Bumping version to 5.8

Summary: Closes https://github.com/facebook/rocksdb/pull/2738 Differential Revision: D5736261 Pulled By: maysamyabandeh fbshipit-source-id: 49d27e9ccd786c4056a3d586a060fe460ea883ac
update HISTORY.md for DeleteRange bug fix
2026-11-06 19:12:36 -05:00 · 2017-08-30 14:26:12 -07:00 · 2017-08-29 22:26:47 -07:00 · 2017-08-29 21:56:02 -07:00 · 2017-08-29 18:41:35 -07:00 · 2017-08-29 12:11:56 -07:00
276 changed files with 7670 additions and 8930 deletions
@@ -1,17 +0,0 @@
-{
-  "project_id" : "rocksdb",
-  "conduit_uri" : "https://phabricator.fb.com/api/",
-  "copyright_holder" : "Facebook",
-  "load" : [
-    "arcanist_util"
-  ],
-  "lint.engine" : "FacebookFbcodeLintEngine",
-  "lint.engine.single.linter" : "FbcodeCppLinter",
-  "unit.engine" : "FacebookFbcodeUnitTestEngine",
-  "arcanist_configuration" : "FacebookArcanistConfiguration",
-  "base" : "git:HEAD^, hg:.^",
-  "git.default-relative-commit" : "HEAD^",
-  "git:arc.feature.start.default" : "origin/master",
-  "arc.feature.start.default" : "master",
-  "history.immutable" : false
-}
@@ -39,7 +39,6 @@ coverage/COVERAGE_REPORT
 .gdbhistory
 .gdb_history
 package/
-.phutil_module_cache
 unity.a
 tags
 etags
@@ -57,7 +57,7 @@ before_script:

 script:
  - ${CXX} --version
-  - if [ "${TEST_GROUP}" == 'platform_dependent' ]; then OPT=-DTRAVIS V=1 make -j4 all; OPT=-DTRAVIS V=1 ROCKSDBTESTS_END=db_block_cache_test make -j4 check_some; fi
+  - if [ "${TEST_GROUP}" == 'platform_dependent' ]; then ccache -C && OPT=-DTRAVIS V=1 ROCKSDBTESTS_END=db_block_cache_test make -j4 all_but_some_tests check_some; fi
  - if [ "${TEST_GROUP}" == '1' ]; then OPT=-DTRAVIS V=1 ROCKSDBTESTS_START=db_block_cache_test ROCKSDBTESTS_END=comparator_db_test make -j4 check_some; fi
  - if [ "${TEST_GROUP}" == '2' ]; then OPT=-DTRAVIS V=1 ROCKSDBTESTS_START=comparator_db_test make -j4 check_some; fi
  - if [ "${JOB_NAME}" == 'java_test' ]; then OPT=-DTRAVIS V=1 make clean jclean && make rocksdbjava jtest; fi
@@ -56,6 +56,7 @@ else()
      include_directories(${JEMALLOC_INCLUDE_DIR})
    endif()
  endif()
+
  option(WITH_SNAPPY "build with SNAPPY" OFF)
  if(WITH_SNAPPY)
    find_package(snappy REQUIRED)
@@ -63,6 +64,38 @@ else()
    include_directories(${SNAPPY_INCLUDE_DIR})
    list(APPEND THIRDPARTY_LIBS ${SNAPPY_LIBRARIES})
  endif()
+
+  option(WITH_ZLIB "build with zlib" OFF)
+  if(WITH_ZLIB)
+    find_package(zlib REQUIRED)
+    add_definitions(-DZLIB)
+    include_directories(${ZLIB_INCLUDE_DIR})
+    list(APPEND THIRDPARTY_LIBS ${ZLIB_LIBRARIES})
+  endif()
+
+  option(WITH_BZ2 "build with bzip2" OFF)
+  if(WITH_BZ2)
+    find_package(bzip2 REQUIRED)
+    add_definitions(-DBZIP2)
+    include_directories(${BZIP2_INCLUDE_DIR})
+    list(APPEND THIRDPARTY_LIBS ${BZIP2_LIBRARIES})
+  endif()
+
+  option(WITH_LZ4 "build with lz4" OFF)
+  if(WITH_LZ4)
+    find_package(lz4 REQUIRED)
+    add_definitions(-DLZ4)
+    include_directories(${LZ4_INCLUDE_DIR})
+    list(APPEND THIRDPARTY_LIBS ${LZ4_LIBRARIES})
+  endif()
+
+  option(WITH_ZSTD "build with zstd" OFF)
+  if(WITH_ZSTD)
+    find_package(zstd REQUIRED)
+    add_definitions(-DZSTD)
+    include_directories(${ZSTD_INCLUDE_DIR})
+    list(APPEND THIRDPARTY_LIBS ${ZSTD_LIBRARIES})
+  endif()
 endif()

 if(WIN32)
@@ -115,6 +148,31 @@ if(WIN32 AND MSVC)
  endif()
 endif()

+set(BUILD_VERSION_CC ${CMAKE_BINARY_DIR}/build_version.cc)
+configure_file(util/build_version.cc.in ${BUILD_VERSION_CC} @ONLY)
+add_library(build_version OBJECT ${BUILD_VERSION_CC})
+target_include_directories(build_version PRIVATE
+  ${CMAKE_CURRENT_SOURCE_DIR}/util)
+if(MSVC)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zi /nologo /EHsc /GS /Gd /GR /GF /fp:precise /Zc:wchar_t /Zc:forScope /errorReport:queue")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /FC /d2Zi+ /W3 /wd4127 /wd4800 /wd4996 /wd4351")
+else()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -W -Wextra -Wall")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers")
+  if(MINGW)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-format")
+  endif()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+  if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2 -fno-omit-frame-pointer")
+    include(CheckCXXCompilerFlag)
+    CHECK_CXX_COMPILER_FLAG("-momit-leaf-frame-pointer" HAVE_OMIT_LEAF_FRAME_POINTER)
+    if(HAVE_OMIT_LEAF_FRAME_POINTER)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -momit-leaf-frame-pointer")
+    endif()
+  endif()
+endif()
+
 option(PORTABLE "build a portable binary" OFF)
 option(FORCE_SSE42 "force building with SSE4.2, even when PORTABLE=ON" OFF)
 if(PORTABLE)
@@ -158,32 +216,6 @@ if(HAVE_THREAD_LOCAL)
  add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)
 endif()

-set(BUILD_VERSION_CC ${CMAKE_BINARY_DIR}/build_version.cc)
-configure_file(util/build_version.cc.in ${BUILD_VERSION_CC} @ONLY)
-add_library(build_version OBJECT ${BUILD_VERSION_CC})
-target_include_directories(build_version PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/util)
-if(MSVC)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zi /nologo /EHsc /GS /Gd /GR /GF /fp:precise /Zc:wchar_t /Zc:forScope /errorReport:queue")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /FC /d2Zi+ /W3 /wd4127 /wd4800 /wd4996 /wd4351")
-else()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -W -Wextra -Wall")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers")
-  if(MINGW)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-format")
-  endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-  if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
-    add_definitions(-DNDEBUG)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2 -fno-omit-frame-pointer")
-    include(CheckCXXCompilerFlag)
-    CHECK_CXX_COMPILER_FLAG("-momit-leaf-frame-pointer" HAVE_OMIT_LEAF_FRAME_POINTER)
-    if(HAVE_OMIT_LEAF_FRAME_POINTER)
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -momit-leaf-frame-pointer")
-    endif()
-  endif()
-endif()
-
 option(FAIL_ON_WARNINGS "Treat compile warnings as errors" ON)
 if(FAIL_ON_WARNINGS)
  if(MSVC)
@@ -293,6 +325,7 @@ endif()
 option(WITH_FALLOCATE "build with fallocate" ON)

 if(WITH_FALLOCATE)
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_C_FLAGS})
  include(CheckCSourceCompiles)
  CHECK_C_SOURCE_COMPILES("
 #include <fcntl.h>
@@ -483,6 +516,9 @@ set(SOURCES
        utilities/blob_db/blob_log_writer.cc
        utilities/blob_db/blob_log_format.cc
        utilities/blob_db/ttl_extractor.cc
+        utilities/cassandra/cassandra_compaction_filter.cc
+        utilities/cassandra/format.cc
+        utilities/cassandra/merge_operator.cc
        utilities/checkpoint/checkpoint_impl.cc
        utilities/col_buf_decoder.cc
        utilities/col_buf_encoder.cc
@@ -501,8 +537,6 @@ set(SOURCES
        utilities/memory/memory_util.cc
        utilities/merge_operators/max.cc
        utilities/merge_operators/put.cc
-        utilities/merge_operators/cassandra/format.cc
-        utilities/merge_operators/cassandra/merge_operator.cc
        utilities/merge_operators/string_append/stringappend.cc
        utilities/merge_operators/string_append/stringappend2.cc
        utilities/merge_operators/uint64add.cc
@@ -518,13 +552,14 @@ set(SOURCES
        utilities/spatialdb/spatial_db.cc
        utilities/table_properties_collectors/compact_on_deletion_collector.cc
        utilities/transactions/optimistic_transaction_db_impl.cc
-        utilities/transactions/optimistic_transaction_impl.cc
+        utilities/transactions/optimistic_transaction.cc
        utilities/transactions/transaction_base.cc
-        utilities/transactions/transaction_db_impl.cc
+        utilities/transactions/pessimistic_transaction_db.cc
        utilities/transactions/transaction_db_mutex_impl.cc
-        utilities/transactions/transaction_impl.cc
+        utilities/transactions/pessimistic_transaction.cc
        utilities/transactions/transaction_lock_mgr.cc
        utilities/transactions/transaction_util.cc
+        utilities/transactions/write_prepared_txn.cc
        utilities/ttl/db_ttl_impl.cc
        utilities/write_batch_with_index/write_batch_with_index.cc
        utilities/write_batch_with_index/write_batch_with_index_internal.cc
@@ -600,7 +635,72 @@ else()
  message(STATUS "JNI library is disabled")
 endif()

-set(TESTS
+# Installation and packaging
+if(WIN32)
+  option(ROCKSDB_INSTALL_ON_WINDOWS "Enable install target on Windows" OFF)
+endif()
+if(NOT WIN32 OR ROCKSDB_INSTALL_ON_WINDOWS)
+  if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+    if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+      # Change default installation prefix on Linux to /usr
+      set(CMAKE_INSTALL_PREFIX /usr CACHE PATH "Install path prefix, prepended onto install directories." FORCE)
+    endif()
+  endif()
+
+  include(GNUInstallDirs)
+  include(CMakePackageConfigHelpers)
+
+  set(package_config_destination ${CMAKE_INSTALL_LIBDIR}/cmake/rocksdb)
+
+  configure_package_config_file(
+    ${CMAKE_SOURCE_DIR}/cmake/RocksDBConfig.cmake.in RocksDBConfig.cmake
+    INSTALL_DESTINATION ${package_config_destination}
+  )
+
+  write_basic_package_version_file(
+    RocksDBConfigVersion.cmake
+    VERSION ${ROCKSDB_VERSION}
+    COMPATIBILITY SameMajorVersion
+  )
+
+  install(DIRECTORY include/rocksdb COMPONENT devel DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+
+  install(
+    TARGETS ${ROCKSDB_STATIC_LIB}
+    EXPORT RocksDBTargets
+    COMPONENT devel
+    ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+    INCLUDES DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
+  )
+
+  install(
+    TARGETS ${ROCKSDB_SHARED_LIB}
+    EXPORT RocksDBTargets
+    COMPONENT runtime
+    RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
+    LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+    INCLUDES DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
+  )
+
+  install(
+    EXPORT RocksDBTargets
+    COMPONENT devel
+    DESTINATION ${package_config_destination}
+    NAMESPACE RocksDB::
+  )
+
+  install(
+    FILES
+    ${CMAKE_CURRENT_BINARY_DIR}/RocksDBConfig.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/RocksDBConfigVersion.cmake
+    COMPONENT devel
+    DESTINATION ${package_config_destination}
+  )
+endif()
+
+option(WITH_TESTS "build with tests" ON)
+if(WITH_TESTS)
+  set(TESTS
        cache/cache_test.cc
        cache/lru_cache_test.cc
        db/column_family_test.cc
@@ -706,6 +806,10 @@ set(TESTS
        util/thread_local_test.cc
        utilities/backupable/backupable_db_test.cc
        utilities/blob_db/blob_db_test.cc
+        utilities/cassandra/cassandra_functional_test.cc
+        utilities/cassandra/cassandra_format_test.cc
+        utilities/cassandra/cassandra_row_merge_test.cc
+        utilities/cassandra/cassandra_serialize_test.cc
        utilities/checkpoint/checkpoint_test.cc
        utilities/column_aware_encoding_test.cc
        utilities/date_tiered/date_tiered_test.cc
@@ -714,10 +818,6 @@ set(TESTS
        utilities/geodb/geodb_test.cc
        utilities/lua/rocks_lua_test.cc
        utilities/memory/memory_test.cc
-        utilities/merge_operators/cassandra/cassandra_merge_test.cc
-        utilities/merge_operators/cassandra/cassandra_format_test.cc
-        utilities/merge_operators/cassandra/cassandra_row_merge_test.cc
-        utilities/merge_operators/cassandra/cassandra_serialize_test.cc
        utilities/merge_operators/string_append/stringappend_test.cc
        utilities/object_registry_test.cc
        utilities/option_change_migration/option_change_migration_test.cc
@@ -726,98 +826,94 @@ set(TESTS
        utilities/persistent_cache/persistent_cache_test.cc
        utilities/redis/redis_lists_test.cc
        utilities/spatialdb/spatial_db_test.cc
+        utilities/simulator_cache/sim_cache_test.cc
        utilities/table_properties_collectors/compact_on_deletion_collector_test.cc
        utilities/transactions/optimistic_transaction_test.cc
        utilities/transactions/transaction_test.cc
        utilities/ttl/ttl_test.cc
        utilities/write_batch_with_index/write_batch_with_index_test.cc
-)
-if(WITH_LIBRADOS)
-  list(APPEND TESTS utilities/env_librados_test.cc)
-endif()
+  )
+  if(WITH_LIBRADOS)
+    list(APPEND TESTS utilities/env_librados_test.cc)
+  endif()

-set(BENCHMARKS
-  cache/cache_bench.cc
-  memtable/memtablerep_bench.cc
-  tools/db_bench.cc
-  table/table_reader_bench.cc
-  utilities/column_aware_encoding_exp.cc
-  utilities/persistent_cache/hash_table_bench.cc)
-add_library(testharness OBJECT util/testharness.cc)
-foreach(sourcefile ${BENCHMARKS})
-  get_filename_component(exename ${sourcefile} NAME_WE)
-  add_executable(${exename}${ARTIFACT_SUFFIX} ${sourcefile}
-    $<TARGET_OBJECTS:testharness>)
-  target_link_libraries(${exename}${ARTIFACT_SUFFIX} gtest ${LIBS})
-endforeach(sourcefile ${BENCHMARKS})
-
-# For test util library that is build only in DEBUG mode
-# and linked to tests. Add test only code that is not #ifdefed for Release here.
-set(TESTUTIL_SOURCE
-    db/db_test_util.cc
-    monitoring/thread_status_updater_debug.cc
-    table/mock_table.cc
-    util/fault_injection_test_env.cc
-    utilities/merge_operators/cassandra/test_utils.cc
-)
-# test utilities are only build in debug
-enable_testing()
-add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND})
-set(TESTUTILLIB testutillib${ARTIFACT_SUFFIX})
-add_library(${TESTUTILLIB} STATIC ${TESTUTIL_SOURCE})
-if(MSVC)
-  set_target_properties(${TESTUTILLIB} PROPERTIES COMPILE_FLAGS "/Fd${CMAKE_CFG_INTDIR}/testutillib${ARTIFACT_SUFFIX}.pdb")
-endif()
-set_target_properties(${TESTUTILLIB}
-      PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
-      EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
-      EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
-      )
-
-# Tests are excluded from Release builds
-set(TEST_EXES ${TESTS})
-
-foreach(sourcefile ${TEST_EXES})
+  set(BENCHMARKS
+    cache/cache_bench.cc
+    memtable/memtablerep_bench.cc
+    tools/db_bench.cc
+    table/table_reader_bench.cc
+    utilities/column_aware_encoding_exp.cc
+    utilities/persistent_cache/hash_table_bench.cc)
+  add_library(testharness OBJECT util/testharness.cc)
+  foreach(sourcefile ${BENCHMARKS})
    get_filename_component(exename ${sourcefile} NAME_WE)
    add_executable(${exename}${ARTIFACT_SUFFIX} ${sourcefile}
      $<TARGET_OBJECTS:testharness>)
-    set_target_properties(${exename}${ARTIFACT_SUFFIX}
-      PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
-      EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
-      EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
-      )
-    target_link_libraries(${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} gtest ${LIBS})
-    if(NOT "${exename}" MATCHES "db_sanity_test")
+    target_link_libraries(${exename}${ARTIFACT_SUFFIX} gtest ${LIBS})
+  endforeach(sourcefile ${BENCHMARKS})
+
+  # For test util library that is build only in DEBUG mode
+  # and linked to tests. Add test only code that is not #ifdefed for Release here.
+  set(TESTUTIL_SOURCE
+      db/db_test_util.cc
+      monitoring/thread_status_updater_debug.cc
+      table/mock_table.cc
+      util/fault_injection_test_env.cc
+      utilities/cassandra/test_utils.cc
+  )
+  # test utilities are only build in debug
+  enable_testing()
+  add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND})
+  set(TESTUTILLIB testutillib${ARTIFACT_SUFFIX})
+  add_library(${TESTUTILLIB} STATIC ${TESTUTIL_SOURCE})
+  if(MSVC)
+    set_target_properties(${TESTUTILLIB} PROPERTIES COMPILE_FLAGS "/Fd${CMAKE_CFG_INTDIR}/testutillib${ARTIFACT_SUFFIX}.pdb")
+  endif()
+  set_target_properties(${TESTUTILLIB}
+        PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
+        EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
+        EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
+        )
+
+  # Tests are excluded from Release builds
+  set(TEST_EXES ${TESTS})
+
+  foreach(sourcefile ${TEST_EXES})
+      get_filename_component(exename ${sourcefile} NAME_WE)
+      add_executable(${exename}${ARTIFACT_SUFFIX} ${sourcefile}
+        $<TARGET_OBJECTS:testharness>)
+      set_target_properties(${exename}${ARTIFACT_SUFFIX}
+        PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
+        EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
+        EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
+        )
+      target_link_libraries(${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} gtest ${LIBS})
+      if(NOT "${exename}" MATCHES "db_sanity_test")
+        add_test(NAME ${exename} COMMAND ${exename}${ARTIFACT_SUFFIX})
+        add_dependencies(check ${exename}${ARTIFACT_SUFFIX})
+      endif()
+  endforeach(sourcefile ${TEST_EXES})
+
+  # C executables must link to a shared object
+  set(C_TESTS db/c_test.c)
+  set(C_TEST_EXES ${C_TESTS})
+
+  foreach(sourcefile ${C_TEST_EXES})
+      string(REPLACE ".c" "" exename ${sourcefile})
+      string(REGEX REPLACE "^((.+)/)+" "" exename ${exename})
+      add_executable(${exename}${ARTIFACT_SUFFIX} ${sourcefile})
+      set_target_properties(${exename}${ARTIFACT_SUFFIX}
+        PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
+        EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
+        EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
+        )
+      target_link_libraries(${exename}${ARTIFACT_SUFFIX} ${ROCKSDB_IMPORT_LIB} testutillib${ARTIFACT_SUFFIX})
      add_test(NAME ${exename} COMMAND ${exename}${ARTIFACT_SUFFIX})
      add_dependencies(check ${exename}${ARTIFACT_SUFFIX})
-    endif()
-endforeach(sourcefile ${TEST_EXES})
-
-# C executables must link to a shared object
-set(C_TESTS db/c_test.c)
-set(C_TEST_EXES ${C_TESTS})
-
-foreach(sourcefile ${C_TEST_EXES})
-    string(REPLACE ".c" "" exename ${sourcefile})
-    string(REGEX REPLACE "^((.+)/)+" "" exename ${exename})
-    add_executable(${exename}${ARTIFACT_SUFFIX} ${sourcefile})
-    set_target_properties(${exename}${ARTIFACT_SUFFIX}
-      PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
-      EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
-      EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
-      )
-    target_link_libraries(${exename}${ARTIFACT_SUFFIX} ${ROCKSDB_IMPORT_LIB} testutillib${ARTIFACT_SUFFIX})
-    add_test(NAME ${exename} COMMAND ${exename}${ARTIFACT_SUFFIX})
-    add_dependencies(check ${exename}${ARTIFACT_SUFFIX})
-endforeach(sourcefile ${C_TEST_EXES})
-add_subdirectory(tools)
-
-# Installation and packaging for Linux
-if(NOT WIN32)
-install(TARGETS ${ROCKSDB_STATIC_LIB} COMPONENT devel ARCHIVE DESTINATION lib64)
-install(TARGETS ${ROCKSDB_SHARED_LIB} COMPONENT runtime DESTINATION lib64)
-install(DIRECTORY "${PROJECT_SOURCE_DIR}/include/rocksdb/"
-        COMPONENT devel
-        DESTINATION include/rocksdb)
-set(CMAKE_INSTALL_PREFIX /usr)
+  endforeach(sourcefile ${C_TEST_EXES})
+endif()
+
+option(WITH_TOOLS "build with tools" ON)
+if(WITH_TOOLS)
+  add_subdirectory(tools)
 endif()
@@ -1,25 +1,29 @@
 # Rocksdb Change Log
-## 5.7.5 (11/28/2017)
+## Unreleased
+### Public API Change
+### New Features
 ### Bug Fixes
-* Fix IOError on WAL write doesn't propagate to write group follower

-## 5.7.4 (08/31/2017)
-No significant changes.
+## 5.8.0 (08/30/2017)
+### Public API Change
+* Users of `Statistics::getHistogramString()` will see fewer histogram buckets and different bucket endpoints.
+* `Slice::compare` and BytewiseComparator `Compare` no longer accept `Slice`s containing nullptr.
+* `Transaction::Get` and `Transaction::GetForUpdate` variants with `PinnableSlice` added.
+
+### New Features
+* Add Iterator::Refresh(), which allows users to update the iterator state so that they can avoid some initialization costs of recreating iterators.
+* Replace dynamic_cast<> (except unit test) so people can choose to build with RTTI off. With make, release mode is by default built with -fno-rtti and debug mode is built without it. Users can override it by setting USE_RTTI=0 or 1.
+* Universal compactions including the bottom level can be executed in a dedicated thread pool. This alleviates head-of-line blocking in the compaction queue, which cause write stalling, particularly in multi-instance use cases. Users can enable this feature via `Env::SetBackgroundThreads(N, Env::Priority::BOTTOM)`, where `N > 0`.
+* Allow merge operator to be called even with a single merge operand during compactions, by appropriately overriding `MergeOperator::AllowSingleOperand`.
+* Add `DB::VerifyChecksum()`, which verifies the checksums in all SST files in a running DB.
+* Block-based table support for disabling checksums by setting `BlockBasedTableOptions::checksum = kNoChecksum`.

-## 5.7.3 (08/29/2017)
 ### Bug Fixes
+* Fix wrong latencies in `rocksdb.db.get.micros`, `rocksdb.db.write.micros`, and `rocksdb.sst.read.micros`.
+* Fix incorrect dropping of deletions during intra-L0 compaction.
 * Fix transient reappearance of keys covered by range deletions when memtable prefix bloom filter is enabled.
 * Fix potentially wrong file smallest key when range deletions separated by snapshot are written together.

-## 5.7.2 (08/15/2017)
-### Bug Fixes
-* Fix incorrect dropping of deletions issue with FIFO compaction.
-* Fix LITE build compiler error with missing abort().
-
-## 5.7.1 (08/13/2017)
-### Bug Fixes
-* Fix incorrect dropping of deletions during intra-L0 compaction.
-
 ## 5.7.0 (07/13/2017)
 ### Public API Change
 * DB property "rocksdb.sstables" now prints keys in hex form.
@@ -113,6 +113,8 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
 * **Windows**:
  * For building with MS Visual Studio 13 you will need Update 4 installed.
  * Read and follow the instructions at CMakeLists.txt
+  * Or install via [vcpkg](https://github.com/microsoft/vcpkg) 
+       * run `vcpkg install rocksdb`

 * **AIX 6.1**
    * Install AIX Toolbox rpms with gcc
@@ -9,5 +9,8 @@ This is the list of all known third-party language bindings for RocksDB. If some
 * Haskell - https://hackage.haskell.org/package/rocksdb-haskell
 * PHP - https://github.com/Photonios/rocksdb-php
 * C# - https://github.com/warrenfalk/rocksdb-sharp
-* Rust - https://github.com/spacejam/rust-rocksdb
+* Rust
+    * https://github.com/spacejam/rust-rocksdb
+    * https://github.com/bh1xuw/rust-rocks
 * D programming language - https://github.com/b1naryth1ef/rocksdb
+* Erlang - https://gitlab.com/barrel-db/erlang-rocksdb
@@ -101,7 +101,19 @@ endif
 ifeq ($(DEBUG_LEVEL),0)
 OPT += -DNDEBUG
 DISABLE_WARNING_AS_ERROR=1
+
+ifneq ($(USE_RTTI), 1)
+	CXXFLAGS += -fno-rtti
 else
+	CXXFLAGS += -DROCKSDB_USE_RTTI
+endif
+else
+ifneq ($(USE_RTTI), 0)
+	CXXFLAGS += -DROCKSDB_USE_RTTI
+else
+	CXXFLAGS += -fno-rtti
+endif
+
 $(warning Warning: Compiling in debug mode. Don't use the resulting binary in production)
 endif

@@ -220,6 +232,10 @@ ifndef DISABLE_JEMALLOC
 		PLATFORM_CXXFLAGS += -DROCKSDB_JEMALLOC -DJEMALLOC_NO_DEMANGLE
 		PLATFORM_CCFLAGS  += -DROCKSDB_JEMALLOC -DJEMALLOC_NO_DEMANGLE
 	endif
+	ifdef WITH_JEMALLOC_FLAG
+		PLATFORM_LDFLAGS += -ljemalloc
+		JAVA_LDFLAGS += -ljemalloc
+	endif
 	EXEC_LDFLAGS := $(JEMALLOC_LIB) $(EXEC_LDFLAGS)
 	PLATFORM_CXXFLAGS += $(JEMALLOC_INCLUDE)
 	PLATFORM_CCFLAGS += $(JEMALLOC_INCLUDE)
@@ -405,7 +421,7 @@ TESTS = \
 	write_buffer_manager_test \
 	stringappend_test \
 	cassandra_format_test \
-	cassandra_merge_test \
+	cassandra_functional_test \
 	cassandra_row_merge_test \
 	cassandra_serialize_test \
 	ttl_test \
@@ -575,6 +591,8 @@ endif  # PLATFORM_SHARED_EXT

 all: $(LIBRARY) $(BENCHMARKS) tools tools_lib test_libs $(TESTS)

+all_but_some_tests: $(LIBRARY) $(BENCHMARKS) tools tools_lib test_libs $(SUBSET)
+
 static_lib: $(LIBRARY)

 shared_lib: $(SHARED)
@@ -778,8 +796,8 @@ ldb_tests: ldb
 crash_test: whitebox_crash_test blackbox_crash_test

 blackbox_crash_test: db_stress
-	python -u tools/db_crashtest.py --simple blackbox
-	python -u tools/db_crashtest.py blackbox
+	python -u tools/db_crashtest.py --simple blackbox $(CRASH_TEST_EXT_ARGS)
+	python -u tools/db_crashtest.py blackbox $(CRASH_TEST_EXT_ARGS)

 ifeq ($(CRASH_TEST_KILL_ODD),)
  CRASH_TEST_KILL_ODD=888887
@@ -787,9 +805,9 @@ endif

 whitebox_crash_test: db_stress
 	python -u tools/db_crashtest.py --simple whitebox --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD)
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
 	python -u tools/db_crashtest.py whitebox  --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD)
+      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)

 asan_check:
 	$(MAKE) clean
@@ -1000,16 +1018,16 @@ option_change_migration_test: utilities/option_change_migration/option_change_mi
 stringappend_test: utilities/merge_operators/string_append/stringappend_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

-cassandra_format_test: utilities/merge_operators/cassandra/cassandra_format_test.o $(LIBOBJECTS) $(TESTHARNESS)
+cassandra_format_test: utilities/cassandra/cassandra_format_test.o utilities/cassandra/test_utils.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

-cassandra_merge_test: utilities/merge_operators/cassandra/cassandra_merge_test.o utilities/merge_operators/cassandra/test_utils.o $(LIBOBJECTS) $(TESTHARNESS)
+cassandra_functional_test: utilities/cassandra/cassandra_functional_test.o utilities/cassandra/test_utils.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

-cassandra_row_merge_test: utilities/merge_operators/cassandra/cassandra_row_merge_test.o utilities/merge_operators/cassandra/test_utils.o $(LIBOBJECTS) $(TESTHARNESS)
+cassandra_row_merge_test: utilities/cassandra/cassandra_row_merge_test.o utilities/cassandra/test_utils.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

-cassandra_serialize_test: utilities/merge_operators/cassandra/cassandra_serialize_test.o $(LIBOBJECTS) $(TESTHARNESS)
+cassandra_serialize_test: utilities/cassandra/cassandra_serialize_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

 redis_test: utilities/redis/redis_lists_test.o $(LIBOBJECTS) $(TESTHARNESS)
@@ -6,8 +6,6 @@ REPO_PATH = TARGETS_PATH[(TARGETS_PATH.find('fbcode/') + len('fbcode/')):] + "/"
 BUCK_BINS = "buck-out/gen/" + REPO_PATH
 TEST_RUNNER = REPO_PATH + "buckifier/rocks_test_runner.sh"
 rocksdb_compiler_flags = [
-  "-msse",
-  "-msse4.2",
  "-fno-builtin-memcmp",
  "-DROCKSDB_PLATFORM_POSIX",
  "-DROCKSDB_LIB_IO_POSIX",
@@ -16,8 +14,8 @@ rocksdb_compiler_flags = [
  "-DROCKSDB_RANGESYNC_PRESENT",
  "-DROCKSDB_SCHED_GETCPU_PRESENT",
  "-DROCKSDB_SUPPORT_THREAD_LOCAL",
-  "-DHAVE_SSE42",
  "-DOS_LINUX",
+  "-DROCKSDB_UBSAN_RUN",
  # Flags to enable libs we include
  "-DSNAPPY",
  "-DZLIB",
@@ -49,6 +47,10 @@ rocksdb_preprocessor_flags = [
  "-I" + REPO_PATH,
 ]

+rocksdb_arch_preprocessor_flags = {
+  "x86_64": ["-DHAVE_SSE42"],
+}
+
 cpp_library(
    name = "rocksdb_lib",
    headers = AutoHeaders.RECURSIVE_GLOB,
@@ -212,6 +214,9 @@ cpp_library(
      "utilities/blob_db/blob_log_writer.cc",
      "utilities/blob_db/blob_log_format.cc",
      "utilities/blob_db/ttl_extractor.cc",
+      "utilities/cassandra/cassandra_compaction_filter.cc",
+      "utilities/cassandra/format.cc",
+      "utilities/cassandra/merge_operator.cc",
      "utilities/checkpoint/checkpoint_impl.cc",
      "utilities/compaction_filters/remove_emptyvalue_compactionfilter.cc",
      "utilities/convenience/info_log_finder.cc",
@@ -226,8 +231,6 @@ cpp_library(
      "utilities/leveldb_options/leveldb_options.cc",
      "utilities/lua/rocks_lua_compaction_filter.cc",
      "utilities/memory/memory_util.cc",
-      "utilities/merge_operators/cassandra/format.cc",
-      "utilities/merge_operators/cassandra/merge_operator.cc",
      "utilities/merge_operators/max.cc",
      "utilities/merge_operators/put.cc",
      "utilities/merge_operators/string_append/stringappend.cc",
@@ -245,13 +248,14 @@ cpp_library(
      "utilities/spatialdb/spatial_db.cc",
      "utilities/table_properties_collectors/compact_on_deletion_collector.cc",
      "utilities/transactions/optimistic_transaction_db_impl.cc",
-      "utilities/transactions/optimistic_transaction_impl.cc",
+      "utilities/transactions/optimistic_transaction.cc",
      "utilities/transactions/transaction_base.cc",
-      "utilities/transactions/transaction_db_impl.cc",
+      "utilities/transactions/pessimistic_transaction_db.cc",
      "utilities/transactions/transaction_db_mutex_impl.cc",
-      "utilities/transactions/transaction_impl.cc",
+      "utilities/transactions/pessimistic_transaction.cc",
      "utilities/transactions/transaction_lock_mgr.cc",
      "utilities/transactions/transaction_util.cc",
+      "utilities/transactions/write_prepared_txn.cc",
      "utilities/ttl/db_ttl_impl.cc",
      "utilities/write_batch_with_index/write_batch_with_index.cc",
      "utilities/write_batch_with_index/write_batch_with_index_internal.cc",
@@ -262,6 +266,7 @@ cpp_library(
    ],
    deps = [],
    preprocessor_flags = rocksdb_preprocessor_flags,
+    arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
    compiler_flags = rocksdb_compiler_flags,
    external_deps = rocksdb_external_deps,
 )
@@ -275,13 +280,14 @@ cpp_library(
      "util/testharness.cc",
      "util/testutil.cc",
      "db/db_test_util.cc",
-      "utilities/merge_operators/cassandra/test_utils.cc",
+      "utilities/cassandra/test_utils.cc",
      "utilities/col_buf_encoder.cc",
      "utilities/col_buf_decoder.cc",
      "utilities/column_aware_encoding_util.cc",
    ],
    deps = [":rocksdb_lib"],
    preprocessor_flags = rocksdb_preprocessor_flags,
+    arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
    compiler_flags = rocksdb_compiler_flags,
    external_deps = rocksdb_external_deps,
 )
@@ -295,6 +301,7 @@ cpp_library(
    ],
    deps = [":rocksdb_lib"],
    preprocessor_flags = rocksdb_preprocessor_flags,
+    arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
    compiler_flags = rocksdb_compiler_flags,
    external_deps = rocksdb_external_deps,
 )
@@ -305,6 +312,7 @@ cpp_library(
    srcs = ["env/env_basic_test.cc"],
    deps = [":rocksdb_test_lib"],
    preprocessor_flags = rocksdb_preprocessor_flags,
+    arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
    compiler_flags = rocksdb_compiler_flags,
    external_deps = rocksdb_external_deps,
 )
@@ -325,16 +333,16 @@ ROCKS_TESTS = [['arena_test', 'util/arena_test.cc', 'serial'],
 ['c_test', 'db/c_test.c', 'serial'],
 ['cache_test', 'cache/cache_test.cc', 'serial'],
 ['cassandra_format_test',
-  'utilities/merge_operators/cassandra/cassandra_format_test.cc',
+  'utilities/cassandra/cassandra_format_test.cc',
  'serial'],
- ['cassandra_merge_test',
-  'utilities/merge_operators/cassandra/cassandra_merge_test.cc',
+ ['cassandra_functional_test',
+  'utilities/cassandra/cassandra_functional_test.cc',
  'serial'],
 ['cassandra_row_merge_test',
-  'utilities/merge_operators/cassandra/cassandra_row_merge_test.cc',
+  'utilities/cassandra/cassandra_row_merge_test.cc',
  'serial'],
 ['cassandra_serialize_test',
-  'utilities/merge_operators/cassandra/cassandra_serialize_test.cc',
+  'utilities/cassandra/cassandra_serialize_test.cc',
  'serial'],
 ['checkpoint_test', 'utilities/checkpoint/checkpoint_test.cc', 'serial'],
 ['cleanable_test', 'table/cleanable_test.cc', 'serial'],
@@ -500,6 +508,7 @@ for test_cfg in ROCKS_TESTS:
      srcs = [test_cc],
      deps = [":rocksdb_test_lib"],
      preprocessor_flags = rocksdb_preprocessor_flags,
+      arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
      compiler_flags = rocksdb_compiler_flags,
      external_deps = rocksdb_external_deps,
    )
@@ -80,3 +80,6 @@ quasardb uses a heavily tuned RocksDB as its persistence layer.

 ## 360 Pika
 [360](http://www.360.cn/) [Pika](https://github.com/Qihoo360/pika) is a nosql compatible with redis. With the huge amount of data stored, redis may suffer for a capacity bottleneck, and pika was born for solving it. It has widely been widely used in many company
+
+## LzLabs
+LzLabs is using RocksDB as a storage engine in their multi-database distributed framework to store application configuration and user data.
@@ -1,3 +0,0 @@
-<?php
-
-phutil_register_library('arcanist_util', __FILE__);
@@ -1,71 +0,0 @@
-<?php
-
-/**
- * This file is automatically generated. Use 'arc liberate' to rebuild it.
- * @generated
- * @phutil-library-version 2
- */
-
-if (class_exists('ArcanistWorkflow')) {
-  phutil_register_library_map(array(
-    '__library_version__' => 2,
-    'class' =>
-    array(
-      'ArcanistCpplintLinter' => 'cpp_linter/ArcanistCpplintLinter.php',
-      'BaseDirectoryScopedFormatLinter' => 'cpp_linter/BaseDirectoryScopedFormatLinter.php',
-      'FacebookArcanistConfiguration' => 'config/FacebookArcanistConfiguration.php',
-      'FacebookFbcodeLintEngine' => 'lint_engine/FacebookFbcodeLintEngine.php',
-      'FacebookFbcodeUnitTestEngine' => 'unit_engine/FacebookFbcodeUnitTestEngine.php',
-      'FacebookHowtoevenLintEngine' => 'lint_engine/FacebookHowtoevenLintEngine.php',
-      'FacebookHowtoevenLinter' => 'cpp_linter/FacebookHowtoevenLinter.php',
-      'FbcodeClangFormatLinter' => 'cpp_linter/FbcodeClangFormatLinter.php',
-      'FbcodeCppLinter' => 'cpp_linter/FbcodeCppLinter.php',
-    ),
-    'function' =>
-    array(
-    ),
-    'xmap' =>
-    array(
-      'ArcanistCpplintLinter' => 'ArcanistLinter',
-      'BaseDirectoryScopedFormatLinter' => 'ArcanistLinter',
-      'FacebookArcanistConfiguration' => 'ArcanistConfiguration',
-      'FacebookFbcodeLintEngine' => 'ArcanistLintEngine',
-      'FacebookFbcodeUnitTestEngine' => 'ArcanistBaseUnitTestEngine',
-      'FacebookHowtoevenLintEngine' => 'ArcanistLintEngine',
-      'FacebookHowtoevenLinter' => 'ArcanistLinter',
-      'FbcodeClangFormatLinter' => 'BaseDirectoryScopedFormatLinter',
-      'FbcodeCppLinter' => 'ArcanistLinter',
-    ),
-  ));
-} else {
-  phutil_register_library_map(array(
-    '__library_version__' => 2,
-    'class' =>
-    array(
-      'ArcanistCpplintLinter' => 'cpp_linter/ArcanistCpplintLinter.php',
-      'BaseDirectoryScopedFormatLinter' => 'cpp_linter/BaseDirectoryScopedFormatLinter.php',
-      'FacebookArcanistConfiguration' => 'config/FacebookOldArcanistConfiguration.php',
-      'FacebookFbcodeLintEngine' => 'lint_engine/FacebookFbcodeLintEngine.php',
-      'FacebookFbcodeUnitTestEngine' => 'unit_engine/FacebookOldFbcodeUnitTestEngine.php',
-      'FacebookHowtoevenLintEngine' => 'lint_engine/FacebookHowtoevenLintEngine.php',
-      'FacebookHowtoevenLinter' => 'cpp_linter/FacebookHowtoevenLinter.php',
-      'FbcodeClangFormatLinter' => 'cpp_linter/FbcodeClangFormatLinter.php',
-      'FbcodeCppLinter' => 'cpp_linter/FbcodeCppLinter.php',
-    ),
-    'function' =>
-    array(
-    ),
-    'xmap' =>
-    array(
-      'ArcanistCpplintLinter' => 'ArcanistLinter',
-      'BaseDirectoryScopedFormatLinter' => 'ArcanistLinter',
-      'FacebookArcanistConfiguration' => 'ArcanistConfiguration',
-      'FacebookFbcodeLintEngine' => 'ArcanistLintEngine',
-      'FacebookFbcodeUnitTestEngine' => 'ArcanistBaseUnitTestEngine',
-      'FacebookHowtoevenLintEngine' => 'ArcanistLintEngine',
-      'FacebookHowtoevenLinter' => 'ArcanistLinter',
-      'FbcodeClangFormatLinter' => 'BaseDirectoryScopedFormatLinter',
-      'FbcodeCppLinter' => 'ArcanistLinter',
-    ),
-  ));
-}
@@ -1,43 +0,0 @@
-<?php
-// Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-require('RocksDBCommonHelper.php');
-
-define("DIFF_COMMAND", "diff");
-
-class FacebookArcanistConfiguration extends ArcanistConfiguration {
-  public function getCustomArgumentsForCommand($command) {
-    if ($command == "land") {
-      return array(
-          'async' => array('help' => 'Just to make tools happy'));
-    }
-    return array();
-  }
-
-  public function didRunWorkflow($command,
-                                 ArcanistWorkflow $workflow,
-                                 $error_code) {
-    // Default options don't terminate on failure, but that's what we want. In
-    // the current case we use assertions intentionally as "terminate on failure
-    // invariants".
-    assert_options(ASSERT_BAIL, true);
-
-    assert($workflow);
-    assert(strlen($command) > 0);
-
-    if ($command == DIFF_COMMAND && !$workflow->isRawDiffSource()) {
-      $diffID = $workflow->getDiffId();
-
-      // When submitting a diff this code path gets executed multiple times in
-      // a row. We only care about the case when ID for the diff is provided
-      // because that's what we need to apply the diff and trigger the tests.
-      if (strlen($diffID) > 0) {
-        assert(is_numeric($diffID));
-        startTestsInSandcastle(true /* $applyDiff */, $workflow, $diffID);
-      }
-    }
-  }
-}
@@ -1,43 +0,0 @@
-<?php
-// Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-require('RocksDBCommonHelper.php');
-
-define("DIFF_COMMAND", "diff");
-
-class FacebookArcanistConfiguration extends ArcanistConfiguration {
-  public function getCustomArgumentsForCommand($command) {
-    if ($command == "land") {
-      return array(
-          'async' => array('help' => 'Just to make tools happy'));
-    }
-    return array();
-  }
-
-  public function didRunWorkflow($command,
-                                 ArcanistBaseWorkflow $workflow,
-                                 $error_code) {
-    // Default options don't terminate on failure, but that's what we want. In
-    // the current case we use assertions intentionally as "terminate on failure
-    // invariants".
-    assert_options(ASSERT_BAIL, true);
-
-    assert($workflow);
-    assert(strlen($command) > 0);
-
-    if ($command == DIFF_COMMAND && !$workflow->isRawDiffSource()) {
-      $diffID = $workflow->getDiffId();
-
-      // When submitting a diff this code path gets executed multiple times in
-      // a row. We only care about the case when ID for the diff is provided
-      // because that's what we need to apply the diff and trigger the tests.
-      if (strlen($diffID) > 0) {
-        assert(is_numeric($diffID));
-        startTestsInSandcastle(true /* $applyDiff */, $workflow, $diffID);
-      }
-    }
-  }
-}
@@ -1,88 +0,0 @@
-<?php
-
-/**
- * Uses google's cpplint.py to check code. RocksDB team forked this file from
- * phabricator's /src/lint/linter/ArcanistCpplintLinter.php, and customized it
- * for its own use.
- *
- * You can get it here:
- * http://google-styleguide.googlecode.com/svn/trunk/cpplint/cpplint.py
- * @group linter
- */
-final class ArcanistCpplintLinter extends ArcanistLinter {
-
-  public function willLintPaths(array $paths) {
-    return;
-  }
-
-  public function getLinterName() {
-    return 'cpplint.py';
-  }
-
-  public function getLintPath() {
-    $bin = 'cpplint.py';
-    // Search under current dir
-    list($err) = exec_manual('which %s/%s', $this->linterDir(), $bin);
-    if (!$err) {
-      return $this->linterDir().'/'.$bin;
-    }
-
-    // Look for globally installed cpplint.py
-    list($err) = exec_manual('which %s', $bin);
-    if ($err) {
-      throw new ArcanistUsageException(
-        "cpplint.py does not appear to be installed on this system. Install ".
-        "it (e.g., with 'wget \"http://google-styleguide.googlecode.com/".
-        "svn/trunk/cpplint/cpplint.py\"') ".
-        "in your .arcconfig to point to the directory where it resides. ".
-        "Also don't forget to chmod a+x cpplint.py!");
-    }
-
-    return $bin;
-  }
-
-  public function lintPath($path) {
-    $bin = $this->getLintPath();
-    $path = $this->rocksdbDir().'/'.$path;
-
-    $f = new ExecFuture("%C $path", $bin);
-
-    list($err, $stdout, $stderr) = $f->resolve();
-
-    if ($err === 2) {
-      throw new Exception("cpplint failed to run correctly:\n".$stderr);
-    }
-
-    $lines = explode("\n", $stderr);
-    $messages = array();
-    foreach ($lines as $line) {
-      $line = trim($line);
-      $matches = null;
-      $regex = '/^[^:]+:(\d+):\s*(.*)\s*\[(.*)\] \[(\d+)\]$/';
-      if (!preg_match($regex, $line, $matches)) {
-        continue;
-      }
-      foreach ($matches as $key => $match) {
-        $matches[$key] = trim($match);
-      }
-      $message = new ArcanistLintMessage();
-      $message->setPath($path);
-      $message->setLine($matches[1]);
-      $message->setCode($matches[3]);
-      $message->setName($matches[3]);
-      $message->setDescription($matches[2]);
-      $message->setSeverity(ArcanistLintSeverity::SEVERITY_WARNING);
-      $this->addLintMessage($message);
-    }
-  }
-
-  // The path of this linter
-  private function linterDir() {
-    return dirname(__FILE__);
-  }
-
-  // TODO(kaili) a quick and dirty way to figure out rocksdb's root dir.
-  private function rocksdbDir() {
-    return $this->linterDir()."/../..";
-  }
-}
@@ -1,74 +0,0 @@
-<?php
-// Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-abstract class BaseDirectoryScopedFormatLinter extends ArcanistLinter {
-
-  const LINT_FORMATTING = 1;
-
-  private $changedLines = array();
-  private $rawLintOutput = array();
-
-  abstract protected function getPathsToLint();
-
-  protected function shouldLintPath($path) {
-    foreach ($this->getPathsToLint() as $p) {
-      // check if $path starts with $p
-      if (strncmp($path, $p, strlen($p)) === 0) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  // API to tell this linter which lines were changed
-  final public function setPathChangedLines($path, $changed) {
-    $this->changedLines[$path] = $changed;
-  }
-
-  final public function willLintPaths(array $paths) {
-    $futures = array();
-    foreach ($paths as $path) {
-      if (!$this->shouldLintPath($path)) {
-        continue;
-      }
-
-      $changed = $this->changedLines[$path];
-      if (!isset($changed)) {
-        // do not run linter if there are no changes
-        continue;
-      }
-
-      $futures[$path] = $this->getFormatFuture($path, $changed);
-    }
-
-    foreach (id(new FutureIterator($futures))->limit(8) as $p => $f) {
-      $this->rawLintOutput[$p] = $f->resolvex();
-    }
-  }
-
-  abstract protected function getFormatFuture($path, array $changed);
-  abstract protected function getLintMessage($diff);
-
-  final public function lintPath($path) {
-    if (!isset($this->rawLintOutput[$path])) {
-      return;
-    }
-
-    list($new_content) = $this->rawLintOutput[$path];
-    $old_content = $this->getData($path);
-
-    if ($new_content != $old_content) {
-      $diff = ArcanistDiffUtils::renderDifferences($old_content, $new_content);
-      $this->raiseLintAtOffset(
-        0,
-        self::LINT_FORMATTING,
-        $this->getLintMessage($diff),
-        $old_content,
-        $new_content);
-    }
-  }
-
-}
@@ -1,223 +0,0 @@
-<?php
-// Copyright 2015-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-final class FacebookHowtoevenLinter extends ArcanistLinter {
-
-  const VERSION = 'fd9192f324c36d28136d14380f0b552a1385b59b';
-
-  private $parsedTargets = array();
-
-  public function getLinterName() {
-    return 'Howtoeven';
-  }
-
-  protected function getSeverity($code) {
-    $severities = array(
-      ArcanistLintSeverity::SEVERITY_DISABLED,
-      ArcanistLintSeverity::SEVERITY_ADVICE,
-      ArcanistLintSeverity::SEVERITY_WARNING,
-      ArcanistLintSeverity::SEVERITY_ERROR,
-    );
-    return idx($severities, $code, ArcanistLintSeverity::SEVERITY_WARNING);
-  }
-
-  public function willLintPaths(array $paths) {
-    // Cleanup previous runs.
-    $this->localExecx("rm -rf _build/_lint");
-
-    // Build compilation database.
-    $lintable_paths = $this->getLintablePaths($paths);
-    $interesting_paths = $this->getInterestingPaths($lintable_paths);
-
-    if (!$lintable_paths) {
-      return;
-    }
-
-    // Run lint.
-    try {
-      $this->localExecx(
-        "%C %C -p _build/dev/ %Ls",
-        $this->getBinaryPath(),
-        $this->getFilteredIssues(),
-        $lintable_paths);
-    } catch (CommandException $exception) {
-      PhutilConsole::getConsole()->writeErr($exception->getMessage());
-    }
-
-    // Load results.
-    $result = id(
-      new SQLite3(
-        $this->getProjectRoot().'/_build/_lint/lint.db',
-        SQLITE3_OPEN_READONLY))
-      ->query("SELECT * FROM raised_issues");
-
-    while ($issue = $result->fetchArray(SQLITE3_ASSOC)) {
-      // Skip issues not part of the linted file.
-      if (in_array($issue['file'], $interesting_paths)) {
-        $this->addLintMessage(id(new ArcanistLintMessage())
-          ->setPath($issue['file'])
-          ->setLine($issue['line'])
-          ->setChar($issue['column'])
-          ->setCode('Howtoeven')
-          ->setSeverity($this->getSeverity($issue['severity']))
-          ->setName('Hte-'.$issue['name'])
-          ->setDescription(
-            sprintf(
-              "%s\n\n%s",
-              ($issue['message']) ? $issue['message'] : $issue['description'],
-              $issue['explanation']))
-          ->setOriginalText(idx($issue, 'original', ''))
-          ->setReplacementText(idx($issue, 'replacement', '')));
-      }
-    }
-  }
-
-  public function lintPath($path) {
-  }
-
-  /**
-   * Get the paths that we know how to lint.
-   *
-   * The strategy is to first look whether there's an existing compilation
-   * database and use that if it's exhaustive. We generate our own only if
-   * necessary.
-   */
-  private function getLintablePaths($paths) {
-    // Replace headers with existing sources.
-    for ($i = 0; $i < count($paths); $i++) {
-      if (preg_match("/\.h$/", $paths[$i])) {
-        $header = preg_replace("/\.h$/", ".cpp", $paths[$i]);
-        if (file_exists($header)) {
-          $paths[$i] = $header;
-        }
-      }
-    }
-
-    // Check if database exists and is exhaustive.
-    $available_paths = $this->getAvailablePaths();
-    $lintable_paths = array_intersect($paths, $available_paths);
-    if ($paths === $lintable_paths) {
-      return $lintable_paths;
-    }
-
-    // Generate our own database.
-    $targets = $this->getTargetsFor($paths);
-    if (!$targets) {
-      PhutilConsole::getConsole()->writeErr(
-        "No build targets found for %s\n",
-        implode(', ', $paths));
-      return array();
-    }
-
-    $this->localExecx("./tools/build/bin/fbconfig.par -r %Ls", $targets);
-    $this->localExecx("./tools/build/bin/fbmake.par gen_cdb");
-
-    $available_paths = $this->getAvailablePaths();
-    $lintable_paths = array_intersect($paths, $available_paths);
-    if ($paths != $lintable_paths) {
-      PhutilConsole::getConsole()->writeErr(
-        "Can't lint %s\n",
-        implode(', ', array_diff($paths, $available_paths)));
-    }
-
-    // Return what we know how to lint.
-    return $lintable_paths;
-  }
-
-  /**
-   * Get the available paths in the current compilation database.
-   */
-  private function getAvailablePaths() {
-    $database_path = $this->getProjectRoot()
-      .'/_build/dev/compile_commands.json';
-    if (!file_exists($database_path)) {
-      return array();
-    }
-
-    $entries = json_decode(file_get_contents($database_path), true);
-    $paths = array();
-    foreach ($entries as $entry) {
-      $paths[] = $entry['file'];
-    }
-    return $paths;
-  }
-
-  /**
-   * Search for the targets directories for the given files.
-   */
-  private static function getTargetsFor($paths) {
-    $targets = array();
-    foreach ($paths as $path) {
-      while (($path = dirname($path)) !== '.') {
-        if (in_array('TARGETS', scandir($path))) {
-          $contents = file_get_contents($path.'/TARGETS');
-          if (strpos($contents, 'cpp_binary') !== false) {
-            $targets[] = $path;
-            break;
-          }
-        }
-      }
-    }
-    return array_unique($targets);
-  }
-
-  /**
-   * The paths that we actually want to report on.
-   */
-  private function getInterestingPaths($paths) {
-    $headers = array();
-    foreach ($paths as $path) {
-      $headers[] = preg_replace("/\.cpp$/", ".h", $path);
-    }
-    return array_merge($paths, $headers);
-  }
-
-  /**
-   * The path where the binary is located. Will return the current dewey binary
-   * unless the `HOWTOEVEN_BUILD` environment variable is set.
-   */
-  private function getBinaryPath() {
-    $path = sprintf(
-      "/mnt/dewey/fbcode/.commits/%s/builds/howtoeven/client",
-      self::VERSION);
-
-    $build = getenv('HOWTOEVEN_BUILD');
-    if ($build) {
-      $path = sprintf(
-        "./_build/%s/tools/howtoeven/client",
-        $build);
-      if (!file_exists($path)) {
-        PhutilConsole::getConsole()->writeErr(">> %s does not exist\n", $path);
-        exit(1);
-      }
-    }
-
-    return $path;
-  }
-
-  /**
-   * Execute the command in the root directory.
-   */
-  private function localExecx($command /* , ... */) {
-    $arguments = func_get_args();
-    return newv('ExecFuture', $arguments)
-      ->setCWD($this->getProjectRoot())
-      ->resolvex();
-  }
-
-  /**
-   * The root of the project.
-   */
-  private function getProjectRoot() {
-    return $this->getEngine()->getWorkingCopy()->getProjectRoot();
-  }
-
-  private function getFilteredIssues() {
-    $issues = getenv('HOWTOEVEN_ISSUES');
-    return ($issues) ? csprintf('-issues %s', $issues) : '';
-  }
-
-}
@@ -1,58 +0,0 @@
-<?php
-// Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-final class FbcodeClangFormatLinter extends BaseDirectoryScopedFormatLinter {
-
-  const LINT_FORMATTING = 1;
-  const CLANG_FORMAT_BINARY = '/mnt/vol/engshare/admin/scripts/clang-format';
-
-  protected function getPathsToLint() {
-    return array('');
-  }
-
-  public function getLinterName() {
-    return 'CLANG_FORMAT';
-  }
-
-  public function getLintSeverityMap() {
-    return array(
-      self::LINT_FORMATTING => ArcanistLintSeverity::SEVERITY_ADVICE,
-    );
-  }
-
-  public function getLintNameMap() {
-    return array(
-      self::LINT_FORMATTING => pht('Changes are not clang-formatted'),
-    );
-  }
-
-  protected function getFormatFuture($path, array $changed) {
-    $args = "";
-    foreach ($changed as $key => $value) {
-      $args .= " --lines=$key:$key";
-    }
-
-    $binary = self::CLANG_FORMAT_BINARY;
-    if (!file_exists($binary)) {
-      // trust the $PATH
-      $binary = "clang-format";
-    }
-
-    return new ExecFuture(
-      "%s %s $args",
-      $binary,
-      $this->getEngine()->getFilePathOnDisk($path));
-  }
-
-  protected function getLintMessage($diff) {
-    $link_to_clang_format =
-      "[[ http://fburl.com/clang-format | clang-format ]]";
-    return <<<LINT_MSG
-Changes in this file were not formatted using $link_to_clang_format.
-Please run build_tools/format-diff.sh or `make format`
-LINT_MSG;
-  }
-}
@@ -1,126 +0,0 @@
-<?php
-// Copyright 2004-present Facebook.  All rights reserved.
-
-class FbcodeCppLinter extends ArcanistLinter {
-  const FLINT      = "/home/engshare/tools/flint";
-  const LINT_ERROR   = 1;
-  const LINT_WARNING = 2;
-  const LINT_ADVICE  = 3;
-  const C_FLAG = "--c_mode=true";
-
-  private $rawLintOutput = array();
-
-  public function willLintPaths(array $paths) {
-    if (!file_exists(self::FLINT)) {
-      return;
-    }
-    $futures = array();
-    foreach ($paths as $p) {
-      $lpath = $this->getEngine()->getFilePathOnDisk($p);
-      $lpath_file = file($lpath);
-      if (preg_match('/\.(c)$/', $lpath) ||
-          preg_match('/-\*-.*Mode: C[; ].*-\*-/', $lpath_file[0]) ||
-          preg_match('/vim(:.*)*:\s*(set\s+)?filetype=c\s*:/', $lpath_file[0])
-          ) {
-        $futures[$p] = new ExecFuture("%s %s %s 2>&1",
-                           self::FLINT, self::C_FLAG,
-                           $this->getEngine()->getFilePathOnDisk($p));
-      } else {
-        $futures[$p] = new ExecFuture("%s %s 2>&1",
-          self::FLINT, $this->getEngine()->getFilePathOnDisk($p));
-      }
-    }
-
-    foreach (Futures($futures)->limit(8) as $p => $f) {
-      $this->rawLintOutput[$p] = $f->resolvex();
-    }
-
-    return;
-  }
-
-  public function getLinterName() {
-    return "FBCPP";
-  }
-
-  public function lintPath($path) {
-    $this->runCppLint($path);
-  }
-
-  private function runCppLint($path) {
-    $msgs = $this->getCppLintOutput($path);
-    foreach ($msgs as $m) {
-      $this->raiseLintAtLine($m['line'], 0, $m['severity'], $m['msg']);
-    }
-  }
-
-  private function adviseOnEachPattern(
-    $path,
-    $regex,
-    $message,
-    $lint_type = self::LINT_ADVICE,
-    $match_idx = 0) {
-      $file_data = $this->getData($path);
-      $matches = array();
-      if (!preg_match_all($regex, $file_data, $matches, PREG_OFFSET_CAPTURE)) {
-        return;
-      }
-
-      foreach ($matches[$match_idx] as $match) {
-        list($match_str, $offset) = $match;
-        $this->raiseLintAtOffset($offset, $lint_type, $message, $match_str);
-      }
-  }
-
-  public function getLintSeverityMap() {
-    return array(
-      self::LINT_WARNING => ArcanistLintSeverity::SEVERITY_WARNING,
-      self::LINT_ADVICE  => ArcanistLintSeverity::SEVERITY_ADVICE,
-      self::LINT_ERROR   => ArcanistLintSeverity::SEVERITY_ERROR
-    );
-  }
-
-  public function getLintNameMap() {
-    return array(
-      self::LINT_ADVICE   => "CppLint Advice",
-      self::LINT_WARNING  => "CppLint Warning",
-      self::LINT_ERROR    => "CppLint Error"
-    );
-  }
-
-  private function getCppLintOutput($path) {
-     if (!array_key_exists($path, $this->rawLintOutput)) {
-       return array();
-     }
-    list($output) = $this->rawLintOutput[$path];
-
-    $msgs = array();
-    $current = null;
-    $matches = array();
-    foreach (explode("\n", $output) as $line) {
-      if (preg_match('/.*?:(\d+):(.*)/', $line, $matches)) {
-        if ($current) {
-          $msgs[] = $current;
-        }
-        $line = $matches[1];
-        $text = $matches[2];
-        if (preg_match('/.*Warning.*/', $text)) {
-          $sev = self::LINT_WARNING;
-        } else if (preg_match('/.*Advice.*/', $text)) {
-          $sev = self::LINT_ADVICE;
-        } else {
-          $sev = self::LINT_ERROR;
-        }
-        $current = array('line'     => $line,
-                         'msg'      => $text,
-                         'severity' => $sev);
-      } else if ($current) {
-        $current['msg'] .= ' ' . $line;
-      }
-    }
-    if ($current) {
-      $msgs[] = $current;
-    }
-
-    return $msgs;
-  }
-}
@@ -1,138 +0,0 @@
-<?php
-// Copyright 2004-present Facebook.  All rights reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-class FacebookFbcodeLintEngine extends ArcanistLintEngine {
-
-  public function buildLinters() {
-    $linters = array();
-    $paths = $this->getPaths();
-
-    // Remove all deleted files, which are not checked by the
-    // following linters.
-    foreach ($paths as $key => $path) {
-      if (!Filesystem::pathExists($this->getFilePathOnDisk($path))) {
-        unset($paths[$key]);
-      }
-    }
-
-    $generated_linter = new ArcanistGeneratedLinter();
-    $linters[] = $generated_linter;
-
-    $nolint_linter = new ArcanistNoLintLinter();
-    $linters[] = $nolint_linter;
-
-    $text_linter = new ArcanistTextLinter();
-    $text_linter->setCustomSeverityMap(array(
-      ArcanistTextLinter::LINT_LINE_WRAP
-        => ArcanistLintSeverity::SEVERITY_ADVICE,
-    ));
-    $linters[] = $text_linter;
-
-    $java_text_linter = new ArcanistTextLinter();
-    $java_text_linter->setMaxLineLength(100);
-    $java_text_linter->setCustomSeverityMap(array(
-      ArcanistTextLinter::LINT_LINE_WRAP
-        => ArcanistLintSeverity::SEVERITY_ADVICE,
-    ));
-    $linters[] = $java_text_linter;
-
-    $python_linter = new ArcanistPEP8Linter();
-    $linters[] = $python_linter;
-
-    $cpp_linters = array();
-    $cpp_linters[] = $linters[] = new ArcanistCpplintLinter();
-    $cpp_linters[] = $linters[] = new FbcodeCppLinter();
-
-    $clang_format_linter = new FbcodeClangFormatLinter();
-    $linters[] = $clang_format_linter;
-
-    $spelling_linter = new ArcanistSpellingLinter();
-    $linters[] = $spelling_linter;
-
-    foreach ($paths as $path) {
-      $is_text = false;
-
-      $text_extensions = (
-        '/\.('.
-        'cpp|cxx|c|cc|h|hpp|hxx|tcc|'.
-        'py|rb|hs|pl|pm|tw|'.
-        'php|phpt|css|js|'.
-        'java|'.
-        'thrift|'.
-        'lua|'.
-        'siv|'.
-        'txt'.
-        ')$/'
-      );
-      if (preg_match($text_extensions, $path)) {
-        $is_text = true;
-      }
-      if ($is_text) {
-        $nolint_linter->addPath($path);
-
-        $generated_linter->addPath($path);
-        $generated_linter->addData($path, $this->loadData($path));
-
-        if (preg_match('/\.java$/', $path)) {
-          $java_text_linter->addPath($path);
-          $java_text_linter->addData($path, $this->loadData($path));
-        } else {
-          $text_linter->addPath($path);
-          $text_linter->addData($path, $this->loadData($path));
-        }
-
-        $spelling_linter->addPath($path);
-        $spelling_linter->addData($path, $this->loadData($path));
-      }
-      if (preg_match('/\.(cpp|c|cc|cxx|h|hh|hpp|hxx|tcc)$/', $path)
-          && !preg_match('/third-party/', $path)) {
-        foreach ($cpp_linters as &$linter) {
-          $linter->addPath($path);
-          $linter->addData($path, $this->loadData($path));
-        }
-
-        $clang_format_linter->addPath($path);
-        $clang_format_linter->addData($path, $this->loadData($path));
-        $clang_format_linter->setPathChangedLines(
-          $path, $this->getPathChangedLines($path));
-      }
-
-      // Match *.py and contbuild config files
-      if (preg_match('/(\.(py|tw|smcprops)|^contbuild\/configs\/[^\/]*)$/',
-                    $path)) {
-        $space_count = 4;
-        $real_path = $this->getFilePathOnDisk($path);
-        $dir = dirname($real_path);
-        do {
-          if (file_exists($dir.'/.python2space')) {
-            $space_count = 2;
-            break;
-          }
-          $dir = dirname($dir);
-        } while ($dir != '/' && $dir != '.');
-
-        $cur_path_linter = $python_linter;
-        $cur_path_linter->addPath($path);
-        $cur_path_linter->addData($path, $this->loadData($path));
-
-        if (preg_match('/\.tw$/', $path)) {
-          $cur_path_linter->setCustomSeverityMap(array(
-            'E251' => ArcanistLintSeverity::SEVERITY_DISABLED,
-          ));
-        }
-      }
-    }
-
-    $name_linter = new ArcanistFilenameLinter();
-    $linters[] = $name_linter;
-    foreach ($paths as $path) {
-      $name_linter->addPath($path);
-    }
-
-    return $linters;
-  }
-
-}
@@ -1,27 +0,0 @@
-<?php
-// Copyright 2015-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-final class FacebookHowtoevenLintEngine extends ArcanistLintEngine {
-
-  public function buildLinters() {
-    $paths = array();
-
-    foreach ($this->getPaths() as $path) {
-      // Don't try to lint deleted files or changed directories.
-      if (!Filesystem::pathExists($path) || is_dir($path)) {
-        continue;
-      }
-
-      if (preg_match('/\.(cpp|c|cc|cxx|h|hh|hpp|hxx|tcc)$/', $path)) {
-        $paths[] = $path;
-      }
-    }
-
-    $howtoeven = new FacebookHowtoevenLinter();
-    $howtoeven->setPaths($paths);
-    return array($howtoeven);
-  }
-}
@@ -1,17 +0,0 @@
-<?php
-// Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-class FacebookFbcodeUnitTestEngine extends ArcanistUnitTestEngine {
-
-  public function run() {
-      // For a call to `arc call-conduit differential.updateunitresults` to
-      // succeed we need at least one entry here.
-      $result = new ArcanistUnitTestResult();
-      $result->setName("dummy_placeholder_entry");
-      $result->setResult(ArcanistUnitTestResult::RESULT_PASS);
-      return array($result);
-  }
-}
@@ -1,17 +0,0 @@
-<?php
-// Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-
-class FacebookFbcodeUnitTestEngine extends ArcanistBaseUnitTestEngine {
-
-  public function run() {
-      // For a call to `arc call-conduit differential.updateunitresults` to
-      // succeed we need at least one entry here.
-      $result = new ArcanistUnitTestResult();
-      $result->setName("dummy_placeholder_entry");
-      $result->setResult(ArcanistUnitTestResult::RESULT_PASS);
-      return array($result);
-  }
-}
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Create a tmp directory for the test to use
 TEST_DIR=$(mktemp -d /dev/shm/fbcode_rocksdb_XXXXXXX)
 TEST_TMPDIR="$TEST_DIR" $@ && rm -rf "$TEST_DIR"
@@ -6,12 +6,10 @@ rocksdb_target_header = """
 import os

 TARGETS_PATH = os.path.dirname(__file__)
-REPO_PATH = TARGETS_PATH[(TARGETS_PATH.find('fbcode/') + len('fbcode/')):] + "/"
+REPO_PATH = "rocksdb/src/"
 BUCK_BINS = "buck-out/gen/" + REPO_PATH
 TEST_RUNNER = REPO_PATH + "buckifier/rocks_test_runner.sh"
 rocksdb_compiler_flags = [
-  "-msse",
-  "-msse4.2",
  "-fno-builtin-memcmp",
  "-DROCKSDB_PLATFORM_POSIX",
  "-DROCKSDB_LIB_IO_POSIX",
@@ -20,7 +18,6 @@ rocksdb_compiler_flags = [
  "-DROCKSDB_RANGESYNC_PRESENT",
  "-DROCKSDB_SCHED_GETCPU_PRESENT",
  "-DROCKSDB_SUPPORT_THREAD_LOCAL",
-  "-DHAVE_SSE42",
  "-DOS_LINUX",
  # Flags to enable libs we include
  "-DSNAPPY",
@@ -52,6 +49,10 @@ rocksdb_preprocessor_flags = [
  "-I" + REPO_PATH + "include/",
  "-I" + REPO_PATH,
 ]
+
+rocksdb_arch_preprocessor_flags = {
+  "x86_64": ["-DHAVE_SSE42"],
+}
 """


@@ -62,6 +63,7 @@ cpp_library(
    srcs = [%s],
    deps = [%s],
    preprocessor_flags = rocksdb_preprocessor_flags,
+    arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
    compiler_flags = rocksdb_compiler_flags,
    external_deps = rocksdb_external_deps,
 )
@@ -73,6 +75,7 @@ cpp_binary(
  srcs = [%s],
  deps = [%s],
  preprocessor_flags = rocksdb_preprocessor_flags,
+  arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
  compiler_flags = rocksdb_compiler_flags,
  external_deps = rocksdb_external_deps,
 )
@@ -95,6 +98,7 @@ for test_cfg in ROCKS_TESTS:
      srcs = [test_cc],
      deps = [":rocksdb_test_lib"],
      preprocessor_flags = rocksdb_preprocessor_flags,
+      arch_preprocessor_flags = rocksdb_arch_preprocessor_flags,
      compiler_flags = rocksdb_compiler_flags,
      external_deps = rocksdb_external_deps,
    )
@@ -1,8 +1,8 @@
 <?php
 // Copyright 2004-present Facebook. All Rights Reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
+//  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).

 // Name of the environment variables which need to be set by the entity which
 // triggers continuous runs so that code at the end of the file gets executed
@@ -21,11 +21,17 @@ function postURL($diffID, $url) {
  assert(is_numeric($diffID));
  assert(strlen($url) > 0);

-  $cmd = 'echo \'{"diff_id": ' . $diffID . ', '
-         . '"name":"click here for sandcastle tests for D' . $diffID . '", '
-         . '"link":"' . $url . '"}\' | '
-         . 'arc call-conduit '
-         . 'differential.updateunitresults';
+  $cmd_args = array(
+    'diff_id' => (int)$diffID,
+    'name' => sprintf(
+      'click here for sandcastle tests for D%d',
+      (int)$diffID
+    ),
+    'link' => $url
+  );
+  $cmd = 'echo ' . escapeshellarg(json_encode($cmd_args))
+         . ' | arc call-conduit differential.updateunitresults';
+
  shell_exec($cmd);
 }

@@ -35,11 +41,15 @@ function buildUpdateTestStatusCmd($diffID, $test, $status) {
  assert(strlen($test) > 0);
  assert(strlen($status) > 0);

-  $cmd = 'echo \'{"diff_id": ' . $diffID . ', '
-         . '"name":"' . $test . '", '
-         . '"result":"' . $status . '"}\' | '
-         . 'arc call-conduit '
-         . 'differential.updateunitresults';
+  $cmd_args = array(
+    'diff_id' => (int)$diffID,
+    'name' => $test,
+    'result' => $status
+  );
+
+  $cmd = 'echo ' . escapeshellarg(json_encode($cmd_args))
+         . ' | arc call-conduit differential.updateunitresults';
+
  return $cmd;
 }

@@ -68,7 +78,7 @@ function getSteps($applyDiff, $diffID, $username, $test) {
    // and authenticate using that in Sandcastle.
    $setup = array(
      "name" => "Setup arcrc",
-      "shell" => "echo " . $arcrc_content . " | base64 --decode"
+      "shell" => "echo " . escapeshellarg($arcrc_content) . " | base64 --decode"
                 . " | gzip -d > ~/.arcrc",
      "user" => "root"
    );
@@ -94,7 +104,17 @@ function getSteps($applyDiff, $diffID, $username, $test) {
    "user" => "root"
  );

+  // This fixes "FATAL: ThreadSanitizer can not mmap the shadow memory"
+  // Source:
+  // https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManual#FAQ
+  $fix_kernel_issue = array(
+    "name" => "Fix kernel issue with tsan",
+    "shell" => "echo 2 >/proc/sys/kernel/randomize_va_space",
+    "user" => "root"
+  );
+
  $steps[] = $fix_git_ignore;
+  $steps[] = $fix_kernel_issue;

  // This will be the command used to execute particular type of tests.
  $cmd = "";
@@ -104,7 +124,7 @@ function getSteps($applyDiff, $diffID, $username, $test) {
    $patch = array(
      "name" => "Patch " . $diffID,
      "shell" => "arc --arcrc-file ~/.arcrc "
-                  . "patch --nocommit --diff " . $diffID,
+                  . "patch --nocommit --diff " . escapeshellarg($diffID),
      "user" => "root"
    );

@@ -115,8 +135,8 @@ function getSteps($applyDiff, $diffID, $username, $test) {
  }

  // Run the actual command.
-  $cmd = $cmd . "J=$(nproc) ./build_tools/precommit_checker.py " . $test
-           . "; exit_code=$?; ";
+  $cmd = $cmd . "J=$(nproc) ./build_tools/precommit_checker.py " .
+           escapeshellarg($test) . "; exit_code=$?; ";

  if ($applyDiff) {
    $cmd = $cmd . "([[ \$exit_code -eq 0 ]] &&"
@@ -149,7 +169,7 @@ function getSteps($applyDiff, $diffID, $username, $test) {
    "name" => "Run " . $test,
    "shell" => $cmd,
    "user" => "root",
-    "parser" => "python build_tools/error_filter.py " . $test,
+    "parser" => "python build_tools/error_filter.py " . escapeshellarg($test),
  );

  $steps[] = $run_test;
@@ -197,7 +217,7 @@ function getSandcastleConfig() {
    if (file_exists(PRIMARY_TOKEN_FILE)) {
      $cmd = 'cat ' . PRIMARY_TOKEN_FILE;
    } else {
-      $cmd = 'cat ' . $cwd_token_file;
+      $cmd = 'cat ' . escapeshellarg($cwd_token_file);
    }

    assert(strlen($cmd) > 0);
@@ -241,7 +261,7 @@ function getSandcastleConfig() {
  // List of tests we want to run in Sandcastle.
  $tests = array("unit", "unit_non_shm", "unit_481", "clang_unit", "tsan",
                 "asan", "lite_test", "valgrind", "release", "release_481",
-                 "clang_release", "punit", "clang_analyze", "code_cov",
+                 "clang_release", "clang_analyze", "code_cov",
                 "java_build", "no_compression", "unity", "ubsan");

  $send_email_template = array(
@@ -321,9 +341,11 @@ function getSandcastleConfig() {
  $app = $sandcastle_config[0];
  $token = $sandcastle_config[1];

-  $cmd = 'curl -s -k -F app=' . $app . ' '
-          . '-F token=' . $token . ' -F job=\'' . json_encode($job)
-          .'\' "' . $url . '"';
+  $cmd = 'curl -s -k '
+          . ' -F app=' . escapeshellarg($app)
+          . ' -F token=' . escapeshellarg($token)
+          . ' -F job=' . escapeshellarg(json_encode($job))
+          .' ' . escapeshellarg($url);

  $output = shell_exec($cmd);
  assert(strlen($output) > 0);
@@ -51,13 +51,11 @@ if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
    FBCODE_BUILD="true"
    # If we're compiling with TSAN we need pic build
    PIC_BUILD=$COMPILE_WITH_TSAN
-    if [ -n "$ROCKSDB_FBCODE_BUILD_WITH_481" ]; then
-      # we need this to build with MySQL. Don't use for other purposes.
-      source "$PWD/build_tools/fbcode_config4.8.1.sh"
-    elif [ -n "$ROCKSDB_FBCODE_BUILD_WITH_5xx" ]; then
+    if [ -z "$ROCKSDB_FBCODE_BUILD_WITH_481" ]; then
      source "$PWD/build_tools/fbcode_config.sh"
    else
-      source "$PWD/build_tools/fbcode_config_platform007.sh"
+      # we need this to build with MySQL. Don't use for other purposes.
+      source "$PWD/build_tools/fbcode_config4.8.1.sh"
    fi
 fi

@@ -319,9 +317,11 @@ EOF
    # Test whether jemalloc is available
    if echo 'int main() {}' | $CXX $CFLAGS -x c++ - -o /dev/null -ljemalloc \
      2>/dev/null; then
-        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -ljemalloc"
-        JAVA_LDFLAGS="$JAVA_LDFLAGS -ljemalloc"
+        # This will enable some preprocessor identifiers in the Makefile
        JEMALLOC=1
+        # JEMALLOC can be enabled either using the flag (like here) or by
+        # providing direct link to the jemalloc library
+        WITH_JEMALLOC_FLAG=1
    else
        # jemalloc is not available. Let's try tcmalloc
        if echo 'int main() {}' | $CXX $CFLAGS -x c++ - -o /dev/null \
@@ -458,7 +458,7 @@ elif test -z "$PORTABLE"; then
  fi
 fi

-$CXX $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
  #include <cstdint>
  #include <nmmintrin.h>
  int main() {
@@ -519,7 +519,14 @@ echo "ROCKSDB_PATCH=$ROCKSDB_PATCH" >> "$OUTPUT"
 echo "CLANG_SCAN_BUILD=$CLANG_SCAN_BUILD" >> "$OUTPUT"
 echo "CLANG_ANALYZER=$CLANG_ANALYZER" >> "$OUTPUT"
 echo "PROFILING_FLAGS=$PROFILING_FLAGS" >> "$OUTPUT"
+# This will enable some related identifiers for the preprocessor
 if test -n "$JEMALLOC"; then
  echo "JEMALLOC=1" >> "$OUTPUT"
 fi
+# Indicates that jemalloc should be enabled using -ljemalloc flag
+# The alternative is to porvide a direct link to the library via JEMALLOC_LIB
+# and JEMALLOC_INCLUDE
+if test -n "$WITH_JEMALLOC_FLAG"; then
+  echo "WITH_JEMALLOC_FLAG=$WITH_JEMALLOC_FLAG" >> "$OUTPUT"
+fi
 echo "LUA_PATH=$LUA_PATH" >> "$OUTPUT"
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (c) 2016, Facebook. All rights reserved.
 #
@@ -67,7 +67,7 @@ function update_repo_status {
 #

 # Path to the determinator from the root of the RocksDB repo.
-CONTRUN_DETERMINATOR=./arcanist_util/config/RocksDBCommonHelper.php
+CONTRUN_DETERMINATOR=./build_tools/RocksDBCommonHelper.php

 # Value of the previous commit.
 PREV_COMMIT=
@@ -1,18 +0,0 @@
-GCC_BASE=/mnt/gvfs/third-party2/gcc/6e8e715624fd15256a7970073387793dfcf79b46/7.x/centos7-native/b2ef2b6
-CLANG_BASE=/mnt/gvfs/third-party2/llvm-fb/ef37e1faa1c29782abfac1ae65a291b9b7966f6d/stable/centos7-native/c9f9104
-LIBGCC_BASE=/mnt/gvfs/third-party2/libgcc/c67031f0f739ac61575a061518d6ef5038f99f90/7.x/platform007/5620abc
-GLIBC_BASE=/mnt/gvfs/third-party2/glibc/60d6f124a78798b73944f5ba87c2306ae3460153/2.26/platform007/f259413
-SNAPPY_BASE=/mnt/gvfs/third-party2/snappy/7f9bdaada18f59bc27ec2b0871eb8a6144343aef/1.1.3/platform007/ca4da3d
-ZLIB_BASE=/mnt/gvfs/third-party2/zlib/22c2d65676fb7c23cfa797c4f6937f38b026f3cf/1.2.8/platform007/ca4da3d
-BZIP2_BASE=/mnt/gvfs/third-party2/bzip2/dc49a21c5fceec6456a7a28a94dcd16690af1337/1.0.6/platform007/ca4da3d
-LZ4_BASE=/mnt/gvfs/third-party2/lz4/907b498203d297947f3bb70b9466f47e100f1873/r131/platform007/ca4da3d
-ZSTD_BASE=/mnt/gvfs/third-party2/zstd/3ee276cbacfad3074e3f07bf826ac47f06970f4e/1.3.5/platform007/15a3614
-GFLAGS_BASE=/mnt/gvfs/third-party2/gflags/0b9929d2588991c65a57168bf88aff2db87c5d48/2.2.0/platform007/ca4da3d
-JEMALLOC_BASE=/mnt/gvfs/third-party2/jemalloc/9c910d36d6235cc40e8ff559358f1833452300ca/master/platform007/5b0f53e
-NUMA_BASE=/mnt/gvfs/third-party2/numa/9cbf2460284c669ed19c3ccb200a71f7dd7e53c7/2.0.11/platform007/ca4da3d
-LIBUNWIND_BASE=/mnt/gvfs/third-party2/libunwind/bf3d7497fe4e6d007354f0adffa16ce3003f8338/1.3/platform007/6f3e0a9
-TBB_BASE=/mnt/gvfs/third-party2/tbb/ff4e0b093534704d8abab678a4fd7f5ea7b094c7/2018_U5/platform007/ca4da3d
-KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/b5c4a61a5c483ba24722005ae07895971a2ac707/fb/platform007/da39a3e
-BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/92ff90349e2f43ea0a8246d8b1cf17b6869013e3/2.29.1/centos7-native/da39a3e
-VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/f3f697a28122e6bcd513273dd9c1ff23852fc59f/3.13.0/platform007/ca4da3d
-LUA_BASE=/mnt/gvfs/third-party2/lua/f0cd714433206d5139df61659eb7b28b1dea6683/5.3.4/platform007/5007832
@@ -1,2 +1,2 @@
-#!/bin/bash
+#!/usr/bin/env bash
 docker run -v $PWD:/rocks -w /rocks buildpack-deps make
@@ -1,157 +0,0 @@
-#!/bin/sh
-#
-# Set environment variables so that we can compile rocksdb using
-# fbcode settings.  It uses the latest g++ and clang compilers and also
-# uses jemalloc
-# Environment variables that change the behavior of this script:
-# PIC_BUILD -- if true, it will only take pic versions of libraries from fbcode. libraries that don't have pic variant will not be included
-
-
-BASEDIR=`dirname $BASH_SOURCE`
-source "$BASEDIR/dependencies_platform007.sh"
-
-CFLAGS=""
-
-# libgcc
-LIBGCC_INCLUDE="$LIBGCC_BASE/include/c++/7.3.0"
-LIBGCC_LIBS=" -L $LIBGCC_BASE/lib"
-
-# glibc
-GLIBC_INCLUDE="$GLIBC_BASE/include"
-GLIBC_LIBS=" -L $GLIBC_BASE/lib"
-
-# snappy
-SNAPPY_INCLUDE=" -I $SNAPPY_BASE/include/"
-if test -z $PIC_BUILD; then
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy.a"
-else
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy_pic.a"
-fi
-CFLAGS+=" -DSNAPPY"
-
-if test -z $PIC_BUILD; then
-  # location of zlib headers and libraries
-  ZLIB_INCLUDE=" -I $ZLIB_BASE/include/"
-  ZLIB_LIBS=" $ZLIB_BASE/lib/libz.a"
-  CFLAGS+=" -DZLIB"
-
-  # location of bzip headers and libraries
-  BZIP_INCLUDE=" -I $BZIP2_BASE/include/"
-  BZIP_LIBS=" $BZIP2_BASE/lib/libbz2.a"
-  CFLAGS+=" -DBZIP2"
-
-  LZ4_INCLUDE=" -I $LZ4_BASE/include/"
-  LZ4_LIBS=" $LZ4_BASE/lib/liblz4.a"
-  CFLAGS+=" -DLZ4"
-fi
-
-ZSTD_INCLUDE=" -I $ZSTD_BASE/include/"
-if test -z $PIC_BUILD; then
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd.a"
-else
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd_pic.a"
-fi
-CFLAGS+=" -DZSTD"
-
-# location of gflags headers and libraries
-GFLAGS_INCLUDE=" -I $GFLAGS_BASE/include/"
-if test -z $PIC_BUILD; then
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags.a"
-else
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags_pic.a"
-fi
-CFLAGS+=" -DGFLAGS=gflags"
-
-# location of jemalloc
-JEMALLOC_INCLUDE=" -I $JEMALLOC_BASE/include/"
-JEMALLOC_LIB=" $JEMALLOC_BASE/lib/libjemalloc.a"
-
-if test -z $PIC_BUILD; then
-  # location of numa
-  NUMA_INCLUDE=" -I $NUMA_BASE/include/"
-  NUMA_LIB=" $NUMA_BASE/lib/libnuma.a"
-  CFLAGS+=" -DNUMA"
-
-  # location of libunwind
-  LIBUNWIND="$LIBUNWIND_BASE/lib/libunwind.a"
-fi
-
-# location of TBB
-TBB_INCLUDE=" -isystem $TBB_BASE/include/"
-if test -z $PIC_BUILD; then
-  TBB_LIBS="$TBB_BASE/lib/libtbb.a"
-else
-  TBB_LIBS="$TBB_BASE/lib/libtbb_pic.a"
-fi
-CFLAGS+=" -DTBB"
-
-# use Intel SSE support for checksum calculations
-export USE_SSE=1
-export PORTABLE=1
-
-BINUTILS="$BINUTILS_BASE/bin"
-AR="$BINUTILS/ar"
-
-DEPS_INCLUDE="$SNAPPY_INCLUDE $ZLIB_INCLUDE $BZIP_INCLUDE $LZ4_INCLUDE $ZSTD_INCLUDE $GFLAGS_INCLUDE $NUMA_INCLUDE $TBB_INCLUDE"
-
-STDLIBS="-L $GCC_BASE/lib64"
-
-CLANG_BIN="$CLANG_BASE/bin"
-CLANG_LIB="$CLANG_BASE/lib"
-CLANG_SRC="$CLANG_BASE/../../src"
-
-CLANG_ANALYZER="$CLANG_BIN/clang++"
-CLANG_SCAN_BUILD="$CLANG_SRC/llvm/tools/clang/tools/scan-build/bin/scan-build"
-
-if [ -z "$USE_CLANG" ]; then
-  # gcc
-  CC="$GCC_BASE/bin/gcc"
-  CXX="$GCC_BASE/bin/g++"
-
-  CFLAGS+=" -B$BINUTILS/gold"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  JEMALLOC=1
-else
-  # clang
-  CLANG_INCLUDE="$CLANG_LIB/clang/stable/include"
-  CC="$CLANG_BIN/clang"
-  CXX="$CLANG_BIN/clang++"
-
-  KERNEL_HEADERS_INCLUDE="$KERNEL_HEADERS_BASE/include"
-
-  CFLAGS+=" -B$BINUTILS/gold -nostdinc -nostdlib"
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/7.x "
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/7.x/x86_64-facebook-linux "
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $CLANG_INCLUDE"
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE/linux "
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE "
-  CFLAGS+=" -Wno-expansion-to-defined "
-  CXXFLAGS="-nostdinc++"
-fi
-
-CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42"
-CXXFLAGS+=" $CFLAGS"
-
-EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS"
-EXEC_LDFLAGS+=" -B$BINUTILS/gold"
-EXEC_LDFLAGS+=" -Wl,--dynamic-linker,/usr/local/fbcode/platform007/lib/ld.so"
-EXEC_LDFLAGS+=" $LIBUNWIND"
-EXEC_LDFLAGS+=" -Wl,-rpath=/usr/local/fbcode/platform007/lib"
-# required by libtbb
-EXEC_LDFLAGS+=" -ldl"
-
-PLATFORM_LDFLAGS="$LIBGCC_LIBS $GLIBC_LIBS $STDLIBS -lgcc -lstdc++"
-
-EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $TBB_LIBS"
-
-VALGRIND_VER="$VALGRIND_BASE/bin/"
-
-# lua not supported because it's on track for deprecation, I think
-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 LUA_PATH LUA_LIB
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # If clang_format_diff.py command is not specfied, we assume we are able to
 # access directly without any path.
 if [ -z $CLANG_FORMAT_DIFF ]
@@ -1,53 +0,0 @@
-#!/bin/bash
-#  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
-#  This source code is licensed under the BSD-style license found in the
-#  LICENSE file in the root directory of this source tree. An additional grant
-#  of patent rights can be found in the PATENTS file in the same directory.
-
-set -e
-if [ -z "$GIT" ]
-then
-  GIT="git"
-fi
-
-# Print out the colored progress info so that it can be brainlessly
-# distinguished by users.
-function title() {
-  echo -e "\033[1;32m$*\033[0m"
-}
-
-usage="Create new RocksDB version and prepare it for the release process\n"
-usage+="USAGE: ./make_new_version.sh <version> [<remote>]\n"
-usage+="  version: specify a version without '.fb' suffix (e.g. 5.4).\n"
-usage+="  remote: name of the remote to push the branch to (default: origin)."
-
-# -- Pre-check
-if [[ $# < 1 ]]; then
-  echo -e $usage
-  exit 1
-fi
-
-ROCKSDB_VERSION=$1
-
-REMOTE="origin"
-if [[ $# > 1 ]]; then
-  REMOTE=$2
-fi
-
-GIT_BRANCH=`git rev-parse --abbrev-ref HEAD`
-echo $GIT_BRANCH
-
-if [ $GIT_BRANCH != "master" ]; then
-  echo "Error: Current branch is '$GIT_BRANCH', Please switch to master branch."
-  exit 1
-fi
-
-title "Adding new tag for this release ..."
-BRANCH="$ROCKSDB_VERSION.fb"
-$GIT checkout -b $BRANCH
-
-# Setting up the proxy for remote repo access
-title "Pushing new branch to remote repo ..."
-git push $REMOTE --set-upstream $BRANCH
-
-title "Branch $BRANCH is pushed to github;"
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash

 set -e

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # This script is executed by Sandcastle
 # to determine next steps to run

@@ -85,9 +85,8 @@ NON_SHM="TMPD=/tmp/rocksdb_test_tmp"
 GCC_481="ROCKSDB_FBCODE_BUILD_WITH_481=1"
 ASAN="COMPILE_WITH_ASAN=1"
 CLANG="USE_CLANG=1"
-# in gcc-5 there are known problems with TSAN like https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71090.
-# using platform007 gives us gcc-8 or higher which has that bug fixed.
-TSAN="ROCKSDB_FBCODE_BUILD_WITH_PLATFORM007=1 COMPILE_WITH_TSAN=1"
+LITE="OPT=\"-DROCKSDB_LITE -g\""
+TSAN="COMPILE_WITH_TSAN=1"
 UBSAN="COMPILE_WITH_UBSAN=1"
 DISABLE_JEMALLOC="DISABLE_JEMALLOC=1"
 HTTP_PROXY="https_proxy=http://fwdproxy.29.prn1:8080 http_proxy=http://fwdproxy.29.prn1:8080 ftp_proxy=http://fwdproxy.29.prn1:8080"
@@ -565,7 +564,7 @@ TSAN_CRASH_TEST_COMMANDS="[
            {
                'name':'Compile and run',
                'timeout': 86400,
-                'shell':'set -o pipefail && $SHM $DEBUG $TSAN CRASH_TEST_KILL_ODD=1887 make J=1 crash_test || $CONTRUN_NAME=tsan_crash_test $TASK_CREATION_TOOL',
+                'shell':'set -o pipefail && $SHM $DEBUG $TSAN CRASH_TEST_KILL_ODD=1887 CRASH_TEST_EXT_ARGS=--log2_keys_per_lock=22  make J=1 crash_test || $CONTRUN_NAME=tsan_crash_test $TASK_CREATION_TOOL',
                'user':'root',
                $PARSER
            },
@@ -584,39 +583,7 @@ run_format_compatible()
  rm -rf /dev/shm/rocksdb
  mkdir /dev/shm/rocksdb

-  echo '
-  if [ -e "build_tools/build_detect_platform" ]
-  then
-    sed "s/tcmalloc/nothingnothingnothing/g" build_tools/build_detect_platform > $TEST_TMPDIR/temp_build_file
-    rm -rf build_tools/build_detect_platform
-    cp $TEST_TMPDIR/temp_build_file build_tools/build_detect_platform
-    chmod +x build_tools/build_detect_platform
-  fi
-
-  if [ -e "build_detect_platform" ]
-  then
-    sed "s/tcmalloc/nothingnothingnothing/g" build_detect_platform > $TEST_TMPDIR/temp_build_file
-    rm -rf build_detect_platform
-    cp $TEST_TMPDIR/temp_build_file build_detect_platform
-    chmod +x build_detect_platform
-  fi
-
-  make ldb -j32
-
-  if [ -e "build_detect_platform" ]
-  then
-    git checkout -- build_detect_platform
-  fi
-
-  if [ -e "build_tools/build_detect_platform" ]
-  then
-    git checkout -- build_tools/build_detect_platform
-  fi
-  ' > temp_build_ldb.sh
-
-  sed "s/make ldb -j32/source temp_build_ldb.sh/g" tools/check_format_compatible.sh > tools/temp_check_format_compatible.sh
-  chmod +x tools/temp_check_format_compatible.sh
-  tools/temp_check_format_compatible.sh
+  tools/check_format_compatible.sh
 }

 FORMAT_COMPATIBLE_COMMANDS="[
@@ -52,45 +52,6 @@ function get_lib_base()
  log_variable $__res_var
 }

-###########################################################
-#                platform007 dependencies                 #
-###########################################################
-
-OUTPUT="$BASEDIR/dependencies_platform007.sh"
-
-rm -f "$OUTPUT"
-touch "$OUTPUT"
-
-echo "Writing dependencies to $OUTPUT"
-
-# Compilers locations
-GCC_BASE=`readlink -f $TP2_LATEST/gcc/7.x/centos7-native/*/`
-CLANG_BASE=`readlink -f $TP2_LATEST/llvm-fb/stable/centos7-native/*/`
-
-log_variable GCC_BASE
-log_variable CLANG_BASE
-
-# Libraries locations
-get_lib_base libgcc     7.x     platform007
-get_lib_base glibc      2.26    platform007
-get_lib_base snappy     LATEST  platform007
-get_lib_base zlib       LATEST  platform007
-get_lib_base bzip2      LATEST  platform007
-get_lib_base lz4        LATEST  platform007
-get_lib_base zstd       LATEST  platform007
-get_lib_base gflags     LATEST  platform007
-get_lib_base jemalloc   LATEST  platform007
-get_lib_base numa       LATEST  platform007
-get_lib_base libunwind  LATEST  platform007
-get_lib_base tbb        LATEST  platform007
-
-get_lib_base kernel-headers fb platform007
-get_lib_base binutils   LATEST centos7-native
-get_lib_base valgrind   LATEST platform007
-get_lib_base lua        5.3.4  platform007
-
-git diff $OUTPUT
-
 ###########################################################
 #                   5.x dependencies                      #
 ###########################################################
@@ -27,6 +27,11 @@ std::shared_ptr<Cache> NewClockCache(size_t capacity, int num_shard_bits,
 #include <atomic>
 #include <deque>

+// "tbb/concurrent_hash_map.h" requires RTTI if exception is enabled.
+// Disable it so users can chooose to disable RTTI.
+#ifndef ROCKSDB_USE_RTTI
+#define TBB_USE_EXCEPTIONS 0
+#endif
 #include "tbb/concurrent_hash_map.h"

 #include "cache/sharded_cache.h"
@@ -22,7 +22,7 @@

 namespace rocksdb {

-LRUHandleTable::LRUHandleTable() : length_(0), elems_(0), list_(nullptr) {
+LRUHandleTable::LRUHandleTable() : list_(nullptr), length_(0), elems_(0) {
  Resize();
 }

@@ -100,7 +100,7 @@ void LRUHandleTable::Resize() {
 }

 LRUCacheShard::LRUCacheShard()
-    : usage_(0), lru_usage_(0), high_pri_pool_usage_(0) {
+    : high_pri_pool_usage_(0), usage_(0), lru_usage_(0) {
  // Make empty circular linked list
  lru_.next = &lru_;
  lru_.prev = &lru_;
@@ -157,6 +157,16 @@ void LRUCacheShard::TEST_GetLRUList(LRUHandle** lru, LRUHandle** lru_low_pri) {
  *lru_low_pri = lru_low_pri_;
 }

+size_t LRUCacheShard::TEST_GetLRUSize() {
+  LRUHandle* lru_handle = lru_.next;
+  size_t lru_size = 0;
+  while (lru_handle != &lru_) {
+    lru_size++;
+    lru_handle = lru_handle->next;
+  }
+  return lru_size;
+}
+
 void LRUCacheShard::LRU_Remove(LRUHandle* e) {
  assert(e->next != nullptr);
  assert(e->prev != nullptr);
@@ -223,6 +233,22 @@ void LRUCacheShard::EvictFromLRU(size_t charge,
  }
 }

+void* LRUCacheShard::operator new(size_t size) {
+  return port::cacheline_aligned_alloc(size);
+}
+
+void* LRUCacheShard::operator new[](size_t size) {
+  return port::cacheline_aligned_alloc(size);
+}
+
+void LRUCacheShard::operator delete(void *memblock) {
+  port::cacheline_aligned_free(memblock);
+}
+
+void LRUCacheShard::operator delete[](void* memblock) {
+  port::cacheline_aligned_free(memblock);
+}
+
 void LRUCacheShard::SetCapacity(size_t capacity) {
  autovector<LRUHandle*> last_reference_list;
  {
@@ -438,11 +464,18 @@ std::string LRUCacheShard::GetPrintableOptions() const {
 LRUCache::LRUCache(size_t capacity, int num_shard_bits,
                   bool strict_capacity_limit, double high_pri_pool_ratio)
    : ShardedCache(capacity, num_shard_bits, strict_capacity_limit) {
-  int num_shards = 1 << num_shard_bits;
-  shards_ = new LRUCacheShard[num_shards];
+  num_shards_ = 1 << num_shard_bits;
+#if defined(_MSC_VER)
+#pragma warning(push)
+#pragma warning(disable: 4316) // We've validated the alignment with the new operators
+#endif
+  shards_ = new LRUCacheShard[num_shards_];
+#if defined(_MSC_VER)
+#pragma warning(pop)
+#endif
  SetCapacity(capacity);
  SetStrictCapacityLimit(strict_capacity_limit);
-  for (int i = 0; i < num_shards; i++) {
+  for (int i = 0; i < num_shards_; i++) {
    shards_[i].SetHighPriorityPoolRatio(high_pri_pool_ratio);
  }
 }
@@ -469,7 +502,20 @@ uint32_t LRUCache::GetHash(Handle* handle) const {
  return reinterpret_cast<const LRUHandle*>(handle)->hash;
 }

-void LRUCache::DisownData() { shards_ = nullptr; }
+void LRUCache::DisownData() {
+// Do not drop data if compile with ASAN to suppress leak warning.
+#ifndef __SANITIZE_ADDRESS__
+  shards_ = nullptr;
+#endif  // !__SANITIZE_ADDRESS__
+}
+
+size_t LRUCache::TEST_GetLRUSize() {
+  size_t lru_size_of_all_shards = 0;
+  for (int i = 0; i < num_shards_; i++) {
+    lru_size_of_all_shards += shards_[i].TEST_GetLRUSize();
+  }
+  return lru_size_of_all_shards;
+}

 std::shared_ptr<Cache> NewLRUCache(size_t capacity, int num_shard_bits,
                                   bool strict_capacity_limit,
@@ -148,13 +148,13 @@ class LRUHandleTable {

  // The table consists of an array of buckets where each bucket is
  // a linked list of cache entries that hash into the bucket.
+  LRUHandle** list_;
  uint32_t length_;
  uint32_t elems_;
-  LRUHandle** list_;
 };

 // A single shard of sharded cache.
-class LRUCacheShard : public CacheShard {
+class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard : public CacheShard {
 public:
  LRUCacheShard();
  virtual ~LRUCacheShard();
@@ -198,6 +198,19 @@ class LRUCacheShard : public CacheShard {

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

+  //  Retrieves number of elements in LRU, for unit test purpose only
+  //  not threadsafe
+  size_t TEST_GetLRUSize();
+
+  // Overloading to aligned it to cache line size
+  void* operator new(size_t);
+
+  void* operator new[](size_t);
+
+  void operator delete(void *);
+
+  void operator delete[](void*);
+
 private:
  void LRU_Remove(LRUHandle* e);
  void LRU_Insert(LRUHandle* e);
@@ -219,12 +232,6 @@ class LRUCacheShard : public CacheShard {
  // Initialized before use.
  size_t capacity_;

-  // Memory size for entries residing in the cache
-  size_t usage_;
-
-  // Memory size for entries residing only in the LRU list
-  size_t lru_usage_;
-
  // Memory size for entries in high-pri pool.
  size_t high_pri_pool_usage_;

@@ -238,11 +245,6 @@ class LRUCacheShard : public CacheShard {
  // Remember the value to avoid recomputing each time.
  double high_pri_pool_capacity_;

-  // mutex_ protects the following state.
-  // We don't count mutex_ as the cache's internal state so semantically we
-  // don't mind mutex_ invoking the non-const actions.
-  mutable port::Mutex mutex_;
-
  // Dummy head of LRU list.
  // lru.prev is newest entry, lru.next is oldest entry.
  // LRU contains items which can be evicted, ie reference only by cache
@@ -251,7 +253,29 @@ class LRUCacheShard : public CacheShard {
  // Pointer to head of low-pri pool in LRU list.
  LRUHandle* lru_low_pri_;

+  // ------------^^^^^^^^^^^^^-----------
+  // Not frequently modified data members
+  // ------------------------------------
+  //
+  // We separate data members that are updated frequently from the ones that
+  // are not frequently updated so that they don't share the same cache line
+  // which will lead into false cache sharing
+  //
+  // ------------------------------------
+  // Frequently modified data members
+  // ------------vvvvvvvvvvvvv-----------
  LRUHandleTable table_;
+
+  // Memory size for entries residing in the cache
+  size_t usage_;
+
+  // Memory size for entries residing only in the LRU list
+  size_t lru_usage_;
+
+  // mutex_ protects the following state.
+  // We don't count mutex_ as the cache's internal state so semantically we
+  // don't mind mutex_ invoking the non-const actions.
+  mutable port::Mutex mutex_;
 };

 class LRUCache : public ShardedCache {
@@ -267,8 +291,12 @@ class LRUCache : public ShardedCache {
  virtual uint32_t GetHash(Handle* handle) const override;
  virtual void DisownData() override;

+  //  Retrieves number of elements in LRU, for unit test purpose only
+  size_t TEST_GetLRUSize();
+
 private:
  LRUCacheShard* shards_;
+  int num_shards_ = 0;
 };

 }  // namespace rocksdb
@@ -17,7 +17,16 @@ class LRUCacheTest : public testing::Test {
  ~LRUCacheTest() {}

  void NewCache(size_t capacity, double high_pri_pool_ratio = 0.0) {
-    cache_.reset(new LRUCacheShard());
+    cache_.reset(
+#if defined(_MSC_VER)
+#pragma warning(push)
+#pragma warning(disable: 4316) // We've validated the alignment with the new operators
+#endif
+      new LRUCacheShard()
+#if defined(_MSC_VER)
+#pragma warning(pop)
+#endif
+    );
    cache_->SetCapacity(capacity);
    cache_->SetStrictCapacityLimit(false);
    cache_->SetHighPriorityPoolRatio(high_pri_pool_ratio);
@@ -0,0 +1,3 @@
+@PACKAGE_INIT@
+include("${CMAKE_CURRENT_LIST_DIR}/RocksDBTargets.cmake")
+check_required_components(RocksDB)
@@ -0,0 +1,21 @@
+# - Find Bzip2
+# Find the bzip2 compression library and includes
+#
+# BZIP2_INCLUDE_DIR - where to find bzlib.h, etc.
+# BZIP2_LIBRARIES - List of libraries when using bzip2.
+# BZIP2_FOUND - True if bzip2 found.
+
+find_path(BZIP2_INCLUDE_DIR
+  NAMES bzlib.h
+  HINTS ${BZIP2_ROOT_DIR}/include)
+
+find_library(BZIP2_LIBRARIES
+  NAMES bz2
+  HINTS ${BZIP2_ROOT_DIR}/lib)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(bzip2 DEFAULT_MSG BZIP2_LIBRARIES BZIP2_INCLUDE_DIR)
+
+mark_as_advanced(
+  BZIP2_LIBRARIES
+  BZIP2_INCLUDE_DIR)
@@ -0,0 +1,21 @@
+# - Find Lz4
+# Find the lz4 compression library and includes
+#
+# LZ4_INCLUDE_DIR - where to find lz4.h, etc.
+# LZ4_LIBRARIES - List of libraries when using lz4.
+# LZ4_FOUND - True if lz4 found.
+
+find_path(LZ4_INCLUDE_DIR
+  NAMES lz4.h
+  HINTS ${LZ4_ROOT_DIR}/include)
+
+find_library(LZ4_LIBRARIES
+  NAMES lz4
+  HINTS ${LZ4_ROOT_DIR}/lib)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(lz4 DEFAULT_MSG LZ4_LIBRARIES LZ4_INCLUDE_DIR)
+
+mark_as_advanced(
+  LZ4_LIBRARIES
+  LZ4_INCLUDE_DIR)
@@ -0,0 +1,21 @@
+# - Find zlib
+# Find the zlib compression library and includes
+#
+# ZLIB_INCLUDE_DIR - where to find zlib.h, etc.
+# ZLIB_LIBRARIES - List of libraries when using zlib.
+# ZLIB_FOUND - True if zlib found.
+
+find_path(ZLIB_INCLUDE_DIR
+  NAMES zlib.h
+  HINTS ${ZLIB_ROOT_DIR}/include)
+
+find_library(ZLIB_LIBRARIES
+  NAMES z
+  HINTS ${ZLIB_ROOT_DIR}/lib)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(zlib DEFAULT_MSG ZLIB_LIBRARIES ZLIB_INCLUDE_DIR)
+
+mark_as_advanced(
+  ZLIB_LIBRARIES
+  ZLIB_INCLUDE_DIR)
@@ -0,0 +1,21 @@
+# - Find zstd
+# Find the zstd compression library and includes
+#
+# ZSTD_INCLUDE_DIR - where to find zstd.h, etc.
+# ZSTD_LIBRARIES - List of libraries when using zstd.
+# ZSTD_FOUND - True if zstd found.
+
+find_path(ZSTD_INCLUDE_DIR
+  NAMES zstd.h
+  HINTS ${ZSTD_ROOT_DIR}/include)
+
+find_library(ZSTD_LIBRARIES
+  NAMES zstd
+  HINTS ${ZSTD_ROOT_DIR}/lib)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(zstd DEFAULT_MSG ZSTD_LIBRARIES ZSTD_INCLUDE_DIR)
+
+mark_as_advanced(
+  ZSTD_LIBRARIES
+  ZSTD_INCLUDE_DIR)
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash

 # Exit on error.
 set -e
@@ -36,6 +36,7 @@
 #include "utilities/merge_operators.h"
 #include "rocksdb/utilities/transaction.h"
 #include "rocksdb/utilities/transaction_db.h"
+#include "rocksdb/utilities/optimistic_transaction_db.h"
 #include "rocksdb/utilities/checkpoint.h"

 using rocksdb::BytewiseComparator;
@@ -52,6 +53,7 @@ using rocksdb::CompressionType;
 using rocksdb::WALRecoveryMode;
 using rocksdb::DB;
 using rocksdb::DBOptions;
+using rocksdb::DbPath;
 using rocksdb::Env;
 using rocksdb::EnvOptions;
 using rocksdb::InfoLogLevel;
@@ -94,6 +96,8 @@ using rocksdb::PinnableSlice;
 using rocksdb::TransactionDBOptions;
 using rocksdb::TransactionDB;
 using rocksdb::TransactionOptions;
+using rocksdb::OptimisticTransactionDB;
+using rocksdb::OptimisticTransactionOptions;
 using rocksdb::Transaction;
 using rocksdb::Checkpoint;

@@ -152,6 +156,12 @@ struct rocksdb_transaction_t {
 struct rocksdb_checkpoint_t {
  Checkpoint* rep;
 };
+struct rocksdb_optimistictransactiondb_t {
+  OptimisticTransactionDB* rep;
+};
+struct rocksdb_optimistictransaction_options_t {
+  OptimisticTransactionOptions rep;
+};

 struct rocksdb_compactionfiltercontext_t {
  CompactionFilter::Context rep;
@@ -382,6 +392,10 @@ struct rocksdb_mergeoperator_t : public MergeOperator {
  }
 };

+struct rocksdb_dbpath_t {
+  DbPath rep;
+};
+
 struct rocksdb_env_t {
  Env* rep;
  bool is_default;
@@ -1372,24 +1386,23 @@ void rocksdb_writebatch_put_log_data(
  b->rep.PutLogData(Slice(blob, len));
 }

-class H : public WriteBatch::Handler {
- public:
-  void* state_;
-  void (*put_)(void*, const char* k, size_t klen, const char* v, size_t vlen);
-  void (*deleted_)(void*, const char* k, size_t klen);
-  virtual void Put(const Slice& key, const Slice& value) override {
-    (*put_)(state_, key.data(), key.size(), value.data(), value.size());
-  }
-  virtual void Delete(const Slice& key) override {
-    (*deleted_)(state_, key.data(), key.size());
-  }
-};
-
 void rocksdb_writebatch_iterate(
    rocksdb_writebatch_t* b,
    void* state,
    void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
    void (*deleted)(void*, const char* k, size_t klen)) {
+  class H : public WriteBatch::Handler {
+   public:
+    void* state_;
+    void (*put_)(void*, const char* k, size_t klen, const char* v, size_t vlen);
+    void (*deleted_)(void*, const char* k, size_t klen);
+    virtual void Put(const Slice& key, const Slice& value) override {
+      (*put_)(state_, key.data(), key.size(), value.data(), value.size());
+    }
+    virtual void Delete(const Slice& key) override {
+      (*deleted_)(state_, key.data(), key.size());
+    }
+  };
  H handler;
  handler.state_ = state;
  handler.put_ = put;
@@ -1634,6 +1647,18 @@ void rocksdb_writebatch_wi_iterate(
    void* state,
    void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
    void (*deleted)(void*, const char* k, size_t klen)) {
+  class H : public WriteBatch::Handler {
+   public:
+    void* state_;
+    void (*put_)(void*, const char* k, size_t klen, const char* v, size_t vlen);
+    void (*deleted_)(void*, const char* k, size_t klen);
+    virtual void Put(const Slice& key, const Slice& value) override {
+      (*put_)(state_, key.data(), key.size(), value.data(), value.size());
+    }
+    virtual void Delete(const Slice& key) override {
+      (*deleted_)(state_, key.data(), key.size());
+    }
+  };
  H handler;
  handler.state_ = state;
  handler.put_ = put;
@@ -1998,6 +2023,16 @@ void rocksdb_options_set_paranoid_checks(
  opt->rep.paranoid_checks = v;
 }

+void rocksdb_options_set_db_paths(rocksdb_options_t* opt, 
+                                  const rocksdb_dbpath_t** dbpath_values, 
+                                  size_t num_paths) {
+  std::vector<DbPath> db_paths(num_paths);
+  for (size_t i = 0; i < num_paths; ++i) {
+    db_paths[i] = dbpath_values[i]->rep;
+  }
+  opt->rep.db_paths = db_paths;
+}
+
 void rocksdb_options_set_env(rocksdb_options_t* opt, rocksdb_env_t* env) {
  opt->rep.env = (env ? env->rep : nullptr);
 }
@@ -2076,6 +2111,10 @@ void rocksdb_options_enable_statistics(rocksdb_options_t* opt) {
  opt->rep.statistics = rocksdb::CreateDBStatistics();
 }

+void rocksdb_options_set_skip_stats_update_on_db_open(rocksdb_options_t* opt, unsigned char val) {
+  opt->rep.skip_stats_update_on_db_open = val;
+}
+
 void rocksdb_options_set_num_levels(rocksdb_options_t* opt, int n) {
  opt->rep.num_levels = n;
 }
@@ -2778,6 +2817,17 @@ size_t rocksdb_cache_get_pinned_usage(rocksdb_cache_t* cache) {
  return cache->rep->GetPinnedUsage();
 }

+rocksdb_dbpath_t* rocksdb_dbpath_create(const char* path, uint64_t target_size) {
+  rocksdb_dbpath_t* result = new rocksdb_dbpath_t;
+  result->rep.path = std::string(path);
+  result->rep.target_size = target_size;
+  return result;
+}
+
+void rocksdb_dbpath_destroy(rocksdb_dbpath_t* dbpath) {
+  delete dbpath;
+}
+
 rocksdb_env_t* rocksdb_create_default_env() {
  rocksdb_env_t* result = new rocksdb_env_t;
  result->rep = Env::Default();
@@ -2955,21 +3005,20 @@ void rocksdb_slicetransform_destroy(rocksdb_slicetransform_t* st) {
  delete st;
 }

-struct Wrapper : public rocksdb_slicetransform_t {
-  const SliceTransform* rep_;
-  ~Wrapper() { delete rep_; }
-  const char* Name() const override { return rep_->Name(); }
-  Slice Transform(const Slice& src) const override {
-    return rep_->Transform(src);
-  }
-  bool InDomain(const Slice& src) const override {
-    return rep_->InDomain(src);
-  }
-  bool InRange(const Slice& src) const override { return rep_->InRange(src); }
-  static void DoNothing(void*) { }
-};
-
 rocksdb_slicetransform_t* rocksdb_slicetransform_create_fixed_prefix(size_t prefixLen) {
+  struct Wrapper : public rocksdb_slicetransform_t {
+    const SliceTransform* rep_;
+    ~Wrapper() { delete rep_; }
+    const char* Name() const override { return rep_->Name(); }
+    Slice Transform(const Slice& src) const override {
+      return rep_->Transform(src);
+    }
+    bool InDomain(const Slice& src) const override {
+      return rep_->InDomain(src);
+    }
+    bool InRange(const Slice& src) const override { return rep_->InRange(src); }
+    static void DoNothing(void*) { }
+  };
  Wrapper* wrapper = new Wrapper;
  wrapper->rep_ = rocksdb::NewFixedPrefixTransform(prefixLen);
  wrapper->state_ = nullptr;
@@ -2978,6 +3027,19 @@ rocksdb_slicetransform_t* rocksdb_slicetransform_create_fixed_prefix(size_t pref
 }

 rocksdb_slicetransform_t* rocksdb_slicetransform_create_noop() {
+  struct Wrapper : public rocksdb_slicetransform_t {
+    const SliceTransform* rep_;
+    ~Wrapper() { delete rep_; }
+    const char* Name() const override { return rep_->Name(); }
+    Slice Transform(const Slice& src) const override {
+      return rep_->Transform(src);
+    }
+    bool InDomain(const Slice& src) const override {
+      return rep_->InDomain(src);
+    }
+    bool InRange(const Slice& src) const override { return rep_->InRange(src); }
+    static void DoNothing(void*) { }
+  };
  Wrapper* wrapper = new Wrapper;
  wrapper->rep_ = rocksdb::NewNoopTransform();
  wrapper->state_ = nullptr;
@@ -3200,6 +3262,32 @@ void rocksdb_transaction_options_set_max_write_batch_size(
  opt->rep.max_write_batch_size = size;
 }

+rocksdb_optimistictransaction_options_t*
+rocksdb_optimistictransaction_options_create() {
+  return new rocksdb_optimistictransaction_options_t;
+}
+
+void rocksdb_optimistictransaction_options_destroy(
+    rocksdb_optimistictransaction_options_t* opt) {
+  delete opt;
+}
+
+void rocksdb_optimistictransaction_options_set_set_snapshot(
+    rocksdb_optimistictransaction_options_t* opt, unsigned char v) {
+  opt->rep.set_snapshot = v;
+}
+
+rocksdb_column_family_handle_t* rocksdb_transactiondb_create_column_family(
+    rocksdb_transactiondb_t* txn_db,
+    const rocksdb_options_t* column_family_options,
+    const char* column_family_name, char** errptr) {
+  rocksdb_column_family_handle_t* handle = new rocksdb_column_family_handle_t;
+  SaveError(errptr, txn_db->rep->CreateColumnFamily(
+                        ColumnFamilyOptions(column_family_options->rep),
+                        std::string(column_family_name), &(handle->rep)));
+  return handle;
+}
+
 rocksdb_transactiondb_t* rocksdb_transactiondb_open(
    const rocksdb_options_t* options,
    const rocksdb_transactiondb_options_t* txn_db_options, const char* name,
@@ -3256,7 +3344,14 @@ void rocksdb_transaction_destroy(rocksdb_transaction_t* txn) {
  delete txn;
 }

-//Read a key inside a transaction
+const rocksdb_snapshot_t* rocksdb_transaction_get_snapshot(
+    rocksdb_transaction_t* txn) {
+  rocksdb_snapshot_t* result = new rocksdb_snapshot_t;
+  result->rep = txn->rep->GetSnapshot();
+  return result;
+}
+
+// Read a key inside a transaction
 char* rocksdb_transaction_get(rocksdb_transaction_t* txn,
                              const rocksdb_readoptions_t* options,
                              const char* key, size_t klen, size_t* vlen,
@@ -3276,6 +3371,49 @@ char* rocksdb_transaction_get(rocksdb_transaction_t* txn,
  return result;
 }

+char* rocksdb_transaction_get_cf(rocksdb_transaction_t* txn,
+                                 const rocksdb_readoptions_t* options,
+                                 rocksdb_column_family_handle_t* column_family,
+                                 const char* key, size_t klen, size_t* vlen,
+                                 char** errptr) {
+  char* result = nullptr;
+  std::string tmp;
+  Status s =
+      txn->rep->Get(options->rep, column_family->rep, Slice(key, klen), &tmp);
+  if (s.ok()) {
+    *vlen = tmp.size();
+    result = CopyString(tmp);
+  } else {
+    *vlen = 0;
+    if (!s.IsNotFound()) {
+      SaveError(errptr, s);
+    }
+  }
+  return result;
+}
+
+// Read a key inside a transaction
+char* rocksdb_transaction_get_for_update(rocksdb_transaction_t* txn,
+                                         const rocksdb_readoptions_t* options,
+                                         const char* key, size_t klen,
+                                         size_t* vlen, unsigned char exclusive,
+                                         char** errptr) {
+  char* result = nullptr;
+  std::string tmp;
+  Status s =
+      txn->rep->GetForUpdate(options->rep, Slice(key, klen), &tmp, exclusive);
+  if (s.ok()) {
+    *vlen = tmp.size();
+    result = CopyString(tmp);
+  } else {
+    *vlen = 0;
+    if (!s.IsNotFound()) {
+      SaveError(errptr, s);
+    }
+  }
+  return result;
+}
+
 // Read a key outside a transaction
 char* rocksdb_transactiondb_get(
    rocksdb_transactiondb_t* txn_db,
@@ -3298,6 +3436,26 @@ char* rocksdb_transactiondb_get(
  return result;
 }

+char* rocksdb_transactiondb_get_cf(
+    rocksdb_transactiondb_t* txn_db, const rocksdb_readoptions_t* options,
+    rocksdb_column_family_handle_t* column_family, const char* key,
+    size_t keylen, size_t* vallen, char** errptr) {
+  char* result = nullptr;
+  std::string tmp;
+  Status s = txn_db->rep->Get(options->rep, column_family->rep,
+                              Slice(key, keylen), &tmp);
+  if (s.ok()) {
+    *vallen = tmp.size();
+    result = CopyString(tmp);
+  } else {
+    *vallen = 0;
+    if (!s.IsNotFound()) {
+      SaveError(errptr, s);
+    }
+  }
+  return result;
+}
+
 // Put a key inside a transaction
 void rocksdb_transaction_put(rocksdb_transaction_t* txn, const char* key,
                             size_t klen, const char* val, size_t vlen,
@@ -3305,13 +3463,56 @@ void rocksdb_transaction_put(rocksdb_transaction_t* txn, const char* key,
  SaveError(errptr, txn->rep->Put(Slice(key, klen), Slice(val, vlen)));
 }

-//Put a key outside a transaction
+void rocksdb_transaction_put_cf(rocksdb_transaction_t* txn,
+                                rocksdb_column_family_handle_t* column_family,
+                                const char* key, size_t klen, const char* val,
+                                size_t vlen, char** errptr) {
+  SaveError(errptr, txn->rep->Put(column_family->rep, Slice(key, klen),
+                                  Slice(val, vlen)));
+}
+
+// Put a key outside a transaction
 void rocksdb_transactiondb_put(rocksdb_transactiondb_t* txn_db,
                               const rocksdb_writeoptions_t* options,
                               const char* key, size_t klen, const char* val,
                               size_t vlen, char** errptr) {
+  SaveError(errptr, txn_db->rep->Put(options->rep, Slice(key, klen), 
+                                     Slice(val, vlen)));
+}
+
+void rocksdb_transactiondb_put_cf(rocksdb_transactiondb_t* txn_db,
+                                  const rocksdb_writeoptions_t* options,
+                                  rocksdb_column_family_handle_t* column_family,
+                                  const char* key, size_t keylen,
+                                  const char* val, size_t vallen,
+                                  char** errptr) {
+  SaveError(errptr, txn_db->rep->Put(options->rep, column_family->rep,
+                                     Slice(key, keylen), Slice(val, vallen)));
+}
+
+// Write batch into transaction db
+void rocksdb_transactiondb_write(
+        rocksdb_transactiondb_t* db,
+        const rocksdb_writeoptions_t* options,
+        rocksdb_writebatch_t* batch,
+        char** errptr) {
+  SaveError(errptr, db->rep->Write(options->rep, &batch->rep));
+}
+
+// Merge a key inside a transaction
+void rocksdb_transaction_merge(rocksdb_transaction_t* txn, const char* key,
+                               size_t klen, const char* val, size_t vlen,
+                               char** errptr) {
+  SaveError(errptr, txn->rep->Merge(Slice(key, klen), Slice(val, vlen)));
+}
+
+// Merge a key outside a transaction
+void rocksdb_transactiondb_merge(rocksdb_transactiondb_t* txn_db,
+                                 const rocksdb_writeoptions_t* options,
+                                 const char* key, size_t klen, const char* val,
+                                 size_t vlen, char** errptr) {
  SaveError(errptr,
-            txn_db->rep->Put(options->rep, Slice(key, klen), Slice(val, vlen)));
+    txn_db->rep->Merge(options->rep, Slice(key, klen), Slice(val, vlen)));
 }

 // Delete a key inside a transaction
@@ -3320,6 +3521,12 @@ void rocksdb_transaction_delete(rocksdb_transaction_t* txn, const char* key,
  SaveError(errptr, txn->rep->Delete(Slice(key, klen)));
 }

+void rocksdb_transaction_delete_cf(
+    rocksdb_transaction_t* txn, rocksdb_column_family_handle_t* column_family,
+    const char* key, size_t klen, char** errptr) {
+  SaveError(errptr, txn->rep->Delete(column_family->rep, Slice(key, klen)));
+}
+
 // Delete a key outside a transaction
 void rocksdb_transactiondb_delete(rocksdb_transactiondb_t* txn_db,
                                  const rocksdb_writeoptions_t* options,
@@ -3327,6 +3534,14 @@ void rocksdb_transactiondb_delete(rocksdb_transactiondb_t* txn_db,
  SaveError(errptr, txn_db->rep->Delete(options->rep, Slice(key, klen)));
 }

+void rocksdb_transactiondb_delete_cf(
+    rocksdb_transactiondb_t* txn_db, const rocksdb_writeoptions_t* options,
+    rocksdb_column_family_handle_t* column_family, const char* key,
+    size_t keylen, char** errptr) {
+  SaveError(errptr, txn_db->rep->Delete(options->rep, column_family->rep,
+                                        Slice(key, keylen)));
+}
+
 // Create an iterator inside a transaction
 rocksdb_iterator_t* rocksdb_transaction_create_iterator(
    rocksdb_transaction_t* txn, const rocksdb_readoptions_t* options) {
@@ -3335,6 +3550,14 @@ rocksdb_iterator_t* rocksdb_transaction_create_iterator(
  return result;
 }

+// Create an iterator outside a transaction
+rocksdb_iterator_t* rocksdb_transactiondb_create_iterator(
+    rocksdb_transactiondb_t* txn_db, const rocksdb_readoptions_t* options) {
+  rocksdb_iterator_t* result = new rocksdb_iterator_t;
+  result->rep = txn_db->rep->NewIterator(options->rep);
+  return result;
+}
+
 void rocksdb_transactiondb_close(rocksdb_transactiondb_t* txn_db) {
  delete txn_db->rep;
  delete txn_db;
@@ -3351,6 +3574,42 @@ rocksdb_checkpoint_t* rocksdb_transactiondb_checkpoint_object_create(
  return result;
 }

+rocksdb_optimistictransactiondb_t* rocksdb_optimistictransactiondb_open(
+    const rocksdb_options_t* options, const char* name,
+    char** errptr) {
+  OptimisticTransactionDB* otxn_db;
+  if (SaveError(errptr, OptimisticTransactionDB::Open(
+                            options->rep, std::string(name), &otxn_db))) {
+    return nullptr;
+  }
+  rocksdb_optimistictransactiondb_t* result =
+      new rocksdb_optimistictransactiondb_t;
+  result->rep = otxn_db;
+  return result;
+}
+
+rocksdb_transaction_t* rocksdb_optimistictransaction_begin(
+    rocksdb_optimistictransactiondb_t* otxn_db,
+    const rocksdb_writeoptions_t* write_options,
+    const rocksdb_optimistictransaction_options_t* otxn_options,
+    rocksdb_transaction_t* old_txn) {
+  if (old_txn == nullptr) {
+    rocksdb_transaction_t* result = new rocksdb_transaction_t;
+    result->rep = otxn_db->rep->BeginTransaction(write_options->rep,
+                                                 otxn_options->rep, nullptr);
+    return result;
+  }
+  old_txn->rep = otxn_db->rep->BeginTransaction(
+      write_options->rep, otxn_options->rep, old_txn->rep);
+  return old_txn;
+}
+
+void rocksdb_optimistictransactiondb_close(
+    rocksdb_optimistictransactiondb_t* otxn_db) {
+  delete otxn_db->rep;
+  delete otxn_db;
+}
+
 void rocksdb_free(void* ptr) { free(ptr); }

 rocksdb_pinnableslice_t* rocksdb_get_pinned(
@@ -41,6 +41,7 @@ static char dbname[200];
 static char sstfilename[200];
 static char dbbackupname[200];
 static char dbcheckpointname[200];
+static char dbpathname[200];

 static void StartPhase(const char* name) {
  fprintf(stderr, "=== Test %s\n", name);
@@ -347,10 +348,25 @@ static void CheckTxnDBGet(
        Free(&val);
 }

+static void CheckTxnDBGetCF(rocksdb_transactiondb_t* txn_db,
+                            const rocksdb_readoptions_t* options,
+                            rocksdb_column_family_handle_t* column_family,
+                            const char* key, const char* expected) {
+  char* err = NULL;
+  size_t val_len;
+  char* val;
+  val = rocksdb_transactiondb_get_cf(txn_db, options, column_family, key,
+                                     strlen(key), &val_len, &err);
+  CheckNoError(err);
+  CheckEqual(expected, val, val_len);
+  Free(&val);
+}
+
 int main(int argc, char** argv) {
  rocksdb_t* db;
  rocksdb_comparator_t* cmp;
  rocksdb_cache_t* cache;
+  rocksdb_dbpath_t *dbpath;
  rocksdb_env_t* env;
  rocksdb_options_t* options;
  rocksdb_compactoptions_t* coptions;
@@ -385,8 +401,14 @@ int main(int argc, char** argv) {
           GetTempDir(),
           ((int)geteuid()));

+  snprintf(dbpathname, sizeof(dbpathname),
+           "%s/rocksdb_c_test-%d-dbpath",
+           GetTempDir(),
+           ((int) geteuid()));
+
  StartPhase("create_objects");
  cmp = rocksdb_comparator_create(NULL, CmpDestroy, CmpCompare, CmpName);
+  dbpath = rocksdb_dbpath_create(dbpathname, 1024 * 1024);
  env = rocksdb_create_default_env();
  cache = rocksdb_cache_create_lru(100000);

@@ -1357,6 +1379,18 @@ int main(int argc, char** argv) {
    CheckNoError(err);
    CheckTxnDBGet(txn_db, roptions, "foo", NULL);

+    // write batch into TransactionDB
+    rocksdb_writebatch_t* wb = rocksdb_writebatch_create();
+    rocksdb_writebatch_put(wb, "foo", 3, "a", 1);
+    rocksdb_writebatch_clear(wb);
+    rocksdb_writebatch_put(wb, "bar", 3, "b", 1);
+    rocksdb_writebatch_put(wb, "box", 3, "c", 1);
+    rocksdb_writebatch_delete(wb, "bar", 3);
+    rocksdb_transactiondb_write(txn_db, woptions, wb, &err);
+    rocksdb_writebatch_destroy(wb);
+    CheckTxnDBGet(txn_db, roptions, "box", "c");
+    CheckNoError(err);
+
    // begin a transaction
    txn = rocksdb_transaction_begin(txn_db, woptions, txn_options, NULL);
    // put
@@ -1413,6 +1447,23 @@ int main(int argc, char** argv) {
    CheckNoError(err);
    CheckTxnDBGet(txn_db, roptions, "bar", NULL);

+    // Column families.
+    rocksdb_column_family_handle_t* cfh;
+    cfh = rocksdb_transactiondb_create_column_family(txn_db, options,
+                                                     "txn_db_cf", &err);
+    CheckNoError(err);
+
+    rocksdb_transactiondb_put_cf(txn_db, woptions, cfh, "cf_foo", 6, "cf_hello",
+                                 8, &err);
+    CheckNoError(err);
+    CheckTxnDBGetCF(txn_db, roptions, cfh, "cf_foo", "cf_hello");
+
+    rocksdb_transactiondb_delete_cf(txn_db, woptions, cfh, "cf_foo", 6, &err);
+    CheckNoError(err);
+    CheckTxnDBGetCF(txn_db, roptions, cfh, "cf_foo", NULL);
+
+    rocksdb_column_family_handle_destroy(cfh);
+
    // close and destroy
    rocksdb_transaction_destroy(txn);
    rocksdb_transactiondb_close(txn_db);
@@ -1440,6 +1491,18 @@ int main(int argc, char** argv) {
    CheckNoError(err);
  }

+  // Simple sanity check that options setting db_paths work.
+  StartPhase("open_db_paths");
+  {
+    rocksdb_close(db);
+    rocksdb_destroy_db(options, dbname, &err);
+
+    const rocksdb_dbpath_t* paths[1] = {dbpath};
+    rocksdb_options_set_db_paths(options, paths, 1);
+    db = rocksdb_open(options, dbname, &err);
+    CheckNoError(err);
+  }
+  
  StartPhase("cleanup");
  rocksdb_close(db);
  rocksdb_options_destroy(options);
@@ -1449,6 +1512,7 @@ int main(int argc, char** argv) {
  rocksdb_compactoptions_destroy(coptions);
  rocksdb_cache_destroy(cache);
  rocksdb_comparator_destroy(cmp);
+  rocksdb_dbpath_destroy(dbpath);
  rocksdb_env_destroy(env);

  fprintf(stderr, "PASS\n");
@@ -521,6 +521,7 @@ TEST_F(ColumnFamilyTest, DontReuseColumnFamilyID) {
  }
 }

+#ifndef ROCKSDB_LITE
 TEST_F(ColumnFamilyTest, CreateCFRaceWithGetAggProperty) {
  Open();

@@ -542,6 +543,7 @@ TEST_F(ColumnFamilyTest, CreateCFRaceWithGetAggProperty) {

  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
 }
+#endif  // !ROCKSDB_LITE

 class FlushEmptyCFTestWithParam : public ColumnFamilyTest,
                                  public testing::WithParamInterface<bool> {
@@ -169,6 +169,7 @@ Compaction::Compaction(VersionStorageInfo* vstorage,
      bottommost_level_(IsBottommostLevel(output_level_, vstorage, inputs_)),
      is_full_compaction_(IsFullCompaction(vstorage, inputs_)),
      is_manual_compaction_(_manual_compaction),
+      is_trivial_move_(false),
      compaction_reason_(_compaction_reason) {
  MarkFilesBeingCompacted(true);
  if (is_manual_compaction_) {
@@ -16,6 +16,8 @@ struct CompactionIterationStats {
  int64_t num_record_drop_obsolete = 0;
  int64_t num_record_drop_range_del = 0;
  int64_t num_range_del_drop_obsolete = 0;
+  // Deletions obsoleted before bottom level due to file gap optimization.
+  int64_t num_optimized_del_drop_obsolete = 0;
  uint64_t total_filter_time = 0;

  // Input statistics
@@ -111,6 +111,7 @@ void CompactionIterator::ResetRecordCounts() {
  iter_stats_.num_record_drop_obsolete = 0;
  iter_stats_.num_record_drop_range_del = 0;
  iter_stats_.num_range_del_drop_obsolete = 0;
+  iter_stats_.num_optimized_del_drop_obsolete = 0;
 }

 void CompactionIterator::SeekToFirst() {
@@ -426,6 +427,9 @@ void CompactionIterator::NextFromInput() {
          // Can compact out this SingleDelete.
          ++iter_stats_.num_record_drop_obsolete;
          ++iter_stats_.num_single_del_fallthru;
+          if (!bottommost_level_) {
+            ++iter_stats_.num_optimized_del_drop_obsolete;
+          }
        } else {
          // Output SingleDelete
          valid_ = true;
@@ -467,6 +471,9 @@ void CompactionIterator::NextFromInput() {
      // Note:  Dropping this Delete will not affect TransactionDB
      // write-conflict checking since it is earlier than any snapshot.
      ++iter_stats_.num_record_drop_obsolete;
+      if (!bottommost_level_) {
+        ++iter_stats_.num_optimized_del_drop_obsolete;
+      }
      input_->Next();
    } else if (ikey_.type == kTypeMerge) {
      if (!merge_helper_->HasOperator()) {
@@ -455,6 +455,111 @@ TEST_F(CompactionIteratorTest, ShuttingDownInMerge) {
  EXPECT_EQ(2, filter.last_seen.load());
 }

+TEST_F(CompactionIteratorTest, SingleMergeOperand) {
+  class Filter : public CompactionFilter {
+    virtual Decision FilterV2(int level, const Slice& key, ValueType t,
+                              const Slice& existing_value,
+                              std::string* new_value,
+                              std::string* skip_until) const override {
+      std::string k = key.ToString();
+      std::string v = existing_value.ToString();
+
+      // See InitIterators() call below for the sequence of keys and their
+      // filtering decisions. Here we closely assert that compaction filter is
+      // called with the expected keys and only them, and with the right values.
+      if (k == "a") {
+        EXPECT_EQ(ValueType::kMergeOperand, t);
+        EXPECT_EQ("av1", v);
+        return Decision::kKeep;
+      } else if (k == "b") {
+        EXPECT_EQ(ValueType::kMergeOperand, t);
+        return Decision::kKeep;
+      } else if (k == "c") {
+        return Decision::kKeep;
+      }
+
+      ADD_FAILURE();
+      return Decision::kKeep;
+    }
+
+    const char* Name() const override {
+      return "CompactionIteratorTest.SingleMergeOperand::Filter";
+    }
+  };
+
+  class SingleMergeOp : public MergeOperator {
+   public:
+    bool FullMergeV2(const MergeOperationInput& merge_in,
+                     MergeOperationOutput* merge_out) const override {
+      // See InitIterators() call below for why "c" is the only key for which
+      // FullMergeV2 should be called.
+      EXPECT_EQ("c", merge_in.key.ToString());
+
+      std::string temp_value;
+      if (merge_in.existing_value != nullptr) {
+        temp_value = merge_in.existing_value->ToString();
+      }
+
+      for (auto& operand : merge_in.operand_list) {
+        temp_value.append(operand.ToString());
+      }
+      merge_out->new_value = temp_value;
+
+      return true;
+    }
+
+    bool PartialMergeMulti(const Slice& key,
+                           const std::deque<Slice>& operand_list,
+                           std::string* new_value,
+                           Logger* logger) const override {
+      std::string string_key = key.ToString();
+      EXPECT_TRUE(string_key == "a" || string_key == "b");
+
+      if (string_key == "a") {
+        EXPECT_EQ(1, operand_list.size());
+      } else if (string_key == "b") {
+        EXPECT_EQ(2, operand_list.size());
+      }
+
+      std::string temp_value;
+      for (auto& operand : operand_list) {
+        temp_value.append(operand.ToString());
+      }
+      swap(temp_value, *new_value);
+
+      return true;
+    }
+
+    const char* Name() const override {
+      return "CompactionIteratorTest SingleMergeOp";
+    }
+
+    bool AllowSingleOperand() const override { return true; }
+  };
+
+  SingleMergeOp merge_op;
+  Filter filter;
+  InitIterators(
+      // a should invoke PartialMergeMulti with a single merge operand.
+      {test::KeyStr("a", 50, kTypeMerge),
+       // b should invoke PartialMergeMulti with two operands.
+       test::KeyStr("b", 70, kTypeMerge), test::KeyStr("b", 60, kTypeMerge),
+       // c should invoke FullMerge due to kTypeValue at the beginning.
+       test::KeyStr("c", 90, kTypeMerge), test::KeyStr("c", 80, kTypeValue)},
+      {"av1", "bv2", "bv1", "cv2", "cv1"}, {}, {}, kMaxSequenceNumber,
+      &merge_op, &filter);
+
+  c_iter_->SeekToFirst();
+  ASSERT_TRUE(c_iter_->Valid());
+  ASSERT_EQ(test::KeyStr("a", 50, kTypeMerge), c_iter_->key().ToString());
+  ASSERT_EQ("av1", c_iter_->value().ToString());
+  c_iter_->Next();
+  ASSERT_TRUE(c_iter_->Valid());
+  ASSERT_EQ("bv1bv2", c_iter_->value().ToString());
+  c_iter_->Next();
+  ASSERT_EQ("cv1cv2", c_iter_->value().ToString());
+}
+
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -594,6 +594,9 @@ Status CompactionJob::Install(const MutableCFOptions& mutable_cf_options) {

  double read_write_amp = 0.0;
  double write_amp = 0.0;
+  double bytes_read_per_sec = 0;
+  double bytes_written_per_sec = 0;
+
  if (stats.bytes_read_non_output_levels > 0) {
    read_write_amp = (stats.bytes_written + stats.bytes_read_output_level +
                      stats.bytes_read_non_output_levels) /
@@ -601,17 +604,22 @@ Status CompactionJob::Install(const MutableCFOptions& mutable_cf_options) {
    write_amp = stats.bytes_written /
                static_cast<double>(stats.bytes_read_non_output_levels);
  }
+  if (stats.micros > 0) {
+    bytes_read_per_sec =
+        (stats.bytes_read_non_output_levels + stats.bytes_read_output_level) /
+        static_cast<double>(stats.micros);
+    bytes_written_per_sec =
+        stats.bytes_written / static_cast<double>(stats.micros);
+  }
+
  ROCKS_LOG_BUFFER(
      log_buffer_,
      "[%s] compacted to: %s, MB/sec: %.1f rd, %.1f wr, level %d, "
      "files in(%d, %d) out(%d) "
      "MB in(%.1f, %.1f) out(%.1f), read-write-amplify(%.1f) "
      "write-amplify(%.1f) %s, records in: %d, records dropped: %d\n",
-      cfd->GetName().c_str(), vstorage->LevelSummary(&tmp),
-      (stats.bytes_read_non_output_levels + stats.bytes_read_output_level) /
-          static_cast<double>(stats.micros),
-      stats.bytes_written / static_cast<double>(stats.micros),
-      compact_->compaction->output_level(),
+      cfd->GetName().c_str(), vstorage->LevelSummary(&tmp), bytes_read_per_sec,
+      bytes_written_per_sec, compact_->compaction->output_level(),
      stats.num_input_files_in_non_output_levels,
      stats.num_input_files_in_output_level, stats.num_output_files,
      stats.bytes_read_non_output_levels / 1048576.0,
@@ -1006,6 +1014,10 @@ void CompactionJob::RecordDroppedKeys(
    RecordTick(stats_, COMPACTION_RANGE_DEL_DROP_OBSOLETE,
               c_iter_stats.num_range_del_drop_obsolete);
  }
+  if (c_iter_stats.num_optimized_del_drop_obsolete > 0) {
+    RecordTick(stats_, COMPACTION_OPTIMIZED_DEL_DROP_OBSOLETE,
+               c_iter_stats.num_optimized_del_drop_obsolete);
+  }
 }

 Status CompactionJob::FinishCompactionOutputFile(
@@ -234,11 +234,6 @@ bool CompactionPicker::ExpandInputsToCleanCut(const std::string& cf_name,
  // If, after the expansion, there are files that are already under
  // compaction, then we must drop/cancel this compaction.
  if (AreFilesInCompaction(inputs->files)) {
-    ROCKS_LOG_WARN(
-        ioptions_.info_log,
-        "[%s] ExpandWhileOverlapping() failure because some of the necessary"
-        " compaction input files are currently being compacted.",
-        cf_name.c_str());
    return false;
  }
  return true;
@@ -1106,11 +1101,7 @@ void LevelCompactionBuilder::SetupInitialFiles() {
      }
      output_level_ =
          (start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
-      if (PickFileToCompact() &&
-          compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
-                                                     &start_level_inputs_) &&
-          !compaction_picker_->FilesRangeOverlapWithCompaction(
-              {start_level_inputs_}, output_level_)) {
+      if (PickFileToCompact()) {
        // found the compaction!
        if (start_level_ == 0) {
          // L0 score = `num L0 files` / `level0_file_num_compaction_trigger`
@@ -1332,12 +1323,10 @@ bool LevelCompactionBuilder::PickFileToCompact() {
  const std::vector<FileMetaData*>& level_files =
      vstorage_->LevelFiles(start_level_);

-  // record the first file that is not yet compacted
-  int nextIndex = -1;
-
-  for (unsigned int i = vstorage_->NextCompactionIndex(start_level_);
-       i < file_size.size(); i++) {
-    int index = file_size[i];
+  unsigned int cmp_idx;
+  for (cmp_idx = vstorage_->NextCompactionIndex(start_level_);
+       cmp_idx < file_size.size(); cmp_idx++) {
+    int index = file_size[cmp_idx];
    auto* f = level_files[index];

    // do not pick a file to compact if it is being compacted
@@ -1346,27 +1335,42 @@ bool LevelCompactionBuilder::PickFileToCompact() {
      continue;
    }

-    // remember the startIndex for the next call to PickCompaction
-    if (nextIndex == -1) {
-      nextIndex = i;
-    }
-
-    // Do not pick this file if its parents at level+1 are being compacted.
-    // Maybe we can avoid redoing this work in SetupOtherInputs
-    parent_index_ = -1;
-    if (compaction_picker_->IsRangeInCompaction(vstorage_, &f->smallest,
-                                                &f->largest, output_level_,
-                                                &parent_index_)) {
-      continue;
-    }
    start_level_inputs_.files.push_back(f);
    start_level_inputs_.level = start_level_;
+    if (!compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
+                                                    &start_level_inputs_) ||
+        compaction_picker_->FilesRangeOverlapWithCompaction(
+            {start_level_inputs_}, output_level_)) {
+      // A locked (pending compaction) input-level file was pulled in due to
+      // user-key overlap.
+      start_level_inputs_.clear();
+      continue;
+    }
+
+    // Now that input level is fully expanded, we check whether any output files
+    // are locked due to pending compaction.
+    //
+    // Note we rely on ExpandInputsToCleanCut() to tell us whether any output-
+    // level files are locked, not just the extra ones pulled in for user-key
+    // overlap.
+    InternalKey smallest, largest;
+    compaction_picker_->GetRange(start_level_inputs_, &smallest, &largest);
+    CompactionInputFiles output_level_inputs;
+    output_level_inputs.level = output_level_;
+    vstorage_->GetOverlappingInputs(output_level_, &smallest, &largest,
+                                    &output_level_inputs.files);
+    if (!output_level_inputs.empty() &&
+        !compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
+                                                    &output_level_inputs)) {
+      start_level_inputs_.clear();
+      continue;
+    }
    base_index_ = index;
    break;
  }

  // store where to start the iteration in the next call to PickCompaction
-  vstorage_->SetNextCompactionIndex(start_level_, nextIndex);
+  vstorage_->SetNextCompactionIndex(start_level_, cmp_idx);

  return start_level_inputs_.size() > 0;
 }
@@ -512,7 +512,7 @@ TEST_F(CompactionPickerTest, NeedsCompactionFIFO) {
        kFileSize, 0, i * 100, i * 100 + 99);
    current_size += kFileSize;
    UpdateVersionStorageInfo();
-    ASSERT_EQ(level_compaction_picker.NeedsCompaction(vstorage_.get()),
+    ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()),
              vstorage_->CompactionScore(0) >= 1);
  }
 }
@@ -852,6 +852,80 @@ TEST_F(CompactionPickerTest, OverlappingUserKeys9) {
  ASSERT_EQ(8U, compaction->input(1, 1)->fd.GetNumber());
 }

+TEST_F(CompactionPickerTest, OverlappingUserKeys10) {
+  // Locked file encountered when pulling in extra input-level files with same
+  // user keys. Verify we pick the next-best file from the same input level.
+  NewVersionStorage(6, kCompactionStyleLevel);
+  mutable_cf_options_.max_compaction_bytes = 100000000000u;
+
+  // file_number 2U is largest and thus first choice. But it overlaps with
+  // file_number 1U which is being compacted. So instead we pick the next-
+  // biggest file, 3U, which is eligible for compaction.
+  Add(1 /* level */, 1U /* file_number */, "100" /* smallest */,
+      "150" /* largest */, 1U /* file_size */);
+  file_map_[1U].first->being_compacted = true;
+  Add(1 /* level */, 2U /* file_number */, "150" /* smallest */,
+      "200" /* largest */, 1000000000U /* file_size */, 0 /* smallest_seq */,
+      0 /* largest_seq */);
+  Add(1 /* level */, 3U /* file_number */, "201" /* smallest */,
+      "250" /* largest */, 900000000U /* file_size */);
+  Add(2 /* level */, 4U /* file_number */, "100" /* smallest */,
+      "150" /* largest */, 1U /* file_size */);
+  Add(2 /* level */, 5U /* file_number */, "151" /* smallest */,
+      "200" /* largest */, 1U /* file_size */);
+  Add(2 /* level */, 6U /* file_number */, "201" /* smallest */,
+      "250" /* largest */, 1U /* file_size */);
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(level_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(2U, compaction->num_input_levels());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(1U, compaction->num_input_files(1));
+  ASSERT_EQ(3U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(6U, compaction->input(1, 0)->fd.GetNumber());
+}
+
+TEST_F(CompactionPickerTest, OverlappingUserKeys11) {
+  // Locked file encountered when pulling in extra output-level files with same
+  // user keys. Expected to skip that compaction and pick the next-best choice.
+  NewVersionStorage(6, kCompactionStyleLevel);
+  mutable_cf_options_.max_compaction_bytes = 100000000000u;
+
+  // score(L1) = 3.7
+  // score(L2) = 1.85
+  // There is no eligible file in L1 to compact since both candidates pull in
+  // file_number 5U, which overlaps with a file pending compaction (6U). The
+  // first eligible compaction is from L2->L3.
+  Add(1 /* level */, 2U /* file_number */, "151" /* smallest */,
+      "200" /* largest */, 1000000000U /* file_size */);
+  Add(1 /* level */, 3U /* file_number */, "201" /* smallest */,
+      "250" /* largest */, 1U /* file_size */);
+  Add(2 /* level */, 4U /* file_number */, "100" /* smallest */,
+      "149" /* largest */, 5000000000U /* file_size */);
+  Add(2 /* level */, 5U /* file_number */, "150" /* smallest */,
+      "201" /* largest */, 1U /* file_size */);
+  Add(2 /* level */, 6U /* file_number */, "201" /* smallest */,
+      "249" /* largest */, 1U /* file_size */, 0 /* smallest_seq */,
+      0 /* largest_seq */);
+  file_map_[6U].first->being_compacted = true;
+  Add(3 /* level */, 7U /* file_number */, "100" /* smallest */,
+      "149" /* largest */, 1U /* file_size */);
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(level_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(2U, compaction->num_input_levels());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(1U, compaction->num_input_files(1));
+  ASSERT_EQ(4U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(7U, compaction->input(1, 0)->fd.GetNumber());
+}
+
 TEST_F(CompactionPickerTest, NotScheduleL1IfL0WithHigherPri1) {
  NewVersionStorage(6, kCompactionStyleLevel);
  mutable_cf_options_.level0_file_num_compaction_trigger = 2;
@@ -1316,6 +1390,49 @@ TEST_F(CompactionPickerTest, IsTrivialMoveOff) {
  ASSERT_FALSE(compaction->IsTrivialMove());
 }

+TEST_F(CompactionPickerTest, CacheNextCompactionIndex) {
+  NewVersionStorage(6, kCompactionStyleLevel);
+  mutable_cf_options_.max_compaction_bytes = 100000000000u;
+
+  Add(1 /* level */, 1U /* file_number */, "100" /* smallest */,
+      "149" /* largest */, 1000000000U /* file_size */);
+  file_map_[1U].first->being_compacted = true;
+  Add(1 /* level */, 2U /* file_number */, "150" /* smallest */,
+      "199" /* largest */, 900000000U /* file_size */);
+  Add(1 /* level */, 3U /* file_number */, "200" /* smallest */,
+      "249" /* largest */, 800000000U /* file_size */);
+  Add(1 /* level */, 4U /* file_number */, "250" /* smallest */,
+      "299" /* largest */, 700000000U /* file_size */);
+  Add(2 /* level */, 5U /* file_number */, "150" /* smallest */,
+      "199" /* largest */, 1U /* file_size */);
+  file_map_[5U].first->being_compacted = true;
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(level_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(1U, compaction->num_input_levels());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(0U, compaction->num_input_files(1));
+  ASSERT_EQ(3U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(2, vstorage_->NextCompactionIndex(1 /* level */));
+
+  compaction.reset(level_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_TRUE(compaction.get() != nullptr);
+  ASSERT_EQ(1U, compaction->num_input_levels());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(0U, compaction->num_input_files(1));
+  ASSERT_EQ(4U, compaction->input(0, 0)->fd.GetNumber());
+  ASSERT_EQ(3, vstorage_->NextCompactionIndex(1 /* level */));
+
+  compaction.reset(level_compaction_picker.PickCompaction(
+      cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_TRUE(compaction.get() == nullptr);
+  ASSERT_EQ(4, vstorage_->NextCompactionIndex(1 /* level */));
+}
+
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -373,6 +373,7 @@ Compaction* UniversalCompactionPicker::PickCompaction(
              c->inputs(0)->size());

  RegisterCompaction(c);
+  vstorage->ComputeCompactionScore(ioptions_, mutable_cf_options);

  TEST_SYNC_POINT_CALLBACK("UniversalCompactionPicker::PickCompaction:Return",
                           c);
@@ -9,19 +9,50 @@
 #include "rocksdb/convenience.h"

 #include "db/db_impl.h"
+#include "util/cast_util.h"

 namespace rocksdb {

 void CancelAllBackgroundWork(DB* db, bool wait) {
-  (dynamic_cast<DBImpl*>(db->GetRootDB()))->CancelAllBackgroundWork(wait);
+  (static_cast_with_check<DBImpl, DB>(db->GetRootDB()))
+      ->CancelAllBackgroundWork(wait);
 }

 Status DeleteFilesInRange(DB* db, ColumnFamilyHandle* column_family,
                          const Slice* begin, const Slice* end) {
-  return (dynamic_cast<DBImpl*>(db->GetRootDB()))
+  return (static_cast_with_check<DBImpl, DB>(db->GetRootDB()))
      ->DeleteFilesInRange(column_family, begin, end);
 }

+Status VerifySstFileChecksum(const Options& options,
+                             const EnvOptions& env_options,
+                             const std::string& file_path) {
+  unique_ptr<RandomAccessFile> file;
+  uint64_t file_size;
+  InternalKeyComparator internal_comparator(options.comparator);
+  ImmutableCFOptions ioptions(options);
+
+  Status s = ioptions.env->NewRandomAccessFile(file_path, &file, env_options);
+  if (s.ok()) {
+    s = ioptions.env->GetFileSize(file_path, &file_size);
+  } else {
+    return s;
+  }
+  unique_ptr<TableReader> table_reader;
+  std::unique_ptr<RandomAccessFileReader> file_reader(
+      new RandomAccessFileReader(std::move(file), file_path));
+  s = ioptions.table_factory->NewTableReader(
+      TableReaderOptions(ioptions, env_options, internal_comparator,
+                         false /* skip_filters */, -1 /* level */),
+      std::move(file_reader), file_size, &table_reader,
+      false /* prefetch_index_and_filter_in_cache */);
+  if (!s.ok()) {
+    return s;
+  }
+  s = table_reader->VerifyChecksum();
+  return s;
+}
+
 }  // namespace rocksdb

 #endif  // ROCKSDB_LITE
@@ -20,6 +20,7 @@
 #include "db/log_format.h"
 #include "db/version_set.h"
 #include "rocksdb/cache.h"
+#include "rocksdb/convenience.h"
 #include "rocksdb/env.h"
 #include "rocksdb/table.h"
 #include "rocksdb/write_batch.h"
@@ -152,7 +153,7 @@ class CorruptionTest : public testing::Test {
    struct stat sbuf;
    if (stat(fname.c_str(), &sbuf) != 0) {
      const char* msg = strerror(errno);
-      ASSERT_TRUE(false) << fname << ": " << msg;
+      FAIL() << fname << ": " << msg;
    }

    if (offset < 0) {
@@ -179,6 +180,9 @@ class CorruptionTest : public testing::Test {
    }
    s = WriteStringToFile(Env::Default(), contents, fname);
    ASSERT_TRUE(s.ok()) << s.ToString();
+    Options options;
+    EnvOptions env_options;
+    ASSERT_NOK(VerifySstFileChecksum(options, env_options, fname));
  }

  void Corrupt(FileType filetype, int offset, int bytes_to_corrupt) {
@@ -213,7 +217,7 @@ class CorruptionTest : public testing::Test {
        return;
      }
    }
-    ASSERT_TRUE(false) << "no file found at level";
+    FAIL() << "no file found at level";
  }


@@ -312,6 +316,7 @@ TEST_F(CorruptionTest, TableFile) {

  Corrupt(kTableFile, 100, 1);
  Check(99, 99);
+  ASSERT_NOK(dbi->VerifyChecksum());
 }

 TEST_F(CorruptionTest, TableFileIndexData) {
@@ -327,9 +332,11 @@ TEST_F(CorruptionTest, TableFileIndexData) {
  // corrupt an index block of an entire file
  Corrupt(kTableFile, -2000, 500);
  Reopen();
+  dbi = reinterpret_cast<DBImpl*>(db_);
  // one full file should be readable, since only one was corrupted
  // the other file should be fully non-readable, since index was corrupted
  Check(5000, 5000);
+  ASSERT_NOK(dbi->VerifyChecksum());
 }

 TEST_F(CorruptionTest, MissingDescriptor) {
@@ -389,10 +396,12 @@ TEST_F(CorruptionTest, CompactionInputError) {

  Corrupt(kTableFile, 100, 1);
  Check(9, 9);
+  ASSERT_NOK(dbi->VerifyChecksum());

  // Force compactions by writing lots of values
  Build(10000);
  Check(10000, 10000);
+  ASSERT_NOK(dbi->VerifyChecksum());
 }

 TEST_F(CorruptionTest, CompactionInputErrorParanoid) {
@@ -424,6 +433,7 @@ TEST_F(CorruptionTest, CompactionInputErrorParanoid) {

  CorruptTableFileAtLevel(0, 100, 1);
  Check(9, 9);
+  ASSERT_NOK(dbi->VerifyChecksum());

  // Write must eventually fail because of corrupted table
  Status s;
@@ -445,6 +455,7 @@ TEST_F(CorruptionTest, UnrelatedKeys) {
  DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
  dbi->TEST_FlushMemTable();
  Corrupt(kTableFile, 100, 1);
+  ASSERT_NOK(dbi->VerifyChecksum());

  std::string tmp1, tmp2;
  ASSERT_OK(db_->Put(WriteOptions(), Key(1000, &tmp1), Value(1000, &tmp2)));
@@ -175,6 +175,8 @@ TEST_F(DBBasicTest, LevelLimitReopen) {
  int i = 0;
  while (NumTableFilesAtLevel(2, 1) == 0) {
    ASSERT_OK(Put(1, Key(i++), value));
+    dbfull()->TEST_WaitForFlushMemTable();
+    dbfull()->TEST_WaitForCompact();
  }

  options.num_levels = 1;
@@ -358,7 +360,6 @@ TEST_F(DBBasicTest, FLUSH) {
    WriteOptions writeOpt = WriteOptions();
    writeOpt.disableWAL = true;
    SetPerfLevel(kEnableTime);
-    ;
    ASSERT_OK(dbfull()->Put(writeOpt, handles_[1], "foo", "v1"));
    // this will now also flush the last 2 writes
    ASSERT_OK(Flush(1));
@@ -367,6 +368,7 @@ TEST_F(DBBasicTest, FLUSH) {
    get_perf_context()->Reset();
    Get(1, "foo");
    ASSERT_TRUE((int)get_perf_context()->get_from_output_files_time > 0);
+    ASSERT_EQ(2, (int)get_perf_context()->get_read_bytes);

    ReopenWithColumnFamilies({"default", "pikachu"}, CurrentOptions());
    ASSERT_EQ("v1", Get(1, "foo"));
@@ -723,6 +725,7 @@ TEST_F(DBBasicTest, FlushOneColumnFamily) {
 TEST_F(DBBasicTest, MultiGetSimple) {
  do {
    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    SetPerfLevel(kEnableCount);
    ASSERT_OK(Put(1, "k1", "v1"));
    ASSERT_OK(Put(1, "k2", "v2"));
    ASSERT_OK(Put(1, "k3", "v3"));
@@ -736,12 +739,15 @@ TEST_F(DBBasicTest, MultiGetSimple) {
    std::vector<std::string> values(20, "Temporary data to be overwritten");
    std::vector<ColumnFamilyHandle*> cfs(keys.size(), handles_[1]);

+    get_perf_context()->Reset();
    std::vector<Status> s = db_->MultiGet(ReadOptions(), cfs, keys, &values);
    ASSERT_EQ(values.size(), keys.size());
    ASSERT_EQ(values[0], "v1");
    ASSERT_EQ(values[1], "v2");
    ASSERT_EQ(values[2], "v3");
    ASSERT_EQ(values[4], "v5");
+    // four kv pairs * two bytes per value
+    ASSERT_EQ(8, (int)get_perf_context()->multiget_read_bytes);

    ASSERT_OK(s[0]);
    ASSERT_OK(s[1]);
@@ -749,6 +755,7 @@ TEST_F(DBBasicTest, MultiGetSimple) {
    ASSERT_TRUE(s[3].IsNotFound());
    ASSERT_OK(s[4]);
    ASSERT_TRUE(s[5].IsNotFound());
+    SetPerfLevel(kDisable);
  } while (ChangeCompactOptions());
 }

@@ -785,36 +792,30 @@ TEST_F(DBBasicTest, MultiGetEmpty) {
 TEST_F(DBBasicTest, ChecksumTest) {
  BlockBasedTableOptions table_options;
  Options options = CurrentOptions();
+  // change when new checksum type added
+  int max_checksum = static_cast<int>(kxxHash);
+  const int kNumPerFile = 2;

-  table_options.checksum = kCRC32c;
-  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
-  Reopen(options);
-  ASSERT_OK(Put("a", "b"));
-  ASSERT_OK(Put("c", "d"));
-  ASSERT_OK(Flush());  // table with crc checksum
+  // generate one table with each type of checksum
+  for (int i = 0; i <= max_checksum; ++i) {
+    table_options.checksum = static_cast<ChecksumType>(i);
+    options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+    Reopen(options);
+    for (int j = 0; j < kNumPerFile; ++j) {
+      ASSERT_OK(Put(Key(i * kNumPerFile + j), Key(i * kNumPerFile + j)));
+    }
+    ASSERT_OK(Flush());
+  }

-  table_options.checksum = kxxHash;
-  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
-  Reopen(options);
-  ASSERT_OK(Put("e", "f"));
-  ASSERT_OK(Put("g", "h"));
-  ASSERT_OK(Flush());  // table with xxhash checksum
-
-  table_options.checksum = kCRC32c;
-  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
-  Reopen(options);
-  ASSERT_EQ("b", Get("a"));
-  ASSERT_EQ("d", Get("c"));
-  ASSERT_EQ("f", Get("e"));
-  ASSERT_EQ("h", Get("g"));
-
-  table_options.checksum = kCRC32c;
-  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
-  Reopen(options);
-  ASSERT_EQ("b", Get("a"));
-  ASSERT_EQ("d", Get("c"));
-  ASSERT_EQ("f", Get("e"));
-  ASSERT_EQ("h", Get("g"));
+  // verify data with each type of checksum
+  for (int i = 0; i <= kxxHash; ++i) {
+    table_options.checksum = static_cast<ChecksumType>(i);
+    options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+    Reopen(options);
+    for (int j = 0; j < (max_checksum + 1) * kNumPerFile; ++j) {
+      ASSERT_EQ(Key(j), Get(Key(j)));
+    }
+  }
 }

 // On Windows you can have either memory mapped file or a file
@@ -497,7 +497,7 @@ TEST_F(DBBlockCacheTest, CompressedCache) {
        options.compression = kNoCompression;
        break;
      default:
-        ASSERT_TRUE(false);
+        FAIL();
    }
    CreateAndReopenWithCF({"pikachu"}, options);
    // default column family doesn't have block cache
@@ -560,7 +560,7 @@ TEST_F(DBBlockCacheTest, CompressedCache) {
        ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_HIT), 0);
        break;
      default:
-        ASSERT_TRUE(false);
+        FAIL();
    }

    options.create_if_missing = true;
@@ -2684,6 +2684,46 @@ TEST_P(DBCompactionTestWithParam, IntraL0CompactionDoesNotObsoleteDeletions) {
  ASSERT_TRUE(db_->Get(roptions, Key(0), &result).IsNotFound());
 }

+TEST_F(DBCompactionTest, OptimizedDeletionObsoleting) {
+  // Deletions can be dropped when compacted to non-last level if they fall
+  // outside the lower-level files' key-ranges.
+  const int kNumL0Files = 4;
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = kNumL0Files;
+  options.statistics = rocksdb::CreateDBStatistics();
+  DestroyAndReopen(options);
+
+  // put key 1 and 3 in separate L1, L2 files.
+  // So key 0, 2, and 4+ fall outside these levels' key-ranges.
+  for (int level = 2; level >= 1; --level) {
+    for (int i = 0; i < 2; ++i) {
+      Put(Key(2 * i + 1), "val");
+      Flush();
+    }
+    MoveFilesToLevel(level);
+    ASSERT_EQ(2, NumTableFilesAtLevel(level));
+  }
+
+  // Delete keys in range [1, 4]. These L0 files will be compacted with L1:
+  // - Tombstones for keys 2 and 4 can be dropped early.
+  // - Tombstones for keys 1 and 3 must be kept due to L2 files' key-ranges.
+  for (int i = 0; i < kNumL0Files; ++i) {
+    Put(Key(0), "val");  // sentinel to prevent trivial move
+    Delete(Key(i + 1));
+    Flush();
+  }
+  dbfull()->TEST_WaitForCompact();
+
+  for (int i = 0; i < kNumL0Files; ++i) {
+    std::string value;
+    ASSERT_TRUE(db_->Get(ReadOptions(), Key(i + 1), &value).IsNotFound());
+  }
+  ASSERT_EQ(2, options.statistics->getTickerCount(
+                   COMPACTION_OPTIMIZED_DEL_DROP_OBSOLETE));
+  ASSERT_EQ(2,
+            options.statistics->getTickerCount(COMPACTION_KEY_DROP_OBSOLETE));
+}
+
 INSTANTIATE_TEST_CASE_P(DBCompactionTestWithParam, DBCompactionTestWithParam,
                        ::testing::Values(std::make_tuple(1, true),
                                          std::make_tuple(1, false),
@@ -1,9 +1,7 @@
 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
-//  This source code is licensed under the BSD-style license found in the
-//  LICENSE file in the root directory of this source tree. An additional grant
-//  of patent rights can be found in the PATENTS file in the same directory.
-//  This source code is also licensed under the GPLv2 license found in the
-//  COPYING file in the root directory of this source tree.
+//  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/db_test_util.h"
 #include "port/stack_trace.h"
@@ -67,6 +67,7 @@
 #include "port/port.h"
 #include "rocksdb/cache.h"
 #include "rocksdb/compaction_filter.h"
+#include "rocksdb/convenience.h"
 #include "rocksdb/db.h"
 #include "rocksdb/env.h"
 #include "rocksdb/merge_operator.h"
@@ -80,6 +81,7 @@
 #include "table/merging_iterator.h"
 #include "table/table_builder.h"
 #include "table/two_level_iterator.h"
+#include "tools/sst_dump_tool_imp.h"
 #include "util/auto_roll_logger.h"
 #include "util/autovector.h"
 #include "util/build_version.h"
@@ -168,6 +170,7 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname)
      last_batch_group_size_(0),
      unscheduled_flushes_(0),
      unscheduled_compactions_(0),
+      bg_bottom_compaction_scheduled_(0),
      bg_compaction_scheduled_(0),
      num_running_compactions_(0),
      bg_flush_scheduled_(0),
@@ -242,7 +245,8 @@ void DBImpl::CancelAllBackgroundWork(bool wait) {
    return;
  }
  // Wait for background work to finish
-  while (bg_compaction_scheduled_ || bg_flush_scheduled_) {
+  while (bg_bottom_compaction_scheduled_ || bg_compaction_scheduled_ ||
+         bg_flush_scheduled_) {
    bg_cv_.Wait();
  }
 }
@@ -252,15 +256,18 @@ DBImpl::~DBImpl() {
  // marker. After this we do a variant of the waiting and unschedule work
  // (to consider: moving all the waiting into CancelAllBackgroundWork(true))
  CancelAllBackgroundWork(false);
+  int bottom_compactions_unscheduled =
+      env_->UnSchedule(this, Env::Priority::BOTTOM);
  int compactions_unscheduled = env_->UnSchedule(this, Env::Priority::LOW);
  int flushes_unscheduled = env_->UnSchedule(this, Env::Priority::HIGH);
  mutex_.Lock();
+  bg_bottom_compaction_scheduled_ -= bottom_compactions_unscheduled;
  bg_compaction_scheduled_ -= compactions_unscheduled;
  bg_flush_scheduled_ -= flushes_unscheduled;

  // Wait for background work to finish
-  while (bg_compaction_scheduled_ || bg_flush_scheduled_ ||
-         bg_purge_scheduled_) {
+  while (bg_bottom_compaction_scheduled_ || bg_compaction_scheduled_ ||
+         bg_flush_scheduled_ || bg_purge_scheduled_) {
    TEST_SYNC_POINT("DBImpl::~DBImpl:WaitJob");
    bg_cv_.Wait();
  }
@@ -983,6 +990,7 @@ Status DBImpl::GetImpl(const ReadOptions& read_options,
    size_t size = pinnable_val->size();
    RecordTick(stats_, BYTES_READ, size);
    MeasureTime(stats_, BYTES_PER_READ, size);
+    PERF_COUNTER_ADD(get_read_bytes, size);
  }
  return s;
 }
@@ -1110,6 +1118,7 @@ std::vector<Status> DBImpl::MultiGet(
  RecordTick(stats_, NUMBER_MULTIGET_KEYS_READ, num_keys);
  RecordTick(stats_, NUMBER_MULTIGET_BYTES_READ, bytes_read);
  MeasureTime(stats_, BYTES_PER_MULTIGET, bytes_read);
+  PERF_COUNTER_ADD(multiget_read_bytes, bytes_read);
  PERF_TIMER_STOP(get_post_process_time);

  return stat_list;
@@ -1315,6 +1324,11 @@ Status DBImpl::DropColumnFamilyImpl(ColumnFamilyHandle* column_family) {
                                 &edit, &mutex_);
      write_thread_.ExitUnbatched(&w);
    }
+    if (s.ok()) {
+      auto* mutable_cf_options = cfd->GetLatestMutableCFOptions();
+      max_total_in_memory_state_ -= mutable_cf_options->write_buffer_size *
+                                    mutable_cf_options->max_write_buffer_number;
+    }

    if (!cf_support_snapshot) {
      // Dropped Column Family doesn't support snapshot. Need to recalculate
@@ -1336,9 +1350,6 @@ Status DBImpl::DropColumnFamilyImpl(ColumnFamilyHandle* column_family) {
    // later inside db_mutex.
    EraseThreadStatusCfInfo(cfd);
    assert(cfd->IsDropped());
-    auto* mutable_cf_options = cfd->GetLatestMutableCFOptions();
-    max_total_in_memory_state_ -= mutable_cf_options->write_buffer_size *
-                                  mutable_cf_options->max_write_buffer_number;
    ROCKS_LOG_INFO(immutable_db_options_.info_log,
                   "Dropped column family with id %u\n", cfd->GetID());
  } else {
@@ -1402,8 +1413,7 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
    return NewDBIterator(
        env_, read_options, *cfd->ioptions(), cfd->user_comparator(), iter,
        kMaxSequenceNumber,
-        sv->mutable_cf_options.max_sequential_skip_in_iterations,
-        sv->version_number);
+        sv->mutable_cf_options.max_sequential_skip_in_iterations);
 #endif
  } else {
    SequenceNumber latest_snapshot = versions_->LastSequence();
@@ -1458,9 +1468,10 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
    // likely that any iterator pointer is close to the iterator it points to so
    // that they are likely to be in the same cache line and/or page.
    ArenaWrappedDBIter* db_iter = NewArenaWrappedDbIterator(
-        env_, read_options, *cfd->ioptions(), cfd->user_comparator(), snapshot,
+        env_, read_options, *cfd->ioptions(), snapshot,
        sv->mutable_cf_options.max_sequential_skip_in_iterations,
-        sv->version_number);
+        sv->version_number,
+        ((read_options.snapshot != nullptr) ? nullptr : this), cfd);

    InternalIterator* internal_iter =
        NewInternalIterator(read_options, cfd, sv, db_iter->GetArena(),
@@ -1511,8 +1522,7 @@ Status DBImpl::NewIterators(
      iterators->push_back(NewDBIterator(
          env_, read_options, *cfd->ioptions(), cfd->user_comparator(), iter,
          kMaxSequenceNumber,
-          sv->mutable_cf_options.max_sequential_skip_in_iterations,
-          sv->version_number));
+          sv->mutable_cf_options.max_sequential_skip_in_iterations));
    }
 #endif
  } else {
@@ -1530,9 +1540,10 @@ Status DBImpl::NewIterators(
              : latest_snapshot;

      ArenaWrappedDBIter* db_iter = NewArenaWrappedDbIterator(
-          env_, read_options, *cfd->ioptions(), cfd->user_comparator(),
-          snapshot, sv->mutable_cf_options.max_sequential_skip_in_iterations,
-          sv->version_number);
+          env_, read_options, *cfd->ioptions(), snapshot,
+          sv->mutable_cf_options.max_sequential_skip_in_iterations,
+          sv->version_number,
+          ((read_options.snapshot != nullptr) ? nullptr : this), cfd);
      InternalIterator* internal_iter =
          NewInternalIterator(read_options, cfd, sv, db_iter->GetArena(),
                              db_iter->GetRangeDelAggregator());
@@ -2293,7 +2304,7 @@ Status DestroyDB(const std::string& dbname, const Options& options) {
    // Delete log files in the WAL dir
    for (const auto& file : walDirFiles) {
      if (ParseFileName(file, &number, &type) && type == kLogFile) {
-        Status del = env->DeleteFile(soptions.wal_dir + "/" + file);
+        Status del = env->DeleteFile(LogFileName(soptions.wal_dir, number));
        if (result.ok() && !del.ok()) {
          result = del;
        }
@@ -2735,6 +2746,54 @@ Status DBImpl::IngestExternalFile(
  return status;
 }

+Status DBImpl::VerifyChecksum() {
+  Status s;
+  Options options;
+  EnvOptions env_options;
+  std::vector<ColumnFamilyData*> cfd_list;
+  {
+    InstrumentedMutexLock l(&mutex_);
+    for (auto cfd : *versions_->GetColumnFamilySet()) {
+      if (!cfd->IsDropped() && cfd->initialized()) {
+        cfd->Ref();
+        cfd_list.push_back(cfd);
+      }
+    }
+  }
+  std::vector<SuperVersion*> sv_list;
+  for (auto cfd : cfd_list) {
+    sv_list.push_back(cfd->GetReferencedSuperVersion(&mutex_));
+  }
+  for (auto& sv : sv_list) {
+    VersionStorageInfo* vstorage = sv->current->storage_info();
+    for (int i = 0; i < vstorage->num_non_empty_levels() && s.ok(); i++) {
+      for (size_t j = 0; j < vstorage->LevelFilesBrief(i).num_files && s.ok();
+           j++) {
+        const auto& fd = vstorage->LevelFilesBrief(i).files[j].fd;
+        std::string fname = TableFileName(immutable_db_options_.db_paths,
+                                          fd.GetNumber(), fd.GetPathId());
+        s = rocksdb::VerifySstFileChecksum(options, env_options, fname);
+      }
+    }
+    if (!s.ok()) {
+      break;
+    }
+  }
+  {
+    InstrumentedMutexLock l(&mutex_);
+    for (auto sv : sv_list) {
+      if (sv && sv->Unref()) {
+        sv->Cleanup();
+        delete sv;
+      }
+    }
+    for (auto cfd : cfd_list) {
+        cfd->Unref();
+    }
+  }
+  return s;
+}
+
 void DBImpl::NotifyOnExternalFileIngested(
    ColumnFamilyData* cfd, const ExternalSstFileIngestionJob& ingestion_job) {
 #ifndef ROCKSDB_LITE
@@ -235,11 +235,11 @@ class DBImpl : public DB {
      ColumnFamilyHandle* column_family,
      ColumnFamilyMetaData* metadata) override;

-  // experimental API
  Status SuggestCompactRange(ColumnFamilyHandle* column_family,
-                             const Slice* begin, const Slice* end);
+                             const Slice* begin, const Slice* end) override;

-  Status PromoteL0(ColumnFamilyHandle* column_family, int target_level);
+  Status PromoteL0(ColumnFamilyHandle* column_family,
+                   int target_level) override;

  // Similar to Write() but will call the callback once on the single write
  // thread to determine whether it is safe to perform the write.
@@ -293,6 +293,8 @@ class DBImpl : public DB {
      const std::vector<std::string>& external_files,
      const IngestExternalFileOptions& ingestion_options) override;

+  virtual Status VerifyChecksum() override;
+
 #endif  // ROCKSDB_LITE

  // Similar to GetSnapshot(), but also lets the db know that this snapshot
@@ -494,6 +496,12 @@ class DBImpl : public DB {

  const WriteController& write_controller() { return write_controller_; }

+  InternalIterator* NewInternalIterator(const ReadOptions&,
+                                        ColumnFamilyData* cfd,
+                                        SuperVersion* super_version,
+                                        Arena* arena,
+                                        RangeDelAggregator* range_del_agg);
+
  // hollow transactions shell used for recovery.
  // these will then be passed to TransactionDB so that
  // locks can be reacquired before writing can resume.
@@ -552,6 +560,7 @@ class DBImpl : public DB {
  void AddToLogsToFreeQueue(log::Writer* log_writer) {
    logs_to_free_queue_.push_back(log_writer);
  }
+  InstrumentedMutex* mutex() { return &mutex_; }

  Status NewDB();

@@ -566,12 +575,6 @@ class DBImpl : public DB {
  std::unordered_map<std::string, RecoveredTransaction*>
      recovered_transactions_;

-  InternalIterator* NewInternalIterator(const ReadOptions&,
-                                        ColumnFamilyData* cfd,
-                                        SuperVersion* super_version,
-                                        Arena* arena,
-                                        RangeDelAggregator* range_del_agg);
-
  // Except in DB::Open(), WriteOptionsFile can only be called when:
  // Persist options to options file.
  // If need_mutex_lock = false, the method will lock DB mutex.
@@ -613,16 +616,18 @@ class DBImpl : public DB {
  Status WriteImpl(const WriteOptions& options, WriteBatch* updates,
                   WriteCallback* callback = nullptr,
                   uint64_t* log_used = nullptr, uint64_t log_ref = 0,
-                   bool disable_memtable = false);
+                   bool disable_memtable = false, uint64_t* seq_used = nullptr);

  Status PipelinedWriteImpl(const WriteOptions& options, WriteBatch* updates,
                            WriteCallback* callback = nullptr,
                            uint64_t* log_used = nullptr, uint64_t log_ref = 0,
-                            bool disable_memtable = false);
+                            bool disable_memtable = false,
+                            uint64_t* seq_used = nullptr);

  Status WriteImplWALOnly(const WriteOptions& options, WriteBatch* updates,
                          WriteCallback* callback = nullptr,
-                          uint64_t* log_used = nullptr, uint64_t log_ref = 0);
+                          uint64_t* log_used = nullptr, uint64_t log_ref = 0,
+                          uint64_t* seq_used = nullptr);

  uint64_t FindMinLogContainingOutstandingPrep();
  uint64_t FindMinPrepLogReferencedByMemTable();
@@ -630,7 +635,9 @@ class DBImpl : public DB {
 private:
  friend class DB;
  friend class InternalStats;
-  friend class TransactionImpl;
+  friend class PessimisticTransaction;
+  friend class WriteCommittedTxn;
+  friend class WritePreparedTxn;
 #ifndef ROCKSDB_LITE
  friend class ForwardIterator;
 #endif
@@ -655,6 +662,7 @@ class DBImpl : public DB {
    }
  };

+  struct PrepickedCompaction;
  struct PurgeFileInfo;

  // Recover the descriptor from persistent storage.  May do a significant
@@ -796,14 +804,19 @@ class DBImpl : public DB {
  void SchedulePendingPurge(std::string fname, FileType type, uint64_t number,
                            uint32_t path_id, int job_id);
  static void BGWorkCompaction(void* arg);
+  // Runs a pre-chosen universal compaction involving bottom level in a
+  // separate, bottom-pri thread pool.
+  static void BGWorkBottomCompaction(void* arg);
  static void BGWorkFlush(void* db);
  static void BGWorkPurge(void* arg);
  static void UnscheduleCallback(void* arg);
-  void BackgroundCallCompaction(void* arg);
+  void BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
+                                Env::Priority bg_thread_pri);
  void BackgroundCallFlush();
  void BackgroundCallPurge();
  Status BackgroundCompaction(bool* madeProgress, JobContext* job_context,
-                              LogBuffer* log_buffer, void* m = 0);
+                              LogBuffer* log_buffer,
+                              PrepickedCompaction* prepicked_compaction);
  Status BackgroundFlush(bool* madeProgress, JobContext* job_context,
                         LogBuffer* log_buffer);

@@ -1056,6 +1069,10 @@ class DBImpl : public DB {
  int unscheduled_flushes_;
  int unscheduled_compactions_;

+  // count how many background compactions are running or have been scheduled in
+  // the BOTTOM pool
+  int bg_bottom_compaction_scheduled_;
+
  // count how many background compactions are running or have been scheduled
  int bg_compaction_scheduled_;

@@ -1072,7 +1089,7 @@ class DBImpl : public DB {
  int bg_purge_scheduled_;

  // Information for a manual compaction
-  struct ManualCompaction {
+  struct ManualCompactionState {
    ColumnFamilyData* cfd;
    int input_level;
    int output_level;
@@ -1088,13 +1105,21 @@ class DBImpl : public DB {
    InternalKey* manual_end;      // how far we are compacting
    InternalKey tmp_storage;      // Used to keep track of compaction progress
    InternalKey tmp_storage1;     // Used to keep track of compaction progress
-    Compaction* compaction;
  };
-  std::deque<ManualCompaction*> manual_compaction_dequeue_;
+  struct PrepickedCompaction {
+    // background compaction takes ownership of `compaction`.
+    Compaction* compaction;
+    // caller retains ownership of `manual_compaction_state` as it is reused
+    // across background compactions.
+    ManualCompactionState* manual_compaction_state;  // nullptr if non-manual
+  };
+  std::deque<ManualCompactionState*> manual_compaction_dequeue_;

  struct CompactionArg {
+    // caller retains ownership of `db`.
    DBImpl* db;
-    ManualCompaction* m;
+    // background compaction takes ownership of `prepicked_compaction`.
+    PrepickedCompaction* prepicked_compaction;
  };

  // Have we encountered a background error in paranoid mode?
@@ -1228,11 +1253,11 @@ class DBImpl : public DB {

  bool HasPendingManualCompaction();
  bool HasExclusiveManualCompaction();
-  void AddManualCompaction(ManualCompaction* m);
-  void RemoveManualCompaction(ManualCompaction* m);
-  bool ShouldntRunManualCompaction(ManualCompaction* m);
+  void AddManualCompaction(ManualCompactionState* m);
+  void RemoveManualCompaction(ManualCompactionState* m);
+  bool ShouldntRunManualCompaction(ManualCompactionState* m);
  bool HaveManualCompaction(ColumnFamilyData* cfd);
-  bool MCOverlap(ManualCompaction* m, ManualCompaction* m1);
+  bool MCOverlap(ManualCompactionState* m, ManualCompactionState* m1);

  size_t GetWalPreallocateBlockSize(uint64_t write_buffer_size) const;

@@ -612,7 +612,8 @@ Status DBImpl::CompactFilesImpl(
 Status DBImpl::PauseBackgroundWork() {
  InstrumentedMutexLock guard_lock(&mutex_);
  bg_compaction_paused_++;
-  while (bg_compaction_scheduled_ > 0 || bg_flush_scheduled_ > 0) {
+  while (bg_bottom_compaction_scheduled_ > 0 || bg_compaction_scheduled_ > 0 ||
+         bg_flush_scheduled_ > 0) {
    bg_cv_.Wait();
  }
  bg_work_paused_++;
@@ -808,7 +809,7 @@ Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,

  bool scheduled = false;
  bool manual_conflict = false;
-  ManualCompaction manual;
+  ManualCompactionState manual;
  manual.cfd = cfd;
  manual.input_level = input_level;
  manual.output_level = output_level;
@@ -858,7 +859,8 @@ Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
  AddManualCompaction(&manual);
  TEST_SYNC_POINT_CALLBACK("DBImpl::RunManualCompaction:NotScheduled", &mutex_);
  if (exclusive) {
-    while (bg_compaction_scheduled_ > 0) {
+    while (bg_bottom_compaction_scheduled_ > 0 ||
+           bg_compaction_scheduled_ > 0) {
      TEST_SYNC_POINT("DBImpl::RunManualCompaction:WaitScheduled");
      ROCKS_LOG_INFO(
          immutable_db_options_.info_log,
@@ -878,14 +880,14 @@ Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
  while (!manual.done) {
    assert(HasPendingManualCompaction());
    manual_conflict = false;
+    Compaction* compaction;
    if (ShouldntRunManualCompaction(&manual) || (manual.in_progress == true) ||
        scheduled ||
-        ((manual.manual_end = &manual.tmp_storage1)&&(
-             (manual.compaction = manual.cfd->CompactRange(
-                  *manual.cfd->GetLatestMutableCFOptions(), manual.input_level,
-                  manual.output_level, manual.output_path_id, manual.begin,
-                  manual.end, &manual.manual_end, &manual_conflict)) ==
-             nullptr) &&
+        ((manual.manual_end = &manual.tmp_storage1) &&
+         ((compaction = manual.cfd->CompactRange(
+               *manual.cfd->GetLatestMutableCFOptions(), manual.input_level,
+               manual.output_level, manual.output_path_id, manual.begin,
+               manual.end, &manual.manual_end, &manual_conflict)) == nullptr) &&
         manual_conflict)) {
      // exclusive manual compactions should not see a conflict during
      // CompactRange
@@ -898,14 +900,16 @@ Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
        manual.incomplete = false;
      }
    } else if (!scheduled) {
-      if (manual.compaction == nullptr) {
+      if (compaction == nullptr) {
        manual.done = true;
        bg_cv_.SignalAll();
        continue;
      }
      ca = new CompactionArg;
      ca->db = this;
-      ca->m = &manual;
+      ca->prepicked_compaction = new PrepickedCompaction;
+      ca->prepicked_compaction->manual_compaction_state = &manual;
+      ca->prepicked_compaction->compaction = compaction;
      manual.incomplete = false;
      bg_compaction_scheduled_++;
      env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this,
@@ -1047,7 +1051,7 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
         unscheduled_compactions_ > 0) {
    CompactionArg* ca = new CompactionArg;
    ca->db = this;
-    ca->m = nullptr;
+    ca->prepicked_compaction = nullptr;
    bg_compaction_scheduled_++;
    unscheduled_compactions_--;
    env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this,
@@ -1152,7 +1156,23 @@ void DBImpl::BGWorkCompaction(void* arg) {
  delete reinterpret_cast<CompactionArg*>(arg);
  IOSTATS_SET_THREAD_POOL_ID(Env::Priority::LOW);
  TEST_SYNC_POINT("DBImpl::BGWorkCompaction");
-  reinterpret_cast<DBImpl*>(ca.db)->BackgroundCallCompaction(ca.m);
+  auto prepicked_compaction =
+      static_cast<PrepickedCompaction*>(ca.prepicked_compaction);
+  reinterpret_cast<DBImpl*>(ca.db)->BackgroundCallCompaction(
+      prepicked_compaction, Env::Priority::LOW);
+  delete prepicked_compaction;
+}
+
+void DBImpl::BGWorkBottomCompaction(void* arg) {
+  CompactionArg ca = *(static_cast<CompactionArg*>(arg));
+  delete static_cast<CompactionArg*>(arg);
+  IOSTATS_SET_THREAD_POOL_ID(Env::Priority::BOTTOM);
+  TEST_SYNC_POINT("DBImpl::BGWorkBottomCompaction");
+  auto* prepicked_compaction = ca.prepicked_compaction;
+  assert(prepicked_compaction && prepicked_compaction->compaction &&
+         !prepicked_compaction->manual_compaction_state);
+  ca.db->BackgroundCallCompaction(prepicked_compaction, Env::Priority::BOTTOM);
+  delete prepicked_compaction;
 }

 void DBImpl::BGWorkPurge(void* db) {
@@ -1165,8 +1185,11 @@ void DBImpl::BGWorkPurge(void* db) {
 void DBImpl::UnscheduleCallback(void* arg) {
  CompactionArg ca = *(reinterpret_cast<CompactionArg*>(arg));
  delete reinterpret_cast<CompactionArg*>(arg);
-  if ((ca.m != nullptr) && (ca.m->compaction != nullptr)) {
-    delete ca.m->compaction;
+  if (ca.prepicked_compaction != nullptr) {
+    if (ca.prepicked_compaction->compaction != nullptr) {
+      delete ca.prepicked_compaction->compaction;
+    }
+    delete ca.prepicked_compaction;
  }
  TEST_SYNC_POINT("DBImpl::UnscheduleCallback");
 }
@@ -1293,9 +1316,9 @@ void DBImpl::BackgroundCallFlush() {
  }
 }

-void DBImpl::BackgroundCallCompaction(void* arg) {
+void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
+                                      Env::Priority bg_thread_pri) {
  bool made_progress = false;
-  ManualCompaction* m = reinterpret_cast<ManualCompaction*>(arg);
  JobContext job_context(next_job_id_.fetch_add(1), true);
  TEST_SYNC_POINT("BackgroundCallCompaction:0");
  MaybeDumpStats();
@@ -1313,9 +1336,11 @@ void DBImpl::BackgroundCallCompaction(void* arg) {
    auto pending_outputs_inserted_elem =
        CaptureCurrentFileNumberInPendingOutputs();

-    assert(bg_compaction_scheduled_);
-    Status s =
-        BackgroundCompaction(&made_progress, &job_context, &log_buffer, m);
+    assert((bg_thread_pri == Env::Priority::BOTTOM &&
+            bg_bottom_compaction_scheduled_) ||
+           (bg_thread_pri == Env::Priority::LOW && bg_compaction_scheduled_));
+    Status s = BackgroundCompaction(&made_progress, &job_context, &log_buffer,
+                                    prepicked_compaction);
    TEST_SYNC_POINT("BackgroundCallCompaction:1");
    if (!s.ok() && !s.IsShutdownInProgress()) {
      // Wait a little bit before retrying background compaction in
@@ -1361,17 +1386,24 @@ void DBImpl::BackgroundCallCompaction(void* arg) {

    assert(num_running_compactions_ > 0);
    num_running_compactions_--;
-    bg_compaction_scheduled_--;
+    if (bg_thread_pri == Env::Priority::LOW) {
+      bg_compaction_scheduled_--;
+    } else {
+      assert(bg_thread_pri == Env::Priority::BOTTOM);
+      bg_bottom_compaction_scheduled_--;
+    }

    versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();

    // See if there's more work to be done
    MaybeScheduleFlushOrCompaction();
-    if (made_progress || bg_compaction_scheduled_ == 0 ||
+    if (made_progress ||
+        (bg_compaction_scheduled_ == 0 &&
+         bg_bottom_compaction_scheduled_ == 0) ||
        HasPendingManualCompaction()) {
      // signal if
      // * made_progress -- need to wakeup DelayWrite
-      // * bg_compaction_scheduled_ == 0 -- need to wakeup ~DBImpl
+      // * bg_{bottom,}_compaction_scheduled_ == 0 -- need to wakeup ~DBImpl
      // * HasPendingManualCompaction -- need to wakeup RunManualCompaction
      // If none of this is true, there is no need to signal since nobody is
      // waiting for it
@@ -1386,14 +1418,23 @@ void DBImpl::BackgroundCallCompaction(void* arg) {

 Status DBImpl::BackgroundCompaction(bool* made_progress,
                                    JobContext* job_context,
-                                    LogBuffer* log_buffer, void* arg) {
-  ManualCompaction* manual_compaction =
-      reinterpret_cast<ManualCompaction*>(arg);
+                                    LogBuffer* log_buffer,
+                                    PrepickedCompaction* prepicked_compaction) {
+  ManualCompactionState* manual_compaction =
+      prepicked_compaction == nullptr
+          ? nullptr
+          : prepicked_compaction->manual_compaction_state;
  *made_progress = false;
  mutex_.AssertHeld();
  TEST_SYNC_POINT("DBImpl::BackgroundCompaction:Start");

  bool is_manual = (manual_compaction != nullptr);
+  unique_ptr<Compaction> c;
+  if (prepicked_compaction != nullptr &&
+      prepicked_compaction->compaction != nullptr) {
+    c.reset(prepicked_compaction->compaction);
+  }
+  bool is_prepicked = is_manual || c;

  // (manual_compaction->in_progress == false);
  bool trivial_move_disallowed =
@@ -1410,7 +1451,6 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
      manual_compaction->status = status;
      manual_compaction->done = true;
      manual_compaction->in_progress = false;
-      delete manual_compaction->compaction;
      manual_compaction = nullptr;
    }
    return status;
@@ -1421,13 +1461,11 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    manual_compaction->in_progress = true;
  }

-  unique_ptr<Compaction> c;
  // InternalKey manual_end_storage;
  // InternalKey* manual_end = &manual_end_storage;
  if (is_manual) {
-    ManualCompaction* m = manual_compaction;
+    ManualCompactionState* m = manual_compaction;
    assert(m->in_progress);
-    c.reset(std::move(m->compaction));
    if (!c) {
      m->done = true;
      m->manual_end = nullptr;
@@ -1449,7 +1487,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
               ? "(end)"
               : m->manual_end->DebugString().c_str()));
    }
-  } else if (!compaction_queue_.empty()) {
+  } else if (!is_prepicked && !compaction_queue_.empty()) {
    if (HaveManualCompaction(compaction_queue_.front())) {
      // Can't compact right now, but try again later
      TEST_SYNC_POINT("DBImpl::BackgroundCompaction()::Conflict");
@@ -1601,6 +1639,28 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,

    // Clear Instrument
    ThreadStatusUtil::ResetThreadStatus();
+  } else if (c->column_family_data()->ioptions()->compaction_style ==
+                 kCompactionStyleUniversal &&
+             !is_prepicked && c->output_level() > 0 &&
+             c->output_level() ==
+                 c->column_family_data()
+                     ->current()
+                     ->storage_info()
+                     ->MaxOutputLevel(
+                         immutable_db_options_.allow_ingest_behind) &&
+             env_->GetBackgroundThreads(Env::Priority::BOTTOM) > 0) {
+    // Forward universal compactions involving last level to the bottom pool
+    // if it exists, such that long-running compactions can't block short-
+    // lived ones, like L0->L0s.
+    TEST_SYNC_POINT("DBImpl::BackgroundCompaction:ForwardToBottomPriPool");
+    CompactionArg* ca = new CompactionArg;
+    ca->db = this;
+    ca->prepicked_compaction = new PrepickedCompaction;
+    ca->prepicked_compaction->compaction = c.release();
+    ca->prepicked_compaction->manual_compaction_state = nullptr;
+    ++bg_bottom_compaction_scheduled_;
+    env_->Schedule(&DBImpl::BGWorkBottomCompaction, ca, Env::Priority::BOTTOM,
+                   this, &DBImpl::UnscheduleCallback);
  } else {
    int output_level  __attribute__((unused)) = c->output_level();
    TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:NonTrivial",
@@ -1664,7 +1724,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
  }

  if (is_manual) {
-    ManualCompaction* m = manual_compaction;
+    ManualCompactionState* m = manual_compaction;
    if (!status.ok()) {
      m->status = status;
      m->done = true;
@@ -1707,13 +1767,13 @@ bool DBImpl::HasPendingManualCompaction() {
  return (!manual_compaction_dequeue_.empty());
 }

-void DBImpl::AddManualCompaction(DBImpl::ManualCompaction* m) {
+void DBImpl::AddManualCompaction(DBImpl::ManualCompactionState* m) {
  manual_compaction_dequeue_.push_back(m);
 }

-void DBImpl::RemoveManualCompaction(DBImpl::ManualCompaction* m) {
+void DBImpl::RemoveManualCompaction(DBImpl::ManualCompactionState* m) {
  // Remove from queue
-  std::deque<ManualCompaction*>::iterator it =
+  std::deque<ManualCompactionState*>::iterator it =
      manual_compaction_dequeue_.begin();
  while (it != manual_compaction_dequeue_.end()) {
    if (m == (*it)) {
@@ -1726,16 +1786,17 @@ void DBImpl::RemoveManualCompaction(DBImpl::ManualCompaction* m) {
  return;
 }

-bool DBImpl::ShouldntRunManualCompaction(ManualCompaction* m) {
+bool DBImpl::ShouldntRunManualCompaction(ManualCompactionState* m) {
  if (num_running_ingest_file_ > 0) {
    // We need to wait for other IngestExternalFile() calls to finish
    // before running a manual compaction.
    return true;
  }
  if (m->exclusive) {
-    return (bg_compaction_scheduled_ > 0);
+    return (bg_bottom_compaction_scheduled_ > 0 ||
+            bg_compaction_scheduled_ > 0);
  }
-  std::deque<ManualCompaction*>::iterator it =
+  std::deque<ManualCompactionState*>::iterator it =
      manual_compaction_dequeue_.begin();
  bool seen = false;
  while (it != manual_compaction_dequeue_.end()) {
@@ -1756,7 +1817,7 @@ bool DBImpl::ShouldntRunManualCompaction(ManualCompaction* m) {

 bool DBImpl::HaveManualCompaction(ColumnFamilyData* cfd) {
  // Remove from priority queue
-  std::deque<ManualCompaction*>::iterator it =
+  std::deque<ManualCompactionState*>::iterator it =
      manual_compaction_dequeue_.begin();
  while (it != manual_compaction_dequeue_.end()) {
    if ((*it)->exclusive) {
@@ -1774,7 +1835,7 @@ bool DBImpl::HaveManualCompaction(ColumnFamilyData* cfd) {

 bool DBImpl::HasExclusiveManualCompaction() {
  // Remove from priority queue
-  std::deque<ManualCompaction*>::iterator it =
+  std::deque<ManualCompactionState*>::iterator it =
      manual_compaction_dequeue_.begin();
  while (it != manual_compaction_dequeue_.end()) {
    if ((*it)->exclusive) {
@@ -1785,7 +1846,7 @@ bool DBImpl::HasExclusiveManualCompaction() {
  return false;
 }

-bool DBImpl::MCOverlap(ManualCompaction* m, ManualCompaction* m1) {
+bool DBImpl::MCOverlap(ManualCompactionState* m, ManualCompactionState* m1) {
  if ((m->exclusive) || (m1->exclusive)) {
    return true;
  }
@@ -112,7 +112,9 @@ Status DBImpl::TEST_WaitForCompact() {
  // OR flush to finish.

  InstrumentedMutexLock l(&mutex_);
-  while ((bg_compaction_scheduled_ || bg_flush_scheduled_) && bg_error_.ok()) {
+  while ((bg_bottom_compaction_scheduled_ || bg_compaction_scheduled_ ||
+          bg_flush_scheduled_) &&
+         bg_error_.ok()) {
    bg_cv_.Wait();
  }
  return bg_error_;
@@ -368,6 +368,9 @@ void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
    candidate_files.emplace_back(
        MakeTableFileName(kDumbDbName, file->fd.GetNumber()),
        file->fd.GetPathId());
+    if (file->table_reader_handle) {
+      table_cache_->Release(file->table_reader_handle);
+    }
    delete file;
  }

@@ -58,7 +58,7 @@ Iterator* DBImplReadOnly::NewIterator(const ReadOptions& read_options,
  SuperVersion* super_version = cfd->GetSuperVersion()->Ref();
  SequenceNumber latest_snapshot = versions_->LastSequence();
  auto db_iter = NewArenaWrappedDbIterator(
-      env_, read_options, *cfd->ioptions(), cfd->user_comparator(),
+      env_, read_options, *cfd->ioptions(),
      (read_options.snapshot != nullptr
           ? reinterpret_cast<const SnapshotImpl*>(read_options.snapshot)
                 ->number_
@@ -87,7 +87,7 @@ Status DBImplReadOnly::NewIterators(
    auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
    auto* sv = cfd->GetSuperVersion()->Ref();
    auto* db_iter = NewArenaWrappedDbIterator(
-        env_, read_options, *cfd->ioptions(), cfd->user_comparator(),
+        env_, read_options, *cfd->ioptions(),
        (read_options.snapshot != nullptr
             ? reinterpret_cast<const SnapshotImpl*>(read_options.snapshot)
                   ->number_
@@ -60,7 +60,7 @@ Status DBImpl::WriteWithCallback(const WriteOptions& write_options,
 Status DBImpl::WriteImpl(const WriteOptions& write_options,
                         WriteBatch* my_batch, WriteCallback* callback,
                         uint64_t* log_used, uint64_t log_ref,
-                         bool disable_memtable) {
+                         bool disable_memtable, uint64_t* seq_used) {
  if (my_batch == nullptr) {
    return Status::Corruption("Batch is nullptr!");
  }
@@ -79,12 +79,12 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,

  if (concurrent_prepare_ && disable_memtable) {
    return WriteImplWALOnly(write_options, my_batch, callback, log_used,
-                            log_ref);
+                            log_ref, seq_used);
  }

  if (immutable_db_options_.enable_pipelined_write) {
    return PipelinedWriteImpl(write_options, my_batch, callback, log_used,
-                              log_ref, disable_memtable);
+                              log_ref, disable_memtable, seq_used);
  }

  PERF_TIMER_GUARD(write_pre_and_post_process_time);
@@ -127,6 +127,9 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
    if (log_used != nullptr) {
      *log_used = w.log_used;
    }
+    if (seq_used != nullptr) {
+      *seq_used = w.sequence;
+    }
    // write is complete and leader has updated sequence
    return w.FinalStatus();
  }
@@ -278,6 +281,9 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
              write_options.ignore_missing_column_families, 0 /*log_number*/,
              this, true /*concurrent_memtable_writes*/);
        }
+        if (seq_used != nullptr) {
+          *seq_used = w.sequence;
+        }
      }
    }
  }
@@ -313,7 +319,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
      versions_->SetLastSequence(last_sequence);
    }
    MemTableInsertStatusCheck(w.status);
-    write_thread_.ExitAsBatchGroupLeader(write_group, status);
+    write_thread_.ExitAsBatchGroupLeader(write_group, w.status);
  }

  if (status.ok()) {
@@ -325,7 +331,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
 Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
                                  WriteBatch* my_batch, WriteCallback* callback,
                                  uint64_t* log_used, uint64_t log_ref,
-                                  bool disable_memtable) {
+                                  bool disable_memtable, uint64_t* seq_used) {
  PERF_TIMER_GUARD(write_pre_and_post_process_time);
  StopWatch write_sw(env_, immutable_db_options_.statistics.get(), DB_WRITE);

@@ -440,6 +446,9 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
      write_thread_.ExitAsMemTableWriter(&w, *w.write_group);
    }
  }
+  if (seq_used != nullptr) {
+    *seq_used = w.sequence;
+  }

  assert(w.state == WriteThread::STATE_COMPLETED);
  return w.FinalStatus();
@@ -447,7 +456,8 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,

 Status DBImpl::WriteImplWALOnly(const WriteOptions& write_options,
                                WriteBatch* my_batch, WriteCallback* callback,
-                                uint64_t* log_used, uint64_t log_ref) {
+                                uint64_t* log_used, uint64_t log_ref,
+                                uint64_t* seq_used) {
  Status status;
  PERF_TIMER_GUARD(write_pre_and_post_process_time);
  WriteThread::Writer w(write_options, my_batch, callback, log_ref,
@@ -464,6 +474,9 @@ Status DBImpl::WriteImplWALOnly(const WriteOptions& write_options,
    if (log_used != nullptr) {
      *log_used = w.log_used;
    }
+    if (seq_used != nullptr) {
+      *seq_used = w.sequence;
+    }
    return w.FinalStatus();
  }
  // else we are the leader of the write batch group
@@ -509,6 +522,13 @@ Status DBImpl::WriteImplWALOnly(const WriteOptions& write_options,
  // wal_write_mutex_ to ensure ordered events in WAL
  status = ConcurrentWriteToWAL(write_group, log_used, &last_sequence,
                                0 /*total_count*/);
+  auto curr_seq = last_sequence + 1;
+  for (auto* writer : write_group) {
+    if (writer->CheckCallback(this)) {
+      writer->sequence = curr_seq;
+      curr_seq += WriteBatchInternal::Count(writer->batch);
+    }
+  }
  if (status.ok() && write_options.sync) {
    // Requesting sync with concurrent_prepare_ is expected to be very rare. We
    // hance provide a simple implementation that is not necessarily efficient.
@@ -523,10 +543,13 @@ Status DBImpl::WriteImplWALOnly(const WriteOptions& write_options,
  if (!w.CallbackFailed()) {
    WriteCallbackStatusCheck(status);
  }
-  nonmem_write_thread_.ExitAsBatchGroupLeader(write_group, status);
+  nonmem_write_thread_.ExitAsBatchGroupLeader(write_group, w.status);
  if (status.ok()) {
    status = w.FinalStatus();
  }
+  if (seq_used != nullptr) {
+    *seq_used = w.sequence;
+  }
  return status;
 }

@@ -1058,7 +1081,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
  SuperVersion* new_superversion = nullptr;
  const MutableCFOptions mutable_cf_options = *cfd->GetLatestMutableCFOptions();

-  // Set current_memtble_info for memtable sealed callback
+  // Set memtable_info for memtable sealed callback
 #ifndef ROCKSDB_LITE
  MemTableInfo memtable_info;
  memtable_info.cf_name = cfd->GetName();
@@ -204,7 +204,6 @@ TEST_F(DBIOFailureTest, ManifestWriteError) {
    ASSERT_EQ("bar2", Get("foo2"));
  }
 }
-#endif  // ROCKSDB_LITE

 TEST_F(DBIOFailureTest, PutFailsParanoid) {
  // Test the following:
@@ -559,6 +558,7 @@ TEST_F(DBIOFailureTest, CompactionSstSyncError) {
  ASSERT_EQ("bar3", Get(1, "foo"));
 }
 #endif  // !(defined NDEBUG) || !defined(OS_WIN)
+#endif  // ROCKSDB_LITE
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -86,6 +86,7 @@ class DBIter: public Iterator {
      RecordTick(global_statistics, NUMBER_DB_PREV, prev_count_);
      RecordTick(global_statistics, NUMBER_DB_PREV_FOUND, prev_found_count_);
      RecordTick(global_statistics, ITER_BYTES_READ, bytes_read_);
+      PERF_COUNTER_ADD(iter_read_bytes, bytes_read_);
      ResetCounters();
    }

@@ -101,12 +102,12 @@ class DBIter: public Iterator {
    uint64_t bytes_read_;
  };

-  DBIter(Env* env, const ReadOptions& read_options,
+  DBIter(Env* _env, const ReadOptions& read_options,
         const ImmutableCFOptions& cf_options, const Comparator* cmp,
         InternalIterator* iter, SequenceNumber s, bool arena_mode,
-         uint64_t max_sequential_skip_in_iterations, uint64_t version_number)
+         uint64_t max_sequential_skip_in_iterations)
      : arena_mode_(arena_mode),
-        env_(env),
+        env_(_env),
        logger_(cf_options.info_log),
        user_comparator_(cmp),
        merge_operator_(cf_options.merge_operator),
@@ -116,7 +117,6 @@ class DBIter: public Iterator {
        valid_(false),
        current_entry_is_merged_(false),
        statistics_(cf_options.statistics),
-        version_number_(version_number),
        iterate_upper_bound_(read_options.iterate_upper_bound),
        prefix_same_as_start_(read_options.prefix_same_as_start),
        pin_thru_lifetime_(read_options.pin_data),
@@ -188,10 +188,7 @@ class DBIter: public Iterator {
    }
    if (prop_name == "rocksdb.iterator.super-version-number") {
      // First try to pass the value returned from inner iterator.
-      if (!iter_->GetProperty(prop_name, prop).ok()) {
-        *prop = ToString(version_number_);
-      }
-      return Status::OK();
+      return iter_->GetProperty(prop_name, prop);
    } else if (prop_name == "rocksdb.iterator.is-key-pinned") {
      if (valid_) {
        *prop = (pin_thru_lifetime_ && saved_key_.IsKeyPinned()) ? "1" : "0";
@@ -209,6 +206,9 @@ class DBIter: public Iterator {
  virtual void SeekForPrev(const Slice& target) override;
  virtual void SeekToFirst() override;
  virtual void SeekToLast() override;
+  Env* env() { return env_; }
+  void set_sequence(uint64_t s) { sequence_ = s; }
+  void set_valid(bool v) { valid_ = v; }

 private:
  void ReverseToForward();
@@ -260,7 +260,7 @@ class DBIter: public Iterator {
  const Comparator* const user_comparator_;
  const MergeOperator* const merge_operator_;
  InternalIterator* iter_;
-  SequenceNumber const sequence_;
+  SequenceNumber sequence_;

  Status status_;
  IterKey saved_key_;
@@ -274,7 +274,6 @@ class DBIter: public Iterator {
  uint64_t max_skip_;
  uint64_t max_skippable_internal_keys_;
  uint64_t num_internal_keys_skipped_;
-  uint64_t version_number_;
  const Slice* iterate_upper_bound_;
  IterKey prefix_start_buf_;
  Slice prefix_start_key_;
@@ -1016,6 +1015,7 @@ void DBIter::Seek(const Slice& target) {
      if (valid_) {
        RecordTick(statistics_, NUMBER_DB_SEEK_FOUND);
        RecordTick(statistics_, ITER_BYTES_READ, key().size() + value().size());
+        PERF_COUNTER_ADD(iter_read_bytes, key().size() + value().size());
      }
    }
  } else {
@@ -1058,6 +1058,7 @@ void DBIter::SeekForPrev(const Slice& target) {
      if (valid_) {
        RecordTick(statistics_, NUMBER_DB_SEEK_FOUND);
        RecordTick(statistics_, ITER_BYTES_READ, key().size() + value().size());
+        PERF_COUNTER_ADD(iter_read_bytes, key().size() + value().size());
      }
    }
  } else {
@@ -1096,6 +1097,7 @@ void DBIter::SeekToFirst() {
      if (valid_) {
        RecordTick(statistics_, NUMBER_DB_SEEK_FOUND);
        RecordTick(statistics_, ITER_BYTES_READ, key().size() + value().size());
+        PERF_COUNTER_ADD(iter_read_bytes, key().size() + value().size());
      }
    }
  } else {
@@ -1143,6 +1145,7 @@ void DBIter::SeekToLast() {
    if (valid_) {
      RecordTick(statistics_, NUMBER_DB_SEEK_FOUND);
      RecordTick(statistics_, ITER_BYTES_READ, key().size() + value().size());
+      PERF_COUNTER_ADD(iter_read_bytes, key().size() + value().size());
    }
  }
  if (valid_ && prefix_extractor_ && prefix_same_as_start_) {
@@ -1157,18 +1160,15 @@ Iterator* NewDBIterator(Env* env, const ReadOptions& read_options,
                        const Comparator* user_key_comparator,
                        InternalIterator* internal_iter,
                        const SequenceNumber& sequence,
-                        uint64_t max_sequential_skip_in_iterations,
-                        uint64_t version_number) {
-  DBIter* db_iter = new DBIter(
-      env, read_options, cf_options, user_key_comparator, internal_iter,
-      sequence, false, max_sequential_skip_in_iterations, version_number);
+                        uint64_t max_sequential_skip_in_iterations) {
+  DBIter* db_iter = new DBIter(env, read_options, cf_options,
+                               user_key_comparator, internal_iter, sequence,
+                               false, max_sequential_skip_in_iterations);
  return db_iter;
 }

 ArenaWrappedDBIter::~ArenaWrappedDBIter() { db_iter_->~DBIter(); }

-void ArenaWrappedDBIter::SetDBIter(DBIter* iter) { db_iter_ = iter; }
-
 RangeDelAggregator* ArenaWrappedDBIter::GetRangeDelAggregator() {
  return db_iter_->GetRangeDelAggregator();
 }
@@ -1193,26 +1193,67 @@ inline Slice ArenaWrappedDBIter::value() const { return db_iter_->value(); }
 inline Status ArenaWrappedDBIter::status() const { return db_iter_->status(); }
 inline Status ArenaWrappedDBIter::GetProperty(std::string prop_name,
                                              std::string* prop) {
+  if (prop_name == "rocksdb.iterator.super-version-number") {
+    // First try to pass the value returned from inner iterator.
+    if (!db_iter_->GetProperty(prop_name, prop).ok()) {
+      *prop = ToString(sv_number_);
+    }
+    return Status::OK();
+  }
  return db_iter_->GetProperty(prop_name, prop);
 }
-void ArenaWrappedDBIter::RegisterCleanup(CleanupFunction function, void* arg1,
-                                         void* arg2) {
-  db_iter_->RegisterCleanup(function, arg1, arg2);
+
+void ArenaWrappedDBIter::Init(Env* env, const ReadOptions& read_options,
+                              const ImmutableCFOptions& cf_options,
+                              const SequenceNumber& sequence,
+                              uint64_t max_sequential_skip_in_iteration,
+                              uint64_t version_number) {
+  auto mem = arena_.AllocateAligned(sizeof(DBIter));
+  db_iter_ = new (mem)
+      DBIter(env, read_options, cf_options, cf_options.user_comparator, nullptr,
+             sequence, true, max_sequential_skip_in_iteration);
+  sv_number_ = version_number;
+}
+
+Status ArenaWrappedDBIter::Refresh() {
+  if (cfd_ == nullptr || db_impl_ == nullptr) {
+    return Status::NotSupported("Creating renew iterator is not allowed.");
+  }
+  assert(db_iter_ != nullptr);
+  SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
+  uint64_t cur_sv_number = cfd_->GetSuperVersionNumber();
+  if (sv_number_ != cur_sv_number) {
+    Env* env = db_iter_->env();
+    db_iter_->~DBIter();
+    arena_.~Arena();
+    new (&arena_) Arena();
+
+    SuperVersion* sv = cfd_->GetReferencedSuperVersion(db_impl_->mutex());
+    Init(env, read_options_, *(cfd_->ioptions()), latest_seq,
+         sv->mutable_cf_options.max_sequential_skip_in_iterations,
+         cur_sv_number);
+
+    InternalIterator* internal_iter = db_impl_->NewInternalIterator(
+        read_options_, cfd_, sv, &arena_, db_iter_->GetRangeDelAggregator());
+    SetIterUnderDBIter(internal_iter);
+  } else {
+    db_iter_->set_sequence(latest_seq);
+    db_iter_->set_valid(false);
+  }
+  return Status::OK();
 }

 ArenaWrappedDBIter* NewArenaWrappedDbIterator(
    Env* env, const ReadOptions& read_options,
-    const ImmutableCFOptions& cf_options, const Comparator* user_key_comparator,
-    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,
-    uint64_t version_number) {
+    const ImmutableCFOptions& cf_options, const SequenceNumber& sequence,
+    uint64_t max_sequential_skip_in_iterations, uint64_t version_number,
+    DBImpl* db_impl, ColumnFamilyData* cfd) {
  ArenaWrappedDBIter* iter = new ArenaWrappedDBIter();
-  Arena* arena = iter->GetArena();
-  auto mem = arena->AllocateAligned(sizeof(DBIter));
-  DBIter* db_iter = new (mem)
-      DBIter(env, read_options, cf_options, user_key_comparator, nullptr,
-             sequence, true, max_sequential_skip_in_iterations, version_number);
-
-  iter->SetDBIter(db_iter);
+  iter->Init(env, read_options, cf_options, sequence,
+             max_sequential_skip_in_iterations, version_number);
+  if (db_impl != nullptr && cfd != nullptr) {
+    iter->StoreRefreshInfo(read_options, db_impl, cfd);
+  }

  return iter;
 }
@@ -10,6 +10,7 @@
 #pragma once
 #include <stdint.h>
 #include <string>
+#include "db/db_impl.h"
 #include "db/dbformat.h"
 #include "db/range_del_aggregator.h"
 #include "options/cf_options.h"
@@ -32,8 +33,7 @@ extern Iterator* NewDBIterator(Env* env, const ReadOptions& read_options,
                               const Comparator* user_key_comparator,
                               InternalIterator* internal_iter,
                               const SequenceNumber& sequence,
-                               uint64_t max_sequential_skip_in_iterations,
-                               uint64_t version_number);
+                               uint64_t max_sequential_skip_in_iterations);

 // A wrapper iterator which wraps DB Iterator and the arena, with which the DB
 // iterator is supposed be allocated. This class is used as an entry point of
@@ -49,10 +49,6 @@ class ArenaWrappedDBIter : public Iterator {
  virtual Arena* GetArena() { return &arena_; }
  virtual RangeDelAggregator* GetRangeDelAggregator();

-  // Set the DB Iterator to be wrapped
-
-  virtual void SetDBIter(DBIter* iter);
-
  // Set the internal iterator wrapped inside the DB Iterator. Usually it is
  // a merging iterator.
  virtual void SetIterUnderDBIter(InternalIterator* iter);
@@ -66,20 +62,39 @@ class ArenaWrappedDBIter : public Iterator {
  virtual Slice key() const override;
  virtual Slice value() const override;
  virtual Status status() const override;
+  virtual Status Refresh() override;

-  void RegisterCleanup(CleanupFunction function, void* arg1, void* arg2);
  virtual Status GetProperty(std::string prop_name, std::string* prop) override;

+  void Init(Env* env, const ReadOptions& read_options,
+            const ImmutableCFOptions& cf_options,
+            const SequenceNumber& sequence,
+            uint64_t max_sequential_skip_in_iterations,
+            uint64_t version_number);
+
+  void StoreRefreshInfo(const ReadOptions& read_options, DBImpl* db_impl,
+                        ColumnFamilyData* cfd) {
+    read_options_ = read_options;
+    db_impl_ = db_impl;
+    cfd_ = cfd;
+  }
+
 private:
  DBIter* db_iter_;
  Arena arena_;
+  uint64_t sv_number_;
+  ColumnFamilyData* cfd_ = nullptr;
+  DBImpl* db_impl_ = nullptr;
+  ReadOptions read_options_;
 };

 // Generate the arena wrapped iterator class.
+// `db_impl` and `cfd` are used for reneweal. If left null, renewal will not
+// be supported.
 extern ArenaWrappedDBIter* NewArenaWrappedDbIterator(
    Env* env, const ReadOptions& read_options,
-    const ImmutableCFOptions& cf_options, const Comparator* user_key_comparator,
-    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,
-    uint64_t version_number);
+    const ImmutableCFOptions& cf_options, const SequenceNumber& sequence,
+    uint64_t max_sequential_skip_in_iterations, uint64_t version_number,
+    DBImpl* db_impl = nullptr, ColumnFamilyData* cfd = nullptr);

 }  // namespace rocksdb
@@ -193,7 +193,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
    ReadOptions ro;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -225,7 +225,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
    ReadOptions ro;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -251,7 +251,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -283,7 +283,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -318,7 +318,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(!db_iter->Valid());
@@ -347,7 +347,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      7, options.max_sequential_skip_in_iterations, 0));
+                      7, options.max_sequential_skip_in_iterations));

    SetPerfLevel(kEnableCount);
    ASSERT_TRUE(GetPerfLevel() == kEnableCount);
@@ -384,7 +384,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      4, options.max_sequential_skip_in_iterations, 0));
+                      4, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -409,7 +409,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(!db_iter->Valid());
@@ -431,7 +431,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -466,7 +466,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      7, options.max_sequential_skip_in_iterations, 0));
+                      7, options.max_sequential_skip_in_iterations));

    SetPerfLevel(kEnableCount);
    ASSERT_TRUE(GetPerfLevel() == kEnableCount);
@@ -495,7 +495,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
    ReadOptions ro;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -537,7 +537,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
    ReadOptions ro;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      2, options.max_sequential_skip_in_iterations, 0));
+                      2, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "b");
@@ -568,7 +568,7 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
    ReadOptions ro;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "c");
@@ -597,7 +597,7 @@ TEST_F(DBIteratorTest, DBIteratorEmpty) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      0, options.max_sequential_skip_in_iterations, 0));
+                      0, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(!db_iter->Valid());
  }
@@ -608,7 +608,7 @@ TEST_F(DBIteratorTest, DBIteratorEmpty) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      0, options.max_sequential_skip_in_iterations, 0));
+                      0, options.max_sequential_skip_in_iterations));
    db_iter->SeekToFirst();
    ASSERT_TRUE(!db_iter->Valid());
  }
@@ -630,7 +630,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkipCountSkips) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 2, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 2, options.max_sequential_skip_in_iterations));
  db_iter->SeekToLast();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "c");
@@ -673,7 +673,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
      options.statistics = rocksdb::CreateDBStatistics();
      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, i + 2,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));
      db_iter->SeekToLast();
      ASSERT_TRUE(db_iter->Valid());

@@ -708,7 +708,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {

      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, i + 2,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));
      db_iter->SeekToLast();
      ASSERT_TRUE(db_iter->Valid());

@@ -736,7 +736,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {

      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, 202,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));
      db_iter->SeekToLast();
      ASSERT_TRUE(db_iter->Valid());

@@ -768,7 +768,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
      internal_iter->Finish();
      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, i,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));
      db_iter->SeekToLast();
      ASSERT_TRUE(!db_iter->Valid());

@@ -784,7 +784,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
    internal_iter->Finish();
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      200, options.max_sequential_skip_in_iterations, 0));
+                      200, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "c");
@@ -818,7 +818,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {

      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, i + 2,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));
      db_iter->SeekToLast();
      ASSERT_TRUE(db_iter->Valid());

@@ -852,7 +852,7 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {

      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, i + 2,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));
      db_iter->SeekToLast();
      ASSERT_TRUE(db_iter->Valid());

@@ -900,7 +900,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 0;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -946,7 +946,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 2;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -990,7 +990,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 2;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -1028,7 +1028,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 2;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -1063,7 +1063,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 2;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -1093,7 +1093,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 2;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -1130,7 +1130,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
    ro.max_skippable_internal_keys = 2;
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToFirst();
    ASSERT_TRUE(db_iter->Valid());
@@ -1167,7 +1167,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
      ro.max_skippable_internal_keys = i;
      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, 2 * i + 1,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));

      db_iter->SeekToFirst();
      ASSERT_TRUE(db_iter->Valid());
@@ -1220,7 +1220,7 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
      ro.max_skippable_internal_keys = i;
      std::unique_ptr<Iterator> db_iter(NewDBIterator(
          env_, ro, cf_options, BytewiseComparator(), internal_iter, 2 * i + 1,
-          options.max_sequential_skip_in_iterations, 0));
+          options.max_sequential_skip_in_iterations));

      db_iter->SeekToFirst();
      ASSERT_TRUE(db_iter->Valid());
@@ -1258,7 +1258,7 @@ TEST_F(DBIteratorTest, DBIterator1) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 1, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 1, options.max_sequential_skip_in_iterations));
  db_iter->SeekToFirst();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1285,7 +1285,7 @@ TEST_F(DBIteratorTest, DBIterator2) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 0, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 0, options.max_sequential_skip_in_iterations));
  db_iter->SeekToFirst();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1309,7 +1309,7 @@ TEST_F(DBIteratorTest, DBIterator3) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 2, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 2, options.max_sequential_skip_in_iterations));
  db_iter->SeekToFirst();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1333,7 +1333,7 @@ TEST_F(DBIteratorTest, DBIterator4) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 4, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 4, options.max_sequential_skip_in_iterations));
  db_iter->SeekToFirst();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1365,7 +1365,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      0, options.max_sequential_skip_in_iterations, 0));
+                      0, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1387,7 +1387,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      1, options.max_sequential_skip_in_iterations, 0));
+                      1, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1409,7 +1409,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      2, options.max_sequential_skip_in_iterations, 0));
+                      2, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1431,7 +1431,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      3, options.max_sequential_skip_in_iterations, 0));
+                      3, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1453,7 +1453,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      4, options.max_sequential_skip_in_iterations, 0));
+                      4, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1475,7 +1475,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      5, options.max_sequential_skip_in_iterations, 0));
+                      5, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1497,7 +1497,7 @@ TEST_F(DBIteratorTest, DBIterator5) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      6, options.max_sequential_skip_in_iterations, 0));
+                      6, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1517,7 +1517,7 @@ TEST_F(DBIteratorTest, DBIterator5) {
    internal_iter->Finish();
    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      10, options.max_sequential_skip_in_iterations, 0));
+                      10, options.max_sequential_skip_in_iterations));
    db_iter->Seek("b");
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "b");
@@ -1546,7 +1546,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      0, options.max_sequential_skip_in_iterations, 0));
+                      0, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1568,7 +1568,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      1, options.max_sequential_skip_in_iterations, 0));
+                      1, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1590,7 +1590,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      2, options.max_sequential_skip_in_iterations, 0));
+                      2, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1612,7 +1612,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      3, options.max_sequential_skip_in_iterations, 0));
+                      3, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(!db_iter->Valid());
  }
@@ -1630,7 +1630,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      4, options.max_sequential_skip_in_iterations, 0));
+                      4, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1652,7 +1652,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      5, options.max_sequential_skip_in_iterations, 0));
+                      5, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1674,7 +1674,7 @@ TEST_F(DBIteratorTest, DBIterator6) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      6, options.max_sequential_skip_in_iterations, 0));
+                      6, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1715,7 +1715,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      0, options.max_sequential_skip_in_iterations, 0));
+                      0, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
    ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1749,7 +1749,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      2, options.max_sequential_skip_in_iterations, 0));
+                      2, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -1789,7 +1789,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      4, options.max_sequential_skip_in_iterations, 0));
+                      4, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -1829,7 +1829,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      5, options.max_sequential_skip_in_iterations, 0));
+                      5, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -1874,7 +1874,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      6, options.max_sequential_skip_in_iterations, 0));
+                      6, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -1920,7 +1920,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      7, options.max_sequential_skip_in_iterations, 0));
+                      7, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -1960,7 +1960,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      9, options.max_sequential_skip_in_iterations, 0));
+                      9, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -2006,7 +2006,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      13, options.max_sequential_skip_in_iterations, 0));
+                      13, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -2053,7 +2053,7 @@ TEST_F(DBIteratorTest, DBIterator7) {

    std::unique_ptr<Iterator> db_iter(
        NewDBIterator(env_, ro, cf_options, BytewiseComparator(), internal_iter,
-                      14, options.max_sequential_skip_in_iterations, 0));
+                      14, options.max_sequential_skip_in_iterations));
    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());

@@ -2083,7 +2083,7 @@ TEST_F(DBIteratorTest, DBIterator8) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 10, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 10, options.max_sequential_skip_in_iterations));
  db_iter->SeekToLast();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "b");
@@ -2113,7 +2113,7 @@ TEST_F(DBIteratorTest, DBIterator9) {

    std::unique_ptr<Iterator> db_iter(NewDBIterator(
        env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-        internal_iter, 10, options.max_sequential_skip_in_iterations, 0));
+        internal_iter, 10, options.max_sequential_skip_in_iterations));

    db_iter->SeekToLast();
    ASSERT_TRUE(db_iter->Valid());
@@ -2179,7 +2179,7 @@ TEST_F(DBIteratorTest, DBIterator10) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 10, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 10, options.max_sequential_skip_in_iterations));

  db_iter->Seek("c");
  ASSERT_TRUE(db_iter->Valid());
@@ -2218,7 +2218,7 @@ TEST_F(DBIteratorTest, SeekToLastOccurrenceSeq0) {

  std::unique_ptr<Iterator> db_iter(
      NewDBIterator(env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-                    internal_iter, 10, 0 /* force seek */, 0));
+                    internal_iter, 10, 0 /* force seek */));
  db_iter->SeekToFirst();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -2246,7 +2246,7 @@ TEST_F(DBIteratorTest, DBIterator11) {

  std::unique_ptr<Iterator> db_iter(NewDBIterator(
      env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-      internal_iter, 1, options.max_sequential_skip_in_iterations, 0));
+      internal_iter, 1, options.max_sequential_skip_in_iterations));
  db_iter->SeekToFirst();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -2272,7 +2272,7 @@ TEST_F(DBIteratorTest, DBIterator12) {

  std::unique_ptr<Iterator> db_iter(
      NewDBIterator(env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-                    internal_iter, 10, 0, 0));
+                    internal_iter, 10, 0));
  db_iter->SeekToLast();
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "c");
@@ -2309,7 +2309,7 @@ TEST_F(DBIteratorTest, DBIterator13) {

  std::unique_ptr<Iterator> db_iter(
      NewDBIterator(env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-                    internal_iter, 2, 3, 0));
+                    internal_iter, 2, 3));
  db_iter->Seek("b");
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), key);
@@ -2337,7 +2337,7 @@ TEST_F(DBIteratorTest, DBIterator14) {

  std::unique_ptr<Iterator> db_iter(
      NewDBIterator(env_, ro, ImmutableCFOptions(options), BytewiseComparator(),
-                    internal_iter, 4, 1, 0));
+                    internal_iter, 4, 1));
  db_iter->Seek("b");
  ASSERT_TRUE(db_iter->Valid());
  ASSERT_EQ(db_iter->key().ToString(), "b");
@@ -2376,7 +2376,7 @@ class DBIterWithMergeIterTest : public testing::Test {
    db_iter_.reset(NewDBIterator(env_, ro_, ImmutableCFOptions(options_),
                                 BytewiseComparator(), merge_iter,
                                 8 /* read data earlier than seqId 8 */,
-                                 3 /* max iterators before reseek */, 0));
+                                 3 /* max iterators before reseek */));
  }

  Env* env_;
@@ -1719,12 +1719,15 @@ TEST_F(DBIteratorTest, IteratorWithLocalStatistics) {

  std::vector<port::Thread> threads;
  std::function<void()> reader_func_next = [&]() {
+    SetPerfLevel(kEnableCount);
+    get_perf_context()->Reset();
    Iterator* iter = db_->NewIterator(ReadOptions());

    iter->SeekToFirst();
    // Seek will bump ITER_BYTES_READ
-    total_bytes += iter->key().size();
-    total_bytes += iter->value().size();
+    uint64_t bytes = 0;
+    bytes += iter->key().size();
+    bytes += iter->value().size();
    while (true) {
      iter->Next();
      total_next++;
@@ -1733,20 +1736,25 @@ TEST_F(DBIteratorTest, IteratorWithLocalStatistics) {
        break;
      }
      total_next_found++;
-      total_bytes += iter->key().size();
-      total_bytes += iter->value().size();
+      bytes += iter->key().size();
+      bytes += iter->value().size();
    }

    delete iter;
+    ASSERT_EQ(bytes, get_perf_context()->iter_read_bytes);
+    SetPerfLevel(kDisable);
+    total_bytes += bytes;
  };

  std::function<void()> reader_func_prev = [&]() {
+    SetPerfLevel(kEnableCount);
    Iterator* iter = db_->NewIterator(ReadOptions());

    iter->SeekToLast();
    // Seek will bump ITER_BYTES_READ
-    total_bytes += iter->key().size();
-    total_bytes += iter->value().size();
+    uint64_t bytes = 0;
+    bytes += iter->key().size();
+    bytes += iter->value().size();
    while (true) {
      iter->Prev();
      total_prev++;
@@ -1755,11 +1763,14 @@ TEST_F(DBIteratorTest, IteratorWithLocalStatistics) {
        break;
      }
      total_prev_found++;
-      total_bytes += iter->key().size();
-      total_bytes += iter->value().size();
+      bytes += iter->key().size();
+      bytes += iter->value().size();
    }

    delete iter;
+    ASSERT_EQ(bytes, get_perf_context()->iter_read_bytes);
+    SetPerfLevel(kDisable);
+    total_bytes += bytes;
  };

  for (int i = 0; i < 10; i++) {
@@ -1909,6 +1920,65 @@ TEST_F(DBIteratorTest, DBIteratorSkipRecentDuplicatesTest) {
                 NUMBER_OF_RESEEKS_IN_ITERATION));
 }

+TEST_F(DBIteratorTest, Refresh) {
+  ASSERT_OK(Put("x", "y"));
+
+  std::unique_ptr<Iterator> iter(db_->NewIterator(ReadOptions()));
+  iter->Seek(Slice("a"));
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("x")), 0);
+  iter->Next();
+  ASSERT_FALSE(iter->Valid());
+
+  ASSERT_OK(Put("c", "d"));
+
+  iter->Seek(Slice("a"));
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("x")), 0);
+  iter->Next();
+  ASSERT_FALSE(iter->Valid());
+
+  iter->Refresh();
+
+  iter->Seek(Slice("a"));
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("c")), 0);
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("x")), 0);
+  iter->Next();
+  ASSERT_FALSE(iter->Valid());
+
+  dbfull()->Flush(FlushOptions());
+
+  ASSERT_OK(Put("m", "n"));
+
+  iter->Seek(Slice("a"));
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("c")), 0);
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("x")), 0);
+  iter->Next();
+  ASSERT_FALSE(iter->Valid());
+
+  iter->Refresh();
+
+  iter->Seek(Slice("a"));
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("c")), 0);
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("m")), 0);
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ(iter->key().compare(Slice("x")), 0);
+  iter->Next();
+  ASSERT_FALSE(iter->Valid());
+
+  iter.reset();
+}
+
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -894,6 +894,74 @@ TEST_F(DBRangeDelTest, MemtableBloomFilter) {
  }
 }

+TEST_F(DBRangeDelTest, CompactionTreatsSplitInputLevelDeletionAtomically) {
+  // make sure compaction treats files containing a split range deletion in the
+  // input level as an atomic unit. I.e., compacting any input-level file(s)
+  // containing a portion of the range deletion causes all other input-level
+  // files containing portions of that same range deletion to be included in the
+  // compaction.
+  const int kNumFilesPerLevel = 4, kValueBytes = 4 << 10;
+  Options options = CurrentOptions();
+  options.compression = kNoCompression;
+  options.level0_file_num_compaction_trigger = kNumFilesPerLevel;
+  options.memtable_factory.reset(
+      new SpecialSkipListFactory(2 /* num_entries_flush */));
+  options.target_file_size_base = kValueBytes;
+  // i == 0: CompactFiles
+  // i == 1: CompactRange
+  // i == 2: automatic compaction
+  for (int i = 0; i < 3; ++i) {
+    DestroyAndReopen(options);
+
+    ASSERT_OK(Put(Key(0), ""));
+    ASSERT_OK(db_->Flush(FlushOptions()));
+    MoveFilesToLevel(2);
+    ASSERT_EQ(1, NumTableFilesAtLevel(2));
+
+    // snapshot protects range tombstone from dropping due to becoming obsolete.
+    const Snapshot* snapshot = db_->GetSnapshot();
+    db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), Key(0),
+                     Key(2 * kNumFilesPerLevel));
+
+    Random rnd(301);
+    std::string value = RandomString(&rnd, kValueBytes);
+    for (int j = 0; j < kNumFilesPerLevel; ++j) {
+      // give files overlapping key-ranges to prevent trivial move
+      ASSERT_OK(Put(Key(j), value));
+      ASSERT_OK(Put(Key(2 * kNumFilesPerLevel - 1 - j), value));
+      if (j > 0) {
+        dbfull()->TEST_WaitForFlushMemTable();
+        ASSERT_EQ(j, NumTableFilesAtLevel(0));
+      }
+    }
+    // put extra key to trigger final flush
+    ASSERT_OK(Put("", ""));
+    dbfull()->TEST_WaitForFlushMemTable();
+    dbfull()->TEST_WaitForCompact();
+    ASSERT_EQ(0, NumTableFilesAtLevel(0));
+    ASSERT_EQ(kNumFilesPerLevel, NumTableFilesAtLevel(1));
+
+    ColumnFamilyMetaData meta;
+    db_->GetColumnFamilyMetaData(&meta);
+    if (i == 0) {
+      ASSERT_OK(db_->CompactFiles(
+          CompactionOptions(), {meta.levels[1].files[0].name}, 2 /* level */));
+    } else if (i == 1) {
+      auto begin_str = Key(0), end_str = Key(1);
+      Slice begin = begin_str, end = end_str;
+      ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &begin, &end));
+    } else if (i == 2) {
+      ASSERT_OK(db_->SetOptions(db_->DefaultColumnFamily(),
+                                {{"max_bytes_for_level_base", "10000"}}));
+      dbfull()->TEST_WaitForCompact();
+    }
+    ASSERT_EQ(0, NumTableFilesAtLevel(1));
+    ASSERT_GT(NumTableFilesAtLevel(2), 0);
+
+    db_->ReleaseSnapshot(snapshot);
+  }
+}
+
 TEST_F(DBRangeDelTest, UnorderedTombstones) {
  // Regression test for #2752. Range delete tombstones between
  // different snapshot stripes are not stored in order, so the first
@@ -23,6 +23,7 @@
 #include <alloca.h>
 #endif

+#include "cache/lru_cache.h"
 #include "db/db_impl.h"
 #include "db/db_test_util.h"
 #include "db/dbformat.h"
@@ -2234,6 +2235,10 @@ class ModelDB : public DB {
    return Status::NotSupported("Not implemented.");
  }

+  virtual Status VerifyChecksum() override {
+    return Status::NotSupported("Not implemented.");
+  }
+
  using DB::GetPropertiesOfAllTables;
  virtual Status GetPropertiesOfAllTables(
      ColumnFamilyHandle* column_family,
@@ -2886,20 +2891,23 @@ TEST_F(DBTest, FIFOCompactionWithTTLAndVariousTableFormatsTest) {
  ASSERT_TRUE(TryReopen(options).IsNotSupported());
 }

-TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
+TEST_F(DBTest, FIFOCompactionWithTTLTest) {
  Options options;
  options.compaction_style = kCompactionStyleFIFO;
  options.write_buffer_size = 10 << 10;  // 10KB
  options.arena_block_size = 4096;
  options.compression = kNoCompression;
  options.create_if_missing = true;
+  env_->time_elapse_only_sleep_ = false;
+  options.env = env_;

  // Test to make sure that all files with expired ttl are deleted on next
  // manual compaction.
  {
+    env_->addon_time_.store(0);
    options.compaction_options_fifo.max_table_files_size = 150 << 10;  // 150KB
    options.compaction_options_fifo.allow_compaction = false;
-    options.compaction_options_fifo.ttl = 600;  // seconds
+    options.compaction_options_fifo.ttl = 1 * 60 * 60 ;  // 1 hour
    options = CurrentOptions(options);
    DestroyAndReopen(options);

@@ -2910,19 +2918,21 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 10);

-    // sleep for 5 seconds
-    env_->SleepForMicroseconds(5 * 1000 * 1000);
+    // Sleep for 2 hours -- which is much greater than TTL.
+    // Note: Couldn't use SleepForMicroseconds because it takes an int instead
+    // of uint64_t. Hence used addon_time_ directly.
+    // env_->SleepForMicroseconds(2 * 60 * 60 * 1000 * 1000);
+    env_->addon_time_.fetch_add(2 * 60 * 60);
+
+    // Since no flushes and compactions have run, the db should still be in
+    // the same state even after considerable time has passed.
    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 10);

-    // change ttl to 1 sec. So all files should be deleted on next compaction.
-    options.compaction_options_fifo.ttl = 1;
-    Reopen(options);
-
    dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
    ASSERT_EQ(NumTableFilesAtLevel(0), 0);
  }
@@ -2932,7 +2942,7 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
  {
    options.compaction_options_fifo.max_table_files_size = 150 << 10;  // 150KB
    options.compaction_options_fifo.allow_compaction = false;
-    options.compaction_options_fifo.ttl = 5;  // seconds
+    options.compaction_options_fifo.ttl = 1 * 60 * 60;  // 1 hour
    options = CurrentOptions(options);
    DestroyAndReopen(options);

@@ -2943,11 +2953,13 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 10);

-    env_->SleepForMicroseconds(6 * 1000 * 1000);
+    // Sleep for 2 hours -- which is much greater than TTL.
+    env_->addon_time_.fetch_add(2 * 60 * 60);
+    // Just to make sure that we are in the same state even after sleeping.
    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 10);

@@ -2969,10 +2981,10 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
  // Test that shows the fall back to size-based FIFO compaction if TTL-based
  // deletion doesn't move the total size to be less than max_table_files_size.
  {
-    options.write_buffer_size = 110 << 10;                             // 10KB
+    options.write_buffer_size = 10 << 10;                              // 10KB
    options.compaction_options_fifo.max_table_files_size = 150 << 10;  // 150KB
    options.compaction_options_fifo.allow_compaction = false;
-    options.compaction_options_fifo.ttl = 5;  // seconds
+    options.compaction_options_fifo.ttl =  1 * 60 * 60;  // 1 hour
    options = CurrentOptions(options);
    DestroyAndReopen(options);

@@ -2983,11 +2995,13 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 3);

-    env_->SleepForMicroseconds(6 * 1000 * 1000);
+    // Sleep for 2 hours -- which is much greater than TTL.
+    env_->addon_time_.fetch_add(2 * 60 * 60);
+    // Just to make sure that we are in the same state even after sleeping.
    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 3);

@@ -2996,8 +3010,8 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    // Size limit is still guaranteed.
    ASSERT_LE(SizeAtLevel(0),
              options.compaction_options_fifo.max_table_files_size);
@@ -3007,7 +3021,7 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
  {
    options.compaction_options_fifo.max_table_files_size = 150 << 10;  // 150KB
    options.compaction_options_fifo.allow_compaction = true;
-    options.compaction_options_fifo.ttl = 5;  // seconds
+    options.compaction_options_fifo.ttl = 1 * 60 * 60;  // 1 hour
    options.level0_file_num_compaction_trigger = 6;
    options = CurrentOptions(options);
    DestroyAndReopen(options);
@@ -3019,15 +3033,16 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
    // With Intra-L0 compaction, out of 10 files, 6 files will be compacted to 1
    // (due to level0_file_num_compaction_trigger = 6).
    // So total files = 1 + remaining 4 = 5.
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 5);

-    // Sleep for a little over ttl time.
-    env_->SleepForMicroseconds(6 * 1000 * 1000);
+    // Sleep for 2 hours -- which is much greater than TTL.
+    env_->addon_time_.fetch_add(2 * 60 * 60);
+    // Just to make sure that we are in the same state even after sleeping.
    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 5);

@@ -3037,8 +3052,8 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    ASSERT_EQ(NumTableFilesAtLevel(0), 5);
    ASSERT_LE(SizeAtLevel(0),
              options.compaction_options_fifo.max_table_files_size);
@@ -3050,7 +3065,7 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
    options.write_buffer_size = 20 << 10;                               // 20K
    options.compaction_options_fifo.max_table_files_size = 1500 << 10;  // 1.5MB
    options.compaction_options_fifo.allow_compaction = true;
-    options.compaction_options_fifo.ttl = 60 * 60;  // 1 hour
+    options.compaction_options_fifo.ttl = 1 * 60 * 60;  // 1 hour
    options.level0_file_num_compaction_trigger = 6;
    options = CurrentOptions(options);
    DestroyAndReopen(options);
@@ -3062,8 +3077,8 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());
    // It should be compacted to 10 files.
    ASSERT_EQ(NumTableFilesAtLevel(0), 10);

@@ -3073,8 +3088,8 @@ TEST_F(DBTest, DISABLED_FIFOCompactionWithTTLTest) {
        ASSERT_OK(Put(ToString(i * 20 + j + 2000), RandomString(&rnd, 980)));
      }
      Flush();
+      ASSERT_OK(dbfull()->TEST_WaitForCompact());
    }
-    ASSERT_OK(dbfull()->TEST_WaitForCompact());

    // It should be compacted to no more than 20 files.
    ASSERT_GT(NumTableFilesAtLevel(0), 10);
@@ -5360,6 +5375,36 @@ TEST_F(DBTest, RowCache) {
  ASSERT_EQ(TestGetTickerCount(options, ROW_CACHE_HIT), 1);
  ASSERT_EQ(TestGetTickerCount(options, ROW_CACHE_MISS), 1);
 }
+
+TEST_F(DBTest, PinnableSliceAndRowCache) {
+  Options options = CurrentOptions();
+  options.statistics = rocksdb::CreateDBStatistics();
+  options.row_cache = NewLRUCache(8192);
+  DestroyAndReopen(options);
+
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Flush());
+
+  ASSERT_EQ(Get("foo"), "bar");
+  ASSERT_EQ(
+      reinterpret_cast<LRUCache*>(options.row_cache.get())->TEST_GetLRUSize(),
+      1);
+
+  {
+    PinnableSlice pin_slice;
+    ASSERT_EQ(Get("foo", &pin_slice), Status::OK());
+    ASSERT_EQ(pin_slice.ToString(), "bar");
+    // Entry is already in cache, lookup will remove the element from lru
+    ASSERT_EQ(
+        reinterpret_cast<LRUCache*>(options.row_cache.get())->TEST_GetLRUSize(),
+        0);
+  }
+  // After PinnableSlice destruction element is added back in LRU
+  ASSERT_EQ(
+      reinterpret_cast<LRUCache*>(options.row_cache.get())->TEST_GetLRUSize(),
+      1);
+}
+
 #endif  // ROCKSDB_LITE

 TEST_F(DBTest, DeletingOldWalAfterDrop) {
@@ -2236,6 +2236,7 @@ TEST_F(DBTest2, LowPriWrite) {
  ASSERT_EQ(1, rate_limit_count.load());
 }

+#ifndef ROCKSDB_LITE
 TEST_F(DBTest2, RateLimitedCompactionReads) {
  // compaction input has 512KB data
  const int kNumKeysPerFile = 128;
@@ -2281,12 +2282,15 @@ TEST_F(DBTest2, RateLimitedCompactionReads) {
    // chose 1MB as the upper bound on the total bytes read.
    size_t rate_limited_bytes =
        options.rate_limiter->GetTotalBytesThrough(Env::IO_LOW);
-    ASSERT_GE(
-        rate_limited_bytes,
-        static_cast<size_t>(kNumKeysPerFile * kBytesPerKey * kNumL0Files));
+    // Include the explict prefetch of the footer in direct I/O case.
+    size_t direct_io_extra = use_direct_io ? 512 * 1024 : 0;
+    ASSERT_GE(rate_limited_bytes,
+              static_cast<size_t>(kNumKeysPerFile * kBytesPerKey * kNumL0Files +
+                                  direct_io_extra));
    ASSERT_LT(
        rate_limited_bytes,
-        static_cast<size_t>(2 * kNumKeysPerFile * kBytesPerKey * kNumL0Files));
+        static_cast<size_t>(2 * kNumKeysPerFile * kBytesPerKey * kNumL0Files +
+                            direct_io_extra));

    Iterator* iter = db_->NewIterator(ReadOptions());
    for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
@@ -2299,7 +2303,28 @@ TEST_F(DBTest2, RateLimitedCompactionReads) {
                  options.rate_limiter->GetTotalBytesThrough(Env::IO_LOW)));
  }
 }
+#endif  // ROCKSDB_LITE

+// Make sure DB can be reopen with reduced number of levels, given no file
+// is on levels higher than the new num_levels.
+TEST_F(DBTest2, ReduceLevel) {
+  Options options;
+  options.disable_auto_compactions = true;
+  options.num_levels = 7;
+  Reopen(options);
+  Put("foo", "bar");
+  Flush();
+  MoveFilesToLevel(6);
+  ASSERT_EQ("0,0,0,0,0,0,1", FilesPerLevel());
+  CompactRangeOptions compact_options;
+  compact_options.change_level = true;
+  compact_options.target_level = 1;
+  dbfull()->CompactRange(compact_options, nullptr, nullptr);
+  ASSERT_EQ("0,1", FilesPerLevel());
+  options.num_levels = 3;
+  Reopen(options);
+  ASSERT_EQ("0,1", FilesPerLevel());
+}
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -42,13 +42,24 @@ SpecialEnv::SpecialEnv(Env* base)
  non_writable_count_ = 0;
  table_write_callback_ = nullptr;
 }
-
+#ifndef ROCKSDB_LITE
 ROT13BlockCipher rot13Cipher_(16);
+#endif  // ROCKSDB_LITE

 DBTestBase::DBTestBase(const std::string path)
    : mem_env_(!getenv("MEM_ENV") ? nullptr : new MockEnv(Env::Default())),
-      encrypted_env_(!getenv("ENCRYPTED_ENV") ? nullptr : NewEncryptedEnv(mem_env_ ? mem_env_ : Env::Default(), new CTREncryptionProvider(rot13Cipher_))),
-      env_(new SpecialEnv(encrypted_env_ ? encrypted_env_ : (mem_env_ ? mem_env_ : Env::Default()))),
+#ifndef ROCKSDB_LITE
+      encrypted_env_(
+          !getenv("ENCRYPTED_ENV")
+              ? nullptr
+              : NewEncryptedEnv(mem_env_ ? mem_env_ : Env::Default(),
+                                new CTREncryptionProvider(rot13Cipher_))),
+#else
+      encrypted_env_(nullptr),
+#endif  // ROCKSDB_LITE
+      env_(new SpecialEnv(encrypted_env_
+                              ? encrypted_env_
+                              : (mem_env_ ? mem_env_ : Env::Default()))),
      option_config_(kDefault) {
  env_->SetBackgroundThreads(1, Env::LOW);
  env_->SetBackgroundThreads(1, Env::HIGH);
@@ -686,6 +697,13 @@ std::string DBTestBase::Get(int cf, const std::string& k,
  return result;
 }

+Status DBTestBase::Get(const std::string& k, PinnableSlice* v) {
+  ReadOptions options;
+  options.verify_checksums = true;
+  Status s = dbfull()->Get(options, dbfull()->DefaultColumnFamily(), k, v);
+  return s;
+}
+
 uint64_t DBTestBase::GetNumSnapshots() {
  uint64_t int_num;
  EXPECT_TRUE(dbfull()->GetIntProperty("rocksdb.num-snapshots", &int_num));
@@ -803,6 +803,8 @@ class DBTestBase : public testing::Test {
  std::string Get(int cf, const std::string& k,
                  const Snapshot* snapshot = nullptr);

+  Status Get(const std::string& k, PinnableSlice* v);
+
  uint64_t GetNumSnapshots();

  uint64_t GetTimeOldestSnapshots();
@@ -696,17 +696,12 @@ TEST_P(DBTestUniversalCompactionParallel, PickByFileNumberBug) {
    num_keys -= 100;
  }

-  // Wait for the 2nd background compaction process to start
-  TEST_SYNC_POINT("DBTestUniversalCompactionParallel::PickByFileNumberBug:0");
-  TEST_SYNC_POINT("DBTestUniversalCompactionParallel::PickByFileNumberBug:1");
-
-  // Hold the 1st and 2nd compaction from finishing
+  // Hold the 1st compaction from finishing
  TEST_SYNC_POINT("DBTestUniversalCompactionParallel::PickByFileNumberBug:2");
  dbfull()->TEST_WaitForCompact();

-  // Although 2 compaction threads started, the second one did not compact
-  // anything because the number of files not being compacted is less than
-  // level0_file_num_compaction_trigger
+  // There should only be one picked compaction as the score drops below one
+  // after the first one is picked.
  EXPECT_EQ(total_picked_compactions, 1);
  EXPECT_EQ(TotalTableFiles(), 4);

@@ -1370,6 +1365,140 @@ TEST_P(DBTestUniversalCompaction, UniversalCompactionSecondPathRatio) {
  Destroy(options);
 }

+TEST_P(DBTestUniversalCompaction, FullCompactionInBottomPriThreadPool) {
+  const int kNumFilesTrigger = 3;
+  Env::Default()->SetBackgroundThreads(1, Env::Priority::BOTTOM);
+  for (bool allow_ingest_behind : {false, true}) {
+    Options options = CurrentOptions();
+    options.allow_ingest_behind = allow_ingest_behind;
+    options.compaction_style = kCompactionStyleUniversal;
+    options.num_levels = num_levels_;
+    options.write_buffer_size = 100 << 10;     // 100KB
+    options.target_file_size_base = 32 << 10;  // 32KB
+    options.level0_file_num_compaction_trigger = kNumFilesTrigger;
+    // Trigger compaction if size amplification exceeds 110%
+    options.compaction_options_universal.max_size_amplification_percent = 110;
+    DestroyAndReopen(options);
+
+    int num_bottom_pri_compactions = 0;
+    SyncPoint::GetInstance()->SetCallBack(
+        "DBImpl::BGWorkBottomCompaction",
+        [&](void* arg) { ++num_bottom_pri_compactions; });
+    SyncPoint::GetInstance()->EnableProcessing();
+
+    Random rnd(301);
+    for (int num = 0; num < kNumFilesTrigger; num++) {
+      ASSERT_EQ(NumSortedRuns(), num);
+      int key_idx = 0;
+      GenerateNewFile(&rnd, &key_idx);
+    }
+    dbfull()->TEST_WaitForCompact();
+
+    if (allow_ingest_behind || num_levels_ > 1) {
+      // allow_ingest_behind increases number of levels while sanitizing.
+      ASSERT_EQ(1, num_bottom_pri_compactions);
+    } else {
+      // for single-level universal, everything's bottom level so nothing should
+      // be executed in bottom-pri thread pool.
+      ASSERT_EQ(0, num_bottom_pri_compactions);
+    }
+    // Verify that size amplification did occur
+    ASSERT_EQ(NumSortedRuns(), 1);
+    rocksdb::SyncPoint::GetInstance()->DisableProcessing();
+  }
+  Env::Default()->SetBackgroundThreads(0, Env::Priority::BOTTOM);
+}
+
+TEST_P(DBTestUniversalCompaction, ConcurrentBottomPriLowPriCompactions) {
+  if (num_levels_ == 1) {
+    // for single-level universal, everything's bottom level so nothing should
+    // be executed in bottom-pri thread pool.
+    return;
+  }
+  const int kNumFilesTrigger = 3;
+  Env::Default()->SetBackgroundThreads(1, Env::Priority::BOTTOM);
+  Options options = CurrentOptions();
+  options.compaction_style = kCompactionStyleUniversal;
+  options.num_levels = num_levels_;
+  options.write_buffer_size = 100 << 10;     // 100KB
+  options.target_file_size_base = 32 << 10;  // 32KB
+  options.level0_file_num_compaction_trigger = kNumFilesTrigger;
+  // Trigger compaction if size amplification exceeds 110%
+  options.compaction_options_universal.max_size_amplification_percent = 110;
+  DestroyAndReopen(options);
+
+  rocksdb::SyncPoint::GetInstance()->LoadDependency(
+      {// wait for the full compaction to be picked before adding files intended
+       // for the second one.
+       {"DBImpl::BackgroundCompaction:ForwardToBottomPriPool",
+        "DBTestUniversalCompaction:ConcurrentBottomPriLowPriCompactions:0"},
+       // the full (bottom-pri) compaction waits until a partial (low-pri)
+       // compaction has started to verify they can run in parallel.
+       {"DBImpl::BackgroundCompaction:NonTrivial",
+        "DBImpl::BGWorkBottomCompaction"}});
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  Random rnd(301);
+  for (int i = 0; i < 2; ++i) {
+    for (int num = 0; num < kNumFilesTrigger; num++) {
+      int key_idx = 0;
+      GenerateNewFile(&rnd, &key_idx, true /* no_wait */);
+      // use no_wait above because that one waits for flush and compaction. We
+      // don't want to wait for compaction because the full compaction is
+      // intentionally blocked while more files are flushed.
+      dbfull()->TEST_WaitForFlushMemTable();
+    }
+    if (i == 0) {
+      TEST_SYNC_POINT(
+          "DBTestUniversalCompaction:ConcurrentBottomPriLowPriCompactions:0");
+    }
+  }
+  dbfull()->TEST_WaitForCompact();
+
+  // First compaction should output to bottom level. Second should output to L0
+  // since older L0 files pending compaction prevent it from being placed lower.
+  ASSERT_EQ(NumSortedRuns(), 2);
+  ASSERT_GT(NumTableFilesAtLevel(0), 0);
+  ASSERT_GT(NumTableFilesAtLevel(num_levels_ - 1), 0);
+  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
+  Env::Default()->SetBackgroundThreads(0, Env::Priority::BOTTOM);
+}
+
+TEST_P(DBTestUniversalCompaction, RecalculateScoreAfterPicking) {
+  // Regression test for extra compactions scheduled. Once enough compactions
+  // have been scheduled to bring the score below one, we should stop
+  // scheduling more; otherwise, other CFs/DBs may be delayed unnecessarily.
+  const int kNumFilesTrigger = 8;
+  Options options = CurrentOptions();
+  options.compaction_options_universal.max_merge_width = kNumFilesTrigger / 2;
+  options.compaction_options_universal.max_size_amplification_percent =
+      static_cast<unsigned int>(-1);
+  options.compaction_style = kCompactionStyleUniversal;
+  options.level0_file_num_compaction_trigger = kNumFilesTrigger;
+  options.num_levels = num_levels_;
+  options.write_buffer_size = 100 << 10;  // 100KB
+  Reopen(options);
+
+  std::atomic<int> num_compactions_attempted(0);
+  rocksdb::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::BackgroundCompaction:Start", [&](void* arg) {
+        ++num_compactions_attempted;
+      });
+  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
+
+  Random rnd(301);
+  for (int num = 0; num < kNumFilesTrigger; num++) {
+    ASSERT_EQ(NumSortedRuns(), num);
+    int key_idx = 0;
+    GenerateNewFile(&rnd, &key_idx);
+  }
+  dbfull()->TEST_WaitForCompact();
+  // Compacting the first four files was enough to bring the score below one so
+  // there's no need to schedule any more compactions.
+  ASSERT_EQ(1, num_compactions_attempted);
+  ASSERT_EQ(NumSortedRuns(), 5);
+}
+
 INSTANTIATE_TEST_CASE_P(UniversalCompactionNumLevels, DBTestUniversalCompaction,
                        ::testing::Combine(::testing::Values(1, 3, 5),
                                           ::testing::Bool()));
@@ -3,17 +3,12 @@
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).

-#include <atomic>
 #include <memory>
 #include <thread>
 #include <vector>
 #include "db/db_test_util.h"
 #include "db/write_batch_internal.h"
-#include "db/write_thread.h"
-#include "port/port.h"
 #include "port/stack_trace.h"
-#include "util/fault_injection_test_env.h"
-#include "util/string_util.h"
 #include "util/sync_point.h"

 namespace rocksdb {
@@ -23,9 +18,7 @@ class DBWriteTest : public DBTestBase, public testing::WithParamInterface<int> {
 public:
  DBWriteTest() : DBTestBase("/db_write_test") {}

-  Options GetOptions() { return DBTestBase::GetOptions(GetParam()); }
-
-  void Open() { DBTestBase::Reopen(GetOptions()); }
+  void Open() { DBTestBase::Reopen(GetOptions(GetParam())); }
 };

 // Sequence number should be return through input write batch.
@@ -74,47 +67,6 @@ TEST_P(DBWriteTest, ReturnSeuqneceNumberMultiThreaded) {
  }
 }

-TEST_P(DBWriteTest, IOErrorOnWALWritePropagateToWriteThreadFollower) {
-  constexpr int kNumThreads = 5;
-  std::unique_ptr<FaultInjectionTestEnv> mock_env(
-      new FaultInjectionTestEnv(Env::Default()));
-  Options options = GetOptions();
-  options.env = mock_env.get();
-  Reopen(options);
-  std::atomic<int> ready_count{0};
-  std::atomic<int> leader_count{0};
-  std::vector<port::Thread> threads;
-  mock_env->SetFilesystemActive(false);
-  // Wait until all threads linked to write threads, to make sure
-  // all threads join the same batch group.
-  SyncPoint::GetInstance()->SetCallBack(
-      "WriteThread::JoinBatchGroup:Wait", [&](void* arg) {
-        ready_count++;
-        auto* w = reinterpret_cast<WriteThread::Writer*>(arg);
-        if (w->state == WriteThread::STATE_GROUP_LEADER) {
-          leader_count++;
-          while (ready_count < kNumThreads) {
-            // busy waiting
-          }
-        }
-      });
-  SyncPoint::GetInstance()->EnableProcessing();
-  for (int i = 0; i < kNumThreads; i++) {
-    threads.push_back(port::Thread(
-        [&](int index) {
-          // All threads should fail.
-          ASSERT_FALSE(Put("key" + ToString(index), "value").ok());
-        },
-        i));
-  }
-  for (int i = 0; i < kNumThreads; i++) {
-    threads[i].join();
-  }
-  ASSERT_EQ(1, leader_count);
-  // Close before mock_env destruct.
-  Close();
-}
-
 INSTANTIATE_TEST_CASE_P(DBWriteTestInstance, DBWriteTest,
                        testing::Values(DBTestBase::kDefault,
                                        DBTestBase::kConcurrentWALWrites,
@@ -84,6 +84,12 @@ struct ParsedInternalKey {
  ParsedInternalKey(const Slice& u, const SequenceNumber& seq, ValueType t)
      : user_key(u), sequence(seq), type(t) { }
  std::string DebugString(bool hex = false) const;
+
+  void clear() {
+    user_key.clear();
+    sequence = 0;
+    type = kTypeDeletion;
+  }
 };

 // Return the length of the encoding of "key".
@@ -151,6 +157,9 @@ class InternalKeyComparator : public Comparator {

  int Compare(const InternalKey& a, const InternalKey& b) const;
  int Compare(const ParsedInternalKey& a, const ParsedInternalKey& b) const;
+  virtual const Comparator* GetRootComparator() const override {
+    return user_comparator_->GetRootComparator();
+  }
 };

 // Modules in this directory should keep internal keys wrapped inside
@@ -14,20 +14,18 @@ namespace experimental {

 Status SuggestCompactRange(DB* db, ColumnFamilyHandle* column_family,
                           const Slice* begin, const Slice* end) {
-  auto dbimpl = dynamic_cast<DBImpl*>(db);
-  if (dbimpl == nullptr) {
-    return Status::InvalidArgument("Didn't recognize DB object");
+  if (db == nullptr) {
+    return Status::InvalidArgument("DB is empty");
  }

-  return dbimpl->SuggestCompactRange(column_family, begin, end);
+  return db->SuggestCompactRange(column_family, begin, end);
 }

 Status PromoteL0(DB* db, ColumnFamilyHandle* column_family, int target_level) {
-  auto dbimpl = dynamic_cast<DBImpl*>(db);
-  if (dbimpl == nullptr) {
+  if (db == nullptr) {
    return Status::InvalidArgument("Didn't recognize DB object");
  }
-  return dbimpl->PromoteL0(column_family, target_level);
+  return db->PromoteL0(column_family, target_level);
 }

 #else  // ROCKSDB_LITE
@@ -18,6 +18,33 @@

 namespace rocksdb {

+MergeHelper::MergeHelper(Env* env, const Comparator* user_comparator,
+                         const MergeOperator* user_merge_operator,
+                         const CompactionFilter* compaction_filter,
+                         Logger* logger, bool assert_valid_internal_key,
+                         SequenceNumber latest_snapshot, int level,
+                         Statistics* stats,
+                         const std::atomic<bool>* shutting_down)
+    : env_(env),
+      user_comparator_(user_comparator),
+      user_merge_operator_(user_merge_operator),
+      compaction_filter_(compaction_filter),
+      shutting_down_(shutting_down),
+      logger_(logger),
+      assert_valid_internal_key_(assert_valid_internal_key),
+      allow_single_operand_(false),
+      latest_snapshot_(latest_snapshot),
+      level_(level),
+      keys_(),
+      filter_timer_(env_),
+      total_filter_time_(0U),
+      stats_(stats) {
+  assert(user_comparator_ != nullptr);
+  if (user_merge_operator_) {
+    allow_single_operand_ = user_merge_operator_->AllowSingleOperand();
+  }
+}
+
 Status MergeHelper::TimedFullMerge(const MergeOperator* merge_operator,
                                   const Slice& key, const Slice* value,
                                   const std::vector<Slice>& operands,
@@ -201,12 +228,11 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
          ikey.sequence <= latest_snapshot_
              ? CompactionFilter::Decision::kKeep
              : FilterMerge(orig_ikey.user_key, value_slice);
-      if (range_del_agg != nullptr &&
-
+      if (filter != CompactionFilter::Decision::kRemoveAndSkipUntil &&
+          range_del_agg != nullptr &&
          range_del_agg->ShouldDelete(
              iter->key(),
-              RangeDelAggregator::RangePositioningMode::kForwardTraversal) &&
-          filter != CompactionFilter::Decision::kRemoveAndSkipUntil) {
+              RangeDelAggregator::RangePositioningMode::kForwardTraversal)) {
        filter = CompactionFilter::Decision::kRemove;
      }
      if (filter == CompactionFilter::Decision::kKeep ||
@@ -289,7 +315,8 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
    // Attempt to use the user's associative merge function to
    // merge the stacked merge operands into a single operand.
    s = Status::MergeInProgress();
-    if (merge_context_.GetNumOperands() >= 2) {
+    if (merge_context_.GetNumOperands() >= 2 ||
+        (allow_single_operand_ && merge_context_.GetNumOperands() == 1)) {
      bool merge_success = false;
      std::string merge_result;
      {
@@ -34,22 +34,7 @@ class MergeHelper {
              const CompactionFilter* compaction_filter, Logger* logger,
              bool assert_valid_internal_key, SequenceNumber latest_snapshot,
              int level = 0, Statistics* stats = nullptr,
-              const std::atomic<bool>* shutting_down = nullptr)
-      : env_(env),
-        user_comparator_(user_comparator),
-        user_merge_operator_(user_merge_operator),
-        compaction_filter_(compaction_filter),
-        shutting_down_(shutting_down),
-        logger_(logger),
-        assert_valid_internal_key_(assert_valid_internal_key),
-        latest_snapshot_(latest_snapshot),
-        level_(level),
-        keys_(),
-        filter_timer_(env_),
-        total_filter_time_(0U),
-        stats_(stats) {
-    assert(user_comparator_ != nullptr);
-  }
+              const std::atomic<bool>* shutting_down = nullptr);

  // Wrapper around MergeOperator::FullMergeV2() that records perf statistics.
  // Result of merge will be written to result if status returned is OK.
@@ -158,6 +143,7 @@ class MergeHelper {
  const std::atomic<bool>* shutting_down_;
  Logger* logger_;
  bool assert_valid_internal_key_; // enforce no internal key corruption?
+  bool allow_single_operand_;
  SequenceNumber latest_snapshot_;
  int level_;

@@ -357,7 +357,8 @@ Status RangeDelAggregator::AddTombstone(RangeTombstone tombstone) {
      ++new_range_dels_iter;
    }
  } else {
-    tombstone_map.emplace(tombstone.start_key_, std::move(tombstone));
+    auto start_key = tombstone.start_key_;
+    tombstone_map.emplace(start_key, std::move(tombstone));
  }
  return Status::OK();
 }
@@ -176,6 +176,7 @@ class Repairer {
      status = db_impl->NewDB();
      delete db_impl;
    }
+
    if (status.ok()) {
      // Recover using the fresh manifest created by NewDB()
      status =
@@ -246,9 +247,21 @@ class Repairer {
  Status FindFiles() {
    std::vector<std::string> filenames;
    bool found_file = false;
+    std::vector<std::string> to_search_paths;
+
    for (size_t path_id = 0; path_id < db_options_.db_paths.size(); path_id++) {
+        to_search_paths.push_back(db_options_.db_paths[path_id].path);
+    }
+
+    // search wal_dir if user uses a customize wal_dir
+    if (!db_options_.wal_dir.empty() && 
+        db_options_.wal_dir != dbname_) {
+        to_search_paths.push_back(db_options_.wal_dir);
+    }
+
+    for (size_t path_id = 0; path_id < to_search_paths.size(); path_id++) {
      Status status =
-          env_->GetChildren(db_options_.db_paths[path_id].path, &filenames);
+          env_->GetChildren(to_search_paths[path_id], &filenames);
      if (!status.ok()) {
        return status;
      }
@@ -261,14 +274,12 @@ class Repairer {
      for (size_t i = 0; i < filenames.size(); i++) {
        if (ParseFileName(filenames[i], &number, &type)) {
          if (type == kDescriptorFile) {
-            assert(path_id == 0);
            manifests_.push_back(filenames[i]);
          } else {
            if (number + 1 > next_file_number_) {
              next_file_number_ = number + 1;
            }
            if (type == kLogFile) {
-              assert(path_id == 0);
              logs_.push_back(number);
            } else if (type == kTableFile) {
              table_fds_.emplace_back(number, static_cast<uint32_t>(path_id),
@@ -288,7 +299,8 @@ class Repairer {

  void ConvertLogFilesToTables() {
    for (size_t i = 0; i < logs_.size(); i++) {
-      std::string logname = LogFileName(dbname_, logs_[i]);
+      // we should use LogFileName(wal_dir, logs_[i]) here. user might uses wal_dir option.
+      std::string logname = LogFileName(db_options_.wal_dir, logs_[i]);
      Status status = ConvertLogToTable(logs_[i]);
      if (!status.ok()) {
        ROCKS_LOG_WARN(db_options_.info_log,
@@ -312,7 +324,7 @@ class Repairer {
    };

    // Open the log file
-    std::string logname = LogFileName(dbname_, log);
+    std::string logname = LogFileName(db_options_.wal_dir, log);
    unique_ptr<SequentialFile> lfile;
    Status status = env_->NewSequentialFile(
        logname, &lfile, env_->OptimizeForLogRead(env_options_));
@@ -174,6 +174,40 @@ TEST_F(RepairTest, UnflushedSst) {
  ASSERT_EQ(Get("key"), "val");
 }

+TEST_F(RepairTest, SeparateWalDir) {
+  do {
+    Options options = CurrentOptions();
+    DestroyAndReopen(options);
+    Put("key", "val");
+    Put("foo", "bar");
+    VectorLogPtr wal_files;
+    ASSERT_OK(dbfull()->GetSortedWalFiles(wal_files));
+    ASSERT_EQ(wal_files.size(), 1);
+    uint64_t total_ssts_size;
+    GetAllSSTFiles(&total_ssts_size);
+    ASSERT_EQ(total_ssts_size, 0);
+    std::string manifest_path =
+      DescriptorFileName(dbname_, dbfull()->TEST_Current_Manifest_FileNo());
+
+    Close();
+    ASSERT_OK(env_->FileExists(manifest_path));
+    ASSERT_OK(env_->DeleteFile(manifest_path));
+    ASSERT_OK(RepairDB(dbname_, options));
+
+    // make sure that all WALs are converted to SSTables.
+    options.wal_dir = "";
+
+    Reopen(options);
+    ASSERT_OK(dbfull()->GetSortedWalFiles(wal_files));
+    ASSERT_EQ(wal_files.size(), 0);
+    GetAllSSTFiles(&total_ssts_size);
+    ASSERT_GT(total_ssts_size, 0);
+    ASSERT_EQ(Get("key"), "val");
+    ASSERT_EQ(Get("foo"), "bar");
+
+ } while(ChangeWalOptions());
+}
+
 TEST_F(RepairTest, RepairMultipleColumnFamilies) {
  // Verify repair logic associates SST files with their original column
  // families.
@@ -74,9 +74,11 @@ class SnapshotList {
    count_--;
  }

-  // retrieve all snapshot numbers. They are sorted in ascending order.
+  // retrieve all snapshot numbers up until max_seq. They are sorted in
+  // ascending order.
  std::vector<SequenceNumber> GetAll(
-      SequenceNumber* oldest_write_conflict_snapshot = nullptr) {
+      SequenceNumber* oldest_write_conflict_snapshot = nullptr,
+      const SequenceNumber& max_seq = kMaxSequenceNumber) const {
    std::vector<SequenceNumber> ret;

    if (oldest_write_conflict_snapshot != nullptr) {
@@ -86,8 +88,11 @@ class SnapshotList {
    if (empty()) {
      return ret;
    }
-    SnapshotImpl* s = &list_;
+    const SnapshotImpl* s = &list_;
    while (s->next_ != &list_) {
+      if (s->next_->number_ > max_seq) {
+        break;
+      }
      ret.push_back(s->next_->number_);

      if (oldest_write_conflict_snapshot != nullptr &&
@@ -106,10 +106,10 @@ Status TableCache::GetTableReader(
    }
    StopWatch sw(ioptions_.env, ioptions_.statistics, TABLE_OPEN_IO_MICROS);
    std::unique_ptr<RandomAccessFileReader> file_reader(
-        new RandomAccessFileReader(std::move(file), fname, ioptions_.env,
-                                   ioptions_.statistics, record_read_stats,
-                                   file_read_hist, ioptions_.rate_limiter,
-                                   for_compaction));
+        new RandomAccessFileReader(
+            std::move(file), fname, ioptions_.env,
+            record_read_stats ? ioptions_.statistics : nullptr, SST_READ_MICROS,
+            file_read_hist, ioptions_.rate_limiter, for_compaction));
    s = ioptions_.table_factory->NewTableReader(
        TableReaderOptions(ioptions_, env_options, internal_comparator,
                           skip_filters, level),
@@ -225,8 +225,7 @@ InternalIterator* TableCache::NewIterator(
  }
  InternalIterator* result = nullptr;
  if (s.ok()) {
-    result =
-      table_reader->NewIterator(options, arena, &icomparator, skip_filters);
+    result = table_reader->NewIterator(options, arena, skip_filters);
    if (create_new_table_reader) {
      assert(handle == nullptr);
      result->RegisterCleanup(&DeleteTableReader, table_reader, nullptr);
@@ -311,6 +310,7 @@ Status TableCache::Get(const ReadOptions& options,
 #ifndef ROCKSDB_LITE
  IterKey row_cache_key;
  std::string row_cache_entry_buffer;
+
  // Check row cache if enabled. Since row cache does not currently store
  // sequence numbers, we cannot use it if we need to fetch the sequence.
  if (ioptions_.row_cache && !get_context->NeedToReadSequence()) {
@@ -334,10 +334,26 @@ Status TableCache::Get(const ReadOptions& options,

    if (auto row_handle =
            ioptions_.row_cache->Lookup(row_cache_key.GetUserKey())) {
+      // Cleanable routine to release the cache entry
+      Cleanable value_pinner;
+      auto release_cache_entry_func = [](void* cache_to_clean,
+                                         void* cache_handle) {
+        ((Cache*)cache_to_clean)->Release((Cache::Handle*)cache_handle);
+      };
      auto found_row_cache_entry = static_cast<const std::string*>(
          ioptions_.row_cache->Value(row_handle));
-      replayGetContextLog(*found_row_cache_entry, user_key, get_context);
-      ioptions_.row_cache->Release(row_handle);
+      // If it comes here value is located on the cache.
+      // found_row_cache_entry points to the value on cache,
+      // and value_pinner has cleanup procedure for the cached entry.
+      // After replayGetContextLog() returns, get_context.pinnable_slice_
+      // will point to cache entry buffer (or a copy based on that) and
+      // cleanup routine under value_pinner will be delegated to
+      // get_context.pinnable_slice_. Cache entry is released when
+      // get_context.pinnable_slice_ is reset.
+      value_pinner.RegisterCleanup(release_cache_entry_func,
+                                   ioptions_.row_cache.get(), row_handle);
+      replayGetContextLog(*found_row_cache_entry, user_key, get_context,
+                          &value_pinner);
      RecordTick(ioptions_.statistics, ROW_CACHE_HIT);
      done = true;
    } else {
@@ -17,6 +17,7 @@
 #include <algorithm>
 #include <atomic>
 #include <functional>
+#include <map>
 #include <set>
 #include <thread>
 #include <unordered_map>
@@ -87,7 +88,16 @@ class VersionBuilder::Rep {
  Logger* info_log_;
  TableCache* table_cache_;
  VersionStorageInfo* base_vstorage_;
+  int num_levels_;
  LevelState* levels_;
+  // Store states of levels larger than num_levels_. We do this instead of
+  // storing them in levels_ to avoid regression in case there are no files
+  // on invalid levels. The version is not consistent if in the end the files
+  // on invalid levels don't cancel out.
+  std::map<int, std::unordered_set<uint64_t>> invalid_levels_;
+  // Whether there are invalid new files or invalid deletion on levels larger
+  // than num_levels_.
+  bool has_invalid_levels_;
  FileComparator level_zero_cmp_;
  FileComparator level_nonzero_cmp_;

@@ -97,8 +107,10 @@ class VersionBuilder::Rep {
      : env_options_(env_options),
        info_log_(info_log),
        table_cache_(table_cache),
-        base_vstorage_(base_vstorage) {
-    levels_ = new LevelState[base_vstorage_->num_levels()];
+        base_vstorage_(base_vstorage),
+        num_levels_(base_vstorage->num_levels()),
+        has_invalid_levels_(false) {
+    levels_ = new LevelState[num_levels_];
    level_zero_cmp_.sort_method = FileComparator::kLevel0;
    level_nonzero_cmp_.sort_method = FileComparator::kLevelNon0;
    level_nonzero_cmp_.internal_comparator =
@@ -106,7 +118,7 @@ class VersionBuilder::Rep {
  }

  ~Rep() {
-    for (int level = 0; level < base_vstorage_->num_levels(); level++) {
+    for (int level = 0; level < num_levels_; level++) {
      const auto& added = levels_[level].added_files;
      for (auto& pair : added) {
        UnrefFile(pair.second);
@@ -137,7 +149,7 @@ class VersionBuilder::Rep {
    }
 #endif
    // make sure the files are sorted correctly
-    for (int level = 0; level < vstorage->num_levels(); level++) {
+    for (int level = 0; level < num_levels_; level++) {
      auto& level_files = vstorage->LevelFiles(level);
      for (size_t i = 1; i < level_files.size(); i++) {
        auto f1 = level_files[i - 1];
@@ -196,7 +208,7 @@ class VersionBuilder::Rep {
 #endif
    // a file to be deleted better exist in the previous version
    bool found = false;
-    for (int l = 0; !found && l < base_vstorage_->num_levels(); l++) {
+    for (int l = 0; !found && l < num_levels_; l++) {
      const std::vector<FileMetaData*>& base_files =
          base_vstorage_->LevelFiles(l);
      for (size_t i = 0; i < base_files.size(); i++) {
@@ -210,7 +222,7 @@ class VersionBuilder::Rep {
    // if the file did not exist in the previous version, then it
    // is possibly moved from lower level to higher level in current
    // version
-    for (int l = level + 1; !found && l < base_vstorage_->num_levels(); l++) {
+    for (int l = level + 1; !found && l < num_levels_; l++) {
      auto& level_added = levels_[l].added_files;
      auto got = level_added.find(number);
      if (got != level_added.end()) {
@@ -233,6 +245,19 @@ class VersionBuilder::Rep {
    }
  }

+  bool CheckConsistencyForNumLevels() {
+    // Make sure there are no files on or beyond num_levels().
+    if (has_invalid_levels_) {
+      return false;
+    }
+    for (auto& level : invalid_levels_) {
+      if (level.second.size() > 0) {
+        return false;
+      }
+    }
+    return true;
+  }
+
  // Apply all of the edits in *edit to the current state.
  void Apply(VersionEdit* edit) {
    CheckConsistency(base_vstorage_);
@@ -242,26 +267,45 @@ class VersionBuilder::Rep {
    for (const auto& del_file : del) {
      const auto level = del_file.first;
      const auto number = del_file.second;
-      levels_[level].deleted_files.insert(number);
-      CheckConsistencyForDeletes(edit, number, level);
+      if (level < num_levels_) {
+        levels_[level].deleted_files.insert(number);
+        CheckConsistencyForDeletes(edit, number, level);

-      auto exising = levels_[level].added_files.find(number);
-      if (exising != levels_[level].added_files.end()) {
-        UnrefFile(exising->second);
-        levels_[level].added_files.erase(number);
+        auto exising = levels_[level].added_files.find(number);
+        if (exising != levels_[level].added_files.end()) {
+          UnrefFile(exising->second);
+          levels_[level].added_files.erase(number);
+        }
+      } else {
+        if (invalid_levels_[level].count(number) > 0) {
+          invalid_levels_[level].erase(number);
+        } else {
+          // Deleting an non-existing file on invalid level.
+          has_invalid_levels_ = true;
+        }
      }
    }

    // Add new files
    for (const auto& new_file : edit->GetNewFiles()) {
      const int level = new_file.first;
-      FileMetaData* f = new FileMetaData(new_file.second);
-      f->refs = 1;
+      if (level < num_levels_) {
+        FileMetaData* f = new FileMetaData(new_file.second);
+        f->refs = 1;

-      assert(levels_[level].added_files.find(f->fd.GetNumber()) ==
-             levels_[level].added_files.end());
-      levels_[level].deleted_files.erase(f->fd.GetNumber());
-      levels_[level].added_files[f->fd.GetNumber()] = f;
+        assert(levels_[level].added_files.find(f->fd.GetNumber()) ==
+               levels_[level].added_files.end());
+        levels_[level].deleted_files.erase(f->fd.GetNumber());
+        levels_[level].added_files[f->fd.GetNumber()] = f;
+      } else {
+        uint64_t number = new_file.second.fd.GetNumber();
+        if (invalid_levels_[level].count(number) == 0) {
+          invalid_levels_[level].insert(number);
+        } else {
+          // Creating an already existing file on invalid level.
+          has_invalid_levels_ = true;
+        }
+      }
    }
  }

@@ -270,7 +314,7 @@ class VersionBuilder::Rep {
    CheckConsistency(base_vstorage_);
    CheckConsistency(vstorage);

-    for (int level = 0; level < base_vstorage_->num_levels(); level++) {
+    for (int level = 0; level < num_levels_; level++) {
      const auto& cmp = (level == 0) ? level_zero_cmp_ : level_nonzero_cmp_;
      // Merge the set of added files with the set of pre-existing files.
      // Drop any deleted files.  Store the result in *v.
@@ -325,7 +369,7 @@ class VersionBuilder::Rep {
    assert(table_cache_ != nullptr);
    // <file metadata, level>
    std::vector<std::pair<FileMetaData*, int>> files_meta;
-    for (int level = 0; level < base_vstorage_->num_levels(); level++) {
+    for (int level = 0; level < num_levels_; level++) {
      for (auto& file_meta_pair : levels_[level].added_files) {
        auto* file_meta = file_meta_pair.second;
        assert(!file_meta->table_reader_handle);
@@ -386,24 +430,35 @@ VersionBuilder::VersionBuilder(const EnvOptions& env_options,
                               VersionStorageInfo* base_vstorage,
                               Logger* info_log)
    : rep_(new Rep(env_options, info_log, table_cache, base_vstorage)) {}
+
 VersionBuilder::~VersionBuilder() { delete rep_; }
+
 void VersionBuilder::CheckConsistency(VersionStorageInfo* vstorage) {
  rep_->CheckConsistency(vstorage);
 }
+
 void VersionBuilder::CheckConsistencyForDeletes(VersionEdit* edit,
                                                uint64_t number, int level) {
  rep_->CheckConsistencyForDeletes(edit, number, level);
 }
+
+bool VersionBuilder::CheckConsistencyForNumLevels() {
+  return rep_->CheckConsistencyForNumLevels();
+}
+
 void VersionBuilder::Apply(VersionEdit* edit) { rep_->Apply(edit); }
+
 void VersionBuilder::SaveTo(VersionStorageInfo* vstorage) {
  rep_->SaveTo(vstorage);
 }
+
 void VersionBuilder::LoadTableHandlers(
    InternalStats* internal_stats, int max_threads,
    bool prefetch_index_and_filter_in_cache) {
  rep_->LoadTableHandlers(internal_stats, max_threads,
                          prefetch_index_and_filter_in_cache);
 }
+
 void VersionBuilder::MaybeAddFile(VersionStorageInfo* vstorage, int level,
                                  FileMetaData* f) {
  rep_->MaybeAddFile(vstorage, level, f);
@@ -29,6 +29,7 @@ class VersionBuilder {
  void CheckConsistency(VersionStorageInfo* vstorage);
  void CheckConsistencyForDeletes(VersionEdit* edit, uint64_t number,
                                  int level);
+  bool CheckConsistencyForNumLevels();
  void Apply(VersionEdit* edit);
  void SaveTo(VersionStorageInfo* vstorage);
  void LoadTableHandlers(InternalStats* internal_stats, int max_threads,
@@ -328,10 +328,6 @@ Version::~Version() {
      assert(f->refs > 0);
      f->refs--;
      if (f->refs <= 0) {
-        if (f->table_reader_handle) {
-          cfd_->table_cache()->EraseHandle(f->fd, f->table_reader_handle);
-          f->table_reader_handle = nullptr;
-        }
        vset_->obsolete_files_.push_back(f);
      }
    }
@@ -1231,6 +1227,14 @@ int VersionStorageInfo::MaxInputLevel() const {
  return 0;
 }

+int VersionStorageInfo::MaxOutputLevel(bool allow_ingest_behind) const {
+  if (allow_ingest_behind) {
+    assert(num_levels() > 1);
+    return num_levels() - 2;
+  }
+  return num_levels() - 1;
+}
+
 void VersionStorageInfo::EstimateCompactionBytesNeeded(
    const MutableCFOptions& mutable_cf_options) {
  // Only implemented for level-based compaction
@@ -2331,10 +2335,14 @@ void CloseTables(void* ptr, size_t) {
 VersionSet::~VersionSet() {
  // we need to delete column_family_set_ because its destructor depends on
  // VersionSet
-  column_family_set_->get_table_cache()->ApplyToAllCacheEntries(&CloseTables,
-                                                                false);
+  Cache* table_cache = column_family_set_->get_table_cache();
+  table_cache->ApplyToAllCacheEntries(&CloseTables, false /* thread_safe */);
  column_family_set_.reset();
  for (auto file : obsolete_files_) {
+    if (file->table_reader_handle) {
+      table_cache->Release(file->table_reader_handle);
+      TableCache::Evict(table_cache, file->fd.GetNumber());
+    }
    delete file;
  }
  obsolete_files_.clear();
@@ -2834,11 +2842,6 @@ Status VersionSet::Recover(
        cfd = column_family_set_->GetColumnFamily(edit.column_family_);
        // this should never happen since cf_in_builders is true
        assert(cfd != nullptr);
-        if (edit.max_level_ >= cfd->current()->storage_info()->num_levels()) {
-          s = Status::InvalidArgument(
-              "db has more levels than options.num_levels");
-          break;
-        }

        // if it is not column family add or column family drop,
        // then it's a file add/delete, which should be forwarded
@@ -2922,6 +2925,18 @@ Status VersionSet::Recover(
        list_of_not_found);
  }

+  if (s.ok()) {
+    for (auto cfd : *column_family_set_) {
+      assert(builders.count(cfd->GetID()) > 0);
+      auto* builder = builders[cfd->GetID()]->version_builder();
+      if (!builder->CheckConsistencyForNumLevels()) {
+        s = Status::InvalidArgument(
+            "db has more levels than options.num_levels");
+        break;
+      }
+    }
+  }
+
  if (s.ok()) {
    for (auto cfd : *column_family_set_) {
      if (cfd->IsDropped()) {
@@ -147,6 +147,7 @@ class VersionStorageInfo {
  }

  int MaxInputLevel() const;
+  int MaxOutputLevel(bool allow_ingest_behind) const;

  // Return level number that has idx'th highest score
  int CompactionScoreLevel(int idx) const { return compaction_level_[idx]; }
@@ -26,6 +26,7 @@
 #include "rocksdb/env.h"
 #include "rocksdb/options.h"
 #include "rocksdb/write_batch.h"
+#include "util/cast_util.h"
 #include "util/coding.h"
 #include "util/file_reader_writer.h"
 #include "util/filename.h"
@@ -273,8 +274,8 @@ namespace {
 struct CompareLogByPointer {
  bool operator()(const std::unique_ptr<LogFile>& a,
                  const std::unique_ptr<LogFile>& b) {
-    LogFileImpl* a_impl = dynamic_cast<LogFileImpl*>(a.get());
-    LogFileImpl* b_impl = dynamic_cast<LogFileImpl*>(b.get());
+    LogFileImpl* a_impl = static_cast_with_check<LogFileImpl, LogFile>(a.get());
+    LogFileImpl* b_impl = static_cast_with_check<LogFileImpl, LogFile>(b.get());
    return *a_impl < *b_impl;
  }
 };
@@ -1303,6 +1303,7 @@ Status WriteBatchInternal::InsertInto(WriteThread::WriteGroup& write_group,
      continue;
    }
    SetSequence(w->batch, inserter.sequence());
+    w->sequence = inserter.sequence();
    inserter.set_log_number_ref(w->log_ref);
    w->status = w->batch->Iterate(&inserter);
    if (!w->status.ok()) {
@@ -60,7 +60,7 @@ static std::string PrintContents(WriteBatch* b) {
    }
    for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
      ParsedInternalKey ikey;
-      memset((void*)&ikey, 0, sizeof(ikey));
+      ikey.clear();
      EXPECT_TRUE(ParseInternalKey(iter->key(), &ikey));
      switch (ikey.type) {
        case kTypeValue:
@@ -451,20 +451,20 @@ TEST_F(WriteBatchTest, DISABLED_ManyUpdates) {
    }
    virtual Status DeleteCF(uint32_t column_family_id,
                            const Slice& key) override {
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
      return Status::OK();
    }
    virtual Status SingleDeleteCF(uint32_t column_family_id,
                                  const Slice& key) override {
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
      return Status::OK();
    }
    virtual Status MergeCF(uint32_t column_family_id, const Slice& key,
                           const Slice& value) override {
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
      return Status::OK();
    }
-    virtual void LogData(const Slice& blob) override { EXPECT_TRUE(false); }
+    virtual void LogData(const Slice& blob) override { ADD_FAILURE(); }
    virtual bool Continue() override { return num_seen < kNumUpdates; }
  } handler;

@@ -502,20 +502,20 @@ TEST_F(WriteBatchTest, DISABLED_LargeKeyValue) {
    }
    virtual Status DeleteCF(uint32_t column_family_id,
                            const Slice& key) override {
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
      return Status::OK();
    }
    virtual Status SingleDeleteCF(uint32_t column_family_id,
                                  const Slice& key) override {
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
      return Status::OK();
    }
    virtual Status MergeCF(uint32_t column_family_id, const Slice& key,
                           const Slice& value) override {
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
      return Status::OK();
    }
-    virtual void LogData(const Slice& blob) override { EXPECT_TRUE(false); }
+    virtual void LogData(const Slice& blob) override { ADD_FAILURE(); }
    virtual bool Continue() override { return num_seen < 2; }
  } handler;

@@ -16,7 +16,6 @@
 #include "rocksdb/db.h"
 #include "rocksdb/write_batch.h"
 #include "port/port.h"
-#include "util/logging.h"
 #include "util/random.h"
 #include "util/sync_point.h"
 #include "util/testharness.h"
@@ -107,6 +106,10 @@ TEST_F(WriteCallbackTest, WriteWithCallbackTest) {
    std::vector<std::pair<string, string>> kvs_;
  };

+  // In each scenario we'll launch multiple threads to write.
+  // The size of each array equals to number of threads, and
+  // each boolean in it denote whether callback of corresponding
+  // thread should succeed or fail.
  std::vector<std::vector<WriteOP>> write_scenarios = {
      {true},
      {false},
@@ -134,11 +137,6 @@ TEST_F(WriteCallbackTest, WriteWithCallbackTest) {
              options.allow_concurrent_memtable_write = allow_parallel;
              options.enable_pipelined_write = enable_pipelined_write;
              options.concurrent_prepare = two_queues;
-              if (options.enable_pipelined_write &&
-                  options.concurrent_prepare) {
-                // This combination is not supported
-                continue;
-              }

              ReadOptions read_options;
              DB* db;
@@ -150,23 +148,37 @@ TEST_F(WriteCallbackTest, WriteWithCallbackTest) {
              db_impl = dynamic_cast<DBImpl*>(db);
              ASSERT_TRUE(db_impl);

-              std::atomic<uint64_t> threads_waiting(0);
+              // Writers that have called JoinBatchGroup.
+              std::atomic<uint64_t> threads_joining(0);
+              // Writers that have linked to the queue
+              std::atomic<uint64_t> threads_linked(0);
+              // Writers that pass WriteThread::JoinBatchGroup:Wait sync-point.
+              std::atomic<uint64_t> threads_verified(0);
+
              std::atomic<uint64_t> seq(db_impl->GetLatestSequenceNumber());
              ASSERT_EQ(db_impl->GetLatestSequenceNumber(), 0);

+              rocksdb::SyncPoint::GetInstance()->SetCallBack(
+                  "WriteThread::JoinBatchGroup:Start", [&](void*) {
+                    uint64_t cur_threads_joining = threads_joining.fetch_add(1);
+                    // Wait for the last joined writer to link to the queue.
+                    // In this way the writers link to the queue one by one.
+                    // This allows us to confidently detect the first writer
+                    // who increases threads_linked as the leader.
+                    while (threads_linked.load() < cur_threads_joining) {
+                    }
+                  });
+
+              // Verification once writers call JoinBatchGroup.
              rocksdb::SyncPoint::GetInstance()->SetCallBack(
                  "WriteThread::JoinBatchGroup:Wait", [&](void* arg) {
-                    uint64_t cur_threads_waiting = 0;
+                    uint64_t cur_threads_linked = threads_linked.fetch_add(1);
                    bool is_leader = false;
                    bool is_last = false;

                    // who am i
-                    do {
-                      cur_threads_waiting = threads_waiting.load();
-                      is_leader = (cur_threads_waiting == 0);
-                      is_last = (cur_threads_waiting == write_group.size() - 1);
-                    } while (!threads_waiting.compare_exchange_strong(
-                        cur_threads_waiting, cur_threads_waiting + 1));
+                    is_leader = (cur_threads_linked == 0);
+                    is_last = (cur_threads_linked == write_group.size() - 1);

                    // check my state
                    auto* writer = reinterpret_cast<WriteThread::Writer*>(arg);
@@ -190,8 +202,10 @@ TEST_F(WriteCallbackTest, WriteWithCallbackTest) {
                                  !write_group.back().callback_.should_fail_);
                    }

-                    // wait for friends
-                    while (threads_waiting.load() < write_group.size()) {
+                    threads_verified.fetch_add(1);
+                    // Wait here until all verification in this sync-point
+                    // callback finish for all writers.
+                    while (threads_verified.load() < write_group.size()) {
                    }
                  });

@@ -216,17 +230,20 @@ TEST_F(WriteCallbackTest, WriteWithCallbackTest) {

              std::atomic<uint32_t> thread_num(0);
              std::atomic<char> dummy_key(0);
+
+              // Each write thread create a random write batch and write to DB
+              // with a write callback.
              std::function<void()> write_with_callback_func = [&]() {
                uint32_t i = thread_num.fetch_add(1);
                Random rnd(i);

                // leaders gotta lead
-                while (i > 0 && threads_waiting.load() < 1) {
+                while (i > 0 && threads_verified.load() < 1) {
                }

                // loser has to lose
                while (i == write_group.size() - 1 &&
-                       threads_waiting.load() < write_group.size() - 1) {
+                       threads_verified.load() < write_group.size() - 1) {
                }

                auto& write_op = write_group.at(i);
@@ -236,11 +253,7 @@ TEST_F(WriteCallbackTest, WriteWithCallbackTest) {
                // insert some keys
                for (uint32_t j = 0; j < rnd.Next() % 50; j++) {
                  // grab unique key
-                  char my_key = 0;
-                  do {
-                    my_key = dummy_key.load();
-                  } while (
-                      !dummy_key.compare_exchange_strong(my_key, my_key + 1));
+                  char my_key = dummy_key.fetch_add(1);

                  string skey(5, my_key);
                  string sval(10, my_key);