@ set(SOURCES
         utilities/cassandra/merge_operator.cc
         utilities/checkpoint/checkpoint_impl.cc
         utilities/compaction_filters.cc
+        utilities/sorted_run_builder/sorted_run_builder.cc
         utilities/compaction_filters/remove_emptyvalue_compactionfilter.cc
         utilities/counted_fs.cc
         utilities/debug.cc
@@ -965,6 +1047,9 @@ set(SOURCES
         utilities/transactions/write_prepared_txn_db.cc
         utilities/transactions/write_unprepared_txn.cc
         utilities/transactions/write_unprepared_txn_db.cc
+        utilities/trie_index/bitvector.cc
+        utilities/trie_index/louds_trie.cc
+        utilities/trie_index/trie_index_factory.cc
         utilities/types_util.cc
         utilities/ttl/db_ttl_impl.cc
         utilities/wal_filter.cc
@@ -1065,14 +1150,38 @@ if(USE_FOLLY_LITE)
     third-party/folly/folly/synchronization/DistributedMutex.cpp
     third-party/folly/folly/synchronization/ParkingLot.cpp)
   include_directories(${PROJECT_SOURCE_DIR}/third-party/folly)
+  # Add boost to the include path
   exec_program(python3 ${PROJECT_SOURCE_DIR}/third-party/folly ARGS
   build/fbcode_builder/getdeps.py show-source-dir boost OUTPUT_VARIABLE
   BOOST_SOURCE_PATH)
   exec_program(ls ARGS -d ${BOOST_SOURCE_PATH}/boost* OUTPUT_VARIABLE
   BOOST_INCLUDE_DIR)
   include_directories(${BOOST_INCLUDE_DIR})
+  # Add fmt to the include path
+  exec_program(python3 ${PROJECT_SOURCE_DIR}/third-party/folly ARGS
+  build/fbcode_builder/getdeps.py show-source-dir fmt OUTPUT_VARIABLE
+  FMT_SOURCE_PATH)
+  exec_program(ls ARGS -d ${FMT_SOURCE_PATH}/fmt*/include OUTPUT_VARIABLE
+  FMT_INCLUDE_DIR)
+  include_directories(${FMT_INCLUDE_DIR})
+
+  exec_program(python3 ${PROJECT_SOURCE_DIR}/third-party/folly ARGS
+  build/fbcode_builder/getdeps.py show-inst-dir glog OUTPUT_VARIABLE
+  GLOG_INST_PATH)
+  if(EXISTS ${GLOG_INST_PATH}/lib64)
+    set(GLOG_LIB_DIR ${GLOG_INST_PATH}/lib64)
+  else()
+    set(GLOG_LIB_DIR ${GLOG_INST_PATH}/lib)
+  endif()
+
   add_definitions(-DUSE_FOLLY -DFOLLY_NO_CONFIG)
-  list(APPEND THIRDPARTY_LIBS glog)
+  find_library(GLOG_LIBRARY NAMES glog PATHS ${GLOG_LIB_DIR} NO_DEFAULT_PATH)
+  if(NOT GLOG_LIBRARY)
+    find_library(GLOG_LIBRARY NAMES glog)
+  endif()
+  if(GLOG_LIBRARY)
+    list(APPEND THIRDPARTY_LIBS ${GLOG_LIBRARY})
+  endif()
 endif()
 
 set(ROCKSDB_STATIC_LIB rocksdb${ARTIFACT_SUFFIX})
@@ -1318,6 +1427,7 @@ if(WITH_TESTS)
         db/blob/blob_garbage_meter_test.cc
         db/blob/blob_source_test.cc
         db/blob/db_blob_basic_test.cc
+        db/blob/db_blob_direct_write_test.cc
         db/blob/db_blob_compaction_test.cc
         db/blob/db_blob_corruption_test.cc
         db/blob/db_blob_index_test.cc
@@ -1339,9 +1449,11 @@ if(WITH_TESTS)
         db/db_bloom_filter_test.cc
         db/db_compaction_filter_test.cc
         db/db_compaction_test.cc
+        db/db_compaction_abort_test.cc
         db/db_clip_test.cc
         db/db_dynamic_level_test.cc
         db/db_encryption_test.cc
+        db/db_etc3_test.cc
         db/db_flush_test.cc
         db/db_inplace_update_test.cc
         db/db_io_failure_test.cc
@@ -1353,6 +1465,7 @@ if(WITH_TESTS)
         db/db_memtable_test.cc
         db/db_merge_operator_test.cc
         db/db_merge_operand_test.cc
+        db/db_open_with_config_test.cc
         db/db_options_test.cc
         db/db_properties_test.cc
         db/db_range_del_test.cc
@@ -1405,6 +1518,7 @@ if(WITH_TESTS)
         db/wal_manager_test.cc
         db/wal_edit_test.cc
         db/wide/db_wide_basic_test.cc
+        db/wide/db_wide_blob_direct_write_test.cc
         db/wide/wide_column_serialization_test.cc
         db/wide/wide_columns_helper_test.cc
         db/write_batch_test.cc
@@ -1456,6 +1570,7 @@ if(WITH_TESTS)
         util/autovector_test.cc
         util/bloom_test.cc
         util/coding_test.cc
+        util/compression_test.cc
         util/crc32c_test.cc
         util/defer_test.cc
         util/dynamic_bloom_test.cc
@@ -1484,7 +1599,9 @@ if(WITH_TESTS)
         utilities/cassandra/cassandra_row_merge_test.cc
         utilities/cassandra/cassandra_serialize_test.cc
         utilities/checkpoint/checkpoint_test.cc
+        utilities/sorted_run_builder/sorted_run_builder_test.cc
         utilities/env_timed_test.cc
+        utilities/fault_injection_fs_test.cc
         utilities/memory/memory_test.cc
         utilities/merge_operators/string_append/stringappend_test.cc
         utilities/object_registry_test.cc
@@ -1499,11 +1616,15 @@ if(WITH_TESTS)
         utilities/transactions/optimistic_transaction_test.cc
         utilities/transactions/transaction_test.cc
         utilities/transactions/lock/point/point_lock_manager_test.cc
+        utilities/transactions/lock/point/point_lock_manager_stress_test.cc
         utilities/transactions/write_committed_transaction_ts_test.cc
         utilities/transactions/write_prepared_transaction_test.cc
+        utilities/transactions/write_prepared_transaction_seqno_test.cc
         utilities/transactions/write_unprepared_transaction_test.cc
         utilities/transactions/lock/range/range_locking_test.cc
         utilities/transactions/timestamped_snapshot_test.cc
+        utilities/trie_index/trie_index_db_test.cc
+        utilities/trie_index/trie_index_test.cc
         utilities/ttl/ttl_test.cc
         utilities/types_util_test.cc
         utilities/util_merge_operators_test.cc
@@ -1609,6 +1730,12 @@ if(WITH_BENCHMARK_TOOLS)
     utilities/persistent_cache/hash_table_bench.cc)
   target_link_libraries(hash_table_bench${ARTIFACT_SUFFIX}
     ${ROCKSDB_LIB} ${GFLAGS_LIB} ${FOLLY_LIBS})
+
+  add_executable(point_lock_bench${ARTIFACT_SUFFIX}
+    utilities/transactions/lock/point/point_lock_bench.cc
+    utilities/transactions/lock/point/point_lock_bench_tool.cc)
+  target_link_libraries(point_lock_bench${ARTIFACT_SUFFIX}
+    ${ROCKSDB_LIB} ${GFLAGS_LIB} ${FOLLY_LIBS})
 endif()
 
 option(WITH_TRACE_TOOLS "build with trace tools" ON)

Directory.Build.props

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+    <PropertyGroup>
+        <CLToolExe>ccache_msvc_compiler.bat</CLToolExe>
+        <CLToolPath>$(MSBuildThisFileDirectory)</CLToolPath>
+        <UseMultiToolTask>true</UseMultiToolTask>
+        <EnforceProcessCountAcrossBuilds>true</EnforceProcessCountAcrossBuilds>
+    </PropertyGroup>
+</Project>

HISTORY.md

@@ -1,12 +1,259 @@
 # Rocksdb Change Log
 > NOTE: Entries for next release do not go here. Follow instructions in `unreleased_history/README.txt`
 
-## 10.1.3 (04/09/2025)
-### Bug Fixes
-* Fix a bug where resurrected full_history_ts_low from a previous session that enables UDT is used by this session that disables UDT.
+## 11.2.0 (04/18/2026)
+### New Features
+* Added experimental `DBOptions::fast_sst_open` option. When enabled, RocksDB retrieves opaque file system metadata for SST files after flush, compaction, and external file ingestion, persists it in the MANIFEST, and passes it back to the file system on subsequent file opens to accelerate DB open time.
+* Added new option `min_tombstones_for_range_conversion` in `AdvancedColumnFamilyOptions`. When set to a non-zero value N, forward or reverse iteration will convert N or more contiguous point tombstones into a range tombstone in the mutable memtable. Future read operations will then be able to benefit from range tombstone optimizations. There are some limitations when it comes to table_filters, prefix_filters, and UDTs. See header comments for more details.
+* Added read-triggered compaction: a new column family option `read_triggered_compaction_threshold` (default 0, disabled) that marks SST files for compaction when their read frequency (`num_collapsible_entry_reads_sampled / file_size`) exceeds the threshold. This helps reduce read amplification for frequently-read ("hot") keys. A new DB option `max_compaction_trigger_wakeup_seconds` (default 43200s / 12 hours) controls the maximum interval for periodic compaction score re-evaluation, which is necessary for this feature to work on quiet (no-write) databases.
+
+### Public API Changes
+* Added new `WideColumnBlobResolver` interface and `CompactionFilter::FilterV4()` method, including `ResolveColumn()` / `ResolveColumns()` helpers for lazy loading blob column values in wide-column entities during compaction. This allows compaction filters to resolve blob values on-demand, avoiding unnecessary I/O for blob columns they don't need to access.
+* Changed experimental feature `ExternalTableReader::Get` and `ExternalTableReader::MultiGet` to use `PinnableSlice` instead of `std::string` for output values, enabling zero-copy pinning. This will break existing implementations.
+* Added `SstFileReader::Get` and `SstFileReader::MultiGet` overloads that accept `PinnableSlice`/`std::vector<PinnableSlice>*`, enabling zero-copy reads when the underlying `TableReader` supports pinning.
+
+### Behavior Changes
+* Prefix filter changes - when seeking to a key that is out of domain, and total_order_seek is false, total_order_seek is treated as if it were true. When prefix_same_as_start = true, now iterating past a key that is out of domain invalidates the iterator. The existing behavior does not check for InDomain in the DBIter, so Transform() can produce undefined behavior (e.g. key of size 3 on FixedPrefixTransform(4)).
+* Wide-column entities with blob-backed columns now use a new V2 on-disk encoding; older RocksDB versions that do not support wide-column blob separation will reject DBs or SSTs containing those entities.
 
-## 10.1.2 (04/07/2025)
 ### Bug Fixes
+* Fix blob garbage accounting for blob direct-write flushes so flush-time filtering and overwrite elision correctly register obsolete blob bytes in blob metadata.
+* Fix a memory accounting leak in IODispatcher where ReadIndex() moved block values out of ReadSet without releasing the associated prefetch memory, causing subsequent prefetches to be blocked when max_prefetch_memory_bytes was set.
+* Fix MultiScan to fall back to synchronous coalesced reads when async I/O is unsupported at runtime.
+
+
+## 11.1.0 (03/23/2026)
+### New Features
+* Add a new option `open_files_async`. The existing behavior is on DB open, we open all sst files and do basic validations. For very large DBs on remote filesystems with many ssts, this may take very long. This option performs these validations instead in the background. Open errors found by this async background task are surfaced as a new background error kAsyncFileOpen.
+* Added `BlockBasedTableOptions::kAuto` index block search type that automatically selects between binary and interpolation search on a per-index-block basis. During SST construction, each index block's key distribution uniformity is analyzed using the coefficient of variation of key gaps, and index blocks with uniform keys use interpolation search while others fall back to binary search. The uniformity threshold is configurable via `BlockBasedTableOptions::uniform_cv_threshold` (default: 0.2).
+* Introduced enforce_write_buffer_manager_during_recovery option to allow WriteBufferManager to be enforced during WAL recovery. (Default: true)
+* Add `memtable_batch_lookup_optimization` option to use batch lookup optimization for memtable MultiGet. For skip list memtables, after each key lookup, the search path is cached and reused for the next key, reducing per-key cost from O(log N) to O(log d) where d is the distance between consecutive keys. Benchmarks show ~7% improvement in memtable-resident MultiGet throughput.
+* Added `BlockBasedTableOptions::PrepopulateBlockCache::kFlushAndCompaction` to prepopulate the block cache during both flush and compaction. Compaction-warmed blocks are inserted at `BOTTOM` priority (vs `LOW` for flush) so they are evicted first under cache pressure. Recommended only for use cases where most or all of the database is expected to reside in cache (e.g., tiered or remote storage where the working set fits in cache).
+* Added new mutable DB option `verify_manifest_content_on_close` (default: false). When enabled, on DB close the MANIFEST file is read back and all records are validated (CRC checksums and logical content). If corruption is detected, a fresh MANIFEST is written from in-memory state.
+
+### Behavior Changes
+* num_reads_sampled now factors in re-seeks and next/prev() on file iterators for files in L1+. next/prev() is discounted by 64x compared to seek due to being a much cheaper call.
+* Remote compaction workers now skip WAL recovery when opening the secondary DB instance, since only the LSM state from MANIFEST is needed for compaction. This reduces I/O and speeds up remote compaction startup.
+
+### Bug Fixes
+* Fix a bug in round-robin compaction that missed selecting input files that are needed to guarantee data correctness and cause crashing in debug builds or silent data corruption in release builds for Get().
+
+## 11.0.0 (02/23/2026)
+### New Features
+* Added support for storing wide-column entity column values in blob files. When `min_blob_size` is configured, large column values in wide-column entities will be stored in blob files, reducing SST file size and improving read performance.
+* Added `CompactionOptionsFIFO::max_data_files_size` to support FIFO compaction trimming based on combined SST and blob file sizes. Added `CompactionOptionsFIFO::use_kv_ratio_compaction` to enable a capacity-derived intra-L0 compaction strategy optimized for BlobDB workloads, producing uniform-sized compacted files for predictable FIFO trimming.
+* Include interpolation search as an alternative to binary search, which typically performs better when keys are uniformly distributed. This is exposed as a new table option `index_block_search_type`. The default is `binary_search`.
+
+### Public API Changes
+* Added new virtual methods `AbortAllCompactions()` and `ResumeAllCompactions()` to the `DB` class. Added new `Status::SubCode::kCompactionAborted` to indicate a compaction was aborted. Added `Status::IsCompactionAborted()` helper method to check if a status represents an aborted compaction.
+* Drop support for reading (and writing) SST files using `BlockBasedTableOptions.format_version` < 2, which hasn't been the default format for about 10 years. An upgrade path is still possible with full compaction using a RocksDB version >= 4.6.0 and < 11.0.0 and then using the newer version.
+* Remove deprecated raw `DB*` variants of `DB::Open` and related functions. Some other minor public APIs were updated as a result
+* Remove deprecated `DB::MaxMemCompactionLevel()`
+* Remove useless option `CompressedSecondaryCacheOptions::compress_format_version`
+* Remove deprecated DB option `skip_checking_sst_file_sizes_on_db_open`. The option was deprecated in 10.5.0 and has been a no-op since then. File size validation is now always performed in parallel during DB open.
+* Remove deprecated `SliceTransform::InRange()` virtual method and the `in_range` callback parameter from `rocksdb_slicetransform_create()` in the C API. `InRange()` was never called by RocksDB and existed only for backward compatibility.
+* Remove deprecated, unused APIs and options: `ReadOptions::managed` and `ColumnFamilyOptions::snap_refresh_nanos`. Corresponding C and Java APIs are also removed.
+* Remove deprecated `SstFileWriter::Add()` method (use `Put()` instead) and the deprecated `skip_filters` parameter from `SstFileWriter` constructors (use `BlockBasedTableOptions::filter_policy` set to `nullptr` to skip filter generation instead).
+
+### Behavior Changes
+* Change the default value of `CompactionOptionsUniversal::reduce_file_locking` from `false` to `true` to improve write stall and reduce read regression
+
+### Bug Fixes
+* Fix longstanding failures that can arise from reading and/or compacting old DB dirs with range deletions (likely from version < 5.19.0) in many newer versions.
+* Fix a bug where WritePrepared/WriteUnprepared TransactionDB with two_write_queues=true could experience "sequence number going backwards" corruption during recovery from a background error, due to allocated-but-not-published sequence numbers not being synced before creating new WAL files.
+
+### Performance Improvements
+* Add a new table option `separate_key_value_in_data_block`. When set to true keys and values will be stored separately in the data block, which can result in higher cpu cache hit rate and better compression. Works best with data blocks with sufficient restart intervals and large values. Previous versions of RocksDB will reject files written using this option.
+
+## 10.11.0 (01/23/2026)
+### Public API Changes
+* New SetOptions API that allows setting options for multiple CFs, avoiding the need to reserialize OPTIONS file for each CF
+* Remove remaining pieces of Lua integration
+
+### Behavior Changes
+* The new default for `BlockBasedTableOptions::format_version` is 7, which has been supported since RocksDB 10.4.0 and is required in order to use CompressionManagers supporting custom compression types.
+
+### Bug Fixes
+* Fixed a small performance bug with `format_version=7` when decompressing formats other than Snappy and ZSTD.
+* Fixed an infinite compaction loop bug with User-Defined Timestamps (UDT) where bottommost files were repeatedly marked for compaction even though their timestamp could not be collapsed.
+* Bugfix for persisted UDT record sequence number zeroing logic.
+
+## 10.10.0 (12/16/2025)
+### Bug Fixes
+* Fixed a bug in best-efforts recovery that causes use-after-free crashes when accessing SST files that were cached during the recovery.
+* Fix resumable compaction incorrectly allowing resumption from a truncated range deletion that is not well handled currently.
+* Fixed a bug in `PosixRandomFileAccess` IO uring submission queue ownership & management. Fix eliminates the false positive 'Bad cqe data' IO errors in `PosixRandomFileAccess::MultiRead` when interleaved with `PosixRandomFileAccess::ReadAsync` on the same thread.
+
+## 10.9.0 (11/21/2025)
+### New Features
+* Added an auto-tuning feature for DB manifest file size that also (by default) improves the safety of existing configurations in case `max_manifest_file_size` is repeatedly exceeded. The new recommendation is to set `max_manifest_file_size` to something small like 1MB and tune `max_manifest_space_amp_pct` as needed to balance write amp and space amp in the manifest. Refer to comments on those options in `DBOptions` for details. Both options are (now) mutable.
+* Added a new API to support option migration for multiple column families
+* Added new option target_file_size_is_upper_bound  that makes most compaction output SST files come close to the target file size without exceeding it, rather than commonly exceeding it by some fraction (current behavior). For now the new behavior is off by default, but we expect to enable it by default in the future.
+* Add a new option allow_trivial_move in CompactionOptions to allow CompactFiles to perform trivial move if possible. By default the flag of allow_trivial_move is false, so it preserve the original behavior.
+
+### Public API Changes
+* To reduce risk of ODR violations or similar, `ROCKSDB_USING_THREAD_STATUS` has been removed from public headers and replaced with static `const bool ThreadStatus::kEnabled`. Some other uses of conditional compilation have been removed from public API headers to reduce risk of ODR violations or other issues.
+
+### Behavior Changes
+* PosixWritableFile now repositions the seek pointer to the new end of file after a call to Truncate.
+* Updated standalone range deletion L0 file compaction behavior to avoid compacting with any newer L0 files (which is expensive and not useful).
+
+### Bug Fixes
+* Fix a bug where compaction with range deletion can persist kTypeMaxValid in MANIFEST as file metadata. kTypeMaxValid is not supposed to be persisted and can change as new value types are introduced. This can cause a forward compatibility issue where older versions of RocksDB don't recognize kTypeMaxValid from newer versions. A new placeholder value type kTypeTruncatedRangeDeletionSentinel is also introduced to replace kTypeMaxValid when reading existing SST files' metadata from MANIFEST. This allows us to strengthen some checks to avoid using kTypeMaxValid in the future.
+* Fixed a bug where `DB::GetSortedWalFiles()` could hang when waiting for a purge operation that found nothing to do (potentially triggered by iterator release, flush, compaction, etc.).
+* Fixed a bug in MultiScan where `max_sequential_skip_in_iterations` could cause the iterator to seek backward to already-unpinned blocks when the same user key spans multiple data blocks, leading to assertion failures or seg fault.
+* Fixed a bug for `WAL_ttl_seconds > 0` use cases where the newest archived WAL files could be incorrectly deleted when the system clock moved backwards.
+
+### Performance Improvements
+* Added optimization that allowed for the asynchronous prefetching of all data outlined in a multiscan iterator. This optimization was applied to the level iterator, which prefetches all data through each of the block-based iterators.
+
+## 10.8.0 (10/21/2025)
+### New Features
+* Add kFSPrefetch to FSSupportedOps enum to allow file systems to indicate prefetch support capability, avoiding unnecessary prefetch system calls on file systems that don't support them.
+* Added experimental support `OpenAndCompactOptions::allow_resumption` for resumable compaction that persists progress during `OpenAndCompact()`, allowing interrupted compactions to resume from the last progress persitence. The default behavior is to not persist progress.
+
+### Public API Changes
+* Allow specifying output temperature in CompactionOptions
+* Added `DB::FlushWAL(const FlushWALOptions&)` as an alternative to `DB::FlushWAL(bool sync)`, where `FlushWALOptions` includes a new `rate_limiter_priority` field (default `Env::IO_TOTAL`) that allows rate limiting and priority passing of manual WAL flush's IO operations.
+* The MultiScan API contract is updated. After a multi scan range got prepared with Prepare API call, the following seeks must seek the start of each prepared scan range in order. In addition, when limit is set, upper bound must be set to the same value of limit before each seek
+
+### Behavior Changes
+* `kChangeTemperature` FIFO compaction will now honor `compaction_target_temp` to all levels regardless of `cf_options::last_level_temperature`
+* Allow UDIs with a non BytewiseComparator
+
+### Bug Fixes
+* Fix incorrect MultiScan seek error status due to bugs in handling range limit falling between adjacent SST files key range.
+* Fix a bug in Page unpinning in MultiScan
+
+### Performance Improvements
+* Fixed a performance regression in LZ4 compression that started in version 10.6.0
+
+## 10.7.0 (09/19/2025)
+### New Features
+* Add the fail_if_no_udi_on_open flag in BlockBasedTableOption to control whether a missing user defined index block in a SST is a hard error or not.
+* A new flag memtable_verify_per_key_checksum_on_seek is added to AdvancedColumnFamilyOptions. When it is enabled, it will validate key checksum along the binary search path on skiplist based memtable during seek operation.
+* Introduce option MultiScanArgs::use_async_io to enable asynchronous I/O during MultiScan, instead of waiting for I/O to be done in Prepare().
+* Add new option `MultiScanArgs::max_prefetch_size` that limits the memory usage of per file pinning of prefetched blocks.
+* Improved `sst_dump` by allowing standalone file and directory arguments without `--file=`. Also added new options and better output for `sst_dump --command=recompress`. See `sst_dump --help`
+
+### Public API Changes
+* HyperClockCache with no `estimated_entry_charge` is now production-ready and is the preferred block cache implementation vs. LRUCache. Please consider updating your code to minimize the risk of hitting performance bottlenecks or anomalies from LRUCache. See cache.h for more detail.
+* RocksDB now requires a C++20 compatible compiler (GCC >= 11, Clang >= 10, Visual Studio >= 2019), including for any code using RocksDB headers.
+* MultiScanArgs used to have a default constructor with default parameter of BytewiseComparator. Now it always requires Comparator in its constructor.
+
+### Behavior Changes
+* The default provided block cache implementation is now HyperClockCache instead of LRUCache, when `block_cache` is nullptr (default) and `no_block_cache==false` (default). We recommend explicitly creating a HyperClockCache block cache based on memory budget and sharing it across all column families and even DB instances. This change could expose previously hidden memory or resource leaks.
+
+### Bug Fixes
+* Reported numbers for compaction and flush CPU usage now include time spent by parallel compression worker threads. This now means compaction/flush CPU usage could exceed the wall clock time.
+* Fix a race condition in FIFO size-based compaction where concurrent threads could select the same non-L0 file, causing assertion failures in debug builds or "Cannot delete table file from LSM tree" errors in release builds.
+* Fix a bug in RocksDB MultiScan with UDI when one of the scan ranges is determined to be empty by the UDI, which causes incorrect results.
+
+### Performance Improvements
+* Add a new table property "rocksdb.key.smallest.seqno" which records the smallest sequence number of all keys in file. It makes ingesting DB generated files faster by
+avoiding scanning the whole file to find the smallest sequence number.
+* Add a new experimental PerKeyPointLockManager to improve efficiency under high lock contention. PointLockManager was not efficient when there is high write contention on same key, as it uses a single conditional variable per lock stripe. PerKeyPointLockManager uses per thread conditional variable supporting fifo order. Although this is an experimental feature. By default, it is disabled. A new boolean flag TransactionDBOptions::use_per_key_point_lock_mgr is added to optionally enable it. Search the flag in code for more info.
+Together, a new configuration TransactionOptions::deadlock_timeout_us is added, which allows the transaction to wait for a short period before perform deadlock detection. When the workload has low lock contention, the deadlock_timeout_us can be configured to be slightly higher than average transaction execution time, so that transaction would likely be able to take the lock before deadlock detection is performed when it is waiting for a lock. This allows transaction to reduce CPU cost on performing deadlock detection, which could be expensive in CPU time. When the workload has high lock contention, the deadlock_timeout_us can be configured to 0, so that transaction would perform deadlock detection immediately. By default the value is 0 to keep the behavior same as before.
+* Majorly improved CPU efficiency and scalability of parallel compression (`CompressionOptions::parallel_threads` > 1), though this efficiency improvement makes parallel compression currently incompatible with UserDefinedIndex and with old setting of `decouple_partitioned_filters=false`. Parallel compression is now considered a production-ready feature. Maximum performance is available with `-DROCKSDB_USE_STD_SEMAPHORES` at compile time, but this is not currently recommended because of reported bugs in implementations of `std::counting_semaphore`/`binary_semaphore`.
+
+## 10.6.0 (08/22/2025)
+### New Features
+* Introduce column family option `cf_allow_ingest_behind`. This option aims to replace `DBOptions::allow_ingest_behind` to enable ingest behind at the per-CF level. `DBOptions::allow_ingest_behind` is deprecated.
+* Introduce `MultiScanArgs::io_coalesce_threshold` to allow a configurable IO coalescing threshold.
+
+### Public API Changes
+* `IngestExternalFileOptions::allow_db_generated_files` now allows files ingestion of any DB generated SST file, instead of only the ones with all keys having sequence number 0.
+* `decouple_partitioned_filters = true` is now the default in BlockBasedTableOptions.
+* GetTtl() API is now available in TTL DB
+* Minimum supported version of LZ4 library is now 1.7.0 (r129 from 2015)
+* Some changes to experimental Compressor and CompressionManager APIs
+* A new Filesystem::SyncFile function is added for syncing a file that was already written, such as on file ingestion. The default implementation matches previous RocksDB behavior: re-open the file for read-write, sync it, and close it. We recommend overriding for FileSystems that do not require syncing for crash recovery or do not handle (well) re-opening for writes.
+
+### Behavior Changes
+* When `allow_ingest_behind` is enabled, compaction will no longer drop tombstones based on the absence of underlying data. Tombstones will be preserved to apply to ingested files.
+
+### Bug Fixes
+* Files in dropped column family won't be returned to the caller upon successful, offline MANIFEST iteration in `GetFileChecksumsFromCurrentManifest`.
+* Fix a bug in MultiScan that causes it to fall back to a normal scan when dictionary compression is enabled.
+* Fix a crash in iterator Prepare() when fill_cache=false
+* Fix a bug in MultiScan where incorrect results can be returned when a Scan's range is across multiple files.
+* Fixed a bug in remote compaction that may mistakenly delete live SST file(s) during the cleanup phase when no keys survive the compaction (all expired)
+* Allow a user defined index to be configured from a string.
+* Make the User Defined Index interface consistently use the user key format, fixing the previous mixed usage of internal and user key.
+
+### Performance Improvements
+* Small improvement to CPU efficiency of compression using built-in algorithms, and a dramatic efficiency improvement for LZ4HC, based on reusing data structures between invocations.
+
+## 10.5.0 (07/18/2025)
+### Public API Changes
+* DB option skip_checking_sst_file_sizes_on_db_open is deprecated, in favor of validating file size in parallel in a thread pool, when db is opened. When DB is opened, with paranoid check enabled, a file with the wrong size would fail the DB open. With paranoid check disabled, the DB open would succeed, the column family with the corrupted file would not be read or write, while the other healthy column families could be read and write normally. When max_open_files option is not set to -1, only a subset of the files will be opened and checked. The rest of the files will be opened and checked when they are accessed.
+
+### Behavior Changes
+* PessimisticTransaction::GetWaitingTxns now returns waiting transaction information even if the current transaction has timed out. This allows the information to be surfaced to users for debugging purposes once it is known that the timeout has occurred.
+* A new API GetFileSize is added to FSRandomAccessFile interface class. It uses fstat vs stat on the posix implementation which is more efficient. Caller could use it to get file size faster. This function might be required in the future for FileSystem implementation outside of the RocksDB code base.
+* RocksDB now triggers eligible compactions every 12 hours when periodic compaction is configured. This solves a limitation of the compaction trigger mechanism, which would only trigger compaction after specific events like flush, compaction, or SetOptions.
+
+### Bug Fixes
+* Fix a bug in BackupEngine that can crash backup due to a null FSWritableFile passed to WritableFileWriter.
+* Fix DB::NewMultiScan iterator to respect the scan upper bound specified in ScanOptions
+
+### Performance Improvements
+* Optimized MultiScan using BlockBasedTable to coalesce I/Os and prefetch all data blocks.
+
+## 10.4.0 (06/20/2025)
+### New Features
+* Add a new CF option `memtable_avg_op_scan_flush_trigger` that supports triggering memtable flush when an iterator scans through an expensive range of keys, with the average number of skipped keys from the active memtable exceeding the threshold.
+* Vector based memtable now supports concurrent writers (DBOptions::allow_concurrent_memtable_write) #13675.
+* Add new experimental `TransactionOptions::large_txn_commit_optimize_byte_threshold` to enable optimizations for large transaction commit by transaction batch data size.
+* Add a new option `CompactionOptionsUniversal::reduce_file_locking` and if it's true, auto universal compaction picking will adjust to minimize locking of input files when bottom priority compactions are waiting to run. This can increase the likelihood of existing L0s being selected for compaction, thereby improving write stall and reducing read regression.
+* Add new `format_version=7` to aid experimental support of custom compression algorithms with CompressionManager and block-based table. This format version includes changing the format of `TableProperties::compression_name`.
+
+### Public API Changes
+* Change NewExternalTableFactory to return a unique_ptr instead of shared_ptr.
+* Add an optional min file size requirement for deletion triggered compaction. It can be specified when creating `CompactOnDeletionCollectorFactory`.
+
+### Behavior Changes
+* `TransactionOptions::large_txn_commit_optimize_threshold` now has default value 0 for disabled. `TransactionDBOptions::txn_commit_bypass_memtable_threshold` now has no effect on transactions.
+
+### Bug Fixes
+* Fix a bug where CreateColumnFamilyWithImport() could miss the SST file for the memtable flush it triggered. The exported CF then may not contain the updates in the memtable when CreateColumnFamilyWithImport() is called.
+* Fix iterator operations returning NotImplemented status if disallow_memtable_writes and paranoid_memory_checks CF options are both set.
+* Fixed handling of file checksums in IngestExternalFile() to allow providing checksums using recognized but not necessarily the DB's preferred checksum function, to ease migration between checksum functions.
+
+## 10.3.0 (05/17/2025)
+### New Features
+* Add new experimental `CompactionOptionsFIFO::allow_trivial_copy_when_change_temperature` along with `CompactionOptionsFIFO::trivial_copy_buffer_size` to allow optimizing FIFO compactions with tiering when kChangeTemperature to move files from source tier FileSystem to another tier FileSystem via trivial and direct copying raw sst file instead of reading thru the content of the SST file then rebuilding the table files.
+* Add a new field to Compaction Stats in LOG files for the pre-compression size written to each level.
+* Add new experimental `TransactionOptions::large_txn_commit_optimize_threshold` to enable optimizations for large transaction commit with per transaction threshold. `TransactionDBOptions::txn_commit_bypass_memtable_threshold` is deprecated in favor of this transaction option.
+* [internal team use only] Allow an application-defined `request_id` to be passed to RocksDB and propagated to the filesystem via IODebugContext
+
+### Bug Fixes
+* Fix a bug where transaction lock upgrade can incorrectly fail with a Deadlock status. This happens when a transaction has a non-zero timeout and tries to upgrade a shared lock that is also held by another transaction.
+* Pass wrapped WritableFileWriter pointer to ExternalTableBuilder so that the file checksum can be correctly calculated and returned by SstFileWriter for external table files.
+* Fix an infinite-loop bug in transaction locking. This can happen if a transaction reaches lock limit and its time out expires before it attempts to wait for it.
+* Fixed a potential data race with `CompressionOptions::parallel_threads > 1` and a `TablePropertiesCollector` overriding `BlockAdd()`.
+
+## 10.2.0 (04/21/2025)
+### New Features
+* Provide histogram stats `COMPACTION_PREFETCH_BYTES` to measure number of bytes for RocksDB's prefetching (as opposed to file
+system's prefetch) on SST file during compaction read
+* A new API DB::GetNewestUserDefinedTimestamp is added to return the newest user defined timestamp seen in a column family
+* Introduce API `IngestWriteBatchWithIndex()` for ingesting updates into DB while bypassing memtable writes. This improves performance when writing a large write batch to the DB.
+* Add a new CF option `memtable_op_scan_flush_trigger` that triggers a flush of the memtable if an iterator's Seek()/Next() scans over a certain number of invisible entries from the memtable.
+
+### Public API Changes
+* AdvancedColumnFamilyOptions.max_write_buffer_number_to_maintain is deleted. It's deprecated since introduction of a better option max_write_buffer_size_to_maintain since RocksDB 6.5.0.
+* Deprecated API `DB::MaxMemCompactionLevel()`.
+* Deprecated `ReadOptions::ignore_range_deletions`.
+* Deprecated API `experimental::PromoteL0()`.
+* Added arbitrary string map for additional options to be overridden for remote compactions
+* The fail_if_options_file_error option in DBOptions has been removed. The behavior now is to always return failure in any API that fails to persist the OPTIONS file.
+
+### Behavior Changes
+* Make stats `PREFETCH_BYTES_USEFUL`, `PREFETCH_HITS`, `PREFETCH_BYTES` only account for prefetching during user initiated scan
+
+### Bug Fixes
+* Fix a bug in Posix file system that the FSWritableFile created via `FileSystem::ReopenWritableFile` internally does not track the correct file size.
 * Fix a bug where tail size of remote compaction output is not persisted in primary db's manifest
 
 ## 10.1.0 (03/24/2025)
@@ -149,7 +396,7 @@
 * In FIFO compaction, compactions for changing file temperature (configured by option `file_temperature_age_thresholds`) will compact one file at a time, instead of merging multiple eligible file together (#13018).
 * Support ingesting db generated files using hard link, i.e. IngestExternalFileOptions::move_files/link_files and IngestExternalFileOptions::allow_db_generated_files.
 * Add a new file ingestion option `IngestExternalFileOptions::link_files` to hard link input files and preserve original files links after ingestion.
-* DB::Close now untracks files in SstFileManager, making avaialble any space used
+* DB::Close now untracks files in SstFileManager, making available any space used
 by them. Prior to this change they would be orphaned until the DB is re-opened.
 
 ### Bug Fixes
@@ -345,7 +592,7 @@ MultiGetBenchmarks.multiGetList10 no_column_family 10000 16 100 1024 thrpt 25 76
 * Removed deprecated option `ColumnFamilyOptions::check_flush_compaction_key_order`
 * Remove the default `WritableFile::GetFileSize` and `FSWritableFile::GetFileSize` implementation that returns 0 and make it pure virtual, so that subclasses are enforced to explicitly provide an implementation.
 * Removed deprecated option `ColumnFamilyOptions::level_compaction_dynamic_file_size`
-* Removed tickers with typos "rocksdb.error.handler.bg.errro.count", "rocksdb.error.handler.bg.io.errro.count", "rocksdb.error.handler.bg.retryable.io.errro.count".
+* Removed tickers with typos "rocksdb.error.handler.bg.error.count", "rocksdb.error.handler.bg.io.error.count", "rocksdb.error.handler.bg.retryable.io.error.count".
 * Remove the force mode for `EnableFileDeletions` API because it is unsafe with no known legitimate use.
 * Removed deprecated option `ColumnFamilyOptions::ignore_max_compaction_bytes_for_input`
 * `sst_dump --command=check` now compares the number of records in a table with `num_entries` in table property, and reports corruption if there is a mismatch. API `SstFileDumper::ReadSequential()` is updated to optionally do this verification. (#12322)
@@ -372,7 +619,7 @@ MultiGetBenchmarks.multiGetList10 no_column_family 10000 16 100 1024 thrpt 25 76
 * Exposed options ttl via c api.
 
 ### Behavior Changes
-* `rocksdb.blobdb.blob.file.write.micros` expands to also measure time writing the header and footer. Therefore the COUNT may be higher and values may be smaller than before. For stacked BlobDB, it no longer measures the time of explictly flushing blob file.
+* `rocksdb.blobdb.blob.file.write.micros` expands to also measure time writing the header and footer. Therefore the COUNT may be higher and values may be smaller than before. For stacked BlobDB, it no longer measures the time of explicitly flushing blob file.
 * Files will be compacted to the next level if the data age exceeds periodic_compaction_seconds except for the last level.
 * Reduced the compaction debt ratio trigger for scheduling parallel compactions
 * For leveled compaction with default compaction pri (kMinOverlappingRatio), files marked for compaction will be prioritized over files not marked when picking a file from a level for compaction.
@@ -437,7 +684,7 @@ want to continue to use force enabling, they need to explicitly pass a `true` to
 
 ### Behavior Changes
 * During off-peak hours defined by `daily_offpeak_time_utc`, the compaction picker will select a larger number of files for periodic compaction. This selection will include files that are projected to expire by the next off-peak start time, ensuring that these files are not chosen for periodic compaction outside of off-peak hours.
-* If an error occurs when writing to a trace file after `DB::StartTrace()`, the subsequent trace writes are skipped to avoid writing to a file that has previously seen error. In this case, `DB::EndTrace()` will also return a non-ok status with info about the error occured previously in its status message.
+* If an error occurs when writing to a trace file after `DB::StartTrace()`, the subsequent trace writes are skipped to avoid writing to a file that has previously seen error. In this case, `DB::EndTrace()` will also return a non-ok status with info about the error occurred previously in its status message.
 * Deleting stale files upon recovery are delegated to SstFileManger if available so they can be rate limited.
 * Make RocksDB only call `TablePropertiesCollector::Finish()` once.
 * When `WAL_ttl_seconds > 0`, we now process archived WALs for deletion at least every `WAL_ttl_seconds / 2` seconds. Previously it could be less frequent in case of small `WAL_ttl_seconds` values when size-based expiration (`WAL_size_limit_MB > 0 `) was simultaneously enabled.
@@ -1225,7 +1472,7 @@ Note: The next release will be major release 7.0. See https://github.com/faceboo
 ### Public API change
 * Extend WriteBatch::AssignTimestamp and AssignTimestamps API so that both functions can accept an optional `checker` argument that performs additional checking on timestamp sizes.
 * Introduce a new EventListener callback that will be called upon the end of automatic error recovery.
-* Add IncreaseFullHistoryTsLow API so users can advance each column family's full_history_ts_low seperately.
+* Add IncreaseFullHistoryTsLow API so users can advance each column family's full_history_ts_low separately.
 * Add GetFullHistoryTsLow API so users can query current full_history_low value of specified column family.
 
 ### Performance Improvements

INSTALL.md

@@ -6,7 +6,7 @@ than release mode.
 
 RocksDB's library should be able to compile without any dependency installed,
 although we recommend installing some compression libraries (see below).
-We do depend on newer gcc/clang with C++17 support (GCC >= 7, Clang >= 5).
+We do depend on newer gcc/clang with C++20 support (GCC >= 11, Clang >= 10).
 
 There are few options when compiling RocksDB:
 
@@ -60,7 +60,7 @@ most processors made since roughly 2013.
 ## Supported platforms
 
 * **Linux - Ubuntu**
-    * Upgrade your gcc to version at least 7 to get C++17 support.
+    * Upgrade your gcc to version at least 11 to get C++20 support.
     * Install gflags. First, try: `sudo apt-get install libgflags-dev`
       If this doesn't work and you're using Ubuntu, here's a nice tutorial:
       (http://askubuntu.com/questions/312173/installing-gflags-12-04)
@@ -72,7 +72,7 @@ most processors made since roughly 2013.
     * Install zstandard: `sudo apt-get install libzstd-dev`.
 
 * **Linux - CentOS / RHEL**
-    * Upgrade your gcc to version at least 7 to get C++17 support
+    * Upgrade your gcc to version at least 11 to get C++20 support
     * Install gflags:
 
               git clone https://github.com/gflags/gflags.git
@@ -122,7 +122,7 @@ most processors made since roughly 2013.
               make && sudo make install
 
 * **OS X**:
-    * Install latest C++ compiler that supports C++ 17:
+    * Install latest C++ compiler that supports C++20:
         * Update XCode:  run `xcode-select --install` (or install it from XCode App's settting).
         * Install via [homebrew](http://brew.sh/).
             * If you're first time developer in MacOS, you still need to run: `xcode-select --install` in your command line.
@@ -213,7 +213,7 @@ most processors made since roughly 2013.
              export PATH=/opt/freeware/bin:$PATH
 
 * **Solaris Sparc**
-    * Install GCC 7 and higher.
+    * Install GCC 11 and higher.
     * Use these environment variables:
 
              export CC=gcc

Makefile

@@ -148,10 +148,8 @@ ifeq ($(USE_COROUTINES), 1)
 	USE_FOLLY = 1
 	# glog/logging.h requires HAVE_CXX11_ATOMIC
 	OPT += -DUSE_COROUTINES -DHAVE_CXX11_ATOMIC
-	ROCKSDB_CXX_STANDARD = c++2a
 	USE_RTTI = 1
 ifneq ($(USE_CLANG), 1)
-	ROCKSDB_CXX_STANDARD = c++20
 	PLATFORM_CXXFLAGS += -fcoroutines
 endif
 endif
@@ -298,6 +296,28 @@ $(info $(shell $(CC) --version))
 $(info $(shell $(CXX) --version))
 endif
 
+# ccache support
+# Set USE_CCACHE=1 to enable ccache, or let it auto-detect
+ifndef USE_CCACHE
+  CCACHE := $(shell which ccache 2>/dev/null)
+  ifneq ($(CCACHE),)
+    USE_CCACHE := 1
+  else
+    USE_CCACHE := 0
+  endif
+endif
+
+ifeq ($(USE_CCACHE), 1)
+  CCACHE := $(shell which ccache 2>/dev/null)
+  ifneq ($(CCACHE),)
+    $(info Using ccache: $(CCACHE))
+    CC := $(CCACHE) $(CC)
+    CXX := $(CCACHE) $(CXX)
+  else
+    $(warning ccache requested but not found in PATH)
+  endif
+endif
+
 missing_make_config_paths := $(shell				\
 	grep "\./\S*\|/\S*" -o $(CURDIR)/make_config.mk | 	\
 	while read path;					\
@@ -364,14 +384,16 @@ endif
 # TSAN doesn't work well with jemalloc. If we're compiling with TSAN, we should use regular malloc.
 ifdef COMPILE_WITH_TSAN
 	DISABLE_JEMALLOC=1
+	# Use a suppressions file instead of the process-wide TSAN default
+	# suppressions hook, which belongs to the final application.
+	TSAN_OPTIONS?=suppressions=$(CURDIR)/tools/tsan_suppressions.txt
+	export TSAN_OPTIONS
 	EXEC_LDFLAGS += -fsanitize=thread
 	PLATFORM_CCFLAGS += -fsanitize=thread -fPIC -DFOLLY_SANITIZE_THREAD
 	PLATFORM_CXXFLAGS += -fsanitize=thread -fPIC -DFOLLY_SANITIZE_THREAD
         # Turn off -pg when enabling TSAN testing, because that induces
         # a link failure.  TODO: find the root cause
 	PROFILING_FLAGS =
-	# LUA is not supported under TSAN
-	LUA_PATH =
 	# Limit keys for crash test under TSAN to avoid error:
 	# "ThreadSanitizer: DenseSlabAllocator overflow. Dying."
 	CRASH_TEST_EXT_ARGS += --max_key=1000000
@@ -432,7 +454,7 @@ ifndef USE_FOLLY
 endif
 
 ifndef GTEST_THROW_ON_FAILURE
-	export GTEST_THROW_ON_FAILURE=1
+	export GTEST_THROW_ON_FAILURE=0
 endif
 ifndef GTEST_HAS_EXCEPTIONS
 	export GTEST_HAS_EXCEPTIONS=1
@@ -448,83 +470,7 @@ else
 	PLATFORM_CXXFLAGS += -isystem $(GTEST_DIR)
 endif
 
-# This provides a Makefile simulation of a Meta-internal folly integration.
-# It is not validated for general use.
-#
-# USE_FOLLY links the build targets with libfolly.a. The latter could be
-# built using 'make build_folly', or built externally and specified in
-# the CXXFLAGS and EXTRA_LDFLAGS env variables. The build_detect_platform
-# script tries to detect if an external folly dependency has been specified.
-# If not, it exports FOLLY_PATH to the path of the installed Folly and
-# dependency libraries.
-#
-# USE_FOLLY_LITE cherry picks source files from Folly to include in the
-# RocksDB library. Its faster and has fewer dependencies on 3rd party
-# libraries, but with limited functionality. For example, coroutine
-# functionality is not available.
-ifeq ($(USE_FOLLY),1)
-ifeq ($(USE_FOLLY_LITE),1)
-$(error Please specify only one of USE_FOLLY and USE_FOLLY_LITE)
-endif
-ifneq ($(strip $(FOLLY_PATH)),)
-	BOOST_PATH = $(shell (ls -d $(FOLLY_PATH)/../boost*))
-	DBL_CONV_PATH = $(shell (ls -d $(FOLLY_PATH)/../double-conversion*))
-	GFLAGS_PATH = $(shell (ls -d $(FOLLY_PATH)/../gflags*))
-	GLOG_PATH = $(shell (ls -d $(FOLLY_PATH)/../glog*))
-	LIBEVENT_PATH = $(shell (ls -d $(FOLLY_PATH)/../libevent*))
-	XZ_PATH = $(shell (ls -d $(FOLLY_PATH)/../xz*))
-	LIBSODIUM_PATH = $(shell (ls -d $(FOLLY_PATH)/../libsodium*))
-	FMT_PATH = $(shell (ls -d $(FOLLY_PATH)/../fmt*))
-
-	# For some reason, glog and fmt libraries are under either lib or lib64
-	GLOG_LIB_PATH = $(shell (ls -d $(GLOG_PATH)/lib*))
-	FMT_LIB_PATH = $(shell (ls -d $(FMT_PATH)/lib*))
-
-	# AIX: pre-defined system headers are surrounded by an extern "C" block
-	ifeq ($(PLATFORM), OS_AIX)
-		PLATFORM_CCFLAGS += -I$(BOOST_PATH)/include -I$(DBL_CONV_PATH)/include -I$(GLOG_PATH)/include -I$(LIBEVENT_PATH)/include -I$(XZ_PATH)/include -I$(LIBSODIUM_PATH)/include -I$(FOLLY_PATH)/include -I$(FMT_PATH)/include
-		PLATFORM_CXXFLAGS += -I$(BOOST_PATH)/include -I$(DBL_CONV_PATH)/include -I$(GLOG_PATH)/include -I$(LIBEVENT_PATH)/include -I$(XZ_PATH)/include -I$(LIBSODIUM_PATH)/include -I$(FOLLY_PATH)/include -I$(FMT_PATH)/include
-	else
-		PLATFORM_CCFLAGS += -isystem $(BOOST_PATH)/include -isystem $(DBL_CONV_PATH)/include -isystem $(GLOG_PATH)/include -isystem $(LIBEVENT_PATH)/include -isystem $(XZ_PATH)/include -isystem $(LIBSODIUM_PATH)/include -isystem $(FOLLY_PATH)/include -isystem $(FMT_PATH)/include
-		PLATFORM_CXXFLAGS += -isystem $(BOOST_PATH)/include -isystem $(DBL_CONV_PATH)/include -isystem $(GLOG_PATH)/include -isystem $(LIBEVENT_PATH)/include -isystem $(XZ_PATH)/include -isystem $(LIBSODIUM_PATH)/include -isystem $(FOLLY_PATH)/include -isystem $(FMT_PATH)/include
-	endif
-
-	# Add -ldl at the end as gcc resolves a symbol in a library by searching only in libraries specified later
-	# in the command line
-	PLATFORM_LDFLAGS += $(FOLLY_PATH)/lib/libfolly.a $(BOOST_PATH)/lib/libboost_context.a $(BOOST_PATH)/lib/libboost_filesystem.a $(BOOST_PATH)/lib/libboost_atomic.a $(BOOST_PATH)/lib/libboost_program_options.a $(BOOST_PATH)/lib/libboost_regex.a $(BOOST_PATH)/lib/libboost_system.a $(BOOST_PATH)/lib/libboost_thread.a $(DBL_CONV_PATH)/lib/libdouble-conversion.a $(FMT_LIB_PATH)/libfmt.a $(GLOG_LIB_PATH)/libglog.so $(GFLAGS_PATH)/lib/libgflags.so.2.2 $(LIBEVENT_PATH)/lib/libevent-2.1.so -ldl
-	PLATFORM_LDFLAGS += -Wl,-rpath=$(GFLAGS_PATH)/lib -Wl,-rpath=$(GLOG_LIB_PATH) -Wl,-rpath=$(LIBEVENT_PATH)/lib -Wl,-rpath=$(LIBSODIUM_PATH)/lib -Wl,-rpath=$(LIBEVENT_PATH)/lib
-endif
-	PLATFORM_CCFLAGS += -DUSE_FOLLY -DFOLLY_NO_CONFIG
-	PLATFORM_CXXFLAGS += -DUSE_FOLLY -DFOLLY_NO_CONFIG
-endif
-
-ifeq ($(USE_FOLLY_LITE),1)
-	# Path to the Folly source code and include files
-	FOLLY_DIR = ./third-party/folly
-ifneq ($(strip $(BOOST_SOURCE_PATH)),)
-	BOOST_INCLUDE = $(shell (ls -d $(BOOST_SOURCE_PATH)/boost*/))
-	# AIX: pre-defined system headers are surrounded by an extern "C" block
-	ifeq ($(PLATFORM), OS_AIX)
-		PLATFORM_CCFLAGS += -I$(BOOST_INCLUDE)
-		PLATFORM_CXXFLAGS += -I$(BOOST_INCLUDE)
-	else
-		PLATFORM_CCFLAGS += -isystem $(BOOST_INCLUDE)
-		PLATFORM_CXXFLAGS += -isystem $(BOOST_INCLUDE)
-	endif
-endif  # BOOST_SOURCE_PATH
-	# AIX: pre-defined system headers are surrounded by an extern "C" block
-	ifeq ($(PLATFORM), OS_AIX)
-		PLATFORM_CCFLAGS += -I$(FOLLY_DIR)
-		PLATFORM_CXXFLAGS += -I$(FOLLY_DIR)
-	else
-		PLATFORM_CCFLAGS += -isystem $(FOLLY_DIR)
-		PLATFORM_CXXFLAGS += -isystem $(FOLLY_DIR)
-	endif
-	PLATFORM_CCFLAGS += -DUSE_FOLLY -DFOLLY_NO_CONFIG
-	PLATFORM_CXXFLAGS += -DUSE_FOLLY -DFOLLY_NO_CONFIG
-# TODO: fix linking with fbcode compiler config
-	PLATFORM_LDFLAGS += -lglog
-endif
+include folly.mk
 
 ifdef TEST_CACHE_LINE_SIZE
   PLATFORM_CCFLAGS += -DTEST_CACHE_LINE_SIZE=$(TEST_CACHE_LINE_SIZE)
@@ -564,32 +510,6 @@ ifndef DISABLE_WARNING_AS_ERROR
 endif
 
 
-ifdef LUA_PATH
-
-ifndef LUA_INCLUDE
-LUA_INCLUDE=$(LUA_PATH)/include
-endif
-
-LUA_INCLUDE_FILE=$(LUA_INCLUDE)/lualib.h
-
-ifeq ("$(wildcard $(LUA_INCLUDE_FILE))", "")
-# LUA_INCLUDE_FILE does not exist
-$(error Cannot find lualib.h under $(LUA_INCLUDE).  Try to specify both LUA_PATH and LUA_INCLUDE manually)
-endif
-LUA_FLAGS = -I$(LUA_INCLUDE) -DLUA -DLUA_COMPAT_ALL
-CFLAGS += $(LUA_FLAGS)
-CXXFLAGS += $(LUA_FLAGS)
-
-ifndef LUA_LIB
-LUA_LIB = $(LUA_PATH)/lib/liblua.a
-endif
-ifeq ("$(wildcard $(LUA_LIB))", "") # LUA_LIB does not exist
-$(error $(LUA_LIB) does not exist.  Try to specify both LUA_PATH and LUA_LIB manually)
-endif
-EXEC_LDFLAGS += $(LUA_LIB)
-
-endif
-
 ifeq ($(NO_THREEWAY_CRC32C), 1)
 	CXXFLAGS += -DNO_THREEWAY_CRC32C
 endif
@@ -638,13 +558,14 @@ endif
 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))
+POINT_LOCK_BENCH_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(POINT_LOCK_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) $(CACHE_BENCH_LIB_SOURCES) $(ANALYZER_LIB_SOURCES) $(STRESS_LIB_SOURCES)
+ALL_SOURCES += $(TOOL_LIB_SOURCES) $(BENCH_LIB_SOURCES) $(CACHE_BENCH_LIB_SOURCES) $(POINT_LOCK_BENCH_LIB_SOURCES) $(ANALYZER_LIB_SOURCES) $(STRESS_LIB_SOURCES)
 ALL_SOURCES += $(TEST_MAIN_SOURCES) $(TOOL_MAIN_SOURCES) $(BENCH_MAIN_SOURCES)
 ALL_SOURCES += $(ROCKSDB_PLUGIN_SOURCES) $(ROCKSDB_PLUGIN_TESTS)
 
@@ -659,8 +580,8 @@ ifneq ($(filter check-headers, $(MAKECMDGOALS)),)
 # TODO: add/support JNI headers
 	DEV_HEADER_DIRS := $(sort include/ $(dir $(ALL_SOURCES)))
 # Some headers like in port/ are platform-specific
-	DEV_HEADERS_TO_CHECK := $(shell $(FIND) $(DEV_HEADER_DIRS) -type f -name '*.h' | grep -E -v 'port/|plugin/|lua/|range_tree/|secondary_index/')
-	PUBLIC_HEADERS_TO_CHECK := $(shell $(FIND) include/ -type f -name '*.h' | grep -E -v 'lua/')
+	DEV_HEADERS_TO_CHECK := $(shell $(FIND) $(DEV_HEADER_DIRS) -type f -name '*.h' | grep -E -v 'port/|plugin/|range_tree/|secondary_index/')
+	PUBLIC_HEADERS_TO_CHECK := $(shell $(FIND) include/ -type f -name '*.h')
 else
 	DEV_HEADERS_TO_CHECK :=
 	PUBLIC_HEADERS_TO_CHECK :=
@@ -683,7 +604,8 @@ am__v_CCH_1 =
 # user build settings
 %.h.pub: %.h # .h.pub not actually created, so re-checked on each invocation
 	$(AM_V_CCH) cd include/ && echo '#include "$(patsubst include/%,%,$<)"' | \
-	  $(CXX) -I. -DROCKSDB_NAMESPACE=42 -x c++ -c - -o /dev/null
+	  $(CXX) -std=$(or $(ROCKSDB_CXX_STANDARD),c++20) -I. -DROCKSDB_NAMESPACE=42 -x c++ -c - -o /dev/null
+	build_tools/check-public-header.sh $<
 
 check-headers: $(HEADER_OK_FILES)
 
@@ -703,25 +625,24 @@ endif
 
 ROCKSDBTESTS_SUBSET ?= $(TESTS)
 
-# c_test - doesn't use gtest
-# env_test - suspicious use of test::TmpDir
-# deletefile_test - serial because it generates giant temporary files in
-#   its various tests. Parallel can fill up your /dev/shm
-# db_bloom_filter_test - serial because excessive space usage by instances
-#   of DBFilterConstructionReserveMemoryTestWithParam can fill up /dev/shm
+# c_test - doesn't use gtest, can't be sharded
+# Other tests previously listed here (backup_engine_test, db_bloom_filter_test,
+# perf_context_test, etc.) were NON_PARALLEL due to /dev/shm memory concerns
+# when the old per-test-case sharding spawned thousands of processes. With the
+# new gtest-based sharding (GTEST_SHARD_SIZE=10, max NCORES*8 shards), at most
+# ~4 shards run concurrently on CI (4 cores), so peak memory is manageable
+# (4 * 1GB = 4GB << 16GB shm).
 NON_PARALLEL_TEST = \
 	c_test \
-	env_test \
-	deletefile_test \
-	db_bloom_filter_test \
 	$(PLUGIN_TESTS) \
 
-PARALLEL_TEST = $(filter-out $(NON_PARALLEL_TEST), $(TESTS))
+PARALLEL_TEST = $(filter-out $(NON_PARALLEL_TEST), $(ROCKSDBTESTS_SUBSET))
 
 # Not necessarily well thought out or up-to-date, but matches old list
 TESTS_PLATFORM_DEPENDENT := \
 	db_basic_test \
 	db_blob_basic_test \
+	db_blob_direct_write_test \
 	db_encryption_test \
 	external_sst_file_basic_test \
 	auto_roll_logger_test \
@@ -729,6 +650,7 @@ TESTS_PLATFORM_DEPENDENT := \
 	dynamic_bloom_test \
 	c_test \
 	checkpoint_test \
+	sorted_run_builder_test \
 	crc32c_test \
 	coding_test \
 	inlineskiplist_test \
@@ -887,9 +809,20 @@ endif  # PLATFORM_SHARED_EXT
 .PHONY: check clean coverage ldb_tests package dbg gen-pc build_size \
 	release tags tags0 valgrind_check format static_lib shared_lib all \
 	rocksdbjavastatic rocksdbjava install install-static install-shared \
-	uninstall analyze tools tools_lib check-headers checkout_folly
+	uninstall analyze tools tools_lib check-headers checkout_folly clang-tidy
 
-all: $(LIBRARY) $(BENCHMARKS) tools tools_lib test_libs $(TESTS)
+# Auto-configure git hooks on first build so developers do not need to run
+# "make install-hooks" manually. This is a no-op if already set.
+setup-hooks:
+	@if [ -d .git ] && [ -d githooks ]; then \
+		cur=$$(git config core.hooksPath 2>/dev/null); \
+		if [ "$$cur" != "githooks" ]; then \
+			git config core.hooksPath githooks; \
+			echo "git hooks: configured core.hooksPath = githooks"; \
+		fi; \
+	fi
+
+all: setup-hooks $(LIBRARY) $(BENCHMARKS) tools tools_lib test_libs $(TESTS)
 
 all_but_some_tests: $(LIBRARY) $(BENCHMARKS) tools tools_lib test_libs $(ROCKSDBTESTS_SUBSET)
 
@@ -953,21 +886,42 @@ coverage: clean
 
 parallel_tests = $(patsubst %,parallel_%,$(PARALLEL_TEST))
 .PHONY: gen_parallel_tests $(parallel_tests)
+# Shard size controls how many test cases run per process. The actual number
+# of shards per binary is: min(ceil(test_count / GTEST_SHARD_SIZE), NCORES * 8)
+# This adapts to machine size: many small shards on beefy machines, fewer
+# larger shards on CI (typically 2-4 cores).
+GTEST_SHARD_SIZE ?= 10
+NCORES ?= $(shell nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)
+
 $(parallel_tests):
 	$(AM_V_at)TEST_BINARY=$(patsubst parallel_%,%,$@); \
-  TEST_NAMES=` \
-    (./$$TEST_BINARY --gtest_list_tests || echo "  $${TEST_BINARY}__list_tests_failure") \
-    | awk '/^[^ ]/ { prefix = $$1 } /^[ ]/ { print prefix $$1 }'`; \
-	echo "  Generating parallel test scripts for $$TEST_BINARY"; \
-	for TEST_NAME in $$TEST_NAMES; do \
-		TEST_SCRIPT=t/run-$$TEST_BINARY-$${TEST_NAME//\//-}; \
+  TEST_COUNT=` \
+    (./$$TEST_BINARY --gtest_list_tests 2>/dev/null || echo "  list_failure") \
+    | grep -c '^ '`; \
+	if [ "$$TEST_COUNT" -le 0 ]; then TEST_COUNT=1; fi; \
+	MAX_SHARDS=$$(( $(NCORES) * 8 )); \
+	NUM_SHARDS=$$(( (TEST_COUNT + $(GTEST_SHARD_SIZE) - 1) / $(GTEST_SHARD_SIZE) )); \
+	if [ "$$NUM_SHARDS" -gt "$$MAX_SHARDS" ]; then NUM_SHARDS=$$MAX_SHARDS; fi; \
+	if [ "$$NUM_SHARDS" -le 0 ]; then NUM_SHARDS=1; fi; \
+	echo "  Generating $$NUM_SHARDS shards for $$TEST_BINARY ($$TEST_COUNT tests)"; \
+	SHARD_IDX=0; \
+	while [ "$$SHARD_IDX" -lt "$$NUM_SHARDS" ]; do \
+		if [ -n "$(CI_TOTAL_SHARDS)" ] && [ $$(( $$SHARD_IDX % $(CI_TOTAL_SHARDS) )) -ne $(CI_SHARD_INDEX) ]; then \
+			SHARD_IDX=$$((SHARD_IDX + 1)); \
+			continue; \
+		fi; \
+		TEST_SCRIPT=t/run-$$TEST_BINARY-shard-$$SHARD_IDX; \
     printf '%s\n' \
       '#!/bin/sh' \
       "d=\$(TEST_TMPDIR)$$TEST_SCRIPT" \
       'mkdir -p $$d' \
-      "TEST_TMPDIR=\$$d $(DRIVER) ./$$TEST_BINARY --gtest_filter=$$TEST_NAME" \
+      "TEST_TMPDIR=\$$d GTEST_TOTAL_SHARDS=$$NUM_SHARDS GTEST_SHARD_INDEX=$$SHARD_IDX $(DRIVER) ./$$TEST_BINARY" \
+      'test_retcode=$$?' \
+      '[ $$test_retcode -eq 0 ] && rm -rf $$d' \
+      'exit $$test_retcode' \
 		> $$TEST_SCRIPT; \
 		chmod a=rx $$TEST_SCRIPT; \
+		SHARD_IDX=$$((SHARD_IDX + 1)); \
 	done
 
 gen_parallel_tests:
@@ -991,8 +945,10 @@ gen_parallel_tests:
 # 152.120 PASS t/DBTest.FileCreationRandomFailure
 # 107.816 PASS t/DBTest.EncodeDecompressedBlockSizeTest
 #
+# With sharded test execution, prioritize binaries known to be slow.
+# These generate many shards and should start early for good load balancing.
 slow_test_regexp = \
-	^.*MySQLStyleTransactionTest.*$$|^.*SnapshotConcurrentAccessTest.*$$|^.*SeqAdvanceConcurrentTest.*$$|^t/run-table_test-HarnessTest.Randomized$$|^t/run-db_test-.*(?:FileCreationRandomFailure|EncodeDecompressedBlockSizeTest)$$|^.*RecoverFromCorruptedWALWithoutFlush$$
+	^.*block_based_table_reader_test.*$$|^.*table_test.*$$|^.*block_test.*$$|^.*write_prepared_transaction_test.*$$|^.*transaction_test.*$$|^.*external_sst_file_test.*$$|^.*db_wal_test.*$$|^.*db_with_timestamp_basic_test.*$$|^.*db_test-.*$$
 prioritize_long_running_tests =						\
   perl -pe 's,($(slow_test_regexp)),100 $$1,'				\
     | sort -k1,1gr							\
@@ -1027,7 +983,13 @@ check_0:
 	  'To monitor subtest <duration,pass/fail,name>,'		\
 	  '  run "make watch-log" in a separate window' '';		\
 	{ \
-		printf './%s\n' $(filter-out $(PARALLEL_TEST),$(TESTS)); \
+		NON_PARALLEL_LIST="$(filter-out $(PARALLEL_TEST),$(ROCKSDBTESTS_SUBSET))"; \
+		if [ -n "$$NON_PARALLEL_LIST" ]; then \
+		  printf './%s\n' $$NON_PARALLEL_LIST \
+		    | if [ -n "$(CI_TOTAL_SHARDS)" ]; then \
+		        awk -v s=$(CI_SHARD_INDEX) -v n=$(CI_TOTAL_SHARDS) '(NR-1)%n==s'; \
+		      else cat; fi; \
+		fi; \
 		find t -name 'run-*' -print; \
 	} \
 	  | $(prioritize_long_running_tests)				\
@@ -1075,9 +1037,19 @@ watch-log:
 dump-log:
 	bash -c '$(quoted_perl_command)' < LOG
 
+# Machine-parseable progress output for automated monitoring (e.g., Claude Code)
+# Outputs JSON: {"status":"running","completed":45,"total":100,"failed":0,"percent":45,"eta_seconds":120}
+check-progress:
+	@build_tools/check_progress.sh
+
 # If J != 1 and GNU parallel is installed, run the tests in parallel,
 # via the check_0 rule above.  Otherwise, run them sequentially.
 check: all
+	$(AM_V_at)echo "Cleaning up stale test directories older than 3 hours..."; \
+	  test_tmpdir_parent=$$(dirname $(TEST_TMPDIR)); \
+	  find $$test_tmpdir_parent -maxdepth 1 -name 'rocksdb.*' -type d \
+	    -mmin +180 -exec rm -rf {} + 2>/dev/null; \
+	  true
 	$(MAKE) gen_parallel_tests
 	$(AM_V_GEN)if test "$(J)" != 1                                  \
 	    && (build_tools/gnu_parallel --gnu --help 2>/dev/null) |                    \
@@ -1093,6 +1065,7 @@ ifneq ($(PLATFORM), OS_AIX)
 	$(PYTHON) tools/check_all_python.py
 ifndef ASSERT_STATUS_CHECKED # not yet working with these tests
 	$(PYTHON) tools/ldb_test.py
+	$(PYTHON) tools/db_crashtest_test.py
 	sh tools/rocksdb_dump_test.sh
 endif
 endif
@@ -1100,6 +1073,7 @@ ifndef SKIP_FORMAT_BUCK_CHECKS
 	$(MAKE) check-format
 	$(MAKE) check-buck-targets
 	$(MAKE) check-sources
+	$(MAKE) check-workflow-yaml
 endif
 
 # TODO add ldb_tests
@@ -1110,6 +1084,10 @@ check_some: $(ROCKSDBTESTS_SUBSET)
 ldb_tests: ldb
 	$(PYTHON) tools/ldb_test.py
 
+.PHONY: db_crashtest_tests
+db_crashtest_tests:
+	$(PYTHON) tools/db_crashtest_test.py
+
 include crash_test.mk
 
 asan_check: clean
@@ -1286,15 +1264,59 @@ tags0:
 format:
 	build_tools/format-diff.sh
 
+# Non-interactive format (auto-apply without prompts, for CI/automation/Claude Code)
+format-auto:
+	build_tools/format-diff.sh -y
+
 check-format:
 	build_tools/format-diff.sh -c
 
+
+# Crude alternative to setup-hooks: copies hooks into .git/hooks/ instead of
+# using core.hooksPath. The copies won't track changes to githooks/.
+install-hooks:
+	@echo "Installing git hooks from githooks/..."
+	@if [ -d githooks ]; then \
+		for hook in githooks/*; do \
+			hook_name=$$(basename "$$hook"); \
+			cp "$$hook" .git/hooks/"$$hook_name"; \
+			chmod +x .git/hooks/"$$hook_name"; \
+			echo "  Installed $$hook_name"; \
+		done; \
+		echo "Done. Hooks installed to .git/hooks/"; \
+	else \
+		echo "Error: githooks/ directory not found"; \
+		exit 1; \
+	fi
+
+# Reverse of install-hooks (not needed if using setup-hooks / core.hooksPath).
+uninstall-hooks:
+	@echo "Removing installed git hooks..."
+	@for hook in githooks/*; do \
+		hook_name=$$(basename "$$hook"); \
+		rm -f .git/hooks/"$$hook_name"; \
+		echo "  Removed $$hook_name"; \
+	done
+	@echo "Done."
+
 check-buck-targets:
 	buckifier/check_buck_targets.sh
 
 check-sources:
 	build_tools/check-sources.sh
 
+check-workflow-yaml:
+	build_tools/check-workflow-yaml.sh
+
+# Run clang-tidy on locally changed files, filtered to changed lines only.
+# Requires compile_commands.json (generate with cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON).
+# Override CLANG_TIDY_BINARY and CLANG_TIDY_JOBS as needed:
+#   make clang-tidy CLANG_TIDY_BINARY=/usr/bin/clang-tidy CLANG_TIDY_JOBS=8
+CLANG_TIDY_BINARY ?= /opt/homebrew/opt/llvm/bin/clang-tidy
+CLANG_TIDY_JOBS ?= $(shell nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)
+clang-tidy:
+	python3 tools/run_clang_tidy.py --clang-tidy-binary $(CLANG_TIDY_BINARY) -j $(CLANG_TIDY_JOBS)
+
 package:
 	bash build_tools/make_package.sh $(SHARED_MAJOR).$(SHARED_MINOR)
 
@@ -1345,6 +1367,9 @@ block_cache_trace_analyzer: $(OBJ_DIR)/tools/block_cache_analyzer/block_cache_tr
 cache_bench: $(OBJ_DIR)/cache/cache_bench.o $(CACHE_BENCH_OBJECTS) $(LIBRARY)
 	$(AM_LINK)
 
+point_lock_bench: $(OBJ_DIR)/utilities/transactions/lock/point/point_lock_bench.o $(POINT_LOCK_BENCH_OBJECTS) $(LIBRARY)
+	$(AM_LINK)
+
 persistent_cache_bench: $(OBJ_DIR)/utilities/persistent_cache/persistent_cache_bench.o $(LIBRARY)
 	$(AM_LINK)
 
@@ -1357,6 +1382,9 @@ filter_bench: $(OBJ_DIR)/util/filter_bench.o $(LIBRARY)
 db_stress: $(OBJ_DIR)/db_stress_tool/db_stress.o $(STRESS_LIBRARY) $(TOOLS_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+db_stress_compression_manager: $(OBJ_DIR)/db_stress_tool/db_stress_compression_manager.o $(LIBRARY)
+	$(AM_LINK)
+
 write_stress: $(OBJ_DIR)/tools/write_stress.o $(LIBRARY)
 	$(AM_LINK)
 
@@ -1422,13 +1450,13 @@ agg_merge_test: $(OBJ_DIR)/utilities/agg_merge/agg_merge_test.o $(TEST_LIBRARY)
 stringappend_test: $(OBJ_DIR)/utilities/merge_operators/string_append/stringappend_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
-cassandra_format_test: $(OBJ_DIR)/utilities/cassandra/cassandra_format_test.o $(OBJ_DIR)/utilities/cassandra/test_utils.o $(TEST_LIBRARY) $(LIBRARY)
+cassandra_format_test: $(OBJ_DIR)/utilities/cassandra/cassandra_format_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
-cassandra_functional_test: $(OBJ_DIR)/utilities/cassandra/cassandra_functional_test.o $(OBJ_DIR)/utilities/cassandra/test_utils.o $(TEST_LIBRARY) $(LIBRARY)
+cassandra_functional_test: $(OBJ_DIR)/utilities/cassandra/cassandra_functional_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
-cassandra_row_merge_test: $(OBJ_DIR)/utilities/cassandra/cassandra_row_merge_test.o $(OBJ_DIR)/utilities/cassandra/test_utils.o $(TEST_LIBRARY) $(LIBRARY)
+cassandra_row_merge_test: $(OBJ_DIR)/utilities/cassandra/cassandra_row_merge_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
 cassandra_serialize_test: $(OBJ_DIR)/utilities/cassandra/cassandra_serialize_test.o $(TEST_LIBRARY) $(LIBRARY)
@@ -1467,6 +1495,9 @@ db_basic_test: $(OBJ_DIR)/db/db_basic_test.o $(TEST_LIBRARY) $(LIBRARY)
 db_blob_basic_test: $(OBJ_DIR)/db/blob/db_blob_basic_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+db_blob_direct_write_test: $(OBJ_DIR)/db/blob/db_blob_direct_write_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 db_blob_compaction_test: $(OBJ_DIR)/db/blob/db_blob_compaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1476,6 +1507,9 @@ db_readonly_with_timestamp_test: $(OBJ_DIR)/db/db_readonly_with_timestamp_test.o
 db_wide_basic_test: $(OBJ_DIR)/db/wide/db_wide_basic_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+db_wide_blob_direct_write_test: $(OBJ_DIR)/db/wide/db_wide_blob_direct_write_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 db_with_timestamp_basic_test: $(OBJ_DIR)/db/db_with_timestamp_basic_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1485,12 +1519,21 @@ db_with_timestamp_compaction_test: db/db_with_timestamp_compaction_test.o $(TEST
 db_encryption_test: $(OBJ_DIR)/db/db_encryption_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+db_open_with_config_test: $(OBJ_DIR)/db/db_open_with_config_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 db_test: $(OBJ_DIR)/db/db_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
 db_test2: $(OBJ_DIR)/db/db_test2.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+db_etc3_test: $(OBJ_DIR)/db/db_etc3_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
+compression_test: $(OBJ_DIR)/util/compression_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 db_logical_block_size_cache_test: $(OBJ_DIR)/db/db_logical_block_size_cache_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1512,6 +1555,9 @@ db_compaction_filter_test: $(OBJ_DIR)/db/db_compaction_filter_test.o $(TEST_LIBR
 db_compaction_test: $(OBJ_DIR)/db/db_compaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+db_compaction_abort_test: $(OBJ_DIR)/db/db_compaction_abort_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 db_clip_test: $(OBJ_DIR)/db/db_clip_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1620,6 +1666,9 @@ backup_engine_test: $(OBJ_DIR)/utilities/backup/backup_engine_test.o $(TEST_LIBR
 checkpoint_test: $(OBJ_DIR)/utilities/checkpoint/checkpoint_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+sorted_run_builder_test: $(OBJ_DIR)/utilities/sorted_run_builder/sorted_run_builder_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 cache_simulator_test: $(OBJ_DIR)/utilities/simulator_cache/cache_simulator_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1638,6 +1687,12 @@ object_registry_test: $(OBJ_DIR)/utilities/object_registry_test.o $(TEST_LIBRARY
 ttl_test: $(OBJ_DIR)/utilities/ttl/ttl_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+trie_index_db_test: $(OBJ_DIR)/utilities/trie_index/trie_index_db_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
+trie_index_test: $(OBJ_DIR)/utilities/trie_index/trie_index_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 types_util_test: $(OBJ_DIR)/utilities/types_util_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1689,6 +1744,9 @@ io_posix_test: $(OBJ_DIR)/env/io_posix_test.o $(TEST_LIBRARY) $(LIBRARY)
 fault_injection_test: $(OBJ_DIR)/db/fault_injection_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+fault_injection_fs_test: $(OBJ_DIR)/utilities/fault_injection_fs_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 rate_limiter_test: $(OBJ_DIR)/util/rate_limiter_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1875,6 +1933,9 @@ heap_test: $(OBJ_DIR)/util/heap_test.o $(TEST_LIBRARY) $(LIBRARY)
 point_lock_manager_test: utilities/transactions/lock/point/point_lock_manager_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+point_lock_manager_stress_test: utilities/transactions/lock/point/point_lock_manager_stress_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 transaction_test: $(OBJ_DIR)/utilities/transactions/transaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1884,6 +1945,9 @@ write_committed_transaction_ts_test: $(OBJ_DIR)/utilities/transactions/write_com
 write_prepared_transaction_test: $(OBJ_DIR)/utilities/transactions/write_prepared_transaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+write_prepared_transaction_seqno_test: $(OBJ_DIR)/utilities/transactions/write_prepared_transaction_seqno_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 write_unprepared_transaction_test: $(OBJ_DIR)/utilities/transactions/write_unprepared_transaction_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -1989,6 +2053,9 @@ blob_source_test: $(OBJ_DIR)/db/blob/blob_source_test.o $(TEST_LIBRARY) $(LIBRAR
 blob_garbage_meter_test: $(OBJ_DIR)/db/blob/blob_garbage_meter_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+io_dispatcher_test: $(OBJ_DIR)/util/io_dispatcher_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 timer_test: $(OBJ_DIR)/util/timer_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
@@ -2034,6 +2101,9 @@ wide_column_serialization_test: $(OBJ_DIR)/db/wide/wide_column_serialization_tes
 wide_columns_helper_test: $(OBJ_DIR)/db/wide/wide_columns_helper_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+interval_test: $(OBJ_DIR)/util/interval_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 #-------------------------------------------------
 # make install related stuff
 PREFIX ?= /usr/local
@@ -2144,14 +2214,14 @@ ZLIB_DOWNLOAD_BASE ?= http://zlib.net
 BZIP2_VER ?= 1.0.8
 BZIP2_SHA256 ?= ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269
 BZIP2_DOWNLOAD_BASE ?= http://sourceware.org/pub/bzip2
-SNAPPY_VER ?= 1.2.1
-SNAPPY_SHA256 ?= 736aeb64d86566d2236ddffa2865ee5d7a82d26c9016b36218fcc27ea4f09f86
+SNAPPY_VER ?= 1.2.2
+SNAPPY_SHA256 ?= 90f74bc1fbf78a6c56b3c4a082a05103b3a56bb17bca1a27e052ea11723292dc
 SNAPPY_DOWNLOAD_BASE ?= https://github.com/google/snappy/archive
-LZ4_VER ?= 1.9.4
-LZ4_SHA256 ?= 0b0e3aa07c8c063ddf40b082bdf7e37a1562bda40a0ff5272957f3e987e0e54b
+LZ4_VER ?= 1.10.0
+LZ4_SHA256 ?= 537512904744b35e232912055ccf8ec66d768639ff3abe5788d90d792ec5f48b
 LZ4_DOWNLOAD_BASE ?= https://github.com/lz4/lz4/archive
-ZSTD_VER ?= 1.5.5
-ZSTD_SHA256 ?= 98e9c3d949d1b924e28e01eccb7deed865eefebf25c2f21c702e5cd5b63b85e1
+ZSTD_VER ?= 1.5.7
+ZSTD_SHA256 ?= 37d7284556b20954e56e1ca85b80226768902e2edabd3b649e9e72c0c9012ee3
 ZSTD_DOWNLOAD_BASE ?= https://github.com/facebook/zstd/archive
 CURL_SSL_OPTS ?= --tlsv1
 
@@ -2242,7 +2312,7 @@ libsnappy.a: snappy-$(SNAPPY_VER).tar.gz
 	-rm -rf snappy-$(SNAPPY_VER)
 	tar xvzf snappy-$(SNAPPY_VER).tar.gz
 	mkdir snappy-$(SNAPPY_VER)/build
-	cd snappy-$(SNAPPY_VER)/build && CFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' CXXFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CXXFLAGS} ${EXTRA_CXXFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DSNAPPY_BUILD_BENCHMARKS=OFF -DSNAPPY_BUILD_TESTS=OFF --compile-no-warning-as-error ${PLATFORM_CMAKE_FLAGS} .. && $(MAKE) ${SNAPPY_MAKE_TARGET}
+	cd snappy-$(SNAPPY_VER)/build && CFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' CXXFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CXXFLAGS} ${EXTRA_CXXFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DSNAPPY_BUILD_BENCHMARKS=OFF -DSNAPPY_BUILD_TESTS=OFF ${PLATFORM_CMAKE_FLAGS} .. && $(MAKE) ${SNAPPY_MAKE_TARGET}
 	cp snappy-$(SNAPPY_VER)/build/libsnappy.a .
 
 lz4-$(LZ4_VER).tar.gz:
@@ -2372,27 +2442,27 @@ rocksdbjavastaticreleasedocker: rocksdbjavastaticosx rocksdbjavastaticdockerx86
 
 rocksdbjavastaticdockerx86:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_x86-be --platform linux/386 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos6_x86-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_x86-be --platform linux/386 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos7_x86-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerx86_64:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_x64-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos6_x64-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_x64-be --platform linux/amd64 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos7_x64-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerppc64le:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_ppc64le-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos7_ppc64le-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_ppc64le-be --platform linux/ppc64le --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos7_ppc64le-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerarm64v8:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_arm64v8-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos7_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_arm64v8-be --platform linux/aarch64 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:centos7_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockers390x:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_s390x-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:ubuntu18_s390x-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_s390x-be --platform linux/s390x --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:ubuntu18_s390x-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerriscv64:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_riscv64-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:ubuntu20_riscv64-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_riscv64-be --platform linux/riscv64 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:ubuntu20_riscv64-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerx86musl:
 	mkdir -p java/target
@@ -2400,19 +2470,19 @@ rocksdbjavastaticdockerx86musl:
 
 rocksdbjavastaticdockerx86_64musl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_x64-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_x64-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_x64-musl-be --platform linux/amd64 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_x64-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerppc64lemusl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_ppc64le-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_ppc64le-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_ppc64le-musl-be --platform linux/ppc64le --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_ppc64le-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockerarm64v8musl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_arm64v8-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_arm64v8-musl-be --platform linux/aarch64 --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_arm64v8-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticdockers390xmusl:
 	mkdir -p java/target
-	docker run --rm --name rocksdb_linux_s390x-musl-be --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_s390x-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
+	docker run --rm --name rocksdb_linux_s390x-musl-be --platform linux/s390x --attach stdin --attach stdout --attach stderr --volume $(HOME)/.m2:/root/.m2:ro --volume `pwd`:/rocksdb-host:ro --volume /rocksdb-local-build --volume `pwd`/java/target:/rocksdb-java-target --env DEBUG_LEVEL=$(DEBUG_LEVEL) --env J=$(J) evolvedbinary/rocksjava:alpine3_s390x-be /rocksdb-host/java/crossbuild/docker-build-linux.sh
 
 rocksdbjavastaticpublish: rocksdbjavastaticrelease rocksdbjavastaticpublishcentral
 
@@ -2467,8 +2537,8 @@ jtest_run:
 jtest: rocksdbjava
 	cd java;$(MAKE) sample test
 
-jpmd: rocksdbjava rocksdbjavageneratepom
-	cd java;$(MAKE) pmd
+jpmd: rocksdbjavageneratepom
+	cd java;$(MAKE) java java_test pmd
 
 jdb_bench:
 	cd java;$(MAKE) db_bench;
@@ -2478,38 +2548,6 @@ commit_prereq:
 	false # J=$(J) build_tools/precommit_checker.py unit clang_unit release clang_release tsan asan ubsan lite unit_non_shm
 	# $(MAKE) clean && $(MAKE) jclean && $(MAKE) rocksdbjava;
 
-# For public CI runs, checkout folly in a way that can build with RocksDB.
-# This is mostly intended as a test-only simulation of Meta-internal folly
-# integration.
-checkout_folly:
-	if [ -e third-party/folly ]; then \
-		cd third-party/folly && ${GIT_COMMAND} fetch origin; \
-	else \
-		cd third-party && ${GIT_COMMAND} clone https://github.com/facebook/folly.git; \
-	fi
-	@# Pin to a particular version for public CI, so that PR authors don't
-	@# need to worry about folly breaking our integration. Update periodically
-	cd third-party/folly && git reset --hard 78286282478e1ae05b2e8cbcf0e2139eab283bea
-	@# NOTE: this hack is required for clang in some cases
-	perl -pi -e 's/int rv = syscall/int rv = (int)syscall/' third-party/folly/folly/detail/Futex.cpp
-	@# NOTE: this hack is required for gcc in some cases
-	perl -pi -e 's/(__has_include.<experimental.memory_resource>.)/__cpp_rtti && $$1/' third-party/folly/folly/memory/MemoryResource.h
-	@# NOTE: boost source will be needed for any build including `USE_FOLLY_LITE` builds as those depend on boost headers
-	cd third-party/folly && $(PYTHON) build/fbcode_builder/getdeps.py fetch boost
-
-CXX_M_FLAGS = $(filter -m%, $(CXXFLAGS))
-
-build_folly:
-	FOLLY_INST_PATH=`cd third-party/folly; $(PYTHON) build/fbcode_builder/getdeps.py show-inst-dir`; \
-	if [ "$$FOLLY_INST_PATH" ]; then \
-		rm -rf $${FOLLY_INST_PATH}/../../*; \
-	else \
-		echo "Please run checkout_folly first"; \
-		false; \
-	fi
-	cd third-party/folly && \
-		CXXFLAGS=" $(CXX_M_FLAGS) -DHAVE_CXX11_ATOMIC " $(PYTHON) build/fbcode_builder/getdeps.py build --no-tests
-
 # ---------------------------------------------------------------------------
 #   Build size testing
 # ---------------------------------------------------------------------------
@@ -2630,7 +2668,7 @@ list_all_tests:
 
 # 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 check-headers check-sources jclean jtest package analyze tags rocksdbjavastatic% unity.% unity_test checkout_folly, $(MAKECMDGOALS))
+ROCKS_DEP_RULES=$(filter-out clean format check-format check-buck-targets check-headers check-sources check-workflow-yaml clang-tidy jclean jtest package analyze tags rocksdbjavastatic% unity.% unity_test checkout_folly, $(MAKECMDGOALS))
 ifneq ("$(ROCKS_DEP_RULES)", "")
 -include $(DEPFILES)
 endif

buckifier/buckify_rocksdb.py

@@ -135,6 +135,9 @@ def generate_buck(repo_path, deps_map):
 
     BUCK = TARGETSBuilder("%s/BUCK" % repo_path, extra_argv)
 
+    # Add oncall("rocksdb_point_of_contact") at the top
+    BUCK.add_oncall("rocksdb_point_of_contact")
+
     # rocksdb_lib
     BUCK.add_library(
         "rocksdb_lib",
@@ -143,10 +146,10 @@ def generate_buck(repo_path, deps_map):
         src_mk["RANGE_TREE_SOURCES"] + src_mk["TOOL_LIB_SOURCES"],
         deps=[
             "//folly/container:f14_hash",
-            "//folly/experimental/coro:blocking_wait",
-            "//folly/experimental/coro:collect",
-            "//folly/experimental/coro:coroutine",
-            "//folly/experimental/coro:task",
+            "//folly/coro:blocking_wait",
+            "//folly/coro:collect",
+            "//folly/coro:coroutine",
+            "//folly/coro:task",
             "//folly/synchronization:distributed_mutex",
         ],
         headers=LiteralValue("glob([\"**/*.h\"])")
@@ -206,6 +209,12 @@ def generate_buck(repo_path, deps_map):
         src_mk.get("CACHE_BENCH_LIB_SOURCES", []),
         [":rocksdb_lib"],
     )
+    # rocksdb_point_lock_bench_tools_lib
+    BUCK.add_library(
+        "rocksdb_point_lock_bench_tools_lib",
+        src_mk.get("POINT_LOCK_BENCH_LIB_SOURCES", []),
+        [":rocksdb_lib"],
+    )
     # rocksdb_stress_lib
     BUCK.add_rocksdb_library(
         "rocksdb_stress_lib",
@@ -229,6 +238,12 @@ def generate_buck(repo_path, deps_map):
     BUCK.add_binary(
         "cache_bench", ["cache/cache_bench.cc"], [":rocksdb_cache_bench_tools_lib"]
     )
+    # point_lock_bench binary
+    BUCK.add_binary(
+        "point_lock_bench",
+        ["utilities/transactions/lock/point/point_lock_bench.cc"],
+        [":rocksdb_point_lock_bench_tools_lib"]
+    )
     # bench binaries
     for src in src_mk.get("MICROBENCH_SOURCES", []):
         name = src.rsplit("/", 1)[1].split(".")[0] if "/" in src else src.split(".")[0]

buckifier/targets_builder.py

@@ -45,6 +45,11 @@ class TARGETSBuilder:
         self.total_bin = 0
         self.total_test = 0
         self.tests_cfg = ""
+    
+    def add_oncall(self, oncall):
+       with open(self.path, "ab") as targets_file:
+            targets_file.write(targets_cfg.oncall_template.format(name=oncall).encode("utf-8"))
+                
 
     def add_library(
         self,

buckifier/targets_cfg.py

@@ -1,10 +1,12 @@
-# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+#  Copyright (c) Meta Platforms, Inc. and affiliates.
+#  This source code is licensed under both the GPLv2 (found in the COPYING file in the root directory)
+#  and the Apache 2.0 License (found in the LICENSE.Apache file in the root directory).
 
 rocksdb_target_header_template = """# This file \100generated by:
 #$ python3 buckifier/buckify_rocksdb.py{extra_argv}
 # --> DO NOT EDIT MANUALLY <--
-# This file is a Facebook-specific integration for buck builds, so can
-# only be validated by Facebook employees.
+# This file is a Meta-specific integration for buck builds, so can
+# only be validated by Meta employees.
 load("//rocks/buckifier:defs.bzl", "cpp_library_wrapper","rocks_cpp_library_wrapper","cpp_binary_wrapper","cpp_unittest_wrapper","fancy_bench_wrapper","add_c_test_wrapper")
 load("@fbcode_macros//build_defs:export_files.bzl", "export_file")
 
@@ -41,3 +43,8 @@ fancy_bench_wrapper(suite_name="{name}", binary_to_bench_to_metric_list_map={ben
 export_file_template = """
 export_file(name = "{name}")
 """
+
+
+oncall_template = """
+oncall("{name}")
+"""

build_tools/build_detect_platform

@@ -45,18 +45,21 @@ if test -z "$OUTPUT"; then
   exit 1
 fi
 
-# we depend on C++17, but should be compatible with newer standards
+# we depend on C++20, but should be compatible with newer standards
 if [ "$ROCKSDB_CXX_STANDARD" ]; then
   PLATFORM_CXXFLAGS="-std=$ROCKSDB_CXX_STANDARD"
 else
-  PLATFORM_CXXFLAGS="-std=c++17"
+  PLATFORM_CXXFLAGS="-std=c++20"
 fi
 
 # we currently depend on POSIX platform
 COMMON_FLAGS="-DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX"
 
-# Default to fbcode gcc on internal fb machines
-if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
+# Default to fbcode gcc on Meta internal machines
+IS_META_HOST="$(hostname | grep -E '(facebook|meta).com|fbinfra.net')"
+if [ -z "$ROCKSDB_NO_FBCODE" -a "$IS_META_HOST" ]; then
+  if [ -d /mnt/gvfs/third-party ]; then
+    echo "NOTE: Using fbcode build" >&2
     FBCODE_BUILD="true"
     # If we're compiling with TSAN or shared lib, we need pic build
     PIC_BUILD=$COMPILE_WITH_TSAN
@@ -64,6 +67,11 @@ if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
       PIC_BUILD=1
     fi
     source "$PWD/build_tools/fbcode_config_platform010.sh"
+  else
+    echo "************************************************************************" >&2
+    echo "WARNING: -d /mnt/gvfs/third-party failed; no fbcode build" >&2
+    echo "************************************************************************" >&2
+  fi
 fi
 
 # Delete existing output, if it exists
@@ -71,7 +79,9 @@ rm -f "$OUTPUT"
 touch "$OUTPUT"
 
 if test -z "$CC"; then
-    if [ -x "$(command -v cc)" ]; then
+    if [ "$USE_CLANG" -a -x "$(command -v clang)" ]; then
+        CC=clang
+    elif [ -x "$(command -v cc)" ]; then
         CC=cc
     elif [ -x "$(command -v clang)" ]; then
         CC=clang
@@ -81,7 +91,9 @@ if test -z "$CC"; then
 fi
 
 if test -z "$CXX"; then
-    if [ -x "$(command -v g++)" ]; then
+    if [ "$USE_CLANG" -a -x "$(command -v clang++)" ]; then
+        CXX=clang++
+    elif [ -x "$(command -v g++)" ]; then
         CXX=g++
     elif [ -x "$(command -v clang++)" ]; then
         CXX=clang++
@@ -91,7 +103,9 @@ if test -z "$CXX"; then
 fi
 
 if test -z "$AR"; then
-    if [ -x "$(command -v gcc-ar)" ]; then
+    if [ "$USE_CLANG" -a -x "$(command -v llvm-ar)" ]; then
+        AR=llvm-ar
+    elif [ -x "$(command -v gcc-ar)" ]; then
         AR=gcc-ar
     elif [ -x "$(command -v llvm-ar)" ]; then
         AR=llvm-ar
@@ -134,6 +148,24 @@ PLATFORM_SHARED_LDFLAGS="-Wl,--no-as-needed -shared -Wl,-soname -Wl,"
 PLATFORM_SHARED_CFLAGS="-fPIC"
 PLATFORM_SHARED_VERSIONED=true
 
+# Prefer lld linker when available on Linux. lld is typically 5-10x faster
+# than the default ld.bfd for large C++ projects. macOS uses ld64 (or
+# ld-prime) which is already fast, so we skip lld detection there.
+# Set ROCKSDB_NO_FAST_LINKER=1 to disable this auto-detection.
+if [ -z "$ROCKSDB_NO_FAST_LINKER" ] && [ "$TARGET_OS" = "Linux" ]; then
+    if $CXX -fuse-ld=lld -L/usr/local/lib -x c++ - -o /dev/null 2>/dev/null <<EOF
+int main() { return 0; }
+EOF
+    then
+        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -fuse-ld=lld"
+        # Ensure lld can find libraries in /usr/local/lib (lld does not
+        # search there by default, unlike ld.bfd)
+        if [ -d /usr/local/lib ]; then
+            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -L/usr/local/lib"
+        fi
+    fi
+fi
+
 # generic port files (working on all platform by #ifdef) go directly in /port
 GENERIC_PORT_FILES=`cd "$ROCKSDB_ROOT"; find port -name '*.cc' | tr "\n" " "`
 
@@ -297,7 +329,8 @@ EOF
 EOF
         then
           COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=1"
-          PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
+          # Hack: don't link extra gflags assuming it comes with folly
+          [ "$USE_FOLLY" ] || PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
         # check if namespace is gflags
         elif $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null << EOF
             #include <gflags/gflags.h>
@@ -306,7 +339,8 @@ EOF
 EOF
         then
           COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=1 -DGFLAGS_NAMESPACE=gflags"
-          PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
+          # Hack: don't link extra gflags assuming it comes with folly
+          [ "$USE_FOLLY" ] || PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
         # check if namespace is google
         elif $CXX $PLATFORM_CXXFLAGS -x c++ - -o test.o 2>/dev/null << EOF
             #include <gflags/gflags.h>
@@ -758,6 +792,7 @@ fi
 if [ "$USE_FOLLY_LITE" ]; then
   if [ "$FOLLY_DIR" ]; then
     BOOST_SOURCE_PATH=`cd $FOLLY_DIR && $PYTHON build/fbcode_builder/getdeps.py show-source-dir boost`
+    FMT_SOURCE_PATH=`cd $FOLLY_DIR && $PYTHON build/fbcode_builder/getdeps.py show-source-dir fmt`
   fi
 fi
 
@@ -802,6 +837,7 @@ echo "FIND=$FIND" >> "$OUTPUT"
 echo "WATCH=$WATCH" >> "$OUTPUT"
 echo "FOLLY_PATH=$FOLLY_PATH" >> "$OUTPUT"
 echo "BOOST_SOURCE_PATH=$BOOST_SOURCE_PATH" >> "$OUTPUT"
+echo "FMT_SOURCE_PATH=$FMT_SOURCE_PATH" >> "$OUTPUT"
 
 # This will enable some related identifiers for the preprocessor
 if test -n "$JEMALLOC"; then
@@ -813,7 +849,6 @@ fi
 if test -n "$WITH_JEMALLOC_FLAG"; then
   echo "WITH_JEMALLOC_FLAG=$WITH_JEMALLOC_FLAG" >> "$OUTPUT"
 fi
-echo "LUA_PATH=$LUA_PATH" >> "$OUTPUT"
 if test -n "$USE_FOLLY"; then
   echo "USE_FOLLY=$USE_FOLLY" >> "$OUTPUT"
 fi

build_tools/check-public-header.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Copyright (c) Meta Platforms, Inc. and affiliates. All Rights Reserved.
+#
+# Check for some simple mistakes in public headers (on the command line)
+# that should prevent commit or push
+
+BAD=""
+
+# Look for potential for ODR violations caused by public headers depending on
+# build parameters that could vary between RocksDB build and application build.
+# * Cases like ROCKSDB_NAMESPACE, and ROCKSDB_ASSERT_STATUS_CHECKED are
+#   intentional, hard to avoid. (We expect definitions to change and the user
+#   should also.)
+# * Cases like _WIN32, OS_WIN, and __cplusplus are essentially ODR-safe.
+# * Cases like
+#   #ifdef BLAH  // ODR-SAFE
+#   #undef BLAH
+#   #endif
+#   that should not cause ODR violations can be exempted with the ODR-SAFE
+#   marker recognized here.
+
+grep -nHE '^#if' -- "$@" | grep -vE 'ROCKSDB_NAMESPACE|ROCKSDB_ASSERT_STATUS_CHECKED|_WIN32|OS_WIN|ODR-SAFE|__cplusplus|ROCKSDB_DLL|ROCKSDB_LIBRARY_EXPORTS'
+if [ "$?" != "1" ]; then
+  echo "^^^^^ #if in public API could cause an ODR violation."
+  echo "      Add // ODR-SAFE if verified safe."
+  BAD=1
+fi
+
+if [ "$BAD" ]; then
+  exit 1
+fi

build_tools/check-sources.sh

@@ -37,7 +37,7 @@ if [ "$?" != "1" ]; then
   BAD=1
 fi
 
-git grep -n -P "[\x80-\xFF]" -- ':!docs' ':!*.md'
+LC_ALL=C git grep -n $'[\x80-\xff]' -- ':!docs' ':!*.md' ':!.github'
 if [ "$?" != "1" ]; then
   echo '^^^^ Use only ASCII characters in source files'
   BAD=1

build_tools/check-workflow-yaml.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+#
+# Validate GitHub Actions workflow YAML before it reaches CI runtime.
+
+set -euo pipefail
+
+if ! command -v ruby >/dev/null 2>&1; then
+  echo "ruby is required to validate GitHub Actions workflow YAML"
+  echo "On CentOS Stream: sudo dnf install ruby rubygems rubygem-psych"
+  exit 1
+fi
+
+if ! ruby -e 'require "psych"' 2>/dev/null; then
+  echo "ruby is installed but cannot load required library 'psych'"
+  echo "On CentOS Stream: sudo dnf install rubygems rubygem-psych"
+  exit 1
+fi
+
+ruby <<'RUBY'
+require "psych"
+
+bad = false
+workflow_files = Dir[".github/workflows/*.{yml,yaml}"].sort
+
+if workflow_files.empty?
+  warn "No workflow YAML files found under .github/workflows"
+  exit 1
+end
+
+workflow_files.each do |path|
+  begin
+    Psych.parse_file(path)
+    puts "OK #{path}"
+  rescue Psych::Exception => e
+    warn "Invalid YAML in #{path}: #{e.message}"
+    bad = true
+  end
+end
+
+exit(bad ? 1 : 0)
+RUBY

build_tools/check_progress.sh

@@ -0,0 +1,231 @@
+#!/bin/bash
+# Output test progress in JSON format for machine parsing
+# Usage: build_tools/check_progress.sh
+
+LOG_FILE="LOG"
+T_DIR="t"
+SRC_MK="src.mk"
+
+# Maximum lines of test output to include per failed test
+MAX_OUTPUT_LINES=50
+
+# Helper to escape string for JSON (handles newlines, quotes, backslashes, tabs)
+json_escape() {
+    local str="$1"
+    # Use python for reliable JSON escaping if available, otherwise use sed
+    if command -v python3 &>/dev/null; then
+        printf '%s' "$str" | python3 -c 'import json,sys; print(json.dumps(sys.stdin.read())[1:-1], end="")'
+    else
+        printf '%s' "$str" | sed 's/\\/\\\\/g; s/"/\\"/g; s/\t/\\t/g; s/\r/\\r/g' | awk '{printf "%s\\n", $0}' | sed 's/\\n$//'
+    fi
+}
+
+# Helper to output JSON and exit
+output_json() {
+    local status="$1"
+    local completed="${2:-0}"
+    local total="${3:-0}"
+    local failed="${4:-0}"
+    local percent="${5:-0}"
+    local eta="${6:-0}"
+    local avg_time="${7:-0}"
+    local last_item="${8:-}"
+    local phase="${9:-}"
+    local failed_tests="${10:-}"
+
+    # Build JSON output
+    local json="{\"status\":\"$status\""
+
+    if [[ -n "$phase" ]]; then
+        json="$json,\"phase\":\"$phase\""
+    fi
+
+    json="$json,\"completed\":$completed,\"total\":$total,\"failed\":$failed,\"percent\":$percent"
+    json="$json,\"eta_seconds\":$eta,\"avg_time\":\"$avg_time\",\"last_item\":\"$(json_escape "$last_item")\""
+
+    if [[ -n "$failed_tests" ]]; then
+        json="$json,\"failed_tests\":[$failed_tests]"
+    fi
+
+    json="$json}"
+    echo "$json"
+}
+
+# Get failed test info with log output
+get_failed_tests_json() {
+    local log_file="$1"
+    local t_dir="$2"
+    local max_failures=10
+    local count=0
+    local first=true
+
+    # Get failed tests from LOG file
+    while IFS=$'\t' read -r seq host starttime runtime send recv exitval signal cmd; do
+        # Skip header line
+        [[ "$seq" == "Seq" ]] && continue
+
+        # Check if failed (exitval != 0 or signal != 0)
+        if [[ "$exitval" != "0" || "$signal" != "0" ]]; then
+            # Extract test name from command
+            test_name=$(echo "$cmd" | sed 's,.*/run-,,;s, .*,,')
+
+            # Get log file path
+            log_path="$t_dir/log-run-$test_name"
+
+            # Read test output (last N lines)
+            if [[ -f "$log_path" ]]; then
+                output=$(tail -n "$MAX_OUTPUT_LINES" "$log_path" 2>/dev/null)
+            else
+                output="(log file not found: $log_path)"
+            fi
+
+            # Escape output for JSON
+            escaped_output=$(json_escape "$output")
+
+            # Build JSON object for this failure
+            if [[ "$first" == "true" ]]; then
+                first=false
+            else
+                printf ","
+            fi
+            printf '{"test":"%s","exit_code":%d,"signal":%d,"output":"%s"}' \
+                "$test_name" "$exitval" "$signal" "$escaped_output"
+
+            ((count++))
+            if [[ $count -ge $max_failures ]]; then
+                break
+            fi
+        fi
+    done < "$log_file"
+}
+
+# Check if tests are running (LOG file exists)
+if [[ -f "$LOG_FILE" ]]; then
+    # Count total tests from t/run-* files
+    if [[ -d "$T_DIR" ]]; then
+        total=$(find "$T_DIR" -name 'run-*' -type f 2>/dev/null | wc -l)
+    else
+        total=0
+    fi
+
+    # If no parallel tests generated yet
+    if [[ "$total" -eq 0 ]]; then
+        output_json "running" 0 0 0 0 0 "0" "" "generating"
+        exit 0
+    fi
+
+    # Parse LOG file (skip header line)
+    # LOG format: Seq Host Starttime JobRuntime Send Receive Exitval Signal Command
+    completed=$(tail -n +2 "$LOG_FILE" 2>/dev/null | wc -l)
+
+    # Count failures
+    failed=$(awk -F'\t' 'NR>1 && ($7 != 0 || $8 != 0) {count++} END {print count+0}' "$LOG_FILE" 2>/dev/null)
+
+    # Get failed tests JSON with output (only if there are failures)
+    if [[ "$failed" -gt 0 ]]; then
+        failed_tests=$(get_failed_tests_json "$LOG_FILE" "$T_DIR")
+    else
+        failed_tests=""
+    fi
+
+    # Calculate percentage
+    if [[ "$total" -gt 0 ]]; then
+        percent=$((completed * 100 / total))
+    else
+        percent=0
+    fi
+
+    # Get last completed test name (extract from command column)
+    last_test=$(tail -1 "$LOG_FILE" 2>/dev/null | awk -F'\t' '{print $9}' | sed 's,.*/run-,,;s, .*,,;s,^./,,')
+
+    # Calculate ETA based on average time
+    if [[ "$completed" -gt 0 ]]; then
+        avg_time=$(awk -F'\t' 'NR>1 {sum+=$4; count++} END {if(count>0) printf "%.1f", sum/count; else print "0"}' "$LOG_FILE")
+        remaining=$((total - completed))
+        eta=$(awk "BEGIN {printf \"%.0f\", $avg_time * $remaining}")
+    else
+        avg_time="0"
+        eta="0"
+    fi
+
+    # Determine status
+    if [[ "$completed" -ge "$total" ]]; then
+        status="completed"
+    elif [[ "$completed" -gt 0 ]]; then
+        status="running"
+    else
+        status="starting"
+    fi
+
+    output_json "$status" "$completed" "$total" "$failed" "$percent" "$eta" "$avg_time" "$last_test" "testing" "$failed_tests"
+    exit 0
+fi
+
+# No LOG file - check if we're in compilation/linking phase
+# Count expected source files from src.mk
+if [[ -f "$SRC_MK" ]]; then
+    # Count LIB_SOURCES (library object files to compile)
+    expected_lib_objects=$(grep -E '\.cc\s*\\?$' "$SRC_MK" | grep -v '^#' | wc -l)
+
+    # Count TEST_MAIN_SOURCES (test binaries to link)
+    expected_test_binaries=$(sed -n '/^TEST_MAIN_SOURCES =/,/^[^ ]/p' "$SRC_MK" | grep -cE '\.cc\s*\\?$' 2>/dev/null || echo 0)
+else
+    expected_lib_objects=0
+    expected_test_binaries=0
+fi
+
+# Check for test generation phase (t/ directory being created)
+if [[ -d "$T_DIR" ]]; then
+    total=$(find "$T_DIR" -name 'run-*' -type f 2>/dev/null | wc -l)
+    if [[ "$total" -gt 0 ]]; then
+        output_json "running" 0 "$total" 0 0 0 "0" "" "generating"
+        exit 0
+    fi
+fi
+
+# Count compiled object files (in subdirectories matching source structure)
+# Object files are created as dir/file.o (e.g., cache/cache.o, db/db_impl.o)
+compiled_objects=0
+if [[ "$expected_lib_objects" -gt 0 ]]; then
+    # Count .o files in source directories
+    compiled_objects=$(find cache db env file logging memory memtable monitoring options port table test_util trace_replay util utilities -name '*.o' -type f 2>/dev/null | wc -l)
+fi
+
+# Count linked test binaries (test binaries are in current directory with _test suffix)
+linked_tests=0
+if [[ "$expected_test_binaries" -gt 0 ]]; then
+    linked_tests=$(find . -maxdepth 1 -name '*_test' -type f -executable 2>/dev/null | wc -l)
+fi
+
+# Determine phase based on what exists
+if [[ "$compiled_objects" -eq 0 && "$linked_tests" -eq 0 ]]; then
+    # Nothing compiled yet - not started or just beginning
+    output_json "not_started" 0 0 0 0 0 "0" ""
+    exit 0
+fi
+
+# Calculate total work units: compiling + linking
+total_work=$((expected_lib_objects + expected_test_binaries))
+completed_work=$((compiled_objects + linked_tests))
+
+if [[ "$total_work" -gt 0 ]]; then
+    percent=$((completed_work * 100 / total_work))
+else
+    percent=0
+fi
+
+# Determine phase
+if [[ "$compiled_objects" -lt "$expected_lib_objects" ]]; then
+    phase="compiling"
+    # Get most recently modified .o file as last_item
+    last_item=$(find cache db env file logging memory memtable monitoring options port table test_util trace_replay util utilities -name '*.o' -type f -printf '%T@ %p\n' 2>/dev/null | sort -rn | head -1 | cut -d' ' -f2- | sed 's,^\./,,;s,\.o$,,')
+elif [[ "$linked_tests" -lt "$expected_test_binaries" ]]; then
+    phase="linking"
+    # Get most recently modified test binary as last_item
+    last_item=$(find . -maxdepth 1 -name '*_test' -type f -executable -printf '%T@ %p\n' 2>/dev/null | sort -rn | head -1 | cut -d' ' -f2- | sed 's,^\./,,')
+else
+    phase="generating"
+    last_item=""
+fi
+
+output_json "running" "$completed_work" "$total_work" 0 "$percent" 0 "0" "$last_item" "$phase"

build_tools/dependencies_platform010.sh

@@ -19,4 +19,3 @@ BENCHMARK_BASE=/mnt/gvfs/third-party2/benchmark/780c7a0f9cf0967961e69ad08e61cddd
 KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/624a2f8f6c93c3c1df8aa4a6255d8202631a6c80/fb/platform010/da39a3e
 BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/39579e8603b48b3540f8b0633f43adf29acccb8b/2.37/centos8-native/da39a3e
 VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/cd9cc656d49ecb53797ce4d055e49fde29fd57ff/3.19.0/platform010/76ebdda
-LUA_BASE=/mnt/gvfs/third-party2/lua/363787fa5cac2a8aa20638909210443278fa138e/5.3.4/platform010/9079c97

build_tools/fbcode_config.sh

@@ -164,12 +164,4 @@ EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GF
 
 VALGRIND_VER="$VALGRIND_BASE/bin/"
 
-LUA_PATH="$LUA_BASE"
-
-if test -z $PIC_BUILD; then
-  LUA_LIB=" $LUA_PATH/lib/liblua.a"
-else
-  LUA_LIB=" $LUA_PATH/lib/liblua_pic.a"
-fi
-
-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 CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE CLANG_ANALYZER CLANG_SCAN_BUILD

build_tools/fbcode_config_platform010.sh

@@ -172,4 +172,4 @@ EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GF
 
 VALGRIND_VER="$VALGRIND_BASE/bin/"
 
-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
+export CC CXX AR AS CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE CLANG_ANALYZER CLANG_SCAN_BUILD

build_tools/format-diff.sh

@@ -7,14 +7,18 @@ print_usage () {
   echo "Usage:"
   echo "format-diff.sh [OPTIONS]"
   echo "-c: check only."
+  echo "-y: auto-apply formatting without prompts (non-interactive mode)."
   echo "-h: print this message."
 }
 
-while getopts ':ch' OPTION; do
+while getopts ':cyh' OPTION; do
   case "$OPTION" in
     c)
       CHECK_ONLY=1
       ;;
+    y)
+      AUTO_APPLY=1
+      ;;
     h)
       print_usage
       exit 1
@@ -118,6 +122,9 @@ fi
 # fi
 set -e
 
+# Exclude third-party from formatting
+EXCLUDE=':!third-party/'
+
 uncommitted_code=`git diff HEAD`
 
 # If there's no uncommitted changes, we assume user are doing post-commit
@@ -137,14 +144,78 @@ then
   # should be relevant for formatting fixes.
   FORMAT_UPSTREAM_MERGE_BASE="$(git merge-base "$FORMAT_UPSTREAM" HEAD)"
   # Get the differences
-  diffs=$(git diff -U0 "$FORMAT_UPSTREAM_MERGE_BASE" | $CLANG_FORMAT_DIFF -p 1) || true
+  diffs=$(git diff -U0 "$FORMAT_UPSTREAM_MERGE_BASE" -- $EXCLUDE | $CLANG_FORMAT_DIFF -p 1) || true
   echo "Checking format of changes not yet in $FORMAT_UPSTREAM..."
 else
   # Check the format of uncommitted lines,
-  diffs=$(git diff -U0 HEAD | $CLANG_FORMAT_DIFF -p 1) || true
+  diffs=$(git diff -U0 HEAD -- $EXCLUDE | $CLANG_FORMAT_DIFF -p 1) || true
   echo "Checking format of uncommitted changes..."
 fi
 
+# Check for missing copyright in new files
+echo "Checking for copyright headers in new files..."
+
+# Get list of new files (added, not just modified)
+if [ -z "$uncommitted_code" ]; then
+  # Post-commit: check files added since merge base
+  new_files=$(git diff --name-only --diff-filter=A "$FORMAT_UPSTREAM_MERGE_BASE" -- '*.h' '*.cc' '*.py' $EXCLUDE)
+else
+  # Pre-commit: check staged new files
+  new_files=$(git diff --name-only --diff-filter=A --cached HEAD -- '*.h' '*.cc' '*.py' $EXCLUDE)
+fi
+
+if [ -n "$new_files" ]; then
+  files_missing_copyright=""
+
+  for file in $new_files; do
+    if [ -f "$file" ]; then
+      # Check if file is missing copyright
+      # For .py files, check for Python-style comment
+      # For .h and .cc files, check for C++-style comment
+      if [[ "$file" == *.py ]]; then
+        if ! grep -q "Copyright (c) Meta Platforms, Inc. and affiliates" "$file"; then
+          files_missing_copyright="$files_missing_copyright $file"
+          # Add copyright header to Python file
+          temp_file=$(mktemp)
+          {
+            echo "#  Copyright (c) Meta Platforms, Inc. and affiliates."
+            echo "#  This source code is licensed under both the GPLv2 (found in the COPYING file in the root directory)"
+            echo "#  and the Apache 2.0 License (found in the LICENSE.Apache file in the root directory)."
+            echo
+            cat "$file"
+          } > "$temp_file"
+          mv "$temp_file" "$file"
+          echo "Added copyright header to $file"
+        fi
+      elif [[ "$file" == *.h ]] || [[ "$file" == *.cc ]]; then
+        if ! grep -q "Copyright (c) Meta Platforms, Inc. and affiliates" "$file"; then
+          files_missing_copyright="$files_missing_copyright $file"
+          # Add copyright header to C++ file
+          temp_file=$(mktemp)
+          {
+            echo "//  Copyright (c) Meta Platforms, Inc. and affiliates. "
+            echo "//  This source code is licensed under both the GPLv2 (found in the "
+            echo "//  COPYING file in the root directory) and Apache 2.0 License "
+            echo "//  (found in the LICENSE.Apache file in the root directory)."
+            echo
+            cat "$file"
+          } > "$temp_file"
+          mv "$temp_file" "$file"
+          echo "Added copyright header to $file"
+        fi
+      fi
+    fi
+  done
+
+  if [ -n "$files_missing_copyright" ]; then
+    echo "Copyright headers were added to new files."
+  else
+    echo "All new files have copyright headers."
+  fi
+else
+  echo "No new files to check for copyright headers."
+fi
+
 if [ -z "$diffs" ]
 then
   echo "Nothing needs to be reformatted!"
@@ -173,11 +244,16 @@ echo "$diffs" |
   sed -e "s/\(^-.*$\)/`echo -e \"$COLOR_RED\1$COLOR_END\"`/" |
   sed -e "s/\(^+.*$\)/`echo -e \"$COLOR_GREEN\1$COLOR_END\"`/"
 
-echo -e "Would you like to fix the format automatically (y/n): \c"
+# Handle auto-apply mode (non-interactive)
+if [ "$AUTO_APPLY" ]; then
+  to_fix="y"
+else
+  echo -e "Would you like to fix the format automatically (y/n): \c"
 
-# Make sure under any mode, we can read user input.
-exec < /dev/tty
-read to_fix
+  # Make sure under any mode, we can read user input.
+  exec < /dev/tty
+  read to_fix
+fi
 
 if [ "$to_fix" != "y" ]
 then
@@ -187,14 +263,15 @@ fi
 # Do in-place format adjustment.
 if [ -z "$uncommitted_code" ]
 then
-  git diff -U0 "$FORMAT_UPSTREAM_MERGE_BASE" | $CLANG_FORMAT_DIFF -i -p 1
+  git diff -U0 "$FORMAT_UPSTREAM_MERGE_BASE" -- $EXCLUDE | $CLANG_FORMAT_DIFF -i -p 1
 else
-  git diff -U0 HEAD | $CLANG_FORMAT_DIFF -i -p 1
+  git diff -U0 HEAD -- $EXCLUDE | $CLANG_FORMAT_DIFF -i -p 1
 fi
 echo "Files reformatted!"
 
 # Amend to last commit if user do the post-commit format check
-if [ -z "$uncommitted_code" ]; then
+# Skip amend prompt in auto-apply mode (user can amend manually if desired)
+if [ -z "$uncommitted_code" ] && [ -z "$AUTO_APPLY" ]; then
   echo -e "Would you like to amend the changes to last commit (`git log HEAD --oneline | head -1`)? (y/n): \c"
   read to_amend
 

build_tools/getdeps_fallback_mirror.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+"""
+Pre-download packages with unreliable mirrors using fallback mirrors.
+Reads package info from folly's getdeps manifest files.
+"""
+import sys
+import os
+import hashlib
+import subprocess
+import configparser
+
+def sha256_file(path):
+    """Calculate SHA256 hash of a file."""
+    h = hashlib.sha256()
+    try:
+        with open(path, 'rb') as f:
+            for chunk in iter(lambda: f.read(65536), b''):
+                h.update(chunk)
+        return h.hexdigest()
+    except Exception:
+        return None
+
+def parse_manifest(manifest_path):
+    """Parse a getdeps manifest file to extract download info."""
+    config = configparser.ConfigParser()
+    try:
+        config.read(manifest_path)
+        if 'download' in config:
+            return {
+                'url': config['download'].get('url', ''),
+                'sha256': config['download'].get('sha256', ''),
+            }
+    except Exception:
+        pass
+    return None
+
+def get_fallback_mirrors(url):
+    """Get fallback mirror URLs for a given URL."""
+    # Fallback mirror patterns for known unreliable hosts
+    mirror_fallbacks = {
+        "ftp.gnu.org/gnu/": [
+            "https://mirrors.kernel.org/gnu/",
+            "https://ftpmirror.gnu.org/gnu/",
+            "https://ftp.gnu.org/gnu/",
+        ],
+        "ftpmirror.gnu.org/gnu/": [
+            "https://mirrors.kernel.org/gnu/",
+            "https://ftpmirror.gnu.org/gnu/",
+            "https://ftp.gnu.org/gnu/",
+        ],
+    }
+
+    for pattern, mirrors in mirror_fallbacks.items():
+        if pattern in url:
+            # Extract the path after the pattern
+            path_start = url.find(pattern) + len(pattern)
+            path = url[path_start:]
+            return [mirror + path for mirror in mirrors]
+    return [url]  # No fallback, use original
+
+def main():
+    if len(sys.argv) != 4:
+        print(f"Usage: {sys.argv[0]} <download_dir> <cache_dir> <manifests_dir>")
+        sys.exit(1)
+
+    download_dir, cache_dir, manifests_dir = sys.argv[1], sys.argv[2], sys.argv[3]
+
+    # Packages known to have unreliable mirrors
+    packages_to_check = ["autoconf", "automake", "libtool"]
+
+    for package in packages_to_check:
+        manifest_path = os.path.join(manifests_dir, package)
+        if not os.path.exists(manifest_path):
+            continue
+
+        info = parse_manifest(manifest_path)
+        if not info or not info['url'] or not info['sha256']:
+            continue
+
+        # Determine filename from URL
+        url = info['url']
+        expected_sha256 = info['sha256']
+        url_filename = os.path.basename(url)
+
+        # getdeps uses format: {package}-{filename}
+        filename = f"{package}-{url_filename}"
+        filepath = os.path.join(download_dir, filename)
+        cache_path = os.path.join(cache_dir, filename)
+
+        # Check if already valid
+        if os.path.exists(filepath) and sha256_file(filepath) == expected_sha256:
+            print(f"  {filename}: OK (already downloaded)")
+            continue
+
+        # Check cache
+        if os.path.exists(cache_path) and sha256_file(cache_path) == expected_sha256:
+            print(f"  {filename}: OK (from cache)")
+            subprocess.run(['cp', cache_path, filepath], check=True)
+            continue
+
+        # Try fallback mirrors
+        mirrors = get_fallback_mirrors(url)
+        downloaded = False
+        for mirror_url in mirrors:
+            print(f"  {filename}: trying {mirror_url}...")
+            try:
+                subprocess.run(['wget', '-q', '-O', filepath, mirror_url], check=True, timeout=120)
+                if sha256_file(filepath) == expected_sha256:
+                    print(f"  {filename}: OK (downloaded)")
+                    subprocess.run(['cp', filepath, cache_path], check=False)
+                    downloaded = True
+                    break
+                else:
+                    os.remove(filepath)
+            except Exception:
+                if os.path.exists(filepath):
+                    os.remove(filepath)
+
+        if not downloaded:
+            print(f"  {filename}: WARNING - all mirrors failed")
+
+if __name__ == "__main__":
+    main()

build_tools/gnu_parallel

@@ -1913,7 +1913,7 @@ sub drain_job_queue {
                     }
                     $last_progress_time = time();
                     $ps_reported = 0;
-                } elsif (not $ps_reported and (time() - $last_progress_time) >= 60) {
+                } elsif (not $ps_reported and (time() - $last_progress_time) >= 300) {
                     # No progress in at least 60 seconds: run ps
                     print $Global::original_stderr "\n";
                     my $script_dir = ::dirname($0);

build_tools/ubuntu22_image/Dockerfile

@@ -0,0 +1,90 @@
+# INSTRUCTIONS:
+# I was not able to build docker images on an isolated devserver because of
+# issues with proxy internet access. Use a public cloud or other Linux system.
+# (I used a Debian system after installing docker features, adding my user to
+# the docker and docker-registry groups, and logging out and back in to pick
+# those up.)
+#
+# Meta employees: see https://fburl.com/rocksdb-docker to build this on a devvm.
+#
+# Follow https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry#authenticating-with-a-personal-access-token-classic
+# to login with your GitHub credentials, as in
+#
+# $ docker login ghcr.io -u pdillinger
+#
+# and paste the limited-purpose GitHub token into the terminal.
+#
+# Then in the build_tools/ubuntu22_image directory, (bump minor version for
+# random docker file updates, major version tracks Ubuntu release)
+#
+# $ docker build -t ghcr.io/facebook/rocksdb_ubuntu:22.2
+# $ docker push ghcr.io/facebook/rocksdb_ubuntu:22.2
+#
+# Might need to change visibility to public through
+# https://github.com/orgs/facebook/packages/container/rocksdb_ubuntu/settings
+# or similar.
+
+# from official ubuntu 22.04
+FROM ubuntu:22.04
+# update system
+RUN apt-get update
+RUN apt-get upgrade -y
+# install basic tools
+RUN apt-get install -y vim wget curl ccache
+# install tzdata noninteractive
+RUN DEBIAN_FRONTEND=noninteractive TZ=Etc/UTC apt-get -y install tzdata
+# install git and default compilers
+RUN apt-get install -y git gcc g++ clang clang-tools
+# install basic package
+RUN apt-get install -y lsb-release software-properties-common gnupg
+# install gflags, tbb
+RUN apt-get install -y libgflags-dev libtbb-dev
+# install compression libs
+RUN apt-get install -y libsnappy-dev zlib1g-dev libbz2-dev liblz4-dev libzstd-dev
+# install cmake
+RUN apt-get install -y cmake
+RUN apt-get install -y libssl-dev
+# install clang-13
+WORKDIR /root
+RUN wget https://apt.llvm.org/llvm.sh
+RUN chmod +x llvm.sh
+RUN ./llvm.sh 13 all
+# There are incompatibilities between clang with -std=c++20 and libstdc++
+# provided by gcc, so we have to compile with clang-13 using -stdlib=libc++
+# and only one version of libc++ can be installed on the system at one time.
+# So to avoid confusion we remove unusable clang-14 also.
+RUN apt-get install libc++-13-dev libc++abi-13-dev
+RUN apt-get purge -y clang-14 && apt-get autoremove -y
+
+# install gcc-10 and more, default is 11
+RUN apt-get install -y gcc-10 g++-10
+RUN add-apt-repository -y ppa:ubuntu-toolchain-r/test
+RUN apt-get install -y gcc-13 g++-13
+# install apt-get install -y valgrind
+RUN apt-get install -y valgrind
+# install folly depencencies
+# Missing compatible libunwind: RUN apt-get install -y libgoogle-glog-dev
+# So instead install from source. This currently requires compiling with
+# -DGLOG_USE_GLOG_EXPORT
+RUN wget https://github.com/google/glog/archive/refs/tags/v0.7.1.tar.gz && tar xzf v0.7.1.tar.gz && cd glog-0.7.1/ && cmake -S . -B build -G "Unix Makefiles" && cmake --build build && cmake --build build --target install && cd .. && rm -rf v0.7.1.tar.gz glog-0.7.1
+# install openjdk 8
+RUN apt-get install -y openjdk-8-jdk
+ENV JAVA_HOME /usr/lib/jvm/java-1.8.0-openjdk-amd64
+# install mingw
+RUN apt-get install -y mingw-w64
+
+# install gtest-parallel package
+RUN git clone --single-branch --branch master --depth 1 https://github.com/google/gtest-parallel.git ~/gtest-parallel
+ENV PATH $PATH:/root/gtest-parallel
+
+# install libprotobuf for fuzzers test
+RUN apt-get install -y ninja-build binutils liblzma-dev libz-dev pkg-config autoconf libtool
+RUN git clone --branch v1.0 https://github.com/google/libprotobuf-mutator.git ~/libprotobuf-mutator && cd ~/libprotobuf-mutator && git checkout ffd86a32874e5c08a143019aad1aaf0907294c9f && mkdir build && cd build && cmake .. -GNinja -DCMAKE_C_COMPILER=clang-13 -DCMAKE_CXX_COMPILER=clang++-13 -DCMAKE_BUILD_TYPE=Release -DLIB_PROTO_MUTATOR_DOWNLOAD_PROTOBUF=ON && ninja && ninja install
+ENV PKG_CONFIG_PATH /usr/local/OFF/:/root/libprotobuf-mutator/build/external.protobuf/lib/pkgconfig/
+ENV PROTOC_BIN /root/libprotobuf-mutator/build/external.protobuf/bin/protoc
+
+# install the latest google benchmark
+RUN git clone --depth 1 --branch v1.7.0 https://github.com/google/benchmark.git ~/benchmark && cd ~/benchmark && mkdir build && cd build && cmake .. -GNinja -DCMAKE_BUILD_TYPE=Release -DBENCHMARK_ENABLE_GTEST_TESTS=0 && ninja && ninja install && cd ~ && rm -rf /root/benchmark
+
+# clean up
+RUN rm -rf /var/lib/apt/lists/*

build_tools/ubuntu24_image/Dockerfile

@@ -0,0 +1,78 @@
+# INSTRUCTIONS:
+# I was not able to build docker images on an isolated devserver because of
+# issues with proxy internet access. Use a public cloud or other Linux system.
+# (I used a Debian system after installing docker features, adding my user to
+# the docker and docker-registry groups, and logging out and back in to pick
+# those up.)
+#
+# Meta employees: see https://fburl.com/rocksdb-docker to build this on a devvm.
+#
+# Follow https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry#authenticating-with-a-personal-access-token-classic
+# to login with your GitHub credentials, as in
+#
+# $ docker login ghcr.io -u pdillinger
+#
+# and paste the limited-purpose GitHub token into the terminal.
+#
+# Then in the build_tools/ubuntu24_image directory, (bump minor version for
+# random docker file updates, major version tracks Ubuntu release)
+#
+# $ docker build -t ghcr.io/facebook/rocksdb_ubuntu:24.1
+# $ docker push ghcr.io/facebook/rocksdb_ubuntu:24.1
+#
+# Might need to change visibility to public through
+# https://github.com/orgs/facebook/packages/container/rocksdb_ubuntu/settings
+# or similar.
+
+# from official ubuntu 24.04
+FROM ubuntu:24.04
+# update system
+RUN apt-get update
+RUN apt-get upgrade -y
+# install basic tools
+RUN apt-get install -y vim wget curl ccache
+# install tzdata noninteractive
+RUN DEBIAN_FRONTEND=noninteractive TZ=Etc/UTC apt-get -y install tzdata
+# install git and default compilers
+RUN apt-get install -y git gcc g++ clang clang-tools
+# install clang-21 from LLVM snapshot repo
+RUN curl -fsSL https://apt.llvm.org/llvm-snapshot.gpg.key | gpg --dearmor -o /etc/apt/trusted.gpg.d/llvm.gpg && \
+    echo "deb https://apt.llvm.org/noble/ llvm-toolchain-noble-21 main" > /etc/apt/sources.list.d/llvm-21.list && \
+    apt-get update && apt-get install -y clang-21
+# install basic package
+RUN apt-get install -y lsb-release software-properties-common gnupg
+# install gflags, tbb
+RUN apt-get install -y libgflags-dev libtbb-dev
+# install compression libs
+RUN apt-get install -y libsnappy-dev zlib1g-dev libbz2-dev liblz4-dev libzstd-dev
+# install cmake
+RUN apt-get install -y cmake
+RUN apt-get install -y libssl-dev
+
+# install gcc-12 and more, default is 13
+RUN apt-get install -y gcc-12 g++-12 gcc-14 g++-14
+# install apt-get install -y valgrind
+RUN apt-get install -y valgrind
+# install folly depencencies
+RUN apt-get install -y libgoogle-glog-dev
+# install openjdk 8
+RUN apt-get install -y openjdk-8-jdk
+ENV JAVA_HOME /usr/lib/jvm/java-1.8.0-openjdk-amd64
+# install mingw
+RUN apt-get install -y mingw-w64
+
+# install gtest-parallel package
+RUN git clone --single-branch --branch master --depth 1 https://github.com/google/gtest-parallel.git ~/gtest-parallel
+ENV PATH $PATH:/root/gtest-parallel
+
+# install libprotobuf for fuzzers test
+RUN apt-get install -y ninja-build binutils liblzma-dev libz-dev pkg-config autoconf libtool
+RUN git clone --branch v1.0 https://github.com/google/libprotobuf-mutator.git ~/libprotobuf-mutator && cd ~/libprotobuf-mutator && git checkout ffd86a32874e5c08a143019aad1aaf0907294c9f && mkdir build && cd build && cmake .. -GNinja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release -DLIB_PROTO_MUTATOR_DOWNLOAD_PROTOBUF=ON && ninja && ninja install
+ENV PKG_CONFIG_PATH /usr/local/OFF/:/root/libprotobuf-mutator/build/external.protobuf/lib/pkgconfig/
+ENV PROTOC_BIN /root/libprotobuf-mutator/build/external.protobuf/bin/protoc
+
+# install the latest google benchmark
+RUN git clone --depth 1 --branch v1.7.0 https://github.com/google/benchmark.git ~/benchmark && cd ~/benchmark && mkdir build && cd build && cmake .. -GNinja -DCMAKE_BUILD_TYPE=Release -DBENCHMARK_ENABLE_GTEST_TESTS=0 && ninja && ninja install && cd ~ && rm -rf /root/benchmark
+
+# clean up
+RUN rm -rf /var/lib/apt/lists/*

build_tools/update_dependencies.sh

@@ -101,6 +101,5 @@ get_lib_base benchmark  LATEST  platform010
 get_lib_base kernel-headers fb platform010
 get_lib_base binutils   LATEST centos8-native
 get_lib_base valgrind   LATEST platform010
-get_lib_base lua        5.3.4  platform010
 
 git diff $OUTPUT

cache/cache.cc

@@ -54,11 +54,6 @@ static std::unordered_map<std::string, OptionTypeInfo>
          {offsetof(struct CompressedSecondaryCacheOptions, compression_type),
           OptionType::kCompressionType, OptionVerificationType::kNormal,
           OptionTypeFlags::kMutable}},
-        {"compress_format_version",
-         {offsetof(struct CompressedSecondaryCacheOptions,
-                   compress_format_version),
-          OptionType::kUInt32T, OptionVerificationType::kNormal,
-          OptionTypeFlags::kMutable}},
         {"enable_custom_split_merge",
          {offsetof(struct CompressedSecondaryCacheOptions,
                    enable_custom_split_merge),

cache/cache_bench_tool.cc

@@ -60,6 +60,8 @@ DEFINE_uint32(value_bytes, 8 * KiB, "Size of each value added.");
 DEFINE_uint32(value_bytes_estimate, 0,
               "If > 0, overrides estimated_entry_charge or "
               "min_avg_entry_charge depending on cache_type.");
+DEFINE_double(compressible_to_ratio, 0.5,
+              "Approximate size ratio that values can be compressed to.");
 
 DEFINE_int32(
     degenerate_hash_bits, 0,
@@ -117,7 +119,7 @@ DEFINE_uint32(seed, 0, "Hashing/random seed to use. 0 = choose at random");
 DEFINE_string(secondary_cache_uri, "",
               "Full URI for creating a custom secondary cache object");
 
-DEFINE_string(cache_type, "lru_cache", "Type of block cache.");
+DEFINE_string(cache_type, "hyper_clock_cache", "Type of block cache.");
 
 DEFINE_bool(use_jemalloc_no_dump_allocator, false,
             "Whether to use JemallocNoDumpAllocator");
@@ -182,6 +184,11 @@ DEFINE_bool(sck_randomize, false,
 DEFINE_bool(sck_footer_unique_id, false,
             "(-stress_cache_key) Simulate using proposed footer unique id");
 // ## END stress_cache_key sub-tool options ##
+// ## BEGIN stress_cache_instances sub-tool options ##
+DEFINE_uint32(stress_cache_instances, 0,
+              "If > 0, run cache instance stress test instead");
+// Uses cache_size and cache_type, maybe more
+// ## END stress_cache_instance sub-tool options ##
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -291,10 +298,19 @@ struct KeyGen {
 
 Cache::ObjectPtr createValue(Random64& rnd, MemoryAllocator* alloc) {
   char* rv = AllocateBlock(FLAGS_value_bytes, alloc).release();
-  // Fill with some filler data, and take some CPU time
-  for (uint32_t i = 0; i < FLAGS_value_bytes; i += 8) {
+  // Fill with some filler data, and take some CPU time, but add redundancy
+  // as requested for compressibility.
+  uint32_t random_fill_size = std::max(
+      uint32_t{1}, std::min(FLAGS_value_bytes,
+                            static_cast<uint32_t>(FLAGS_compressible_to_ratio *
+                                                  FLAGS_value_bytes)));
+  uint32_t i = 0;
+  for (; i < random_fill_size; i += 8) {
     EncodeFixed64(rv + i, rnd.Next());
   }
+  for (; i < FLAGS_value_bytes; i++) {
+    rv[i] = rv[i % random_fill_size];
+  }
   return rv;
 }
 
@@ -309,16 +325,16 @@ Status SaveToFn(Cache::ObjectPtr from_obj, size_t /*from_offset*/,
 
 Status CreateFn(const Slice& data, CompressionType /*type*/,
                 CacheTier /*source*/, Cache::CreateContext* /*context*/,
-                MemoryAllocator* /*allocator*/, Cache::ObjectPtr* out_obj,
+                MemoryAllocator* alloc, Cache::ObjectPtr* out_obj,
                 size_t* out_charge) {
-  *out_obj = new char[data.size()];
+  *out_obj = AllocateBlock(data.size(), alloc).release();
   memcpy(*out_obj, data.data(), data.size());
   *out_charge = data.size();
   return Status::OK();
 };
 
 void DeleteFn(Cache::ObjectPtr value, MemoryAllocator* alloc) {
-  CustomDeleter{alloc}(static_cast<char*>(value));
+  CacheAllocationDeleter{alloc}(static_cast<char*>(value));
 }
 
 Cache::CacheItemHelper helper1_wos(CacheEntryRole::kDataBlock, DeleteFn);
@@ -376,7 +392,12 @@ class CacheBench {
       fprintf(stderr, "Percentages must add to 100.\n");
       exit(1);
     }
+    cache_ = MakeCache();
+  }
 
+  ~CacheBench() = default;
+
+  static std::shared_ptr<Cache> MakeCache() {
     std::shared_ptr<MemoryAllocator> allocator;
     if (FLAGS_use_jemalloc_no_dump_allocator) {
       JemallocAllocatorOptions opts;
@@ -395,12 +416,12 @@ class CacheBench {
       opts.hash_seed = BitwiseAnd(FLAGS_seed, INT32_MAX);
       opts.memory_allocator = allocator;
       opts.eviction_effort_cap = FLAGS_eviction_effort_cap;
-      if (FLAGS_cache_type == "fixed_hyper_clock_cache" ||
-          FLAGS_cache_type == "hyper_clock_cache") {
+      if (FLAGS_cache_type == "fixed_hyper_clock_cache") {
         opts.estimated_entry_charge = FLAGS_value_bytes_estimate > 0
                                           ? FLAGS_value_bytes_estimate
                                           : FLAGS_value_bytes;
-      } else if (FLAGS_cache_type == "auto_hyper_clock_cache") {
+      } else if (FLAGS_cache_type == "auto_hyper_clock_cache" ||
+                 FLAGS_cache_type == "hyper_clock_cache") {
         if (FLAGS_value_bytes_estimate > 0) {
           opts.min_avg_entry_charge = FLAGS_value_bytes_estimate;
         }
@@ -409,7 +430,7 @@ class CacheBench {
         exit(1);
       }
       ConfigureSecondaryCache(opts);
-      cache_ = opts.MakeSharedCache();
+      return opts.MakeSharedCache();
     } else if (FLAGS_cache_type == "lru_cache") {
       LRUCacheOptions opts(FLAGS_cache_size, FLAGS_num_shard_bits,
                            false /* strict_capacity_limit */,
@@ -417,15 +438,13 @@ class CacheBench {
       opts.hash_seed = BitwiseAnd(FLAGS_seed, INT32_MAX);
       opts.memory_allocator = allocator;
       ConfigureSecondaryCache(opts);
-      cache_ = NewLRUCache(opts);
+      return NewLRUCache(opts);
     } else {
       fprintf(stderr, "Cache type not supported.\n");
       exit(1);
     }
   }
 
-  ~CacheBench() = default;
-
   void PopulateCache() {
     Random64 rnd(FLAGS_seed);
     KeyGen keygen;
@@ -479,7 +498,7 @@ class CacheBench {
 
     PrintEnv();
     SharedState shared(this);
-    std::vector<std::unique_ptr<ThreadState> > threads(FLAGS_threads);
+    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();
@@ -1141,6 +1160,59 @@ class StressCacheKey {
   double multiplier_ = 0.0;
 };
 
+// cache_bench -stress_cache_instances is a partially independent embedded tool
+// for evaluating the time and space required to create and destroy many cache
+// instances, as this is considered important for a default cache implementation
+// which could see many throw-away instances in handling of Options, or created
+// in large numbers for many very small DBs with many CFs. Prefix command line
+// with /usr/bin/time to see max RSS memory.
+class StressCacheInstances {
+ public:
+  void Run() {
+    const int kNumIterations = 10;
+    const auto clock = SystemClock::Default().get();
+    caches_.reserve(FLAGS_stress_cache_instances);
+
+    uint64_t total_create_time_us = 0;
+    uint64_t total_destroy_time_us = 0;
+
+    for (int iter = 0; iter < kNumIterations; ++iter) {
+      // Create many cache instances
+      uint64_t start_create = clock->NowMicros();
+      for (uint32_t i = 0; i < FLAGS_stress_cache_instances; ++i) {
+        caches_.emplace_back(CacheBench::MakeCache());
+      }
+      uint64_t end_create = clock->NowMicros();
+      uint64_t create_time = end_create - start_create;
+      total_create_time_us += create_time;
+
+      // Destroy them
+      uint64_t start_destroy = clock->NowMicros();
+      caches_.clear();
+      uint64_t end_destroy = clock->NowMicros();
+      uint64_t destroy_time = end_destroy - start_destroy;
+      total_destroy_time_us += destroy_time;
+
+      printf(
+          "Iteration %d: Created %u caches in %.3f ms, destroyed in %.3f ms\n",
+          iter + 1, FLAGS_stress_cache_instances, create_time / 1000.0,
+          destroy_time / 1000.0);
+    }
+
+    printf("Average creation time: %.3f ms (%.1f us per cache)\n",
+           static_cast<double>(total_create_time_us) / kNumIterations / 1000.0,
+           static_cast<double>(total_create_time_us) / kNumIterations /
+               FLAGS_stress_cache_instances);
+    printf("Average destruction time: %.3f ms (%.1f us per cache)\n",
+           static_cast<double>(total_destroy_time_us) / kNumIterations / 1000.0,
+           static_cast<double>(total_destroy_time_us) / kNumIterations /
+               FLAGS_stress_cache_instances);
+  }
+
+ private:
+  std::vector<std::shared_ptr<Cache>> caches_;
+};
+
 int cache_bench_tool(int argc, char** argv) {
   ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
   ParseCommandLineFlags(&argc, &argv, true);
@@ -1151,6 +1223,11 @@ int cache_bench_tool(int argc, char** argv) {
     return 0;
   }
 
+  if (FLAGS_stress_cache_instances > 0) {
+    StressCacheInstances().Run();
+    return 0;
+  }
+
   if (FLAGS_threads <= 0) {
     fprintf(stderr, "threads number <= 0\n");
     exit(1);

cache/cache_entry_stats.h

@@ -101,23 +101,23 @@ class CacheEntryStatsCollector {
   }
 
   // Gets saved stats, regardless of age
-  void GetStats(Stats *stats) {
+  void GetStats(Stats* stats) {
     std::lock_guard<std::mutex> lock(saved_mutex_);
     *stats = saved_stats_;
   }
 
-  Cache *GetCache() const { return cache_; }
+  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 *raw_cache, SystemClock *clock,
-                          std::shared_ptr<CacheEntryStatsCollector> *ptr) {
+  static Status GetShared(Cache* raw_cache, SystemClock* clock,
+                          std::shared_ptr<CacheEntryStatsCollector>* ptr) {
     assert(raw_cache);
     BasicTypedCacheInterface<CacheEntryStatsCollector, CacheEntryRole::kMisc>
         cache{raw_cache};
 
-    const Slice &cache_key = GetCacheKey();
+    const Slice& cache_key = GetCacheKey();
     auto h = cache.Lookup(cache_key);
     if (h == nullptr) {
       // Not yet in cache, but Cache doesn't provide a built-in way to
@@ -152,7 +152,7 @@ class CacheEntryStatsCollector {
   }
 
  private:
-  explicit CacheEntryStatsCollector(Cache *cache, SystemClock *clock)
+  explicit CacheEntryStatsCollector(Cache* cache, SystemClock* clock)
       : saved_stats_(),
         working_stats_(),
         last_start_time_micros_(0),
@@ -160,7 +160,7 @@ class CacheEntryStatsCollector {
         cache_(cache),
         clock_(clock) {}
 
-  static const Slice &GetCacheKey() {
+  static const Slice& GetCacheKey() {
     // For each template instantiation
     static CacheKey ckey = CacheKey::CreateUniqueForProcessLifetime();
     static Slice ckey_slice = ckey.AsSlice();
@@ -175,8 +175,8 @@ class CacheEntryStatsCollector {
   uint64_t last_start_time_micros_;
   uint64_t last_end_time_micros_;
 
-  Cache *const cache_;
-  SystemClock *const clock_;
+  Cache* const cache_;
+  SystemClock* const clock_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

cache/cache_key.cc

@@ -24,7 +24,7 @@ namespace ROCKSDB_NAMESPACE {
 //              0 |      >= 1<<63 | CreateUniqueForProcessLifetime
 //            > 0 |           any | OffsetableCacheKey.WithOffset
 
-CacheKey CacheKey::CreateUniqueForCacheLifetime(Cache *cache) {
+CacheKey CacheKey::CreateUniqueForCacheLifetime(Cache* cache) {
   // +1 so that we can reserve all zeros for "unset" cache key
   uint64_t id = cache->NewId() + 1;
   // Ensure we don't collide with CreateUniqueForProcessLifetime
@@ -297,8 +297,8 @@ CacheKey CacheKey::CreateUniqueForProcessLifetime() {
 //
 // TODO: Nevertheless / regardless, an efficient way to detect (and thus
 // quantify) block cache corruptions, including collisions, should be added.
-OffsetableCacheKey::OffsetableCacheKey(const std::string &db_id,
-                                       const std::string &db_session_id,
+OffsetableCacheKey::OffsetableCacheKey(const std::string& db_id,
+                                       const std::string& db_session_id,
                                        uint64_t file_number) {
   UniqueId64x2 internal_id;
   Status s = GetSstInternalUniqueId(db_id, db_session_id, file_number,

cache/cache_key.h

@@ -44,13 +44,13 @@ class CacheKey {
   inline Slice AsSlice() const {
     static_assert(sizeof(*this) == 16, "Standardized on 16-byte cache key");
     assert(!IsEmpty());
-    return Slice(reinterpret_cast<const char *>(this), sizeof(*this));
+    return Slice(reinterpret_cast<const char*>(this), sizeof(*this));
   }
 
   // Create a CacheKey that is unique among others associated with this Cache
   // instance. Depends on Cache::NewId. This is useful for block cache
   // "reservations".
-  static CacheKey CreateUniqueForCacheLifetime(Cache *cache);
+  static CacheKey CreateUniqueForCacheLifetime(Cache* cache);
 
   // Create a CacheKey that is unique among others for the lifetime of this
   // process. This is useful for saving in a static data member so that
@@ -87,7 +87,7 @@ class OffsetableCacheKey : private CacheKey {
 
   // Constructs an OffsetableCacheKey with the given information about a file.
   // This constructor never generates an "empty" base key.
-  OffsetableCacheKey(const std::string &db_id, const std::string &db_session_id,
+  OffsetableCacheKey(const std::string& db_id, const std::string& db_session_id,
                      uint64_t file_number);
 
   // Creates an OffsetableCacheKey from an SST unique ID, so that cache keys
@@ -134,9 +134,9 @@ class OffsetableCacheKey : private CacheKey {
     static_assert(sizeof(file_num_etc64_) == kCommonPrefixSize,
                   "8 byte common prefix expected");
     assert(!IsEmpty());
-    assert(&this->file_num_etc64_ == static_cast<const void *>(this));
+    assert(&this->file_num_etc64_ == static_cast<const void*>(this));
 
-    return Slice(reinterpret_cast<const char *>(this), kCommonPrefixSize);
+    return Slice(reinterpret_cast<const char*>(this), kCommonPrefixSize);
   }
 };
 

cache/cache_reservation_manager.h

@@ -44,8 +44,8 @@ class CacheReservationManager {
                                         bool increase) = 0;
   virtual Status MakeCacheReservation(
       std::size_t incremental_memory_used,
-      std::unique_ptr<CacheReservationManager::CacheReservationHandle>
-          *handle) = 0;
+      std::unique_ptr<CacheReservationManager::CacheReservationHandle>*
+          handle) = 0;
   virtual std::size_t GetTotalReservedCacheSize() = 0;
   virtual std::size_t GetTotalMemoryUsed() = 0;
 };
@@ -90,11 +90,11 @@ class CacheReservationManagerImpl
                                        bool delayed_decrease = false);
 
   // no copy constructor, copy assignment, move constructor, move assignment
-  CacheReservationManagerImpl(const CacheReservationManagerImpl &) = delete;
-  CacheReservationManagerImpl &operator=(const CacheReservationManagerImpl &) =
+  CacheReservationManagerImpl(const CacheReservationManagerImpl&) = delete;
+  CacheReservationManagerImpl& operator=(const CacheReservationManagerImpl&) =
       delete;
-  CacheReservationManagerImpl(CacheReservationManagerImpl &&) = delete;
-  CacheReservationManagerImpl &operator=(CacheReservationManagerImpl &&) =
+  CacheReservationManagerImpl(CacheReservationManagerImpl&&) = delete;
+  CacheReservationManagerImpl& operator=(CacheReservationManagerImpl&&) =
       delete;
 
   ~CacheReservationManagerImpl() override;
@@ -178,7 +178,7 @@ class CacheReservationManagerImpl
   // REQUIRES: handle != nullptr
   Status MakeCacheReservation(
       std::size_t incremental_memory_used,
-      std::unique_ptr<CacheReservationManager::CacheReservationHandle> *handle)
+      std::unique_ptr<CacheReservationManager::CacheReservationHandle>* handle)
       override;
 
   // Return the size of the cache (which is a multiple of kSizeDummyEntry)
@@ -200,7 +200,7 @@ class CacheReservationManagerImpl
   // For testing only - it is to help ensure the CacheItemHelperForRole<R>
   // accessed from CacheReservationManagerImpl and the one accessed from the
   // test are from the same translation units
-  static const Cache::CacheItemHelper *TEST_GetCacheItemHelperForRole();
+  static const Cache::CacheItemHelper* TEST_GetCacheItemHelperForRole();
 
  private:
   static constexpr std::size_t kSizeDummyEntry = 256 * 1024;
@@ -216,7 +216,7 @@ class CacheReservationManagerImpl
   bool delayed_decrease_;
   std::atomic<std::size_t> cache_allocated_size_;
   std::size_t memory_used_;
-  std::vector<Cache::Handle *> dummy_handles_;
+  std::vector<Cache::Handle*> dummy_handles_;
   CacheKey cache_key_;
 };
 
@@ -251,14 +251,14 @@ class ConcurrentCacheReservationManager
       std::shared_ptr<CacheReservationManager> cache_res_mgr) {
     cache_res_mgr_ = std::move(cache_res_mgr);
   }
-  ConcurrentCacheReservationManager(const ConcurrentCacheReservationManager &) =
+  ConcurrentCacheReservationManager(const ConcurrentCacheReservationManager&) =
       delete;
-  ConcurrentCacheReservationManager &operator=(
-      const ConcurrentCacheReservationManager &) = delete;
-  ConcurrentCacheReservationManager(ConcurrentCacheReservationManager &&) =
+  ConcurrentCacheReservationManager& operator=(
+      const ConcurrentCacheReservationManager&) = delete;
+  ConcurrentCacheReservationManager(ConcurrentCacheReservationManager&&) =
       delete;
-  ConcurrentCacheReservationManager &operator=(
-      ConcurrentCacheReservationManager &&) = delete;
+  ConcurrentCacheReservationManager& operator=(
+      ConcurrentCacheReservationManager&&) = delete;
 
   ~ConcurrentCacheReservationManager() override {}
 
@@ -286,7 +286,7 @@ class ConcurrentCacheReservationManager
 
   inline Status MakeCacheReservation(
       std::size_t incremental_memory_used,
-      std::unique_ptr<CacheReservationManager::CacheReservationHandle> *handle)
+      std::unique_ptr<CacheReservationManager::CacheReservationHandle>* handle)
       override {
     std::unique_ptr<CacheReservationManager::CacheReservationHandle>
         wrapped_handle;

cache/cache_test.cc

@@ -644,7 +644,7 @@ using TypedHandle = SharedCache::TypedHandle;
 
 TEST_P(CacheTest, SetCapacity) {
   if (IsHyperClock()) {
-    // TODO: update test & code for limited supoort
+    // TODO: update test & code for limited support
     ROCKSDB_GTEST_BYPASS(
         "HyperClockCache doesn't support arbitrary capacity "
         "adjustments.");

cache/clock_cache.h

@@ -9,8 +9,6 @@
 
 #pragma once
 
-#include <array>
-#include <atomic>
 #include <climits>
 #include <cstddef>
 #include <cstdint>
@@ -19,14 +17,10 @@
 
 #include "cache/cache_key.h"
 #include "cache/sharded_cache.h"
-#include "port/lang.h"
-#include "port/malloc.h"
 #include "port/mmap.h"
-#include "port/port.h"
 #include "rocksdb/cache.h"
-#include "rocksdb/secondary_cache.h"
 #include "util/atomic.h"
-#include "util/autovector.h"
+#include "util/bit_fields.h"
 #include "util/math.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -323,40 +317,89 @@ struct ClockHandle : public ClockHandleBasicData {
   // | acquire counter      | release counter     | hit bit | state marker |
   // -----------------------------------------------------------------------
 
-  // For reading or updating counters in meta word.
-  static constexpr uint8_t kCounterNumBits = 30;
-  static constexpr uint64_t kCounterMask = (uint64_t{1} << kCounterNumBits) - 1;
+  struct SlotMeta : public BitFields<uint64_t, SlotMeta> {
+    // For reading or updating counters in meta word.
+    static constexpr uint8_t kCounterNumBits = 30;
+    // Number of times the a reference has been acquired (or attempted)
+    // since last reset by eviction processing
+    using AcquireCounter =
+        UnsignedBitField<SlotMeta, kCounterNumBits, NoPrevBitField>;
+    // Number of times the a reference has been released (or attempted)
+    // since last reset by eviction processing
+    using ReleaseCounter =
+        UnsignedBitField<SlotMeta, kCounterNumBits, AcquireCounter>;
+    // Metadata bit in support of secondary cache
+    using HitFlag = BoolBitField<SlotMeta, ReleaseCounter>;
+    // Occupied means any state other than empty
+    using OccupiedFlag = BoolBitField<SlotMeta, HitFlag>;
+    // Shareable means the entry is reference counted (visible or invisible)
+    // (only set if also occupied)
+    using ShareableFlag = BoolBitField<SlotMeta, OccupiedFlag>;
+    // Visible is only set if also shareable (invisible can't be found by
+    // Lookup)
+    using VisibleFlag = BoolBitField<SlotMeta, ShareableFlag>;
 
-  static constexpr uint8_t kAcquireCounterShift = 0;
-  static constexpr uint64_t kAcquireIncrement = uint64_t{1}
-                                                << kAcquireCounterShift;
-  static constexpr uint8_t kReleaseCounterShift = kCounterNumBits;
-  static constexpr uint64_t kReleaseIncrement = uint64_t{1}
-                                                << kReleaseCounterShift;
+    // Convenience functions
+    uint32_t GetAcquireCounter() const { return Get<AcquireCounter>(); }
+    void SetAcquireCounter(uint32_t val) { Set<AcquireCounter>(val); }
+    uint32_t GetReleaseCounter() const { return Get<ReleaseCounter>(); }
+    void SetReleaseCounter(uint32_t val) { Set<ReleaseCounter>(val); }
+    uint32_t GetRefcount() const {
+      return Get<AcquireCounter>() - Get<ReleaseCounter>();
+    }
+    bool GetHit() const { return Get<HitFlag>(); }
+    void SetHit(bool val) { Set<HitFlag>(val); }
 
-  // For setting the hit bit
-  static constexpr uint8_t kHitBitShift = 2U * kCounterNumBits;
-  static constexpr uint64_t kHitBitMask = uint64_t{1} << kHitBitShift;
+    // Some distinct states for the various state flags
+    bool IsEmpty() const {
+      bool rv = !Get<OccupiedFlag>();
+      if (rv) {
+        assert(!Get<ShareableFlag>());
+        assert(!Get<VisibleFlag>());
+      }
+      return rv;
+    }
 
-  // For reading or updating the state marker in meta word
-  static constexpr uint8_t kStateShift = kHitBitShift + 1;
+    bool IsUnderConstruction() const {
+      bool rv = Get<OccupiedFlag>() && !Get<ShareableFlag>();
+      if (rv) {
+        assert(!Get<VisibleFlag>());
+      }
+      return rv;
+    }
+    void SetUnderConstruction() {
+      Set<OccupiedFlag>(true);
+      Set<ShareableFlag>(false);
+      Set<VisibleFlag>(false);
+    }
 
-  // Bits contribution to state marker.
-  // Occupied means any state other than empty
-  static constexpr uint8_t kStateOccupiedBit = 0b100;
-  // Shareable means the entry is reference counted (visible or invisible)
-  // (only set if also occupied)
-  static constexpr uint8_t kStateShareableBit = 0b010;
-  // Visible is only set if also shareable
-  static constexpr uint8_t kStateVisibleBit = 0b001;
+    bool IsShareable() const { return Get<ShareableFlag>(); }
+    bool IsInvisible() const {
+      bool rv = Get<ShareableFlag>() && !Get<VisibleFlag>();
+      if (rv) {
+        assert(Get<OccupiedFlag>());
+      }
+      return rv;
+    }
+    void SetInvisible() {
+      Set<OccupiedFlag>(true);
+      Set<ShareableFlag>(true);
+      Set<VisibleFlag>(false);
+    }
 
-  // Complete state markers (not shifted into full word)
-  static constexpr uint8_t kStateEmpty = 0b000;
-  static constexpr uint8_t kStateConstruction = kStateOccupiedBit;
-  static constexpr uint8_t kStateInvisible =
-      kStateOccupiedBit | kStateShareableBit;
-  static constexpr uint8_t kStateVisible =
-      kStateOccupiedBit | kStateShareableBit | kStateVisibleBit;
+    bool IsVisible() const {
+      bool rv = Get<ShareableFlag>() && Get<VisibleFlag>();
+      if (rv) {
+        assert(Get<OccupiedFlag>());
+      }
+      return rv;
+    }
+    void SetVisible() {
+      Set<OccupiedFlag>(true);
+      Set<ShareableFlag>(true);
+      Set<VisibleFlag>(true);
+    }
+  };
 
   // Constants for initializing the countdown clock. (Countdown clock is only
   // in effect with zero refs, acquire counter == release counter, and in that
@@ -370,7 +413,7 @@ struct ClockHandle : public ClockHandleBasicData {
   // TODO: make these coundown values tuning parameters for eviction?
 
   // See above. Mutable for read reference counting.
-  mutable AcqRelAtomic<uint64_t> meta{};
+  mutable BitFieldsAtomic<SlotMeta> meta{};
 };  // struct ClockHandle
 
 class BaseClockTable {
@@ -383,25 +426,20 @@ class BaseClockTable {
     int eviction_effort_cap;
   };
 
-  BaseClockTable(CacheMetadataChargePolicy metadata_charge_policy,
+  BaseClockTable(size_t capacity, bool strict_capacity_limit,
+                 int eviction_effort_cap,
+                 CacheMetadataChargePolicy metadata_charge_policy,
                  MemoryAllocator* allocator,
                  const Cache::EvictionCallback* eviction_callback,
-                 const uint32_t* hash_seed)
-      : metadata_charge_policy_(metadata_charge_policy),
-        allocator_(allocator),
-        eviction_callback_(*eviction_callback),
-        hash_seed_(*hash_seed) {}
+                 const uint32_t* hash_seed);
 
   template <class Table>
   typename Table::HandleImpl* CreateStandalone(ClockHandleBasicData& proto,
-                                               size_t capacity,
-                                               uint32_t eec_and_scl,
                                                bool allow_uncharged);
 
   template <class Table>
   Status Insert(const ClockHandleBasicData& proto,
-                typename Table::HandleImpl** handle, Cache::Priority priority,
-                size_t capacity, uint32_t eec_and_scl);
+                typename Table::HandleImpl** handle, Cache::Priority priority);
 
   void Ref(ClockHandle& handle);
 
@@ -411,6 +449,18 @@ class BaseClockTable {
 
   size_t GetStandaloneUsage() const { return standalone_usage_.LoadRelaxed(); }
 
+  size_t GetCapacity() const { return capacity_.LoadRelaxed(); }
+
+  void SetCapacity(size_t capacity) { capacity_.StoreRelaxed(capacity); }
+
+  void SetStrictCapacityLimit(bool strict_capacity_limit) {
+    if (strict_capacity_limit) {
+      eec_and_scl_.ApplyRelaxed(StrictCapacityLimit::SetTransform());
+    } else {
+      eec_and_scl_.ApplyRelaxed(StrictCapacityLimit::ClearTransform());
+    }
+  }
+
   uint32_t GetHashSeed() const { return hash_seed_; }
 
   uint64_t GetYieldCount() const { return yield_count_.LoadRelaxed(); }
@@ -427,11 +477,12 @@ class BaseClockTable {
 
   void TrackAndReleaseEvictedEntry(ClockHandle* h);
 
+  bool IsEvictionEffortExceeded(const BaseClockTable::EvictionData& data) const;
 #ifndef NDEBUG
   // Acquire N references
-  void TEST_RefN(ClockHandle& handle, size_t n);
+  void TEST_RefN(ClockHandle& handle, uint32_t n);
   // Helper for TEST_ReleaseN
-  void TEST_ReleaseNMinus1(ClockHandle* handle, size_t n);
+  void TEST_ReleaseNMinus1(ClockHandle* handle, uint32_t n);
 #endif
 
  private:  // fns
@@ -448,9 +499,8 @@ class BaseClockTable {
   // required, and the operation should fail if not possible.
   // NOTE: Otherwise, occupancy_ is not managed in this function
   template <class Table>
-  Status ChargeUsageMaybeEvictStrict(size_t total_charge, size_t capacity,
+  Status ChargeUsageMaybeEvictStrict(size_t total_charge,
                                      bool need_evict_for_occupancy,
-                                     uint32_t eviction_effort_cap,
                                      typename Table::InsertState& state);
 
   // Helper for updating `usage_` for new entry with given `total_charge`
@@ -462,9 +512,8 @@ class BaseClockTable {
   // true, indicating success.
   // NOTE: occupancy_ is not managed in this function
   template <class Table>
-  bool ChargeUsageMaybeEvictNonStrict(size_t total_charge, size_t capacity,
+  bool ChargeUsageMaybeEvictNonStrict(size_t total_charge,
                                       bool need_evict_for_occupancy,
-                                      uint32_t eviction_effort_cap,
                                       typename Table::InsertState& state);
 
  protected:  // data
@@ -489,13 +538,32 @@ class BaseClockTable {
   // TODO: is this separation needed if we don't do background evictions?
   ALIGN_AS(CACHE_LINE_SIZE)
   // Number of elements in the table.
-  AcqRelAtomic<size_t> occupancy_{};
+  Atomic<size_t> occupancy_{};
 
   // Memory usage by entries tracked by the cache (including standalone)
-  AcqRelAtomic<size_t> usage_{};
+  Atomic<size_t> usage_{};
 
   // Part of usage by standalone entries (not in table)
-  AcqRelAtomic<size_t> standalone_usage_{};
+  Atomic<size_t> standalone_usage_{};
+
+  // Maximum total charge of all elements stored in the table.
+  // (Relaxed: eventual consistency/update is OK)
+  RelaxedAtomic<size_t> capacity_;
+
+  // Encodes eviction_effort_cap (bottom 31 bits) and strict_capacity_limit
+  // (top bit). See HyperClockCacheOptions::eviction_effort_cap etc.
+  struct EecAndScl : public BitFields<uint32_t, EecAndScl> {
+    uint32_t GetEffectiveEvictionEffortCap() const {
+      // Because setting strict_capacity_limit is supposed to imply infinite
+      // cap on eviction effort, we can let the bit for strict_capacity_limit
+      // in the upper-most bit position to used as part of the effective cap.
+      return underlying;
+    }
+  };
+  using EvictionEffortCap = UnsignedBitField<EecAndScl, 31, NoPrevBitField>;
+  using StrictCapacityLimit = BoolBitField<EecAndScl, EvictionEffortCap>;
+  // (Relaxed: eventual consistency/update is OK)
+  RelaxedBitFieldsAtomic<EecAndScl> eec_and_scl_;
 
   ALIGN_AS(CACHE_LINE_SIZE)
   const CacheMetadataChargePolicy metadata_charge_policy_;
@@ -551,7 +619,7 @@ class FixedHyperClockTable : public BaseClockTable {
     size_t estimated_value_size;
   };
 
-  FixedHyperClockTable(size_t capacity,
+  FixedHyperClockTable(size_t capacity, bool strict_capacity_limit,
                        CacheMetadataChargePolicy metadata_charge_policy,
                        MemoryAllocator* allocator,
                        const Cache::EvictionCallback* eviction_callback,
@@ -567,14 +635,13 @@ class FixedHyperClockTable : public BaseClockTable {
   bool GrowIfNeeded(size_t new_occupancy, InsertState& state);
 
   HandleImpl* DoInsert(const ClockHandleBasicData& proto,
-                       uint64_t initial_countdown, bool take_ref,
+                       uint32_t initial_countdown, bool take_ref,
                        InsertState& state);
 
   // Runs the clock eviction algorithm trying to reclaim at least
   // requested_charge. Returns how much is evicted, which could be less
   // if it appears impossible to evict the requested amount without blocking.
-  void Evict(size_t requested_charge, InsertState& state, EvictionData* data,
-             uint32_t eviction_effort_cap);
+  void Evict(size_t requested_charge, InsertState& state, EvictionData* data);
 
   HandleImpl* Lookup(const UniqueId64x2& hashed_key);
 
@@ -596,7 +663,7 @@ class FixedHyperClockTable : public BaseClockTable {
   }
 
   // Release N references
-  void TEST_ReleaseN(HandleImpl* handle, size_t n);
+  void TEST_ReleaseN(HandleImpl* handle, uint32_t n);
 #endif
 
   // The load factor p is a real number in (0, 1) such that at all
@@ -757,6 +824,7 @@ class AutoHyperClockTable : public BaseClockTable {
     // chain--specifically the next entry in the chain.
     // * The end of a chain is given a special "end" marker and refers back
     // to the head of the chain.
+    // These decorated pointers use the NextWithShift bit field struct below.
     //
     // Why do we need shift on each pointer? To make Lookup wait-free, we need
     // to be able to query a chain without missing anything, and preferably
@@ -776,47 +844,63 @@ class AutoHyperClockTable : public BaseClockTable {
     // it is normal to see "under construction" entries on the chain, and it
     // is not safe to read their hashed key without either a read reference
     // on the entry or a rewrite lock on the chain.
+    struct NextWithShift : public BitFields<uint64_t, NextWithShift> {
+      // The "shift" associated with this decorated pointer (see description
+      // above).
+      using Shift = UnsignedBitField<NextWithShift, 6, NoPrevBitField>;
+      // Marker for the end of a chain. Must also (a) point back to the head of
+      // the chain (with end marker removed), and (b) set the LockedFlag
+      // (below), so that attempting to lock an empty chain has no effect (not
+      // needed, as the lock is only needed for removals).
+      using EndFlag = BoolBitField<NextWithShift, Shift>;
+      // Marker that some thread owning writes to the chain structure (except
+      // for inserts), but only if not an "end" pointer. Also called the
+      // "rewrite lock."
+      using LockedFlag = BoolBitField<NextWithShift, EndFlag>;
+      // The "next" associated with this decorated pointer, which is an index
+      // into the table's array_ (see description above).
+      using Next = UnsignedBitField<NextWithShift, 56, LockedFlag>;
 
-    // Marker in a "with_shift" head pointer for some thread owning writes
-    // to the chain structure (except for inserts), but only if not an
-    // "end" pointer. Also called the "rewrite lock."
-    static constexpr uint64_t kHeadLocked = uint64_t{1} << 7;
+      bool IsLocked() const { return Get<LockedFlag>(); }
+      bool IsEnd() const {
+        // End flag should imply locked flag
+        assert(!Get<EndFlag>() || Get<LockedFlag>());
+        return Get<EndFlag>();
+      }
+      bool IsLockedNotEnd() const {
+        // NOTE: helping GCC to optimize this simpler code:
+        // return IsLocked() && !IsEnd();
+        constexpr U kEndFlag = U{1} << EndFlag::kBitOffset;
+        constexpr U kLockedFlag = U{1} << LockedFlag::kBitOffset;
+        return (underlying & (kEndFlag | kLockedFlag)) == kLockedFlag;
+      }
+      auto GetNext() const { return Get<Next>(); }
+      auto GetShift() const { return Get<Shift>(); }
 
-    // Marker in a "with_shift" pointer for the end of a chain. Must also
-    // point back to the head of the chain (with end marker removed).
-    // Also includes the "locked" bit so that attempting to lock an empty
-    // chain has no effect (not needed, as the lock is only needed for
-    // removals).
-    static constexpr uint64_t kNextEndFlags = (uint64_t{1} << 6) | kHeadLocked;
+      static NextWithShift Make(size_t next, int shift) {
+        return NextWithShift{}.With<Next>(next).With<Shift>(
+            static_cast<uint8_t>(shift));
+      }
 
-    static inline bool IsEnd(uint64_t next_with_shift) {
-      // Assuming certain values never used, suffices to check this one bit
-      constexpr auto kCheckBit = kNextEndFlags ^ kHeadLocked;
-      return next_with_shift & kCheckBit;
-    }
-
-    // Bottom bits to right shift away to get an array index from a
-    // "with_shift" pointer.
-    static constexpr int kNextShift = 8;
-
-    // A bit mask for the "shift" associated with each "with_shift" pointer.
-    // Always bottommost bits.
-    static constexpr int kShiftMask = 63;
+      static NextWithShift MakeEnd(size_t next, int shift) {
+        return Make(next, shift).With<EndFlag>(true).With<LockedFlag>(true);
+      }
+    };
 
     // A marker for head_next_with_shift that indicates this HandleImpl is
     // heap allocated (standalone) rather than in the table.
-    static constexpr uint64_t kStandaloneMarker = UINT64_MAX;
+    static constexpr NextWithShift kStandaloneMarker{UINT64_MAX};
 
     // A marker for head_next_with_shift indicating the head is not yet part
     // of the usable table, or for chain_next_with_shift indicating that the
     // entry is not present or is not yet part of a chain (must not be
     // "shareable" state).
-    static constexpr uint64_t kUnusedMarker = 0;
+    static constexpr NextWithShift kUnusedMarker{0};
 
     // See above. The head pointer is logically independent of the rest of
     // the entry, including the chain next pointer.
-    AcqRelAtomic<uint64_t> head_next_with_shift{kUnusedMarker};
-    AcqRelAtomic<uint64_t> chain_next_with_shift{kUnusedMarker};
+    BitFieldsAtomic<NextWithShift> head_next_with_shift{kUnusedMarker};
+    BitFieldsAtomic<NextWithShift> chain_next_with_shift{kUnusedMarker};
 
     // For supporting CreateStandalone and some fallback cases.
     inline bool IsStandalone() const {
@@ -841,7 +925,7 @@ class AutoHyperClockTable : public BaseClockTable {
     size_t min_avg_value_size;
   };
 
-  AutoHyperClockTable(size_t capacity,
+  AutoHyperClockTable(size_t capacity, bool strict_capacity_limit,
                       CacheMetadataChargePolicy metadata_charge_policy,
                       MemoryAllocator* allocator,
                       const Cache::EvictionCallback* eviction_callback,
@@ -862,14 +946,13 @@ class AutoHyperClockTable : public BaseClockTable {
   bool GrowIfNeeded(size_t new_occupancy, InsertState& state);
 
   HandleImpl* DoInsert(const ClockHandleBasicData& proto,
-                       uint64_t initial_countdown, bool take_ref,
+                       uint32_t initial_countdown, bool take_ref,
                        InsertState& state);
 
   // Runs the clock eviction algorithm trying to reclaim at least
   // requested_charge. Returns how much is evicted, which could be less
   // if it appears impossible to evict the requested amount without blocking.
-  void Evict(size_t requested_charge, InsertState& state, EvictionData* data,
-             uint32_t eviction_effort_cap);
+  void Evict(size_t requested_charge, InsertState& state, EvictionData* data);
 
   HandleImpl* Lookup(const UniqueId64x2& hashed_key);
 
@@ -891,7 +974,7 @@ class AutoHyperClockTable : public BaseClockTable {
   }
 
   // Release N references
-  void TEST_ReleaseN(HandleImpl* handle, size_t n);
+  void TEST_ReleaseN(HandleImpl* handle, uint32_t n);
 #endif
 
   // Maximum ratio of number of occupied slots to number of usable slots. The
@@ -973,7 +1056,7 @@ class AutoHyperClockTable : public BaseClockTable {
   // To maximize parallelization of Grow() operations, this field is only
   // updated opportunistically after Grow() operations and in DoInsert() where
   // it is found to be out-of-date. See CatchUpLengthInfoNoWait().
-  AcqRelAtomic<uint64_t> length_info_;
+  Atomic<uint64_t> length_info_;
 
   // An already-computed version of the usable length times the max load
   // factor. Could be slightly out of date but GrowIfNeeded()/Grow() handle
@@ -1096,21 +1179,12 @@ class ALIGN_AS(CACHE_LINE_SIZE) ClockCacheShard final : public CacheShardBase {
     return table_.TEST_MutableOccupancyLimit();
   }
   // Acquire/release N references
-  void TEST_RefN(HandleImpl* handle, size_t n);
-  void TEST_ReleaseN(HandleImpl* handle, size_t n);
+  void TEST_RefN(HandleImpl* handle, uint32_t n);
+  void TEST_ReleaseN(HandleImpl* handle, uint32_t n);
 #endif
 
  private:  // data
   Table table_;
-
-  // Maximum total charge of all elements stored in the table.
-  // (Relaxed: eventual consistency/update is OK)
-  RelaxedAtomic<size_t> capacity_;
-
-  // Encodes eviction_effort_cap (bottom 31 bits) and strict_capacity_limit
-  // (top bit). See HyperClockCacheOptions::eviction_effort_cap etc.
-  // (Relaxed: eventual consistency/update is OK)
-  RelaxedAtomic<uint32_t> eec_and_scl_;
 };  // class ClockCacheShard
 
 template <class Table>

cache/compressed_secondary_cache.cc

@@ -16,6 +16,31 @@
 #include "util/string_util.h"
 
 namespace ROCKSDB_NAMESPACE {
+namespace {
+// Format of values in CompressedSecondaryCache:
+// If enable_custom_split_merge:
+//  * A chain of CacheValueChunk representing the sequence of bytes for a tagged
+//    value. The overall length of the tagged value is determined by the chain
+//    of CacheValueChunks.
+// If !enable_custom_split_merge:
+//  * A LengthPrefixedSlice (starts with varint64 size) of a tagged value.
+//
+// A tagged value has a 2-byte header before the "saved" or compressed block
+// data:
+//  * 1 byte for "source" CacheTier indicating which tier is responsible for
+//    compression/decompression.
+//  * 1 byte for compression type which is generated/used by
+//    CompressedSecondaryCache iff source == CacheTier::kVolatileCompressedTier
+//    (original entry passed in was uncompressed). Otherwise, the compression
+//    type is preserved from the entry passed in.
+constexpr uint32_t kTagSize = 2;
+
+// Size of tag + varint size prefix when applicable
+uint32_t GetHeaderSize(size_t data_size, bool enable_split_merge) {
+  return (enable_split_merge ? 0 : VarintLength(kTagSize + data_size)) +
+         kTagSize;
+}
+}  // namespace
 
 CompressedSecondaryCache::CompressedSecondaryCache(
     const CompressedSecondaryCacheOptions& opts)
@@ -24,7 +49,13 @@ CompressedSecondaryCache::CompressedSecondaryCache(
       cache_res_mgr_(std::make_shared<ConcurrentCacheReservationManager>(
           std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
               cache_))),
-      disable_cache_(opts.capacity == 0) {}
+      disable_cache_(opts.capacity == 0) {
+  auto mgr = GetBuiltinV2CompressionManager();
+  compressor_ = mgr->GetCompressor(cache_options_.compression_opts,
+                                   cache_options_.compression_type);
+  decompressor_ =
+      mgr->GetDecompressorOptimizeFor(cache_options_.compression_type);
+}
 
 CompressedSecondaryCache::~CompressedSecondaryCache() = default;
 
@@ -33,13 +64,9 @@ std::unique_ptr<SecondaryCacheResultHandle> CompressedSecondaryCache::Lookup(
     Cache::CreateContext* create_context, bool /*wait*/, bool advise_erase,
     Statistics* stats, bool& kept_in_sec_cache) {
   assert(helper);
-  // This is a minor optimization. Its ok to skip it in TSAN in order to
-  // avoid a false positive.
-#ifndef __SANITIZE_THREAD__
-  if (disable_cache_) {
+  if (disable_cache_.LoadRelaxed()) {
     return nullptr;
   }
-#endif
 
   std::unique_ptr<SecondaryCacheResultHandle> handle;
   kept_in_sec_cache = false;
@@ -55,75 +82,58 @@ std::unique_ptr<SecondaryCacheResultHandle> CompressedSecondaryCache::Lookup(
     return nullptr;
   }
 
-  CacheAllocationPtr* ptr{nullptr};
-  CacheAllocationPtr merged_value;
-  size_t handle_value_charge{0};
-  const char* data_ptr = nullptr;
-  CacheTier source = CacheTier::kVolatileCompressedTier;
-  CompressionType type = cache_options_.compression_type;
+  std::string merged_value;
+  Slice tagged_data;
   if (cache_options_.enable_custom_split_merge) {
     CacheValueChunk* value_chunk_ptr =
-        reinterpret_cast<CacheValueChunk*>(handle_value);
-    merged_value = MergeChunksIntoValue(value_chunk_ptr, handle_value_charge);
-    ptr = &merged_value;
-    data_ptr = ptr->get();
+        static_cast<CacheValueChunk*>(handle_value);
+    merged_value = MergeChunksIntoValue(value_chunk_ptr);
+    tagged_data = Slice(merged_value);
   } else {
-    uint32_t type_32 = static_cast<uint32_t>(type);
-    uint32_t source_32 = static_cast<uint32_t>(source);
-    ptr = reinterpret_cast<CacheAllocationPtr*>(handle_value);
-    handle_value_charge = cache_->GetCharge(lru_handle);
-    data_ptr = ptr->get();
-    data_ptr = GetVarint32Ptr(data_ptr, data_ptr + 1,
-                              static_cast<uint32_t*>(&type_32));
-    type = static_cast<CompressionType>(type_32);
-    data_ptr = GetVarint32Ptr(data_ptr, data_ptr + 1,
-                              static_cast<uint32_t*>(&source_32));
-    source = static_cast<CacheTier>(source_32);
-    uint64_t data_size = 0;
-    data_ptr = GetVarint64Ptr(data_ptr, ptr->get() + handle_value_charge,
-                              static_cast<uint64_t*>(&data_size));
-    assert(handle_value_charge > data_size);
-    handle_value_charge = data_size;
+    tagged_data = GetLengthPrefixedSlice(static_cast<char*>(handle_value));
   }
-  MemoryAllocator* allocator = cache_options_.memory_allocator.get();
 
-  Status s;
-  Cache::ObjectPtr value{nullptr};
-  size_t charge{0};
+  auto source = lossless_cast<CacheTier>(tagged_data[0]);
+  auto type = lossless_cast<CompressionType>(tagged_data[1]);
+
+  std::unique_ptr<char[]> uncompressed;
+  Slice saved(tagged_data.data() + kTagSize, tagged_data.size() - kTagSize);
   if (source == CacheTier::kVolatileCompressedTier) {
-    if (cache_options_.compression_type == kNoCompression ||
-        cache_options_.do_not_compress_roles.Contains(helper->role)) {
-      s = helper->create_cb(Slice(data_ptr, handle_value_charge),
-                            kNoCompression, CacheTier::kVolatileTier,
-                            create_context, allocator, &value, &charge);
-    } else {
-      UncompressionContext uncompression_context(
-          cache_options_.compression_type);
-      UncompressionInfo uncompression_info(uncompression_context,
-                                           UncompressionDict::GetEmptyDict(),
-                                           cache_options_.compression_type);
-
-      size_t uncompressed_size{0};
-      CacheAllocationPtr uncompressed =
-          UncompressData(uncompression_info, (char*)data_ptr,
-                         handle_value_charge, &uncompressed_size,
-                         cache_options_.compress_format_version, allocator);
-
-      if (!uncompressed) {
+    if (type != kNoCompression) {
+      // TODO: can we do something to avoid yet another allocation?
+      Decompressor::Args args;
+      args.compressed_data = saved;
+      args.compression_type = type;
+      Status s = decompressor_->ExtractUncompressedSize(args);
+      assert(s.ok());  // in-memory data
+      if (s.ok()) {
+        uncompressed = std::make_unique<char[]>(args.uncompressed_size);
+        s = decompressor_->DecompressBlock(args, uncompressed.get());
+        assert(s.ok());  // in-memory data
+      }
+      if (!s.ok()) {
         cache_->Release(lru_handle, /*erase_if_last_ref=*/true);
         return nullptr;
       }
-      s = helper->create_cb(Slice(uncompressed.get(), uncompressed_size),
-                            kNoCompression, CacheTier::kVolatileTier,
-                            create_context, allocator, &value, &charge);
+      saved = Slice(uncompressed.get(), args.uncompressed_size);
+      type = kNoCompression;
+      // Free temporary compressed data as early as we can. This could matter
+      // for unusually large blocks because we also have
+      // * Another compressed copy above (from lru_cache).
+      // * The uncompressed copy in `uncompressed`.
+      // * Another uncompressed copy in `result_value` below.
+      // Let's try to max out at 3 copies instead of 4.
+      merged_value = std::string();
     }
-  } else {
-    // The item was not compressed by us. Let the helper create_cb
-    // uncompress it
-    s = helper->create_cb(Slice(data_ptr, handle_value_charge), type, source,
-                          create_context, allocator, &value, &charge);
+    // Reduced as if it came from primary cache
+    source = CacheTier::kVolatileTier;
   }
 
+  Cache::ObjectPtr result_value = nullptr;
+  size_t result_charge = 0;
+  Status s = helper->create_cb(saved, type, source, create_context,
+                               cache_options_.memory_allocator.get(),
+                               &result_value, &result_charge);
   if (!s.ok()) {
     cache_->Release(lru_handle, /*erase_if_last_ref=*/true);
     return nullptr;
@@ -141,7 +151,8 @@ std::unique_ptr<SecondaryCacheResultHandle> CompressedSecondaryCache::Lookup(
     kept_in_sec_cache = true;
     cache_->Release(lru_handle, /*erase_if_last_ref=*/false);
   }
-  handle.reset(new CompressedSecondaryCacheResultHandle(value, charge));
+  handle.reset(
+      new CompressedSecondaryCacheResultHandle(result_value, result_charge));
   RecordTick(stats, COMPRESSED_SECONDARY_CACHE_HITS);
   return handle;
 }
@@ -164,88 +175,111 @@ bool CompressedSecondaryCache::MaybeInsertDummy(const Slice& key) {
 
 Status CompressedSecondaryCache::InsertInternal(
     const Slice& key, Cache::ObjectPtr value,
-    const Cache::CacheItemHelper* helper, CompressionType type,
+    const Cache::CacheItemHelper* helper, CompressionType from_type,
     CacheTier source) {
-  if (source != CacheTier::kVolatileCompressedTier &&
-      cache_options_.enable_custom_split_merge) {
-    // We don't support custom split/merge for the tiered case
-    return Status::OK();
-  }
+  bool enable_split_merge = cache_options_.enable_custom_split_merge;
+  const Cache::CacheItemHelper* internal_helper = GetHelper(enable_split_merge);
 
-  auto internal_helper = GetHelper(cache_options_.enable_custom_split_merge);
-  char header[20];
-  char* payload = header;
-  payload = EncodeVarint32(payload, static_cast<uint32_t>(type));
-  payload = EncodeVarint32(payload, static_cast<uint32_t>(source));
-  size_t data_size = (*helper->size_cb)(value);
-  char* data_size_ptr = payload;
-  payload = EncodeVarint64(payload, data_size);
+  // TODO: variant of size_cb that also returns a pointer to the data if
+  // already available. Saves an allocation if we keep the compressed version.
+  const size_t data_size_original = (*helper->size_cb)(value);
 
-  size_t header_size = payload - header;
-  size_t total_size = data_size + header_size;
-  CacheAllocationPtr ptr =
-      AllocateBlock(total_size, cache_options_.memory_allocator.get());
-  char* data_ptr = ptr.get() + header_size;
+  // Allocate enough memory for header/tag + original data because (a) we might
+  // not be attempting compression at all, and (b) we might keep the original if
+  // compression is insufficient. But we don't need the length prefix with
+  // enable_split_merge. TODO: be smarter with CacheValueChunk to save an
+  // allocation in the enable_split_merge case.
+  size_t header_size = GetHeaderSize(data_size_original, enable_split_merge);
+  CacheAllocationPtr allocation = AllocateBlock(
+      header_size + data_size_original, cache_options_.memory_allocator.get());
+  char* data_ptr = allocation.get() + header_size;
+  Slice tagged_data(data_ptr - kTagSize, data_size_original + kTagSize);
+  assert(tagged_data.data() >= allocation.get());
 
-  Status s = (*helper->saveto_cb)(value, 0, data_size, data_ptr);
+  Status s = (*helper->saveto_cb)(value, 0, data_size_original, data_ptr);
   if (!s.ok()) {
     return s;
   }
-  Slice val(data_ptr, data_size);
 
-  std::string compressed_val;
-  if (cache_options_.compression_type != kNoCompression &&
-      type == kNoCompression &&
+  std::unique_ptr<char[]> tagged_compressed_data;
+  CompressionType to_type = kNoCompression;
+  if (compressor_ && from_type == kNoCompression &&
       !cache_options_.do_not_compress_roles.Contains(helper->role)) {
-    PERF_COUNTER_ADD(compressed_sec_cache_uncompressed_bytes, data_size);
-    CompressionContext compression_context(cache_options_.compression_type,
-                                           cache_options_.compression_opts);
-    uint64_t sample_for_compression{0};
-    CompressionInfo compression_info(
-        cache_options_.compression_opts, compression_context,
-        CompressionDict::GetEmptyDict(), cache_options_.compression_type,
-        sample_for_compression);
+    assert(source == CacheTier::kVolatileCompressedTier);
 
-    bool success =
-        CompressData(val, compression_info,
-                     cache_options_.compress_format_version, &compressed_val);
-
-    if (!success) {
-      return Status::Corruption("Error compressing value.");
+    // TODO: consider malloc sizes for max acceptable compressed size
+    // Or maybe max_compressed_bytes_per_kb
+    size_t data_size_compressed = data_size_original - 1;
+    tagged_compressed_data =
+        std::make_unique<char[]>(data_size_compressed + kTagSize);
+    s = compressor_->CompressBlock(Slice(data_ptr, data_size_original),
+                                   tagged_compressed_data.get() + kTagSize,
+                                   &data_size_compressed, &to_type,
+                                   nullptr /*working_area*/);
+    if (!s.ok()) {
+      return s;
     }
-
-    val = Slice(compressed_val);
-    data_size = compressed_val.size();
-    payload = EncodeVarint64(data_size_ptr, data_size);
-    header_size = payload - header;
-    total_size = header_size + data_size;
-    PERF_COUNTER_ADD(compressed_sec_cache_compressed_bytes, data_size);
-
-    if (!cache_options_.enable_custom_split_merge) {
-      ptr = AllocateBlock(total_size, cache_options_.memory_allocator.get());
-      data_ptr = ptr.get() + header_size;
-      memcpy(data_ptr, compressed_val.data(), data_size);
+    PERF_COUNTER_ADD(compressed_sec_cache_uncompressed_bytes,
+                     data_size_original);
+    if (to_type == kNoCompression) {
+      // Compression rejected or otherwise aborted/failed
+      to_type = kNoCompression;
+      tagged_compressed_data.reset();
+      // TODO: consider separate counters for rejected compressions
+      PERF_COUNTER_ADD(compressed_sec_cache_compressed_bytes,
+                       data_size_original);
+    } else {
+      PERF_COUNTER_ADD(compressed_sec_cache_compressed_bytes,
+                       data_size_compressed);
+      if (enable_split_merge) {
+        // Only need tagged_data for copying into CacheValueChunks.
+        tagged_data = Slice(tagged_compressed_data.get(),
+                            data_size_compressed + kTagSize);
+        allocation.reset();
+      } else {
+        // Replace allocation with compressed version, copied from string
+        header_size = GetHeaderSize(data_size_compressed, enable_split_merge);
+        allocation = AllocateBlock(header_size + data_size_compressed,
+                                   cache_options_.memory_allocator.get());
+        data_ptr = allocation.get() + header_size;
+        // Ignore unpopulated tag on tagged_compressed_data; will only be
+        // populated on the new allocation.
+        std::memcpy(data_ptr, tagged_compressed_data.get() + kTagSize,
+                    data_size_compressed);
+        tagged_data =
+            Slice(data_ptr - kTagSize, data_size_compressed + kTagSize);
+        assert(tagged_data.data() >= allocation.get());
+      }
     }
   }
 
   PERF_COUNTER_ADD(compressed_sec_cache_insert_real_count, 1);
-  if (cache_options_.enable_custom_split_merge) {
+
+  // Save the tag fields
+  const_cast<char*>(tagged_data.data())[0] = lossless_cast<char>(source);
+  const_cast<char*>(tagged_data.data())[1] = lossless_cast<char>(
+      source == CacheTier::kVolatileCompressedTier ? to_type : from_type);
+
+  if (enable_split_merge) {
     size_t split_charge{0};
-    CacheValueChunk* value_chunks_head = SplitValueIntoChunks(
-        val, cache_options_.compression_type, split_charge);
-    return cache_->Insert(key, value_chunks_head, internal_helper,
-                          split_charge);
+    CacheValueChunk* value_chunks_head =
+        SplitValueIntoChunks(tagged_data, split_charge);
+    s = cache_->Insert(key, value_chunks_head, internal_helper, split_charge);
+    assert(s.ok());  // LRUCache::Insert() with handle==nullptr always OK
   } else {
+    // Save the size prefix
+    char* ptr = allocation.get();
+    ptr = EncodeVarint64(ptr, tagged_data.size());
+    assert(ptr == tagged_data.data());
 #ifdef ROCKSDB_MALLOC_USABLE_SIZE
-    size_t charge = malloc_usable_size(ptr.get());
+    size_t charge = malloc_usable_size(allocation.get());
 #else
-    size_t charge = total_size;
+    size_t charge = tagged_data.size();
 #endif
-    std::memcpy(ptr.get(), header, header_size);
-    CacheAllocationPtr* buf = new CacheAllocationPtr(std::move(ptr));
-    charge += sizeof(CacheAllocationPtr);
-    return cache_->Insert(key, buf, internal_helper, charge);
+    s = cache_->Insert(key, allocation.release(), internal_helper, charge);
+    assert(s.ok());  // LRUCache::Insert() with handle==nullptr always OK
   }
+  return Status::OK();
 }
 
 Status CompressedSecondaryCache::Insert(const Slice& key,
@@ -267,7 +301,17 @@ Status CompressedSecondaryCache::Insert(const Slice& key,
 Status CompressedSecondaryCache::InsertSaved(
     const Slice& key, const Slice& saved, CompressionType type = kNoCompression,
     CacheTier source = CacheTier::kVolatileTier) {
+  if (source == CacheTier::kVolatileCompressedTier) {
+    // Unexpected, would violate InsertInternal preconditions
+    assert(source != CacheTier::kVolatileCompressedTier);
+    return Status::OK();
+  }
   if (type == kNoCompression) {
+    // Not currently supported (why?)
+    return Status::OK();
+  }
+  if (cache_options_.enable_custom_split_merge) {
+    // We don't support custom split/merge for the tiered case (why?)
     return Status::OK();
   }
 
@@ -287,7 +331,7 @@ Status CompressedSecondaryCache::SetCapacity(size_t capacity) {
   MutexLock l(&capacity_mutex_);
   cache_options_.capacity = capacity;
   cache_->SetCapacity(capacity);
-  disable_cache_ = capacity == 0;
+  disable_cache_.StoreRelaxed(capacity == 0);
   return Status::OK();
 }
 
@@ -311,15 +355,17 @@ std::string CompressedSecondaryCache::GetPrintableOptions() const {
                const_cast<CompressionOptions&>(cache_options_.compression_opts))
                .c_str());
   ret.append(buffer);
-  snprintf(buffer, kBufferSize, "    compress_format_version : %d\n",
-           cache_options_.compress_format_version);
-  ret.append(buffer);
   return ret;
 }
 
+// FIXME: this could use a lot of attention, including:
+// * Use allocator
+// * We shouldn't be worse than non-split; be more pro-actively aware of
+// internal fragmentation
+// * Consider a unified object/chunk structure that may or may not split
+// * Optimize size overhead of chunks
 CompressedSecondaryCache::CacheValueChunk*
 CompressedSecondaryCache::SplitValueIntoChunks(const Slice& value,
-                                               CompressionType compression_type,
                                                size_t& charge) {
   assert(!value.empty());
   const char* src_ptr = value.data();
@@ -340,15 +386,14 @@ CompressedSecondaryCache::SplitValueIntoChunks(const Slice& value,
     // size, or there is no compression.
     if (upper == malloc_bin_sizes_.begin() ||
         upper == malloc_bin_sizes_.end() ||
-        *upper - predicted_chunk_size < malloc_bin_sizes_.front() ||
-        compression_type == kNoCompression) {
+        *upper - predicted_chunk_size < malloc_bin_sizes_.front()) {
       tmp_size = predicted_chunk_size;
     } else {
       tmp_size = *(--upper);
     }
 
     CacheValueChunk* new_chunk =
-        reinterpret_cast<CacheValueChunk*>(new char[tmp_size]);
+        static_cast<CacheValueChunk*>(static_cast<void*>(new char[tmp_size]));
     current_chunk->next = new_chunk;
     current_chunk = current_chunk->next;
     actual_chunk_size = tmp_size - sizeof(CacheValueChunk) + 1;
@@ -363,28 +408,24 @@ CompressedSecondaryCache::SplitValueIntoChunks(const Slice& value,
   return dummy_head.next;
 }
 
-CacheAllocationPtr CompressedSecondaryCache::MergeChunksIntoValue(
-    const void* chunks_head, size_t& charge) {
-  const CacheValueChunk* head =
-      reinterpret_cast<const CacheValueChunk*>(chunks_head);
+std::string CompressedSecondaryCache::MergeChunksIntoValue(
+    const CacheValueChunk* head) {
   const CacheValueChunk* current_chunk = head;
-  charge = 0;
+  size_t total_size = 0;
   while (current_chunk != nullptr) {
-    charge += current_chunk->size;
+    total_size += current_chunk->size;
     current_chunk = current_chunk->next;
   }
 
-  CacheAllocationPtr ptr =
-      AllocateBlock(charge, cache_options_.memory_allocator.get());
+  std::string result;
+  result.reserve(total_size);
   current_chunk = head;
-  size_t pos{0};
   while (current_chunk != nullptr) {
-    memcpy(ptr.get() + pos, current_chunk->data, current_chunk->size);
-    pos += current_chunk->size;
+    result.append(current_chunk->data, current_chunk->size);
     current_chunk = current_chunk->next;
   }
-
-  return ptr;
+  assert(result.size() == total_size);
+  return result;
 }
 
 const Cache::CacheItemHelper* CompressedSecondaryCache::GetHelper(
@@ -398,16 +439,16 @@ const Cache::CacheItemHelper* CompressedSecondaryCache::GetHelper(
             CacheValueChunk* tmp_chunk = chunks_head;
             chunks_head = chunks_head->next;
             tmp_chunk->Free();
-            obj = nullptr;
           }
         }};
     return &kHelper;
   } else {
     static const Cache::CacheItemHelper kHelper{
         CacheEntryRole::kMisc,
-        [](Cache::ObjectPtr obj, MemoryAllocator* /*alloc*/) {
-          delete static_cast<CacheAllocationPtr*>(obj);
-          obj = nullptr;
+        [](Cache::ObjectPtr obj, MemoryAllocator* alloc) {
+          if (obj != nullptr) {
+            CacheAllocationDeleter{alloc}(static_cast<char*>(obj));
+          }
         }};
     return &kHelper;
   }
@@ -418,12 +459,7 @@ size_t CompressedSecondaryCache::TEST_GetCharge(const Slice& key) {
   if (lru_handle == nullptr) {
     return 0;
   }
-
   size_t charge = cache_->GetCharge(lru_handle);
-  if (cache_->Value(lru_handle) != nullptr &&
-      !cache_options_.enable_custom_split_merge) {
-    charge -= 10;
-  }
   cache_->Release(lru_handle, /*erase_if_last_ref=*/false);
   return charge;
 }

cache/compressed_secondary_cache.h

@@ -10,13 +10,12 @@
 #include <memory>
 
 #include "cache/cache_reservation_manager.h"
-#include "cache/lru_cache.h"
 #include "memory/memory_allocator_impl.h"
+#include "rocksdb/advanced_compression.h"
 #include "rocksdb/secondary_cache.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/status.h"
-#include "util/compression.h"
-#include "util/mutexlock.h"
+#include "util/atomic.h"
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -124,14 +123,9 @@ class CompressedSecondaryCache : public SecondaryCache {
   // Split value into chunks to better fit into jemalloc bins. The chunks
   // are stored in CacheValueChunk and extra charge is needed for each chunk,
   // so the cache charge is recalculated here.
-  CacheValueChunk* SplitValueIntoChunks(const Slice& value,
-                                        CompressionType compression_type,
-                                        size_t& charge);
+  CacheValueChunk* SplitValueIntoChunks(const Slice& value, size_t& charge);
 
-  // After merging chunks, the extra charge for each chunk is removed, so
-  // the charge is recalculated.
-  CacheAllocationPtr MergeChunksIntoValue(const void* chunks_head,
-                                          size_t& charge);
+  std::string MergeChunksIntoValue(const CacheValueChunk* head);
 
   bool MaybeInsertDummy(const Slice& key);
 
@@ -145,9 +139,11 @@ class CompressedSecondaryCache : public SecondaryCache {
   const Cache::CacheItemHelper* GetHelper(bool enable_custom_split_merge) const;
   std::shared_ptr<Cache> cache_;
   CompressedSecondaryCacheOptions cache_options_;
+  std::unique_ptr<Compressor> compressor_;
+  std::shared_ptr<Decompressor> decompressor_;
   mutable port::Mutex capacity_mutex_;
   std::shared_ptr<ConcurrentCacheReservationManager> cache_res_mgr_;
-  bool disable_cache_;
+  RelaxedAtomic<bool> disable_cache_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

cache/compressed_secondary_cache_test.cc

@@ -24,6 +24,14 @@ namespace ROCKSDB_NAMESPACE {
 using secondary_cache_test_util::GetTestingCacheTypes;
 using secondary_cache_test_util::WithCacheType;
 
+// Read and reset a statistic
+template <typename T>
+T Pop(T& var) {
+  T ret = var;
+  var = T();
+  return ret;
+}
+
 // 16 bytes for HCC compatibility
 const std::string key0 = "____    ____key0";
 const std::string key1 = "____    ____key1";
@@ -51,7 +59,7 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
 
     Random rnd(301);
     // Insert and Lookup the item k1 for the first time.
-    std::string str1(rnd.RandomString(1000));
+    std::string str1 = test::CompressibleString(&rnd, 0.5, 1000);
     TestItem item1(str1.data(), str1.length());
     // A dummy handle is inserted if the item is inserted for the first time.
     ASSERT_OK(sec_cache->Insert(key1, &item1, GetHelper(), false));
@@ -68,7 +76,14 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_OK(sec_cache->Insert(key1, &item1, GetHelper(), false));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 1);
 
-    ASSERT_GT(comp_sec_cache->TEST_GetCharge(key1), 1000);
+    if (sec_cache_is_compressed) {
+      ASSERT_GT(comp_sec_cache->TEST_GetCharge(key1), str1.length() / 4);
+      ASSERT_LT(comp_sec_cache->TEST_GetCharge(key1), str1.length() * 3 / 4);
+    } else {
+      ASSERT_GE(comp_sec_cache->TEST_GetCharge(key1), str1.length());
+      // NOTE: split-merge is worse (1048 vs. 1024)
+      ASSERT_LE(comp_sec_cache->TEST_GetCharge(key1), 1048U);
+    }
 
     std::unique_ptr<SecondaryCacheResultHandle> handle1_2 =
         sec_cache->Lookup(key1, GetHelper(), this, true, /*advise_erase=*/true,
@@ -76,10 +91,13 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_NE(handle1_2, nullptr);
     ASSERT_FALSE(kept_in_sec_cache);
     if (sec_cache_is_compressed) {
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
-                1000);
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
-                1007);
+      ASSERT_EQ(
+          Pop(get_perf_context()->compressed_sec_cache_uncompressed_bytes),
+          str1.length());
+      ASSERT_LT(get_perf_context()->compressed_sec_cache_compressed_bytes,
+                str1.length() * 3 / 4);
+      ASSERT_GT(Pop(get_perf_context()->compressed_sec_cache_compressed_bytes),
+                str1.length() / 4);
     } else {
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
@@ -97,7 +115,7 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_EQ(handle1_3, nullptr);
 
     // Insert and Lookup the item k2.
-    std::string str2(rnd.RandomString(1000));
+    std::string str2 = test::CompressibleString(&rnd, 0.5, 1017);
     TestItem item2(str2.data(), str2.length());
     ASSERT_OK(sec_cache->Insert(key2, &item2, GetHelper(), false));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 2);
@@ -109,10 +127,13 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_OK(sec_cache->Insert(key2, &item2, GetHelper(), false));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 2);
     if (sec_cache_is_compressed) {
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
-                2000);
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
-                2014);
+      ASSERT_EQ(
+          Pop(get_perf_context()->compressed_sec_cache_uncompressed_bytes),
+          str2.length());
+      ASSERT_LT(get_perf_context()->compressed_sec_cache_compressed_bytes,
+                str2.length() * 3 / 4);
+      ASSERT_GT(Pop(get_perf_context()->compressed_sec_cache_compressed_bytes),
+                str2.length() / 4);
     } else {
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
@@ -126,9 +147,48 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_NE(val2, nullptr);
     ASSERT_EQ(memcmp(val2->Buf(), item2.Buf(), item2.Size()), 0);
 
+    // Release handles
     std::vector<SecondaryCacheResultHandle*> handles = {handle1_2.get(),
                                                         handle2_2.get()};
     sec_cache->WaitAll(handles);
+    handle1_2.reset();
+    handle2_2.reset();
+
+    // Insert and Lookup a non-compressible item k3.
+    std::string str3 = rnd.RandomBinaryString(480);
+    TestItem item3(str3.data(), str3.length());
+    ASSERT_OK(sec_cache->Insert(key3, &item3, GetHelper(), false));
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 3);
+    std::unique_ptr<SecondaryCacheResultHandle> handle3_1 =
+        sec_cache->Lookup(key3, GetHelper(), this, true, /*advise_erase=*/false,
+                          /*stats=*/nullptr, kept_in_sec_cache);
+    ASSERT_EQ(handle3_1, nullptr);
+
+    ASSERT_OK(sec_cache->Insert(key3, &item3, GetHelper(), false));
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 3);
+    if (sec_cache_is_compressed) {
+      // TODO: consider a compression rejected stat?
+      ASSERT_EQ(
+          Pop(get_perf_context()->compressed_sec_cache_uncompressed_bytes),
+          str3.length());
+      ASSERT_EQ(Pop(get_perf_context()->compressed_sec_cache_compressed_bytes),
+                str3.length());
+    } else {
+      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
+      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
+    }
+
+    std::unique_ptr<SecondaryCacheResultHandle> handle3_2 =
+        sec_cache->Lookup(key3, GetHelper(), this, true, /*advise_erase=*/false,
+                          /*stats=*/nullptr, kept_in_sec_cache);
+    ASSERT_NE(handle3_2, nullptr);
+    std::unique_ptr<TestItem> val3 =
+        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle3_2->Value()));
+    ASSERT_NE(val3, nullptr);
+    ASSERT_EQ(memcmp(val3->Buf(), item3.Buf(), item3.Size()), 0);
+
+    EXPECT_GE(comp_sec_cache->TEST_GetCharge(key3), str3.length());
+    EXPECT_LE(comp_sec_cache->TEST_GetCharge(key3), 512);
 
     sec_cache.reset();
   }
@@ -178,8 +238,9 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
       secondary_cache_opts.compression_type = CompressionType::kNoCompression;
     }
 
-    secondary_cache_opts.capacity = 1100;
+    secondary_cache_opts.capacity = 1400;
     secondary_cache_opts.num_shard_bits = 0;
+    secondary_cache_opts.strict_capacity_limit = true;
     std::shared_ptr<SecondaryCache> sec_cache =
         NewCompressedSecondaryCache(secondary_cache_opts);
 
@@ -193,7 +254,7 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_OK(sec_cache->Insert(key1, &item1, GetHelper(), false));
 
     // Insert and Lookup the second item.
-    std::string str2(rnd.RandomString(200));
+    std::string str2(rnd.RandomString(500));
     TestItem item2(str2.data(), str2.length());
     // Insert a dummy handle, k1 is not evicted.
     ASSERT_OK(sec_cache->Insert(key2, &item2, GetHelper(), false));
@@ -201,16 +262,23 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     std::unique_ptr<SecondaryCacheResultHandle> handle1 =
         sec_cache->Lookup(key1, GetHelper(), this, true, /*advise_erase=*/false,
                           /*stats=*/nullptr, kept_in_sec_cache);
-    ASSERT_EQ(handle1, nullptr);
+    ASSERT_NE(handle1, nullptr);
+    std::unique_ptr<TestItem> val1{static_cast<TestItem*>(handle1->Value())};
+    ASSERT_NE(val1, nullptr);
+    ASSERT_EQ(val1->ToString(), str1);
+    handle1.reset();
 
     // Insert k2 and k1 is evicted.
     ASSERT_OK(sec_cache->Insert(key2, &item2, GetHelper(), false));
+    handle1 =
+        sec_cache->Lookup(key1, GetHelper(), this, true, /*advise_erase=*/false,
+                          /*stats=*/nullptr, kept_in_sec_cache);
+    ASSERT_EQ(handle1, nullptr);
     std::unique_ptr<SecondaryCacheResultHandle> handle2 =
         sec_cache->Lookup(key2, GetHelper(), this, true, /*advise_erase=*/false,
                           /*stats=*/nullptr, kept_in_sec_cache);
     ASSERT_NE(handle2, nullptr);
-    std::unique_ptr<TestItem> val2 =
-        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle2->Value()));
+    std::unique_ptr<TestItem> val2{static_cast<TestItem*>(handle2->Value())};
     ASSERT_NE(val2, nullptr);
     ASSERT_EQ(memcmp(val2->Buf(), item2.Buf(), item2.Size()), 0);
 
@@ -232,7 +300,7 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     // Save Fails.
     std::string str3 = rnd.RandomString(10);
     TestItem item3(str3.data(), str3.length());
-    // The Status is OK because a dummy handle is inserted.
+    // The first Status is OK because a dummy handle is inserted.
     ASSERT_OK(sec_cache->Insert(key3, &item3, GetHelperFail(), false));
     ASSERT_NOK(sec_cache->Insert(key3, &item3, GetHelperFail(), false));
 
@@ -265,11 +333,11 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
 
     get_perf_context()->Reset();
     Random rnd(301);
-    std::string str1 = rnd.RandomString(1001);
+    std::string str1 = test::CompressibleString(&rnd, 0.5, 1001);
     auto item1_1 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert(key1, item1_1, GetHelper(), str1.length()));
 
-    std::string str2 = rnd.RandomString(1012);
+    std::string str2 = test::CompressibleString(&rnd, 0.5, 1012);
     auto item2_1 = new TestItem(str2.data(), str2.length());
     // After this Insert, primary cache contains k2 and secondary cache contains
     // k1's dummy item.
@@ -278,7 +346,7 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
 
-    std::string str3 = rnd.RandomString(1024);
+    std::string str3 = test::CompressibleString(&rnd, 0.5, 1024);
     auto item3_1 = new TestItem(str3.data(), str3.length());
     // After this Insert, primary cache contains k3 and secondary cache contains
     // k1's dummy item and k2's dummy item.
@@ -297,10 +365,13 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_OK(cache->Insert(key2, item2_2, GetHelper(), str2.length()));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 1);
     if (sec_cache_is_compressed) {
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
+      ASSERT_EQ(
+          Pop(get_perf_context()->compressed_sec_cache_uncompressed_bytes),
+          str1.length());
+      ASSERT_LT(get_perf_context()->compressed_sec_cache_compressed_bytes,
                 str1.length());
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
-                1008);
+      ASSERT_GT(Pop(get_perf_context()->compressed_sec_cache_compressed_bytes),
+                str1.length() / 10);
     } else {
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
@@ -312,10 +383,13 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     ASSERT_OK(cache->Insert(key3, item3_2, GetHelper(), str3.length()));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 2);
     if (sec_cache_is_compressed) {
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
-                str1.length() + str2.length());
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
-                2027);
+      ASSERT_EQ(
+          Pop(get_perf_context()->compressed_sec_cache_uncompressed_bytes),
+          str2.length());
+      ASSERT_LT(get_perf_context()->compressed_sec_cache_compressed_bytes,
+                str2.length());
+      ASSERT_GT(Pop(get_perf_context()->compressed_sec_cache_compressed_bytes),
+                str2.length() / 10);
     } else {
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
@@ -641,8 +715,7 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     size_t str_size{8500};
     std::string str = rnd.RandomString(static_cast<int>(str_size));
     size_t charge{0};
-    CacheValueChunk* chunks_head =
-        sec_cache->SplitValueIntoChunks(str, kLZ4Compression, charge);
+    CacheValueChunk* chunks_head = sec_cache->SplitValueIntoChunks(str, charge);
     ASSERT_EQ(charge, str_size + 3 * (sizeof(CacheValueChunk) - 1));
 
     CacheValueChunk* current_chunk = chunks_head;
@@ -688,12 +761,9 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     std::unique_ptr<CompressedSecondaryCache> sec_cache =
         std::make_unique<CompressedSecondaryCache>(
             CompressedSecondaryCacheOptions(1000, 0, true, 0.5, 0.0));
-    size_t charge{0};
-    CacheAllocationPtr value =
-        sec_cache->MergeChunksIntoValue(chunks_head, charge);
-    ASSERT_EQ(charge, size1 + size2 + size3);
-    std::string value_str{value.get(), charge};
-    ASSERT_EQ(strcmp(value_str.data(), str.data()), 0);
+    std::string value_str = sec_cache->MergeChunksIntoValue(chunks_head);
+    ASSERT_EQ(value_str.size(), size1 + size2 + size3);
+    ASSERT_EQ(value_str, str);
 
     while (chunks_head != nullptr) {
       CacheValueChunk* tmp_chunk = chunks_head;
@@ -725,15 +795,12 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
     size_t str_size{8500};
     std::string str = rnd.RandomString(static_cast<int>(str_size));
     size_t charge{0};
-    CacheValueChunk* chunks_head =
-        sec_cache->SplitValueIntoChunks(str, kLZ4Compression, charge);
+    CacheValueChunk* chunks_head = sec_cache->SplitValueIntoChunks(str, charge);
     ASSERT_EQ(charge, str_size + 3 * (sizeof(CacheValueChunk) - 1));
 
-    CacheAllocationPtr value =
-        sec_cache->MergeChunksIntoValue(chunks_head, charge);
-    ASSERT_EQ(charge, str_size);
-    std::string value_str{value.get(), charge};
-    ASSERT_EQ(strcmp(value_str.data(), str.data()), 0);
+    std::string value_str = sec_cache->MergeChunksIntoValue(chunks_head);
+    ASSERT_EQ(value_str.size(), str_size);
+    ASSERT_EQ(value_str, str);
 
     sec_cache->GetHelper(true)->del_cb(chunks_head, /*alloc*/ nullptr);
   }
@@ -789,8 +856,7 @@ TEST_P(CompressedSecondaryCacheTestWithCompressionParam, BasicTestFromString) {
     if (LZ4_Supported()) {
       sec_cache_uri =
           "compressed_secondary_cache://"
-          "capacity=2048;num_shard_bits=0;compression_type=kLZ4Compression;"
-          "compress_format_version=2";
+          "capacity=2048;num_shard_bits=0;compression_type=kLZ4Compression";
     } else {
       ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
       sec_cache_uri =
@@ -821,7 +887,7 @@ TEST_P(CompressedSecondaryCacheTestWithCompressionParam,
       sec_cache_uri =
           "compressed_secondary_cache://"
           "capacity=2048;num_shard_bits=0;compression_type=kLZ4Compression;"
-          "compress_format_version=2;enable_custom_split_merge=true";
+          "enable_custom_split_merge=true";
     } else {
       ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
       sec_cache_uri =
@@ -896,8 +962,8 @@ TEST_P(CompressedSecondaryCacheTestWithCompressionParam, EntryRoles) {
 
   std::shared_ptr<SecondaryCache> sec_cache = NewCompressedSecondaryCache(opts);
 
-  // Fixed seed to ensure consistent compressibility (doesn't compress)
-  std::string junk(Random(301).RandomString(1000));
+  Random rnd(301);
+  std::string junk = test::CompressibleString(&rnd, 0.5, 1000);
 
   for (uint32_t i = 0; i < kNumCacheEntryRoles; ++i) {
     CacheEntryRole role = static_cast<CacheEntryRole>(i);
@@ -930,9 +996,11 @@ TEST_P(CompressedSecondaryCacheTestWithCompressionParam, EntryRoles) {
         sec_cache_is_compressed_ && !do_not_compress.Contains(role);
     if (compressed) {
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
-                1000);
-      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
-                1007);
+                junk.length());
+      ASSERT_LT(get_perf_context()->compressed_sec_cache_compressed_bytes,
+                junk.length() * 3 / 4);
+      ASSERT_GT(get_perf_context()->compressed_sec_cache_compressed_bytes,
+                junk.length() / 4);
     } else {
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
       ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);

cache/lru_cache_test.cc

@@ -1405,9 +1405,9 @@ TEST_P(BasicSecondaryCacheTest, SaveFailTest) {
   TestItem* item1 = new TestItem(str1.data(), str1.length());
   ASSERT_OK(cache->Insert(k1.AsSlice(), item1, GetHelperFail(), str1.length()));
   std::string str2 = rnd.RandomString(1020);
+  ASSERT_EQ(secondary_cache->num_inserts(), 0u);
   TestItem* item2 = new TestItem(str2.data(), str2.length());
   // k1 should be demoted to NVM
-  ASSERT_EQ(secondary_cache->num_inserts(), 0u);
   ASSERT_OK(cache->Insert(k2.AsSlice(), item2, GetHelperFail(), str2.length()));
   ASSERT_EQ(secondary_cache->num_inserts(), 1u);
 
@@ -1503,7 +1503,7 @@ TEST_P(BasicSecondaryCacheTest, FullCapacityTest) {
         /*context*/ this, Cache::Priority::LOW);
     ASSERT_EQ(handle1, nullptr);
 
-    // k1 promotion can fail with strict_capacit_limit=true, but Lookup still
+    // k1 promotion can fail with strict_capacity_limit=true, but Lookup still
     // succeeds using a standalone handle
     handle1 = cache->Lookup(k1.AsSlice(), GetHelper(),
                             /*context*/ this, Cache::Priority::LOW);
@@ -1680,7 +1680,7 @@ TEST_P(DBSecondaryCacheTest, TestSecondaryCacheCorrectness2) {
   // After Flush is successful, RocksDB will do the paranoid check for the new
   // SST file. Meta blocks are always cached in the block cache and they
   // will not be evicted. When block_2 is cache miss and read out, it is
-  // inserted to the block cache. Thefore, block_1 is evicted from block
+  // inserted to the block cache. Therefore, block_1 is evicted from block
   // cache and successfully inserted to the secondary cache. Here are 2
   // lookups in the secondary cache for block_1 and block_2.
   ASSERT_EQ(secondary_cache->num_inserts(), 1u);
@@ -1721,7 +1721,7 @@ TEST_P(DBSecondaryCacheTest, TestSecondaryCacheCorrectness2) {
   v = Get(Key(0));
   ASSERT_EQ(1007, v.size());
   // This Get needs to access block_1, since block_1 is not in block cache
-  // there is one econdary cache lookup. Then, block_1 is cached in the
+  // there is one secondary cache lookup. Then, block_1 is cached in the
   // block cache.
   ASSERT_EQ(secondary_cache->num_inserts(), 2u);
   ASSERT_EQ(secondary_cache->num_lookups(), 5u);
@@ -1785,7 +1785,7 @@ TEST_P(DBSecondaryCacheTest, NoSecondaryCacheInsertion) {
   std::string v = Get(Key(0));
   ASSERT_EQ(1000, v.size());
   // Since the block cache is large enough, all the blocks are cached. we
-  // do not need to lookup the seondary cache.
+  // do not need to lookup the secondary cache.
   ASSERT_EQ(secondary_cache->num_inserts(), 0u);
   ASSERT_EQ(secondary_cache->num_lookups(), 2u);
 
@@ -2150,7 +2150,7 @@ TEST_P(DBSecondaryCacheTest, LRUCacheDumpLoadBasic) {
   ASSERT_OK(Flush());
   Compact("a", "z");
 
-  // do th eread for all the key value pairs, so all the blocks should be in
+  // do the read for all the key value pairs, so all the blocks should be in
   // cache
   uint32_t start_insert = cache->GetInsertCount();
   uint32_t start_lookup = cache->GetLookupcount();
@@ -2179,7 +2179,7 @@ TEST_P(DBSecondaryCacheTest, LRUCacheDumpLoadBasic) {
                             &cache_dumper);
   ASSERT_OK(s);
   std::vector<DB*> db_list;
-  db_list.push_back(db_);
+  db_list.push_back(db_.get());
   s = cache_dumper->SetDumpFilter(db_list);
   ASSERT_OK(s);
   s = cache_dumper->DumpCacheEntriesToWriter();
@@ -2263,11 +2263,11 @@ TEST_P(DBSecondaryCacheTest, LRUCacheDumpLoadWithFilter) {
   options.env = fault_env_.get();
   std::string dbname1 = test::PerThreadDBPath("db_1");
   ASSERT_OK(DestroyDB(dbname1, options));
-  DB* db1 = nullptr;
+  std::unique_ptr<DB> db1;
   ASSERT_OK(DB::Open(options, dbname1, &db1));
   std::string dbname2 = test::PerThreadDBPath("db_2");
   ASSERT_OK(DestroyDB(dbname2, options));
-  DB* db2 = nullptr;
+  std::unique_ptr<DB> db2;
   ASSERT_OK(DB::Open(options, dbname2, &db2));
   fault_fs_->SetFailGetUniqueId(true);
 
@@ -2335,7 +2335,7 @@ TEST_P(DBSecondaryCacheTest, LRUCacheDumpLoadWithFilter) {
                             &cache_dumper);
   ASSERT_OK(s);
   std::vector<DB*> db_list;
-  db_list.push_back(db1);
+  db_list.push_back(db1.get());
   s = cache_dumper->SetDumpFilter(db_list);
   ASSERT_OK(s);
   s = cache_dumper->DumpCacheEntriesToWriter();
@@ -2377,7 +2377,7 @@ TEST_P(DBSecondaryCacheTest, LRUCacheDumpLoadWithFilter) {
   ASSERT_OK(s);
 
   ASSERT_OK(db1->Close());
-  delete db1;
+  db1.reset();
   ASSERT_OK(DB::Open(options, dbname1, &db1));
 
   // After load, we do the Get again. To validate the cache, we do not allow any
@@ -2406,8 +2406,8 @@ TEST_P(DBSecondaryCacheTest, LRUCacheDumpLoadWithFilter) {
   ASSERT_EQ(256, static_cast<int>(block_lookup));
   fault_fs_->SetFailGetUniqueId(false);
   fault_fs_->SetFilesystemActive(true);
-  delete db1;
-  delete db2;
+  db1.reset();
+  db2.reset();
   ASSERT_OK(DestroyDB(dbname1, options));
   ASSERT_OK(DestroyDB(dbname2, options));
 }
@@ -2464,7 +2464,7 @@ TEST_P(DBSecondaryCacheTest, TestSecondaryCacheOptionBasic) {
   std::string v = Get(Key(0));
   ASSERT_EQ(1007, v.size());
 
-  // Check the data in first block. Cache miss, direclty read from SST file.
+  // Check the data in first block. Cache miss, directly read from SST file.
   ASSERT_EQ(secondary_cache->num_inserts(), 0u);
   ASSERT_EQ(secondary_cache->num_lookups(), 0u);
 
@@ -2598,7 +2598,7 @@ TEST_P(DBSecondaryCacheTest, TestSecondaryCacheOptionChange) {
 }
 
 // Two DB test. We create 2 DBs sharing the same block cache and secondary
-// cache. We diable the secondary cache option for DB2.
+// cache. We disable the secondary cache option for DB2.
 TEST_P(DBSecondaryCacheTest, TestSecondaryCacheOptionTwoDB) {
   if (IsHyperClock()) {
     ROCKSDB_GTEST_BYPASS("Test depends on LRUCache-specific behaviors");
@@ -2619,11 +2619,11 @@ TEST_P(DBSecondaryCacheTest, TestSecondaryCacheOptionTwoDB) {
   options.paranoid_file_checks = true;
   std::string dbname1 = test::PerThreadDBPath("db_t_1");
   ASSERT_OK(DestroyDB(dbname1, options));
-  DB* db1 = nullptr;
+  std::unique_ptr<DB> db1;
   ASSERT_OK(DB::Open(options, dbname1, &db1));
   std::string dbname2 = test::PerThreadDBPath("db_t_2");
   ASSERT_OK(DestroyDB(dbname2, options));
-  DB* db2 = nullptr;
+  std::unique_ptr<DB> db2;
   Options options2 = options;
   options2.lowest_used_cache_tier = CacheTier::kVolatileTier;
   ASSERT_OK(DB::Open(options2, dbname2, &db2));
@@ -2700,8 +2700,8 @@ TEST_P(DBSecondaryCacheTest, TestSecondaryCacheOptionTwoDB) {
 
   fault_fs_->SetFailGetUniqueId(false);
   fault_fs_->SetFilesystemActive(true);
-  delete db1;
-  delete db2;
+  db1.reset();
+  db2.reset();
   ASSERT_OK(DestroyDB(dbname1, options));
   ASSERT_OK(DestroyDB(dbname2, options));
 }

cache/secondary_cache_adapter.cc

@@ -33,7 +33,7 @@ const char* kTieredCacheName = "TieredCache";
 // proportionally across the primary/secondary caches.
 //
 // The primary block cache is initially sized to the sum of the primary cache
-// budget + teh secondary cache budget, as follows -
+// budget + the secondary cache budget, as follows -
 //   |---------    Primary Cache Configured Capacity  -----------|
 //   |---Secondary Cache Budget----|----Primary Cache Budget-----|
 //
@@ -51,7 +51,7 @@ const char* kTieredCacheName = "TieredCache";
 // placeholder is counted against the primary cache. To compensate and count
 // a portion of it against the secondary cache, the secondary cache Deflate()
 // method is called to shrink it. Since the Deflate() causes the secondary
-// actual usage to shrink, it is refelcted here by releasing an equal amount
+// actual usage to shrink, it is reflected here by releasing an equal amount
 // from the pri_cache_res_ reservation. The Deflate() in the secondary cache
 // can be, but is not required to be, implemented using its own cache
 // reservation manager.
@@ -72,7 +72,7 @@ const char* kTieredCacheName = "TieredCache";
 // reservation is increased by an equal amount.
 //
 // Another way of implementing this would have been to simply split the user
-// reservation into primary and seconary components. However, this would
+// reservation into primary and secondary components. However, this would
 // require allocating a structure to track the associated secondary cache
 // reservation, which adds some complexity and overhead.
 //
@@ -121,7 +121,14 @@ CacheWithSecondaryAdapter::~CacheWithSecondaryAdapter() {
     assert(s.ok());
     assert(placeholder_usage_ == 0);
     assert(reserved_usage_ == 0);
-    assert(pri_cache_res_->GetTotalMemoryUsed() == sec_capacity);
+    if (pri_cache_res_->GetTotalMemoryUsed() != sec_capacity) {
+      fprintf(stdout,
+              "~CacheWithSecondaryAdapter: Primary cache reservation: "
+              "%zu, Secondary cache capacity: %zu, "
+              "Secondary cache reserved: %zu\n",
+              pri_cache_res_->GetTotalMemoryUsed(), sec_capacity,
+              sec_reserved_);
+    }
   }
 #endif  // NDEBUG
 }
@@ -479,12 +486,10 @@ const char* CacheWithSecondaryAdapter::Name() const {
 // as well. At the moment, we don't have a good way of handling the case
 // where the new capacity < total cache reservations.
 void CacheWithSecondaryAdapter::SetCapacity(size_t capacity) {
-  size_t sec_capacity = static_cast<size_t>(
-      capacity * (distribute_cache_res_ ? sec_cache_res_ratio_ : 0.0));
-  size_t old_sec_capacity = 0;
-
   if (distribute_cache_res_) {
     MutexLock m(&cache_res_mutex_);
+    size_t sec_capacity = static_cast<size_t>(capacity * sec_cache_res_ratio_);
+    size_t old_sec_capacity = 0;
 
     Status s = secondary_cache_->GetCapacity(old_sec_capacity);
     if (!s.ok()) {
@@ -579,7 +584,7 @@ Status CacheWithSecondaryAdapter::UpdateCacheReservationRatio(
   size_t pri_capacity = target_->GetCapacity();
   size_t sec_capacity =
       static_cast<size_t>(pri_capacity * compressed_secondary_ratio);
-  size_t old_sec_capacity;
+  size_t old_sec_capacity = 0;
   Status s = secondary_cache_->GetCapacity(old_sec_capacity);
   if (!s.ok()) {
     return s;
@@ -603,6 +608,7 @@ Status CacheWithSecondaryAdapter::UpdateCacheReservationRatio(
     //    cache utilization (increase in capacity - increase in share of cache
     //    reservation)
     // 3. Increase secondary cache capacity
+    assert(new_sec_reserved >= sec_reserved_);
     s = secondary_cache_->Deflate(new_sec_reserved - sec_reserved_);
     assert(s.ok());
     s = pri_cache_res_->UpdateCacheReservation(
@@ -615,7 +621,7 @@ Status CacheWithSecondaryAdapter::UpdateCacheReservationRatio(
   } else {
     // We're shrinking the ratio. Try to avoid unnecessary evictions -
     // 1. Lower the secondary cache capacity
-    // 2. Decrease pri_cache_res_ reservation to relect lower secondary
+    // 2. Decrease pri_cache_res_ reservation to reflect lower secondary
     //    cache utilization (decrease in capacity - decrease in share of cache
     //    reservations)
     // 3. Inflate the secondary cache to give it back the reduction in its

ccache_msvc_compiler.bat

@@ -0,0 +1 @@
+ccache.exe cl.exe %*

claude_md/add_option.md

@@ -0,0 +1,512 @@
+# Adding New Options to RocksDB Public API
+
+This document provides guidance on how to add new options to RocksDB's public API. There are two main categories of options:
+
+1. **Standard Column Family Options** (Options/DBOptions/AdvancedColumnFamilyOptions)
+2. **BlockBasedTableOptions** (options specific to block-based table format)
+
+## Overview of Files to Modify
+
+### For Standard Column Family Options
+
+| File | Purpose |
+|------|---------|
+| `include/rocksdb/advanced_options.h` | Define the option with documentation |
+| `include/rocksdb/options.h` | Add reference in related option groups if needed |
+| `options/cf_options.h` | Add to `MutableCFOptions` or `ImmutableCFOptions` struct |
+| `options/cf_options.cc` | Register option for serialization/deserialization and logging |
+| `options/options_helper.cc` | Add to `UpdateColumnFamilyOptions()` for mutable options |
+| `options/options_settable_test.cc` | Add to test string for option parsing |
+| `db_stress_tool/db_stress_common.h` | Declare gflag |
+| `db_stress_tool/db_stress_gflags.cc` | Define gflag with default value |
+| `db_stress_tool/db_stress_test_base.cc` | Apply flag to options |
+| `tools/db_bench_tool.cc` | Add flag definition and apply to options |
+| `tools/db_crashtest.py` | Add randomized values for stress testing |
+| `unreleased_history/new_features/` | Add release note markdown file |
+
+### For BlockBasedTableOptions
+
+| File | Purpose |
+|------|---------|
+| `include/rocksdb/table.h` | Define the option in `BlockBasedTableOptions` struct |
+| `table/block_based/block_based_table_factory.cc` | Register for serialization, validation, and printing |
+| `options/options_settable_test.cc` | Add to `BlockBasedTableOptionsAllFieldsSettable` test |
+| `options/options_test.cc` | Add to `MutableCFOptions` test if applicable |
+| `db_stress_tool/db_stress_common.h` | Declare gflag |
+| `db_stress_tool/db_stress_gflags.cc` | Define gflag |
+| `db_stress_tool/db_stress_test_base.cc` | Apply flag to `block_based_options` |
+| `tools/db_bench_tool.cc` | Add flag definition and apply to `block_based_options` |
+| `tools/db_crashtest.py` | Add randomized values |
+| `java/src/main/java/org/rocksdb/BlockBasedTableConfig.java` | Java API |
+| `java/rocksjni/portal.h` | JNI portal for Java bindings |
+| `java/rocksjni/table.cc` | JNI implementation |
+| `java/src/test/java/org/rocksdb/BlockBasedTableConfigTest.java` | Java unit test |
+
+---
+
+## Pattern 1: Adding a Standard Column Family Option
+
+Example reference: commit `94e65a2e0b4f817aa4bfa4c96cdf867e7980d7bc` (memtable_veirfy_per_key_checksum_on_seek)
+
+### Step 1: Define the Option in Public Header
+
+**File: `include/rocksdb/advanced_options.h`**
+
+Add the option with documentation in `AdvancedColumnFamilyOptions` struct:
+
+```cpp
+// Enables additional integrity checks during seek.
+// Specifically, for skiplist-based memtables, key checksum validation could
+// be enabled during seek optionally. This is helpful to detect corrupted
+// memtable keys during reads. Enabling this feature incurs a performance
+// overhead due to additional key checksum validation during memtable seek
+// operation.
+// This option depends on memtable_protection_bytes_per_key to be non zero.
+// If memtable_protection_bytes_per_key is zero, no validation is performed.
+bool memtable_veirfy_per_key_checksum_on_seek = false;
+```
+
+### Step 2: Add to Internal Options Structs
+
+**File: `options/cf_options.h`**
+
+Add to `MutableCFOptions` struct (or `ImmutableCFOptions` for immutable options):
+
+```cpp
+// In MutableCFOptions constructor from Options:
+memtable_veirfy_per_key_checksum_on_seek(
+    options.memtable_veirfy_per_key_checksum_on_seek),
+
+// In MutableCFOptions default constructor:
+memtable_veirfy_per_key_checksum_on_seek(false),
+
+// In MutableCFOptions struct member declarations:
+bool memtable_veirfy_per_key_checksum_on_seek;
+```
+
+### Step 3: Register for Serialization/Deserialization
+
+**File: `options/cf_options.cc`**
+
+Add to the options type info map for serialization:
+
+```cpp
+{"memtable_veirfy_per_key_checksum_on_seek",
+ {offsetof(struct MutableCFOptions,
+           memtable_veirfy_per_key_checksum_on_seek),
+  OptionType::kBoolean, OptionVerificationType::kNormal,
+  OptionTypeFlags::kMutable}},
+```
+
+Add logging in `MutableCFOptions::Dump()`:
+
+```cpp
+ROCKS_LOG_INFO(log, "memtable_veirfy_per_key_checksum_on_seek: %d",
+               memtable_veirfy_per_key_checksum_on_seek);
+```
+
+### Step 4: Update Options Helper
+
+**File: `options/options_helper.cc`**
+
+Add to `UpdateColumnFamilyOptions()`:
+
+```cpp
+cf_opts->memtable_veirfy_per_key_checksum_on_seek =
+    moptions.memtable_veirfy_per_key_checksum_on_seek;
+```
+
+### Step 5: Add to Options Settable Test
+
+**File: `options/options_settable_test.cc`**
+
+Add to the test string in `ColumnFamilyOptionsAllFieldsSettable`:
+
+```cpp
+"memtable_veirfy_per_key_checksum_on_seek=1;"
+```
+
+### Step 6: Add db_stress Support
+
+**File: `db_stress_tool/db_stress_common.h`**
+
+```cpp
+DECLARE_bool(memtable_veirfy_per_key_checksum_on_seek);
+```
+
+**File: `db_stress_tool/db_stress_gflags.cc`**
+
+```cpp
+DEFINE_bool(
+    memtable_veirfy_per_key_checksum_on_seek,
+    ROCKSDB_NAMESPACE::Options().memtable_veirfy_per_key_checksum_on_seek,
+    "Sets CF option memtable_veirfy_per_key_checksum_on_seek.");
+```
+
+**File: `db_stress_tool/db_stress_test_base.cc`**
+
+```cpp
+options.memtable_veirfy_per_key_checksum_on_seek =
+    FLAGS_memtable_veirfy_per_key_checksum_on_seek;
+```
+
+### Step 7: Add db_bench Support
+
+**File: `tools/db_bench_tool.cc`**
+
+```cpp
+// Flag definition (near related flags):
+DEFINE_bool(memtable_veirfy_per_key_checksum_on_seek, false,
+            "Sets CF option memtable_veirfy_per_key_checksum_on_seek");
+
+// Apply flag to options (in InitializeOptionsFromFlags or similar):
+options.memtable_veirfy_per_key_checksum_on_seek =
+    FLAGS_memtable_veirfy_per_key_checksum_on_seek;
+```
+
+### Step 8: Add Crash Test Support
+
+**File: `tools/db_crashtest.py`**
+
+```python
+"memtable_veirfy_per_key_checksum_on_seek": lambda: random.choice([0] * 7 + [1]),
+```
+
+Also add constraint handling in `finalize_and_sanitize()` if needed:
+
+```python
+# only skip list memtable representation supports paranoid memory checks
+if dest_params.get("memtablerep") != "skip_list":
+    dest_params["memtable_veirfy_per_key_checksum_on_seek"] = 0
+```
+
+### Step 9: Add Release Note
+
+**File: `unreleased_history/new_features/<descriptive_name>.md`**
+
+```markdown
+A new flag memtable_veirfy_per_key_checksum_on_seek is added to AdvancedColumnFamilyOptions. When it is enabled, it will validate key checksum along the binary search path on skiplist based memtable during seek operation.
+```
+
+---
+
+## Pattern 2: Adding a BlockBasedTableOptions Option
+
+Example reference: commit `742741b175c5f238374c1714f9db3340d49de569` (super_block_alignment_size)
+
+### Step 1: Define the Option in Public Header
+
+**File: `include/rocksdb/table.h`**
+
+Add to `BlockBasedTableOptions` struct with documentation:
+
+```cpp
+// Align data blocks on super block alignment. Avoid a data block split across
+// super block boundaries. Works with/without compression.
+//
+// Here a "super block" refers to an aligned unit of underlying Filesystem
+// storage for which there is an extra cost when a random read involves two
+// such super blocks instead of just one. Configuring that size here suggests
+// inserting padding in the SST file to avoid a single SST block splitting
+// across two super blocks. Only power-of-two sizes are supported. See also
+// super_block_alignment_space_overhead_ratio. Default to 0, which means super
+// block alignment is disabled.
+size_t super_block_alignment_size = 0;
+
+// This option controls the storage space overhead of super block alignment.
+// It is used to calculate the max padding size allowed for super block
+// alignment. It is calculated in this way. If super_block_alignment_size is
+// 2MB, and super_block_alignment_overhead_ratio is 128, then the max padding
+// size allowed for super block alignment is 2MB / 128 = 16KB.
+// Note that, when it is set to 0, super block alignment is disabled.
+size_t super_block_alignment_space_overhead_ratio = 128;
+```
+
+### Step 2: Register for Serialization in Table Factory
+
+**File: `table/block_based/block_based_table_factory.cc`**
+
+Add to the type info map:
+
+```cpp
+{"super_block_alignment_size",
+ {offsetof(struct BlockBasedTableOptions, super_block_alignment_size),
+  OptionType::kSizeT, OptionVerificationType::kNormal}},
+{"super_block_alignment_space_overhead_ratio",
+ {offsetof(struct BlockBasedTableOptions,
+           super_block_alignment_space_overhead_ratio),
+  OptionType::kSizeT, OptionVerificationType::kNormal}},
+```
+
+Add validation in `ValidateOptions()`:
+
+```cpp
+if ((table_options_.super_block_alignment_size &
+     (table_options_.super_block_alignment_size - 1))) {
+  return Status::InvalidArgument(
+      "Super Block alignment requested but super block alignment size is not "
+      "a power of 2");
+}
+if (table_options_.super_block_alignment_size >
+    std::numeric_limits<uint32_t>::max()) {
+  return Status::InvalidArgument(
+      "Super block alignment size exceeds maximum number (4GiB) allowed");
+}
+```
+
+Add printing in `GetPrintableOptions()`:
+
+```cpp
+snprintf(buffer, kBufferSize,
+         "  super_block_alignment_size: %" ROCKSDB_PRIszt "\n",
+         table_options_.super_block_alignment_size);
+ret.append(buffer);
+```
+
+### Step 3: Add to Options Settable Test
+
+**File: `options/options_settable_test.cc`**
+
+Add to `BlockBasedTableOptionsAllFieldsSettable` test:
+
+```cpp
+"super_block_alignment_size=65536;"
+"super_block_alignment_space_overhead_ratio=4096;"
+```
+
+### Step 4: Add to Options Test
+
+**File: `options/options_test.cc`**
+
+```cpp
+ASSERT_OK(GetColumnFamilyOptionsFromString(
+    config_options, cf_opts,
+    "block_based_table_factory.super_block_alignment_size=65536; "
+    "block_based_table_factory.super_block_alignment_space_overhead_ratio=4096;",
+    &cf_opts));
+ASSERT_EQ(bbto->super_block_alignment_size, 65536);
+ASSERT_EQ(bbto->super_block_alignment_space_overhead_ratio, 4096);
+```
+
+### Step 5: Add db_stress Support
+
+**File: `db_stress_tool/db_stress_common.h`**
+
+```cpp
+DECLARE_uint64(super_block_alignment_size);
+DECLARE_uint64(super_block_alignment_space_overhead_ratio);
+```
+
+**File: `db_stress_tool/db_stress_gflags.cc`**
+
+```cpp
+DEFINE_uint64(
+    super_block_alignment_size,
+    ROCKSDB_NAMESPACE::BlockBasedTableOptions().super_block_alignment_size,
+    "BlockBasedTableOptions.super_block_alignment_size");
+
+DEFINE_uint64(
+    super_block_alignment_space_overhead_ratio,
+    ROCKSDB_NAMESPACE::BlockBasedTableOptions()
+        .super_block_alignment_space_overhead_ratio,
+    "BlockBasedTableOptions.super_block_alignment_space_overhead_ratio");
+```
+
+**File: `db_stress_tool/db_stress_test_base.cc`**
+
+```cpp
+block_based_options.super_block_alignment_size =
+    fLU64::FLAGS_super_block_alignment_size;
+block_based_options.super_block_alignment_space_overhead_ratio =
+    fLU64::FLAGS_super_block_alignment_space_overhead_ratio;
+```
+
+### Step 6: Add db_bench Support
+
+**File: `tools/db_bench_tool.cc`**
+
+```cpp
+// Flag definitions:
+DEFINE_uint64(
+    super_block_alignment_size,
+    ROCKSDB_NAMESPACE::BlockBasedTableOptions().super_block_alignment_size,
+    "Configure super block size");
+
+DEFINE_uint64(super_block_alignment_space_overhead_ratio,
+              ROCKSDB_NAMESPACE::BlockBasedTableOptions()
+                  .super_block_alignment_space_overhead_ratio,
+              "Configure space overhead for super block alignment");
+
+// Apply to block_based_options (in the block where other options are set):
+block_based_options.super_block_alignment_size = FLAGS_super_block_alignment_size;
+block_based_options.super_block_alignment_space_overhead_ratio =
+    FLAGS_super_block_alignment_space_overhead_ratio;
+```
+
+### Step 7: Add Crash Test Support
+
+**File: `tools/db_crashtest.py`**
+
+```python
+"super_block_alignment_size": lambda: random.choice(
+    [0, 128 * 1024, 512 * 1024, 2 * 1024 * 1024]
+),
+"super_block_alignment_space_overhead_ratio": lambda: random.choice([0, 32, 4096]),
+```
+
+### Step 8: Add Java API Support
+
+**File: `java/src/main/java/org/rocksdb/BlockBasedTableConfig.java`**
+
+Add getter and setter methods:
+
+```java
+/**
+ * Get the super block alignment size.
+ *
+ * @return the super block alignment size.
+ */
+public long superBlockAlignmentSize() {
+  return superBlockAlignmentSize;
+}
+
+/**
+ * Set the super block alignment size.
+ * When set to 0, super block alignment is disabled.
+ *
+ * @param superBlockAlignmentSize the super block alignment size.
+ *
+ * @return the reference to the current option.
+ */
+public BlockBasedTableConfig setSuperBlockAlignmentSize(final long superBlockAlignmentSize) {
+  this.superBlockAlignmentSize = superBlockAlignmentSize;
+  return this;
+}
+```
+
+Add member variable:
+
+```java
+private long superBlockAlignmentSize;
+```
+
+Update constructor and native method signature.
+
+**File: `java/rocksjni/portal.h`**
+
+Update `GetMethodID` signature and add fields to Java object construction.
+
+**File: `java/rocksjni/table.cc`**
+
+Add parameters to JNI function and apply to options.
+
+**File: `java/src/test/java/org/rocksdb/BlockBasedTableConfigTest.java`**
+
+Add unit tests:
+
+```java
+@Test
+public void superBlockAlignmentSize() {
+  final BlockBasedTableConfig blockBasedTableConfig = new BlockBasedTableConfig();
+  blockBasedTableConfig.setSuperBlockAlignmentSize(1024 * 1024);
+  assertThat(blockBasedTableConfig.superBlockAlignmentSize()).isEqualTo(1024 * 1024);
+}
+```
+
+---
+
+## Pattern 3: Adding C API for Existing Option
+
+Example reference: commit `429b36c22d76403d275dd0e6877b08d4cea2bc90` (block_align C API)
+
+If an option already exists but needs C API support:
+
+**File: `db/c.cc`**
+
+```cpp
+void rocksdb_block_based_options_set_block_align(
+    rocksdb_block_based_table_options_t* options, unsigned char v) {
+  options->rep.block_align = v;
+}
+```
+
+**File: `include/rocksdb/c.h`**
+
+```cpp
+extern ROCKSDB_LIBRARY_API void rocksdb_block_based_options_set_block_align(
+    rocksdb_block_based_table_options_t*, unsigned char);
+```
+
+---
+
+## Unit Testing Guidelines
+
+### For Standard Options
+
+Add tests in appropriate test files (e.g., `db/db_memtable_test.cc`, `db/db_options_test.cc`):
+
+```cpp
+TEST_F(DBMemTableTest, YourOptionTest) {
+  Options options;
+  options.your_new_option = true;
+  Reopen(options);
+  // Test the behavior
+}
+```
+
+### For BlockBasedTableOptions
+
+Add tests in `db/db_flush_test.cc`, `table/block_based/block_based_table_reader_test.cc`, or `table/table_test.cc`:
+
+```cpp
+TEST_P(DBFlushYourFeatureTest, YourFeature) {
+  Options options;
+  BlockBasedTableOptions block_options;
+  block_options.your_new_option = some_value;
+  options.table_factory.reset(NewBlockBasedTableFactory(block_options));
+
+  ASSERT_OK(options.table_factory->ValidateOptions(
+      DBOptions(options), ColumnFamilyOptions(options)));
+
+  Reopen(options);
+  // Test the behavior
+}
+```
+
+---
+
+## Option Type Reference
+
+Common option types used in serialization:
+
+| OptionType | C++ Type | Example |
+|------------|----------|---------|
+| `kBoolean` | `bool` | `paranoid_memory_checks` |
+| `kInt` | `int` | `max_write_buffer_number` |
+| `kInt32T` | `int32_t` | `level0_file_num_compaction_trigger` |
+| `kUInt32T` | `uint32_t` | `memtable_protection_bytes_per_key` |
+| `kUInt64T` | `uint64_t` | `target_file_size_base` |
+| `kSizeT` | `size_t` | `block_size` |
+| `kDouble` | `double` | `compression_ratio` |
+| `kString` | `std::string` | `db_log_dir` |
+
+---
+
+## Checklist Summary
+
+- [ ] Public header file with option definition and documentation
+- [ ] Internal options struct (MutableCFOptions or ImmutableCFOptions)
+- [ ] Options serialization/deserialization registration
+- [ ] Options logging in Dump() method
+- [ ] UpdateColumnFamilyOptions() for mutable options
+- [ ] options_settable_test.cc
+- [ ] db_stress_common.h (DECLARE)
+- [ ] db_stress_gflags.cc (DEFINE)
+- [ ] db_stress_test_base.cc (apply flag)
+- [ ] db_bench_tool.cc (DEFINE and apply)
+- [ ] db_crashtest.py (randomized values)
+- [ ] Unit tests
+- [ ] unreleased_history markdown file
+- [ ] Java API (for BlockBasedTableOptions)
+- [ ] C API (if needed)
+

claude_md/add_public_api.md

@@ -0,0 +1,504 @@
+# RocksDB API Development Guide
+
+This document provides guidance for adding new public APIs to RocksDB, following the established patterns used by existing APIs like `CompactRange`.
+
+## API Layer Architecture
+
+RocksDB exposes public APIs through multiple layers. Users can access RocksDB through any of the three public APIs: C++ headers, C headers, or Java bindings.
+
+Here is an example for public header db.h:
+
+```
+┌─────────────────────────────────────────────────────────────────────────────┐
+│                     Level 1: Public APIs (User Entry Points)                │
+├───────────────────────┬─────────────────────────┬───────────────────────────┤
+│   C++ Public API      │     C API Bindings      │       Java/JNI API        │
+│ include/rocksdb/db.h  │   include/rocksdb/c.h   │ java/src/.../RocksDB.java │
+│ include/rocksdb/*.h   │                         │ java/src/.../*.java       │
+└───────────────────────┴────────────┬────────────┴───────────────────────────┘
+                                     ↓
+┌─────────────────────────────────────────────────────────────────────────────┐
+│              Level 2: C++ Implementation (Internal Core)                    │
+│              db/db_impl/db_impl*.cc, db/c.cc, java/rocksjni/*.cc            │
+└─────────────────────────────────────────────────────────────────────────────┘
+```
+
+## Step-by-Step Guide: Adding a New Public API
+
+### Step 1: Define the C++ Public Interface
+
+**File:** `include/rocksdb/db.h`
+
+Add the virtual method declaration in the `DB` class:
+
+\`\`\`cpp
+// Pure virtual - must be implemented by DBImpl
+virtual Status YourNewAPI(const YourAPIOptions& options,
+                          ColumnFamilyHandle* column_family,
+                          /* other params */) = 0;
+
+// Convenience overload for default column family
+virtual Status YourNewAPI(const YourAPIOptions& options,
+                          /* other params */) {
+  return YourNewAPI(options, DefaultColumnFamily(), /* other params */);
+}
+\`\`\`
+
+**Key Patterns:**
+- Use `Status` return type for error handling
+- Use `OptSlice` to avoid unnecessary levels of indirection and use of raw pointers.
+- Use `ColumnFamilyHandle*` for column family support
+- Provide convenience overloads for the default column family
+
+### Step 2: Define Options Struct (If Needed)
+
+**File:** `include/rocksdb/options.h`
+
+If your API has multiple configuration options, define an options struct:
+
+\`\`\`cpp
+struct YourAPIOptions {
+  // Document each option with clear comments
+  bool some_boolean_option = false;
+
+  // Default value explanation
+  int some_int_option = -1;
+
+  // Pointer options require careful lifetime management
+  std::atomic<bool>* canceled = nullptr;
+
+  // Enum options for multi-choice settings
+  YourEnumType some_enum = YourEnumType::kDefault;
+};
+\`\`\`
+
+**Key Patterns:**
+- Use sensible default values specified inline (e.g., `= false`, `= -1`)
+- Do NOT redundantly document the default value in comments; instead, document the rationale (why this default), historical context, and how different values are interpreted
+- Group related options logically
+- Consider thread-safety for pointer options
+
+### Step 3: Implement in DBImpl
+
+**Header:** `db/db_impl/db_impl.h`
+
+\`\`\`cpp
+using DB::YourNewAPI;
+Status YourNewAPI(const YourAPIOptions& options,
+                  ColumnFamilyHandle* column_family,
+                  /* other params */) override;
+
+// Private internal implementation if needed
+Status YourNewAPIInternal(const YourAPIOptions& options,
+                          ColumnFamilyHandle* column_family,
+                          /* other params */);
+\`\`\`
+
+**Implementation:** `db/db_impl/db_impl_<category>.cc`
+
+Choose the appropriate implementation file based on functionality:
+- `db_impl_compaction_flush.cc` - Compaction and flush operations
+- `db_impl_write.cc` - Write operations
+- `db_impl_open.cc` - DB opening/closing
+- `db_impl_files.cc` - File operations
+- `db_impl.cc` - General operations
+
+\`\`\`cpp
+Status DBImpl::YourNewAPI(const YourAPIOptions& options,
+                          ColumnFamilyHandle* column_family,
+                          /* other params */) {
+  // 1. Input validation
+  if (/* invalid input */) {
+    return Status::InvalidArgument("Error message");
+  }
+
+  // 2. Check for cancellation/abort conditions
+  if (options.canceled && options.canceled->load(std::memory_order_acquire)) {
+    return Status::Incomplete(Status::SubCode::kManualCompactionPaused);
+  }
+
+  // 3. Get column family data
+  auto cfh = static_cast<ColumnFamilyHandleImpl*>(column_family);
+  auto cfd = cfh->cfd();
+
+  // 4. Core implementation logic
+  // ...
+
+  return Status::OK();
+}
+\`\`\`
+
+### Step 4: Handle Special DB Types
+
+**StackableDB (Wrapper DBs):**
+**File:** `include/rocksdb/utilities/stackable_db.h`
+
+\`\`\`cpp
+using DB::YourNewAPI;
+Status YourNewAPI(const YourAPIOptions& options,
+                  ColumnFamilyHandle* column_family,
+                  /* other params */) override {
+  return db_->YourNewAPI(options, column_family, /* other params */);
+}
+\`\`\`
+
+**Secondary DB (Read-Only):**
+**File:** `db/db_impl/db_impl_secondary.h`
+
+\`\`\`cpp
+using DBImpl::YourNewAPI;
+Status YourNewAPI(const YourAPIOptions& /*options*/,
+                  ColumnFamilyHandle* /*column_family*/,
+                  /* other params */) override {
+  return Status::NotSupported("Not supported in secondary DB");
+}
+\`\`\`
+
+**CompactedDB (Read-Only):**
+**File:** `db/db_impl/compacted_db_impl.h`
+
+\`\`\`cpp
+using DBImpl::YourNewAPI;
+Status YourNewAPI(const YourAPIOptions& /*options*/,
+                  ColumnFamilyHandle* /*column_family*/,
+                  /* other params */) override {
+  return Status::NotSupported("Not supported for read-only DB");
+}
+\`\`\`
+
+### Step 5: Add C API Bindings
+
+**Header:** `include/rocksdb/c.h`
+
+\`\`\`c
+// Basic version
+extern ROCKSDB_LIBRARY_API void rocksdb_your_new_api(
+    rocksdb_t* db,
+    const char* start_key, size_t start_key_len,
+    const char* limit_key, size_t limit_key_len);
+
+// Column family version
+extern ROCKSDB_LIBRARY_API void rocksdb_your_new_api_cf(
+    rocksdb_t* db, rocksdb_column_family_handle_t* column_family,
+    const char* start_key, size_t start_key_len,
+    const char* limit_key, size_t limit_key_len);
+
+// With options and error handling
+extern ROCKSDB_LIBRARY_API void rocksdb_your_new_api_opt(
+    rocksdb_t* db, rocksdb_your_api_options_t* opt,
+    const char* start_key, size_t start_key_len,
+    const char* limit_key, size_t limit_key_len,
+    char** errptr);
+\`\`\`
+
+**Implementation:** `db/c.cc`
+
+\`\`\`cpp
+void rocksdb_your_new_api(rocksdb_t* db, const char* start_key,
+                          size_t start_key_len, const char* limit_key,
+                          size_t limit_key_len) {
+  Slice a, b;
+  db->rep->YourNewAPI(
+      YourAPIOptions(),  // Default options
+      (start_key ? (a = Slice(start_key, start_key_len), &a) : nullptr),
+      (limit_key ? (b = Slice(limit_key, limit_key_len), &b) : nullptr));
+}
+
+void rocksdb_your_new_api_cf(rocksdb_t* db,
+                             rocksdb_column_family_handle_t* column_family,
+                             const char* start_key, size_t start_key_len,
+                             const char* limit_key, size_t limit_key_len) {
+  Slice a, b;
+  db->rep->YourNewAPI(
+      YourAPIOptions(),
+      column_family->rep,
+      (start_key ? (a = Slice(start_key, start_key_len), &a) : nullptr),
+      (limit_key ? (b = Slice(limit_key, limit_key_len), &b) : nullptr));
+}
+\`\`\`
+
+**If you have options, also add:**
+
+\`\`\`cpp
+// Options struct wrapper
+struct rocksdb_your_api_options_t {
+  YourAPIOptions rep;
+};
+
+rocksdb_your_api_options_t* rocksdb_your_api_options_create() {
+  return new rocksdb_your_api_options_t;
+}
+
+void rocksdb_your_api_options_destroy(rocksdb_your_api_options_t* opt) {
+  delete opt;
+}
+
+void rocksdb_your_api_options_set_some_option(
+    rocksdb_your_api_options_t* opt, unsigned char value) {
+  opt->rep.some_boolean_option = value;
+}
+\`\`\`
+
+### Step 6: Add Java Bindings
+
+**Java API:** `java/src/main/java/org/rocksdb/RocksDB.java`
+
+\`\`\`java
+// Basic version
+public void yourNewAPI() throws RocksDBException {
+  yourNewAPI(null);
+}
+
+// Column family version
+public void yourNewAPI(ColumnFamilyHandle columnFamilyHandle)
+    throws RocksDBException {
+  yourNewAPI(nativeHandle_, null, -1, null, -1, 0,
+      columnFamilyHandle == null ? 0 : columnFamilyHandle.nativeHandle_);
+}
+
+// Range version
+public void yourNewAPI(final byte[] begin, final byte[] end)
+    throws RocksDBException {
+  yourNewAPI(null, begin, end);
+}
+
+// Full-featured version with options
+public void yourNewAPI(ColumnFamilyHandle columnFamilyHandle,
+                       final byte[] begin, final byte[] end,
+                       final YourAPIOptions options)
+    throws RocksDBException {
+  yourNewAPI(nativeHandle_,
+      begin, begin == null ? -1 : begin.length,
+      end, end == null ? -1 : end.length,
+      options.nativeHandle_,
+      columnFamilyHandle == null ? 0 : columnFamilyHandle.nativeHandle_);
+}
+
+// Native method declaration
+private static native void yourNewAPI(final long handle,
+    /* @Nullable */ final byte[] begin, final int beginLen,
+    /* @Nullable */ final byte[] end, final int endLen,
+    final long optionsHandle,
+    final long cfHandle);
+\`\`\`
+
+**Options Class:** `java/src/main/java/org/rocksdb/YourAPIOptions.java`
+
+\`\`\`java
+public class YourAPIOptions extends RocksObject {
+
+  public YourAPIOptions() {
+    super(newYourAPIOptions());
+  }
+
+  // Builder pattern setters
+  public YourAPIOptions setSomeBooleanOption(boolean value) {
+    setSomeBooleanOption(nativeHandle_, value);
+    return this;
+  }
+
+  // Getters
+  public boolean someBooleanOption() {
+    return someBooleanOption(nativeHandle_);
+  }
+
+  // Native method declarations
+  private static native long newYourAPIOptions();
+  private static native void disposeInternalJni(long handle);
+  private static native void setSomeBooleanOption(long handle, boolean value);
+  private static native boolean someBooleanOption(long handle);
+
+  @Override
+  protected final void disposeInternal(final long handle) {
+    disposeInternalJni(handle);
+  }
+}
+\`\`\`
+
+**JNI Implementation:** `java/rocksjni/rocksjni.cc`
+
+\`\`\`cpp
+void Java_org_rocksdb_RocksDB_yourNewAPI(
+    JNIEnv* env, jclass,
+    jlong jdb_handle, jbyteArray jbegin, jint jbegin_len,
+    jbyteArray jend, jint jend_len,
+    jlong joptions_handle, jlong jcf_handle) {
+
+  // 1. Convert Java byte arrays to C++ strings
+  jboolean has_exception = JNI_FALSE;
+  std::string str_begin;
+  if (jbegin_len > 0) {
+    str_begin = ROCKSDB_NAMESPACE::JniUtil::byteString<std::string>(
+        env, jbegin, jbegin_len,
+        [](const char* str, const size_t len) { return std::string(str, len); },
+        &has_exception);
+    if (has_exception == JNI_TRUE) return;
+  }
+
+  std::string str_end;
+  if (jend_len > 0) {
+    str_end = ROCKSDB_NAMESPACE::JniUtil::byteString<std::string>(
+        env, jend, jend_len,
+        [](const char* str, const size_t len) { return std::string(str, len); },
+        &has_exception);
+    if (has_exception == JNI_TRUE) return;
+  }
+
+  // 2. Get or create options
+  ROCKSDB_NAMESPACE::YourAPIOptions* options = nullptr;
+  if (joptions_handle == 0) {
+    options = new ROCKSDB_NAMESPACE::YourAPIOptions();
+  } else {
+    options = reinterpret_cast<ROCKSDB_NAMESPACE::YourAPIOptions*>(joptions_handle);
+  }
+
+  // 3. Unwrap handles
+  auto* db = reinterpret_cast<ROCKSDB_NAMESPACE::DB*>(jdb_handle);
+  ROCKSDB_NAMESPACE::ColumnFamilyHandle* cf_handle =
+      jcf_handle == 0 ? db->DefaultColumnFamily()
+                      : reinterpret_cast<ROCKSDB_NAMESPACE::ColumnFamilyHandle*>(jcf_handle);
+
+  // 4. Create Slices
+  std::unique_ptr<ROCKSDB_NAMESPACE::Slice> begin;
+  std::unique_ptr<ROCKSDB_NAMESPACE::Slice> end;
+  if (jbegin_len > 0) begin.reset(new ROCKSDB_NAMESPACE::Slice(str_begin));
+  if (jend_len > 0) end.reset(new ROCKSDB_NAMESPACE::Slice(str_end));
+
+  // 5. Call C++ API
+  ROCKSDB_NAMESPACE::Status s = db->YourNewAPI(*options, cf_handle, begin.get(), end.get());
+
+  // 6. Cleanup if we created options
+  if (joptions_handle == 0) delete options;
+
+  // 7. Throw Java exception on error
+  ROCKSDB_NAMESPACE::RocksDBExceptionJni::ThrowNew(env, s);
+}
+\`\`\`
+
+**Options JNI:** `java/rocksjni/your_api_options.cc`
+
+\`\`\`cpp
+jlong Java_org_rocksdb_YourAPIOptions_newYourAPIOptions(JNIEnv*, jclass) {
+  auto* options = new ROCKSDB_NAMESPACE::YourAPIOptions();
+  return GET_CPLUSPLUS_POINTER(options);
+}
+
+void Java_org_rocksdb_YourAPIOptions_disposeInternalJni(JNIEnv*, jclass, jlong jhandle) {
+  auto* options = reinterpret_cast<ROCKSDB_NAMESPACE::YourAPIOptions*>(jhandle);
+  delete options;
+}
+
+void Java_org_rocksdb_YourAPIOptions_setSomeBooleanOption(
+    JNIEnv*, jclass, jlong jhandle, jboolean value) {
+  auto* options = reinterpret_cast<ROCKSDB_NAMESPACE::YourAPIOptions*>(jhandle);
+  options->some_boolean_option = static_cast<bool>(value);
+}
+
+jboolean Java_org_rocksdb_YourAPIOptions_someBooleanOption(JNIEnv*, jclass, jlong jhandle) {
+  auto* options = reinterpret_cast<ROCKSDB_NAMESPACE::YourAPIOptions*>(jhandle);
+  return static_cast<jboolean>(options->some_boolean_option);
+}
+\`\`\`
+
+### Step 7: Update Build Files
+
+**Java CMakeLists.txt:** `java/CMakeLists.txt`
+
+Add your new Java source files:
+\`\`\`cmake
+src/main/java/org/rocksdb/YourAPIOptions.java
+src/test/java/org/rocksdb/YourAPIOptionsTest.java
+\`\`\`
+
+### Step 8: Add Release Notes
+
+**Directory:** `unreleased_history/`
+
+RocksDB uses individual files in the `unreleased_history/` directory rather than directly editing `HISTORY.md`. This avoids merge conflicts and ensures changes are attributed to the correct release version.
+
+Add a file to the appropriate subdirectory:
+- `unreleased_history/new_features/` - For new functionality
+- `unreleased_history/public_api_changes/` - For API changes
+- `unreleased_history/behavior_changes/` - For behavior modifications
+- `unreleased_history/bug_fixes/` - For bug fixes
+
+**Example:** `unreleased_history/new_features/your_new_api.md`
+
+\`\`\`markdown
+Added `YourNewAPI()` to support [describe functionality]. See `YourAPIOptions` for configuration.
+\`\`\`
+
+**Example:** `unreleased_history/public_api_changes/your_api_options.md`
+
+**Note:** Files should contain one line of markdown. The "* " prefix is automatically added if not included. These files are compiled into `HISTORY.md` during the release process.
+
+### Step 9: Add Tests
+
+**C++ Unit Tests:** `db/db_your_api_test.cc` or add to existing test file
+
+\`\`\`cpp
+TEST_F(DBTest, YourNewAPIBasic) {
+  Options options = CurrentOptions();
+  CreateAndReopenWithCF({"pikachu"}, options);
+
+  // Setup test data
+  ASSERT_OK(Put(1, "key1", "value1"));
+  ASSERT_OK(Put(1, "key2", "value2"));
+
+  // Test your API
+  YourAPIOptions api_options;
+  api_options.some_boolean_option = true;
+  ASSERT_OK(db_->YourNewAPI(api_options, handles_[1], nullptr, nullptr));
+
+  // Verify results
+  // ...
+}
+\`\`\`
+
+**Java Tests:** `java/src/test/java/org/rocksdb/YourAPIOptionsTest.java`
+
+\`\`\`java
+public class YourAPIOptionsTest {
+  @Test
+  public void yourAPIOptions() {
+    try (final YourAPIOptions options = new YourAPIOptions()) {
+      assertFalse(options.someBooleanOption());
+      options.setSomeBooleanOption(true);
+      assertTrue(options.someBooleanOption());
+    }
+  }
+}
+\`\`\`
+
+## File Summary Checklist
+
+
+| Component | File(s) | Required |
+|-----------|---------|----------|
+| C++ Public Interface | `include/rocksdb/db.h` | ✓ |
+| Options Struct | `include/rocksdb/options.h` | If needed |
+| DBImpl Declaration | `db/db_impl/db_impl.h` | ✓ |
+| DBImpl Implementation | `db/db_impl/db_impl_*.cc` | ✓ |
+| StackableDB | `include/rocksdb/utilities/stackable_db.h` | ✓ |
+| Secondary DB | `db/db_impl/db_impl_secondary.h` | If not supported |
+| Compacted DB | `db/db_impl/compacted_db_impl.h` | If not supported |
+| C API Header | `include/rocksdb/c.h` | ✓ |
+| C API Implementation | `db/c.cc` | ✓ |
+| Java API | `java/src/main/java/org/rocksdb/RocksDB.java` | ✓ |
+| Java Options | `java/src/main/java/org/rocksdb/YourAPIOptions.java` | If needed |
+| JNI Implementation | `java/rocksjni/rocksjni.cc` | ✓ |
+| JNI Options | `java/rocksjni/your_api_options.cc` | If needed |
+| Java CMake | `java/CMakeLists.txt` | If new files |
+| Changelog | `unreleased_history/*.md` | ✓ |
+| C++ Tests | `db/db_*_test.cc` | ✓ |
+| Java Tests | `java/src/test/java/org/rocksdb/*Test.java` | ✓ |
+
+## Best Practices
+
+1. **Error Handling**: Always return `Status` objects in C++, throw exceptions in Java
+2. **Default Values**: Provide sensible defaults for all options
+3. **Documentation**: Add clear comments for all public methods and options
+4. **Column Family Support**: Always support column family operations
+5. **Thread Safety**: Document thread-safety guarantees
+6. **Backward Compatibility**: Avoid breaking existing API contracts
+7. **Testing**: Add comprehensive unit tests for all code paths

claude_md/ci_complexity_eval_prompt.md

@@ -0,0 +1,61 @@
+# PR Complexity Classifier — CI Triage Prompt
+
+## Purpose
+Quickly classify a RocksDB pull request as **simple** or **complex** so the
+downstream reviewer can pick an appropriate thinking budget.
+
+## Output Contract (STRICT)
+Your final response MUST be exactly one of these two lowercase tokens, on a
+line by itself, with no other text:
+
+```
+simple
+```
+
+or
+
+```
+complex
+```
+
+If you are unsure, output `complex`. The downstream review will use this token
+to set its thinking budget — when in doubt, prefer the more thorough budget.
+
+## Classification Heuristics
+
+Treat a PR as **simple** when ALL of the following hold:
+- Diff touches < ~200 lines of non-test code
+- No changes to public headers under `include/rocksdb/`
+- No changes to on-disk format (SST block layout, WAL record layout,
+  manifest, options file format, version edit encoding)
+- No changes to compaction picker, write-path locking, recovery, or
+  WAL/memtable lifecycle
+- No new public option, no new statistics counter, no new RPC/serialized
+  message
+- Tests-only or docs-only changes
+- Trivial refactors (rename, comment, dead-code removal, lint fixes)
+- One-line bug fix with obvious root cause and a focused regression test
+
+Treat a PR as **complex** when ANY of the following hold:
+- Touches files in `db/`, `db/compaction/`, `db/blob/`, `cache/`,
+  `table/block_based/`, `file/`, `env/io_*` with > ~50 lines of logic change
+- Modifies thread-safety/synchronization (mutexes, atomics, memory ordering,
+  refcounting, condvars)
+- Changes serialization or on-disk format
+- Changes public API surface in `include/rocksdb/`
+- Adds a new feature flag, option, or compaction style
+- Touches transactions (`utilities/transactions/`), backup/checkpoint,
+  user-defined timestamps, or remote compaction
+- Cross-cutting refactor spanning > 5 directories
+
+## How To Decide
+1. Read the diff summary and changed-file list provided below.
+2. Skim the diff hunks — focus on which subsystems are touched and whether
+   the change is mechanical vs. semantic.
+3. Apply the heuristics above. Default to `complex` if the rules conflict.
+4. Output the single token. No preamble. No explanation.
+
+## Tool Use
+You may use `View`, `GlobTool`, and `GrepTool` to peek at one or two files
+if the diff snippet alone is ambiguous, but keep this fast — this is a
+triage step, not a review. Do NOT spawn sub-agents.

claude_md/ci_query_prompt.md

@@ -0,0 +1,3 @@
+You are an expert C++ engineer for RocksDB.
+Read CLAUDE.md in the repo root and claude_md/ files for project context.
+Answer thoroughly with exact file paths and line numbers.

claude_md/ci_recovery_prompt.md

@@ -0,0 +1,54 @@
+Read review-findings.md. This file contains partial code review findings
+from a session that ran out of turns before finishing. Reformat them into
+a clean final review comment.
+
+## Required Output Structure
+
+Use this exact structure so the PR page stays scrollable:
+
+```markdown
+## Summary
+
+> **Partial review** — the analysis was interrupted before all perspectives
+> were completed. Findings below cover only the perspectives that finished.
+> You can request a fresh full review with `/claude-review`.
+
+<!-- One or two sentences of overall assessment. -->
+
+**High-severity findings (N):**
+- **[file.cc:123]** One-line description. <!-- repeat per HIGH finding -->
+
+<!-- If no HIGH findings were salvaged, write: -->
+<!-- _No high-severity findings recovered._ -->
+
+<details>
+<summary>Recovered findings (click to expand)</summary>
+
+### Findings
+
+#### :red_circle: HIGH
+... (H1, H2, ...)
+
+#### :yellow_circle: MEDIUM
+... (M1, M2, ...)
+
+#### :green_circle: LOW / NIT
+... (L1, L2, ...)
+
+### Cross-Component Analysis
+<!-- Whatever cross-component results were captured. -->
+
+### Positive Observations
+<!-- Optional. -->
+
+</details>
+```
+
+## Rules
+- The `## Summary`, the partial-review notice, and the HIGH bullet list MUST
+  stay outside the `<details>` block.
+- All per-finding detail and analysis MUST live inside the `<details>` block.
+- Do NOT nest `<details>` blocks.
+- Do NOT add any text after the closing `</details>` — the comment-builder
+  appends its own footer.
+- Output ONLY the formatted review. No commentary, no explanation.

claude_md/ci_review_prompt.md

@@ -0,0 +1,661 @@
+# Code Review Workflow — CI Prompt
+
+## Purpose
+Thorough multi-agent code review for RocksDB commits following CLAUDE.md guidelines,
+with structured codebase exploration, inter-agent debate, and verification.
+
+IMPORTANT — Incremental output: After completing EACH major phase (Setup,
+Codebase Context, Initial Review, Debate, Synthesis), append your findings
+to review-findings.md using the Write tool. This ensures partial results are
+saved even if the review is interrupted by the turn limit. After the final
+synthesis, write the complete review to review-findings.md, replacing
+previous content. Also output the final review as your response text.
+
+## Workflow Steps
+
+### 1. Setup Phase
+- Read CLAUDE.md to understand review guidelines
+- Identify the commit/diff/PR to review
+- The PR diff is provided below in this prompt. The repository is already
+  checked out — use local file search tools (Grep, Glob, Read) to explore.
+- Parse the changed files and categorize them (API, core logic, tests, etc.)
+- Read all changed files to build full context
+
+### 2. Codebase Context Phase (CRITICAL — Do Not Skip)
+
+**Why this matters**: Review agents that only see the diff miss systemic bugs.
+For example, a change to an iterator's return value might look correct in
+isolation but break multi-SST iteration 5 layers up the call stack. A change
+to error handling might silently drop errors that a caller 3 levels up relies
+on for recovery. This phase builds the context that prevents those blind spots.
+
+Go deep. Surface-level reading leads to reviews that miss caching layers,
+existing helper functions, or concurrency requirements. The most expensive
+failure mode is findings that look correct in isolation but miss how the
+change breaks the surrounding system.
+
+The team lead spawns one or more research agents to perform the following
+analyses using local file search tools (Grep, Glob, Read). The research
+must be written to `context.md` BEFORE any review agent is spawned.
+
+#### 2a. Subsystem Deep-Read
+Read the changed files AND their surrounding subsystem **in depth** — not just
+signatures, but actual logic, edge cases, data flows, locking protocols,
+concurrency patterns, and interactions between components.
+
+For each changed file, also read:
+- The header that declares its interface (if the change is in a .cc file)
+- The sibling implementation that does the same thing the "standard" way
+  (e.g., for a UDI iterator change, read how `IndexBlockIter` handles the
+  same scenario — it's the reference implementation)
+- The wrapper/adapter layer that sits between this code and its callers
+- Any existing tests to understand what behaviors are currently guaranteed
+
+#### 2b. Caller-Chain Analysis (upstream impact)
+For each changed function/method, trace the call chain UPWARD 3-5 levels to
+understand who consumes the changed behavior and what invariants they rely on.
+**Focus on control flow decisions** — if/else branches, while loop conditions,
+early returns — that depend on the changed return values or state.
+
+**How to do this**:
+- Search for callers of each changed function (search for the function name, the
+  class method, virtual overrides)
+- For each caller, search for ITS callers, repeating 3-5 levels up
+- At each level, read the actual code to understand the control flow decision
+- Stop when you reach a "terminal" caller (e.g., user-facing API, top-level
+  iterator) or when the propagation is clearly safe
+
+#### 2c. Callee-Chain Analysis (downstream dependencies AND side effects)
+For each changed function, trace what it calls and whether those calls have
+new preconditions or changed semantics. **Critically, trace SIDE EFFECTS —
+not just return values.** Many bugs hide in side effects on shared state
+(counters, sequence numbers, flags) that are invisible if you only check
+return values.
+
+**For each callee, ask:**
+1. What does it RETURN? (the obvious check)
+2. What shared state does it MUTATE? (the non-obvious check)
+3. Under what PRECONDITIONS does it operate correctly?
+4. Are those preconditions met in the new calling context?
+
+#### 2d. Sibling Implementation Comparison
+Identify the "reference" or "standard" implementation that does the same thing
+the changed code does, and compare their behavior. This is critical for plugin/
+extension APIs where the implementation must match an implicit contract.
+
+#### 2e. Invariant Documentation
+Document the key invariants that the changed code must maintain. Read existing
+comments, assertions, and test expectations to discover these invariants.
+
+#### 2f. Related Functionality and Existing Conventions
+Identify related functionality that already exists in the codebase:
+- Are there existing helper functions the change should use (or is duplicating)?
+- Are there existing patterns for the same kind of change (e.g., how other
+  Customizable subclasses handle deprecation)?
+- Are there existing tests that test similar scenarios (e.g., multi-SST
+  iteration tests that could be extended)?
+
+#### 2g. Cross-Component Data Consumer Analysis (CRITICAL — common blind spot)
+
+**Why this is separate from caller-chain analysis:** Sections 2b-2c trace
+who CALLS the changed functions. This section traces who CONSUMES the data
+that the changed code PRODUCES. These are often completely different
+subsystems.
+
+When the change writes data to a shared structure (memtable, SST block, cache
+entry, statistics counter), ask: **"Who reads this data, under what rules,
+and do those rules match the writer's assumptions?"**
+
+**How to do this:**
+1. Identify every piece of data the change WRITES (e.g., a range tombstone
+   entry, a counter update, a metadata field)
+2. For each, search the codebase for ALL readers of that data structure
+3. For each reader, check:
+   - Does the reader apply visibility rules (seqno, read_callback, snapshot)?
+   - Are those rules compatible with the writer's assumptions?
+   - Does the reader assume invariants about the data (e.g., seqno ordering,
+     monotonicity) that the writer might violate?
+
+#### 2h. Alternative Execution Contexts
+
+The same code path may run in different contexts with different assumptions.
+**Enumerate all contexts and check each one.** This is where "works in the
+common case but breaks in edge configurations" bugs hide.
+
+For RocksDB, always check whether the changed code interacts differently with:
+
+| Context | Key difference | Common failure mode |
+|---------|---------------|-------------------|
+| WritePreparedTxnDB / WriteUnpreparedTxnDB | `read_callback_` controls visibility, not just seqno | Visibility bypass |
+| ReadOnly DB / SecondaryInstance | No mutable memtable, writes not allowed | Null pointer or no-op needed |
+| CompactionService / Remote compaction | Different process, serialized state | Serialization mismatch |
+| User-defined timestamps | Extra dimension in key comparison and visibility | Wrong ordering |
+| MemPurge | Memtable-to-memtable, not memtable-to-SST | Missing data |
+| Column family with BlobDB | Values may be in blob files, not inline | Missing dereference |
+| Snapshots (old, held long-term) | Snapshot seqno may be far behind current state | Metadata corruption |
+| Concurrent writers (allow_concurrent_memtable_write) | Lock-free paths vs locked paths | Lost updates |
+| FIFO / Universal compaction | Different compaction invariants than Level | Wrong assumptions |
+| Prefix seek / total order seek | Different iterator behavior | Wrong iteration results |
+
+**For each context, ask:**
+1. Does the code execute in this context? (Check constructor, feature flags)
+2. If yes, do the assumptions still hold?
+3. If not, should the feature be disabled in this context?
+
+#### 2i. Assumption Stress-Testing (the "logically X" audit)
+
+When the change claims a property (e.g., "logically redundant," "no-op in
+this case," "safe because X"), **systematically break it:**
+
+1. **State the claim precisely.** E.g., "The inserted range tombstone is
+   logically redundant — it covers only keys already deleted by point
+   tombstones."
+2. **List the preconditions** that must be true for the claim to hold.
+3. **For each precondition, construct a counterexample** — a concrete scenario
+   where the precondition is violated.
+4. **Verify each counterexample against the code.** Does the code guard
+   against it? If not, it's a bug.
+
+**Anti-pattern: treating asserts as proofs.** When you see an assert, do NOT
+conclude "the invariant holds." Instead ask: "Can I construct an input where
+this assert fires?" If yes, it's a bug (the assert catches it in debug but
+release builds silently corrupt). If you cannot construct a counterexample
+after trying, document WHY it's impossible.
+
+#### 2j. Write Context Document
+Write the complete analysis to `context.md` in the review folder. This document
+is provided to ALL review agents as part of their prompt.
+
+**Context document template**:
+```markdown
+# Codebase Context for Review
+
+## How the Relevant Subsystem Works Today
+[Detailed description of the subsystem architecture, data flows,
+and component interactions. Not just "what" but "how" and "why."]
+
+## Changed Functions and Their Call Chains
+
+### function_name() (file:line)
+**What changed**: [brief description of the behavioral change]
+
+**Upstream callers** (who depends on this):
+1. CallerA::method() (file:line) — uses return value to decide X
+2. CallerB::method() (file:line) — passes result to CallerC
+3. CallerC::method() (file:line) — THE CRITICAL DECISION POINT: ...
+
+**Downstream callees** (what this depends on):
+1. calleeA() — behavior unchanged
+2. calleeB() — NEW dependency, requires X
+
+**Sibling implementation** (how the "standard" version handles this):
+- StandardImpl::method() does Y at file:line, which ensures invariant Z
+- The changed code must match or document any deviation
+
+**Key invariants**:
+- Must never return X when Y is true because CallerC will...
+- Must always set Z before returning because CallerB assumes...
+
+## System Architecture Context
+[How the changed components fit into the overall system]
+
+## Known Invariants That Must Be Preserved
+1. ...
+2. ...
+
+## Existing Conventions and Related Code
+- [helper functions, patterns, existing tests that are relevant]
+
+## Cross-Component Data Consumers
+For each piece of data the change WRITES to a shared structure:
+### [data item] written to [structure]
+**Writer assumptions**: [what the writer assumes about how this data is consumed]
+**All readers**:
+1. ReaderA::method() (file:line) — reads under [visibility rules]
+   - Compatible with writer? YES/NO. If NO, explain the mismatch.
+2. ReaderB::method() (file:line) — reads under [different rules]
+   - Compatible with writer? YES/NO.
+
+## Alternative Execution Contexts
+| Context | Does code execute? | Assumptions hold? | Action needed? |
+|---------|-------------------|-------------------|----------------|
+| WritePreparedTxnDB | YES/NO | YES/NO | [disable/guard/safe] |
+| Old snapshots | YES/NO | YES/NO | ... |
+| User-defined timestamps | YES/NO | YES/NO | ... |
+| ReadOnly DB | YES/NO | YES/NO | ... |
+| ... | ... | ... | ... |
+
+## Assumption Stress Test
+### Claim: "[the design claim, e.g., logically redundant]"
+**Preconditions for claim to hold:**
+1. [precondition] — counterexample: [scenario]. Guarded? YES/NO.
+2. [precondition] — counterexample: [scenario]. Guarded? YES/NO.
+
+## Potential Pitfalls
+- [specific scenarios where the change could interact badly with
+  the surrounding system, identified from the caller-chain analysis]
+```
+
+### 3. Initial Review Phase (Parallel)
+Create a team and spawn 5 review agents in parallel. **Include the context
+document from Phase 2 in each agent's prompt.** Each agent writes findings
+to its own file and sends a summary message to the team lead.
+
+Each agent's prompt should include:
+```
+## Codebase Context (READ THIS FIRST)
+[paste or reference the context.md file]
+
+You MUST consider how your findings interact with the upstream callers
+and system invariants documented above. A finding that looks correct
+in isolation may be a critical bug when you consider the full call chain.
+```
+
+#### Agent: Design & Approach Reviewer
+- Read the commit message deeply to understand the problem being solved
+- Analyze whether this is the right approach to the problem
+- Consider alternative designs and trade-offs:
+  - Are there simpler solutions that achieve the same goal?
+  - Does the approach introduce unnecessary complexity?
+  - Would a different data structure or algorithm be more appropriate?
+- Evaluate whether the change follows existing architectural patterns or
+  introduces new patterns that may be inconsistent
+- Assess the scope: is the change too large? Should it be split into
+  smaller, independently reviewable pieces?
+- Check if the approach has precedent in the codebase or in the academic
+  literature it references (e.g., SuRF paper)
+
+#### Agent: Correctness Reviewer
+- Thread safety and concurrency analysis
+- Error handling and propagation via Status type
+- Edge cases (empty inputs, overflow, boundary conditions)
+- Data corruption scenarios
+- Logic correctness of new algorithms
+- **Behavioral contract changes**: Do return value semantics match what
+  upstream callers expect? (Use the caller-chain analysis from context.md)
+- **Callee side effects**: Does the change call functions that mutate shared
+  state (counters, seqnos, metadata)? Are the mutations correct for the new
+  calling context? (Use the callee-chain analysis from context.md)
+
+#### Agent: Cross-Component & Adversarial Reviewer
+
+This agent exists because the most critical bugs hide at component boundaries,
+not within a single component. It uses a fundamentally different methodology
+than the correctness reviewer: instead of verifying "does the code do what it
+intends?", it asks "what breaks when we change the assumptions?"
+
+**Data-flow analysis:** Perform the cross-component data consumer analysis
+described in section 2g. For every piece of data the change WRITES to a shared
+structure, trace ALL READERS and verify their visibility rules are compatible
+with the writer's assumptions. This is a DATA-FLOW question, not a
+CONTROL-FLOW question — readers may be in completely different subsystems.
+
+**Alternative execution contexts:** Use the canonical table from section 2h.
+Enumerate all contexts where the changed code executes and verify assumptions
+hold in each.
+
+**Assumption stress-testing and assert-breaking:** Follow the methodology from
+section 2i. Identify every design claim, enumerate preconditions, construct
+counterexamples. Treat asserts as hypotheses to break, not proofs.
+**Red flag words**: "logically redundant", "safe because", "no-op",
+"always true", "cannot happen", "invariant holds"
+
+**Callee side-effect audit:** Perform the callee side-effect audit described
+in section 2c. For every callee, ask what it RETURNS and what it MUTATES.
+
+Write findings to `findings-cross-component.md`.
+
+#### Agent: Invariant Adversary
+
+This agent does NOT read the diff in detail. It takes the feature summary and
+systematically tries to break it. While other agents verify "does the code do
+what it says?", this agent asks "what existing system invariants does this
+feature violate?" and "under what inputs do the design claims fail?"
+
+**Steps 1-4: Assumption stress-testing.** Follow the methodology from section
+2i: extract design claims, enumerate preconditions, construct counterexamples,
+and attempt to break every assert. Be exhaustive about input parameter ranges,
+shared state configurations, and concurrent interleaving.
+
+**Step 5: Callee side-effect audit.** Perform the callee side-effect audit
+described in section 2c. For every function the changed code calls, list ALL
+mutations to shared state (atomic CAS loops, counter increments, flag/metadata
+updates, cache invalidation). A function returning `Status::OK()` does NOT
+mean its side effects are correct.
+
+Write findings to `findings-invariant-adversary.md`.
+
+#### Agent: Caller-Context Auditor
+
+This agent traces BACKWARD from every entry point the changed code hooks into.
+While other agents read the changed code forward ("what does it do?"), this
+agent enumerates WHO invokes it and WITH WHAT parameter ranges.
+
+The key insight: a function that is correct for all *typical* inputs may be
+catastrophically wrong for *atypical-but-reachable* inputs. This agent's job
+is to find the atypical inputs.
+
+**Step 1: Identify entry points.** List every function/constructor/method in
+the changed code that receives external input (parameters, config values,
+pointers to shared state). Include:
+- Constructor parameters (e.g., `active_mem`, `read_callback`, `sequence`)
+- Virtual method overrides that callers invoke polymorphically
+- Functions called from multiple subsystems
+
+**Step 2: Enumerate all callers (3-5 levels up).** For each entry point,
+search the codebase for ALL callers. Do NOT stop at the first caller — trace
+the full call chain. Use `Grep` and `Glob` to find:
+- Direct callers of the function
+- Callers of wrapper/adapter functions that forward to it
+- Factory functions that construct the object
+- Virtual dispatch sites (search for the base class method name)
+
+**Step 3: Parameter range analysis.** For each caller, determine:
+- What values does it pass for each parameter?
+- Under what conditions does it call this function?
+- Are there callers that pass unusual values? (e.g., `kMaxSequenceNumber`,
+  `nullptr`, old snapshot seqnos, non-null `read_callback_`)
+
+Build a parameter range table for each entry point, listing all callers
+and the values they pass for each parameter.
+
+**Step 4: Configuration matrix.** Enumerate option/config combinations that
+affect the changed code path:
+- Which options enable/disable the feature?
+- Which options change the execution context? (e.g.,
+  `allow_concurrent_memtable_write`, `use_trie_index`)
+- Are there option combinations that create contradictions?
+
+**Step 5: Cross-reference with context.md.** Compare your caller analysis
+with the invariants and execution contexts documented in context.md. Flag
+any caller that violates an assumed precondition.
+
+Write findings to `findings-caller-audit.md`.
+
+#### Agent: Performance Reviewer
+- Memory allocation on hot paths
+- Unnecessary copies (string, buffer)
+- Cache efficiency and data locality
+- Loop optimization opportunities
+- Branch prediction (LIKELY/UNLIKELY)
+- Zero-overhead design verification
+
+#### Agent: API & Compatibility Reviewer
+- Public API backwards compatibility
+- API consistency with existing patterns
+- Documentation completeness
+- Deprecation policy compliance
+- Forward compatibility (struct extensibility)
+- **Behavioral compatibility**: Do changed semantics (e.g., kOutOfBound vs
+  kUnknown) break implicit contracts with callers?
+
+#### Agent: Serialization & Deserialization Reviewer
+- Format correctness and versioning
+- Alignment requirements
+- Integer overflow in size computations
+- Bounds checking on untrusted data
+- Crafted input attack vectors
+
+#### Agent: Test Coverage Reviewer
+- Edge case coverage
+- Failure mode testing (corruption, truncation)
+- Round-trip testing (build → serialize → deserialize → verify)
+- Integration test coverage
+- **System-level test coverage**: Are the caller-chain interactions tested?
+  (e.g., multi-SST iteration with UDI, level compaction with new behavior)
+- Test quality (no flaky patterns, good assertions)
+
+### 4. Round-Robin Debate Phase
+After all 5 agents complete their initial review, the team lead orchestrates
+a structured debate:
+
+#### Step 4a: Share findings
+- Team lead sends each agent a summary of ALL other agents' findings
+  (or instructs each agent to read the other agents' findings files)
+
+#### Step 4b: Critique round (2 rounds)
+Each agent reviews the findings from the other agents and sends messages to
+challenge, support, or refine them:
+
+- **Challenge**: "I disagree with [agent] [finding] because [evidence]."
+- **Support**: "I independently found the same issue — this confirms it."
+- **Refine**: "[Finding A] is actually a consequence of [Finding B].
+  The root cause is the same."
+
+The debate assignment follows a round-robin pattern:
+```
+correctness-reviewer      →  critiques  →  invariant-adversary, serialization
+cross-component-reviewer  →  critiques  →  correctness, caller-audit
+invariant-adversary       →  critiques  →  correctness, cross-component
+caller-audit              →  critiques  →  invariant-adversary, cross-component
+performance-reviewer      →  critiques  →  api, cross-component
+api-reviewer              →  critiques  →  correctness, performance
+serialization-reviewer    →  critiques  →  correctness, invariant-adversary
+test-reviewer             →  critiques  →  serialization, caller-audit
+design-reviewer           →  critiques  →  cross-component, invariant-adversary
+```
+
+**Note:** The invariant-adversary and caller-audit agents are deliberately
+cross-linked with correctness and cross-component because their findings
+often reveal the same underlying bug from different angles (invariant
+violation vs reachable bad input vs data-flow mismatch).
+
+Each agent should:
+1. Read the assigned agents' findings files
+2. Send a critique message to each assigned agent
+3. Respond to critiques received from other agents
+4. Update their own findings file with any revisions (upgraded/downgraded severity,
+   withdrawn findings, new findings inspired by others)
+
+#### Step 4c: Team lead collects debate results
+- Read all updated findings files
+- Review the debate messages
+- Build consensus: findings supported by 2+ agents → HIGH confidence
+- Write consensus document with final severity classifications
+
+### 5. Consensus Phase
+Team lead synthesizes the debate into a consensus document:
+- Cross-reference overlapping findings across agents
+- Count agreement (majority = 2+ agents independently flagging or supporting)
+- Note disagreements and how they were resolved
+- Classify findings as HIGH/MEDIUM/LOW severity
+- Write consensus document
+
+### 6. Summary Phase
+- Compile all validated findings ordered by severity
+- Include detailed bug analysis (root cause, vulnerable code paths)
+- Include suggested fixes
+- Note which findings were debated and the outcome
+- Write the complete review to review-findings.md and output as response
+
+**Final report quality rules:**
+- The final report must be CLEAN and POLISHED. No stream-of-consciousness,
+  no "Wait, actually...", no "on closer re-examination". Those belong in
+  the working notes, not the output.
+- If a finding was raised during review but later disproven during debate
+  or deeper analysis, REMOVE IT entirely from the final report. Do not
+  include it with a retraction — just drop it.
+- If a finding was downgraded (e.g., Critical → Suggestion), present it
+  at the final severity only. Do not narrate the severity change.
+- Each finding in the final report should read as a confident, verified
+  conclusion — not a record of the analysis process.
+- The reader should never see the reviewer arguing with itself.
+
+**REQUIRED output structure (so the PR page stays scrollable):**
+
+The final response (and contents of `review-findings.md`) MUST follow this
+exact structure. The summary appears first so reviewers can see HIGH findings
+at a glance; everything else is hidden behind a `<details>` block.
+
+```markdown
+## Summary
+
+<!-- One or two sentences of overall assessment. -->
+
+**High-severity findings (N):**
+- **[file.cc:123]** One-line description of the issue. <!-- repeat per HIGH finding -->
+
+<!-- If there are NO high-severity findings, write exactly: -->
+<!-- _No high-severity findings._ -->
+
+<details>
+<summary>Full review (click to expand)</summary>
+
+### Findings
+
+#### :red_circle: HIGH
+
+##### H1. <Title> — `file.cc:123`
+- **Issue:** ...
+- **Root cause:** ...
+- **Suggested fix:** ...
+
+#### :yellow_circle: MEDIUM
+... (same structure: M1, M2, ...)
+
+#### :green_circle: LOW / NIT
+... (same structure: L1, L2, ...)
+
+### Cross-Component Analysis
+<!-- Execution-context table and assumption stress-test results. -->
+
+### Positive Observations
+<!-- Optional: good patterns, clever optimizations. -->
+
+</details>
+```
+
+Rules for this structure:
+- The top-level `## Summary` and the bullet list of HIGH findings MUST stay
+  outside the `<details>` block — they are always visible.
+- Every detail (per-finding root cause, fix, debate outcomes, cross-component
+  analysis, positive observations) MUST live inside the `<details>` block.
+- Do NOT nest a `<details>` inside another `<details>`.
+- Do NOT add any text after the closing `</details>` — the comment-builder
+  appends its own footer.
+- If the review is partial (recovery path), still produce the summary block
+  first, and put whatever was salvaged inside the `<details>` block.
+
+## Review Checklist
+
+### Context Phase (must be completed before agents spawn)
+- [ ] Subsystem deep-read — read changed files AND surrounding subsystem
+      in depth (logic, edge cases, data flows, locking, concurrency)
+- [ ] Caller chain for every changed public/virtual method (3-5 levels up)
+- [ ] Critical decision points where callers branch on changed behavior
+- [ ] Callee chain with SIDE EFFECTS — downstream dependencies, new
+      preconditions, AND mutations to shared state (section 2c)
+- [ ] Sibling implementations — how does the standard version handle same scenarios?
+- [ ] Invariants that callers rely on
+- [ ] Related functionality — existing helpers, patterns, conventions
+- [ ] Cross-component data consumers — for every data WRITTEN, find ALL readers
+      and verify visibility rules match (section 2g)
+- [ ] Alternative execution contexts verified (section 2h table)
+- [ ] Assumption stress-test — for every design claim, list preconditions
+      and construct counterexamples (section 2i)
+- [ ] Multi-component interactions (compaction, recovery, snapshots, iterators)
+- [ ] Configuration dependencies and unexpected option combinations
+- [ ] Potential pitfalls from caller-chain analysis
+
+### Review Phase (verified by agents)
+- [ ] Database semantics preserved (snapshot isolation, key ordering)
+- [ ] All error cases handled
+- [ ] Thread-safe with correct synchronization
+- [ ] No data races or deadlocks
+- [ ] Appropriate test coverage (edge cases, failure modes, system-level)
+- [ ] No unnecessary allocations or copies in hot paths
+- [ ] Backwards compatible
+- [ ] New APIs consistent with existing patterns and documented
+- [ ] Code follows RocksDB style conventions
+- [ ] Behavioral contracts with upstream callers preserved
+- [ ] All callers enumerated with parameter range table
+
+## Output Structure
+Write all review artifacts to the working directory root:
+- `review-findings.md` — Incremental findings (appended after each phase),
+  then replaced with the final synthesized review at the end
+- `context.md` — Codebase context (call chains, invariants)
+- `findings-*.md` — Per-agent findings (design, correctness, cross-component,
+  invariant-adversary, caller-audit, performance, api, serialization, tests)
+- `consensus.md` — Cross-review consensus (post-debate)
+
+
+
+## Team Structure
+```
+Team Lead (you)
+│
+├── Phase 2: Codebase Context (team lead or dedicated research agent)
+│   └── context-researcher    (general-purpose agent)
+│       ├── Trace caller chains (3-5 levels up)
+│       ├── Trace callee chains (dependencies AND side effects)
+│       ├── Trace data consumers (who reads what the change writes?)
+│       └── Document invariants
+│
+├── Phase 3: Initial Review (parallel, run_in_background)
+│   │  (all agents receive context.md in their prompt)
+│   ├── design-reviewer            (general-purpose agent)
+│   ├── correctness-reviewer       (general-purpose agent)
+│   ├── cross-component-reviewer   (general-purpose agent)
+│   ├── invariant-adversary        (general-purpose agent)  ← NEW
+│   ├── caller-audit               (general-purpose agent)  ← NEW
+│   ├── performance-reviewer       (general-purpose agent)
+│   ├── api-reviewer               (general-purpose agent)
+│   ├── serialization-reviewer     (general-purpose agent)
+│   └── test-reviewer              (general-purpose agent)
+│
+├── Phase 4: Debate (agents message each other)
+│   ├── correctness ↔ invariant-adversary, serialization
+│   ├── cross-component ↔ correctness, caller-audit
+│   ├── invariant-adversary ↔ correctness, cross-component
+│   ├── caller-audit ↔ invariant-adversary, cross-component
+│   ├── performance ↔ api, cross-component
+│   ├── api ↔ correctness, performance
+│   ├── serialization ↔ correctness, invariant-adversary
+│   ├── test-coverage ↔ serialization, caller-audit
+│   └── design ↔ cross-component, invariant-adversary
+│
+```
+
+
+## Agent Communication Protocol
+
+### During Initial Review (Phase 3)
+- Each agent writes findings to its own file
+- Each agent sends a summary message to team lead when done
+- Agents do NOT communicate with each other yet
+
+### During Debate (Phase 4)
+- Team lead sends each agent a message with instructions to:
+  1. Read the assigned agents' findings files
+  2. Send critique messages to those agents
+  3. Respond to incoming critiques
+  4. Update their own findings file with revisions
+- Each critique message should include:
+  - Which finding they're addressing (e.g., "Correctness F1")
+  - Whether they AGREE, DISAGREE, or want to REFINE
+  - Their reasoning with code evidence
+  - Suggested severity adjustment (if any)
+
+### Message format example
+```
+To: correctness-reviewer
+Re: Your Finding F1
+
+AGREE/DISAGREE/REFINE - [reasoning with code evidence].
+[Suggested severity adjustment if any.]
+```
+
+## Review Anti-Patterns
+
+These recurring failure modes lead to missed bugs. Each is detailed in the
+referenced section; this table is a quick-reference checklist.
+
+| Anti-Pattern | Fix | Reference |
+|---|---|---|
+| Return-Value Tunnel Vision | Trace callee MUTATIONS, not just returns | Section 2c |
+| Default-Configuration Bias | Enumerate all execution contexts | Section 2h |
+| Assert-as-Proof | Try to BREAK every assert | Section 2i |
+| Write-Path-Only Analysis | Trace data readers, not just writers | Section 2g |
+| Confirmation-Seeking Research | Use adversarial prompts ("find where X fails") | Invariant Adversary agent |
+| Data-Flow vs Control-Flow Confusion | Separate who CALLS from who READS the data | Section 2g |

claude_md/code_review.md

@@ -0,0 +1,104 @@
+# Code Review Skill
+
+This document defines the methodology for performing thorough, multi-perspective
+code reviews on RocksDB changes. It is used both by CI (GitHub Actions) and
+local review workflows.
+
+## Prerequisites
+
+Before starting a review:
+- Read `CLAUDE.md` in the repository root for project-specific guidelines
+- Read any files in `claude_md/` for architecture context
+- Identify the commit/diff/PR to review and parse the changed files
+
+## Review Methodology
+
+Conduct the review from multiple perspectives, then synthesize findings into a
+single report. Each perspective catches different classes of bugs.
+
+### Perspective 1: Codebase Context & Call-Chain Analysis
+
+Before reviewing the diff itself, build deep context:
+- For each changed function/method, trace the call chain UPWARD 3-5 levels.
+  Who consumes the changed behavior? What invariants do callers rely on?
+- Trace DOWNWARD into callees. What side effects do they have? What shared
+  state do they mutate (counters, sequence numbers, flags, metadata)?
+- Identify the "sibling" or "reference" implementation that handles the same
+  scenario the standard way. Compare behaviors.
+- For data written to shared structures (memtable, SST block, cache entry),
+  find ALL readers and verify their visibility rules match the writer.
+
+### Perspective 2: Correctness & Edge Cases
+
+- Thread safety and concurrency (lock ordering, data races)
+- Error handling and Status propagation
+- Edge cases: empty inputs, overflow, boundary conditions
+- Data corruption scenarios
+- Behavioral contract changes: do return value semantics match callers?
+
+### Perspective 3: Cross-Component & Adversarial Analysis
+
+Check the change in ALL execution contexts:
+
+| Context | Key difference |
+|---------|---------------|
+| WritePreparedTxnDB | read_callback_ controls visibility |
+| ReadOnly DB / SecondaryInstance | No mutable memtable |
+| CompactionService / Remote compaction | Different process |
+| User-defined timestamps | Extra key comparison dimension |
+| MemPurge | Memtable-to-memtable path |
+| BlobDB | Values in blob files, not inline |
+| Old snapshots | Seqno far behind current |
+| Concurrent writers | Lock-free vs locked paths |
+| FIFO / Universal compaction | Different invariants |
+| Prefix seek / total order seek | Different iterator behavior |
+
+When the change claims a property ("logically redundant", "safe because X"),
+systematically try to break it: list preconditions, construct counterexamples.
+
+### Perspective 4: Performance
+
+RocksDB is a high-performance storage engine.
+- Memory allocation on hot paths
+- Unnecessary copies (prefer move semantics, Slice, string_view)
+- Cache efficiency and data locality
+- Loop optimization, branch prediction (LIKELY/UNLIKELY)
+
+### Perspective 5: API, Compatibility & Testing
+
+- Public API backwards compatibility
+- Serialization format correctness and versioning
+- Test coverage for edge cases, failure modes, and system-level interactions
+
+## How to Explore the Codebase
+
+Use available tools to explore deeply — do NOT just review the diff in isolation.
+The most critical bugs hide at component boundaries.
+
+- Read the header files for changed implementations
+- Search for callers of changed functions (3-5 levels up)
+- Read existing tests to understand guaranteed behaviors
+- Check related implementations for conventions and patterns
+
+## Output Format
+
+### Summary
+Brief overall assessment (1-2 sentences).
+
+### Issues Found
+Categorize by severity:
+- :red_circle: **Critical**: Must fix (correctness, data corruption, security)
+- :yellow_circle: **Suggestion**: Should consider (performance, edge cases)
+- :green_circle: **Nitpick**: Minor style issues
+
+For each issue include:
+- File and line reference
+- Which review perspective found it
+- Description with root cause analysis
+- Suggested fix
+
+### Cross-Component Analysis
+Execution context checks and assumption stress-test results.
+
+### Positive Observations
+Good patterns, clever optimizations, or improvements.

claude_md/remove_option.md

@@ -0,0 +1,7 @@
+# Removing Deprecated Options from RocksDB
+### Keep in these files:
+- [ ] **KEEP** entry in type_info (`options/cf_options.cc` or `options/db_options.cc`) with `OptionVerificationType::kDeprecated` for loading old option files
+- [ ] **KEEP** or add test in `options/options_test.cc` `OptionsOldApiTest::GetOptionsFromMapTest` for loading old option files
+
+### Documentation:
+- [ ] Add release note to `HISTORY.md` and `unreleased_history/`

crash_test.mk

@@ -7,22 +7,41 @@ DB_STRESS_CMD?=./db_stress
 
 include common.mk
 
+ifdef COMPILE_WITH_TSAN
+	# Keep direct `make -f crash_test.mk COMPILE_WITH_TSAN=1 ...` runs
+	# aligned with the main Makefile's TSAN runtime options.
+	TSAN_OPTIONS?=suppressions=$(CURDIR)/tools/tsan_suppressions.txt
+	export TSAN_OPTIONS
+endif
+
 CRASHTEST_MAKE=$(MAKE) -f crash_test.mk
-CRASHTEST_PY=$(PYTHON) -u tools/db_crashtest.py --stress_cmd=$(DB_STRESS_CMD) --cleanup_cmd='$(DB_CLEANUP_CMD)'
+CRASHTEST_PY=$(PYTHON) -u tools/db_crashtest.py --stress_cmd=$(DB_STRESS_CMD) --cleanup_cmd='$(DB_CLEANUP_CMD)' --destroy_db_initially=1
 
 .PHONY: crash_test crash_test_with_atomic_flush crash_test_with_txn \
+	crash_test_with_wc_txn crash_test_with_wp_txn crash_test_with_wup_txn \
 	crash_test_with_best_efforts_recovery crash_test_with_ts \
+	crash_test_with_multiops_wc_txn \
+	crash_test_with_multiops_wp_txn \
+	crash_test_with_multiops_wup_txn \
+	crash_test_with_optimistic_txn \
+	crash_test_with_tiered_storage \
 	blackbox_crash_test blackbox_crash_test_with_atomic_flush \
+	blackbox_crash_test_with_wc_txn blackbox_crash_test_with_wp_txn \
+	blackbox_crash_test_with_wup_txn \
 	blackbox_crash_test_with_txn blackbox_crash_test_with_ts \
 	blackbox_crash_test_with_best_efforts_recovery \
-	whitebox_crash_test whitebox_crash_test_with_atomic_flush \
-	whitebox_crash_test_with_txn whitebox_crash_test_with_ts \
 	blackbox_crash_test_with_multiops_wc_txn \
 	blackbox_crash_test_with_multiops_wp_txn \
-	crash_test_with_tiered_storage blackbox_crash_test_with_tiered_storage \
-	whitebox_crash_test_with_tiered_storage \
-	whitebox_crash_test_with_optimistic_txn \
+	blackbox_crash_test_with_multiops_wup_txn \
 	blackbox_crash_test_with_optimistic_txn \
+	blackbox_crash_test_with_tiered_storage \
+	whitebox_crash_test whitebox_crash_test_with_atomic_flush \
+	whitebox_crash_test_with_wc_txn whitebox_crash_test_with_wp_txn \
+	whitebox_crash_test_with_wup_txn \
+	whitebox_crash_test_with_txn whitebox_crash_test_with_ts \
+	whitebox_crash_test_with_optimistic_txn \
+	whitebox_crash_test_with_tiered_storage \
+	crash_test_db_cleanup \
 
 crash_test: $(DB_STRESS_CMD)
 # Do not parallelize
@@ -34,10 +53,20 @@ crash_test_with_atomic_flush: $(DB_STRESS_CMD)
 	$(CRASHTEST_MAKE) whitebox_crash_test_with_atomic_flush
 	$(CRASHTEST_MAKE) blackbox_crash_test_with_atomic_flush
 
-crash_test_with_txn: $(DB_STRESS_CMD)
+crash_test_with_wc_txn: $(DB_STRESS_CMD)
 # Do not parallelize
-	$(CRASHTEST_MAKE) whitebox_crash_test_with_txn
-	$(CRASHTEST_MAKE) blackbox_crash_test_with_txn
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_wc_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_wc_txn
+
+crash_test_with_wp_txn: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_wp_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_wp_txn
+
+crash_test_with_wup_txn: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_wup_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_wup_txn
 
 crash_test_with_optimistic_txn: $(DB_STRESS_CMD)
 # Do not parallelize
@@ -62,6 +91,9 @@ crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
 crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
 	$(CRASHTEST_MAKE) blackbox_crash_test_with_multiops_wp_txn
 
+crash_test_with_multiops_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_multiops_wup_txn
+
 blackbox_crash_test: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --simple blackbox $(CRASH_TEST_EXT_ARGS)
 	$(CRASHTEST_PY) blackbox $(CRASH_TEST_EXT_ARGS)
@@ -69,8 +101,14 @@ blackbox_crash_test: $(DB_STRESS_CMD)
 blackbox_crash_test_with_atomic_flush: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --cf_consistency blackbox $(CRASH_TEST_EXT_ARGS)
 
-blackbox_crash_test_with_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --txn blackbox $(CRASH_TEST_EXT_ARGS)
+blackbox_crash_test_with_wc_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox --txn_write_policy 0 $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_wp_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox --txn_write_policy 1 $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox --txn_write_policy 2 $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_best_efforts_recovery: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --test_best_efforts_recovery blackbox $(CRASH_TEST_EXT_ARGS)
@@ -79,10 +117,13 @@ blackbox_crash_test_with_ts: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --enable_ts blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --test_multiops_txn --write_policy write_committed blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) --test_multiops_txn --txn_write_policy 0 blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --test_multiops_txn --write_policy write_prepared blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) --test_multiops_txn --txn_write_policy 1 blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_multiops_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --test_multiops_txn --txn_write_policy 2 blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_tiered_storage: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --test_tiered_storage blackbox $(CRASH_TEST_EXT_ARGS)
@@ -104,9 +145,17 @@ whitebox_crash_test_with_atomic_flush: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --cf_consistency whitebox  --random_kill_odd \
       $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
 
-whitebox_crash_test_with_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --txn whitebox --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+whitebox_crash_test_with_wc_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --txn_write_policy 0 \
+	  --random_kill_odd $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_wp_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --txn_write_policy 1 \
+      --random_kill_odd $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --txn_write_policy 2 \
+      --random_kill_odd $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
 
 whitebox_crash_test_with_ts: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --enable_ts whitebox --random_kill_odd \
@@ -119,3 +168,11 @@ whitebox_crash_test_with_tiered_storage: $(DB_STRESS_CMD)
 whitebox_crash_test_with_optimistic_txn: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --optimistic_txn whitebox --random_kill_odd \
       $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+crash_test_db_cleanup: $(DB_STRESS_CMD)
+	$(DB_STRESS_CMD) --delete_dir_and_exit=$(TEST_TMPDIR)
+
+# Old names DEPRECATED
+crash_test_with_txn: crash_test_with_wc_txn
+whitebox_crash_test_with_txn: whitebox_crash_test_with_wc_txn
+blackbox_crash_test_with_txn: blackbox_crash_test_with_wc_txn

db/arena_wrapped_db_iter.cc

@@ -42,9 +42,9 @@ Status ArenaWrappedDBIter::GetProperty(std::string prop_name,
 void ArenaWrappedDBIter::Init(
     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,
-    ColumnFamilyHandleImpl* cfh, bool expose_blob_index, bool allow_refresh) {
+    const SequenceNumber& sequence, uint64_t version_number,
+    ReadCallback* read_callback, ColumnFamilyHandleImpl* cfh,
+    bool expose_blob_index, bool allow_refresh, ReadOnlyMemTable* active_mem) {
   read_options_ = read_options;
   if (!CheckFSFeatureSupport(env->GetFileSystem().get(),
                              FSSupportedOps::kAsyncIO)) {
@@ -52,15 +52,14 @@ void ArenaWrappedDBIter::Init(
   }
   read_options_.total_order_seek |= ioptions.prefix_seek_opt_in_only;
 
-  auto mem = arena_.AllocateAligned(sizeof(DBIter));
-  db_iter_ = 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,
-                              cfh, expose_blob_index);
+  db_iter_ = DBIter::NewIter(
+      env, read_options_, ioptions, mutable_cf_options,
+      ioptions.user_comparator, /*internal_iter=*/nullptr, version, sequence,
+      read_callback, active_mem, cfh, expose_blob_index, &arena_);
 
   sv_number_ = version_number;
   allow_refresh_ = allow_refresh;
+  allow_mark_memtable_for_flush_ = active_mem;
   memtable_range_tombstone_iter_ = nullptr;
 }
 
@@ -166,9 +165,8 @@ void ArenaWrappedDBIter::DoRefresh(const Snapshot* snapshot,
     read_callback_->Refresh(read_seq);
   }
   Init(env, read_options_, cfd->ioptions(), sv->mutable_cf_options, sv->current,
-       read_seq, sv->mutable_cf_options.max_sequential_skip_in_iterations,
-       sv->version_number, read_callback_, cfh_, expose_blob_index_,
-       allow_refresh_);
+       read_seq, sv->version_number, read_callback_, cfh_, expose_blob_index_,
+       allow_refresh_, allow_mark_memtable_for_flush_ ? sv->mem : nullptr);
 
   InternalIterator* internal_iter = db_impl->NewInternalIterator(
       read_options_, cfd, sv, &arena_, read_seq,
@@ -253,20 +251,26 @@ Status ArenaWrappedDBIter::Refresh(const Snapshot* snapshot) {
 }
 
 ArenaWrappedDBIter* NewArenaWrappedDbIterator(
-    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,
-    ColumnFamilyHandleImpl* cfh, bool expose_blob_index, bool allow_refresh) {
-  ArenaWrappedDBIter* iter = new ArenaWrappedDBIter();
-  iter->Init(env, read_options, ioptions, mutable_cf_options, version, sequence,
-             max_sequential_skip_in_iterations, version_number, read_callback,
-             cfh, expose_blob_index, allow_refresh);
+    Env* env, const ReadOptions& read_options, ColumnFamilyHandleImpl* cfh,
+    SuperVersion* sv, const SequenceNumber& sequence,
+    ReadCallback* read_callback, DBImpl* db_impl, bool expose_blob_index,
+    bool allow_refresh, bool allow_mark_memtable_for_flush) {
+  ArenaWrappedDBIter* db_iter = new ArenaWrappedDBIter();
+  db_iter->Init(env, read_options, cfh->cfd()->ioptions(),
+                sv->mutable_cf_options, sv->current, sequence,
+                sv->version_number, read_callback, cfh, expose_blob_index,
+                allow_refresh,
+                allow_mark_memtable_for_flush ? sv->mem : nullptr);
   if (cfh != nullptr && allow_refresh) {
-    iter->StoreRefreshInfo(cfh, read_callback, expose_blob_index);
+    db_iter->StoreRefreshInfo(cfh, read_callback, expose_blob_index);
   }
 
-  return iter;
+  InternalIterator* internal_iter = db_impl->NewInternalIterator(
+      db_iter->GetReadOptions(), cfh->cfd(), sv, db_iter->GetArena(), sequence,
+      /*allow_unprepared_value=*/true, db_iter);
+  db_iter->SetIterUnderDBIter(internal_iter);
+
+  return db_iter;
 }
 
 }  // namespace ROCKSDB_NAMESPACE

db/arena_wrapped_db_iter.h

@@ -19,7 +19,6 @@
 #include "options/cf_options.h"
 #include "rocksdb/db.h"
 #include "rocksdb/iterator.h"
-#include "util/autovector.h"
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -99,17 +98,19 @@ class ArenaWrappedDBIter : public Iterator {
 
   bool PrepareValue() override { return db_iter_->PrepareValue(); }
 
-  void Prepare(const std::vector<ScanOptions>& scan_opts) override {
+  void Prepare(const MultiScanArgs& scan_opts) override {
     db_iter_->Prepare(scan_opts);
   }
 
+  // FIXME: we could just pass SV in for mutable cf option, version and version
+  // number, but this is used by SstFileReader which does not have a SV.
   void Init(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,
+            const SequenceNumber& sequence, uint64_t version_number,
             ReadCallback* read_callback, ColumnFamilyHandleImpl* cfh,
-            bool expose_blob_index, bool allow_refresh);
+            bool expose_blob_index, bool allow_refresh,
+            ReadOnlyMemTable* active_mem);
 
   // Store some parameters so we can refresh the iterator at a later point
   // with these same params
@@ -132,20 +133,16 @@ class ArenaWrappedDBIter : public Iterator {
   ReadCallback* read_callback_;
   bool expose_blob_index_ = false;
   bool allow_refresh_ = true;
+  bool allow_mark_memtable_for_flush_ = true;
   // If this is nullptr, it means the mutable memtable does not contain range
   // tombstone when added under this DBIter.
   std::unique_ptr<TruncatedRangeDelIterator>* memtable_range_tombstone_iter_ =
       nullptr;
 };
 
-// Generate the arena wrapped iterator class.
-// `cfh` is used for reneweal. If left null, renewal will not
-// be supported.
 ArenaWrappedDBIter* NewArenaWrappedDbIterator(
-    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,
-    ColumnFamilyHandleImpl* cfh = nullptr, bool expose_blob_index = false,
-    bool allow_refresh = true);
+    Env* env, const ReadOptions& read_options, ColumnFamilyHandleImpl* cfh,
+    SuperVersion* sv, const SequenceNumber& sequence,
+    ReadCallback* read_callback, DBImpl* db_impl, bool expose_blob_index,
+    bool allow_refresh, bool allow_mark_memtable_for_flush);
 }  // namespace ROCKSDB_NAMESPACE

db/blob/blob_fetcher.cc

@@ -5,6 +5,8 @@
 
 #include "db/blob/blob_fetcher.h"
 
+#include "db/blob/blob_file_partition_manager.h"
+#include "db/blob/blob_index.h"
 #include "db/version_set.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -14,10 +16,13 @@ Status BlobFetcher::FetchBlob(const Slice& user_key,
                               FilePrefetchBuffer* prefetch_buffer,
                               PinnableSlice* blob_value,
                               uint64_t* bytes_read) const {
-  assert(version_);
-
-  return version_->GetBlob(read_options_, user_key, blob_index_slice,
-                           prefetch_buffer, blob_value, bytes_read);
+  BlobIndex blob_index;
+  Status status = blob_index.DecodeFrom(blob_index_slice);
+  if (status.ok()) {
+    status = FetchBlob(user_key, blob_index, prefetch_buffer, blob_value,
+                       bytes_read);
+  }
+  return status;
 }
 
 Status BlobFetcher::FetchBlob(const Slice& user_key,
@@ -25,10 +30,16 @@ Status BlobFetcher::FetchBlob(const Slice& user_key,
                               FilePrefetchBuffer* prefetch_buffer,
                               PinnableSlice* blob_value,
                               uint64_t* bytes_read) const {
-  assert(version_);
+  if (!allow_write_path_fallback_) {
+    assert(version_);
 
-  return version_->GetBlob(read_options_, user_key, blob_index, prefetch_buffer,
-                           blob_value, bytes_read);
+    return version_->GetBlob(read_options_, user_key, blob_index,
+                             prefetch_buffer, blob_value, bytes_read);
+  }
+
+  return BlobFilePartitionManager::ResolveBlobDirectWriteIndex(
+      read_options_, user_key, blob_index, version_, blob_file_cache_,
+      prefetch_buffer, blob_value, bytes_read);
 }
 
 }  // namespace ROCKSDB_NAMESPACE

db/blob/blob_fetcher.h

@@ -10,17 +10,25 @@
 
 namespace ROCKSDB_NAMESPACE {
 
+class BlobFileCache;
 class Version;
 class Slice;
 class FilePrefetchBuffer;
 class PinnableSlice;
 class BlobIndex;
 
-// A thin wrapper around the blob retrieval functionality of Version.
+// A thin wrapper around blob retrieval. By default it reads through Version,
+// and it can optionally fall back to direct-write blob files that are not yet
+// manifest-visible.
 class BlobFetcher {
  public:
-  BlobFetcher(const Version* version, const ReadOptions& read_options)
-      : version_(version), read_options_(read_options) {}
+  BlobFetcher(const Version* version, const ReadOptions& read_options,
+              BlobFileCache* blob_file_cache = nullptr,
+              bool allow_write_path_fallback = false)
+      : version_(version),
+        read_options_(read_options),
+        blob_file_cache_(blob_file_cache),
+        allow_write_path_fallback_(allow_write_path_fallback) {}
 
   Status FetchBlob(const Slice& user_key, const Slice& blob_index_slice,
                    FilePrefetchBuffer* prefetch_buffer,
@@ -33,5 +41,7 @@ class BlobFetcher {
  private:
   const Version* version_;
   ReadOptions read_options_;
+  BlobFileCache* blob_file_cache_;
+  bool allow_write_path_fallback_;
 };
 }  // namespace ROCKSDB_NAMESPACE

db/blob/blob_file_builder.cc

@@ -67,6 +67,14 @@ BlobFileBuilder::BlobFileBuilder(
       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),
+      // TODO with schema change: support custom compression manager and options
+      // such as max_compressed_bytes_per_kb
+      // NOTE: returns nullptr for kNoCompression
+      blob_compressor_(GetBuiltinV2CompressionManager()->GetCompressor(
+          mutable_cf_options->blob_compression_opts, blob_compression_type_)),
+      blob_compressor_wa_(blob_compressor_
+                              ? blob_compressor_->ObtainWorkingArea()
+                              : Compressor::ManagedWorkingArea{}),
       prepopulate_blob_cache_(mutable_cf_options->prepopulate_blob_cache),
       file_options_(file_options),
       write_options_(write_options),
@@ -101,7 +109,7 @@ Status BlobFileBuilder::Add(const Slice& key, const Slice& value,
   assert(blob_index);
   assert(blob_index->empty());
 
-  if (value.size() < min_blob_size_) {
+  if (value.empty() || value.size() < min_blob_size_) {
     return Status::OK();
   }
 
@@ -113,7 +121,7 @@ Status BlobFileBuilder::Add(const Slice& key, const Slice& value,
   }
 
   Slice blob = value;
-  std::string compressed_blob;
+  GrowableBuffer compressed_blob;
 
   {
     const Status s = CompressBlobIfNeeded(&blob, &compressed_blob);
@@ -254,37 +262,27 @@ Status BlobFileBuilder::OpenBlobFileIfNeeded() {
 }
 
 Status BlobFileBuilder::CompressBlobIfNeeded(
-    Slice* blob, std::string* compressed_blob) const {
+    Slice* blob, GrowableBuffer* compressed_blob) const {
   assert(blob);
   assert(compressed_blob);
   assert(compressed_blob->empty());
   assert(immutable_options_);
 
-  if (blob_compression_type_ == kNoCompression) {
+  if (!blob_compressor_) {
+    assert(blob_compression_type_ == kNoCompression);
     return Status::OK();
   }
+  assert(blob_compression_type_ != kNoCompression);
 
-  // TODO: allow user CompressionOptions, including max_compressed_bytes_per_kb
-  CompressionOptions opts;
-  CompressionContext context(blob_compression_type_, opts);
-  constexpr uint64_t sample_for_compression = 0;
+  // WART: always stored as compressed even when that increases the size.
 
-  CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(),
-                       blob_compression_type_, sample_for_compression);
-
-  constexpr uint32_t compression_format_version = 2;
-
-  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");
+  Status s;
+  StopWatch stop_watch(immutable_options_->clock, immutable_options_->stats,
+                       BLOB_DB_COMPRESSION_MICROS);
+  s = LegacyForceBuiltinCompression(*blob_compressor_, &blob_compressor_wa_,
+                                    *blob, compressed_blob);
+  if (!s.ok()) {
+    return s;
   }
 
   *blob = Slice(*compressed_blob);

db/blob/blob_file_builder.h

@@ -10,12 +10,14 @@
 #include <string>
 #include <vector>
 
+#include "rocksdb/advanced_compression.h"
 #include "rocksdb/advanced_options.h"
 #include "rocksdb/compression_type.h"
 #include "rocksdb/env.h"
 #include "rocksdb/options.h"
 #include "rocksdb/rocksdb_namespace.h"
 #include "rocksdb/types.h"
+#include "util/aligned_buffer.h"
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -76,7 +78,8 @@ class BlobFileBuilder {
  private:
   bool IsBlobFileOpen() const;
   Status OpenBlobFileIfNeeded();
-  Status CompressBlobIfNeeded(Slice* blob, std::string* compressed_blob) const;
+  Status CompressBlobIfNeeded(Slice* blob,
+                              GrowableBuffer* compressed_blob) const;
   Status WriteBlobToFile(const Slice& key, const Slice& blob,
                          uint64_t* blob_file_number, uint64_t* blob_offset);
   Status CloseBlobFile();
@@ -91,6 +94,8 @@ class BlobFileBuilder {
   uint64_t min_blob_size_;
   uint64_t blob_file_size_;
   CompressionType blob_compression_type_;
+  std::unique_ptr<Compressor> blob_compressor_;
+  mutable Compressor::ManagedWorkingArea blob_compressor_wa_;
   PrepopulateBlobCache prepopulate_blob_cache_;
   const FileOptions* file_options_;
   const WriteOptions* write_options_;

db/blob/blob_file_builder_test.cc

@@ -403,23 +403,19 @@ TEST_F(BlobFileBuilderTest, Compression) {
   ASSERT_EQ(blob_file_addition.GetBlobFileNumber(), blob_file_number);
   ASSERT_EQ(blob_file_addition.GetTotalBlobCount(), 1);
 
-  CompressionOptions opts;
-  CompressionContext context(kSnappyCompression, opts);
-  constexpr uint64_t sample_for_compression = 0;
-
-  CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(),
-                       kSnappyCompression, sample_for_compression);
-
-  std::string compressed_value;
-  ASSERT_TRUE(Snappy_Compress(info, uncompressed_value.data(),
-                              uncompressed_value.size(), &compressed_value));
+  auto compressor =
+      GetBuiltinV2CompressionManager()->GetCompressor({}, kSnappyCompression);
+  GrowableBuffer compressed_value;
+  ASSERT_OK(LegacyForceBuiltinCompression(*compressor, /*working_area=*/nullptr,
+                                          uncompressed_value,
+                                          &compressed_value));
 
   ASSERT_EQ(blob_file_addition.GetTotalBlobBytes(),
             BlobLogRecord::kHeaderSize + key_size + compressed_value.size());
 
   // Verify the contents of the new blob file as well as the blob reference
   std::vector<std::pair<std::string, std::string>> expected_key_value_pairs{
-      {key, compressed_value}};
+      {key, compressed_value.AsSlice().ToString()}};
   std::vector<std::string> blob_indexes{blob_index};
 
   VerifyBlobFile(blob_file_number, blob_file_path, column_family_id,
@@ -458,11 +454,12 @@ TEST_F(BlobFileBuilderTest, CompressionError) {
       nullptr /*IOTracer*/, nullptr /*BlobFileCompletionCallback*/,
       BlobFileCreationReason::kFlush, &blob_file_paths, &blob_file_additions);
 
-  SyncPoint::GetInstance()->SetCallBack("CompressData:TamperWithReturnValue",
-                                        [](void* arg) {
-                                          bool* ret = static_cast<bool*>(arg);
-                                          *ret = false;
-                                        });
+  SyncPoint::GetInstance()->SetCallBack(
+      "LegacyForceBuiltinCompression:TamperWithStatus", [](void* arg) {
+        Status* ret = static_cast<Status*>(arg);
+        ASSERT_OK(*ret);
+        *ret = Status::Corruption("Tampered result");
+      });
   SyncPoint::GetInstance()->EnableProcessing();
 
   constexpr char key[] = "1";
@@ -470,7 +467,7 @@ TEST_F(BlobFileBuilderTest, CompressionError) {
 
   std::string blob_index;
 
-  ASSERT_TRUE(builder.Add(key, value, &blob_index).IsCorruption());
+  ASSERT_EQ(builder.Add(key, value, &blob_index).code(), Status::kCorruption);
 
   SyncPoint::GetInstance()->DisableProcessing();
   SyncPoint::GetInstance()->ClearAllCallBacks();

db/blob/blob_file_cache.cc

@@ -9,6 +9,7 @@
 #include <memory>
 
 #include "db/blob/blob_file_reader.h"
+#include "logging/logging.h"
 #include "options/cf_options.h"
 #include "rocksdb/cache.h"
 #include "rocksdb/slice.h"
@@ -38,7 +39,8 @@ BlobFileCache::BlobFileCache(Cache* cache,
 
 Status BlobFileCache::GetBlobFileReader(
     const ReadOptions& read_options, uint64_t blob_file_number,
-    CacheHandleGuard<BlobFileReader>* blob_file_reader) {
+    CacheHandleGuard<BlobFileReader>* blob_file_reader,
+    bool allow_footer_skip_retry) {
   assert(blob_file_reader);
   assert(blob_file_reader->IsEmpty());
 
@@ -73,10 +75,22 @@ Status BlobFileCache::GetBlobFileReader(
 
   {
     assert(file_options_);
-    const Status s = BlobFileReader::Create(
+    Status s = BlobFileReader::Create(
         *immutable_options_, read_options, *file_options_, column_family_id_,
-        blob_file_read_hist_, blob_file_number, io_tracer_, &reader);
+        blob_file_read_hist_, blob_file_number, io_tracer_,
+        /*skip_footer_validation=*/false, &reader);
+    if (!s.ok() && s.IsCorruption() && allow_footer_skip_retry) {
+      reader.reset();
+      s = BlobFileReader::Create(
+          *immutable_options_, read_options, *file_options_, column_family_id_,
+          blob_file_read_hist_, blob_file_number, io_tracer_,
+          /*skip_footer_validation=*/true, &reader);
+    }
     if (!s.ok()) {
+      ROCKS_LOG_WARN(immutable_options_->logger,
+                     "BlobFileCache open failed for blob file %" PRIu64
+                     " in CF %u: %s",
+                     blob_file_number, column_family_id_, s.ToString().c_str());
       RecordTick(statistics, NO_FILE_ERRORS);
       return s;
     }
@@ -99,12 +113,120 @@ Status BlobFileCache::GetBlobFileReader(
   return Status::OK();
 }
 
+Status BlobFileCache::OpenBlobFileReaderUncached(
+    const ReadOptions& read_options, uint64_t blob_file_number,
+    std::unique_ptr<BlobFileReader>* blob_file_reader,
+    bool allow_footer_skip_retry) {
+  assert(blob_file_reader);
+  assert(!*blob_file_reader);
+
+  Statistics* const statistics = immutable_options_->stats;
+  RecordTick(statistics, NO_FILE_OPENS);
+
+  Status s = BlobFileReader::Create(
+      *immutable_options_, read_options, *file_options_, column_family_id_,
+      blob_file_read_hist_, blob_file_number, io_tracer_,
+      /*skip_footer_validation=*/false, blob_file_reader);
+  if (!s.ok() && s.IsCorruption() && allow_footer_skip_retry) {
+    blob_file_reader->reset();
+    s = BlobFileReader::Create(
+        *immutable_options_, read_options, *file_options_, column_family_id_,
+        blob_file_read_hist_, blob_file_number, io_tracer_,
+        /*skip_footer_validation=*/true, blob_file_reader);
+  }
+  if (!s.ok()) {
+    RecordTick(statistics, NO_FILE_ERRORS);
+  }
+  return s;
+}
+
+Status BlobFileCache::InsertBlobFileReader(
+    uint64_t blob_file_number,
+    std::unique_ptr<BlobFileReader>* blob_file_reader,
+    CacheHandleGuard<BlobFileReader>* cached_blob_file_reader) {
+  assert(blob_file_reader);
+  assert(*blob_file_reader);
+  assert(cached_blob_file_reader);
+  assert(cached_blob_file_reader->IsEmpty());
+
+  const Slice key = GetSliceForKey(&blob_file_number);
+  // Serialize refreshes for the same blob file. The cache API does not expose
+  // a conditional replace, so refresh is intentionally modeled as
+  // Lookup/optional Erase/Insert under this per-key mutex.
+  MutexLock lock(&mutex_.Get(key));
+
+  TypedHandle* handle = cache_.Lookup(key);
+  if (handle) {
+    *cached_blob_file_reader = cache_.Guard(handle);
+    blob_file_reader->reset();
+    return Status::OK();
+  }
+
+  constexpr size_t charge = 1;
+  Status s = cache_.Insert(key, blob_file_reader->get(), charge, &handle);
+  if (!s.ok()) {
+    RecordTick(immutable_options_->stats, NO_FILE_ERRORS);
+    return s;
+  }
+
+  // Ownership transferred to the cache.
+  [[maybe_unused]] BlobFileReader* released_reader =
+      blob_file_reader->release();
+  *cached_blob_file_reader = cache_.Guard(handle);
+  return Status::OK();
+}
+
+Status BlobFileCache::RefreshBlobFileReader(
+    uint64_t blob_file_number,
+    std::unique_ptr<BlobFileReader>* blob_file_reader,
+    CacheHandleGuard<BlobFileReader>* cached_blob_file_reader) {
+  assert(blob_file_reader);
+  assert(*blob_file_reader);
+  assert(cached_blob_file_reader);
+  assert(cached_blob_file_reader->IsEmpty());
+
+  const Slice key = GetSliceForKey(&blob_file_number);
+  MutexLock lock(&mutex_.Get(key));
+
+  TypedHandle* handle = cache_.Lookup(key);
+  if (handle) {
+    BlobFileReader* const cached_reader = cache_.Value(handle);
+    assert(cached_reader != nullptr);
+
+    // Active direct-write blob files can grow between refresh attempts. Keep
+    // whichever reader observed the larger on-disk size so an older refresh
+    // cannot overwrite a newer one that another thread already installed.
+    if (cached_reader->GetFileSize() >= (*blob_file_reader)->GetFileSize()) {
+      *cached_blob_file_reader = cache_.Guard(handle);
+      blob_file_reader->reset();
+      return Status::OK();
+    }
+
+    cache_.Release(handle);
+    cache_.get()->Erase(key);
+  }
+
+  constexpr size_t charge = 1;
+  Status s = cache_.Insert(key, blob_file_reader->get(), charge, &handle);
+  if (!s.ok()) {
+    RecordTick(immutable_options_->stats, NO_FILE_ERRORS);
+    return s;
+  }
+
+  // Ownership transferred to the cache.
+  [[maybe_unused]] BlobFileReader* released_reader =
+      blob_file_reader->release();
+  *cached_blob_file_reader = cache_.Guard(handle);
+  return Status::OK();
+}
+
 void BlobFileCache::Evict(uint64_t blob_file_number) {
   // NOTE: sharing same Cache with table_cache
   const Slice key = GetSliceForKey(&blob_file_number);
 
   assert(cache_);
 
+  MutexLock lock(&mutex_.Get(key));
   cache_.get()->Erase(key);
 }
 

db/blob/blob_file_cache.h

@@ -32,9 +32,35 @@ class BlobFileCache {
   BlobFileCache(const BlobFileCache&) = delete;
   BlobFileCache& operator=(const BlobFileCache&) = delete;
 
+  // Returns a cached reader for `blob_file_number`, opening and caching it on
+  // miss. If `allow_footer_skip_retry` is true, a footer-validation corruption
+  // retries once without requiring a footer.
   Status GetBlobFileReader(const ReadOptions& read_options,
                            uint64_t blob_file_number,
-                           CacheHandleGuard<BlobFileReader>* blob_file_reader);
+                           CacheHandleGuard<BlobFileReader>* blob_file_reader,
+                           bool allow_footer_skip_retry = false);
+
+  // Opens a blob file reader without inserting it into the cache.
+  Status OpenBlobFileReaderUncached(
+      const ReadOptions& read_options, uint64_t blob_file_number,
+      std::unique_ptr<BlobFileReader>* blob_file_reader,
+      bool allow_footer_skip_retry = false);
+
+  // Inserts a freshly opened uncached reader unless another thread already
+  // cached the same blob file.
+  Status InsertBlobFileReader(
+      uint64_t blob_file_number,
+      std::unique_ptr<BlobFileReader>* blob_file_reader,
+      CacheHandleGuard<BlobFileReader>* cached_blob_file_reader);
+
+  // Installs a refresh-opened reader into the cache. If another thread has
+  // already cached a reader opened on at least as large a file size, keep that
+  // reader instead so a racing refresh cannot reintroduce an older active-file
+  // view after the blob file grows.
+  Status RefreshBlobFileReader(
+      uint64_t blob_file_number,
+      std::unique_ptr<BlobFileReader>* blob_file_reader,
+      CacheHandleGuard<BlobFileReader>* cached_blob_file_reader);
 
   // Called when a blob file is obsolete to ensure it is removed from the cache
   // to avoid effectively leaking the open file and assicated memory

db/blob/blob_file_cache_test.cc

@@ -192,6 +192,102 @@ TEST_F(BlobFileCacheTest, GetBlobFileReader_Race) {
   SyncPoint::GetInstance()->ClearAllCallBacks();
 }
 
+TEST_F(BlobFileCacheTest, RefreshBlobFileReaderPrefersLargestObservedFileSize) {
+  Options options;
+  options.env = mock_env_.get();
+  options.statistics = CreateDBStatistics();
+  options.cf_paths.emplace_back(
+      test::PerThreadDBPath(
+          mock_env_.get(),
+          "BlobFileCacheTest_"
+          "RefreshBlobFileReaderPrefersLargestObservedFileSize"),
+      0);
+  options.enable_blob_files = true;
+
+  constexpr uint32_t column_family_id = 1;
+  ImmutableOptions immutable_options(options);
+  constexpr uint64_t blob_file_number = 123;
+
+  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_options.fs.get(), blob_file_path, &file,
+                            FileOptions()));
+
+  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_options.clock,
+                                statistics, blob_file_number, use_fsync,
+                                do_flush);
+
+  constexpr bool has_ttl = false;
+  constexpr ExpirationRange expiration_range;
+  BlobLogHeader header(column_family_id, kNoCompression, has_ttl,
+                       expiration_range);
+  ASSERT_OK(blob_log_writer.WriteHeader(WriteOptions(), header));
+
+  uint64_t key_offset = 0;
+  uint64_t blob_offset = 0;
+  ASSERT_OK(blob_log_writer.AddRecord(WriteOptions(), "key0", "blob0",
+                                      &key_offset, &blob_offset));
+  ASSERT_OK(blob_log_writer.Sync(WriteOptions()));
+
+  constexpr size_t capacity = 10;
+  std::shared_ptr<Cache> backing_cache = NewLRUCache(capacity);
+
+  FileOptions file_options;
+  constexpr HistogramImpl* blob_file_read_hist = nullptr;
+  BlobFileCache blob_file_cache(backing_cache.get(), &immutable_options,
+                                &file_options, column_family_id,
+                                blob_file_read_hist, nullptr /*IOTracer*/);
+
+  const ReadOptions read_options;
+  std::unique_ptr<BlobFileReader> stale_reader;
+  ASSERT_OK(blob_file_cache.OpenBlobFileReaderUncached(
+      read_options, blob_file_number, &stale_reader,
+      /*allow_footer_skip_retry=*/true));
+
+  std::unique_ptr<BlobFileReader> initial_cached_reader;
+  ASSERT_OK(blob_file_cache.OpenBlobFileReaderUncached(
+      read_options, blob_file_number, &initial_cached_reader,
+      /*allow_footer_skip_retry=*/true));
+
+  CacheHandleGuard<BlobFileReader> cached_reader;
+  ASSERT_OK(blob_file_cache.RefreshBlobFileReader(
+      blob_file_number, &initial_cached_reader, &cached_reader));
+  ASSERT_NE(cached_reader.GetValue(), nullptr);
+  const uint64_t initial_file_size = cached_reader.GetValue()->GetFileSize();
+
+  ASSERT_OK(blob_log_writer.AddRecord(WriteOptions(), "key1", "blob1",
+                                      &key_offset, &blob_offset));
+  ASSERT_OK(blob_log_writer.Sync(WriteOptions()));
+
+  std::unique_ptr<BlobFileReader> fresh_reader;
+  ASSERT_OK(blob_file_cache.OpenBlobFileReaderUncached(
+      read_options, blob_file_number, &fresh_reader,
+      /*allow_footer_skip_retry=*/true));
+  ASSERT_GT(fresh_reader->GetFileSize(), initial_file_size);
+
+  CacheHandleGuard<BlobFileReader> refreshed_reader;
+  ASSERT_OK(blob_file_cache.RefreshBlobFileReader(
+      blob_file_number, &fresh_reader, &refreshed_reader));
+  ASSERT_NE(refreshed_reader.GetValue(), nullptr);
+  ASSERT_GT(refreshed_reader.GetValue()->GetFileSize(), initial_file_size);
+  BlobFileReader* const largest_reader = refreshed_reader.GetValue();
+
+  CacheHandleGuard<BlobFileReader> preserved_reader;
+  ASSERT_OK(blob_file_cache.RefreshBlobFileReader(
+      blob_file_number, &stale_reader, &preserved_reader));
+  ASSERT_NE(preserved_reader.GetValue(), nullptr);
+  ASSERT_EQ(preserved_reader.GetValue(), largest_reader);
+  ASSERT_EQ(stale_reader.get(), nullptr);
+}
+
 TEST_F(BlobFileCacheTest, GetBlobFileReader_IOError) {
   Options options;
   options.env = mock_env_.get();

db/blob/blob_file_meta.h

@@ -6,6 +6,7 @@
 #pragma once
 
 #include <cassert>
+#include <cstdint>
 #include <iosfwd>
 #include <memory>
 #include <string>

db/blob/blob_file_partition_manager.cc

@@ -0,0 +1,851 @@
+//  Copyright (c) Meta Platforms, Inc. and affiliates.
+//  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_file_partition_manager.h"
+
+#include <array>
+#include <atomic>
+#include <cinttypes>
+#include <memory>
+#include <utility>
+
+#include "cache/cache_key.h"
+#include "cache/typed_cache.h"
+#include "db/blob/blob_contents.h"
+#include "db/blob/blob_file_cache.h"
+#include "db/blob/blob_file_completion_callback.h"
+#include "db/blob/blob_file_reader.h"
+#include "db/blob/blob_index.h"
+#include "db/blob/blob_log_writer.h"
+#include "db/version_set.h"
+#include "file/filename.h"
+#include "file/read_write_util.h"
+#include "file/writable_file_writer.h"
+#include "logging/logging.h"
+#include "util/aligned_buffer.h"
+#include "util/compression.h"
+#include "util/mutexlock.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+namespace {
+
+class RoundRobinBlobFilePartitionStrategy : public BlobFilePartitionStrategy {
+ public:
+  using BlobFilePartitionStrategy::SelectPartition;
+
+  const char* Name() const override {
+    return "RoundRobinBlobFilePartitionStrategy";
+  }
+
+  uint32_t SelectPartition(uint32_t num_partitions,
+                           uint32_t /*column_family_id*/, const Slice& /*key*/,
+                           const Slice& /*value*/) override {
+    assert(num_partitions > 0);
+    return static_cast<uint32_t>(
+        next_partition_.fetch_add(1, std::memory_order_relaxed) %
+        static_cast<uint64_t>(num_partitions));
+  }
+
+ private:
+  std::atomic<uint64_t> next_partition_{0};
+};
+
+struct DirectWriteCompressionState {
+  CompressionOptions compression_opts;
+  // `working_area` must be released before its owning compressor.
+  std::unique_ptr<Compressor> compressor;
+  Compressor::ManagedWorkingArea working_area;
+};
+
+DirectWriteCompressionState& GetDirectWriteCompressionState(
+    CompressionType compression, const CompressionOptions& compression_opts) {
+  assert(compression <= kLastBuiltinCompression);
+
+  static thread_local std::array<DirectWriteCompressionState,
+                                 static_cast<size_t>(kLastBuiltinCompression) +
+                                     1>
+      compression_states;
+
+  auto& compression_state =
+      compression_states[static_cast<size_t>(compression)];
+  if (compression != kNoCompression &&
+      (compression_state.compressor == nullptr ||
+       compression_state.compression_opts != compression_opts)) {
+    // BDW compression settings are mutable, so rebuild the per-thread cached
+    // compressor when the latest published opts for this type change.
+    compression_state.working_area = Compressor::ManagedWorkingArea{};
+    compression_state.compressor.reset();
+    compression_state.compression_opts = compression_opts;
+    compression_state.compressor =
+        GetBuiltinV2CompressionManager()->GetCompressor(compression_opts,
+                                                        compression);
+    if (compression_state.compressor != nullptr) {
+      compression_state.working_area =
+          compression_state.compressor->ObtainWorkingArea();
+    }
+  }
+
+  return compression_state;
+}
+
+}  // namespace
+
+BlobFilePartitionManager::BlobFilePartitionManager(
+    uint32_t num_partitions,
+    std::shared_ptr<BlobFilePartitionStrategy> strategy,
+    FileNumberAllocator file_number_allocator, FileSystem* fs,
+    SystemClock* clock, Statistics* statistics, const FileOptions& file_options,
+    std::string db_path, std::string column_family_name,
+    uint64_t blob_file_size, bool use_fsync, BlobFileCache* blob_file_cache,
+    BlobFileCompletionCallback* blob_callback,
+    const std::vector<std::shared_ptr<EventListener>>& listeners,
+    FileChecksumGenFactory* file_checksum_gen_factory,
+    const FileTypeSet& checksum_handoff_file_types,
+    const std::shared_ptr<IOTracer>& io_tracer, std::string db_id,
+    std::string db_session_id, Logger* info_log)
+    : num_partitions_(num_partitions == 0 ? 1 : num_partitions),
+      strategy_(strategy != nullptr
+                    ? std::move(strategy)
+                    : std::make_shared<RoundRobinBlobFilePartitionStrategy>()),
+      file_number_allocator_(std::move(file_number_allocator)),
+      fs_(fs),
+      clock_(clock),
+      statistics_(statistics),
+      file_options_(file_options),
+      db_path_(std::move(db_path)),
+      column_family_name_(std::move(column_family_name)),
+      blob_file_size_(blob_file_size),
+      use_fsync_(use_fsync),
+      blob_file_cache_(blob_file_cache),
+      blob_callback_(blob_callback),
+      listeners_(listeners),
+      file_checksum_gen_factory_(file_checksum_gen_factory),
+      checksum_handoff_file_types_(checksum_handoff_file_types),
+      io_tracer_(io_tracer),
+      db_id_(std::move(db_id)),
+      db_session_id_(std::move(db_session_id)),
+      info_log_(info_log) {
+  partitions_.reserve(num_partitions_);
+  for (uint32_t i = 0; i < num_partitions_; ++i) {
+    partitions_.emplace_back(new Partition());
+  }
+}
+
+BlobFilePartitionManager::~BlobFilePartitionManager() {
+  if (blob_file_cache_ != nullptr) {
+    std::vector<uint64_t> tracked_file_numbers;
+    {
+      ReadLock lock(&file_partition_mutex_);
+      tracked_file_numbers.reserve(file_to_partition_.size());
+      for (const auto& entry : file_to_partition_) {
+        tracked_file_numbers.push_back(entry.first);
+      }
+    }
+
+    for (uint64_t file_number : tracked_file_numbers) {
+      // Dropping the CF or closing the DB can destroy the manager while active
+      // direct-write readers are still cached. Evict them before the CF-owned
+      // blob cache goes away so Close() does not retain obsolete footer-less
+      // readers for files that are no longer live.
+      blob_file_cache_->Evict(file_number);
+    }
+  }
+}
+
+void BlobFilePartitionManager::ResetPartitionState(Partition* partition) {
+  partition->writer.reset();
+  partition->file_number = 0;
+  partition->file_size = 0;
+  partition->blob_count = 0;
+  partition->total_blob_bytes = 0;
+  partition->garbage_blob_count = 0;
+  partition->garbage_blob_bytes = 0;
+  partition->column_family_id = 0;
+  partition->compression = kNoCompression;
+  partition->sync_required = false;
+}
+
+void BlobFilePartitionManager::AddFilePartitionMapping(uint64_t file_number,
+                                                       uint32_t partition_idx) {
+  WriteLock lock(&file_partition_mutex_);
+  file_to_partition_[file_number] = partition_idx;
+}
+
+void BlobFilePartitionManager::RemoveFilePartitionMapping(
+    uint64_t file_number) {
+  WriteLock lock(&file_partition_mutex_);
+  file_to_partition_.erase(file_number);
+}
+
+Status BlobFilePartitionManager::OpenNewBlobFile(Partition* partition,
+                                                 uint32_t column_family_id,
+                                                 CompressionType compression,
+                                                 uint32_t partition_idx) {
+  assert(partition != nullptr);
+  assert(!partition->writer);
+
+  const uint64_t blob_file_number = file_number_allocator_();
+  const std::string blob_file_path = BlobFileName(db_path_, blob_file_number);
+
+  AddFilePartitionMapping(blob_file_number, partition_idx);
+
+  if (blob_callback_ != nullptr) {
+    blob_callback_->OnBlobFileCreationStarted(
+        blob_file_path, column_family_name_,
+        /*job_id=*/0, BlobFileCreationReason::kFlush);
+  }
+
+  std::unique_ptr<FSWritableFile> file;
+  Status s = NewWritableFile(fs_, blob_file_path, &file, file_options_);
+  if (!s.ok()) {
+    RemoveFilePartitionMapping(blob_file_number);
+    return s;
+  }
+
+  const bool perform_data_verification =
+      checksum_handoff_file_types_.Contains(FileType::kBlobFile);
+  auto file_writer = std::make_unique<WritableFileWriter>(
+      std::move(file), blob_file_path, file_options_, clock_, io_tracer_,
+      statistics_, Histograms::BLOB_DB_BLOB_FILE_WRITE_MICROS, listeners_,
+      file_checksum_gen_factory_, perform_data_verification);
+
+  // This only drains WritableFileWriter's buffered bytes so readers can see
+  // each appended record promptly. Durability still comes from SyncAllOpenFiles
+  // or AppendFooter(), both of which call Sync().
+  constexpr bool kDoFlushEachRecord = true;
+  auto blob_log_writer = std::make_unique<BlobLogWriter>(
+      std::move(file_writer), clock_, statistics_, blob_file_number, use_fsync_,
+      kDoFlushEachRecord);
+
+  constexpr bool has_ttl = false;
+  constexpr ExpirationRange expiration_range{};
+  BlobLogHeader header(column_family_id, compression, has_ttl,
+                       expiration_range);
+  s = blob_log_writer->WriteHeader(WriteOptions(), header);
+  if (!s.ok()) {
+    RemoveFilePartitionMapping(blob_file_number);
+    return s;
+  }
+
+  partition->writer = std::move(blob_log_writer);
+  partition->file_number = blob_file_number;
+  partition->file_size = BlobLogHeader::kSize;
+  partition->blob_count = 0;
+  partition->total_blob_bytes = 0;
+  partition->garbage_blob_count = 0;
+  partition->garbage_blob_bytes = 0;
+  partition->column_family_id = column_family_id;
+  partition->compression = compression;
+  partition->sync_required = false;
+  return Status::OK();
+}
+
+Status BlobFilePartitionManager::SealActiveBlobFile(
+    const WriteOptions& write_options, Partition* partition,
+    SealedFile* sealed_file) {
+  assert(partition != nullptr);
+  assert(partition->writer);
+  assert(sealed_file != nullptr);
+
+  const uint64_t file_number = partition->file_number;
+  Status s =
+      FinalizeBlobFile(write_options, partition->writer.get(), file_number,
+                       partition->blob_count, partition->total_blob_bytes,
+                       &sealed_file->addition);
+  if (!s.ok()) {
+    RemoveFilePartitionMapping(file_number);
+    ResetPartitionState(partition);
+    return s;
+  }
+
+  sealed_file->garbage_blob_count = partition->garbage_blob_count;
+  sealed_file->garbage_blob_bytes = partition->garbage_blob_bytes;
+  ResetPartitionState(partition);
+  return Status::OK();
+}
+
+Status BlobFilePartitionManager::SealDeferredFile(
+    const WriteOptions& write_options, DeferredFile* deferred,
+    SealedFile* sealed_file) {
+  assert(deferred != nullptr);
+  assert(deferred->writer);
+  assert(sealed_file != nullptr);
+
+  Status s = FinalizeBlobFile(
+      write_options, deferred->writer.get(), deferred->file_number,
+      deferred->blob_count, deferred->total_blob_bytes, &sealed_file->addition);
+  if (!s.ok()) {
+    RemoveFilePartitionMapping(deferred->file_number);
+    return s;
+  }
+
+  sealed_file->garbage_blob_count = deferred->garbage_blob_count;
+  sealed_file->garbage_blob_bytes = deferred->garbage_blob_bytes;
+  deferred->writer.reset();
+  return Status::OK();
+}
+
+Status BlobFilePartitionManager::FinalizeBlobFile(
+    const WriteOptions& write_options, BlobLogWriter* writer,
+    uint64_t file_number, uint64_t blob_count, uint64_t total_blob_bytes,
+    BlobFileAddition* addition) {
+  assert(writer != nullptr);
+  assert(addition != nullptr);
+
+  BlobLogFooter footer;
+  footer.blob_count = blob_count;
+
+  std::string checksum_method;
+  std::string checksum_value;
+  Status s = writer->AppendFooter(write_options, footer, &checksum_method,
+                                  &checksum_value);
+  if (!s.ok()) {
+    return s;
+  }
+
+  if (blob_callback_ != nullptr) {
+    const std::string blob_file_path = BlobFileName(db_path_, file_number);
+    s = blob_callback_->OnBlobFileCompleted(
+        blob_file_path, column_family_name_, /*job_id=*/0, file_number,
+        BlobFileCreationReason::kFlush, s, checksum_value, checksum_method,
+        blob_count, total_blob_bytes);
+    if (!s.ok()) {
+      return s;
+    }
+  }
+
+  *addition =
+      BlobFileAddition(file_number, blob_count, total_blob_bytes,
+                       std::move(checksum_method), std::move(checksum_value));
+  return Status::OK();
+}
+
+void BlobFilePartitionManager::AddSealedFileGarbage(
+    const SealedFile& sealed_file, std::vector<BlobFileGarbage>* garbages) {
+  assert(garbages != nullptr);
+
+  if (sealed_file.garbage_blob_count == 0) {
+    assert(sealed_file.garbage_blob_bytes == 0);
+    return;
+  }
+
+  garbages->emplace_back(sealed_file.addition.GetBlobFileNumber(),
+                         sealed_file.garbage_blob_count,
+                         sealed_file.garbage_blob_bytes);
+}
+
+bool BlobFilePartitionManager::MarkPartitionGarbage(Partition* partition,
+                                                    uint64_t file_number,
+                                                    uint64_t blob_count,
+                                                    uint64_t blob_bytes) {
+  assert(partition != nullptr);
+
+  if (!partition->writer || partition->file_number != file_number) {
+    return false;
+  }
+
+  partition->garbage_blob_count += blob_count;
+  partition->garbage_blob_bytes += blob_bytes;
+  assert(partition->garbage_blob_count <= partition->blob_count);
+  assert(partition->garbage_blob_bytes <= partition->total_blob_bytes);
+  return true;
+}
+
+bool BlobFilePartitionManager::MarkDeferredFileGarbage(DeferredFile* deferred,
+                                                       uint64_t file_number,
+                                                       uint64_t blob_count,
+                                                       uint64_t blob_bytes) {
+  assert(deferred != nullptr);
+
+  if (deferred->file_number != file_number) {
+    return false;
+  }
+
+  deferred->garbage_blob_count += blob_count;
+  deferred->garbage_blob_bytes += blob_bytes;
+  assert(deferred->garbage_blob_count <= deferred->blob_count);
+  assert(deferred->garbage_blob_bytes <= deferred->total_blob_bytes);
+  return true;
+}
+
+bool BlobFilePartitionManager::MarkSealedFileGarbage(
+    std::vector<SealedFile>* sealed_files, uint64_t file_number,
+    uint64_t blob_count, uint64_t blob_bytes) {
+  assert(sealed_files != nullptr);
+
+  for (auto& sealed_file : *sealed_files) {
+    if (sealed_file.addition.GetBlobFileNumber() != file_number) {
+      continue;
+    }
+
+    sealed_file.garbage_blob_count += blob_count;
+    sealed_file.garbage_blob_bytes += blob_bytes;
+    assert(sealed_file.garbage_blob_count <=
+           sealed_file.addition.GetTotalBlobCount());
+    assert(sealed_file.garbage_blob_bytes <=
+           sealed_file.addition.GetTotalBlobBytes());
+    return true;
+  }
+
+  return false;
+}
+
+Status BlobFilePartitionManager::MaybePrepopulateBlobCache(
+    const BlobDirectWriteSettings& settings, const Slice& original_value,
+    uint64_t blob_file_number, uint64_t blob_offset) {
+  if (settings.blob_cache == nullptr ||
+      settings.prepopulate_blob_cache != PrepopulateBlobCache::kFlushOnly) {
+    return Status::OK();
+  }
+
+  FullTypedCacheInterface<BlobContents, BlobContentsCreator> blob_cache{
+      settings.blob_cache};
+  const OffsetableCacheKey base_cache_key(db_id_, db_session_id_,
+                                          blob_file_number);
+  const CacheKey cache_key = base_cache_key.WithOffset(blob_offset);
+  return blob_cache.InsertSaved(cache_key.AsSlice(), original_value, nullptr,
+                                Cache::Priority::BOTTOM,
+                                CacheTier::kVolatileTier);
+}
+
+uint32_t BlobFilePartitionManager::SelectWideColumnPartition(
+    uint32_t column_family_id, const Slice& key,
+    const WideColumns& columns) const {
+  return strategy_->SelectPartition(num_partitions_, column_family_id, key,
+                                    columns) %
+         num_partitions_;
+}
+
+Status BlobFilePartitionManager::WriteBlob(
+    const WriteOptions& write_options, uint32_t column_family_id,
+    CompressionType compression, const Slice& key, const Slice& value,
+    uint64_t* blob_file_number, uint64_t* blob_offset, uint64_t* blob_size,
+    const BlobDirectWriteSettings& settings, const uint32_t* partition_idx) {
+  assert(blob_file_number != nullptr);
+  assert(blob_offset != nullptr);
+  assert(blob_size != nullptr);
+
+  // Do compression before taking the partition mutex so large-value CPU work
+  // does not serialize writers. A concurrent file rollover can still cause
+  // this compressed buffer to be discarded below, which is acceptable on this
+  // non-hot failure/configuration-change path.
+  GrowableBuffer compressed_value;
+  Slice write_value = value;
+  if (compression != kNoCompression) {
+    auto& compression_state =
+        GetDirectWriteCompressionState(compression, settings.compression_opts);
+    if (compression_state.compressor == nullptr) {
+      return Status::NotSupported(
+          "Blob direct write compression type not supported");
+    }
+    Status s = LegacyForceBuiltinCompression(*compression_state.compressor,
+                                             &compression_state.working_area,
+                                             value, &compressed_value);
+    if (!s.ok()) {
+      return s;
+    }
+    write_value = Slice(compressed_value);
+  }
+
+  // Partition selection is based on the logical write inputs. In particular,
+  // strategies that inspect value contents or size see the original
+  // uncompressed value rather than `write_value`. The modulo here is
+  // intentional so custom strategies can return arbitrary hashed or sentinel
+  // values without violating the partition bounds.
+  const uint32_t selected_partition_idx =
+      partition_idx != nullptr
+          ? (*partition_idx % num_partitions_)
+          : (strategy_->SelectPartition(num_partitions_, column_family_id, key,
+                                        value) %
+             num_partitions_);
+
+  {
+    MutexLock lock(&mutex_);
+    Partition* partition = partitions_[selected_partition_idx].get();
+
+    auto seal_current_file = [&]() -> Status {
+      if (!partition->writer) {
+        return Status::OK();
+      }
+      SealedFile sealed_file;
+      Status s = SealActiveBlobFile(write_options, partition, &sealed_file);
+      if (s.ok()) {
+        current_generation_sealed_files_.push_back(std::move(sealed_file));
+      }
+      return s;
+    };
+
+    const uint64_t record_size =
+        BlobLogRecord::kHeaderSize + key.size() + write_value.size();
+    const uint64_t future_file_size =
+        partition->file_size + record_size + BlobLogFooter::kSize;
+
+    if (partition->writer &&
+        (partition->column_family_id != column_family_id ||
+         partition->compression != compression ||
+         (partition->blob_count > 0 && future_file_size > blob_file_size_))) {
+      Status s = seal_current_file();
+      if (!s.ok()) {
+        return s;
+      }
+    }
+
+    if (!partition->writer) {
+      Status s = OpenNewBlobFile(partition, column_family_id, compression,
+                                 selected_partition_idx);
+      if (!s.ok()) {
+        return s;
+      }
+    }
+
+    uint64_t key_offset = 0;
+    Status s = partition->writer->AddRecord(write_options, key, write_value,
+                                            &key_offset, blob_offset);
+    if (!s.ok()) {
+      return s;
+    }
+
+    partition->sync_required = true;
+    partition->blob_count += 1;
+    partition->total_blob_bytes += record_size;
+    partition->file_size = BlobLogHeader::kSize + partition->total_blob_bytes;
+
+    *blob_file_number = partition->file_number;
+    *blob_size = write_value.size();
+  }
+
+  Status prepopulate_s = MaybePrepopulateBlobCache(
+      settings, value, *blob_file_number, *blob_offset);
+  if (!prepopulate_s.ok() && info_log_ != nullptr) {
+    ROCKS_LOG_WARN(info_log_,
+                   "Failed to pre-populate direct-write blob cache entry: %s",
+                   prepopulate_s.ToString().c_str());
+  }
+
+  return Status::OK();
+}
+
+void BlobFilePartitionManager::RotateCurrentGeneration() {
+  MutexLock lock(&mutex_);
+
+  GenerationBatch batch;
+  batch.sealed_files = std::move(current_generation_sealed_files_);
+  current_generation_sealed_files_.clear();
+
+  for (auto& partition : partitions_) {
+    if (!partition->writer) {
+      continue;
+    }
+
+    DeferredFile deferred;
+    deferred.writer = std::move(partition->writer);
+    deferred.file_number = partition->file_number;
+    deferred.blob_count = partition->blob_count;
+    deferred.total_blob_bytes = partition->total_blob_bytes;
+    deferred.garbage_blob_count = partition->garbage_blob_count;
+    deferred.garbage_blob_bytes = partition->garbage_blob_bytes;
+    ResetPartitionState(partition.get());
+    batch.deferred_files.emplace_back(std::move(deferred));
+  }
+
+  pending_generations_.emplace_back(std::move(batch));
+}
+
+Status BlobFilePartitionManager::PrepareFlushAdditions(
+    const WriteOptions& write_options, size_t num_generations,
+    std::vector<BlobFileAddition>* additions,
+    std::vector<BlobFileGarbage>* garbages,
+    std::vector<std::vector<uint64_t>>* generation_blob_file_numbers) {
+  assert(additions != nullptr);
+  assert(garbages != nullptr);
+  additions->clear();
+  garbages->clear();
+  if (generation_blob_file_numbers != nullptr) {
+    generation_blob_file_numbers->clear();
+  }
+
+  MutexLock lock(&mutex_);
+  if (num_generations > pending_generations_.size()) {
+    return Status::Corruption(
+        "Missing blob direct write generation metadata for flush");
+  }
+
+  for (size_t i = 0; i < num_generations; ++i) {
+    GenerationBatch& batch = pending_generations_[i];
+    while (!batch.deferred_files.empty()) {
+      DeferredFile deferred = std::move(batch.deferred_files.front());
+      batch.deferred_files.pop_front();
+
+      SealedFile sealed_file;
+      Status s = SealDeferredFile(write_options, &deferred, &sealed_file);
+      if (!s.ok()) {
+        return s;
+      }
+      // Keep each successfully sealed file attached to the generation
+      // immediately. If a later seal or the flush job itself fails, retry must
+      // reuse these exact on-disk files instead of finalizing replacements.
+      batch.sealed_files.push_back(std::move(sealed_file));
+    }
+
+    std::vector<uint64_t>* generation_file_numbers = nullptr;
+    if (generation_blob_file_numbers != nullptr) {
+      generation_blob_file_numbers->emplace_back();
+      generation_file_numbers = &generation_blob_file_numbers->back();
+      generation_file_numbers->reserve(batch.sealed_files.size());
+    }
+
+    for (const auto& sealed_file : batch.sealed_files) {
+      additions->push_back(sealed_file.addition);
+      AddSealedFileGarbage(sealed_file, garbages);
+      if (generation_file_numbers != nullptr) {
+        generation_file_numbers->push_back(
+            sealed_file.addition.GetBlobFileNumber());
+      }
+    }
+  }
+
+  return Status::OK();
+}
+
+Status BlobFilePartitionManager::MarkBlobWriteAsGarbage(uint64_t file_number,
+                                                        uint64_t blob_count,
+                                                        uint64_t blob_bytes) {
+  if (blob_count == 0) {
+    assert(blob_bytes == 0);
+    return Status::OK();
+  }
+
+  MutexLock lock(&mutex_);
+  for (auto& partition : partitions_) {
+    if (MarkPartitionGarbage(partition.get(), file_number, blob_count,
+                             blob_bytes)) {
+      return Status::OK();
+    }
+  }
+
+  if (MarkSealedFileGarbage(&current_generation_sealed_files_, file_number,
+                            blob_count, blob_bytes)) {
+    return Status::OK();
+  }
+
+  for (auto& batch : pending_generations_) {
+    for (auto& deferred : batch.deferred_files) {
+      if (MarkDeferredFileGarbage(&deferred, file_number, blob_count,
+                                  blob_bytes)) {
+        return Status::OK();
+      }
+    }
+    if (MarkSealedFileGarbage(&batch.sealed_files, file_number, blob_count,
+                              blob_bytes)) {
+      return Status::OK();
+    }
+  }
+
+  const std::string message =
+      "Could not match failed blob direct-write rollback for file #" +
+      std::to_string(file_number);
+  if (info_log_ != nullptr) {
+    ROCKS_LOG_ERROR(info_log_, "%s", message.c_str());
+  }
+  return Status::Corruption(message);
+}
+
+void BlobFilePartitionManager::CommitPreparedGenerations(
+    size_t num_generations) {
+  MutexLock lock(&mutex_);
+  while (num_generations-- > 0 && !pending_generations_.empty()) {
+    pending_generations_.pop_front();
+  }
+}
+
+Status BlobFilePartitionManager::SyncAllOpenFiles(
+    const WriteOptions& write_options) {
+  MutexLock lock(&mutex_);
+  for (const auto& partition : partitions_) {
+    if (!partition->writer || !partition->sync_required) {
+      continue;
+    }
+    Status s = partition->writer->Sync(write_options);
+    if (!s.ok()) {
+      return s;
+    }
+    partition->sync_required = false;
+  }
+  return Status::OK();
+}
+
+void BlobFilePartitionManager::GetActiveBlobFileNumbers(
+    UnorderedSet<uint64_t>* file_numbers) const {
+  assert(file_numbers != nullptr);
+  ReadLock lock(&file_partition_mutex_);
+  for (const auto& entry : file_to_partition_) {
+    file_numbers->insert(entry.first);
+  }
+}
+
+void BlobFilePartitionManager::GetProtectedBlobFileNumbers(
+    UnorderedSet<uint64_t>* file_numbers) const {
+  assert(file_numbers != nullptr);
+  ReadLock lock(&file_partition_mutex_);
+  for (const auto& entry : protected_blob_file_refs_) {
+    file_numbers->insert(entry.first);
+  }
+}
+
+bool BlobFilePartitionManager::IsTrackedBlobFileNumber(
+    uint64_t file_number) const {
+  ReadLock lock(&file_partition_mutex_);
+  return file_to_partition_.find(file_number) != file_to_partition_.end() ||
+         protected_blob_file_refs_.find(file_number) !=
+             protected_blob_file_refs_.end();
+}
+
+void BlobFilePartitionManager::ProtectSealedBlobFileNumbers(
+    const std::vector<uint64_t>& file_numbers) {
+  if (file_numbers.empty()) {
+    return;
+  }
+
+  WriteLock lock(&file_partition_mutex_);
+  for (uint64_t file_number : file_numbers) {
+    ++protected_blob_file_refs_[file_number];
+  }
+}
+
+void BlobFilePartitionManager::UnprotectSealedBlobFileNumbers(
+    const std::vector<uint64_t>& file_numbers) {
+  if (file_numbers.empty()) {
+    return;
+  }
+
+  WriteLock lock(&file_partition_mutex_);
+  for (uint64_t file_number : file_numbers) {
+    auto it = protected_blob_file_refs_.find(file_number);
+    if (it == protected_blob_file_refs_.end()) {
+      if (info_log_ != nullptr) {
+        ROCKS_LOG_ERROR(info_log_,
+                        "Memtable blob protection underflow for file #%" PRIu64,
+                        file_number);
+      }
+      continue;
+    }
+
+    assert(it->second > 0);
+    --it->second;
+    if (it->second == 0) {
+      protected_blob_file_refs_.erase(it);
+      if (blob_file_cache_ != nullptr) {
+        // Once the last memtable-backed reference goes away, any cached reader
+        // for this file is either obsolete or can be reopened through the
+        // manifest-visible path. Evict it here so delayed protection does not
+        // leave an obsolete blob reader behind until DB close.
+        blob_file_cache_->Evict(file_number);
+      }
+    }
+  }
+}
+
+void BlobFilePartitionManager::RemoveFilePartitionMappings(
+    const std::vector<uint64_t>& file_numbers) {
+  if (file_numbers.empty()) {
+    return;
+  }
+
+  WriteLock lock(&file_partition_mutex_);
+  for (uint64_t file_number : file_numbers) {
+    file_to_partition_.erase(file_number);
+    if (blob_file_cache_ != nullptr) {
+      // In-flight direct-write reads may have cached a footer-less reader for
+      // this file before it was sealed. Drop it now so future manifest-visible
+      // reads reopen against the finalized on-disk size and footer state.
+      blob_file_cache_->Evict(file_number);
+    }
+  }
+}
+
+Status BlobFilePartitionManager::ResolveBlobDirectWriteIndex(
+    const ReadOptions& read_options, const Slice& user_key,
+    const BlobIndex& blob_idx, const Version* version,
+    BlobFileCache* blob_file_cache, FilePrefetchBuffer* prefetch_buffer,
+    PinnableSlice* blob_value, uint64_t* bytes_read) {
+  assert(blob_value != nullptr);
+
+  if (version != nullptr) {
+    // Only fall back when the blob file is still owned exclusively by the
+    // write path and therefore absent from Version metadata. Once Version
+    // knows the file number, every result from Version::GetBlob(), including
+    // corruption, must propagate directly.
+    if (blob_idx.HasTTL() || blob_idx.IsInlined() ||
+        version->storage_info()->GetBlobFileMetaData(blob_idx.file_number()) !=
+            nullptr) {
+      return version->GetBlob(read_options, user_key, blob_idx, prefetch_buffer,
+                              blob_value, bytes_read);
+    }
+  }
+
+  if (blob_file_cache == nullptr) {
+    return version != nullptr ? Status::Corruption("Invalid blob file number")
+                              : Status::NotFound();
+  }
+
+  if (read_options.read_tier == kBlockCacheTier) {
+    // The direct-write fallback below may need to open the blob file reader,
+    // which `kBlockCacheTier` forbids. Keep the normal Version-backed path
+    // above eligible for cache-only hits.
+    return Status::Incomplete("Cannot read blob(s): no disk I/O allowed");
+  }
+
+  Status s;
+  CacheHandleGuard<BlobFileReader> reader;
+  s = blob_file_cache->GetBlobFileReader(read_options, blob_idx.file_number(),
+                                         &reader,
+                                         /*allow_footer_skip_retry=*/true);
+  if (!s.ok()) {
+    return s;
+  }
+
+  std::unique_ptr<BlobContents> blob_contents;
+  s = reader.GetValue()->GetBlob(read_options, user_key, blob_idx.offset(),
+                                 blob_idx.size(), blob_idx.compression(),
+                                 prefetch_buffer, nullptr, &blob_contents,
+                                 bytes_read);
+  if (s.ok()) {
+    blob_value->PinSelf(blob_contents->data());
+    return s;
+  }
+
+  if (!s.IsCorruption()) {
+    return s;
+  }
+
+  reader.Reset();
+  blob_file_cache->Evict(blob_idx.file_number());
+
+  std::unique_ptr<BlobFileReader> fresh_reader;
+  s = blob_file_cache->OpenBlobFileReaderUncached(
+      read_options, blob_idx.file_number(), &fresh_reader,
+      /*allow_footer_skip_retry=*/true);
+  if (!s.ok()) {
+    return s;
+  }
+
+  std::unique_ptr<BlobContents> fresh_contents;
+  s = fresh_reader->GetBlob(read_options, user_key, blob_idx.offset(),
+                            blob_idx.size(), blob_idx.compression(),
+                            prefetch_buffer, nullptr, &fresh_contents,
+                            bytes_read);
+  if (s.ok()) {
+    blob_value->PinSelf(fresh_contents->data());
+    CacheHandleGuard<BlobFileReader> ignored;
+    blob_file_cache
+        ->RefreshBlobFileReader(blob_idx.file_number(), &fresh_reader, &ignored)
+        .PermitUncheckedError();
+  }
+
+  return s;
+}
+
+}  // namespace ROCKSDB_NAMESPACE

db/blob/blob_file_partition_manager.h

@@ -0,0 +1,294 @@
+//  Copyright (c) Meta Platforms, Inc. and affiliates.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+#pragma once
+
+#include <cstdint>
+#include <deque>
+#include <functional>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "db/blob/blob_file_addition.h"
+#include "db/blob/blob_file_garbage.h"
+#include "db/blob/blob_log_format.h"
+#include "db/blob/blob_write_batch_transformer.h"
+#include "port/port.h"
+#include "rocksdb/compression_type.h"
+#include "rocksdb/env.h"
+#include "rocksdb/file_system.h"
+#include "rocksdb/options.h"
+#include "rocksdb/rocksdb_namespace.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/status.h"
+#include "util/hash_containers.h"
+namespace ROCKSDB_NAMESPACE {
+
+class BlobFileCache;
+class BlobFileCompletionCallback;
+class BlobIndex;
+class BlobLogWriter;
+class FilePrefetchBuffer;
+class IOTracer;
+class Logger;
+class PinnableSlice;
+class Version;
+class WritableFileWriter;
+struct FileOptions;
+struct ReadOptions;
+
+// Manages per-partition blob files for write-path blob direct write.
+//
+// The v1 design keeps each memtable switch as one FIFO generation batch.
+// Direct-write files for that memtable are sealed and registered when the
+// matching flush commits. The current implementation still serializes blob
+// appends through one manager mutex; follow-up PRs can add independent
+// per-partition locks to allow concurrent blob writes without changing the
+// generation/flush contract. Follow-up PRs can also broaden compatibility as
+// the feature matures.
+class BlobFilePartitionManager {
+ public:
+  using FileNumberAllocator = std::function<uint64_t()>;
+
+  // Creates the per-column-family manager for write-path blob files.
+  BlobFilePartitionManager(
+      uint32_t num_partitions,
+      std::shared_ptr<BlobFilePartitionStrategy> strategy,
+      FileNumberAllocator file_number_allocator, FileSystem* fs,
+      SystemClock* clock, Statistics* statistics,
+      const FileOptions& file_options, std::string db_path,
+      std::string column_family_name, uint64_t blob_file_size, bool use_fsync,
+      BlobFileCache* blob_file_cache, BlobFileCompletionCallback* blob_callback,
+      const std::vector<std::shared_ptr<EventListener>>& listeners,
+      FileChecksumGenFactory* file_checksum_gen_factory,
+      const FileTypeSet& checksum_handoff_file_types,
+      const std::shared_ptr<IOTracer>& io_tracer, std::string db_id,
+      std::string db_session_id, Logger* info_log);
+
+  // Evicts cached readers for manager-owned files during shutdown.
+  ~BlobFilePartitionManager();
+
+  // Appends one blob record to a partition file and returns the resulting
+  // BlobIndex location metadata.
+  Status WriteBlob(const WriteOptions& write_options, uint32_t column_family_id,
+                   CompressionType compression, const Slice& key,
+                   const Slice& value, uint64_t* blob_file_number,
+                   uint64_t* blob_offset, uint64_t* blob_size,
+                   const BlobDirectWriteSettings& settings,
+                   const uint32_t* partition_idx = nullptr);
+
+  // Selects the partition to use for all blob-backed columns of one PutEntity
+  // operation. The return value is already normalized to [0, num_partitions_).
+  uint32_t SelectWideColumnPartition(uint32_t column_family_id,
+                                     const Slice& key,
+                                     const WideColumns& columns) const;
+
+  // Move the current active partition files into the next immutable
+  // memtable-generation batch. Called from SwitchMemtable() while DB mutex is
+  // held. No I/O is performed here.
+  void RotateCurrentGeneration();
+
+  // Seal the first `num_generations` queued immutable generations and return
+  // all blob additions and initial-garbage updates that must be registered
+  // with the matching flush. Generations stay queued until
+  // CommitPreparedGenerations() is called. If `generation_blob_file_numbers`
+  // is non-null, it receives the sealed blob file numbers for each prepared
+  // generation in the same FIFO order.
+  Status PrepareFlushAdditions(const WriteOptions& write_options,
+                               size_t num_generations,
+                               std::vector<BlobFileAddition>* additions,
+                               std::vector<BlobFileGarbage>* garbages,
+                               std::vector<std::vector<uint64_t>>*
+                                   generation_blob_file_numbers = nullptr);
+
+  // Remove the first `num_generations` prepared immutable generations after
+  // their blob-file additions and garbage edits were committed to MANIFEST.
+  void CommitPreparedGenerations(size_t num_generations);
+
+  // In v1 flush-on-write mode each AddRecord flushes to the OS immediately, so
+  // there is nothing extra to do for the non-sync write path.
+  Status FlushAllOpenFiles(const WriteOptions& /*write_options*/) {
+    return Status::OK();
+  }
+
+  // Sync the active open blob files before a sync WAL write.
+  Status SyncAllOpenFiles(const WriteOptions& write_options);
+
+  // Returns blob files still owned by the manager and therefore not yet safe
+  // to consider obsolete.
+  void GetActiveBlobFileNumbers(UnorderedSet<uint64_t>* file_numbers) const;
+
+  // Returns sealed blob files that are still reachable through live memtables
+  // or old SuperVersions and therefore must not be purged yet.
+  void GetProtectedBlobFileNumbers(UnorderedSet<uint64_t>* file_numbers) const;
+
+  // Returns true when the blob file is still owned by the write path or
+  // protected by a live memtable / old SuperVersion.
+  bool IsTrackedBlobFileNumber(uint64_t file_number) const;
+
+  // Increments / decrements memtable-held protection on sealed blob files.
+  void ProtectSealedBlobFileNumbers(const std::vector<uint64_t>& file_numbers);
+  void UnprotectSealedBlobFileNumbers(
+      const std::vector<uint64_t>& file_numbers);
+
+  // Stops protecting file numbers that are now registered in MANIFEST.
+  void RemoveFilePartitionMappings(const std::vector<uint64_t>& file_numbers);
+
+  // Marks blob records from a failed transformed write as initial garbage for
+  // the target blob file while keeping the physical bytes in place.
+  // Returns Corruption if the manager can no longer match the blob file.
+  Status MarkBlobWriteAsGarbage(uint64_t file_number, uint64_t blob_count,
+                                uint64_t blob_bytes);
+
+  // Resolves a direct-write BlobIndex by consulting manifest-visible state
+  // first, then falling back to direct blob-file reads only when the target
+  // blob file is still write-path-owned and therefore not yet tracked by
+  // Version. Existing manifest-visible read results, including I/O failures,
+  // are returned directly rather than masked by fallback logic.
+  static Status ResolveBlobDirectWriteIndex(
+      const ReadOptions& read_options, const Slice& user_key,
+      const BlobIndex& blob_idx, const Version* version,
+      BlobFileCache* blob_file_cache, FilePrefetchBuffer* prefetch_buffer,
+      PinnableSlice* blob_value, uint64_t* bytes_read);
+
+ private:
+  struct Partition {
+    // Active writer for this partition, or null when the partition is idle.
+    std::unique_ptr<BlobLogWriter> writer;
+    // Metadata tracked while the active file remains open.
+    uint64_t file_number = 0;
+    uint64_t file_size = 0;
+    uint64_t blob_count = 0;
+    uint64_t total_blob_bytes = 0;
+    // Failed transformed writes already appended to this physical file.
+    uint64_t garbage_blob_count = 0;
+    uint64_t garbage_blob_bytes = 0;
+    uint32_t column_family_id = 0;
+    CompressionType compression = kNoCompression;
+    bool sync_required = false;
+  };
+
+  struct DeferredFile {
+    // Blob writer moved out of an active partition at memtable rotation.
+    std::unique_ptr<BlobLogWriter> writer;
+    // Metadata preserved until flush preparation seals the file.
+    uint64_t file_number = 0;
+    uint64_t blob_count = 0;
+    uint64_t total_blob_bytes = 0;
+    // Failed transformed writes already appended before the file is sealed.
+    uint64_t garbage_blob_count = 0;
+    uint64_t garbage_blob_bytes = 0;
+  };
+
+  struct SealedFile {
+    // Blob-file metadata ready to be added to MANIFEST.
+    BlobFileAddition addition;
+    // Initial unreachable bytes that should be registered as garbage
+    // alongside the file addition.
+    uint64_t garbage_blob_count = 0;
+    uint64_t garbage_blob_bytes = 0;
+  };
+
+  struct GenerationBatch {
+    // Files that were still open when the memtable became immutable.
+    std::deque<DeferredFile> deferred_files;
+    // Files already sealed for this memtable generation.
+    std::vector<SealedFile> sealed_files;
+  };
+
+  // Clears all active-file bookkeeping from a partition after sealing.
+  void ResetPartitionState(Partition* partition);
+  // Marks a blob file as manager-owned until it is committed or abandoned.
+  void AddFilePartitionMapping(uint64_t file_number, uint32_t partition_idx);
+  // Stops tracking a blob file after open/seal failure.
+  void RemoveFilePartitionMapping(uint64_t file_number);
+
+  // Opens a new active blob file for one partition.
+  Status OpenNewBlobFile(Partition* partition, uint32_t column_family_id,
+                         CompressionType compression, uint32_t partition_idx);
+  // Finalizes one active partition file and returns the MANIFEST addition.
+  Status SealActiveBlobFile(const WriteOptions& write_options,
+                            Partition* partition, SealedFile* sealed_file);
+  // Finalizes one deferred file that was carried over to flush preparation.
+  Status SealDeferredFile(const WriteOptions& write_options,
+                          DeferredFile* deferred, SealedFile* sealed_file);
+  // Appends the footer, reports file completion, and builds the resulting
+  // BlobFileAddition for one sealed blob file.
+  Status FinalizeBlobFile(const WriteOptions& write_options,
+                          BlobLogWriter* writer, uint64_t file_number,
+                          uint64_t blob_count, uint64_t total_blob_bytes,
+                          BlobFileAddition* addition);
+  // Appends one initial-garbage record to the flush output if any failed
+  // transformed writes targeted the sealed blob file.
+  static void AddSealedFileGarbage(const SealedFile& sealed_file,
+                                   std::vector<BlobFileGarbage>* garbages);
+  // Returns true if the active open file matches `file_number` and consumes
+  // the failed-write garbage accounting.
+  static bool MarkPartitionGarbage(Partition* partition, uint64_t file_number,
+                                   uint64_t blob_count, uint64_t blob_bytes);
+  // Returns true if the deferred flush-preparation file matches `file_number`
+  // and consumes the failed-write garbage accounting.
+  static bool MarkDeferredFileGarbage(DeferredFile* deferred,
+                                      uint64_t file_number, uint64_t blob_count,
+                                      uint64_t blob_bytes);
+  // Returns true if one already-sealed file matches `file_number` and
+  // consumes the failed-write garbage accounting.
+  static bool MarkSealedFileGarbage(std::vector<SealedFile>* sealed_files,
+                                    uint64_t file_number, uint64_t blob_count,
+                                    uint64_t blob_bytes);
+  // Seeds the blob cache with the original uncompressed value when configured.
+  Status MaybePrepopulateBlobCache(const BlobDirectWriteSettings& settings,
+                                   const Slice& original_value,
+                                   uint64_t blob_file_number,
+                                   uint64_t blob_offset);
+
+  // Configured partition fanout and write-selection strategy.
+  const uint32_t num_partitions_;
+  std::shared_ptr<BlobFilePartitionStrategy> strategy_;
+  // Shared services needed to create, track, and cache blob files.
+  FileNumberAllocator file_number_allocator_;
+  FileSystem* fs_;
+  SystemClock* clock_;
+  Statistics* statistics_;
+  FileOptions file_options_;
+  // Column-family context used for file naming and callbacks.
+  std::string db_path_;
+  std::string column_family_name_;
+  // File creation policy and shared blob-file infrastructure.
+  uint64_t blob_file_size_;
+  bool use_fsync_;
+  BlobFileCache* blob_file_cache_;
+  BlobFileCompletionCallback* blob_callback_;
+  std::vector<std::shared_ptr<EventListener>> listeners_;
+  FileChecksumGenFactory* file_checksum_gen_factory_;
+  FileTypeSet checksum_handoff_file_types_;
+  std::shared_ptr<IOTracer> io_tracer_;
+  // DB identity used when constructing cache keys.
+  std::string db_id_;
+  std::string db_session_id_;
+  Logger* info_log_;
+
+  // One active writer slot per configured partition.
+  std::vector<std::unique_ptr<Partition>> partitions_;
+
+  // Protects partition state and generation queues.
+  mutable port::Mutex mutex_;
+  // Files already sealed while the current mutable memtable was active.
+  std::vector<SealedFile> current_generation_sealed_files_;
+  // FIFO immutable memtable generations waiting to be flushed.
+  std::deque<GenerationBatch> pending_generations_;
+
+  // Tracks blob files still owned by active or deferred write-path state until
+  // MANIFEST commit publishes them.
+  std::unordered_map<uint64_t, uint32_t> file_to_partition_;
+  // Sealed direct-write files that remain reachable from live memtables, such
+  // as old SuperVersions serving lazy iterator reads after flush commit.
+  std::unordered_map<uint64_t, uint32_t> protected_blob_file_refs_;
+  // Protects file_to_partition_ and protected_blob_file_refs_.
+  mutable port::RWMutex file_partition_mutex_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE

db/blob/blob_file_reader.cc

@@ -17,10 +17,10 @@
 #include "rocksdb/file_system.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/status.h"
+#include "table/format.h"
 #include "table/multiget_context.h"
 #include "test_util/sync_point.h"
 #include "util/compression.h"
-#include "util/crc32c.h"
 #include "util/stop_watch.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -29,7 +29,7 @@ Status BlobFileReader::Create(
     const ImmutableOptions& immutable_options, const ReadOptions& read_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 std::shared_ptr<IOTracer>& io_tracer, bool skip_footer_validation,
     std::unique_ptr<BlobFileReader>* blob_file_reader) {
   assert(blob_file_reader);
   assert(!*blob_file_reader);
@@ -40,7 +40,8 @@ Status BlobFileReader::Create(
   {
     const Status s =
         OpenFile(immutable_options, file_options, blob_file_read_hist,
-                 blob_file_number, io_tracer, &file_size, &file_reader);
+                 blob_file_number, io_tracer, &file_size, &file_reader,
+                 /*skip_footer_size_check=*/skip_footer_validation);
     if (!s.ok()) {
       return s;
     }
@@ -61,7 +62,7 @@ Status BlobFileReader::Create(
     }
   }
 
-  {
+  if (!skip_footer_validation) {
     const Status s =
         ReadFooter(file_reader.get(), read_options, file_size, statistics);
     if (!s.ok()) {
@@ -69,9 +70,17 @@ Status BlobFileReader::Create(
     }
   }
 
+  std::shared_ptr<Decompressor> decompressor;
+  if (compression_type != kNoCompression) {
+    // The blob format has always used compression format 2
+    decompressor = GetBuiltinV2CompressionManager()->GetDecompressorOptimizeFor(
+        compression_type);
+  }
+
   blob_file_reader->reset(
       new BlobFileReader(std::move(file_reader), file_size, compression_type,
-                         immutable_options.clock, statistics));
+                         std::move(decompressor), immutable_options.clock,
+                         statistics, !skip_footer_validation));
 
   return Status::OK();
 }
@@ -80,7 +89,8 @@ Status BlobFileReader::OpenFile(
     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) {
+    std::unique_ptr<RandomAccessFileReader>* file_reader,
+    bool skip_footer_size_check) {
   assert(file_size);
   assert(file_reader);
 
@@ -105,17 +115,26 @@ Status BlobFileReader::OpenFile(
     }
   }
 
-  if (*file_size < BlobLogHeader::kSize + BlobLogFooter::kSize) {
+  if (!skip_footer_size_check &&
+      *file_size < BlobLogHeader::kSize + BlobLogFooter::kSize) {
+    return Status::Corruption("Malformed blob file");
+  }
+  if (skip_footer_size_check && *file_size < BlobLogHeader::kSize) {
     return Status::Corruption("Malformed blob file");
   }
 
   std::unique_ptr<FSRandomAccessFile> file;
+  FileOptions reader_file_opts = file_opts;
+
+  if (skip_footer_size_check && reader_file_opts.use_direct_reads) {
+    reader_file_opts.use_direct_reads = false;
+  }
 
   {
     TEST_SYNC_POINT("BlobFileReader::OpenFile:NewRandomAccessFile");
 
     const Status s =
-        fs->NewRandomAccessFile(blob_file_path, file_opts, &file, dbg);
+        fs->NewRandomAccessFile(blob_file_path, reader_file_opts, &file, dbg);
     if (!s.ok()) {
       return s;
     }
@@ -250,7 +269,8 @@ Status BlobFileReader::ReadFromFile(const RandomAccessFileReader* file_reader,
   Status s;
 
   IOOptions io_options;
-  s = file_reader->PrepareIOOptions(read_options, io_options);
+  IODebugContext dbg;
+  s = file_reader->PrepareIOOptions(read_options, io_options, &dbg);
   if (!s.ok()) {
     return s;
   }
@@ -259,13 +279,13 @@ Status BlobFileReader::ReadFromFile(const RandomAccessFileReader* file_reader,
     constexpr char* scratch = nullptr;
 
     s = file_reader->Read(io_options, read_offset, read_size, slice, scratch,
-                          aligned_buf);
+                          aligned_buf, &dbg);
   } else {
     buf->reset(new char[read_size]);
     constexpr AlignedBuf* aligned_scratch = nullptr;
 
     s = file_reader->Read(io_options, read_offset, read_size, slice, buf->get(),
-                          aligned_scratch);
+                          aligned_scratch, &dbg);
   }
 
   if (!s.ok()) {
@@ -281,13 +301,16 @@ Status BlobFileReader::ReadFromFile(const RandomAccessFileReader* file_reader,
 
 BlobFileReader::BlobFileReader(
     std::unique_ptr<RandomAccessFileReader>&& file_reader, uint64_t file_size,
-    CompressionType compression_type, SystemClock* clock,
-    Statistics* statistics)
+    CompressionType compression_type,
+    std::shared_ptr<Decompressor> decompressor, SystemClock* clock,
+    Statistics* statistics, bool has_footer)
     : file_reader_(std::move(file_reader)),
       file_size_(file_size),
       compression_type_(compression_type),
+      decompressor_(std::move(decompressor)),
       clock_(clock),
-      statistics_(statistics) {
+      statistics_(statistics),
+      has_footer_(has_footer) {
   assert(file_reader_);
 }
 
@@ -302,7 +325,8 @@ Status BlobFileReader::GetBlob(
 
   const uint64_t key_size = user_key.size();
 
-  if (!IsValidBlobOffset(offset, key_size, value_size, file_size_)) {
+  if (!IsValidBlobOffset(offset, key_size, value_size, file_size_,
+                         has_footer_)) {
     return Status::Corruption("Invalid blob offset");
   }
 
@@ -334,7 +358,8 @@ Status BlobFileReader::GetBlob(
     constexpr bool for_compaction = true;
 
     IOOptions io_options;
-    s = file_reader_->PrepareIOOptions(read_options, io_options);
+    IODebugContext dbg;
+    s = file_reader_->PrepareIOOptions(read_options, io_options, &dbg);
     if (!s.ok()) {
       return s;
     }
@@ -373,8 +398,9 @@ Status BlobFileReader::GetBlob(
   const Slice value_slice(record_slice.data() + adjustment, value_size);
 
   {
-    const Status s = UncompressBlobIfNeeded(
-        value_slice, compression_type, allocator, clock_, statistics_, result);
+    const Status s = UncompressBlobIfNeeded(value_slice, compression_type,
+                                            decompressor_.get(), allocator,
+                                            clock_, statistics_, result);
     if (!s.ok()) {
       return s;
     }
@@ -416,7 +442,8 @@ void BlobFileReader::MultiGetBlob(
     const uint64_t offset = req->offset;
     const uint64_t value_size = req->len;
 
-    if (!IsValidBlobOffset(offset, key_size, value_size, file_size_)) {
+    if (!IsValidBlobOffset(offset, key_size, value_size, file_size_,
+                           has_footer_)) {
       *req->status = Status::Corruption("Invalid blob offset");
       continue;
     }
@@ -442,6 +469,13 @@ void BlobFileReader::MultiGetBlob(
 
   RecordTick(statistics_, BLOB_DB_BLOB_FILE_BYTES_READ, total_len);
 
+  if (read_reqs.empty()) {
+    if (bytes_read) {
+      *bytes_read = 0;
+    }
+    return;
+  }
+
   Buffer buf;
   AlignedBuf aligned_buf;
 
@@ -463,10 +497,11 @@ void BlobFileReader::MultiGetBlob(
   PERF_COUNTER_ADD(blob_read_count, num_blobs);
   PERF_COUNTER_ADD(blob_read_byte, total_len);
   IOOptions opts;
-  s = file_reader_->PrepareIOOptions(read_options, opts);
+  IODebugContext dbg;
+  s = file_reader_->PrepareIOOptions(read_options, opts, &dbg);
   if (s.ok()) {
     s = file_reader_->MultiRead(opts, read_reqs.data(), read_reqs.size(),
-                                direct_io ? &aligned_buf : nullptr);
+                                direct_io ? &aligned_buf : nullptr, &dbg);
   }
   if (!s.ok()) {
     for (auto& req : read_reqs) {
@@ -520,10 +555,10 @@ void BlobFileReader::MultiGetBlob(
     }
 
     // Uncompress blob if needed
-    Slice value_slice(record_slice.data() + adjustments[i], req->len);
-    *req->status =
-        UncompressBlobIfNeeded(value_slice, compression_type_, allocator,
-                               clock_, statistics_, &blob_reqs[i].second);
+    Slice value_slice(record_slice.data() + adjustments[j - 1], req->len);
+    *req->status = UncompressBlobIfNeeded(
+        value_slice, compression_type_, decompressor_.get(), allocator, clock_,
+        statistics_, &blob_reqs[i].second);
     if (req->status->ok()) {
       total_bytes += record_slice.size();
     }
@@ -580,8 +615,8 @@ Status BlobFileReader::VerifyBlob(const Slice& record_slice,
 
 Status BlobFileReader::UncompressBlobIfNeeded(
     const Slice& value_slice, CompressionType compression_type,
-    MemoryAllocator* allocator, SystemClock* clock, Statistics* statistics,
-    std::unique_ptr<BlobContents>* result) {
+    Decompressor* decompressor, MemoryAllocator* allocator, SystemClock* clock,
+    Statistics* statistics, std::unique_ptr<BlobContents>* result) {
   assert(result);
 
   if (compression_type == kNoCompression) {
@@ -590,31 +625,33 @@ Status BlobFileReader::UncompressBlobIfNeeded(
     return Status::OK();
   }
 
-  UncompressionContext context(compression_type);
-  UncompressionInfo info(context, UncompressionDict::GetEmptyDict(),
-                         compression_type);
+  assert(decompressor);
 
-  size_t uncompressed_size = 0;
-  constexpr uint32_t compression_format_version = 2;
+  Decompressor::Args args;
+  args.compression_type = compression_type;
+  args.compressed_data = value_slice;
 
-  CacheAllocationPtr output;
+  Status s = decompressor->ExtractUncompressedSize(args);
+  if (!s.ok()) {
+    return Status::Corruption(s.ToString());
+  }
+
+  CacheAllocationPtr output = AllocateBlock(args.uncompressed_size, allocator);
 
   {
     PERF_TIMER_GUARD(blob_decompress_time);
     StopWatch stop_watch(clock, statistics, BLOB_DB_DECOMPRESSION_MICROS);
-    output = UncompressData(info, value_slice.data(), value_slice.size(),
-                            &uncompressed_size, compression_format_version,
-                            allocator);
+    s = decompressor->DecompressBlock(args, output.get());
   }
 
   TEST_SYNC_POINT_CALLBACK(
-      "BlobFileReader::UncompressBlobIfNeeded:TamperWithResult", &output);
+      "BlobFileReader::UncompressBlobIfNeeded:TamperWithResult", &s);
 
-  if (!output) {
-    return Status::Corruption("Unable to uncompress blob");
+  if (!s.ok()) {
+    return Status::Corruption(s.ToString());
   }
 
-  result->reset(new BlobContents(std::move(output), uncompressed_size));
+  result->reset(new BlobContents(std::move(output), args.uncompressed_size));
 
   return Status::OK();
 }

db/blob/blob_file_reader.h

@@ -10,6 +10,7 @@
 
 #include "db/blob/blob_read_request.h"
 #include "file/random_access_file_reader.h"
+#include "rocksdb/advanced_compression.h"
 #include "rocksdb/compression_type.h"
 #include "rocksdb/rocksdb_namespace.h"
 #include "util/autovector.h"
@@ -35,7 +36,20 @@ class BlobFileReader {
                        HistogramImpl* blob_file_read_hist,
                        uint64_t blob_file_number,
                        const std::shared_ptr<IOTracer>& io_tracer,
-                       std::unique_ptr<BlobFileReader>* reader);
+                       std::unique_ptr<BlobFileReader>* reader) {
+    return Create(immutable_options, read_options, file_options,
+                  column_family_id, blob_file_read_hist, blob_file_number,
+                  io_tracer, /*skip_footer_validation=*/false, reader);
+  }
+
+  // Allows opening in-flight direct-write blob files by optionally skipping
+  // footer validation.
+  static Status Create(
+      const ImmutableOptions& immutable_options,
+      const ReadOptions& read_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,
+      bool skip_footer_validation, std::unique_ptr<BlobFileReader>* reader);
 
   BlobFileReader(const BlobFileReader&) = delete;
   BlobFileReader& operator=(const BlobFileReader&) = delete;
@@ -62,17 +76,22 @@ class BlobFileReader {
   uint64_t GetFileSize() const { return file_size_; }
 
  private:
+  // `has_footer` tracks whether offset validation should reserve footer space.
   BlobFileReader(std::unique_ptr<RandomAccessFileReader>&& file_reader,
                  uint64_t file_size, CompressionType compression_type,
-                 SystemClock* clock, Statistics* statistics);
+                 std::shared_ptr<Decompressor> decompressor, SystemClock* clock,
+                 Statistics* statistics, bool has_footer);
 
+  // `skip_footer_size_check` is used for direct-write files that are still
+  // missing their footer at open time.
   static Status OpenFile(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);
+                         std::unique_ptr<RandomAccessFileReader>* file_reader,
+                         bool skip_footer_size_check);
 
   static Status ReadHeader(const RandomAccessFileReader* file_reader,
                            const ReadOptions& read_options,
@@ -96,6 +115,7 @@ class BlobFileReader {
 
   static Status UncompressBlobIfNeeded(const Slice& value_slice,
                                        CompressionType compression_type,
+                                       Decompressor* decompressor,
                                        MemoryAllocator* allocator,
                                        SystemClock* clock,
                                        Statistics* statistics,
@@ -104,8 +124,11 @@ class BlobFileReader {
   std::unique_ptr<RandomAccessFileReader> file_reader_;
   uint64_t file_size_;
   CompressionType compression_type_;
+  std::shared_ptr<Decompressor> decompressor_;
   SystemClock* clock_;
   Statistics* statistics_;
+  // False when the reader was opened before the blob file footer was written.
+  bool has_footer_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

db/blob/blob_file_reader_test.cc

@@ -65,7 +65,7 @@ void WriteBlobFile(const ImmutableOptions& immutable_options,
 
   ASSERT_OK(blob_log_writer.WriteHeader(WriteOptions(), header));
 
-  std::vector<std::string> compressed_blobs(num);
+  std::vector<GrowableBuffer> compressed_blobs(num);
   std::vector<Slice> blobs_to_write(num);
   if (kNoCompression == compression) {
     for (size_t i = 0; i < num; ++i) {
@@ -73,17 +73,13 @@ void WriteBlobFile(const ImmutableOptions& immutable_options,
       blob_sizes[i] = blobs[i].size();
     }
   } else {
-    CompressionOptions opts;
-    CompressionContext context(compression, opts);
-    constexpr uint64_t sample_for_compression = 0;
-    CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(),
-                         compression, sample_for_compression);
-
-    constexpr uint32_t compression_format_version = 2;
+    auto compressor =
+        GetBuiltinV2CompressionManager()->GetCompressor({}, compression);
 
     for (size_t i = 0; i < num; ++i) {
-      ASSERT_TRUE(CompressData(blobs[i], info, compression_format_version,
-                               &compressed_blobs[i]));
+      ASSERT_OK(LegacyForceBuiltinCompression(*compressor,
+                                              /*working_area=*/nullptr,
+                                              blobs[i], &compressed_blobs[i]));
       blobs_to_write[i] = compressed_blobs[i];
       blob_sizes[i] = compressed_blobs[i].size();
     }
@@ -810,11 +806,10 @@ TEST_F(BlobFileReaderTest, UncompressionError) {
 
   SyncPoint::GetInstance()->SetCallBack(
       "BlobFileReader::UncompressBlobIfNeeded:TamperWithResult", [](void* arg) {
-        CacheAllocationPtr* const output =
-            static_cast<CacheAllocationPtr*>(arg);
-        assert(output);
+        auto* result = static_cast<Status*>(arg);
+        assert(result);
 
-        output->reset();
+        *result = Status::Corruption("Injected result");
       });
 
   SyncPoint::GetInstance()->EnableProcessing();
@@ -825,11 +820,12 @@ TEST_F(BlobFileReaderTest, UncompressionError) {
   std::unique_ptr<BlobContents> value;
   uint64_t bytes_read = 0;
 
-  ASSERT_TRUE(reader
-                  ->GetBlob(ReadOptions(), key, blob_offset, blob_size,
-                            kSnappyCompression, prefetch_buffer, allocator,
-                            &value, &bytes_read)
-                  .IsCorruption());
+  ASSERT_EQ(reader
+                ->GetBlob(ReadOptions(), key, blob_offset, blob_size,
+                          kSnappyCompression, prefetch_buffer, allocator,
+                          &value, &bytes_read)
+                .code(),
+            Status::Code::kCorruption);
   ASSERT_EQ(value, nullptr);
   ASSERT_EQ(bytes_read, 0);
 
@@ -1015,6 +1011,92 @@ TEST_P(BlobFileReaderDecodingErrorTest, DecodingError) {
   SyncPoint::GetInstance()->ClearAllCallBacks();
 }
 
+TEST_F(BlobFileReaderTest, MultiGetBlobWithFailedValidation) {
+  // Test that MultiGetBlob correctly handles the case where some requests
+  // fail validation. The adjustments vector is only populated for requests
+  // that pass validation, so the indices must track correctly.
+  Options options;
+  options.env = mock_env_.get();
+  options.cf_paths.emplace_back(
+      test::PerThreadDBPath(
+          mock_env_.get(),
+          "BlobFileReaderTest_MultiGetBlobWithFailedValidation"),
+      0);
+  options.enable_blob_files = true;
+
+  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 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"};
+
+  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]};
+
+  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;
+
+  ReadOptions read_options;
+  ASSERT_OK(BlobFileReader::Create(
+      immutable_options, read_options, FileOptions(), column_family_id,
+      blob_file_read_hist, blob_file_number, nullptr /*IOTracer*/, &reader));
+
+  // Enable checksum verification so adjustments are non-zero
+  read_options.verify_checksums = true;
+  constexpr MemoryAllocator* allocator = nullptr;
+
+  // Fail the first request by giving it an invalid offset (too small).
+  // This causes the first request to be skipped in the adjustments vector,
+  // so adjustments has only 2 entries (for blobs 1 and 2), while blob_reqs
+  // has 3 entries. Without the fix, adjustments[i] would use the wrong
+  // index for the remaining valid requests.
+  std::array<Status, num_blobs> statuses_buf;
+  std::array<BlobReadRequest, num_blobs> requests_buf;
+  autovector<std::pair<BlobReadRequest*, std::unique_ptr<BlobContents>>>
+      blob_reqs;
+
+  // First request: invalid offset (too small, will fail validation)
+  requests_buf[0] = BlobReadRequest(keys[0], /*offset=*/0, blob_sizes[0],
+                                    kNoCompression, nullptr, &statuses_buf[0]);
+  // Second and third requests: valid
+  requests_buf[1] = BlobReadRequest(keys[1], blob_offsets[1], blob_sizes[1],
+                                    kNoCompression, nullptr, &statuses_buf[1]);
+  requests_buf[2] = BlobReadRequest(keys[2], blob_offsets[2], blob_sizes[2],
+                                    kNoCompression, nullptr, &statuses_buf[2]);
+
+  for (size_t i = 0; i < num_blobs; ++i) {
+    blob_reqs.emplace_back(&requests_buf[i], std::unique_ptr<BlobContents>());
+  }
+
+  uint64_t bytes_read = 0;
+  reader->MultiGetBlob(read_options, allocator, blob_reqs, &bytes_read);
+
+  // First request should fail validation
+  ASSERT_TRUE(statuses_buf[0].IsCorruption());
+  ASSERT_EQ(blob_reqs[0].second, nullptr);
+
+  // Second and third requests should succeed with correct data
+  ASSERT_OK(statuses_buf[1]);
+  ASSERT_NE(blob_reqs[1].second, nullptr);
+  ASSERT_EQ(blob_reqs[1].second->data(), blobs[1]);
+
+  ASSERT_OK(statuses_buf[2]);
+  ASSERT_NE(blob_reqs[2].second, nullptr);
+  ASSERT_EQ(blob_reqs[2].second->data(), blobs[2]);
+}
+
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {

db/blob/blob_garbage_meter.cc

@@ -8,70 +8,48 @@
 #include "db/blob/blob_index.h"
 #include "db/blob/blob_log_format.h"
 #include "db/dbformat.h"
+#include "db/wide/wide_column_serialization.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();
+  return ProcessFlow(key, value, /*is_inflow=*/true);
 }
 
 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();
+  return ProcessFlow(key, value, /*is_inflow=*/false);
 }
 
-Status BlobGarbageMeter::Parse(const Slice& key, const Slice& value,
-                               uint64_t* blob_file_number, uint64_t* bytes) {
+Status BlobGarbageMeter::GetBlobReferenceDetails(const ParsedInternalKey& ikey,
+                                                 const BlobIndex& blob_index,
+                                                 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 (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();
+}
+
+Status BlobGarbageMeter::ParseBlobIndexReference(const ParsedInternalKey& ikey,
+                                                 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);
+
   if (ikey.type != kTypeBlobIndex) {
     return Status::OK();
   }
@@ -85,16 +63,71 @@ Status BlobGarbageMeter::Parse(const Slice& key, const Slice& value,
     }
   }
 
-  if (blob_index.IsInlined() || blob_index.HasTTL()) {
-    return Status::Corruption("Unexpected TTL/inlined blob index");
+  return GetBlobReferenceDetails(ikey, blob_index, blob_file_number, bytes);
+}
+
+void BlobGarbageMeter::AddFlow(uint64_t blob_file_number, uint64_t bytes,
+                               bool is_inflow) {
+  if (is_inflow) {
+    flows_[blob_file_number].AddInFlow(bytes);
+    return;
   }
 
-  *blob_file_number = blob_index.file_number();
-  *bytes =
-      blob_index.size() +
-      BlobLogRecord::CalculateAdjustmentForRecordHeader(ikey.user_key.size());
+  // 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()) {
+    it->second.AddOutFlow(bytes);
+  }
+}
 
-  return Status::OK();
+Status BlobGarbageMeter::ProcessFlow(const Slice& key, const Slice& value,
+                                     bool is_inflow) {
+  ParsedInternalKey ikey;
+
+  {
+    constexpr bool log_err_key = false;
+    const Status s = ParseInternalKey(key, &ikey, log_err_key);
+    if (!s.ok()) {
+      return s;
+    }
+  }
+
+  uint64_t blob_file_number = kInvalidBlobFileNumber;
+  uint64_t bytes = 0;
+  if (Status s =
+          ParseBlobIndexReference(ikey, value, &blob_file_number, &bytes);
+      !s.ok()) {
+    return s;
+  }
+
+  if (blob_file_number != kInvalidBlobFileNumber) {
+    AddFlow(blob_file_number, bytes, is_inflow);
+    return Status::OK();
+  }
+
+  return ProcessEntityBlobReferences(ikey, value, is_inflow);
+}
+
+Status BlobGarbageMeter::ProcessEntityBlobReferences(
+    const ParsedInternalKey& ikey, const Slice& value, bool is_inflow) {
+  if (ikey.type != kTypeWideColumnEntity) {
+    return Status::OK();
+  }
+
+  return WideColumnSerialization::ForEachBlobFileNumber(
+      value, [&](const BlobIndex& blob_index) -> Status {
+        uint64_t file_number = kInvalidBlobFileNumber;
+        uint64_t blob_bytes = 0;
+        if (const Status s = GetBlobReferenceDetails(ikey, blob_index,
+                                                     &file_number, &blob_bytes);
+            !s.ok()) {
+          return s;
+        }
+        AddFlow(file_number, blob_bytes, is_inflow);
+        return Status::OK();
+      });
 }
 
 }  // namespace ROCKSDB_NAMESPACE

db/blob/blob_garbage_meter.h

@@ -15,6 +15,8 @@
 
 namespace ROCKSDB_NAMESPACE {
 
+class BlobIndex;
+struct ParsedInternalKey;
 class Slice;
 
 // A class that can be used to compute the amount of additional garbage
@@ -93,8 +95,19 @@ class BlobGarbageMeter {
   }
 
  private:
-  static Status Parse(const Slice& key, const Slice& value,
-                      uint64_t* blob_file_number, uint64_t* bytes);
+  static Status GetBlobReferenceDetails(const ParsedInternalKey& ikey,
+                                        const BlobIndex& blob_index,
+                                        uint64_t* blob_file_number,
+                                        uint64_t* bytes);
+  static Status ParseBlobIndexReference(const ParsedInternalKey& ikey,
+                                        const Slice& value,
+                                        uint64_t* blob_file_number,
+                                        uint64_t* bytes);
+
+  void AddFlow(uint64_t blob_file_number, uint64_t bytes, bool is_inflow);
+  Status ProcessFlow(const Slice& key, const Slice& value, bool is_inflow);
+  Status ProcessEntityBlobReferences(const ParsedInternalKey& ikey,
+                                     const Slice& value, bool is_inflow);
 
   std::unordered_map<uint64_t, BlobInOutFlow> flows_;
 };

db/blob/blob_garbage_meter_test.cc

@@ -11,10 +11,23 @@
 #include "db/blob/blob_index.h"
 #include "db/blob/blob_log_format.h"
 #include "db/dbformat.h"
+#include "db/wide/wide_column_serialization.h"
 #include "test_util/testharness.h"
 
 namespace ROCKSDB_NAMESPACE {
 
+namespace {
+
+BlobIndex MakeBlobIndex(uint64_t file_number, uint64_t offset, uint64_t size) {
+  std::string encoded;
+  BlobIndex::EncodeBlob(&encoded, file_number, offset, size, kNoCompression);
+  BlobIndex blob_index;
+  EXPECT_OK(blob_index.DecodeFrom(encoded));
+  return blob_index;
+}
+
+}  // namespace
+
 TEST(BlobGarbageMeterTest, MeasureGarbage) {
   BlobGarbageMeter blob_garbage_meter;
 
@@ -188,6 +201,67 @@ TEST(BlobGarbageMeterTest, InlinedTTLBlobIndex) {
   ASSERT_NOK(blob_garbage_meter.ProcessOutFlow(key_slice, value_slice));
 }
 
+TEST(BlobGarbageMeterTest, WideColumnEntity) {
+  constexpr char user_key[] = "entity_key";
+  constexpr SequenceNumber seq = 123;
+  const InternalKey key(user_key, seq, kTypeWideColumnEntity);
+  const Slice key_slice = key.Encode();
+
+  const std::vector<std::pair<std::string, std::string>> columns = {
+      {"", "default_inline"},
+      {"blob_attr", "blob_inline"},
+      {"ttl", "00000001"},
+  };
+
+  const BlobIndex default_blob = MakeBlobIndex(4, 123, 555);
+  const BlobIndex attr_blob = MakeBlobIndex(5, 456, 777);
+
+  std::string inflow_value;
+  ASSERT_OK(WideColumnSerialization::SerializeV2(
+      columns, {{0, default_blob}, {1, attr_blob}}, inflow_value));
+
+  std::string outflow_value;
+  ASSERT_OK(WideColumnSerialization::SerializeV2(columns, {{0, default_blob}},
+                                                 outflow_value));
+
+  BlobGarbageMeter blob_garbage_meter;
+  ASSERT_OK(blob_garbage_meter.ProcessInFlow(key_slice, inflow_value));
+  ASSERT_OK(blob_garbage_meter.ProcessOutFlow(key_slice, outflow_value));
+
+  const auto& flows = blob_garbage_meter.flows();
+  ASSERT_EQ(flows.size(), 2);
+
+  constexpr size_t kUserKeySize = sizeof(user_key) - 1;
+  const uint64_t default_bytes =
+      default_blob.size() +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(kUserKeySize);
+  const uint64_t attr_bytes =
+      attr_blob.size() +
+      BlobLogRecord::CalculateAdjustmentForRecordHeader(kUserKeySize);
+
+  {
+    const auto it = flows.find(default_blob.file_number());
+    ASSERT_NE(it, flows.end());
+    ASSERT_EQ(it->second.GetInFlow().GetCount(), 1);
+    ASSERT_EQ(it->second.GetInFlow().GetBytes(), default_bytes);
+    ASSERT_EQ(it->second.GetOutFlow().GetCount(), 1);
+    ASSERT_EQ(it->second.GetOutFlow().GetBytes(), default_bytes);
+    ASSERT_FALSE(it->second.HasGarbage());
+  }
+
+  {
+    const auto it = flows.find(attr_blob.file_number());
+    ASSERT_NE(it, flows.end());
+    ASSERT_EQ(it->second.GetInFlow().GetCount(), 1);
+    ASSERT_EQ(it->second.GetInFlow().GetBytes(), attr_bytes);
+    ASSERT_EQ(it->second.GetOutFlow().GetCount(), 0);
+    ASSERT_EQ(it->second.GetOutFlow().GetBytes(), 0);
+    ASSERT_TRUE(it->second.HasGarbage());
+    ASSERT_EQ(it->second.GetGarbageCount(), 1);
+    ASSERT_EQ(it->second.GetGarbageBytes(), attr_bytes);
+  }
+}
+
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {

db/blob/blob_index.h

@@ -137,6 +137,18 @@ class BlobIndex {
     return oss.str();
   }
 
+  // Encode this blob index into dst based on its type.
+  void EncodeTo(std::string* dst) const {
+    if (IsInlined()) {
+      EncodeInlinedTTL(dst, expiration_, value_);
+    } else if (HasTTL()) {
+      EncodeBlobTTL(dst, expiration_, file_number_, offset_, size_,
+                    compression_);
+    } else {
+      EncodeBlob(dst, file_number_, offset_, size_, compression_);
+    }
+  }
+
   static void EncodeInlinedTTL(std::string* dst, uint64_t expiration,
                                const Slice& value) {
     assert(dst != nullptr);

db/blob/blob_log_format.h

@@ -148,13 +148,26 @@ struct BlobLogRecord {
 
 // Checks whether a blob offset is potentially valid or not.
 inline bool IsValidBlobOffset(uint64_t value_offset, uint64_t key_size,
-                              uint64_t value_size, uint64_t file_size) {
-  if (value_offset <
-      BlobLogHeader::kSize + BlobLogRecord::kHeaderSize + key_size) {
+                              uint64_t value_size, uint64_t file_size,
+                              bool has_footer = true) {
+  constexpr uint64_t kMinPrefix =
+      BlobLogHeader::kSize + BlobLogRecord::kHeaderSize;
+  if (value_offset < kMinPrefix) {
+    return false;
+  }
+  if (value_offset - kMinPrefix < key_size) {
     return false;
   }
 
-  if (value_offset + value_size + BlobLogFooter::kSize > file_size) {
+  const uint64_t footer_size = has_footer ? BlobLogFooter::kSize : 0;
+  if (file_size < footer_size) {
+    return false;
+  }
+  const uint64_t max_value_end = file_size - footer_size;
+  if (value_size > max_value_end) {
+    return false;
+  }
+  if (value_offset > max_value_end - value_size) {
     return false;
   }
 

db/blob/blob_source.cc

@@ -20,6 +20,21 @@
 
 namespace ROCKSDB_NAMESPACE {
 
+namespace {
+
+Status AppendBlobRefreshRetryFailure(const Status& stale_status,
+                                     const Status& retry_status) {
+  assert(stale_status.IsCorruption());
+  assert(!retry_status.ok());
+  if (retry_status.IsCorruption()) {
+    return retry_status;
+  }
+  return Status::CopyAppendMessage(
+      stale_status, "; refresh retry failed: ", retry_status.ToString());
+}
+
+}  // namespace
+
 BlobSource::BlobSource(const ImmutableOptions& immutable_options,
                        const MutableCFOptions& mutable_cf_options,
                        const std::string& db_id,
@@ -231,6 +246,38 @@ Status BlobSource::GetBlob(const ReadOptions& read_options,
     s = blob_file_reader.GetValue()->GetBlob(
         read_options, user_key, offset, value_size, compression_type,
         prefetch_buffer, allocator, &blob_contents, &read_size);
+    if (s.IsCorruption()) {
+      const Status stale_status = s;
+      blob_file_reader.Reset();
+      blob_file_cache_->Evict(file_number);
+
+      std::unique_ptr<BlobFileReader> fresh_reader;
+      s = blob_file_cache_->OpenBlobFileReaderUncached(
+          read_options, file_number, &fresh_reader,
+          /*allow_footer_skip_retry=*/false);
+      if (!s.ok()) {
+        return AppendBlobRefreshRetryFailure(stale_status, s);
+      }
+
+      if (compression_type != fresh_reader->GetCompressionType()) {
+        return Status::Corruption(
+            "Compression type mismatch when reading blob");
+      }
+
+      blob_contents.reset();
+      read_size = 0;
+      s = fresh_reader->GetBlob(read_options, user_key, offset, value_size,
+                                compression_type, prefetch_buffer, allocator,
+                                &blob_contents, &read_size);
+      if (!s.ok()) {
+        s = AppendBlobRefreshRetryFailure(stale_status, s);
+      } else {
+        CacheHandleGuard<BlobFileReader> ignored_reader;
+        blob_file_cache_
+            ->RefreshBlobFileReader(file_number, &fresh_reader, &ignored_reader)
+            .PermitUncheckedError();
+      }
+    }
     if (!s.ok()) {
       return s;
     }
@@ -397,6 +444,89 @@ void BlobSource::MultiGetBlobFromOneFile(const ReadOptions& read_options,
     blob_file_reader.GetValue()->MultiGetBlob(read_options, allocator,
                                               _blob_reqs, &_bytes_read);
 
+    bool needs_reader_refresh = false;
+    for (const auto& blob_req : _blob_reqs) {
+      BlobReadRequest* const req = blob_req.first;
+      assert(req != nullptr);
+      assert(req->status != nullptr);
+      if (req->status->IsCorruption()) {
+        needs_reader_refresh = true;
+        break;
+      }
+    }
+
+    if (needs_reader_refresh) {
+      blob_file_reader.Reset();
+      blob_file_cache_->Evict(file_number);
+
+      std::unique_ptr<BlobFileReader> fresh_reader;
+      s = blob_file_cache_->OpenBlobFileReaderUncached(
+          read_options, file_number, &fresh_reader,
+          /*allow_footer_skip_retry=*/false);
+      if (!s.ok()) {
+        for (const auto& blob_req : _blob_reqs) {
+          BlobReadRequest* const req = blob_req.first;
+          assert(req != nullptr);
+          assert(req->status != nullptr);
+          if (req->status->IsCorruption()) {
+            *req->status = AppendBlobRefreshRetryFailure(*req->status, s);
+          }
+        }
+        return;
+      }
+
+      autovector<std::pair<BlobReadRequest*, std::unique_ptr<BlobContents>>>
+          retry_blob_reqs;
+      autovector<Status> stale_statuses;
+      for (auto& blob_req : _blob_reqs) {
+        BlobReadRequest* const req = blob_req.first;
+        assert(req != nullptr);
+        assert(req->status != nullptr);
+        if (!req->status->IsCorruption()) {
+          continue;
+        }
+
+        stale_statuses.emplace_back(*req->status);
+        *req->status = Status::OK();
+        blob_req.second.reset();
+        retry_blob_reqs.emplace_back(req, std::unique_ptr<BlobContents>());
+      }
+
+      uint64_t refreshed_bytes_read = 0;
+      fresh_reader->MultiGetBlob(read_options, allocator, retry_blob_reqs,
+                                 &refreshed_bytes_read);
+      _bytes_read += refreshed_bytes_read;
+
+      bool install_fresh_reader = false;
+      for (size_t i = 0; i < retry_blob_reqs.size(); ++i) {
+        auto& retried_blob_req = retry_blob_reqs[i];
+        BlobReadRequest* const retried_req = retried_blob_req.first;
+        assert(retried_req != nullptr);
+        if (retried_req->status->ok()) {
+          install_fresh_reader = true;
+        } else {
+          *retried_req->status = AppendBlobRefreshRetryFailure(
+              stale_statuses[i], *retried_req->status);
+        }
+
+        for (auto& blob_req : _blob_reqs) {
+          if (blob_req.first != retried_req) {
+            continue;
+          }
+
+          blob_req.second = std::move(retried_blob_req.second);
+          break;
+        }
+      }
+
+      if (install_fresh_reader) {
+        CacheHandleGuard<BlobFileReader> ignored_reader;
+        blob_file_cache_
+            ->RefreshBlobFileReader(file_number, &fresh_reader, &ignored_reader)
+            .PermitUncheckedError();
+      }
+    }
+
     if (blob_cache_ && read_options.fill_cache) {
       // If filling cache is allowed and a cache is configured, try to put
       // the blob(s) to the cache.