fb internal: Should also use GCC 4.8.1 for CentOS 7

Flush before Fsync()/Sync()
Summary: Calling Fsync()/Sync() on a file should give the guarantee that whatever you written to the file is now persisted. This is currently not the case, since we might have some data left in application cache as we do Fsync()/Sync(). For example, BuildTable() calls Fsync() without the flush, assuming all sst data is now persisted, but it's actually not. This may result in big inconsistencies. Test Plan: no test Reviewers: sdong, dhruba, haobo, ljin, yhchiang Reviewed By: sdong CC: leveldb Differential Revision: https://reviews.facebook.net/D18159
2026-07-07 14:47:40 +08:00 · 2016-10-13 13:48:56 -07:00 · 2014-04-21 18:08:49 -07:00 · 2014-04-17 09:57:24 -07:00 · 2014-04-04 17:30:55 -07:00 · 2014-04-04 16:27:47 -07:00
208 changed files with 20398 additions and 5371 deletions
@@ -6,6 +6,5 @@
    "linters"
  ],
  "lint.engine" : "FacebookFbcodeLintEngine",
-  "lint.engine.single.linter" : "FbcodeCppLinter",
-  "lint.cpplint.prefix" : "linters"
+  "lint.engine.single.linter" : "FbcodeCppLinter"
 }
@@ -12,6 +12,11 @@ build_config.mk
 *_test
 *_bench
 *_stress
+*.out
+*.class
+*.jar
+*.*jnilib*
+*.d-e

 ldb
 manifest_dump
@@ -21,3 +26,6 @@ build_tools/VALGRIND_LOGS/
 coverage/COVERAGE_REPORT
 .gdbhistory
 .phutil_module_cache
+tags
+java/*.log
+java/include/org_rocksdb_*.h
@@ -10,6 +10,10 @@ the CLA and we can cross-check with your GitHub username.

 Complete your CLA here: <https://developers.facebook.com/opensource/cla>

+If you don't have a Facebook account, we can send you a PDF that you can
+sign offline. Send us an e-mail or create a new github issue to
+request the CLA in PDF format.
+
 ## License

 By contributing to RocksDB, you agree that your contributions will be
@@ -1,5 +1,38 @@
 # Rocksdb Change Log

+## Unreleased
+
+### Public API changes
+
+## 2.8.0 (04/04/2014)
+
+* Removed arena.h from public header files.
+* By default, checksums are verified on every read from database
+* Change default value of several options, including: paranoid_checks=true, max_open_files=5000, level0_slowdown_writes_trigger=20, level0_stop_writes_trigger=24, disable_seek_compaction=true, max_background_flushes=1 and allow_mmap_writes=false
+* Added is_manual_compaction to CompactionFilter::Context
+* Added "virtual void WaitForJoin()" in class Env. Default operation is no-op.
+* Removed BackupEngine::DeleteBackupsNewerThan() function
+* Added new option -- verify_checksums_in_compaction
+* Changed Options.prefix_extractor from raw pointer to shared_ptr (take ownership)
+  Changed HashSkipListRepFactory and HashLinkListRepFactory constructor to not take SliceTransform object (use Options.prefix_extractor implicitly)
+* Added Env::GetThreadPoolQueueLen(), which returns the waiting queue length of thread pools
+* Added a command "checkconsistency" in ldb tool, which checks
+  if file system state matches DB state (file existence and file sizes)
+* Separate options related to block based table to a new struct BlockBasedTableOptions
+* WriteBatch has a new function Count() to return total size in the batch, and Data() now returns a reference instead of a copy
+* Add more counters to perf context.
+* Supports several more DB properties: compaction-pending, background-errors and cur-size-active-mem-table.
+
+### New Features
+* If we find one truncated record at the end of the MANIFEST or WAL files,
+  we will ignore it. We assume that writers of these records were interrupted
+  and that we can safely ignore it.
+* A new SST format "PlainTable" is added, which is optimized for memory-only workloads. It can be created through NewPlainTableFactory() or NewTotalOrderPlainTableFactory().
+* A new mem table implementation hash linked list optimizing for the case that there are only few keys for each prefix, which can be created through NewHashLinkListRepFactory().
+* Merge operator supports a new function PartialMergeMulti() to allow users to do partial merges against multiple operands.
+* Now compaction filter has a V2 interface. It buffers the kv-pairs sharing the same key prefix, process them in batches, and return the batched results back to DB. The new interface uses a new structure CompactionFilterContext for the same purpose as CompactionFilter::Context in V1.
+* Geo-spatial support for locations and radial-search.
+
 ## 2.7.0 (01/28/2014)

 ### Public API changes
@@ -17,15 +17,42 @@ libraries. You are on your own.

 ## Supported platforms

-* **Linux**
+* **Linux - Ubuntu**
    * Upgrade your gcc to version at least 4.7 to get C++11 support.
-    * Install gflags. First, try: `sudo apt-get install libgflags-dev`.
+    * Install gflags. First, try: `sudo apt-get install libgflags-dev`
      If this doesn't work and you're using Ubuntu, here's a nice tutorial:
      (http://askubuntu.com/questions/312173/installing-gflags-12-04)
    * Install snappy. This is usually as easy as:
      `sudo apt-get install libsnappy-dev`.
    * Install zlib. Try: `sudo apt-get install zlib1g-dev`.
    * Install bzip2: `sudo apt-get install libbz2-dev`.
+* **Linux - CentOS**
+    * Upgrade your gcc to version at least 4.7 to get C++11 support:
+      `yum install gcc47-c++`
+    * Install gflags:
+
+              wget https://gflags.googlecode.com/files/gflags-2.0-no-svn-files.tar.gz
+              tar -xzvf gflags-2.0-no-svn-files.tar.gz
+              cd gflags-2.0
+              ./configure && make && sudo make install
+
+    * Install snappy:
+
+              wget https://snappy.googlecode.com/files/snappy-1.1.1.tar.gz
+              tar -xzvf snappy-1.1.1.tar.gz
+              cd snappy-1.1.1
+              ./configure && make && sudo make install
+
+    * Install zlib:
+
+              sudo yum install zlib
+              sudo yum install zlib-devel
+
+    * Install bzip2:
+
+              sudo yum install bzip2
+              sudo yum install bzip2-devel
+
 * **OS X**:
    * Install latest C++ compiler that supports C++ 11:
        * Update XCode:  run `xcode-select --install` (or install it from XCode App's settting).
@@ -40,11 +67,14 @@ libraries. You are on your own.
    * Please note that some of the optimizations/features are disabled in OSX.
    We did not run any production workloads on it.

+* **iOS**:
+  * Run: `TARGET_OS=IOS make static_lib`
+
 ## Compilation
-`make clean; make` will compile librocksdb.a (RocskDB static library) and all
+`make clean; make` will compile librocksdb.a (RocksDB static library) and all
 the unit tests. You can run all unit tests with `make check`.

-For shared library builds, exec `make librocksdb.so` instead.
+For shared library builds, exec `make shared_lib` instead.

 If you followed the above steps and your compile or unit tests fail,
 please submit an issue: (https://github.com/facebook/rocksdb/issues)
@@ -2,7 +2,7 @@ BSD License

 For rocksdb software

-Copyright (c) 2013, Facebook, Inc.
+Copyright (c) 2014, Facebook, Inc.
 All rights reserved.
 ---------------------------------------------------------------------

@@ -6,11 +6,16 @@
 INSTALL_PATH ?= $(CURDIR)

 #-----------------------------------------------
-# Uncomment exactly one of the lines labelled (A), (B), and (C) below
-# to switch between compilation modes.

-# OPT ?= -DNDEBUG     # (A) Production use (optimized mode)
+ifneq ($(MAKECMDGOALS),dbg)
 OPT += -O2 -fno-omit-frame-pointer -momit-leaf-frame-pointer
+else
+# intentionally left blank
+endif
+
+ifeq ($(MAKECMDGOALS),shared_lib)
+PLATFORM_SHARED_LDFLAGS=-fPIC
+endif
 #-----------------------------------------------

 # detect what platform we're building on
@@ -18,6 +23,14 @@ $(shell (export ROCKSDB_ROOT=$(CURDIR); $(CURDIR)/build_tools/build_detect_platf
 # this file is generated by the previous line to set build flags and sources
 include build_config.mk

+ifneq ($(PLATFORM), IOS)
+CFLAGS += -g
+CXXFLAGS += -g
+else
+# no debug info for IOS, that will make our library big
+OPT += -DNDEBUG
+endif
+
 # ASAN doesn't work well with jemalloc. If we're compiling with ASAN, we should use regular malloc.
 ifdef COMPILE_WITH_ASAN
 	# ASAN compile flags
@@ -31,9 +44,9 @@ else
 	PLATFORM_CCFLAGS += $(JEMALLOC_INCLUDE) -DHAVE_JEMALLOC
 endif

-WARNING_FLAGS = -Wall -Werror
-CFLAGS += -g $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CCFLAGS) $(OPT)
-CXXFLAGS += -g $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverloaded-virtual
+WARNING_FLAGS = -Wall -Werror -Wno-sign-compare
+CFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CCFLAGS) $(OPT)
+CXXFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverloaded-virtual

 LDFLAGS += $(PLATFORM_LDFLAGS)

@@ -50,12 +63,14 @@ VALGRIND_OPTS = --error-exitcode=$(VALGRIND_ERROR) --leak-check=full

 TESTS = \
 	db_test \
+	block_hash_index_test \
 	autovector_test \
 	table_properties_collector_test \
 	arena_test \
 	auto_roll_logger_test \
 	block_test \
 	bloom_test \
+	dynamic_bloom_test \
 	c_test \
 	cache_test \
 	coding_test \
@@ -74,6 +89,8 @@ TESTS = \
 	merge_test \
 	redis_test \
 	reduce_levels_test \
+	plain_table_db_test \
+	prefix_test \
 	simple_table_db_test \
 	skiplist_test \
 	stringappend_test \
@@ -83,21 +100,27 @@ TESTS = \
 	version_set_test \
 	write_batch_test\
 	deletefile_test \
-	table_test
+	table_test \
+	thread_local_test \
+        geodb_test

 TOOLS = \
        sst_dump \
+	db_sanity_test \
        db_stress \
        ldb \
 	db_repl_stress \
 	blob_store_bench

-PROGRAMS = db_bench signal_test $(TESTS) $(TOOLS)
+
+PROGRAMS = db_bench signal_test table_reader_bench $(TESTS) $(TOOLS)
 BENCHMARKS = db_bench_sqlite3 db_bench_tree_db table_reader_bench

 # The library name is configurable since we are maintaining libraries of both
 # debug/release mode.
-LIBNAME = librocksdb
+ifeq ($(LIBNAME),)
+        LIBNAME=librocksdb
+endif
 LIBRARY = ${LIBNAME}.a
 MEMENVLIBRARY = libmemenv.a

@@ -127,29 +150,36 @@ $(SHARED2): $(SHARED3)
 	ln -fs $(SHARED3) $(SHARED2)
 endif

-$(SHARED3): $(LIBOBJECTS)
-	$(CXX) $(PLATFORM_SHARED_LDFLAGS)$(SHARED2) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(LDFLAGS) $(SOURCES)-o $@
+$(SHARED3):
+	$(CXX) $(PLATFORM_SHARED_LDFLAGS)$(SHARED2) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(LDFLAGS) $(SOURCES) -o $@

 endif  # PLATFORM_SHARED_EXT

+.PHONY: blackbox_crash_test check clean coverage crash_test ldb_tests \
+	release tags valgrind_check whitebox_crash_test format static_lib shared_lib all \
+	dbg
+
 all: $(LIBRARY) $(PROGRAMS)

-.PHONY: blackbox_crash_test check clean coverage crash_test ldb_tests \
-	release tags valgrind_check whitebox_crash_test format shared_lib
+static_lib: $(LIBRARY)

-# Will also generate shared libraries. 
+shared_lib: $(SHARED)
+
+dbg: $(LIBRARY) $(PROGRAMS)
+
+# Will also generate shared libraries.
 release:
 	$(MAKE) clean
-	OPT=-DNDEBUG $(MAKE) all -j32
+	OPT="-DNDEBUG -O2" $(MAKE) all -j32

 coverage:
 	$(MAKE) clean
-	COVERAGEFLAGS="-fprofile-arcs -ftest-coverage" LDFLAGS+="-lgcov" $(MAKE) all check
+	COVERAGEFLAGS="-fprofile-arcs -ftest-coverage" LDFLAGS+="-lgcov" $(MAKE) all check -j32
 	(cd coverage; ./coverage_test.sh)
 	# Delete intermediate files
 	find . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm {} \;

-check: all $(PROGRAMS) $(TESTS) $(TOOLS)
+check: $(PROGRAMS) $(TESTS) $(TOOLS)
 	for t in $(TESTS); do echo "***** Running $$t"; ./$$t || exit 1; done
 	python tools/ldb_test.py

@@ -200,8 +230,6 @@ tags:
 format:
 	build_tools/format-diff.sh

-shared_lib: $(SHARED)
-
 # ---------------------------------------------------------------------------
 # 	Unit tests and tools
 # ---------------------------------------------------------------------------
@@ -212,9 +240,15 @@ $(LIBRARY): $(LIBOBJECTS)
 db_bench: db/db_bench.o $(LIBOBJECTS) $(TESTUTIL)
 	$(CXX) db/db_bench.o $(LIBOBJECTS) $(TESTUTIL) $(EXEC_LDFLAGS) -o $@  $(LDFLAGS) $(COVERAGEFLAGS)

+block_hash_index_test: table/block_hash_index_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	 $(CXX) table/block_hash_index_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+
 db_stress: tools/db_stress.o $(LIBOBJECTS) $(TESTUTIL)
 	$(CXX) tools/db_stress.o $(LIBOBJECTS) $(TESTUTIL) $(EXEC_LDFLAGS) -o $@  $(LDFLAGS) $(COVERAGEFLAGS)

+db_sanity_test: tools/db_sanity_test.o $(LIBOBJECTS) $(TESTUTIL)
+	$(CXX) tools/db_sanity_test.o $(LIBOBJECTS) $(TESTUTIL) $(EXEC_LDFLAGS) -o $@  $(LDFLAGS) $(COVERAGEFLAGS)
+
 db_repl_stress: tools/db_repl_stress.o $(LIBOBJECTS) $(TESTUTIL)
 	$(CXX) tools/db_repl_stress.o $(LIBOBJECTS) $(TESTUTIL) $(EXEC_LDFLAGS) -o $@  $(LDFLAGS) $(COVERAGEFLAGS)

@@ -242,6 +276,9 @@ table_properties_collector_test: db/table_properties_collector_test.o $(LIBOBJEC
 bloom_test: util/bloom_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/bloom_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

+dynamic_bloom_test: util/dynamic_bloom_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) util/dynamic_bloom_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+
 c_test: db/c_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/c_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

@@ -263,6 +300,9 @@ redis_test: utilities/redis/redis_lists_test.o $(LIBOBJECTS) $(TESTHARNESS)
 histogram_test: util/histogram_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/histogram_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o$@ $(LDFLAGS) $(COVERAGEFLAGS)

+thread_local_test: util/thread_local_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) util/thread_local_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+
 corruption_test: db/corruption_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/corruption_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

@@ -272,11 +312,17 @@ crc32c_test: util/crc32c_test.o $(LIBOBJECTS) $(TESTHARNESS)
 db_test: db/db_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/db_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

+log_write_bench: util/log_write_bench.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) util/log_write_bench.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS) -pg
+
+plain_table_db_test: db/plain_table_db_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) db/plain_table_db_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+
 simple_table_db_test: db/simple_table_db_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/simple_table_db_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

 table_reader_bench: table/table_reader_bench.o $(LIBOBJECTS) $(TESTHARNESS)
-	$(CXX) table/table_reader_bench.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+	$(CXX) table/table_reader_bench.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS) -pg

 perf_context_test: db/perf_context_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/perf_context_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS)
@@ -332,12 +378,15 @@ merge_test: db/merge_test.o $(LIBOBJECTS) $(TESTHARNESS)
 deletefile_test: db/deletefile_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/deletefile_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS)

+geodb_test: utilities/geodb/geodb_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) utilities/geodb/geodb_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+
 $(MEMENVLIBRARY) : $(MEMENVOBJECTS)
 	rm -f $@
 	$(AR) -rs $@ $(MEMENVOBJECTS)

-memenv_test : helpers/memenv/memenv_test.o $(MEMENVLIBRARY) $(LIBRARY) $(TESTHARNESS)
-	$(CXX) helpers/memenv/memenv_test.o $(MEMENVLIBRARY) $(LIBRARY) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+memenv_test : helpers/memenv/memenv_test.o $(MEMENVOBJECTS) $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) helpers/memenv/memenv_test.o $(MEMENVOBJECTS) $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

 manual_compaction_test: util/manual_compaction_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/manual_compaction_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
@@ -360,6 +409,32 @@ sst_dump: tools/sst_dump.o $(LIBOBJECTS)
 ldb: tools/ldb.o $(LIBOBJECTS)
 	$(CXX) tools/ldb.o $(LIBOBJECTS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

+# ---------------------------------------------------------------------------
+# Jni stuff
+# ---------------------------------------------------------------------------
+JNI_NATIVE_SOURCES = ./java/rocksjni/rocksjni.cc ./java/rocksjni/options.cc ./java/rocksjni/write_batch.cc
+
+JAVA_INCLUDE = -I/usr/lib/jvm/java-openjdk/include/ -I/usr/lib/jvm/java-openjdk/include/linux 
+ROCKSDBJNILIB = ./java/librocksdbjni.so
+
+ifeq ($(PLATFORM), OS_MACOSX)
+ROCKSDBJNILIB = ./java/librocksdbjni.jnilib
+JAVA_INCLUDE = -I/System/Library/Frameworks/JavaVM.framework/Headers/
+endif
+
+jni: clean
+	OPT="-fPIC -DNDEBUG -O2" $(MAKE) $(LIBRARY) -j32
+	cd java;$(MAKE) java;
+	rm -f $(ROCKSDBJNILIB)
+	$(CXX) $(CXXFLAGS) -I./java/. $(JAVA_INCLUDE) -shared -fPIC -o $(ROCKSDBJNILIB) $(JNI_NATIVE_SOURCES) $(LIBOBJECTS) $(LDFLAGS) $(COVERAGEFLAGS)
+
+jclean:
+	cd java;$(MAKE) clean;
+	rm -f $(ROCKSDBJNILIB)
+
+jtest:
+	cd java;$(MAKE) sample;$(MAKE) test;
+
 # ---------------------------------------------------------------------------
 #  	Platform-specific compilation
 # ---------------------------------------------------------------------------
@@ -370,20 +445,20 @@ ifeq ($(PLATFORM), IOS)
 PLATFORMSROOT=/Applications/Xcode.app/Contents/Developer/Platforms
 SIMULATORROOT=$(PLATFORMSROOT)/iPhoneSimulator.platform/Developer
 DEVICEROOT=$(PLATFORMSROOT)/iPhoneOS.platform/Developer
-IOSVERSION=$(shell defaults read $(PLATFORMSROOT)/iPhoneOS.platform/versionCFBundleShortVersionString)
+IOSVERSION=$(shell defaults read $(PLATFORMSROOT)/iPhoneOS.platform/version CFBundleShortVersionString)

 .cc.o:
 	mkdir -p ios-x86/$(dir $@)
-	$(SIMULATORROOT)/usr/bin/$(CXX) $(CXXFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 -c $< -o ios-x86/$@ $(COVERAGEFLAGS)
+	$(CXX) $(CXXFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 -arch x86_64 -c $< -o ios-x86/$@
 	mkdir -p ios-arm/$(dir $@)
-	$(DEVICEROOT)/usr/bin/$(CXX) $(CXXFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 -c $< -o ios-arm/$@ $(COVERAGEFLAGS)
+	xcrun -sdk iphoneos $(CXX) $(CXXFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 -arch armv7s -arch arm64 -c $< -o ios-arm/$@
 	lipo ios-x86/$@ ios-arm/$@ -create -output $@

 .c.o:
 	mkdir -p ios-x86/$(dir $@)
-	$(SIMULATORROOT)/usr/bin/$(CC) $(CFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 -c $< -o ios-x86/$@
+	$(CC) $(CFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 -arch x86_64 -c $< -o ios-x86/$@
 	mkdir -p ios-arm/$(dir $@)
-	$(DEVICEROOT)/usr/bin/$(CC) $(CFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 -c $< -o ios-arm/$@
+	xcrun -sdk iphoneos $(CC) $(CFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 -arch armv7s -arch arm64 -c $< -o ios-arm/$@
 	lipo ios-x86/$@ ios-arm/$@ -create -output $@

 else
@@ -423,6 +498,10 @@ depend: $(DEPFILES)
 # working solution.
 ifneq ($(MAKECMDGOALS),clean)
 ifneq ($(MAKECMDGOALS),format)
+ifneq ($(MAKECMDGOALS),jclean)
+ifneq ($(MAKECMDGOALS),jtest)
 -include $(DEPFILES)
 endif
 endif
+endif
+endif
@@ -19,7 +19,8 @@
 #
 #       -DLEVELDB_PLATFORM_POSIX if cstdatomic is present
 #       -DLEVELDB_PLATFORM_NOATOMIC if it is not
-#       -DSNAPPY                     if the Snappy library is present
+#       -DSNAPPY                    if the Snappy library is present
+#       -DLZ4                       if the LZ4 library is present
 #
 # Using gflags in rocksdb:
 # Our project depends on gflags, which requires users to take some extra steps
@@ -38,7 +39,7 @@ if test -z "$OUTPUT"; then
 fi

 # we depend on C++11
-PLATFORM_CXXFLAGS="-std=gnu++11"
+PLATFORM_CXXFLAGS="-std=c++11"
 # we currently depend on POSIX platform
 COMMON_FLAGS="-DROCKSDB_PLATFORM_POSIX"

@@ -48,7 +49,7 @@ if [ -d /mnt/gvfs/third-party -a -z "$CXX" ]; then
    if [ -z "$USE_CLANG" ]; then
        CENTOS_VERSION=`rpm -q --qf "%{VERSION}" \
          $(rpm -q --whatprovides redhat-release)`
-        if [ "$CENTOS_VERSION" = "6" ]; then
+        if [ "$CENTOS_VERSION" -ge "6" ]; then
          source $PWD/build_tools/fbcode.gcc481.sh
        else
          source $PWD/build_tools/fbcode.gcc471.sh
@@ -86,7 +87,7 @@ PLATFORM_SHARED_CFLAGS="-fPIC"
 PLATFORM_SHARED_VERSIONED=false

 # generic port files (working on all platform by #ifdef) go directly in /port
-GENERIC_PORT_FILES=`find $ROCKSDB_ROOT/port -name '*.cc' | tr "\n" " "`
+GENERIC_PORT_FILES=`cd $ROCKSDB_ROOT; find port -name '*.cc' | tr "\n" " "`

 # On GCC, we pick libc's memcmp over GCC's memcmp via -fno-builtin-memcmp
 case "$TARGET_OS" in
@@ -97,6 +98,13 @@ case "$TARGET_OS" in
        PLATFORM_SHARED_LDFLAGS="-dynamiclib -install_name "
        # PORT_FILES=port/darwin/darwin_specific.cc
        ;;
+    IOS)
+        PLATFORM=IOS
+        COMMON_FLAGS="$COMMON_FLAGS -DOS_MACOSX -DIOS_CROSS_COMPILE"
+        PLATFORM_SHARED_EXT=dylib
+        PLATFORM_SHARED_LDFLAGS="-dynamiclib -install_name "
+        CROSS_COMPILE=true
+        ;;
    Linux)
        PLATFORM=OS_LINUX
        COMMON_FLAGS="$COMMON_FLAGS -DOS_LINUX"
@@ -244,6 +252,17 @@ EOF
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lbz2"
    fi

+    # Test whether lz4 library is installed
+    $CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+      #include <lz4.h>
+      #include <lz4hc.h>
+      int main() {}
+EOF
+    if [ "$?" = 0 ]; then
+        COMMON_FLAGS="$COMMON_FLAGS -DLZ4"
+        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -llz4"
+    fi
+
    # Test whether tcmalloc is available
    $CXX $CFLAGS -x c++ - -o /dev/null -ltcmalloc 2>/dev/null  <<EOF
      int main() {}
@@ -47,7 +47,6 @@ fi
 #     ln -s `git rev-parse --show-toplevel`/build_tools/format-diff.sh $PRE_COMMIT_SCRIPT_PATH
 #   fi
 # fi
-
 set -e

 uncommitted_code=`git diff HEAD`
@@ -55,7 +54,6 @@ uncommitted_code=`git diff HEAD`
 # If there's no uncommitted changes, we assume user are doing post-commit
 # format check, in which case we'll check the modified lines from latest commit.
 # Otherwise, we'll check format of the uncommitted code only.
-format_last_commit=0
 if [ -z "$uncommitted_code" ]
 then
  # Check the format of last commit
@@ -5,13 +5,18 @@
 #  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="Create new RocksDB version and prepare it for the release process\n"
 usage+="USAGE: ./make_new_version.sh <version>"

 # -- Pre-check
@@ -28,13 +33,12 @@ if [ $GIT_BRANCH != "master" ]; then
 fi

 title "Adding new tag for this release ..."
-git tag -a "$ROCKSDB_VERSION.fb" -m "Rocksdb $ROCKSDB_VERSION"
+TAG="$ROCKSDB_VERSION.fb"
+$GIT tag -a "$TAG" -m "RocksDB $ROCKSDB_VERSION"

 # Setting up the proxy for remote repo access
-export http_proxy=http://172.31.255.99:8080
-export https_proxy="$http_proxy";
-
 title "Pushing new tag to remote repo ..."
-proxycmd.sh git push origin --tags
+$GIT push origin --tags

-title "Done!"
+title "Tag $TAG is pushed to github; if you want to delete it, please run"
+title "git tags -d $TAG && git push origin :refs/tags/$TAG"
@@ -117,6 +117,27 @@ make release
    --sync=0 \
    --threads=16 > ${STAT_FILE}.readrandom

+# measure readrandom with 6GB block cache and tailing iterator
+./db_bench \
+    --benchmarks=readrandom \
+    --db=$DATA_DIR \
+    --use_existing_db=1 \
+    --bloom_bits=10 \
+    --num=$NUM \
+    --reads=$((NUM / 5)) \
+    --cache_size=6442450944 \
+    --cache_numshardbits=6 \
+    --table_cache_numshardbits=4 \
+    --open_files=55000 \
+    --disable_seek_compaction=1 \
+    --use_tailing_iterator=1 \
+    --statistics=1 \
+    --histogram=1 \
+    --disable_data_sync=1 \
+    --disable_wal=1 \
+    --sync=0 \
+    --threads=16 > ${STAT_FILE}.readrandomtailing
+
 # measure readrandom with 100MB block cache
 ./db_bench \
    --benchmarks=readrandom \
@@ -300,6 +321,7 @@ function send_benchmark_to_ods {
 send_benchmark_to_ods overwrite overwrite $STAT_FILE.overwrite
 send_benchmark_to_ods fillseq fillseq $STAT_FILE.fillseq
 send_benchmark_to_ods readrandom readrandom $STAT_FILE.readrandom
+send_benchmark_to_ods readrandom readrandom_tailing $STAT_FILE.readrandomtailing
 send_benchmark_to_ods readrandom readrandom_smallblockcache $STAT_FILE.readrandomsmallblockcache
 send_benchmark_to_ods readrandom readrandom_memtable_sst $STAT_FILE.readrandom_mem_sst
 send_benchmark_to_ods readrandom readrandom_fillunique_random $STAT_FILE.readrandom_filluniquerandom
@@ -44,6 +44,11 @@ $GCOV --preserve-paths --relative-only --no-output $GCNO_FILES 2>/dev/null |
  tee -a $RECENT_REPORT &&
 echo -e "Generated coverage report for recently updated files: $RECENT_REPORT\n"

+# Unless otherwise specified, we'll not generate html report by default
+if [ -z "$HTML" ]; then
+  exit 0
+fi
+
 # Generate the html report. If we cannot find lcov in this machine, we'll simply
 # skip this step.
 echo "Generating the html coverage report..."
@@ -9,16 +9,16 @@

 #include "db/builder.h"

-#include "db/filename.h"
 #include "db/dbformat.h"
+#include "db/filename.h"
 #include "db/merge_helper.h"
 #include "db/table_cache.h"
 #include "db/version_edit.h"
 #include "rocksdb/db.h"
-#include "rocksdb/table.h"
 #include "rocksdb/env.h"
 #include "rocksdb/iterator.h"
 #include "rocksdb/options.h"
+#include "rocksdb/table.h"
 #include "table/block_based_table_builder.h"
 #include "util/stop_watch.h"

@@ -26,20 +26,18 @@ namespace rocksdb {

 class TableFactory;

-TableBuilder* GetTableBuilder(const Options& options, WritableFile* file,
+TableBuilder* NewTableBuilder(const Options& options,
+                              const InternalKeyComparator& internal_comparator,
+                              WritableFile* file,
                              CompressionType compression_type) {
-  return options.table_factory->GetTableBuilder(options, file,
-                                                compression_type);
+  return options.table_factory->NewTableBuilder(options, internal_comparator,
+                                                file, compression_type);
 }

-Status BuildTable(const std::string& dbname,
-                  Env* env,
-                  const Options& options,
-                  const EnvOptions& soptions,
-                  TableCache* table_cache,
-                  Iterator* iter,
-                  FileMetaData* meta,
-                  const Comparator* user_comparator,
+Status BuildTable(const std::string& dbname, Env* env, const Options& options,
+                  const EnvOptions& soptions, TableCache* table_cache,
+                  Iterator* iter, FileMetaData* meta,
+                  const InternalKeyComparator& internal_comparator,
                  const SequenceNumber newest_snapshot,
                  const SequenceNumber earliest_seqno_in_memtable,
                  const CompressionType compression) {
@@ -64,8 +62,8 @@ Status BuildTable(const std::string& dbname,
      return s;
    }

-    TableBuilder* builder = GetTableBuilder(options, file.get(),
-                                            compression);
+    TableBuilder* builder =
+        NewTableBuilder(options, internal_comparator, file.get(), compression);

    // the first key is the smallest key
    Slice key = iter->key();
@@ -73,8 +71,9 @@ Status BuildTable(const std::string& dbname,
    meta->smallest_seqno = GetInternalKeySeqno(key);
    meta->largest_seqno = meta->smallest_seqno;

-    MergeHelper merge(user_comparator, options.merge_operator.get(),
-                      options.info_log.get(),
+    MergeHelper merge(internal_comparator.user_comparator(),
+                      options.merge_operator.get(), options.info_log.get(),
+                      options.min_partial_merge_operands,
                      true /* internal key corruption is not ok */);

    if (purge) {
@@ -103,8 +102,8 @@ Status BuildTable(const std::string& dbname,
        // If the key is the same as the previous key (and it is not the
        // first key), then we skip it, since it is an older version.
        // Otherwise we output the key and mark it as the "new" previous key.
-        if (!is_first_key && !user_comparator->Compare(prev_ikey.user_key,
-                                                       this_ikey.user_key)) {
+        if (!is_first_key && !internal_comparator.user_comparator()->Compare(
+                                  prev_ikey.user_key, this_ikey.user_key)) {
          // seqno within the same key are in decreasing order
          assert(this_ikey.sequence < prev_ikey.sequence);
        } else {
@@ -202,10 +201,8 @@ Status BuildTable(const std::string& dbname,

    if (s.ok()) {
      // Verify that the table is usable
-      Iterator* it = table_cache->NewIterator(ReadOptions(),
-                                              soptions,
-                                              meta->number,
-                                              meta->file_size);
+      Iterator* it = table_cache->NewIterator(ReadOptions(), soptions,
+                                              internal_comparator, *meta);
      s = it->status();
      delete it;
    }
@@ -24,23 +24,20 @@ class VersionEdit;
 class TableBuilder;
 class WritableFile;

-
-extern TableBuilder* GetTableBuilder(const Options& options, WritableFile* file,
-                                     CompressionType compression_type);
+extern TableBuilder* NewTableBuilder(
+    const Options& options, const InternalKeyComparator& internal_comparator,
+    WritableFile* file, CompressionType compression_type);

 // Build a Table file from the contents of *iter.  The generated file
 // will be named according to meta->number.  On success, the rest of
 // *meta will be filled with metadata about the generated table.
 // If no data is present in *iter, meta->file_size will be set to
 // zero, and no Table file will be produced.
-extern Status BuildTable(const std::string& dbname,
-                         Env* env,
-                         const Options& options,
-                         const EnvOptions& soptions,
-                         TableCache* table_cache,
-                         Iterator* iter,
+extern Status BuildTable(const std::string& dbname, Env* env,
+                         const Options& options, const EnvOptions& soptions,
+                         TableCache* table_cache, Iterator* iter,
                         FileMetaData* meta,
-                         const Comparator* user_comparator,
+                         const InternalKeyComparator& internal_comparator,
                         const SequenceNumber newest_snapshot,
                         const SequenceNumber earliest_seqno_in_memtable,
                         const CompressionType compression);
@@ -17,21 +17,28 @@
 #include "rocksdb/env.h"
 #include "rocksdb/filter_policy.h"
 #include "rocksdb/iterator.h"
+#include "rocksdb/merge_operator.h"
 #include "rocksdb/options.h"
 #include "rocksdb/status.h"
 #include "rocksdb/write_batch.h"
 #include "rocksdb/memtablerep.h"
 #include "rocksdb/universal_compaction.h"
+#include "rocksdb/statistics.h"
+#include "rocksdb/slice_transform.h"
+#include "rocksdb/table.h"

 using rocksdb::Cache;
 using rocksdb::Comparator;
 using rocksdb::CompressionType;
 using rocksdb::DB;
 using rocksdb::Env;
+using rocksdb::InfoLogLevel;
 using rocksdb::FileLock;
 using rocksdb::FilterPolicy;
+using rocksdb::FlushOptions;
 using rocksdb::Iterator;
 using rocksdb::Logger;
+using rocksdb::MergeOperator;
 using rocksdb::NewBloomFilterPolicy;
 using rocksdb::NewLRUCache;
 using rocksdb::Options;
@@ -40,29 +47,33 @@ using rocksdb::Range;
 using rocksdb::ReadOptions;
 using rocksdb::SequentialFile;
 using rocksdb::Slice;
+using rocksdb::SliceTransform;
 using rocksdb::Snapshot;
 using rocksdb::Status;
 using rocksdb::WritableFile;
 using rocksdb::WriteBatch;
 using rocksdb::WriteOptions;
+using rocksdb::LiveFileMetaData;

 using std::shared_ptr;

 extern "C" {

-struct rocksdb_t              { DB*               rep; };
-struct rocksdb_iterator_t     { Iterator*         rep; };
-struct rocksdb_writebatch_t   { WriteBatch        rep; };
-struct rocksdb_snapshot_t     { const Snapshot*   rep; };
-struct rocksdb_readoptions_t  { ReadOptions       rep; };
-struct rocksdb_writeoptions_t { WriteOptions      rep; };
-struct rocksdb_options_t      { Options           rep; };
-struct rocksdb_seqfile_t      { SequentialFile*   rep; };
-struct rocksdb_randomfile_t   { RandomAccessFile* rep; };
-struct rocksdb_writablefile_t { WritableFile*     rep; };
-struct rocksdb_filelock_t     { FileLock*         rep; };
-struct rocksdb_logger_t       { shared_ptr<Logger>  rep; };
-struct rocksdb_cache_t        { shared_ptr<Cache>   rep; };
+struct rocksdb_t                 { DB*               rep; };
+struct rocksdb_iterator_t        { Iterator*         rep; };
+struct rocksdb_writebatch_t      { WriteBatch        rep; };
+struct rocksdb_snapshot_t        { const Snapshot*   rep; };
+struct rocksdb_flushoptions_t    { FlushOptions      rep; };
+struct rocksdb_readoptions_t     { ReadOptions       rep; };
+struct rocksdb_writeoptions_t    { WriteOptions      rep; };
+struct rocksdb_options_t         { Options           rep; };
+struct rocksdb_seqfile_t         { SequentialFile*   rep; };
+struct rocksdb_randomfile_t      { RandomAccessFile* rep; };
+struct rocksdb_writablefile_t    { WritableFile*     rep; };
+struct rocksdb_filelock_t        { FileLock*         rep; };
+struct rocksdb_logger_t          { shared_ptr<Logger>  rep; };
+struct rocksdb_cache_t           { shared_ptr<Cache>   rep; };
+struct rocksdb_livefiles_t       { std::vector<LiveFileMetaData> rep; };

 struct rocksdb_comparator_t : public Comparator {
  void* state_;
@@ -103,6 +114,9 @@ struct rocksdb_filterpolicy_t : public FilterPolicy {
      void*,
      const char* key, size_t length,
      const char* filter, size_t filter_length);
+  void (*delete_filter_)(
+      void*,
+      const char* filter, size_t filter_length);

  virtual ~rocksdb_filterpolicy_t() {
    (*destructor_)(state_);
@@ -122,7 +136,12 @@ struct rocksdb_filterpolicy_t : public FilterPolicy {
    size_t len;
    char* filter = (*create_)(state_, &key_pointers[0], &key_sizes[0], n, &len);
    dst->append(filter, len);
-    free(filter);
+
+    if (delete_filter_ != nullptr) {
+      (*delete_filter_)(state_, filter, len);
+    } else {
+      free(filter);
+    }
  }

  virtual bool KeyMayMatch(const Slice& key, const Slice& filter) const {
@@ -131,21 +150,156 @@ struct rocksdb_filterpolicy_t : public FilterPolicy {
  }
 };

+struct rocksdb_mergeoperator_t : public MergeOperator {
+  void* state_;
+  void (*destructor_)(void*);
+  const char* (*name_)(void*);
+  char* (*full_merge_)(
+      void*,
+      const char* key, size_t key_length,
+      const char* existing_value, size_t existing_value_length,
+      const char* const* operands_list, const size_t* operands_list_length,
+      int num_operands,
+      unsigned char* success, size_t* new_value_length);
+  char* (*partial_merge_)(void*, const char* key, size_t key_length,
+                          const char* const* operands_list,
+                          const size_t* operands_list_length, int num_operands,
+                          unsigned char* success, size_t* new_value_length);
+  void (*delete_value_)(
+      void*,
+      const char* value, size_t value_length);
+
+  virtual ~rocksdb_mergeoperator_t() {
+    (*destructor_)(state_);
+  }
+
+  virtual const char* Name() const {
+    return (*name_)(state_);
+  }
+
+  virtual bool FullMerge(
+      const Slice& key,
+      const Slice* existing_value,
+      const std::deque<std::string>& operand_list,
+      std::string* new_value,
+      Logger* logger) const {
+
+    size_t n = operand_list.size();
+    std::vector<const char*> operand_pointers(n);
+    std::vector<size_t> operand_sizes(n);
+    for (size_t i = 0; i < n; i++) {
+      Slice operand(operand_list[i]);
+      operand_pointers[i] = operand.data();
+      operand_sizes[i] = operand.size();
+    }
+
+    const char* existing_value_data = nullptr;
+    size_t existing_value_len = 0;
+    if (existing_value != nullptr) {
+      existing_value_data = existing_value->data();
+      existing_value_len = existing_value->size();
+    }
+
+    unsigned char success;
+    size_t new_value_len;
+    char* tmp_new_value = (*full_merge_)(
+        state_,
+        key.data(), key.size(),
+        existing_value_data, existing_value_len,
+        &operand_pointers[0], &operand_sizes[0], n,
+        &success, &new_value_len);
+    new_value->assign(tmp_new_value, new_value_len);
+
+    if (delete_value_ != nullptr) {
+      (*delete_value_)(state_, tmp_new_value, new_value_len);
+    } else {
+      free(tmp_new_value);
+    }
+
+    return success;
+  }
+
+  virtual bool PartialMergeMulti(const Slice& key,
+                                 const std::deque<Slice>& operand_list,
+                                 std::string* new_value, Logger* logger) const {
+    size_t operand_count = operand_list.size();
+    std::vector<const char*> operand_pointers(operand_count);
+    std::vector<size_t> operand_sizes(operand_count);
+    for (size_t i = 0; i < operand_count; ++i) {
+      Slice operand(operand_list[i]);
+      operand_pointers[i] = operand.data();
+      operand_sizes[i] = operand.size();
+    }
+
+    unsigned char success;
+    size_t new_value_len;
+    char* tmp_new_value = (*partial_merge_)(
+        state_, key.data(), key.size(), &operand_pointers[0], &operand_sizes[0],
+        operand_count, &success, &new_value_len);
+    new_value->assign(tmp_new_value, new_value_len);
+
+    if (delete_value_ != nullptr) {
+      (*delete_value_)(state_, tmp_new_value, new_value_len);
+    } else {
+      free(tmp_new_value);
+    }
+
+    return success;
+  }
+};
+
 struct rocksdb_env_t {
  Env* rep;
  bool is_default;
 };

+struct rocksdb_slicetransform_t : public SliceTransform {
+  void* state_;
+  void (*destructor_)(void*);
+  const char* (*name_)(void*);
+  char* (*transform_)(
+      void*,
+      const char* key, size_t length,
+      size_t* dst_length);
+  unsigned char (*in_domain_)(
+      void*,
+      const char* key, size_t length);
+  unsigned char (*in_range_)(
+      void*,
+      const char* key, size_t length);
+
+  virtual ~rocksdb_slicetransform_t() {
+    (*destructor_)(state_);
+  }
+
+  virtual const char* Name() const {
+    return (*name_)(state_);
+  }
+
+  virtual Slice Transform(const Slice& src) const {
+    size_t len;
+    char* dst = (*transform_)(state_, src.data(), src.size(), &len);
+    return Slice(dst, len);
+  }
+
+  virtual bool InDomain(const Slice& src) const {
+    return (*in_domain_)(state_, src.data(), src.size());
+  }
+
+  virtual bool InRange(const Slice& src) const {
+    return (*in_range_)(state_, src.data(), src.size());
+  }
+};
+
 struct rocksdb_universal_compaction_options_t {
  rocksdb::CompactionOptionsUniversal *rep;
 };

-
 static bool SaveError(char** errptr, const Status& s) {
-  assert(errptr != NULL);
+  assert(errptr != nullptr);
  if (s.ok()) {
    return false;
-  } else if (*errptr == NULL) {
+  } else if (*errptr == nullptr) {
    *errptr = strdup(s.ToString().c_str());
  } else {
    // TODO(sanjay): Merge with existing error?
@@ -167,7 +321,7 @@ rocksdb_t* rocksdb_open(
    char** errptr) {
  DB* db;
  if (SaveError(errptr, DB::Open(options->rep, std::string(name), &db))) {
-    return NULL;
+    return nullptr;
  }
  rocksdb_t* result = new rocksdb_t;
  result->rep = db;
@@ -197,6 +351,15 @@ void rocksdb_delete(
  SaveError(errptr, db->rep->Delete(options->rep, Slice(key, keylen)));
 }

+void rocksdb_merge(
+    rocksdb_t* db,
+    const rocksdb_writeoptions_t* options,
+    const char* key, size_t keylen,
+    const char* val, size_t vallen,
+    char** errptr) {
+  SaveError(errptr,
+            db->rep->Merge(options->rep, Slice(key, keylen), Slice(val, vallen)));
+}

 void rocksdb_write(
    rocksdb_t* db,
@@ -212,7 +375,7 @@ char* rocksdb_get(
    const char* key, size_t keylen,
    size_t* vallen,
    char** errptr) {
-  char* result = NULL;
+  char* result = nullptr;
  std::string tmp;
  Status s = db->rep->Get(options->rep, Slice(key, keylen), &tmp);
  if (s.ok()) {
@@ -257,7 +420,7 @@ char* rocksdb_property_value(
    // We use strdup() since we expect human readable output.
    return strdup(tmp.c_str());
  } else {
-    return NULL;
+    return nullptr;
  }
 }

@@ -276,15 +439,48 @@ void rocksdb_approximate_sizes(
  delete[] ranges;
 }

+void rocksdb_delete_file(
+    rocksdb_t* db,
+    const char* name) {
+  db->rep->DeleteFile(name);
+}
+
+const rocksdb_livefiles_t* rocksdb_livefiles(
+    rocksdb_t* db) {
+  rocksdb_livefiles_t* result = new rocksdb_livefiles_t;
+  db->rep->GetLiveFilesMetaData(&result->rep);
+  return result;
+}
+
 void rocksdb_compact_range(
    rocksdb_t* db,
    const char* start_key, size_t start_key_len,
    const char* limit_key, size_t limit_key_len) {
  Slice a, b;
  db->rep->CompactRange(
-      // Pass NULL Slice if corresponding "const char*" is NULL
-      (start_key ? (a = Slice(start_key, start_key_len), &a) : NULL),
-      (limit_key ? (b = Slice(limit_key, limit_key_len), &b) : NULL));
+      // Pass nullptr Slice if corresponding "const char*" is nullptr
+      (start_key ? (a = Slice(start_key, start_key_len), &a) : nullptr),
+      (limit_key ? (b = Slice(limit_key, limit_key_len), &b) : nullptr));
+}
+
+void rocksdb_flush(
+    rocksdb_t* db,
+    const rocksdb_flushoptions_t* options,
+    char** errptr) {
+  SaveError(errptr, db->rep->Flush(options->rep));
+}
+
+void rocksdb_disable_file_deletions(
+    rocksdb_t* db,
+    char** errptr) {
+  SaveError(errptr, db->rep->DisableFileDeletions());
+}
+
+void rocksdb_enable_file_deletions(
+    rocksdb_t* db,
+    unsigned char force,
+    char** errptr) {
+  SaveError(errptr, db->rep->EnableFileDeletions(force));
 }

 void rocksdb_destroy_db(
@@ -358,6 +554,10 @@ void rocksdb_writebatch_clear(rocksdb_writebatch_t* b) {
  b->rep.Clear();
 }

+int rocksdb_writebatch_count(rocksdb_writebatch_t* b) {
+  return b->rep.Count();
+}
+
 void rocksdb_writebatch_put(
    rocksdb_writebatch_t* b,
    const char* key, size_t klen,
@@ -365,6 +565,13 @@ void rocksdb_writebatch_put(
  b->rep.Put(Slice(key, klen), Slice(val, vlen));
 }

+void rocksdb_writebatch_merge(
+    rocksdb_writebatch_t* b,
+    const char* key, size_t klen,
+    const char* val, size_t vlen) {
+  b->rep.Merge(Slice(key, klen), Slice(val, vlen));
+}
+
 void rocksdb_writebatch_delete(
    rocksdb_writebatch_t* b,
    const char* key, size_t klen) {
@@ -395,6 +602,11 @@ void rocksdb_writebatch_iterate(
  b->rep.Iterate(&handler);
 }

+const char* rocksdb_writebatch_data(rocksdb_writebatch_t* b, size_t* size) {
+  *size = b->rep.GetDataSize();
+  return b->rep.Data().c_str();
+}
+
 rocksdb_options_t* rocksdb_options_create() {
  return new rocksdb_options_t;
 }
@@ -409,6 +621,12 @@ void rocksdb_options_set_comparator(
  opt->rep.comparator = cmp;
 }

+void rocksdb_options_set_merge_operator(
+    rocksdb_options_t* opt,
+    rocksdb_mergeoperator_t* merge_operator) {
+  opt->rep.merge_operator = std::shared_ptr<MergeOperator>(merge_operator);
+}
+
 void rocksdb_options_set_filter_policy(
    rocksdb_options_t* opt,
    rocksdb_filterpolicy_t* policy) {
@@ -431,7 +649,7 @@ void rocksdb_options_set_paranoid_checks(
 }

 void rocksdb_options_set_env(rocksdb_options_t* opt, rocksdb_env_t* env) {
-  opt->rep.env = (env ? env->rep : NULL);
+  opt->rep.env = (env ? env->rep : nullptr);
 }

 void rocksdb_options_set_info_log(rocksdb_options_t* opt, rocksdb_logger_t* l) {
@@ -440,6 +658,11 @@ void rocksdb_options_set_info_log(rocksdb_options_t* opt, rocksdb_logger_t* l) {
  }
 }

+void rocksdb_options_set_info_log_level(
+    rocksdb_options_t* opt, int v) {
+  opt->rep.info_log_level = static_cast<InfoLogLevel>(v);
+}
+
 void rocksdb_options_set_write_buffer_size(rocksdb_options_t* opt, size_t s) {
  opt->rep.write_buffer_size = s;
 }
@@ -454,6 +677,12 @@ void rocksdb_options_set_cache(rocksdb_options_t* opt, rocksdb_cache_t* c) {
  }
 }

+void rocksdb_options_set_cache_compressed(rocksdb_options_t* opt, rocksdb_cache_t* c) {
+  if (c) {
+    opt->rep.block_cache_compressed = c->rep;
+  }
+}
+
 void rocksdb_options_set_block_size(rocksdb_options_t* opt, size_t s) {
  opt->rep.block_size = s;
 }
@@ -492,6 +721,18 @@ void rocksdb_options_set_max_grandparent_overlap_factor(
  opt->rep.max_grandparent_overlap_factor = n;
 }

+void rocksdb_options_set_max_bytes_for_level_multiplier_additional(
+    rocksdb_options_t* opt, int* level_values, size_t num_levels) {
+  opt->rep.max_bytes_for_level_multiplier_additional.resize(num_levels);
+  for (size_t i = 0; i < num_levels; ++i) {
+    opt->rep.max_bytes_for_level_multiplier_additional[i] = level_values[i];
+  }
+}
+
+void rocksdb_options_enable_statistics(rocksdb_options_t* opt) {
+  opt->rep.statistics = rocksdb::CreateDBStatistics();
+}
+
 void rocksdb_options_set_num_levels(rocksdb_options_t* opt, int n) {
  opt->rep.num_levels = n;
 }
@@ -537,6 +778,16 @@ void rocksdb_options_set_compression_options(
  opt->rep.compression_opts.strategy = strategy;
 }

+void rocksdb_options_set_prefix_extractor(
+    rocksdb_options_t* opt, rocksdb_slicetransform_t* prefix_extractor) {
+  opt->rep.prefix_extractor.reset(prefix_extractor);
+}
+
+void rocksdb_options_set_whole_key_filtering(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.whole_key_filtering = v;
+}
+
 void rocksdb_options_set_disable_data_sync(
    rocksdb_options_t* opt, int disable_data_sync) {
  opt->rep.disableDataSync = disable_data_sync;
@@ -557,6 +808,11 @@ void rocksdb_options_set_db_log_dir(
  opt->rep.db_log_dir = db_log_dir;
 }

+void rocksdb_options_set_wal_dir(
+    rocksdb_options_t* opt, const char* v) {
+  opt->rep.wal_dir = v;
+}
+
 void rocksdb_options_set_WAL_ttl_seconds(rocksdb_options_t* opt, uint64_t ttl) {
  opt->rep.WAL_ttl_seconds = ttl;
 }
@@ -566,6 +822,99 @@ void rocksdb_options_set_WAL_size_limit_MB(
  opt->rep.WAL_size_limit_MB = limit;
 }

+void rocksdb_options_set_manifest_preallocation_size(
+    rocksdb_options_t* opt, size_t v) {
+  opt->rep.manifest_preallocation_size = v;
+}
+
+void rocksdb_options_set_purge_redundant_kvs_while_flush(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.purge_redundant_kvs_while_flush = v;
+}
+
+void rocksdb_options_set_allow_os_buffer(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.allow_os_buffer = v;
+}
+
+void rocksdb_options_set_allow_mmap_reads(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.allow_mmap_reads = v;
+}
+
+void rocksdb_options_set_allow_mmap_writes(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.allow_mmap_writes = v;
+}
+
+void rocksdb_options_set_is_fd_close_on_exec(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.is_fd_close_on_exec = v;
+}
+
+void rocksdb_options_set_skip_log_error_on_recovery(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.skip_log_error_on_recovery = v;
+}
+
+void rocksdb_options_set_stats_dump_period_sec(
+    rocksdb_options_t* opt, unsigned int v) {
+  opt->rep.stats_dump_period_sec = v;
+}
+
+void rocksdb_options_set_block_size_deviation(
+    rocksdb_options_t* opt, int v) {
+  opt->rep.block_size_deviation = v;
+}
+
+void rocksdb_options_set_advise_random_on_open(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.advise_random_on_open = v;
+}
+
+void rocksdb_options_set_access_hint_on_compaction_start(
+    rocksdb_options_t* opt, int v) {
+  switch(v) {
+    case 0:
+      opt->rep.access_hint_on_compaction_start = rocksdb::Options::NONE;
+      break;
+    case 1:
+      opt->rep.access_hint_on_compaction_start = rocksdb::Options::NORMAL;
+      break;
+    case 2:
+      opt->rep.access_hint_on_compaction_start = rocksdb::Options::SEQUENTIAL;
+      break;
+    case 3:
+      opt->rep.access_hint_on_compaction_start = rocksdb::Options::WILLNEED;
+      break;
+  }
+}
+
+void rocksdb_options_set_use_adaptive_mutex(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.use_adaptive_mutex = v;
+}
+
+void rocksdb_options_set_bytes_per_sync(
+    rocksdb_options_t* opt, uint64_t v) {
+  opt->rep.bytes_per_sync = v;
+}
+
+void rocksdb_options_set_verify_checksums_in_compaction(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.verify_checksums_in_compaction = v;
+}
+
+void rocksdb_options_set_filter_deletes(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.filter_deletes = v;
+}
+
+void rocksdb_options_set_max_sequential_skip_in_iterations(
+    rocksdb_options_t* opt, uint64_t v) {
+  opt->rep.max_sequential_skip_in_iterations = v;
+}
+
 void rocksdb_options_set_max_write_buffer_number(rocksdb_options_t* opt, int n) {
  opt->rep.max_write_buffer_number = n;
 }
@@ -582,6 +931,56 @@ void rocksdb_options_set_max_background_flushes(rocksdb_options_t* opt, int n) {
  opt->rep.max_background_flushes = n;
 }

+void rocksdb_options_set_max_log_file_size(rocksdb_options_t* opt, size_t v) {
+  opt->rep.max_log_file_size = v;
+}
+
+void rocksdb_options_set_log_file_time_to_roll(rocksdb_options_t* opt, size_t v) {
+  opt->rep.log_file_time_to_roll = v;
+}
+
+void rocksdb_options_set_keep_log_file_num(rocksdb_options_t* opt, size_t v) {
+  opt->rep.keep_log_file_num = v;
+}
+
+void rocksdb_options_set_soft_rate_limit(rocksdb_options_t* opt, double v) {
+  opt->rep.soft_rate_limit = v;
+}
+
+void rocksdb_options_set_hard_rate_limit(rocksdb_options_t* opt, double v) {
+  opt->rep.hard_rate_limit = v;
+}
+
+void rocksdb_options_set_rate_limit_delay_max_milliseconds(
+    rocksdb_options_t* opt, unsigned int v) {
+  opt->rep.rate_limit_delay_max_milliseconds = v;
+}
+
+void rocksdb_options_set_max_manifest_file_size(
+    rocksdb_options_t* opt, size_t v) {
+  opt->rep.max_manifest_file_size = v;
+}
+
+void rocksdb_options_set_no_block_cache(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.no_block_cache = v;
+}
+
+void rocksdb_options_set_table_cache_numshardbits(
+    rocksdb_options_t* opt, int v) {
+  opt->rep.table_cache_numshardbits = v;
+}
+
+void rocksdb_options_set_table_cache_remove_scan_count_limit(
+    rocksdb_options_t* opt, int v) {
+  opt->rep.table_cache_remove_scan_count_limit = v;
+}
+
+void rocksdb_options_set_arena_block_size(
+    rocksdb_options_t* opt, size_t v) {
+  opt->rep.arena_block_size = v;
+}
+
 void rocksdb_options_set_disable_auto_compactions(rocksdb_options_t* opt, int disable) {
  opt->rep.disable_auto_compactions = disable;
 }
@@ -590,6 +989,11 @@ void rocksdb_options_set_disable_seek_compaction(rocksdb_options_t* opt, int dis
  opt->rep.disable_seek_compaction = disable;
 }

+void rocksdb_options_set_delete_obsolete_files_period_micros(
+    rocksdb_options_t* opt, uint64_t v) {
+  opt->rep.delete_obsolete_files_period_micros = v;
+}
+
 void rocksdb_options_set_source_compaction_factor(
    rocksdb_options_t* opt, int n) {
  opt->rep.expanded_compaction_factor = n;
@@ -607,6 +1011,78 @@ void rocksdb_options_set_memtable_vector_rep(rocksdb_options_t *opt) {
  opt->rep.memtable_factory.reset(factory);
 }

+void rocksdb_options_set_memtable_prefix_bloom_bits(
+    rocksdb_options_t* opt, uint32_t v) {
+  opt->rep.memtable_prefix_bloom_bits = v;
+}
+
+void rocksdb_options_set_memtable_prefix_bloom_probes(
+    rocksdb_options_t* opt, uint32_t v) {
+  opt->rep.memtable_prefix_bloom_probes = v;
+}
+
+void rocksdb_options_set_hash_skip_list_rep(
+    rocksdb_options_t *opt, size_t bucket_count,
+    int32_t skiplist_height, int32_t skiplist_branching_factor) {
+  static rocksdb::MemTableRepFactory* factory = 0;
+  if (!factory) {
+    factory = rocksdb::NewHashSkipListRepFactory(
+        bucket_count, skiplist_height, skiplist_branching_factor);
+  }
+  opt->rep.memtable_factory.reset(factory);
+}
+
+void rocksdb_options_set_hash_link_list_rep(
+    rocksdb_options_t *opt, size_t bucket_count) {
+  static rocksdb::MemTableRepFactory* factory = 0;
+  if (!factory) {
+    factory = rocksdb::NewHashLinkListRepFactory(bucket_count);
+  }
+  opt->rep.memtable_factory.reset(factory);
+}
+
+void rocksdb_options_set_plain_table_factory(
+    rocksdb_options_t *opt, uint32_t user_key_len, int bloom_bits_per_key,
+    double hash_table_ratio, size_t index_sparseness) {
+  static rocksdb::TableFactory* factory = 0;
+  if (!factory) {
+    factory = rocksdb::NewPlainTableFactory(
+        user_key_len, bloom_bits_per_key,
+        hash_table_ratio, index_sparseness);
+  }
+  opt->rep.table_factory.reset(factory);
+}
+
+void rocksdb_options_set_max_successive_merges(
+    rocksdb_options_t* opt, size_t v) {
+  opt->rep.max_successive_merges = v;
+}
+
+void rocksdb_options_set_min_partial_merge_operands(
+    rocksdb_options_t* opt, uint32_t v) {
+  opt->rep.min_partial_merge_operands = v;
+}
+
+void rocksdb_options_set_bloom_locality(
+    rocksdb_options_t* opt, uint32_t v) {
+  opt->rep.bloom_locality = v;
+}
+
+void rocksdb_options_set_allow_thread_local(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.allow_thread_local = v;
+}
+
+void rocksdb_options_set_inplace_update_support(
+    rocksdb_options_t* opt, unsigned char v) {
+  opt->rep.inplace_update_support = v;
+}
+
+void rocksdb_options_set_inplace_update_num_locks(
+    rocksdb_options_t* opt, size_t v) {
+  opt->rep.inplace_update_num_locks = v;
+}
+
 void rocksdb_options_set_compaction_style(rocksdb_options_t *opt, int style) {
  opt->rep.compaction_style = static_cast<rocksdb::CompactionStyle>(style);
 }
@@ -617,42 +1093,18 @@ void rocksdb_options_set_universal_compaction_options(rocksdb_options_t *opt, ro

 /*
 TODO:
-merge_operator
+DB::OpenForReadOnly
+DB::MultiGet
+DB::KeyMayExist
+DB::GetOptions
+DB::GetSortedWalFiles
+DB::GetLatestSequenceNumber
+DB::GetUpdatesSince
+DB::GetDbIdentity
+DB::RunManualCompaction
+custom cache
 compaction_filter
-prefix_extractor
-whole_key_filtering
-max_bytes_for_level_multiplier_additional
-delete_obsolete_files_period_micros
-max_log_file_size
-log_file_time_to_roll
-keep_log_file_num
-soft_rate_limit
-hard_rate_limit
-rate_limit_delay_max_milliseconds
-max_manifest_file_size
-no_block_cache
-table_cache_numshardbits
-table_cache_remove_scan_count_limit
-arena_block_size
-manifest_preallocation_size
-purge_redundant_kvs_while_flush
-allow_os_buffer
-allow_mmap_reads
-allow_mmap_writes
-is_fd_close_on_exec
-skip_log_error_on_recovery
-stats_dump_period_sec
-block_size_deviation
-advise_random_on_open
-access_hint_on_compaction_start
-use_adaptive_mutex
-bytes_per_sync
-filter_deletes
-max_sequential_skip_in_iterations
-table_factory
 table_properties_collectors
-inplace_update_support
-inplace_update_num_locks
 */

 rocksdb_comparator_t* rocksdb_comparator_create(
@@ -687,12 +1139,16 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create(
        void*,
        const char* key, size_t length,
        const char* filter, size_t filter_length),
+    void (*delete_filter)(
+        void*,
+        const char* filter, size_t filter_length),
    const char* (*name)(void*)) {
  rocksdb_filterpolicy_t* result = new rocksdb_filterpolicy_t;
  result->state_ = state;
  result->destructor_ = destructor;
  result->create_ = create_filter;
  result->key_match_ = key_may_match;
+  result->delete_filter_ = delete_filter;
  result->name_ = name;
  return result;
 }
@@ -719,11 +1175,40 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom(int bits_per_key) {
  };
  Wrapper* wrapper = new Wrapper;
  wrapper->rep_ = NewBloomFilterPolicy(bits_per_key);
-  wrapper->state_ = NULL;
+  wrapper->state_ = nullptr;
+  wrapper->delete_filter_ = nullptr;
  wrapper->destructor_ = &Wrapper::DoNothing;
  return wrapper;
 }

+rocksdb_mergeoperator_t* rocksdb_mergeoperator_create(
+    void* state, void (*destructor)(void*),
+    char* (*full_merge)(void*, const char* key, size_t key_length,
+                        const char* existing_value,
+                        size_t existing_value_length,
+                        const char* const* operands_list,
+                        const size_t* operands_list_length, int num_operands,
+                        unsigned char* success, size_t* new_value_length),
+    char* (*partial_merge)(void*, const char* key, size_t key_length,
+                           const char* const* operands_list,
+                           const size_t* operands_list_length, int num_operands,
+                           unsigned char* success, size_t* new_value_length),
+    void (*delete_value)(void*, const char* value, size_t value_length),
+    const char* (*name)(void*)) {
+  rocksdb_mergeoperator_t* result = new rocksdb_mergeoperator_t;
+  result->state_ = state;
+  result->destructor_ = destructor;
+  result->full_merge_ = full_merge;
+  result->partial_merge_ = partial_merge;
+  result->delete_value_ = delete_value;
+  result->name_ = name;
+  return result;
+}
+
+void rocksdb_mergeoperator_destroy(rocksdb_mergeoperator_t* merge_operator) {
+  delete merge_operator;
+}
+
 rocksdb_readoptions_t* rocksdb_readoptions_create() {
  return new rocksdb_readoptions_t;
 }
@@ -743,10 +1228,31 @@ void rocksdb_readoptions_set_fill_cache(
  opt->rep.fill_cache = v;
 }

+void rocksdb_readoptions_set_prefix_seek(
+    rocksdb_readoptions_t* opt, unsigned char v) {
+  opt->rep.prefix_seek = v;
+}
+
 void rocksdb_readoptions_set_snapshot(
    rocksdb_readoptions_t* opt,
    const rocksdb_snapshot_t* snap) {
-  opt->rep.snapshot = (snap ? snap->rep : NULL);
+  opt->rep.snapshot = (snap ? snap->rep : nullptr);
+}
+
+void rocksdb_readoptions_set_prefix(
+    rocksdb_readoptions_t* opt, const char* key, size_t keylen) {
+  Slice prefix = Slice(key, keylen);
+  opt->rep.prefix = &prefix;
+}
+
+void rocksdb_readoptions_set_read_tier(
+    rocksdb_readoptions_t* opt, int v) {
+  opt->rep.read_tier = static_cast<rocksdb::ReadTier>(v);
+}
+
+void rocksdb_readoptions_set_tailing(
+    rocksdb_readoptions_t* opt, unsigned char v) {
+  opt->rep.tailing = v;
 }

 rocksdb_writeoptions_t* rocksdb_writeoptions_create() {
@@ -767,6 +1273,19 @@ void rocksdb_writeoptions_disable_WAL(rocksdb_writeoptions_t* opt, int disable)
 }


+rocksdb_flushoptions_t* rocksdb_flushoptions_create() {
+  return new rocksdb_flushoptions_t;
+}
+
+void rocksdb_flushoptions_destroy(rocksdb_flushoptions_t* opt) {
+  delete opt;
+}
+
+void rocksdb_flushoptions_set_wait(
+    rocksdb_flushoptions_t* opt, unsigned char v) {
+  opt->rep.wait = v;
+}
+
 rocksdb_cache_t* rocksdb_cache_create_lru(size_t capacity) {
  rocksdb_cache_t* c = new rocksdb_cache_t;
  c->rep = NewLRUCache(capacity);
@@ -797,6 +1316,57 @@ void rocksdb_env_destroy(rocksdb_env_t* env) {
  delete env;
 }

+rocksdb_slicetransform_t* rocksdb_slicetransform_create(
+    void* state,
+    void (*destructor)(void*),
+    char* (*transform)(
+        void*,
+        const char* key, size_t length,
+        size_t* dst_length),
+    unsigned char (*in_domain)(
+        void*,
+        const char* key, size_t length),
+    unsigned char (*in_range)(
+        void*,
+        const char* key, size_t length),
+    const char* (*name)(void*)) {
+  rocksdb_slicetransform_t* result = new rocksdb_slicetransform_t;
+  result->state_ = state;
+  result->destructor_ = destructor;
+  result->transform_ = transform;
+  result->in_domain_ = in_domain;
+  result->in_range_ = in_range;
+  result->name_ = name;
+  return result;
+}
+
+void rocksdb_slicetransform_destroy(rocksdb_slicetransform_t* st) {
+  delete st;
+}
+
+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 { return rep_->Name(); }
+    Slice Transform(const Slice& src) const {
+      return rep_->Transform(src);
+    }
+    bool InDomain(const Slice& src) const {
+      return rep_->InDomain(src);
+    }
+    bool InRange(const Slice& src) const {
+      return rep_->InRange(src);
+    }
+    static void DoNothing(void*) { }
+  };
+  Wrapper* wrapper = new Wrapper;
+  wrapper->rep_ = rocksdb::NewFixedPrefixTransform(prefixLen);
+  wrapper->state_ = nullptr;
+  wrapper->destructor_ = &Wrapper::DoNothing;
+  return wrapper;
+}
+
 rocksdb_universal_compaction_options_t* rocksdb_universal_compaction_options_create() {
  rocksdb_universal_compaction_options_t* result = new rocksdb_universal_compaction_options_t;
  result->rep = new rocksdb::CompactionOptionsUniversal;
@@ -839,4 +1409,61 @@ void rocksdb_universal_compaction_options_destroy(
  delete uco;
 }

+void rocksdb_options_set_min_level_to_compress(rocksdb_options_t* opt, int level) {
+  if (level >= 0) {
+    assert(level <= opt->rep.num_levels);
+    opt->rep.compression_per_level.resize(opt->rep.num_levels);
+    for (int i = 0; i < level; i++) {
+      opt->rep.compression_per_level[i] = rocksdb::kNoCompression;
+    }
+    for (int i = level; i < opt->rep.num_levels; i++) {
+      opt->rep.compression_per_level[i] = opt->rep.compression;
+    }
+  }
+}
+
+int rocksdb_livefiles_count(
+  const rocksdb_livefiles_t* lf) {
+  return lf->rep.size();
+}
+
+const char* rocksdb_livefiles_name(
+  const rocksdb_livefiles_t* lf,
+  int index) {
+  return lf->rep[index].name.c_str();
+}
+
+int rocksdb_livefiles_level(
+  const rocksdb_livefiles_t* lf,
+  int index) {
+  return lf->rep[index].level;
+}
+
+size_t rocksdb_livefiles_size(
+  const rocksdb_livefiles_t* lf,
+  int index) {
+  return lf->rep[index].size;
+}
+
+const char* rocksdb_livefiles_smallestkey(
+  const rocksdb_livefiles_t* lf,
+  int index,
+  size_t* size) {
+  *size = lf->rep[index].smallestkey.size();
+  return lf->rep[index].smallestkey.data();
+}
+
+const char* rocksdb_livefiles_largestkey(
+  const rocksdb_livefiles_t* lf,
+  int index,
+  size_t* size) {
+  *size = lf->rep[index].largestkey.size();
+  return lf->rep[index].largestkey.data();
+}
+
+extern void rocksdb_livefiles_destroy(
+  const rocksdb_livefiles_t* lf) {
+  delete lf;
+}
+
 }  // end extern "C"
@@ -154,6 +154,37 @@ unsigned char FilterKeyMatch(
  return fake_filter_result;
 }

+// Custom merge operator
+static void MergeOperatorDestroy(void* arg) { }
+static const char* MergeOperatorName(void* arg) {
+  return "TestMergeOperator";
+}
+static char* MergeOperatorFullMerge(
+    void* arg,
+    const char* key, size_t key_length,
+    const char* existing_value, size_t existing_value_length,
+    const char* const* operands_list, const size_t* operands_list_length,
+    int num_operands,
+    unsigned char* success, size_t* new_value_length) {
+  *new_value_length = 4;
+  *success = 1;
+  char* result = malloc(4);
+  memcpy(result, "fake", 4);
+  return result;
+}
+static char* MergeOperatorPartialMerge(
+    void* arg,
+    const char* key, size_t key_length,
+    const char* const* operands_list, const size_t* operands_list_length,
+    int num_operands,
+    unsigned char* success, size_t* new_value_length) {
+  *new_value_length = 4;
+  *success = 1;
+  char* result = malloc(4);
+  memcpy(result, "fake", 4);
+  return result;
+}
+
 int main(int argc, char** argv) {
  rocksdb_t* db;
  rocksdb_comparator_t* cmp;
@@ -342,7 +373,7 @@ int main(int argc, char** argv) {
    rocksdb_filterpolicy_t* policy;
    if (run == 0) {
      policy = rocksdb_filterpolicy_create(
-          NULL, FilterDestroy, FilterCreate, FilterKeyMatch, FilterName);
+          NULL, FilterDestroy, FilterCreate, FilterKeyMatch, NULL, FilterName);
    } else {
      policy = rocksdb_filterpolicy_create_bloom(10);
    }
@@ -376,6 +407,81 @@ int main(int argc, char** argv) {
    rocksdb_filterpolicy_destroy(policy);
  }

+  StartPhase("merge_operator");
+  {
+    rocksdb_mergeoperator_t* merge_operator;
+    merge_operator = rocksdb_mergeoperator_create(
+        NULL, MergeOperatorDestroy, MergeOperatorFullMerge,
+        MergeOperatorPartialMerge, NULL, MergeOperatorName);
+    // Create new database
+    rocksdb_close(db);
+    rocksdb_destroy_db(options, dbname, &err);
+    rocksdb_options_set_merge_operator(options, merge_operator);
+    db = rocksdb_open(options, dbname, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, "foo", 3, "foovalue", 8, &err);
+    CheckNoError(err);
+    CheckGet(db, roptions, "foo", "foovalue");
+    rocksdb_merge(db, woptions, "foo", 3, "barvalue", 8, &err);
+    CheckNoError(err);
+    CheckGet(db, roptions, "foo", "fake");
+
+    // Merge of a non-existing value
+    rocksdb_merge(db, woptions, "bar", 3, "barvalue", 8, &err);
+    CheckNoError(err);
+    CheckGet(db, roptions, "bar", "fake");
+
+  }
+
+  StartPhase("prefix");
+  {
+    // Create new database
+    rocksdb_close(db);
+    rocksdb_destroy_db(options, dbname, &err);
+
+    rocksdb_filterpolicy_t* policy = rocksdb_filterpolicy_create_bloom(10);
+    rocksdb_options_set_filter_policy(options, policy);
+    rocksdb_options_set_prefix_extractor(options, rocksdb_slicetransform_create_fixed_prefix(3));
+    rocksdb_options_set_hash_skip_list_rep(options, 50000, 4, 4);
+    rocksdb_options_set_plain_table_factory(options, 4, 10, 0.75, 16);
+
+    db = rocksdb_open(options, dbname, &err);
+    CheckNoError(err);
+
+    rocksdb_put(db, woptions, "foo1", 4, "foo", 3, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, "foo2", 4, "foo", 3, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, "foo3", 4, "foo", 3, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, "bar1", 4, "bar", 3, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, "bar2", 4, "bar", 3, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, "bar3", 4, "bar", 3, &err);
+    CheckNoError(err);
+
+    rocksdb_readoptions_set_prefix_seek(roptions, 1);
+
+    rocksdb_iterator_t* iter = rocksdb_create_iterator(db, roptions);
+    CheckCondition(!rocksdb_iter_valid(iter));
+
+    rocksdb_iter_seek(iter, "bar", 3);
+    rocksdb_iter_get_error(iter, &err);
+    CheckNoError(err);
+    CheckCondition(rocksdb_iter_valid(iter));
+
+    CheckIter(iter, "bar1", "bar");
+    rocksdb_iter_next(iter);
+    CheckIter(iter, "bar2", "bar");
+    rocksdb_iter_next(iter);
+    CheckIter(iter, "bar3", "bar");
+    rocksdb_iter_get_error(iter, &err);
+    CheckNoError(err);
+    rocksdb_iter_destroy(iter);
+    rocksdb_filterpolicy_destroy(policy);
+  }
+
  StartPhase("cleanup");
  rocksdb_close(db);
  rocksdb_options_destroy(options);
@@ -39,6 +39,7 @@ Compaction::Compaction(Version* input_version, int level, int out_level,
      score_(0),
      bottommost_level_(false),
      is_full_compaction_(false),
+      is_manual_compaction_(false),
      level_ptrs_(std::vector<size_t>(number_levels_)) {

  input_version_->Ref();
@@ -174,41 +175,71 @@ void Compaction::ResetNextCompactionIndex() {
  input_version_->ResetNextCompactionIndex(level_);
 }

-static void InputSummary(std::vector<FileMetaData*>& files, char* output,
+/*
+for sizes >=10TB, print "XXTB"
+for sizes >=10GB, print "XXGB"
+etc.
+*/
+static void FileSizeSummary(unsigned long long sz, char* output, int len) {
+  const unsigned long long ull10 = 10;
+  if (sz >= ull10<<40) {
+    snprintf(output, len, "%lluTB", sz>>40);
+  } else if (sz >= ull10<<30) {
+    snprintf(output, len, "%lluGB", sz>>30);
+  } else if (sz >= ull10<<20) {
+    snprintf(output, len, "%lluMB", sz>>20);
+  } else if (sz >= ull10<<10) {
+    snprintf(output, len, "%lluKB", sz>>10);
+  } else {
+    snprintf(output, len, "%lluB", sz);
+  }
+}
+
+static int InputSummary(std::vector<FileMetaData*>& files, char* output,
                         int len) {
+  *output = '\0';
  int write = 0;
  for (unsigned int i = 0; i < files.size(); i++) {
    int sz = len - write;
-    int ret = snprintf(output + write, sz, "%lu(%lu) ",
-        (unsigned long)files.at(i)->number,
-        (unsigned long)files.at(i)->file_size);
+    int ret;
+    char sztxt[16];
+    FileSizeSummary((unsigned long long)files.at(i)->file_size, sztxt, 16);
+    ret = snprintf(output + write, sz, "%lu(%s) ",
+                   (unsigned long)files.at(i)->number,
+                   sztxt);
    if (ret < 0 || ret >= sz)
      break;
    write += ret;
  }
+  return write;
 }

 void Compaction::Summary(char* output, int len) {
  int write = snprintf(output, len,
-      "Base version %lu Base level %d, seek compaction:%d, inputs:",
+      "Base version %lu Base level %d, seek compaction:%d, inputs: [",
      (unsigned long)input_version_->GetVersionNumber(),
      level_,
      seek_compaction_);
-  if (write < 0 || write > len) {
+  if (write < 0 || write >= len) {
    return;
  }

-  char level_low_summary[100];
-  InputSummary(inputs_[0], level_low_summary, sizeof(level_low_summary));
-  char level_up_summary[100];
-  if (inputs_[1].size()) {
-    InputSummary(inputs_[1], level_up_summary, sizeof(level_up_summary));
-  } else {
-    level_up_summary[0] = '\0';
+  write += InputSummary(inputs_[0], output+write, len-write);
+  if (write < 0 || write >= len) {
+    return;
  }

-  snprintf(output + write, len - write, "[%s],[%s]",
-      level_low_summary, level_up_summary);
+  write += snprintf(output+write, len-write, "],[");
+  if (write < 0 || write >= len) {
+    return;
+  }
+
+  write += InputSummary(inputs_[1], output+write, len-write);
+  if (write < 0 || write >= len) {
+    return;
+  }
+
+  snprintf(output+write, len-write, "]");
 }

 }  // namespace rocksdb
@@ -78,6 +78,9 @@ class Compaction {
  // Does this compaction include all sst files?
  bool IsFullCompaction() { return is_full_compaction_; }

+  // Was this compaction triggered manually by the client?
+  bool IsManualCompaction() { return is_manual_compaction_; }
+
 private:
  friend class CompactionPicker;
  friend class UniversalCompactionPicker;
@@ -117,6 +120,9 @@ class Compaction {
  // Does this compaction include all sst files?
  bool is_full_compaction_;

+  // Is this compaction requested by the client?
+  bool is_manual_compaction_;
+
  // level_ptrs_ holds indices into input_version_->levels_: our state
  // is that we are positioned at one of the file ranges for each
  // higher level than the ones involved in this compaction (i.e. for
@@ -10,6 +10,7 @@
 #include "db/compaction_picker.h"

 #include <limits>
+#include "util/log_buffer.h"
 #include "util/statistics.h"

 namespace rocksdb {
@@ -177,7 +178,11 @@ bool CompactionPicker::ExpandWhileOverlapping(Compaction* c) {
  // If, after the expansion, there are files that are already under
  // compaction, then we must drop/cancel this compaction.
  int parent_index = -1;
-  if (FilesInCompaction(c->inputs_[0]) ||
+  if (c->inputs_[0].empty()) {
+    Log(options_->info_log,
+        "ExpandWhileOverlapping() failure because zero input files");
+  }
+  if (c->inputs_[0].empty() || FilesInCompaction(c->inputs_[0]) ||
      (c->level() != c->output_level() &&
       ParentRangeInCompaction(c->input_version_, &smallest, &largest, level,
                               &parent_index))) {
@@ -361,10 +366,14 @@ Compaction* CompactionPicker::CompactRange(Version* version, int input_level,

  // Is this compaction creating a file at the bottommost level
  c->SetupBottomMostLevel(true);
+
+  c->is_manual_compaction_ = true;
+
  return c;
 }

-Compaction* LevelCompactionPicker::PickCompaction(Version* version) {
+Compaction* LevelCompactionPicker::PickCompaction(Version* version,
+                                                  LogBuffer* log_buffer) {
  Compaction* c = nullptr;
  int level = -1;

@@ -372,7 +381,7 @@ Compaction* LevelCompactionPicker::PickCompaction(Version* version) {
  // and also in LogAndApply(), otherwise the values could be stale.
  std::vector<uint64_t> size_being_compacted(NumberLevels() - 1);
  SizeBeingCompacted(size_being_compacted);
-  version->Finalize(size_being_compacted);
+  version->ComputeCompactionScore(size_being_compacted);

  // We prefer compactions triggered by too much data in a level over
  // the compactions triggered by seeks.
@@ -541,37 +550,45 @@ Compaction* LevelCompactionPicker::PickCompactionBySize(Version* version,
 // Universal style of compaction. Pick files that are contiguous in
 // time-range to compact.
 //
-Compaction* UniversalCompactionPicker::PickCompaction(Version* version) {
+Compaction* UniversalCompactionPicker::PickCompaction(Version* version,
+                                                      LogBuffer* log_buffer) {
  int level = 0;
  double score = version->compaction_score_[0];

  if ((version->files_[level].size() <
       (unsigned int)options_->level0_file_num_compaction_trigger)) {
-    Log(options_->info_log, "Universal: nothing to do\n");
+    LogToBuffer(log_buffer, "Universal: nothing to do\n");
    return nullptr;
  }
  Version::FileSummaryStorage tmp;
-  Log(options_->info_log, "Universal: candidate files(%lu): %s\n",
-      version->files_[level].size(),
-      version->LevelFileSummary(&tmp, 0));
+  LogToBuffer(log_buffer, "Universal: candidate files(%zu): %s\n",
+              version->files_[level].size(),
+              version->LevelFileSummary(&tmp, 0));

  // Check for size amplification first.
-  Compaction* c = PickCompactionUniversalSizeAmp(version, score);
-  if (c == nullptr) {
-
+  Compaction* c;
+  if ((c = PickCompactionUniversalSizeAmp(version, score, log_buffer)) !=
+      nullptr) {
+    LogToBuffer(log_buffer, "Universal: compacting for size amp\n");
+  } else {
    // Size amplification is within limits. Try reducing read
    // amplification while maintaining file size ratios.
    unsigned int ratio = options_->compaction_options_universal.size_ratio;
-    c = PickCompactionUniversalReadAmp(version, score, ratio, UINT_MAX);

-    // Size amplification and file size ratios are within configured limits.
-    // If max read amplification is exceeding configured limits, then force
-    // compaction without looking at filesize ratios and try to reduce
-    // the number of files to fewer than level0_file_num_compaction_trigger.
-    if (c == nullptr) {
+    if ((c = PickCompactionUniversalReadAmp(version, score, ratio, UINT_MAX,
+                                            log_buffer)) != nullptr) {
+      LogToBuffer(log_buffer, "Universal: compacting for size ratio\n");
+    } else {
+      // Size amplification and file size ratios are within configured limits.
+      // If max read amplification is exceeding configured limits, then force
+      // compaction without looking at filesize ratios and try to reduce
+      // the number of files to fewer than level0_file_num_compaction_trigger.
      unsigned int num_files = version->files_[level].size() -
                               options_->level0_file_num_compaction_trigger;
-      c = PickCompactionUniversalReadAmp(version, score, UINT_MAX, num_files);
+      if ((c = PickCompactionUniversalReadAmp(
+               version, score, UINT_MAX, num_files, log_buffer)) != nullptr) {
+        LogToBuffer(log_buffer, "Universal: compacting for file num\n");
+      }
    }
  }
  if (c == nullptr) {
@@ -623,7 +640,7 @@ Compaction* UniversalCompactionPicker::PickCompaction(Version* version) {
 //
 Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
    Version* version, double score, unsigned int ratio,
-    unsigned int max_number_of_files_to_compact) {
+    unsigned int max_number_of_files_to_compact, LogBuffer* log_buffer) {
  int level = 0;

  unsigned int min_merge_width =
@@ -636,7 +653,7 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
  FileMetaData* f = nullptr;
  bool done = false;
  int start_index = 0;
-  unsigned int candidate_count;
+  unsigned int candidate_count = 0;
  assert(file_by_time.size() == version->files_[level].size());

  unsigned int max_files_to_compact = std::min(max_merge_width,
@@ -658,9 +675,9 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
        candidate_count = 1;
        break;
      }
-      Log(options_->info_log,
-          "Universal: file %lu[%d] being compacted, skipping",
-          (unsigned long)f->number, loop);
+      LogToBuffer(log_buffer,
+                  "Universal: file %lu[%d] being compacted, skipping",
+                  (unsigned long)f->number, loop);
      f = nullptr;
    }

@@ -668,8 +685,8 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
    // first candidate to be compacted.
    uint64_t candidate_size =  f != nullptr? f->file_size : 0;
    if (f != nullptr) {
-      Log(options_->info_log, "Universal: Possible candidate file %lu[%d].",
-          (unsigned long)f->number, loop);
+      LogToBuffer(log_buffer, "Universal: Possible candidate file %lu[%d].",
+                  (unsigned long)f->number, loop);
    }

    // Check if the suceeding files need compaction.
@@ -681,14 +698,32 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
      if (f->being_compacted) {
        break;
      }
-      // pick files if the total candidate file size (increased by the
+      // Pick files if the total/last candidate file size (increased by the
      // specified ratio) is still larger than the next candidate file.
+      // candidate_size is the total size of files picked so far with the
+      // default kCompactionStopStyleTotalSize; with
+      // kCompactionStopStyleSimilarSize, it's simply the size of the last
+      // picked file.
      uint64_t sz = (candidate_size * (100L + ratio)) /100;
      if (sz < f->file_size) {
        break;
      }
+      if (options_->compaction_options_universal.stop_style == kCompactionStopStyleSimilarSize) {
+        // Similar-size stopping rule: also check the last picked file isn't
+        // far larger than the next candidate file.
+        sz = (f->file_size * (100L + ratio)) / 100;
+        if (sz < candidate_size) {
+          // If the small file we've encountered begins a run of similar-size
+          // files, we'll pick them up on a future iteration of the outer
+          // loop. If it's some lonely straggler, it'll eventually get picked
+          // by the last-resort read amp strategy which disregards size ratios.
+          break;
+        }
+        candidate_size = f->file_size;
+      } else { // default kCompactionStopStyleTotalSize
+        candidate_size += f->file_size;
+      }
      candidate_count++;
-      candidate_size += f->file_size;
    }

    // Found a series of consecutive files that need compaction.
@@ -701,12 +736,10 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
           i < loop + candidate_count && i < file_by_time.size(); i++) {
       int index = file_by_time[i];
       FileMetaData* f = version->files_[level][index];
-       Log(options_->info_log,
-           "Universal: Skipping file %lu[%d] with size %lu %d\n",
-           (unsigned long)f->number,
-           i,
-           (unsigned long)f->file_size,
-           f->being_compacted);
+       LogToBuffer(log_buffer,
+                   "Universal: Skipping file %lu[%d] with size %lu %d\n",
+                   (unsigned long)f->number, i, (unsigned long)f->file_size,
+                   f->being_compacted);
      }
    }
  }
@@ -740,10 +773,8 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
    int index = file_by_time[i];
    FileMetaData* f = c->input_version_->files_[level][index];
    c->inputs_[0].push_back(f);
-    Log(options_->info_log, "Universal: Picking file %lu[%d] with size %lu\n",
-        (unsigned long)f->number,
-        i,
-        (unsigned long)f->file_size);
+    LogToBuffer(log_buffer, "Universal: Picking file %lu[%d] with size %lu\n",
+                (unsigned long)f->number, i, (unsigned long)f->file_size);
  }
  return c;
 }
@@ -755,7 +786,7 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalReadAmp(
 // min_merge_width and max_merge_width).
 //
 Compaction* UniversalCompactionPicker::PickCompactionUniversalSizeAmp(
-    Version* version, double score) {
+    Version* version, double score, LogBuffer* log_buffer) {
  int level = 0;

  // percentage flexibilty while reducing size amplification
@@ -779,20 +810,17 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalSizeAmp(
      start_index = loop;         // Consider this as the first candidate.
      break;
    }
-    Log(options_->info_log, "Universal: skipping file %lu[%d] compacted %s",
-        (unsigned long)f->number,
-        loop,
-        " cannot be a candidate to reduce size amp.\n");
+    LogToBuffer(log_buffer, "Universal: skipping file %lu[%d] compacted %s",
+                (unsigned long)f->number, loop,
+                " cannot be a candidate to reduce size amp.\n");
    f = nullptr;
  }
  if (f == nullptr) {
    return nullptr;             // no candidate files
  }

-  Log(options_->info_log, "Universal: First candidate file %lu[%d] %s",
-      (unsigned long)f->number,
-      start_index,
-      " to reduce size amp.\n");
+  LogToBuffer(log_buffer, "Universal: First candidate file %lu[%d] %s",
+              (unsigned long)f->number, start_index, " to reduce size amp.\n");

  // keep adding up all the remaining files
  for (unsigned int loop = start_index; loop < file_by_time.size() - 1;
@@ -800,10 +828,9 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalSizeAmp(
    int index = file_by_time[loop];
    f = version->files_[level][index];
    if (f->being_compacted) {
-      Log(options_->info_log,
-          "Universal: Possible candidate file %lu[%d] %s.",
-          (unsigned long)f->number,
-          loop,
+      LogToBuffer(
+          log_buffer, "Universal: Possible candidate file %lu[%d] %s.",
+          (unsigned long)f->number, loop,
          " is already being compacted. No size amp reduction possible.\n");
      return nullptr;
    }
@@ -820,18 +847,18 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalSizeAmp(

  // size amplification = percentage of additional size
  if (candidate_size * 100 < ratio * earliest_file_size) {
-    Log(options_->info_log,
-        "Universal: size amp not needed. newer-files-total-size %lu "
-        "earliest-file-size %lu",
-        (unsigned long)candidate_size,
-        (unsigned long)earliest_file_size);
+    LogToBuffer(log_buffer,
+                "Universal: size amp not needed. newer-files-total-size %lu "
+                "earliest-file-size %lu",
+                (unsigned long)candidate_size,
+                (unsigned long)earliest_file_size);
    return nullptr;
  } else {
-    Log(options_->info_log,
-        "Universal: size amp needed. newer-files-total-size %lu "
-        "earliest-file-size %lu",
-        (unsigned long)candidate_size,
-        (unsigned long)earliest_file_size);
+    LogToBuffer(log_buffer,
+                "Universal: size amp needed. newer-files-total-size %lu "
+                "earliest-file-size %lu",
+                (unsigned long)candidate_size,
+                (unsigned long)earliest_file_size);
  }
  assert(start_index >= 0 && start_index < file_by_time.size() - 1);

@@ -845,11 +872,9 @@ Compaction* UniversalCompactionPicker::PickCompactionUniversalSizeAmp(
    int index = file_by_time[loop];
    f = c->input_version_->files_[level][index];
    c->inputs_[0].push_back(f);
-    Log(options_->info_log,
-        "Universal: size amp picking file %lu[%d] with size %lu",
-        (unsigned long)f->number,
-        index,
-        (unsigned long)f->file_size);
+    LogToBuffer(log_buffer,
+                "Universal: size amp picking file %lu[%d] with size %lu",
+                (unsigned long)f->number, index, (unsigned long)f->file_size);
  }
  return c;
 }
@@ -19,6 +19,7 @@

 namespace rocksdb {

+class LogBuffer;
 class Compaction;
 class Version;

@@ -31,7 +32,8 @@ class CompactionPicker {
  // Returns nullptr if there is no compaction to be done.
  // Otherwise returns a pointer to a heap-allocated object that
  // describes the compaction.  Caller should delete the result.
-  virtual Compaction* PickCompaction(Version* version) = 0;
+  virtual Compaction* PickCompaction(Version* version,
+                                     LogBuffer* log_buffer) = 0;

  // Return a compaction object for compacting the range [begin,end] in
  // the specified level.  Returns nullptr if there is nothing in that
@@ -127,16 +129,19 @@ class UniversalCompactionPicker : public CompactionPicker {
  UniversalCompactionPicker(const Options* options,
                            const InternalKeyComparator* icmp)
      : CompactionPicker(options, icmp) {}
-  virtual Compaction* PickCompaction(Version* version) override;
+  virtual Compaction* PickCompaction(Version* version,
+                                     LogBuffer* log_buffer) override;

 private:
  // Pick Universal compaction to limit read amplification
  Compaction* PickCompactionUniversalReadAmp(Version* version, double score,
                                             unsigned int ratio,
-                                             unsigned int num_files);
+                                             unsigned int num_files,
+                                             LogBuffer* log_buffer);

  // Pick Universal compaction to limit space amplification.
-  Compaction* PickCompactionUniversalSizeAmp(Version* version, double score);
+  Compaction* PickCompactionUniversalSizeAmp(Version* version, double score,
+                                             LogBuffer* log_buffer);
 };

 class LevelCompactionPicker : public CompactionPicker {
@@ -144,7 +149,8 @@ class LevelCompactionPicker : public CompactionPicker {
  LevelCompactionPicker(const Options* options,
                        const InternalKeyComparator* icmp)
      : CompactionPicker(options, icmp) {}
-  virtual Compaction* PickCompaction(Version* version) override;
+  virtual Compaction* PickCompaction(Version* version,
+                                     LogBuffer* log_buffer) override;

 private:
  // For the specfied level, pick a compaction.
@@ -95,7 +95,12 @@ class CorruptionTest {
    int bad_values = 0;
    int correct = 0;
    std::string value_space;
-    Iterator* iter = db_->NewIterator(ReadOptions());
+    // Do not verify checksums. If we verify checksums then the
+    // db itself will raise errors because data is corrupted.
+    // Instead, we want the reads to be successful and this test
+    // will detect whether the appropriate corruptions have
+    // occured.
+    Iterator* iter = db_->NewIterator(ReadOptions(false, true));
    for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
      uint64_t key;
      Slice in(iter->key());
@@ -371,6 +376,39 @@ TEST(CorruptionTest, UnrelatedKeys) {
  ASSERT_EQ(Value(1000, &tmp2).ToString(), v);
 }

+TEST(CorruptionTest, FileSystemStateCorrupted) {
+  for (int iter = 0; iter < 2; ++iter) {
+    Options options;
+    options.paranoid_checks = true;
+    options.create_if_missing = true;
+    Reopen(&options);
+    Build(10);
+    ASSERT_OK(db_->Flush(FlushOptions()));
+    DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
+    std::vector<LiveFileMetaData> metadata;
+    dbi->GetLiveFilesMetaData(&metadata);
+    ASSERT_GT(metadata.size(), size_t(0));
+    std::string filename = dbname_ + metadata[0].name;
+
+    delete db_;
+    db_ = nullptr;
+
+    if (iter == 0) {  // corrupt file size
+      unique_ptr<WritableFile> file;
+      env_.NewWritableFile(filename, &file, EnvOptions());
+      file->Append(Slice("corrupted sst"));
+      file.reset();
+    } else {  // delete the file
+      env_.DeleteFile(filename);
+    }
+
+    Status x = TryReopen(&options);
+    ASSERT_TRUE(x.IsCorruption());
+    DestroyDB(dbname_, options_);
+    Reopen(&options);
+  }
+}
+
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -7,6 +7,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

+#define __STDC_FORMAT_MACROS
+#include <inttypes.h>
 #include <algorithm>
 #include <string>
 #include <stdint.h>
@@ -17,6 +19,7 @@
 #include "rocksdb/env.h"
 #include "port/port.h"
 #include "util/mutexlock.h"
+#include "util/sync_point.h"

 namespace rocksdb {

@@ -95,20 +98,55 @@ Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
 }

 Status DBImpl::GetSortedWalFiles(VectorLogPtr& files) {
-  // First get sorted files in archive dir, then append sorted files from main
-  // dir to maintain sorted order
-
-  // list wal files in archive dir.
+  // First get sorted files in db dir, then get sorted files from archived
+  // dir, to avoid a race condition where a log file is moved to archived
+  // dir in between.
  Status s;
+  // list wal files in main db dir.
+  VectorLogPtr logs;
+  s = GetSortedWalsOfType(options_.wal_dir, logs, kAliveLogFile);
+  if (!s.ok()) {
+    return s;
+  }
+
+  // Reproduce the race condition where a log file is moved
+  // to archived dir, between these two sync points, used in
+  // (DBTest,TransactionLogIteratorRace)
+  TEST_SYNC_POINT("DBImpl::GetSortedWalFiles:1");
+  TEST_SYNC_POINT("DBImpl::GetSortedWalFiles:2");
+
+  files.clear();
+  // list wal files in archive dir.
  std::string archivedir = ArchivalDirectory(options_.wal_dir);
  if (env_->FileExists(archivedir)) {
-    s = AppendSortedWalsOfType(archivedir, files, kArchivedLogFile);
+    s = GetSortedWalsOfType(archivedir, files, kArchivedLogFile);
    if (!s.ok()) {
      return s;
    }
  }
-  // list wal files in main db dir.
-  return AppendSortedWalsOfType(options_.wal_dir, files, kAliveLogFile);
+
+  uint64_t latest_archived_log_number = 0;
+  if (!files.empty()) {
+    latest_archived_log_number = files.back()->LogNumber();
+    Log(options_.info_log, "Latest Archived log: %" PRIu64,
+        latest_archived_log_number);
+  }
+
+  files.reserve(files.size() + logs.size());
+  for (auto& log : logs) {
+    if (log->LogNumber() > latest_archived_log_number) {
+      files.push_back(std::move(log));
+    } else {
+      // When the race condition happens, we could see the
+      // same log in both db dir and archived dir. Simply
+      // ignore the one in db dir. Note that, if we read
+      // archived dir first, we would have missed the log file.
+      Log(options_.info_log, "%s already moved to archive",
+          log->PathName().c_str());
+    }
+  }
+
+  return s;
 }

 }
@@ -7,23 +7,27 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 #pragma once
+
 #include <atomic>
 #include <deque>
 #include <set>
 #include <utility>
 #include <vector>
+
 #include "db/dbformat.h"
 #include "db/log_writer.h"
 #include "db/snapshot.h"
 #include "db/version_edit.h"
+#include "memtable_list.h"
+#include "port/port.h"
 #include "rocksdb/db.h"
 #include "rocksdb/env.h"
 #include "rocksdb/memtablerep.h"
 #include "rocksdb/transaction_log.h"
-#include "port/port.h"
-#include "util/stats_logger.h"
-#include "memtablelist.h"
 #include "util/autovector.h"
+#include "util/stats_logger.h"
+#include "util/thread_local.h"
+#include "db/internal_stats.h"

 namespace rocksdb {

@@ -32,6 +36,7 @@ class TableCache;
 class Version;
 class VersionEdit;
 class VersionSet;
+class CompactionFilterV2;

 class DBImpl : public DB {
 public:
@@ -81,13 +86,19 @@ class DBImpl : public DB {
                              bool flush_memtable = true);
  virtual Status GetSortedWalFiles(VectorLogPtr& files);
  virtual SequenceNumber GetLatestSequenceNumber() const;
-  virtual Status GetUpdatesSince(SequenceNumber seq_number,
-                                 unique_ptr<TransactionLogIterator>* iter);
+  virtual Status GetUpdatesSince(
+      SequenceNumber seq_number, unique_ptr<TransactionLogIterator>* iter,
+      const TransactionLogIterator::ReadOptions&
+          read_options = TransactionLogIterator::ReadOptions());
  virtual Status DeleteFile(std::string name);

  virtual void GetLiveFilesMetaData(
    std::vector<LiveFileMetaData> *metadata);

+  // checks if all live files exist on file system and that their file sizes
+  // match to our in-memory records
+  virtual Status CheckConsistency();
+
  virtual Status GetDbIdentity(std::string& identity);

  Status RunManualCompaction(int input_level,
@@ -103,7 +114,7 @@ class DBImpl : public DB {
                           const Slice* end);

  // Force current memtable contents to be flushed.
-  Status TEST_FlushMemTable();
+  Status TEST_FlushMemTable(bool wait = true);

  // Wait for memtable compaction
  Status TEST_WaitForFlushMemTable();
@@ -137,6 +148,8 @@ class DBImpl : public DB {
    default_interval_to_delete_obsolete_WAL_ = default_interval_to_delete_obsolete_WAL;
  }

+  void TEST_GetFilesMetaData(std::vector<std::vector<FileMetaData>>* metadata);
+
  // holds references to memtable, all immutable memtables and version
  struct SuperVersion {
    MemTable* mem;
@@ -146,10 +159,13 @@ class DBImpl : public DB {
    // We need to_delete because during Cleanup(), imm->Unref() returns
    // all memtables that we need to free through this vector. We then
    // delete all those memtables outside of mutex, during destruction
-    std::vector<MemTable*> to_delete;
+    autovector<MemTable*> to_delete;
+    // Version number of the current SuperVersion
+    uint64_t version_number;
+    DBImpl* db;

    // should be called outside the mutex
-    explicit SuperVersion(const int num_memtables = 0);
+    SuperVersion() = default;
    ~SuperVersion();
    SuperVersion* Ref();
    // Returns true if this was the last reference and caller should
@@ -163,12 +179,35 @@ class DBImpl : public DB {
    void Cleanup();
    void Init(MemTable* new_mem, MemTableListVersion* new_imm,
              Version* new_current);
+
+    // The value of dummy is not actually used. kSVInUse takes its address as a
+    // mark in the thread local storage to indicate the SuperVersion is in use
+    // by thread. This way, the value of kSVInUse is guaranteed to have no
+    // conflict with SuperVersion object address and portable on different
+    // platform.
+    static int dummy;
+    static void* const kSVInUse;
+    static void* const kSVObsolete;
  };

+  static void SuperVersionUnrefHandle(void* ptr) {
+    // UnrefHandle is called when a thread exists or a ThreadLocalPtr gets
+    // destroyed. When former happens, the thread shouldn't see kSVInUse.
+    // When latter happens, we are in ~DBImpl(), no get should happen as well.
+    assert(ptr != SuperVersion::kSVInUse);
+    DBImpl::SuperVersion* sv = static_cast<DBImpl::SuperVersion*>(ptr);
+    if (sv->Unref()) {
+      sv->db->mutex_.Lock();
+      sv->Cleanup();
+      sv->db->mutex_.Unlock();
+      delete sv;
+    }
+  }
+
  // needed for CleanupIteratorState
  struct DeletionState {
    inline bool HaveSomethingToDelete() const {
-      return  all_files.size() ||
+      return  candidate_files.size() ||
        sst_delete_files.size() ||
        log_delete_files.size();
    }
@@ -176,7 +215,7 @@ class DBImpl : public DB {
    // a list of all files that we'll consider deleting
    // (every once in a while this is filled up with all files
    // in the DB directory)
-    std::vector<std::string> all_files;
+    std::vector<std::string> candidate_files;

    // the list of all live sst files that cannot be deleted
    std::vector<uint64_t> sst_live;
@@ -188,25 +227,24 @@ class DBImpl : public DB {
    std::vector<uint64_t> log_delete_files;

    // a list of memtables to be free
-    std::vector<MemTable *> memtables_to_free;
+    autovector<MemTable*> memtables_to_free;

-    SuperVersion* superversion_to_free; // if nullptr nothing to free
+    autovector<SuperVersion*> superversions_to_free;

    SuperVersion* new_superversion; // if nullptr no new superversion

    // the current manifest_file_number, log_number and prev_log_number
    // that corresponds to the set of files in 'live'.
-    uint64_t manifest_file_number, log_number, prev_log_number;
+    uint64_t manifest_file_number, pending_manifest_file_number, log_number,
+        prev_log_number;

-    explicit DeletionState(const int num_memtables = 0,
-                           bool create_superversion = false) {
+    explicit DeletionState(bool create_superversion = false) {
      manifest_file_number = 0;
+      pending_manifest_file_number = 0;
      log_number = 0;
      prev_log_number = 0;
-      memtables_to_free.reserve(num_memtables);
-      superversion_to_free = nullptr;
      new_superversion =
-          create_superversion ? new SuperVersion(num_memtables) : nullptr;
+          create_superversion ? new SuperVersion() : nullptr;
    }

    ~DeletionState() {
@@ -214,8 +252,10 @@ class DBImpl : public DB {
      for (auto m : memtables_to_free) {
        delete m;
      }
-      // free superversion. if nullptr, this will be noop
-      delete superversion_to_free;
+      // free superversions
+      for (auto s : superversions_to_free) {
+        delete s;
+      }
      // if new_superversion was not used, it will be non-nullptr and needs
      // to be freed here
      delete new_superversion;
@@ -223,7 +263,7 @@ class DBImpl : public DB {
  };

  // Returns the list of live files in 'live' and the list
-  // of all files in the filesystem in 'all_files'.
+  // of all files in the filesystem in 'candidate_files'.
  // If force == false and the last call was less than
  // options_.delete_obsolete_files_period_micros microseconds ago,
  // it will not fill up the deletion_state
@@ -248,8 +288,8 @@ class DBImpl : public DB {
    return internal_comparator_.user_comparator();
  }

-  MemTable* GetMemTable() {
-    return mem_;
+  SuperVersion* GetSuperVersion() {
+    return super_version_;
  }

  Iterator* NewInternalIterator(const ReadOptions&,
@@ -257,7 +297,9 @@ class DBImpl : public DB {

 private:
  friend class DB;
+  friend class InternalStats;
  friend class TailingIterator;
+  friend struct SuperVersion;
  struct CompactionState;
  struct Writer;

@@ -277,7 +319,8 @@ class DBImpl : public DB {
  // Flush the in-memory write buffer to storage.  Switches to a new
  // log-file/memtable and writes a new descriptor iff successful.
  Status FlushMemTableToOutputFile(bool* madeProgress,
-                                   DeletionState& deletion_state);
+                                   DeletionState& deletion_state,
+                                   LogBuffer* log_buffer);

  Status RecoverLogFile(uint64_t log_number, SequenceNumber* max_sequence,
                        bool read_only);
@@ -288,15 +331,19 @@ class DBImpl : public DB {
  // for the entire period. The second method WriteLevel0Table supports
  // concurrent flush memtables to storage.
  Status WriteLevel0TableForRecovery(MemTable* mem, VersionEdit* edit);
-  Status WriteLevel0Table(std::vector<MemTable*> &mems, VersionEdit* edit,
-                                uint64_t* filenumber);
+  Status WriteLevel0Table(autovector<MemTable*>& mems, VersionEdit* edit,
+                          uint64_t* filenumber,
+                          LogBuffer* log_buffer);

  uint64_t SlowdownAmount(int n, double bottom, double top);
  // MakeRoomForWrite will return superversion_to_free through an arugment,
  // which the caller needs to delete. We do it because caller can delete
-  // the superversion outside of mutex
+  // the superversion outside of mutex.
+  // old_log if not nullptr is the old log writer that should be safely
+  // closed whenever DB mutex is released.
  Status MakeRoomForWrite(bool force /* compact even if there is room? */,
-                          SuperVersion** superversion_to_free);
+                          SuperVersion** superversion_to_free,
+                          log::Writer** old_log);
  void BuildBatchGroup(Writer** last_writer,
                       autovector<WriteBatch*>* write_batch_group);

@@ -315,23 +362,45 @@ class DBImpl : public DB {
  static void BGWorkFlush(void* db);
  void BackgroundCallCompaction();
  void BackgroundCallFlush();
-  Status BackgroundCompaction(bool* madeProgress,DeletionState& deletion_state);
-  Status BackgroundFlush(bool* madeProgress, DeletionState& deletion_state);
+  Status BackgroundCompaction(bool* madeProgress, DeletionState& deletion_state,
+                              LogBuffer* log_buffer);
+  Status BackgroundFlush(bool* madeProgress, DeletionState& deletion_state,
+                         LogBuffer* log_buffer);
  void CleanupCompaction(CompactionState* compact, Status status);
  Status DoCompactionWork(CompactionState* compact,
-                          DeletionState& deletion_state);
+                          DeletionState& deletion_state,
+                          LogBuffer* log_buffer);
+
+  // Call compaction filter if is_compaction_v2 is not true. Then iterate
+  // through input and compact the kv-pairs
+  Status ProcessKeyValueCompaction(
+    SequenceNumber visible_at_tip,
+    SequenceNumber earliest_snapshot,
+    SequenceNumber latest_snapshot,
+    DeletionState& deletion_state,
+    bool bottommost_level,
+    int64_t& imm_micros,
+    Iterator* input,
+    CompactionState* compact,
+    bool is_compaction_v2,
+    LogBuffer* log_buffer);
+
+  // Call compaction_filter_v2->Filter() on kv-pairs in compact
+  void CallCompactionFilterV2(CompactionState* compact,
+    CompactionFilterV2* compaction_filter_v2);

  Status OpenCompactionOutputFile(CompactionState* compact);
  Status FinishCompactionOutputFile(CompactionState* compact, Iterator* input);
-  Status InstallCompactionResults(CompactionState* compact);
+  Status InstallCompactionResults(CompactionState* compact,
+                                  LogBuffer* log_buffer);
  void AllocateCompactionOutputFileNumbers(CompactionState* compact);
  void ReleaseCompactionUnusedFileNumbers(CompactionState* compact);

  void PurgeObsoleteWALFiles();

-  Status AppendSortedWalsOfType(const std::string& path,
-                                VectorLogPtr& log_files,
-                                WalFileType type);
+  Status GetSortedWalsOfType(const std::string& path,
+                             VectorLogPtr& log_files,
+                             WalFileType type);

  // Requires: all_logs should be sorted with earliest log file first
  // Retains all log files in all_logs which contain updates with seq no.
@@ -386,7 +455,6 @@ class DBImpl : public DB {
  port::Mutex mutex_;
  port::AtomicPointer shutting_down_;
  port::CondVar bg_cv_;          // Signalled when background work finishes
-  MemTableRepFactory* mem_rep_factory_;
  MemTable* mem_;
  MemTableList imm_;             // Memtable that are not changing
  uint64_t logfile_number_;
@@ -398,6 +466,9 @@ class DBImpl : public DB {
  // InstallSuperVersion(), i.e. incremented every time super_version_
  // changes.
  std::atomic<uint64_t> super_version_number_;
+  // Thread's local copy of SuperVersion pointer
+  // This needs to be destructed after mutex_
+  ThreadLocalPtr* local_sv_;

  std::string host_name_;

@@ -413,6 +484,10 @@ class DBImpl : public DB {
  // part of ongoing compactions.
  std::set<uint64_t> pending_outputs_;

+  // At least one compaction or flush job is pending but not yet scheduled
+  // because of the max background thread limit.
+  bool bg_schedule_needed_;
+
  // count how many background compactions are running or have been scheduled
  int bg_compaction_scheduled_;

@@ -468,88 +543,9 @@ class DBImpl : public DB {
  // enabled and archive size_limit is disabled.
  uint64_t default_interval_to_delete_obsolete_WAL_;

-  // These count the number of microseconds for which MakeRoomForWrite stalls.
-  uint64_t stall_level0_slowdown_;
-  uint64_t stall_memtable_compaction_;
-  uint64_t stall_level0_num_files_;
-  std::vector<uint64_t> stall_leveln_slowdown_;
-  uint64_t stall_level0_slowdown_count_;
-  uint64_t stall_memtable_compaction_count_;
-  uint64_t stall_level0_num_files_count_;
-  std::vector<uint64_t> stall_leveln_slowdown_count_;
-
-  // Time at which this instance was started.
-  const uint64_t started_at_;
-
  bool flush_on_destroy_; // Used when disableWAL is true.

-  // Per level compaction stats.  stats_[level] stores the stats for
-  // compactions that produced data for the specified "level".
-  struct CompactionStats {
-    uint64_t micros;
-
-    // Bytes read from level N during compaction between levels N and N+1
-    int64_t bytes_readn;
-
-    // Bytes read from level N+1 during compaction between levels N and N+1
-    int64_t bytes_readnp1;
-
-    // Total bytes written during compaction between levels N and N+1
-    int64_t bytes_written;
-
-    // Files read from level N during compaction between levels N and N+1
-    int     files_in_leveln;
-
-    // Files read from level N+1 during compaction between levels N and N+1
-    int     files_in_levelnp1;
-
-    // Files written during compaction between levels N and N+1
-    int     files_out_levelnp1;
-
-    // Number of compactions done
-    int     count;
-
-    CompactionStats() : micros(0), bytes_readn(0), bytes_readnp1(0),
-                        bytes_written(0), files_in_leveln(0),
-                        files_in_levelnp1(0), files_out_levelnp1(0),
-                        count(0) { }
-
-    void Add(const CompactionStats& c) {
-      this->micros += c.micros;
-      this->bytes_readn += c.bytes_readn;
-      this->bytes_readnp1 += c.bytes_readnp1;
-      this->bytes_written += c.bytes_written;
-      this->files_in_leveln += c.files_in_leveln;
-      this->files_in_levelnp1 += c.files_in_levelnp1;
-      this->files_out_levelnp1 += c.files_out_levelnp1;
-      this->count += 1;
-    }
-  };
-
-  std::vector<CompactionStats> stats_;
-
-  // Used to compute per-interval statistics
-  struct StatsSnapshot {
-    uint64_t compaction_bytes_read_;     // Bytes read by compaction
-    uint64_t compaction_bytes_written_;  // Bytes written by compaction
-    uint64_t ingest_bytes_;              // Bytes written by user
-    uint64_t wal_bytes_;                 // Bytes written to WAL
-    uint64_t wal_synced_;                // Number of times WAL is synced
-    uint64_t write_with_wal_;            // Number of writes that request WAL
-    // These count the number of writes processed by the calling thread or
-    // another thread.
-    uint64_t write_other_;
-    uint64_t write_self_;
-    double   seconds_up_;
-
-    StatsSnapshot() : compaction_bytes_read_(0), compaction_bytes_written_(0),
-                      ingest_bytes_(0), wal_bytes_(0), wal_synced_(0),
-                      write_with_wal_(0), write_other_(0), write_self_(0),
-                      seconds_up_(0) {}
-  };
-
-  // Counters from the previous time per-interval stats were computed
-  StatsSnapshot last_stats_;
+  InternalStats internal_stats_;

  static const int KEEP_LOG_FILE_NUM = 1000;
  std::string db_absolute_path_;
@@ -566,6 +562,9 @@ class DBImpl : public DB {
  // Guard against multiple concurrent refitting
  bool refitting_level_;

+  // Indicate DB was opened successfully
+  bool opened_successfully_;
+
  // No copying allowed
  DBImpl(const DBImpl&);
  void operator=(const DBImpl&);
@@ -592,6 +591,11 @@ class DBImpl : public DB {
  // deletion_state which can have new_superversion already allocated.
  void InstallSuperVersion(DeletionState& deletion_state);

+  void ResetThreadLocalSuperVersions(DeletionState* deletion_state);
+
+  virtual Status GetPropertiesOfAllTables(TablePropertiesCollection* props)
+      override;
+
  // Function that Get and KeyMayExist call with no_io true or false
  // Note: 'value_found' from KeyMayExist propagates here
  Status GetImpl(const ReadOptions& options,
@@ -56,15 +56,15 @@ Status DBImplReadOnly::Get(const ReadOptions& options,
                   const Slice& key,
                   std::string* value) {
  Status s;
-  MemTable* mem = GetMemTable();
-  Version* current = versions_->current();
  SequenceNumber snapshot = versions_->LastSequence();
+  SuperVersion* super_version = GetSuperVersion();
  MergeContext merge_context;
  LookupKey lkey(key, snapshot);
-  if (mem->Get(lkey, value, &s, merge_context, options_)) {
+  if (super_version->mem->Get(lkey, value, &s, merge_context, options_)) {
  } else {
    Version::GetStats stats;
-    current->Get(options, lkey, value, &s, &merge_context, &stats, options_);
+    super_version->current->Get(options, lkey, value, &s, &merge_context,
+                                &stats, options_);
  }
  return s;
 }
@@ -87,6 +87,9 @@ Status DB::OpenForReadOnly(const Options& options, const std::string& dbname,
  DBImplReadOnly* impl = new DBImplReadOnly(options, dbname);
  impl->mutex_.Lock();
  Status s = impl->Recover(true /* read only */, error_if_log_file_exist);
+  if (s.ok()) {
+    delete impl->InstallSuperVersion(new DBImpl::SuperVersion());
+  }
  impl->mutex_.Unlock();
  if (s.ok()) {
    *dbptr = impl;
@@ -96,4 +99,4 @@ Status DB::OpenForReadOnly(const Options& options, const std::string& dbname,
  return s;
 }

-}
+}   // namespace rocksdb
@@ -39,6 +39,71 @@ static void DumpInternalIter(Iterator* iter) {

 namespace {

+class IterLookupKey {
+ public:
+  IterLookupKey() : key_(space_), buf_size_(sizeof(space_)), key_size_(0) {}
+
+  ~IterLookupKey() { Clear(); }
+
+  Slice GetKey() const {
+    if (key_ != nullptr) {
+      return Slice(key_, key_size_);
+    } else {
+      return Slice();
+    }
+  }
+
+  bool Valid() const { return key_ != nullptr; }
+
+  void Clear() {
+    if (key_ != nullptr && key_ != space_) {
+      delete[] key_;
+    }
+    key_ = space_;
+    buf_size_ = sizeof(buf_size_);
+  }
+
+  // Enlarge the buffer size if needed based on key_size.
+  // By default, static allocated buffer is used. Once there is a key
+  // larger than the static allocated buffer, another buffer is dynamically
+  // allocated, until a larger key buffer is requested. In that case, we
+  // reallocate buffer and delete the old one.
+  void EnlargeBufferIfNeeded(size_t key_size) {
+    // If size is smaller than buffer size, continue using current buffer,
+    // or the static allocated one, as default
+    if (key_size > buf_size_) {
+      // Need to enlarge the buffer.
+      Clear();
+      key_ = new char[key_size];
+      buf_size_ = key_size;
+    }
+    key_size_ = key_size;
+  }
+
+  void SetUserKey(const Slice& user_key) {
+    size_t size = user_key.size();
+    EnlargeBufferIfNeeded(size);
+    memcpy(key_, user_key.data(), size);
+  }
+
+  void SetInternalKey(const Slice& user_key, SequenceNumber s) {
+    size_t usize = user_key.size();
+    EnlargeBufferIfNeeded(usize + sizeof(uint64_t));
+    memcpy(key_, user_key.data(), usize);
+    EncodeFixed64(key_ + usize, PackSequenceAndType(s, kValueTypeForSeek));
+  }
+
+ private:
+  char* key_;
+  size_t buf_size_;
+  size_t key_size_;
+  char space_[32];  // Avoid allocation for short keys
+
+  // No copying allowed
+  IterLookupKey(const IterLookupKey&) = delete;
+  void operator=(const LookupKey&) = delete;
+};
+
 // Memtables and sstables that make the DB representation contain
 // (userkey,seq,type) => uservalue entries.  DBIter
 // combines multiple entries for the same userkey found in the DB
@@ -80,7 +145,7 @@ class DBIter: public Iterator {
  virtual bool Valid() const { return valid_; }
  virtual Slice key() const {
    assert(valid_);
-    return saved_key_;
+    return saved_key_.GetKey();
  }
  virtual Slice value() const {
    assert(valid_);
@@ -102,15 +167,12 @@ class DBIter: public Iterator {
  virtual void SeekToLast();

 private:
-  void FindNextUserEntry(bool skipping);
+  inline void FindNextUserEntry(bool skipping);
+  void FindNextUserEntryInternal(bool skipping);
  void FindPrevUserEntry();
  bool ParseKey(ParsedInternalKey* key);
  void MergeValuesNewToOld();

-  inline void SaveKey(const Slice& k, std::string* dst) {
-    dst->assign(k.data(), k.size());
-  }
-
  inline void ClearSavedValue() {
    if (saved_value_.capacity() > 1048576) {
      std::string empty;
@@ -129,7 +191,7 @@ class DBIter: public Iterator {
  SequenceNumber const sequence_;

  Status status_;
-  std::string saved_key_;     // == current key when direction_==kReverse
+  IterLookupKey saved_key_;   // == current key when direction_==kReverse
  std::string saved_value_;   // == current raw value when direction_==kReverse
  std::string skip_key_;
  Direction direction_;
@@ -169,7 +231,7 @@ void DBIter::Next() {
    }
    if (!iter_->Valid()) {
      valid_ = false;
-      saved_key_.clear();
+      saved_key_.Clear();
      return;
    }
  }
@@ -191,7 +253,15 @@ void DBIter::Next() {
 //
 // NOTE: In between, saved_key_ can point to a user key that has
 //       a delete marker
-void DBIter::FindNextUserEntry(bool skipping) {
+inline void DBIter::FindNextUserEntry(bool skipping) {
+  StopWatchNano timer(env_, false);
+  StartPerfTimer(&timer);
+  FindNextUserEntryInternal(skipping);
+  BumpPerfTime(&perf_context.find_next_user_entry_time, &timer);
+}
+
+// Actual implementation of DBIter::FindNextUserEntry()
+void DBIter::FindNextUserEntryInternal(bool skipping) {
  // Loop until we hit an acceptable entry to yield
  assert(iter_->Valid());
  assert(direction_ == kForward);
@@ -201,7 +271,7 @@ void DBIter::FindNextUserEntry(bool skipping) {
    ParsedInternalKey ikey;
    if (ParseKey(&ikey) && ikey.sequence <= sequence_) {
      if (skipping &&
-          user_comparator_->Compare(ikey.user_key, saved_key_) <= 0) {
+          user_comparator_->Compare(ikey.user_key, saved_key_.GetKey()) <= 0) {
        num_skipped++; // skip this entry
        BumpPerfCount(&perf_context.internal_key_skipped_count);
      } else {
@@ -210,23 +280,23 @@ void DBIter::FindNextUserEntry(bool skipping) {
          case kTypeDeletion:
            // Arrange to skip all upcoming entries for this key since
            // they are hidden by this deletion.
-            SaveKey(ikey.user_key, &saved_key_);
+            saved_key_.SetUserKey(ikey.user_key);
            skipping = true;
            num_skipped = 0;
            BumpPerfCount(&perf_context.internal_delete_skipped_count);
            break;
          case kTypeValue:
            valid_ = true;
-            SaveKey(ikey.user_key, &saved_key_);
+            saved_key_.SetUserKey(ikey.user_key);
            return;
          case kTypeMerge:
            // By now, we are sure the current ikey is going to yield a value
-            SaveKey(ikey.user_key, &saved_key_);
+            saved_key_.SetUserKey(ikey.user_key);
            current_entry_is_merged_ = true;
            valid_ = true;
            MergeValuesNewToOld();  // Go to a different state machine
            return;
-          case kTypeLogData:
+          default:
            assert(false);
            break;
        }
@@ -239,8 +309,8 @@ void DBIter::FindNextUserEntry(bool skipping) {
    if (skipping && num_skipped > max_skip_) {
      num_skipped = 0;
      std::string last_key;
-      AppendInternalKey(&last_key,
-        ParsedInternalKey(Slice(saved_key_), 0, kValueTypeForSeek));
+      AppendInternalKey(&last_key, ParsedInternalKey(saved_key_.GetKey(), 0,
+                                                     kValueTypeForSeek));
      iter_->Seek(last_key);
      RecordTick(statistics_, NUMBER_OF_RESEEKS_IN_ITERATION);
    } else {
@@ -275,7 +345,7 @@ void DBIter::MergeValuesNewToOld() {
      continue;
    }

-    if (user_comparator_->Compare(ikey.user_key, saved_key_) != 0) {
+    if (user_comparator_->Compare(ikey.user_key, saved_key_.GetKey()) != 0) {
      // hit the next user key, stop right here
      break;
    }
@@ -304,21 +374,6 @@ void DBIter::MergeValuesNewToOld() {
      // when complete, add result to operands and continue.
      const Slice& value = iter_->value();
      operands.push_front(value.ToString());
-      while(operands.size() >= 2) {
-        // Call user associative-merge until it returns false
-        if (user_merge_operator_->PartialMerge(ikey.user_key,
-                                               Slice(operands[0]),
-                                               Slice(operands[1]),
-                                               &merge_result,
-                                               logger_)) {
-          operands.pop_front();
-          swap(operands.front(), merge_result);
-        } else {
-          // Associative merge returns false ==> stack the operands
-          break;
-        }
-      }
-
    }
  }

@@ -326,7 +381,7 @@ void DBIter::MergeValuesNewToOld() {
  // a deletion marker.
  // feed null as the existing value to the merge operator, such that
  // client can differentiate this scenario and do things accordingly.
-  user_merge_operator_->FullMerge(saved_key_, nullptr, operands,
+  user_merge_operator_->FullMerge(saved_key_.GetKey(), nullptr, operands,
                                  &saved_value_, logger_);
 }

@@ -345,17 +400,17 @@ void DBIter::Prev() {
    // iter_ is pointing at the current entry.  Scan backwards until
    // the key changes so we can use the normal reverse scanning code.
    assert(iter_->Valid());  // Otherwise valid_ would have been false
-    SaveKey(ExtractUserKey(iter_->key()), &saved_key_);
+    saved_key_.SetUserKey(ExtractUserKey(iter_->key()));
    while (true) {
      iter_->Prev();
      if (!iter_->Valid()) {
        valid_ = false;
-        saved_key_.clear();
+        saved_key_.Clear();
        ClearSavedValue();
        return;
      }
      if (user_comparator_->Compare(ExtractUserKey(iter_->key()),
-                                    saved_key_) < 0) {
+                                    saved_key_.GetKey()) < 0) {
        break;
      }
    }
@@ -370,42 +425,46 @@ void DBIter::FindPrevUserEntry() {
  uint64_t num_skipped = 0;

  ValueType value_type = kTypeDeletion;
+  bool saved_key_valid = true;
  if (iter_->Valid()) {
    do {
      ParsedInternalKey ikey;
-      bool saved_key_cleared = false;
      if (ParseKey(&ikey) && ikey.sequence <= sequence_) {
        if ((value_type != kTypeDeletion) &&
-            user_comparator_->Compare(ikey.user_key, saved_key_) < 0) {
+            user_comparator_->Compare(ikey.user_key, saved_key_.GetKey()) < 0) {
          // We encountered a non-deleted value in entries for previous keys,
          break;
        }
        value_type = ikey.type;
        if (value_type == kTypeDeletion) {
-          saved_key_.clear();
+          saved_key_.Clear();
          ClearSavedValue();
-          saved_key_cleared = true;
+          saved_key_valid = false;
        } else {
          Slice raw_value = iter_->value();
          if (saved_value_.capacity() > raw_value.size() + 1048576) {
            std::string empty;
            swap(empty, saved_value_);
          }
-          SaveKey(ExtractUserKey(iter_->key()), &saved_key_);
+          saved_key_.SetUserKey(ExtractUserKey(iter_->key()));
          saved_value_.assign(raw_value.data(), raw_value.size());
        }
+      } else {
+        // In the case of ikey.sequence > sequence_, we might have already
+        // iterated to a different user key.
+        saved_key_valid = false;
      }
      num_skipped++;
      // If we have sequentially iterated via numerous keys and still not
      // found the prev user-key, then it is better to seek so that we can
      // avoid too many key comparisons. We seek to the first occurence of
      // our current key by looking for max sequence number.
-      if (!saved_key_cleared && num_skipped > max_skip_) {
+      if (saved_key_valid && num_skipped > max_skip_) {
        num_skipped = 0;
        std::string last_key;
-        AppendInternalKey(&last_key,
-          ParsedInternalKey(Slice(saved_key_), kMaxSequenceNumber,
-                            kValueTypeForSeek));
+        AppendInternalKey(&last_key, ParsedInternalKey(saved_key_.GetKey(),
+                                                       kMaxSequenceNumber,
+                                                       kValueTypeForSeek));
        iter_->Seek(last_key);
        RecordTick(statistics_, NUMBER_OF_RESEEKS_IN_ITERATION);
      } else {
@@ -417,7 +476,7 @@ void DBIter::FindPrevUserEntry() {
  if (value_type == kTypeDeletion) {
    // End
    valid_ = false;
-    saved_key_.clear();
+    saved_key_.Clear();
    ClearSavedValue();
    direction_ = kForward;
  } else {
@@ -426,13 +485,16 @@ void DBIter::FindPrevUserEntry() {
 }

 void DBIter::Seek(const Slice& target) {
-  direction_ = kForward;
-  ClearSavedValue();
-  saved_key_.clear();
-  AppendInternalKey(
-      &saved_key_, ParsedInternalKey(target, sequence_, kValueTypeForSeek));
-  iter_->Seek(saved_key_);
+  saved_key_.Clear();
+  // now savved_key is used to store internal key.
+  saved_key_.SetInternalKey(target, sequence_);
+  StopWatchNano internal_seek_timer(env_, false);
+  StartPerfTimer(&internal_seek_timer);
+  iter_->Seek(saved_key_.GetKey());
+  BumpPerfTime(&perf_context.seek_internal_seek_time, &internal_seek_timer);
  if (iter_->Valid()) {
+    direction_ = kForward;
+    ClearSavedValue();
    FindNextUserEntry(false /*not skipping */);
  } else {
    valid_ = false;
@@ -442,7 +504,10 @@ void DBIter::Seek(const Slice& target) {
 void DBIter::SeekToFirst() {
  direction_ = kForward;
  ClearSavedValue();
+  StopWatchNano internal_seek_timer(env_, false);
+  StartPerfTimer(&internal_seek_timer);
  iter_->SeekToFirst();
+  BumpPerfTime(&perf_context.seek_internal_seek_time, &internal_seek_timer);
  if (iter_->Valid()) {
    FindNextUserEntry(false /* not skipping */);
  } else {
@@ -461,7 +526,10 @@ void DBIter::SeekToLast() {

  direction_ = kReverse;
  ClearSavedValue();
+  StopWatchNano internal_seek_timer(env_, false);
+  StartPerfTimer(&internal_seek_timer);
  iter_->SeekToLast();
+  BumpPerfTime(&perf_context.seek_internal_seek_time, &internal_seek_timer);
  FindPrevUserEntry();
 }

@@ -6,16 +6,16 @@
 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
+#include "db/dbformat.h"

 #include <stdio.h>
-#include "db/dbformat.h"
 #include "port/port.h"
 #include "util/coding.h"
 #include "util/perf_context_imp.h"

 namespace rocksdb {

-static uint64_t PackSequenceAndType(uint64_t seq, ValueType t) {
+uint64_t PackSequenceAndType(uint64_t seq, ValueType t) {
  assert(seq <= kMaxSequenceNumber);
  assert(t <= kValueTypeForSeek);
  return (seq << 8) | t;
@@ -72,6 +72,28 @@ int InternalKeyComparator::Compare(const Slice& akey, const Slice& bkey) const {
  return r;
 }

+int InternalKeyComparator::Compare(const ParsedInternalKey& a,
+                                   const ParsedInternalKey& b) const {
+  // Order by:
+  //    increasing user key (according to user-supplied comparator)
+  //    decreasing sequence number
+  //    decreasing type (though sequence# should be enough to disambiguate)
+  int r = user_comparator_->Compare(a.user_key, b.user_key);
+  BumpPerfCount(&perf_context.user_key_comparison_count);
+  if (r == 0) {
+    if (a.sequence > b.sequence) {
+      r = -1;
+    } else if (a.sequence < b.sequence) {
+      r = +1;
+    } else if (a.type > b.type) {
+      r = -1;
+    } else if (a.type < b.type) {
+      r = +1;
+    }
+  }
+  return r;
+}
+
 void InternalKeyComparator::FindShortestSeparator(
      std::string* start,
      const Slice& limit) const {
@@ -25,12 +25,16 @@ class InternalKey;
 // Value types encoded as the last component of internal keys.
 // DO NOT CHANGE THESE ENUM VALUES: they are embedded in the on-disk
 // data structures.
-enum ValueType {
+// The highest bit of the value type needs to be reserved to SST tables
+// for them to do more flexible encoding.
+enum ValueType : unsigned char {
  kTypeDeletion = 0x0,
  kTypeValue = 0x1,
  kTypeMerge = 0x2,
-  kTypeLogData = 0x3
+  kTypeLogData = 0x3,
+  kMaxValue = 0x7F
 };
+
 // kValueTypeForSeek defines the ValueType that should be passed when
 // constructing a ParsedInternalKey object for seeking to a particular
 // sequence number (since we sort sequence numbers in decreasing order
@@ -60,6 +64,8 @@ inline size_t InternalKeyEncodingLength(const ParsedInternalKey& key) {
  return key.user_key.size() + 8;
 }

+extern uint64_t PackSequenceAndType(uint64_t seq, ValueType t);
+
 // Append the serialization of "key" to *result.
 extern void AppendInternalKey(std::string* result,
                              const ParsedInternalKey& key);
@@ -96,6 +102,7 @@ class InternalKeyComparator : public Comparator {
    name_("rocksdb.InternalKeyComparator:" +
          std::string(user_comparator_->Name())) {
  }
+  virtual ~InternalKeyComparator() {}

  virtual const char* Name() const;
  virtual int Compare(const Slice& a, const Slice& b) const;
@@ -107,6 +114,7 @@ class InternalKeyComparator : public Comparator {
  const Comparator* user_comparator() const { return user_comparator_; }

  int Compare(const InternalKey& a, const InternalKey& b) const;
+  int Compare(const ParsedInternalKey& a, const ParsedInternalKey& b) const;
 };

 // Filter policy wrapper that converts from internal keys to user keys
@@ -163,6 +171,7 @@ inline bool ParseInternalKey(const Slice& internal_key,
  unsigned char c = num & 0xff;
  result->sequence = num >> 8;
  result->type = static_cast<ValueType>(c);
+  assert(result->type <= ValueType::kMaxValue);
  result->user_key = Slice(internal_key.data(), n - 8);
  return (c <= static_cast<unsigned char>(kValueTypeForSeek));
 }
@@ -0,0 +1,361 @@
+//  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.
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include "db/internal_stats.h"
+#include "db/db_impl.h"
+#include "db/memtable_list.h"
+
+#include <vector>
+
+namespace rocksdb {
+
+DBPropertyType GetPropertyType(const Slice& property) {
+  Slice in = property;
+  Slice prefix("rocksdb.");
+  if (!in.starts_with(prefix)) return kUnknown;
+  in.remove_prefix(prefix.size());
+
+  if (in.starts_with("num-files-at-level")) {
+    return kNumFilesAtLevel;
+  } else if (in == "levelstats") {
+    return kLevelStats;
+  } else if (in == "stats") {
+    return kStats;
+  } else if (in == "sstables") {
+    return kSsTables;
+  } else if (in == "num-immutable-mem-table") {
+    return kNumImmutableMemTable;
+  } else if (in == "mem-table-flush-pending") {
+    return kMemtableFlushPending;
+  } else if (in == "compaction-pending") {
+    return kCompactionPending;
+  } else if (in == "background-errors") {
+    return kBackgroundErrors;
+  } else if (in == "cur-size-active-mem-table") {
+    return kCurSizeActiveMemTable;
+  }
+  return kUnknown;
+}
+
+bool InternalStats::GetProperty(DBPropertyType property_type,
+                                const Slice& property, std::string* value,
+                                DBImpl* db) {
+  VersionSet* version_set = db->versions_.get();
+  Version* current = version_set->current();
+  const MemTableList& imm = db->imm_;
+  Slice in = property;
+
+  switch (property_type) {
+    case kNumFilesAtLevel: {
+      in.remove_prefix(strlen("rocksdb.num-files-at-level"));
+      uint64_t level;
+      bool ok = ConsumeDecimalNumber(&in, &level) && in.empty();
+      if (!ok || (int)level >= number_levels_) {
+        return false;
+      } else {
+        char buf[100];
+        snprintf(buf, sizeof(buf), "%d",
+                 current->NumLevelFiles(static_cast<int>(level)));
+        *value = buf;
+        return true;
+      }
+    }
+    case kLevelStats: {
+      char buf[1000];
+      snprintf(buf, sizeof(buf),
+               "Level Files Size(MB)\n"
+               "--------------------\n");
+      value->append(buf);
+
+      for (int level = 0; level < number_levels_; level++) {
+        snprintf(buf, sizeof(buf), "%3d %8d %8.0f\n", level,
+                 current->NumLevelFiles(level),
+                 current->NumLevelBytes(level) / 1048576.0);
+        value->append(buf);
+      }
+      return true;
+    }
+    case kStats: {
+      char buf[1000];
+
+      uint64_t wal_bytes = 0;
+      uint64_t wal_synced = 0;
+      uint64_t user_bytes_written = 0;
+      uint64_t write_other = 0;
+      uint64_t write_self = 0;
+      uint64_t write_with_wal = 0;
+      uint64_t total_bytes_written = 0;
+      uint64_t total_bytes_read = 0;
+      uint64_t micros_up = env_->NowMicros() - started_at_;
+      // Add "+1" to make sure seconds_up is > 0 and avoid NaN later
+      double seconds_up = (micros_up + 1) / 1000000.0;
+      uint64_t total_slowdown = 0;
+      uint64_t total_slowdown_count = 0;
+      uint64_t interval_bytes_written = 0;
+      uint64_t interval_bytes_read = 0;
+      uint64_t interval_bytes_new = 0;
+      double interval_seconds_up = 0;
+
+      if (statistics_) {
+        wal_bytes = statistics_->getTickerCount(WAL_FILE_BYTES);
+        wal_synced = statistics_->getTickerCount(WAL_FILE_SYNCED);
+        user_bytes_written = statistics_->getTickerCount(BYTES_WRITTEN);
+        write_other = statistics_->getTickerCount(WRITE_DONE_BY_OTHER);
+        write_self = statistics_->getTickerCount(WRITE_DONE_BY_SELF);
+        write_with_wal = statistics_->getTickerCount(WRITE_WITH_WAL);
+      }
+
+      // Pardon the long line but I think it is easier to read this way.
+      snprintf(
+          buf, sizeof(buf),
+          "                               Compactions\n"
+          "Level  Files Size(MB) Score Time(sec)  Read(MB) Write(MB)    Rn(MB) "
+          " "
+          "Rnp1(MB)  Wnew(MB) RW-Amplify Read(MB/s) Write(MB/s)      Rn     "
+          "Rnp1 "
+          "    Wnp1     NewW    Count   msComp   msStall  Ln-stall Stall-cnt\n"
+          "--------------------------------------------------------------------"
+          "--"
+          "--------------------------------------------------------------------"
+          "--"
+          "----------------------------------------------------------------\n");
+      value->append(buf);
+      for (int level = 0; level < number_levels_; level++) {
+        int files = current->NumLevelFiles(level);
+        if (compaction_stats_[level].micros > 0 || files > 0) {
+          int64_t bytes_read = compaction_stats_[level].bytes_readn +
+                               compaction_stats_[level].bytes_readnp1;
+          int64_t bytes_new = compaction_stats_[level].bytes_written -
+                              compaction_stats_[level].bytes_readnp1;
+          double amplify =
+              (compaction_stats_[level].bytes_readn == 0)
+                  ? 0.0
+                  : (compaction_stats_[level].bytes_written +
+                     compaction_stats_[level].bytes_readnp1 +
+                     compaction_stats_[level].bytes_readn) /
+                        (double)compaction_stats_[level].bytes_readn;
+
+          total_bytes_read += bytes_read;
+          total_bytes_written += compaction_stats_[level].bytes_written;
+
+          uint64_t stalls = level == 0 ? (stall_counts_[LEVEL0_SLOWDOWN] +
+                                          stall_counts_[LEVEL0_NUM_FILES] +
+                                          stall_counts_[MEMTABLE_COMPACTION])
+                                       : stall_leveln_slowdown_count_[level];
+
+          double stall_us = level == 0 ? (stall_micros_[LEVEL0_SLOWDOWN] +
+                                          stall_micros_[LEVEL0_NUM_FILES] +
+                                          stall_micros_[MEMTABLE_COMPACTION])
+                                       : stall_leveln_slowdown_[level];
+
+          snprintf(buf, sizeof(buf),
+                   "%3d %8d %8.0f %5.1f %9.0f %9.0f %9.0f %9.0f %9.0f %9.0f "
+                   "%10.1f %9.1f %11.1f %8d %8d %8d %8d %8d %8d %9.1f %9.1f "
+                   "%9lu\n",
+                   level, files, current->NumLevelBytes(level) / 1048576.0,
+                   current->NumLevelBytes(level) /
+                       version_set->MaxBytesForLevel(level),
+                   compaction_stats_[level].micros / 1e6,
+                   bytes_read / 1048576.0,
+                   compaction_stats_[level].bytes_written / 1048576.0,
+                   compaction_stats_[level].bytes_readn / 1048576.0,
+                   compaction_stats_[level].bytes_readnp1 / 1048576.0,
+                   bytes_new / 1048576.0, amplify,
+                   // +1 to avoid division by 0
+                   (bytes_read / 1048576.0) /
+                       ((compaction_stats_[level].micros + 1) / 1000000.0),
+                   (compaction_stats_[level].bytes_written / 1048576.0) /
+                       ((compaction_stats_[level].micros + 1) / 1000000.0),
+                   compaction_stats_[level].files_in_leveln,
+                   compaction_stats_[level].files_in_levelnp1,
+                   compaction_stats_[level].files_out_levelnp1,
+                   compaction_stats_[level].files_out_levelnp1 -
+                       compaction_stats_[level].files_in_levelnp1,
+                   compaction_stats_[level].count,
+                   (int)((double)compaction_stats_[level].micros / 1000.0 /
+                         (compaction_stats_[level].count + 1)),
+                   (double)stall_us / 1000.0 / (stalls + 1),
+                   stall_us / 1000000.0, (unsigned long)stalls);
+          total_slowdown += stall_leveln_slowdown_[level];
+          total_slowdown_count += stall_leveln_slowdown_count_[level];
+          value->append(buf);
+        }
+      }
+
+      interval_bytes_new = user_bytes_written - last_stats_.ingest_bytes_;
+      interval_bytes_read =
+          total_bytes_read - last_stats_.compaction_bytes_read_;
+      interval_bytes_written =
+          total_bytes_written - last_stats_.compaction_bytes_written_;
+      interval_seconds_up = seconds_up - last_stats_.seconds_up_;
+
+      snprintf(buf, sizeof(buf), "Uptime(secs): %.1f total, %.1f interval\n",
+               seconds_up, interval_seconds_up);
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "Writes cumulative: %llu total, %llu batches, "
+               "%.1f per batch, %.2f ingest GB\n",
+               (unsigned long long)(write_other + write_self),
+               (unsigned long long)write_self,
+               (write_other + write_self) / (double)(write_self + 1),
+               user_bytes_written / (1048576.0 * 1024));
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "WAL cumulative: %llu WAL writes, %llu WAL syncs, "
+               "%.2f writes per sync, %.2f GB written\n",
+               (unsigned long long)write_with_wal,
+               (unsigned long long)wal_synced,
+               write_with_wal / (double)(wal_synced + 1),
+               wal_bytes / (1048576.0 * 1024));
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "Compaction IO cumulative (GB): "
+               "%.2f new, %.2f read, %.2f write, %.2f read+write\n",
+               user_bytes_written / (1048576.0 * 1024),
+               total_bytes_read / (1048576.0 * 1024),
+               total_bytes_written / (1048576.0 * 1024),
+               (total_bytes_read + total_bytes_written) / (1048576.0 * 1024));
+      value->append(buf);
+
+      snprintf(
+          buf, sizeof(buf),
+          "Compaction IO cumulative (MB/sec): "
+          "%.1f new, %.1f read, %.1f write, %.1f read+write\n",
+          user_bytes_written / 1048576.0 / seconds_up,
+          total_bytes_read / 1048576.0 / seconds_up,
+          total_bytes_written / 1048576.0 / seconds_up,
+          (total_bytes_read + total_bytes_written) / 1048576.0 / seconds_up);
+      value->append(buf);
+
+      // +1 to avoid divide by 0 and NaN
+      snprintf(
+          buf, sizeof(buf),
+          "Amplification cumulative: %.1f write, %.1f compaction\n",
+          (double)(total_bytes_written + wal_bytes) / (user_bytes_written + 1),
+          (double)(total_bytes_written + total_bytes_read + wal_bytes) /
+              (user_bytes_written + 1));
+      value->append(buf);
+
+      uint64_t interval_write_other = write_other - last_stats_.write_other_;
+      uint64_t interval_write_self = write_self - last_stats_.write_self_;
+
+      snprintf(buf, sizeof(buf),
+               "Writes interval: %llu total, %llu batches, "
+               "%.1f per batch, %.1f ingest MB\n",
+               (unsigned long long)(interval_write_other + interval_write_self),
+               (unsigned long long)interval_write_self,
+               (double)(interval_write_other + interval_write_self) /
+                   (interval_write_self + 1),
+               (user_bytes_written - last_stats_.ingest_bytes_) / 1048576.0);
+      value->append(buf);
+
+      uint64_t interval_write_with_wal =
+          write_with_wal - last_stats_.write_with_wal_;
+
+      uint64_t interval_wal_synced = wal_synced - last_stats_.wal_synced_;
+      uint64_t interval_wal_bytes = wal_bytes - last_stats_.wal_bytes_;
+
+      snprintf(buf, sizeof(buf),
+               "WAL interval: %llu WAL writes, %llu WAL syncs, "
+               "%.2f writes per sync, %.2f MB written\n",
+               (unsigned long long)interval_write_with_wal,
+               (unsigned long long)interval_wal_synced,
+               interval_write_with_wal / (double)(interval_wal_synced + 1),
+               interval_wal_bytes / (1048576.0 * 1024));
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "Compaction IO interval (MB): "
+               "%.2f new, %.2f read, %.2f write, %.2f read+write\n",
+               interval_bytes_new / 1048576.0, interval_bytes_read / 1048576.0,
+               interval_bytes_written / 1048576.0,
+               (interval_bytes_read + interval_bytes_written) / 1048576.0);
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "Compaction IO interval (MB/sec): "
+               "%.1f new, %.1f read, %.1f write, %.1f read+write\n",
+               interval_bytes_new / 1048576.0 / interval_seconds_up,
+               interval_bytes_read / 1048576.0 / interval_seconds_up,
+               interval_bytes_written / 1048576.0 / interval_seconds_up,
+               (interval_bytes_read + interval_bytes_written) / 1048576.0 /
+                   interval_seconds_up);
+      value->append(buf);
+
+      // +1 to avoid divide by 0 and NaN
+      snprintf(
+          buf, sizeof(buf),
+          "Amplification interval: %.1f write, %.1f compaction\n",
+          (double)(interval_bytes_written + wal_bytes) /
+              (interval_bytes_new + 1),
+          (double)(interval_bytes_written + interval_bytes_read + wal_bytes) /
+              (interval_bytes_new + 1));
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "Stalls(secs): %.3f level0_slowdown, %.3f level0_numfiles, "
+               "%.3f memtable_compaction, %.3f leveln_slowdown\n",
+               stall_micros_[LEVEL0_SLOWDOWN] / 1000000.0,
+               stall_micros_[LEVEL0_NUM_FILES] / 1000000.0,
+               stall_micros_[MEMTABLE_COMPACTION] / 1000000.0,
+               total_slowdown / 1000000.0);
+      value->append(buf);
+
+      snprintf(buf, sizeof(buf),
+               "Stalls(count): %lu level0_slowdown, %lu level0_numfiles, "
+               "%lu memtable_compaction, %lu leveln_slowdown\n",
+               (unsigned long)stall_counts_[LEVEL0_SLOWDOWN],
+               (unsigned long)stall_counts_[LEVEL0_NUM_FILES],
+               (unsigned long)stall_counts_[MEMTABLE_COMPACTION],
+               (unsigned long)total_slowdown_count);
+      value->append(buf);
+
+      last_stats_.compaction_bytes_read_ = total_bytes_read;
+      last_stats_.compaction_bytes_written_ = total_bytes_written;
+      last_stats_.ingest_bytes_ = user_bytes_written;
+      last_stats_.seconds_up_ = seconds_up;
+      last_stats_.wal_bytes_ = wal_bytes;
+      last_stats_.wal_synced_ = wal_synced;
+      last_stats_.write_with_wal_ = write_with_wal;
+      last_stats_.write_other_ = write_other;
+      last_stats_.write_self_ = write_self;
+
+      return true;
+    }
+    case kSsTables:
+      *value = current->DebugString();
+      return true;
+    case kNumImmutableMemTable:
+      *value = std::to_string(imm.size());
+      return true;
+    case kMemtableFlushPending:
+      // Return number of mem tables that are ready to flush (made immutable)
+      *value = std::to_string(imm.IsFlushPending() ? 1 : 0);
+      return true;
+    case kCompactionPending:
+      // 1 if the system already determines at least one compacdtion is needed.
+      // 0 otherwise,
+      *value = std::to_string(current->NeedsCompaction() ? 1 : 0);
+      return true;
+    case kBackgroundErrors:
+      // Accumulated number of  errors in background flushes or compactions.
+      *value = std::to_string(GetBackgroundErrorCount());
+      return true;
+    case kCurSizeActiveMemTable:
+      // Current size of the active memtable
+      *value = std::to_string(db->mem_->ApproximateMemoryUsage());
+      return true;
+    default:
+      return false;
+  }
+}
+
+}  // namespace rocksdb
@@ -0,0 +1,182 @@
+//  Copyright (c) 2013, 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.
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+
+#pragma once
+#include "rocksdb/statistics.h"
+#include "util/statistics.h"
+#include "db/version_set.h"
+
+#include <vector>
+#include <string>
+
+namespace rocksdb {
+
+class MemTableList;
+class DBImpl;
+
+enum DBPropertyType {
+  kNumFilesAtLevel,  // Number of files at a specific level
+  kLevelStats,       // Return number of files and total sizes of each level
+  kStats,            // Return general statitistics of DB
+  kSsTables,         // Return a human readable string of current SST files
+  kNumImmutableMemTable,  // Return number of immutable mem tables
+  kMemtableFlushPending,  // Return 1 if mem table flushing is pending,
+                          // otherwise
+                          // 0.
+  kCompactionPending,     // Return 1 if a compaction is pending. Otherwise 0.
+  kBackgroundErrors,      // Return accumulated background errors encountered.
+  kCurSizeActiveMemTable,  // Return current size of the active memtable
+  kUnknown,
+};
+
+extern DBPropertyType GetPropertyType(const Slice& property);
+
+class InternalStats {
+ public:
+  enum WriteStallType {
+    LEVEL0_SLOWDOWN,
+    MEMTABLE_COMPACTION,
+    LEVEL0_NUM_FILES,
+    WRITE_STALLS_ENUM_MAX,
+  };
+
+  InternalStats(int num_levels, Env* env, Statistics* statistics)
+      : compaction_stats_(num_levels),
+        stall_micros_(WRITE_STALLS_ENUM_MAX, 0),
+        stall_counts_(WRITE_STALLS_ENUM_MAX, 0),
+        stall_leveln_slowdown_(num_levels, 0),
+        stall_leveln_slowdown_count_(num_levels, 0),
+        bg_error_count_(0),
+        number_levels_(num_levels),
+        statistics_(statistics),
+        env_(env),
+        started_at_(env->NowMicros()) {}
+
+  // Per level compaction stats.  compaction_stats_[level] stores the stats for
+  // compactions that produced data for the specified "level".
+  struct CompactionStats {
+    uint64_t micros;
+
+    // Bytes read from level N during compaction between levels N and N+1
+    int64_t bytes_readn;
+
+    // Bytes read from level N+1 during compaction between levels N and N+1
+    int64_t bytes_readnp1;
+
+    // Total bytes written during compaction between levels N and N+1
+    int64_t bytes_written;
+
+    // Files read from level N during compaction between levels N and N+1
+    int files_in_leveln;
+
+    // Files read from level N+1 during compaction between levels N and N+1
+    int files_in_levelnp1;
+
+    // Files written during compaction between levels N and N+1
+    int files_out_levelnp1;
+
+    // Number of compactions done
+    int count;
+
+    CompactionStats()
+        : micros(0),
+          bytes_readn(0),
+          bytes_readnp1(0),
+          bytes_written(0),
+          files_in_leveln(0),
+          files_in_levelnp1(0),
+          files_out_levelnp1(0),
+          count(0) {}
+
+    void Add(const CompactionStats& c) {
+      this->micros += c.micros;
+      this->bytes_readn += c.bytes_readn;
+      this->bytes_readnp1 += c.bytes_readnp1;
+      this->bytes_written += c.bytes_written;
+      this->files_in_leveln += c.files_in_leveln;
+      this->files_in_levelnp1 += c.files_in_levelnp1;
+      this->files_out_levelnp1 += c.files_out_levelnp1;
+      this->count += 1;
+    }
+  };
+
+  void AddCompactionStats(int level, const CompactionStats& stats) {
+    compaction_stats_[level].Add(stats);
+  }
+
+  void RecordWriteStall(WriteStallType write_stall_type, uint64_t micros) {
+    stall_micros_[write_stall_type] += micros;
+    stall_counts_[write_stall_type]++;
+  }
+
+  void RecordLevelNSlowdown(int level, uint64_t micros) {
+    stall_leveln_slowdown_[level] += micros;
+    stall_leveln_slowdown_count_[level] += micros;
+  }
+
+  uint64_t GetBackgroundErrorCount() const { return bg_error_count_; }
+
+  uint64_t BumpAndGetBackgroundErrorCount() { return ++bg_error_count_; }
+
+  bool GetProperty(DBPropertyType property_type, const Slice& property,
+                   std::string* value, DBImpl* db);
+
+ private:
+  std::vector<CompactionStats> compaction_stats_;
+
+  // Used to compute per-interval statistics
+  struct StatsSnapshot {
+    uint64_t compaction_bytes_read_;     // Bytes read by compaction
+    uint64_t compaction_bytes_written_;  // Bytes written by compaction
+    uint64_t ingest_bytes_;              // Bytes written by user
+    uint64_t wal_bytes_;                 // Bytes written to WAL
+    uint64_t wal_synced_;                // Number of times WAL is synced
+    uint64_t write_with_wal_;            // Number of writes that request WAL
+    // These count the number of writes processed by the calling thread or
+    // another thread.
+    uint64_t write_other_;
+    uint64_t write_self_;
+    double seconds_up_;
+
+    StatsSnapshot()
+        : compaction_bytes_read_(0),
+          compaction_bytes_written_(0),
+          ingest_bytes_(0),
+          wal_bytes_(0),
+          wal_synced_(0),
+          write_with_wal_(0),
+          write_other_(0),
+          write_self_(0),
+          seconds_up_(0) {}
+  };
+
+  // Counters from the previous time per-interval stats were computed
+  StatsSnapshot last_stats_;
+
+  // These count the number of microseconds for which MakeRoomForWrite stalls.
+  std::vector<uint64_t> stall_micros_;
+  std::vector<uint64_t> stall_counts_;
+  std::vector<uint64_t> stall_leveln_slowdown_;
+  std::vector<uint64_t> stall_leveln_slowdown_count_;
+
+  // Total number of background errors encountered. Every time a flush task
+  // or compaction task fails, this counter is incremented. The failure can
+  // be caused by any possible reason, including file system errors, out of
+  // resources, or input file corruption. Failing when retrying the same flush
+  // or compaction will cause the counter to increase too.
+  uint64_t bg_error_count_;
+
+  int number_levels_;
+  Statistics* statistics_;
+  Env* env_;
+  uint64_t started_at_;
+};
+
+}  // namespace rocksdb
@@ -17,7 +17,6 @@ namespace log {
 enum RecordType {
  // Zero is reserved for preallocated files
  kZeroType = 0,
-
  kFullType = 1,

  // For fragments
@@ -140,7 +140,9 @@ bool Reader::ReadRecord(Slice* record, std::string* scratch) {

      case kEof:
        if (in_fragmented_record) {
-          ReportCorruption(scratch->size(), "partial record without end(3)");
+          // This can be caused by the writer dying immediately after
+          //  writing a physical record but before completing the next; don't
+          //  treat it as a corruption, just ignore the entire logical record.
          scratch->clear();
        }
        return false;
@@ -264,13 +266,12 @@ unsigned int Reader::ReadPhysicalRecord(Slice* result) {
          eof_offset_ = buffer_.size();
        }
        continue;
-      } else if (buffer_.size() == 0) {
-        // End of file
-        return kEof;
      } else {
-        size_t drop_size = buffer_.size();
+        // Note that if buffer_ is non-empty, we have a truncated header at the
+        //  end of the file, which can be caused by the writer crashing in the
+        //  middle of writing the header. Instead of considering this an error,
+        //  just report EOF.
        buffer_.clear();
-        ReportCorruption(drop_size, "truncated record at end of file");
        return kEof;
      }
    }
@@ -284,14 +285,22 @@ unsigned int Reader::ReadPhysicalRecord(Slice* result) {
    if (kHeaderSize + length > buffer_.size()) {
      size_t drop_size = buffer_.size();
      buffer_.clear();
-      ReportCorruption(drop_size, "bad record length");
-      return kBadRecord;
+      if (!eof_) {
+        ReportCorruption(drop_size, "bad record length");
+        return kBadRecord;
+      }
+      // If the end of the file has been reached without reading |length| bytes
+      // of payload, assume the writer died in the middle of writing the record.
+      // Don't report a corruption.
+      return kEof;
    }

    if (type == kZeroType && length == 0) {
      // Skip zero length record without reporting any drops since
      // such records are produced by the mmap based writing code in
      // env_posix.cc that preallocates file regions.
+      // NOTE: this should never happen in DB written by new RocksDB versions,
+      // since we turn off mmap writes to manifest and log files
      buffer_.clear();
      return kBadRecord;
    }
@@ -446,20 +446,32 @@ TEST(LogTest, BadRecordType) {
  ASSERT_EQ("OK", MatchError("unknown record type"));
 }

-TEST(LogTest, TruncatedTrailingRecord) {
+TEST(LogTest, TruncatedTrailingRecordIsIgnored) {
  Write("foo");
  ShrinkSize(4);   // Drop all payload as well as a header byte
  ASSERT_EQ("EOF", Read());
-  ASSERT_EQ((unsigned int)(kHeaderSize - 1), DroppedBytes());
-  ASSERT_EQ("OK", MatchError("truncated record at end of file"));
+  // Truncated last record is ignored, not treated as an error
+  ASSERT_EQ(0U, DroppedBytes());
+  ASSERT_EQ("", ReportMessage());
 }

 TEST(LogTest, BadLength) {
+  const int kPayloadSize = kBlockSize - kHeaderSize;
+  Write(BigString("bar", kPayloadSize));
+  Write("foo");
+  // Least significant size byte is stored in header[4].
+  IncrementByte(4, 1);
+  ASSERT_EQ("foo", Read());
+  ASSERT_EQ(kBlockSize, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("bad record length"));
+}
+
+TEST(LogTest, BadLengthAtEndIsIgnored) {
  Write("foo");
  ShrinkSize(1);
  ASSERT_EQ("EOF", Read());
-  ASSERT_EQ((unsigned int)(kHeaderSize + 2), DroppedBytes());
-  ASSERT_EQ("OK", MatchError("bad record length"));
+  ASSERT_EQ(0U, DroppedBytes());
+  ASSERT_EQ("", ReportMessage());
 }

 TEST(LogTest, ChecksumMismatch) {
@@ -510,6 +522,24 @@ TEST(LogTest, UnexpectedFirstType) {
  ASSERT_EQ("OK", MatchError("partial record without end"));
 }

+TEST(LogTest, MissingLastIsIgnored) {
+  Write(BigString("bar", kBlockSize));
+  // Remove the LAST block, including header.
+  ShrinkSize(14);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ("", ReportMessage());
+  ASSERT_EQ(0U, DroppedBytes());
+}
+
+TEST(LogTest, PartialLastIsIgnored) {
+  Write(BigString("bar", kBlockSize));
+  // Cause a bad record length in the LAST block.
+  ShrinkSize(1);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ("", ReportMessage());
+  ASSERT_EQ(0U, DroppedBytes());
+}
+
 TEST(LogTest, ErrorJoinsRecords) {
  // Consider two fragmented records:
  //    first(R1) last(R1) first(R2) last(R2)
@@ -10,6 +10,7 @@
 #include "db/memtable.h"

 #include <memory>
+#include <algorithm>

 #include "db/dbformat.h"
 #include "db/merge_context.h"
@@ -17,28 +18,25 @@
 #include "rocksdb/env.h"
 #include "rocksdb/iterator.h"
 #include "rocksdb/merge_operator.h"
+#include "rocksdb/slice_transform.h"
+#include "util/arena.h"
 #include "util/coding.h"
-#include "util/mutexlock.h"
 #include "util/murmurhash.h"
+#include "util/mutexlock.h"
+#include "util/perf_context_imp.h"
 #include "util/statistics.h"
-
-namespace std {
-template <>
-struct hash<rocksdb::Slice> {
-  size_t operator()(const rocksdb::Slice& slice) const {
-    return MurmurHash(slice.data(), slice.size(), 0);
-  }
-};
-}
+#include "util/stop_watch.h"

 namespace rocksdb {

 MemTable::MemTable(const InternalKeyComparator& cmp, const Options& options)
    : comparator_(cmp),
      refs_(0),
-      arena_impl_(options.arena_block_size),
-      table_(options.memtable_factory->CreateMemTableRep(comparator_,
-                                                         &arena_impl_)),
+      kArenaBlockSize(OptimizeBlockSize(options.arena_block_size)),
+      kWriteBufferSize(options.write_buffer_size),
+      arena_(options.arena_block_size),
+      table_(options.memtable_factory->CreateMemTableRep(
+          comparator_, &arena_, options.prefix_extractor.get())),
      flush_in_progress_(false),
      flush_completed_(false),
      file_number_(0),
@@ -46,23 +44,97 @@ MemTable::MemTable(const InternalKeyComparator& cmp, const Options& options)
      mem_next_logfile_number_(0),
      mem_logfile_number_(0),
      locks_(options.inplace_update_support ? options.inplace_update_num_locks
-                                            : 0) {}
+                                            : 0),
+      prefix_extractor_(options.prefix_extractor.get()),
+      should_flush_(ShouldFlushNow()) {
+  // if should_flush_ == true without an entry inserted, something must have
+  // gone wrong already.
+  assert(!should_flush_);
+  if (prefix_extractor_ && options.memtable_prefix_bloom_bits > 0) {
+    prefix_bloom_.reset(new DynamicBloom(options.memtable_prefix_bloom_bits,
+                                         options.bloom_locality,
+                                         options.memtable_prefix_bloom_probes));
+  }
+}

 MemTable::~MemTable() {
  assert(refs_ == 0);
 }

 size_t MemTable::ApproximateMemoryUsage() {
-  return arena_impl_.ApproximateMemoryUsage() +
-         table_->ApproximateMemoryUsage();
+  return arena_.ApproximateMemoryUsage() + table_->ApproximateMemoryUsage();
 }

-int MemTable::KeyComparator::operator()(const char* aptr, const char* bptr)
+bool MemTable::ShouldFlushNow() const {
+  // In a lot of times, we cannot allocate arena blocks that exactly matches the
+  // buffer size. Thus we have to decide if we should over-allocate or
+  // under-allocate.
+  // This constant avariable can be interpreted as: if we still have more than
+  // "kAllowOverAllocationRatio * kArenaBlockSize" space left, we'd try to over
+  // allocate one more block.
+  const double kAllowOverAllocationRatio = 0.6;
+
+  // If arena still have room for new block allocation, we can safely say it
+  // shouldn't flush.
+  auto allocated_memory =
+      table_->ApproximateMemoryUsage() + arena_.MemoryAllocatedBytes();
+
+  // if we can still allocate one more block without exceeding the
+  // over-allocation ratio, then we should not flush.
+  if (allocated_memory + kArenaBlockSize <
+      kWriteBufferSize + kArenaBlockSize * kAllowOverAllocationRatio) {
+    return false;
+  }
+
+  // if user keeps adding entries that exceeds kWriteBufferSize, we need to
+  // flush earlier even though we still have much available memory left.
+  if (allocated_memory >
+      kWriteBufferSize + kArenaBlockSize * kAllowOverAllocationRatio) {
+    return true;
+  }
+
+  // In this code path, Arena has already allocated its "last block", which
+  // means the total allocatedmemory size is either:
+  //  (1) "moderately" over allocated the memory (no more than `0.6 * arena
+  // block size`. Or,
+  //  (2) the allocated memory is less than write buffer size, but we'll stop
+  // here since if we allocate a new arena block, we'll over allocate too much
+  // more (half of the arena block size) memory.
+  //
+  // In either case, to avoid over-allocate, the last block will stop allocation
+  // when its usage reaches a certain ratio, which we carefully choose "0.75
+  // full" as the stop condition because it addresses the following issue with
+  // great simplicity: What if the next inserted entry's size is
+  // bigger than AllocatedAndUnused()?
+  //
+  // The answer is: if the entry size is also bigger than 0.25 *
+  // kArenaBlockSize, a dedicated block will be allocated for it; otherwise
+  // arena will anyway skip the AllocatedAndUnused() and allocate a new, empty
+  // and regular block. In either case, we *overly* over-allocated.
+  //
+  // Therefore, setting the last block to be at most "0.75 full" avoids both
+  // cases.
+  //
+  // NOTE: the average percentage of waste space of this approach can be counted
+  // as: "arena block size * 0.25 / write buffer size". User who specify a small
+  // write buffer size and/or big arena block size may suffer.
+  return arena_.AllocatedAndUnused() < kArenaBlockSize / 4;
+}
+
+int MemTable::KeyComparator::operator()(const char* prefix_len_key1,
+                                        const char* prefix_len_key2) const {
+  // Internal keys are encoded as length-prefixed strings.
+  Slice k1 = GetLengthPrefixedSlice(prefix_len_key1);
+  Slice k2 = GetLengthPrefixedSlice(prefix_len_key2);
+  return comparator.Compare(k1, k2);
+}
+
+int MemTable::KeyComparator::operator()(const char* prefix_len_key,
+                                        const Slice& key)
    const {
  // Internal keys are encoded as length-prefixed strings.
-  Slice a = GetLengthPrefixedSlice(aptr);
-  Slice b = GetLengthPrefixedSlice(bptr);
-  return comparator.Compare(a, b);
+  Slice a = GetLengthPrefixedSlice(prefix_len_key);
+  return comparator.Compare(a, key);
 }

 Slice MemTableRep::UserKey(const char* key) const {
@@ -70,10 +142,15 @@ Slice MemTableRep::UserKey(const char* key) const {
  return Slice(slice.data(), slice.size() - 8);
 }

+KeyHandle MemTableRep::Allocate(const size_t len, char** buf) {
+  *buf = arena_->Allocate(len);
+  return static_cast<KeyHandle>(*buf);
+}
+
 // Encode a suitable internal key target for "target" and return it.
 // Uses *scratch as scratch space, and the returned pointer will point
 // into this scratch space.
-static const char* EncodeKey(std::string* scratch, const Slice& target) {
+const char* EncodeKey(std::string* scratch, const Slice& target) {
  scratch->clear();
  PutVarint32(scratch, target.size());
  scratch->append(target.data(), target.size());
@@ -82,27 +159,55 @@ static const char* EncodeKey(std::string* scratch, const Slice& target) {

 class MemTableIterator: public Iterator {
 public:
-  MemTableIterator(MemTableRep* table, const ReadOptions& options)
-    : iter_() {
+  MemTableIterator(const MemTable& mem, const ReadOptions& options)
+      : bloom_(nullptr),
+        prefix_extractor_(mem.prefix_extractor_),
+        iter_(),
+        valid_(false) {
    if (options.prefix) {
-      iter_.reset(table->GetPrefixIterator(*options.prefix));
+      iter_.reset(mem.table_->GetPrefixIterator(*options.prefix));
    } else if (options.prefix_seek) {
-      iter_.reset(table->GetDynamicPrefixIterator());
+      bloom_ = mem.prefix_bloom_.get();
+      iter_.reset(mem.table_->GetDynamicPrefixIterator());
    } else {
-      iter_.reset(table->GetIterator());
+      iter_.reset(mem.table_->GetIterator());
    }
  }

-  virtual bool Valid() const { return iter_->Valid(); }
-  virtual void Seek(const Slice& k) { iter_->Seek(EncodeKey(&tmp_, k)); }
-  virtual void SeekToFirst() { iter_->SeekToFirst(); }
-  virtual void SeekToLast() { iter_->SeekToLast(); }
-  virtual void Next() { iter_->Next(); }
-  virtual void Prev() { iter_->Prev(); }
+  virtual bool Valid() const { return valid_; }
+  virtual void Seek(const Slice& k) {
+    if (bloom_ != nullptr &&
+        !bloom_->MayContain(prefix_extractor_->Transform(ExtractUserKey(k)))) {
+      valid_ = false;
+      return;
+    }
+    iter_->Seek(k, nullptr);
+    valid_ = iter_->Valid();
+  }
+  virtual void SeekToFirst() {
+    iter_->SeekToFirst();
+    valid_ = iter_->Valid();
+  }
+  virtual void SeekToLast() {
+    iter_->SeekToLast();
+    valid_ = iter_->Valid();
+  }
+  virtual void Next() {
+    assert(Valid());
+    iter_->Next();
+    valid_ = iter_->Valid();
+  }
+  virtual void Prev() {
+    assert(Valid());
+    iter_->Prev();
+    valid_ = iter_->Valid();
+  }
  virtual Slice key() const {
+    assert(Valid());
    return GetLengthPrefixedSlice(iter_->key());
  }
  virtual Slice value() const {
+    assert(Valid());
    Slice key_slice = GetLengthPrefixedSlice(iter_->key());
    return GetLengthPrefixedSlice(key_slice.data() + key_slice.size());
  }
@@ -110,8 +215,10 @@ class MemTableIterator: public Iterator {
  virtual Status status() const { return Status::OK(); }

 private:
-  std::unique_ptr<MemTableRep::Iterator> iter_;
-  std::string tmp_;       // For passing to EncodeKey
+  DynamicBloom* bloom_;
+  const SliceTransform* const prefix_extractor_;
+  std::shared_ptr<MemTableRep::Iterator> iter_;
+  bool valid_;

  // No copying allowed
  MemTableIterator(const MemTableIterator&);
@@ -119,15 +226,16 @@ class MemTableIterator: public Iterator {
 };

 Iterator* MemTable::NewIterator(const ReadOptions& options) {
-  return new MemTableIterator(table_.get(), options);
+  return new MemTableIterator(*this, options);
 }

 port::RWMutex* MemTable::GetLock(const Slice& key) {
-  return &locks_[std::hash<Slice>()(key) % locks_.size()];
+  static murmur_hash hash;
+  return &locks_[hash(key) % locks_.size()];
 }

 void MemTable::Add(SequenceNumber s, ValueType type,
-                   const Slice& key,
+                   const Slice& key, /* user key */
                   const Slice& value) {
  // Format of an entry is concatenation of:
  //  key_size     : varint32 of internal_key.size()
@@ -140,7 +248,9 @@ void MemTable::Add(SequenceNumber s, ValueType type,
  const size_t encoded_len =
      VarintLength(internal_key_size) + internal_key_size +
      VarintLength(val_size) + val_size;
-  char* buf = arena_impl_.Allocate(encoded_len);
+  char* buf = nullptr;
+  KeyHandle handle = table_->Allocate(encoded_len, &buf);
+  assert(buf != nullptr);
  char* p = EncodeVarint32(buf, internal_key_size);
  memcpy(p, key.data(), key_size);
  p += key_size;
@@ -148,132 +258,174 @@ void MemTable::Add(SequenceNumber s, ValueType type,
  p += 8;
  p = EncodeVarint32(p, val_size);
  memcpy(p, value.data(), val_size);
-  assert((p + val_size) - buf == (unsigned)encoded_len);
-  table_->Insert(buf);
+  assert((unsigned)(p + val_size - buf) == (unsigned)encoded_len);
+  table_->Insert(handle);
+
+  if (prefix_bloom_) {
+    assert(prefix_extractor_);
+    prefix_bloom_->Add(prefix_extractor_->Transform(key));
+  }

  // The first sequence number inserted into the memtable
  assert(first_seqno_ == 0 || s > first_seqno_);
  if (first_seqno_ == 0) {
    first_seqno_ = s;
  }
+
+  should_flush_ = ShouldFlushNow();
+}
+
+// Callback from MemTable::Get()
+namespace {
+
+struct Saver {
+  Status* status;
+  const LookupKey* key;
+  bool* found_final_value;  // Is value set correctly? Used by KeyMayExist
+  bool* merge_in_progress;
+  std::string* value;
+  const MergeOperator* merge_operator;
+  // the merge operations encountered;
+  MergeContext* merge_context;
+  MemTable* mem;
+  Logger* logger;
+  Statistics* statistics;
+  bool inplace_update_support;
+};
+}  // namespace
+
+static bool SaveValue(void* arg, const char* entry) {
+  Saver* s = reinterpret_cast<Saver*>(arg);
+  MergeContext* merge_context = s->merge_context;
+  const MergeOperator* merge_operator = s->merge_operator;
+
+  assert(s != nullptr && merge_context != nullptr);
+
+  // entry format is:
+  //    klength  varint32
+  //    userkey  char[klength-8]
+  //    tag      uint64
+  //    vlength  varint32
+  //    value    char[vlength]
+  // Check that it belongs to same user key.  We do not check the
+  // sequence number since the Seek() call above should have skipped
+  // all entries with overly large sequence numbers.
+  uint32_t key_length;
+  const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
+  if (s->mem->GetInternalKeyComparator().user_comparator()->Compare(
+          Slice(key_ptr, key_length - 8), s->key->user_key()) == 0) {
+    // Correct user key
+    const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
+    switch (static_cast<ValueType>(tag & 0xff)) {
+      case kTypeValue: {
+        if (s->inplace_update_support) {
+          s->mem->GetLock(s->key->user_key())->ReadLock();
+        }
+        Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
+        *(s->status) = Status::OK();
+        if (*(s->merge_in_progress)) {
+          assert(merge_operator);
+          if (!merge_operator->FullMerge(s->key->user_key(), &v,
+                                         merge_context->GetOperands(), s->value,
+                                         s->logger)) {
+            RecordTick(s->statistics, NUMBER_MERGE_FAILURES);
+            *(s->status) =
+                Status::Corruption("Error: Could not perform merge.");
+          }
+        } else {
+          s->value->assign(v.data(), v.size());
+        }
+        if (s->inplace_update_support) {
+          s->mem->GetLock(s->key->user_key())->Unlock();
+        }
+        *(s->found_final_value) = true;
+        return false;
+      }
+      case kTypeDeletion: {
+        if (*(s->merge_in_progress)) {
+          assert(merge_operator);
+          *(s->status) = Status::OK();
+          if (!merge_operator->FullMerge(s->key->user_key(), nullptr,
+                                         merge_context->GetOperands(), s->value,
+                                         s->logger)) {
+            RecordTick(s->statistics, NUMBER_MERGE_FAILURES);
+            *(s->status) =
+                Status::Corruption("Error: Could not perform merge.");
+          }
+        } else {
+          *(s->status) = Status::NotFound();
+        }
+        *(s->found_final_value) = true;
+        return false;
+      }
+      case kTypeMerge: {
+        std::string merge_result;  // temporary area for merge results later
+        Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
+        *(s->merge_in_progress) = true;
+        merge_context->PushOperand(v);
+        return true;
+      }
+      default:
+        assert(false);
+        return true;
+    }
+  }
+
+  // s->state could be Corrupt, merge or notfound
+  return false;
 }

 bool MemTable::Get(const LookupKey& key, std::string* value, Status* s,
                   MergeContext& merge_context, const Options& options) {
-  Slice memkey = key.memtable_key();
-  std::unique_ptr<MemTableRep::Iterator> iter(
-      table_->GetIterator(key.user_key()));
-  iter->Seek(memkey.data());
+  StopWatchNano memtable_get_timer(options.env, false);
+  StartPerfTimer(&memtable_get_timer);

+  Slice user_key = key.user_key();
+  bool found_final_value = false;
  bool merge_in_progress = s->IsMergeInProgress();
-  auto merge_operator = options.merge_operator.get();
-  auto logger = options.info_log;
-  std::string merge_result;

-  for (; iter->Valid(); iter->Next()) {
-    // entry format is:
-    //    klength  varint32
-    //    userkey  char[klength-8]
-    //    tag      uint64
-    //    vlength  varint32
-    //    value    char[vlength]
-    // Check that it belongs to same user key.  We do not check the
-    // sequence number since the Seek() call above should have skipped
-    // all entries with overly large sequence numbers.
-    const char* entry = iter->key();
-    uint32_t key_length;
-    const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
-    if (comparator_.comparator.user_comparator()->Compare(
-        Slice(key_ptr, key_length - 8), key.user_key()) == 0) {
-      // Correct user key
-      const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
-      switch (static_cast<ValueType>(tag & 0xff)) {
-        case kTypeValue: {
-          if (options.inplace_update_support) {
-            GetLock(key.user_key())->ReadLock();
-          }
-          Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
-          *s = Status::OK();
-          if (merge_in_progress) {
-            assert(merge_operator);
-          if (!merge_operator->FullMerge(key.user_key(), &v,
-                                         merge_context.GetOperands(), value,
-                                         logger.get())) {
-              RecordTick(options.statistics.get(), NUMBER_MERGE_FAILURES);
-              *s = Status::Corruption("Error: Could not perform merge.");
-            }
-          } else {
-            value->assign(v.data(), v.size());
-          }
-          if (options.inplace_update_support) {
-            GetLock(key.user_key())->Unlock();
-          }
-          return true;
-        }
-        case kTypeDeletion: {
-          if (merge_in_progress) {
-            assert(merge_operator);
-            *s = Status::OK();
-          if (!merge_operator->FullMerge(key.user_key(), nullptr,
-                                         merge_context.GetOperands(), value,
-                                         logger.get())) {
-              RecordTick(options.statistics.get(), NUMBER_MERGE_FAILURES);
-              *s = Status::Corruption("Error: Could not perform merge.");
-            }
-          } else {
-            *s = Status::NotFound();
-          }
-          return true;
-        }
-        case kTypeMerge: {
-          Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
-          merge_in_progress = true;
-          merge_context.PushOperand(v);
-          while(merge_context.GetNumOperands() >= 2) {
-            // Attempt to associative merge. (Returns true if successful)
-          if (merge_operator->PartialMerge(key.user_key(),
-                                           merge_context.GetOperand(0),
-                                           merge_context.GetOperand(1),
-                                           &merge_result, logger.get())) {
-              merge_context.PushPartialMergeResult(merge_result);
-            } else {
-              // Stack them because user can't associative merge
-              break;
-            }
-          }
-          break;
-        }
-        case kTypeLogData:
-          assert(false);
-          break;
-      }
-    } else {
-      // exit loop if user key does not match
-      break;
-    }
+  if (prefix_bloom_ &&
+      !prefix_bloom_->MayContain(prefix_extractor_->Transform(user_key))) {
+    // iter is null if prefix bloom says the key does not exist
+  } else {
+    Saver saver;
+    saver.status = s;
+    saver.found_final_value = &found_final_value;
+    saver.merge_in_progress = &merge_in_progress;
+    saver.key = &key;
+    saver.value = value;
+    saver.status = s;
+    saver.mem = this;
+    saver.merge_context = &merge_context;
+    saver.merge_operator = options.merge_operator.get();
+    saver.logger = options.info_log.get();
+    saver.inplace_update_support = options.inplace_update_support;
+    saver.statistics = options.statistics.get();
+    table_->Get(key, &saver, SaveValue);
  }

  // No change to value, since we have not yet found a Put/Delete
-
-  if (merge_in_progress) {
+  if (!found_final_value && merge_in_progress) {
    *s = Status::MergeInProgress("");
  }
-  return false;
+  BumpPerfTime(&perf_context.get_from_memtable_time, &memtable_get_timer);
+  BumpPerfCount(&perf_context.get_from_memtable_count);
+  return found_final_value;
 }

-bool MemTable::Update(SequenceNumber seq, ValueType type,
+void MemTable::Update(SequenceNumber seq,
                      const Slice& key,
                      const Slice& value) {
  LookupKey lkey(key, seq);
-  Slice memkey = lkey.memtable_key();
+  Slice mem_key = lkey.memtable_key();

  std::unique_ptr<MemTableRep::Iterator> iter(
-      table_->GetIterator(lkey.user_key()));
-  iter->Seek(memkey.data());
+    table_->GetIterator(lkey.user_key()));
+  iter->Seek(lkey.internal_key(), mem_key.data());

  if (iter->Valid()) {
    // entry format is:
-    //    klength  varint32
+    //    key_length  varint32
    //    userkey  char[klength-8]
    //    tag      uint64
    //    vlength  varint32
@@ -282,7 +434,7 @@ bool MemTable::Update(SequenceNumber seq, ValueType type,
    // sequence number since the Seek() call above should have skipped
    // all entries with overly large sequence numbers.
    const char* entry = iter->key();
-    uint32_t key_length;
+    uint32_t key_length = 0;
    const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
    if (comparator_.comparator.user_comparator()->Compare(
        Slice(key_ptr, key_length - 8), lkey.user_key()) == 0) {
@@ -290,36 +442,108 @@ bool MemTable::Update(SequenceNumber seq, ValueType type,
      const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
      switch (static_cast<ValueType>(tag & 0xff)) {
        case kTypeValue: {
-          uint32_t vlength;
-          GetVarint32Ptr(key_ptr + key_length,
-                         key_ptr + key_length+5, &vlength);
-          // Update value, if newValue size  <= curValue size
-          if (value.size() <= vlength) {
+          Slice prev_value = GetLengthPrefixedSlice(key_ptr + key_length);
+          uint32_t prev_size = prev_value.size();
+          uint32_t new_size = value.size();
+
+          // Update value, if new value size  <= previous value size
+          if (new_size <= prev_size ) {
            char* p = EncodeVarint32(const_cast<char*>(key_ptr) + key_length,
-                                     value.size());
+                                     new_size);
            WriteLock wl(GetLock(lkey.user_key()));
            memcpy(p, value.data(), value.size());
-            assert(
-              (p + value.size()) - entry ==
-              (unsigned) (VarintLength(key_length) +
-                          key_length +
-                          VarintLength(value.size()) +
-                          value.size())
-            );
-            return true;
+            assert((unsigned)((p + value.size()) - entry) ==
+                   (unsigned)(VarintLength(key_length) + key_length +
+                              VarintLength(value.size()) + value.size()));
+            return;
          }
        }
        default:
          // If the latest value is kTypeDeletion, kTypeMerge or kTypeLogData
-          // then we probably don't have enough space to update in-place
-          // Maybe do something later
-          // Return false, and do normal Add()
-          return false;
+          // we don't have enough space for update inplace
+            Add(seq, kTypeValue, key, value);
+            return;
      }
    }
  }

-  // Key doesn't exist
+  // key doesn't exist
+  Add(seq, kTypeValue, key, value);
+}
+
+bool MemTable::UpdateCallback(SequenceNumber seq,
+                              const Slice& key,
+                              const Slice& delta,
+                              const Options& options) {
+  LookupKey lkey(key, seq);
+  Slice memkey = lkey.memtable_key();
+
+  std::shared_ptr<MemTableRep::Iterator> iter(
+    table_->GetIterator(lkey.user_key()));
+  iter->Seek(lkey.internal_key(), memkey.data());
+
+  if (iter->Valid()) {
+    // entry format is:
+    //    key_length  varint32
+    //    userkey  char[klength-8]
+    //    tag      uint64
+    //    vlength  varint32
+    //    value    char[vlength]
+    // Check that it belongs to same user key.  We do not check the
+    // sequence number since the Seek() call above should have skipped
+    // all entries with overly large sequence numbers.
+    const char* entry = iter->key();
+    uint32_t key_length = 0;
+    const char* key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
+    if (comparator_.comparator.user_comparator()->Compare(
+        Slice(key_ptr, key_length - 8), lkey.user_key()) == 0) {
+      // Correct user key
+      const uint64_t tag = DecodeFixed64(key_ptr + key_length - 8);
+      switch (static_cast<ValueType>(tag & 0xff)) {
+        case kTypeValue: {
+          Slice prev_value = GetLengthPrefixedSlice(key_ptr + key_length);
+          uint32_t  prev_size = prev_value.size();
+
+          char* prev_buffer = const_cast<char*>(prev_value.data());
+          uint32_t  new_prev_size = prev_size;
+
+          std::string str_value;
+          WriteLock wl(GetLock(lkey.user_key()));
+          auto status = options.inplace_callback(prev_buffer, &new_prev_size,
+                                                    delta, &str_value);
+          if (status == UpdateStatus::UPDATED_INPLACE) {
+            // Value already updated by callback.
+            assert(new_prev_size <= prev_size);
+            if (new_prev_size < prev_size) {
+              // overwrite the new prev_size
+              char* p = EncodeVarint32(const_cast<char*>(key_ptr) + key_length,
+                                       new_prev_size);
+              if (VarintLength(new_prev_size) < VarintLength(prev_size)) {
+                // shift the value buffer as well.
+                memcpy(p, prev_buffer, new_prev_size);
+              }
+            }
+            RecordTick(options.statistics.get(), NUMBER_KEYS_UPDATED);
+            should_flush_ = ShouldFlushNow();
+            return true;
+          } else if (status == UpdateStatus::UPDATED) {
+            Add(seq, kTypeValue, key, Slice(str_value));
+            RecordTick(options.statistics.get(), NUMBER_KEYS_WRITTEN);
+            should_flush_ = ShouldFlushNow();
+            return true;
+          } else if (status == UpdateStatus::UPDATE_FAILED) {
+            // No action required. Return.
+            should_flush_ = ShouldFlushNow();
+            return true;
+          }
+        }
+        default:
+          break;
+      }
+    }
+  }
+  // If the latest value is not kTypeValue
+  // or key doesn't exist
  return false;
 }

@@ -331,16 +555,16 @@ size_t MemTable::CountSuccessiveMergeEntries(const LookupKey& key) {
  // The iterator only needs to be ordered within the same user key.
  std::unique_ptr<MemTableRep::Iterator> iter(
      table_->GetIterator(key.user_key()));
-  iter->Seek(memkey.data());
+  iter->Seek(key.internal_key(), memkey.data());

  size_t num_successive_merges = 0;

  for (; iter->Valid(); iter->Next()) {
    const char* entry = iter->key();
-    uint32_t key_length;
+    uint32_t key_length = 0;
    const char* iter_key_ptr = GetVarint32Ptr(entry, entry + 5, &key_length);
-    if (!comparator_.comparator.user_comparator()->Compare(
-        Slice(iter_key_ptr, key_length - 8), key.user_key()) == 0) {
+    if (comparator_.comparator.user_comparator()->Compare(
+            Slice(iter_key_ptr, key_length - 8), key.user_key()) != 0) {
      break;
    }

@@ -355,4 +579,13 @@ size_t MemTable::CountSuccessiveMergeEntries(const LookupKey& key) {
  return num_successive_merges;
 }

+void MemTableRep::Get(const LookupKey& k, void* callback_args,
+                      bool (*callback_func)(void* arg, const char* entry)) {
+  auto iter = GetIterator(k.user_key());
+  for (iter->Seek(k.internal_key(), k.memtable_key().data());
+       iter->Valid() && callback_func(callback_args, iter->key());
+       iter->Next()) {
+  }
+}
+
 }  // namespace rocksdb
@@ -16,7 +16,8 @@
 #include "db/version_set.h"
 #include "rocksdb/db.h"
 #include "rocksdb/memtablerep.h"
-#include "util/arena_impl.h"
+#include "util/arena.h"
+#include "util/dynamic_bloom.h"

 namespace rocksdb {

@@ -29,7 +30,10 @@ class MemTable {
  struct KeyComparator : public MemTableRep::KeyComparator {
    const InternalKeyComparator comparator;
    explicit KeyComparator(const InternalKeyComparator& c) : comparator(c) { }
-    virtual int operator()(const char* a, const char* b) const;
+    virtual int operator()(const char* prefix_len_key1,
+                           const char* prefix_len_key2) const;
+    virtual int operator()(const char* prefix_len_key,
+                           const Slice& key) const override;
  };

  // MemTables are reference counted.  The initial reference count
@@ -60,6 +64,10 @@ class MemTable {
  // operations on the same MemTable.
  size_t ApproximateMemoryUsage();

+  // This method heuristically determines if the memtable should continue to
+  // host more data.
+  bool ShouldFlush() const { return should_flush_; }
+
  // Return an iterator that yields the contents of the memtable.
  //
  // The caller must ensure that the underlying MemTable remains live
@@ -94,16 +102,31 @@ class MemTable {
  bool Get(const LookupKey& key, std::string* value, Status* s,
           MergeContext& merge_context, const Options& options);

-  // Update the value and return status ok,
-  //   if key exists in current memtable
-  //     if new sizeof(new_value) <= sizeof(old_value) &&
-  //       old_value for that key is a put i.e. kTypeValue
-  //     else return false, and status - NotUpdatable()
-  //   else return false, and status - NotFound()
-  bool Update(SequenceNumber seq, ValueType type,
+  // Attempts to update the new_value inplace, else does normal Add
+  // Pseudocode
+  //   if key exists in current memtable && prev_value is of type kTypeValue
+  //     if new sizeof(new_value) <= sizeof(prev_value)
+  //       update inplace
+  //     else add(key, new_value)
+  //   else add(key, new_value)
+  void Update(SequenceNumber seq,
              const Slice& key,
              const Slice& value);

+  // If prev_value for key exits, attempts to update it inplace.
+  // else returns false
+  // Pseudocode
+  //   if key exists in current memtable && prev_value is of type kTypeValue
+  //     new_value = delta(prev_value)
+  //     if sizeof(new_value) <= sizeof(prev_value)
+  //       update inplace
+  //     else add(key, new_value)
+  //   else return false
+  bool UpdateCallback(SequenceNumber seq,
+                      const Slice& key,
+                      const Slice& delta,
+                      const Options& options);
+
  // Returns the number of successive merge entries starting from the newest
  // entry for the key up to the last non-merge entry or last entry for the
  // key in the memtable.
@@ -135,14 +158,28 @@ class MemTable {
  // Notify the underlying storage that no more items will be added
  void MarkImmutable() { table_->MarkReadOnly(); }

+  // Get the lock associated for the key
+  port::RWMutex* GetLock(const Slice& key);
+
+  const InternalKeyComparator& GetInternalKeyComparator() const {
+    return comparator_.comparator;
+  }
+
+  const Arena& TEST_GetArena() const { return arena_; }
+
 private:
+  // Dynamically check if we can add more incoming entries.
+  bool ShouldFlushNow() const;
+
  friend class MemTableIterator;
  friend class MemTableBackwardIterator;
  friend class MemTableList;

  KeyComparator comparator_;
  int refs_;
-  ArenaImpl arena_impl_;
+  const size_t kArenaBlockSize;
+  const size_t kWriteBufferSize;
+  Arena arena_;
  unique_ptr<MemTableRep> table_;

  // These are used to manage memtable flushes to storage
@@ -150,7 +187,7 @@ class MemTable {
  bool flush_completed_;   // finished the flush
  uint64_t file_number_;    // filled up after flush is complete

-  // The udpates to be applied to the transaction log when this
+  // The updates to be applied to the transaction log when this
  // memtable is flushed to storage.
  VersionEdit edit_;

@@ -171,8 +208,13 @@ class MemTable {
  MemTable(const MemTable&);
  void operator=(const MemTable&);

-  // Get the lock associated for the key
-  port::RWMutex* GetLock(const Slice& key);
+  const SliceTransform* const prefix_extractor_;
+  std::unique_ptr<DynamicBloom> prefix_bloom_;
+
+  // a flag indicating if a memtable has met the criteria to flush
+  bool should_flush_;
 };

+extern const char* EncodeKey(std::string* scratch, const Slice& target);
+
 }  // namespace rocksdb
@@ -3,7 +3,7 @@
 //  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.
 //
-#include "db/memtablelist.h"
+#include "db/memtable_list.h"

 #include <string>
 #include "rocksdb/db.h"
@@ -11,6 +11,7 @@
 #include "rocksdb/env.h"
 #include "rocksdb/iterator.h"
 #include "util/coding.h"
+#include "util/log_buffer.h"

 namespace rocksdb {

@@ -30,7 +31,7 @@ MemTableListVersion::MemTableListVersion(MemTableListVersion* old) {

 void MemTableListVersion::Ref() { ++refs_; }

-void MemTableListVersion::Unref(std::vector<MemTable*>* to_delete) {
+void MemTableListVersion::Unref(autovector<MemTable*>* to_delete) {
  assert(refs_ >= 1);
  --refs_;
  if (refs_ == 0) {
@@ -92,7 +93,7 @@ void MemTableListVersion::Remove(MemTable* m) {

 // Returns true if there is at least one memtable on which flush has
 // not yet started.
-bool MemTableList::IsFlushPending() {
+bool MemTableList::IsFlushPending() const {
  if ((flush_requested_ && num_flush_not_started_ >= 1) ||
      (num_flush_not_started_ >= min_write_buffer_number_to_merge_)) {
    assert(imm_flush_needed.NoBarrier_Load() != nullptr);
@@ -102,7 +103,7 @@ bool MemTableList::IsFlushPending() {
 }

 // Returns the memtables that need to be flushed.
-void MemTableList::PickMemtablesToFlush(std::vector<MemTable*>* ret) {
+void MemTableList::PickMemtablesToFlush(autovector<MemTable*>* ret) {
  const auto& memlist = current_->memlist_;
  for (auto it = memlist.rbegin(); it != memlist.rend(); ++it) {
    MemTable* m = *it;
@@ -112,38 +113,40 @@ void MemTableList::PickMemtablesToFlush(std::vector<MemTable*>* ret) {
      if (num_flush_not_started_ == 0) {
        imm_flush_needed.Release_Store(nullptr);
      }
-      m->flush_in_progress_ = true; // flushing will start very soon
+      m->flush_in_progress_ = true;  // flushing will start very soon
      ret->push_back(m);
    }
  }
-  flush_requested_ = false; // start-flush request is complete
+  flush_requested_ = false;  // start-flush request is complete
+}
+
+void MemTableList::RollbackMemtableFlush(const autovector<MemTable*>& mems,
+     uint64_t file_number, std::set<uint64_t>* pending_outputs) {
+  assert(!mems.empty());
+
+  // If the flush was not successful, then just reset state.
+  // Maybe a suceeding attempt to flush will be successful.
+  for (MemTable* m : mems) {
+    assert(m->flush_in_progress_);
+    assert(m->file_number_ == 0);
+
+    m->flush_in_progress_ = false;
+    m->flush_completed_ = false;
+    m->edit_.Clear();
+    num_flush_not_started_++;
+  }
+  pending_outputs->erase(file_number);
+  imm_flush_needed.Release_Store(reinterpret_cast<void *>(1));
 }

 // Record a successful flush in the manifest file
 Status MemTableList::InstallMemtableFlushResults(
-    const std::vector<MemTable*>& mems, VersionSet* vset, Status flushStatus,
-    port::Mutex* mu, Logger* info_log, uint64_t file_number,
-    std::set<uint64_t>& pending_outputs, std::vector<MemTable*>* to_delete,
-    Directory* db_directory) {
+    const autovector<MemTable*>& mems, VersionSet* vset, port::Mutex* mu,
+    Logger* info_log, uint64_t file_number, std::set<uint64_t>& pending_outputs,
+    autovector<MemTable*>* to_delete, Directory* db_directory,
+    LogBuffer* log_buffer) {
  mu->AssertHeld();

-  // If the flush was not successful, then just reset state.
-  // Maybe a suceeding attempt to flush will be successful.
-  if (!flushStatus.ok()) {
-    for (MemTable* m : mems) {
-      assert(m->flush_in_progress_);
-      assert(m->file_number_ == 0);
-
-      m->flush_in_progress_ = false;
-      m->flush_completed_ = false;
-      m->edit_.Clear();
-      num_flush_not_started_++;
-      imm_flush_needed.Release_Store((void *)1);
-      pending_outputs.erase(file_number);
-    }
-    return flushStatus;
-  }
-
  // flush was sucessful
  for (size_t i = 0; i < mems.size(); ++i) {
    // All the edits are associated with the first memtable of this batch.
@@ -171,9 +174,8 @@ Status MemTableList::InstallMemtableFlushResults(
      break;
    }

-    Log(info_log,
-        "Level-0 commit table #%lu started",
-        (unsigned long)m->file_number_);
+    LogToBuffer(log_buffer, "Level-0 commit table #%lu started",
+                (unsigned long)m->file_number_);

    // this can release and reacquire the mutex.
    s = vset->LogAndApply(&m->edit_, mu, db_directory);
@@ -187,10 +189,8 @@ Status MemTableList::InstallMemtableFlushResults(
    uint64_t mem_id = 1;  // how many memtables has been flushed.
    do {
      if (s.ok()) { // commit new state
-        Log(info_log,
-            "Level-0 commit table #%lu: memtable #%lu done",
-            (unsigned long)m->file_number_,
-            (unsigned long)mem_id);
+        LogToBuffer(log_buffer, "Level-0 commit table #%lu: memtable #%lu done",
+                    (unsigned long)m->file_number_, (unsigned long)mem_id);
        current_->Remove(m);
        assert(m->file_number_ > 0);

@@ -215,7 +215,6 @@ Status MemTableList::InstallMemtableFlushResults(
        pending_outputs.erase(m->file_number_);
        m->file_number_ = 0;
        imm_flush_needed.Release_Store((void *)1);
-        s = Status::IOError("Unable to commit flushed memtable");
      }
      ++mem_id;
    } while (!current_->memlist_.empty() && (m = current_->memlist_.back()) &&
@@ -3,17 +3,20 @@
 //  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.
 //
-
 #pragma once
+
 #include <string>
 #include <list>
-#include <vector>
-#include "rocksdb/db.h"
-#include "rocksdb/options.h"
-#include "rocksdb/iterator.h"
+#include <deque>
+
 #include "db/dbformat.h"
+#include "db/memtable.h"
 #include "db/skiplist.h"
-#include "memtable.h"
+#include "rocksdb/db.h"
+#include "rocksdb/db.h"
+#include "rocksdb/iterator.h"
+#include "rocksdb/options.h"
+#include "util/autovector.h"

 namespace rocksdb {

@@ -28,7 +31,7 @@ class MemTableListVersion {
  explicit MemTableListVersion(MemTableListVersion* old = nullptr);

  void Ref();
-  void Unref(std::vector<MemTable*>* to_delete = nullptr);
+  void Unref(autovector<MemTable*>* to_delete = nullptr);

  int size() const;

@@ -74,8 +77,8 @@ class MemTableList {

  MemTableListVersion* current() { return current_; }

-  // so that backgrund threads can detect non-nullptr pointer to
-  // determine whether this is anything more to start flushing.
+  // so that background threads can detect non-nullptr pointer to
+  // determine whether there is anything more to start flushing.
  port::AtomicPointer imm_flush_needed;

  // Returns the total number of memtables in the list
@@ -83,20 +86,26 @@ class MemTableList {

  // Returns true if there is at least one memtable on which flush has
  // not yet started.
-  bool IsFlushPending();
+  bool IsFlushPending() const;

  // Returns the earliest memtables that needs to be flushed. The returned
  // memtables are guaranteed to be in the ascending order of created time.
-  void PickMemtablesToFlush(std::vector<MemTable*>* mems);
+  void PickMemtablesToFlush(autovector<MemTable*>* mems);
+
+  // Reset status of the given memtable list back to pending state so that
+  // they can get picked up again on the next round of flush.
+  void RollbackMemtableFlush(const autovector<MemTable*>& mems,
+                             uint64_t file_number,
+                             std::set<uint64_t>* pending_outputs);

  // Commit a successful flush in the manifest file
-  Status InstallMemtableFlushResults(const std::vector<MemTable*>& m,
-                                     VersionSet* vset, Status flushStatus,
-                                     port::Mutex* mu, Logger* info_log,
-                                     uint64_t file_number,
+  Status InstallMemtableFlushResults(const autovector<MemTable*>& m,
+                                     VersionSet* vset, port::Mutex* mu,
+                                     Logger* info_log, uint64_t file_number,
                                     std::set<uint64_t>& pending_outputs,
-                                     std::vector<MemTable*>* to_delete,
-                                     Directory* db_directory);
+                                     autovector<MemTable*>* to_delete,
+                                     Directory* db_directory,
+                                     LogBuffer* log_buffer);

  // New memtables are inserted at the front of the list.
  // Takes ownership of the referenced held on *m by the caller of Add().
@@ -25,12 +25,12 @@ public:
      operand_list->clear();
    }
  }
-  // Replace the first two operands of merge_result, which are expected be the
-  // merge results of them.
+  // Replace all operands with merge_result, which are expected to be the
+  // merge result of them.
  void PushPartialMergeResult(std::string& merge_result) {
    assert (operand_list);
-    operand_list->pop_front();
-    swap(operand_list->front(), merge_result);
+    operand_list->clear();
+    operand_list->push_front(std::move(merge_result));
  }
  // Push a merge operand
  void PushOperand(const Slice& operand_slice) {
@@ -21,7 +21,7 @@ namespace rocksdb {
 //       operands_ stores the list of merge operands encountered while merging.
 //       keys_[i] corresponds to operands_[i] for each i.
 void MergeHelper::MergeUntil(Iterator* iter, SequenceNumber stop_before,
-                             bool at_bottom, Statistics* stats) {
+                             bool at_bottom, Statistics* stats, int* steps) {
  // Get a copy of the internal key, before it's invalidated by iter->Next()
  // Also maintain the list of merge operands seen.
  keys_.clear();
@@ -40,9 +40,12 @@ void MergeHelper::MergeUntil(Iterator* iter, SequenceNumber stop_before,
  ParseInternalKey(keys_.back(), &orig_ikey);

  bool hit_the_next_user_key = false;
-  ParsedInternalKey ikey;
  std::string merge_result;  // Temporary value for merge results
+  if (steps) {
+    ++(*steps);
+  }
  for (iter->Next(); iter->Valid(); iter->Next()) {
+    ParsedInternalKey ikey;
    assert(operands_.size() >= 1);        // Should be invariants!
    assert(keys_.size() == operands_.size());

@@ -91,6 +94,9 @@ void MergeHelper::MergeUntil(Iterator* iter, SequenceNumber stop_before,

      // move iter to the next entry (before doing anything else)
      iter->Next();
+      if (steps) {
+        ++(*steps);
+      }
      return;
    }

@@ -119,6 +125,9 @@ void MergeHelper::MergeUntil(Iterator* iter, SequenceNumber stop_before,

      // move iter to the next entry
      iter->Next();
+      if (steps) {
+        ++(*steps);
+      }
      return;
    }

@@ -129,28 +138,13 @@ void MergeHelper::MergeUntil(Iterator* iter, SequenceNumber stop_before,
      //   => then continue because we haven't yet seen a Put/Delete.
      assert(!operands_.empty()); // Should have at least one element in it

+      // keep queuing keys and operands until we either meet a put / delete
+      // request or later did a partial merge.
      keys_.push_front(iter->key().ToString());
      operands_.push_front(iter->value().ToString());
-      while (operands_.size() >= 2) {
-        // Returns false when the merge_operator can no longer process it
-        if (user_merge_operator_->PartialMerge(ikey.user_key,
-                                               Slice(operands_[0]),
-                                               Slice(operands_[1]),
-                                               &merge_result,
-                                               logger_)) {
-          // Merging of operands (associative merge) was successful.
-          // Replace these frontmost two operands with the merge result
-          keys_.pop_front();
-          operands_.pop_front();
-          swap(operands_.front(), merge_result);
-        } else {
-          // Merging of operands (associative merge) returned false.
-          // The user merge_operator does not know how to merge these operands.
-          // So we just stack them up until we find a Put/Delete or end of key.
-          break;
-        }
+      if (steps) {
+        ++(*steps);
      }
-      continue;
    }
  }

@@ -192,6 +186,23 @@ void MergeHelper::MergeUntil(Iterator* iter, SequenceNumber stop_before,
      RecordTick(stats, NUMBER_MERGE_FAILURES);
      // Do nothing if not success_. Leave keys() and operands() as they are.
    }
+  } else {
+    // We haven't seen the beginning of the key nor a Put/Delete.
+    // Attempt to use the user's associative merge function to
+    // merge the stacked merge operands into a single operand.
+
+    if (operands_.size() >= 2 &&
+        operands_.size() >= min_partial_merge_operands_ &&
+        user_merge_operator_->PartialMergeMulti(
+            orig_ikey.user_key,
+            std::deque<Slice>(operands_.begin(), operands_.end()),
+            &merge_result, logger_)) {
+      // Merging of operands (associative merge) was successful.
+      // Replace operands with the merge result
+      operands_.clear();
+      operands_.push_front(std::move(merge_result));
+      keys_.erase(keys_.begin(), keys_.end() - 1);
+    }
  }
 }

@@ -22,12 +22,13 @@ class Statistics;
 class MergeHelper {
 public:
  MergeHelper(const Comparator* user_comparator,
-              const MergeOperator* user_merge_operator,
-              Logger* logger,
+              const MergeOperator* user_merge_operator, Logger* logger,
+              unsigned min_partial_merge_operands,
              bool assert_valid_internal_key)
      : user_comparator_(user_comparator),
        user_merge_operator_(user_merge_operator),
        logger_(logger),
+        min_partial_merge_operands_(min_partial_merge_operands),
        assert_valid_internal_key_(assert_valid_internal_key),
        keys_(),
        operands_(),
@@ -46,7 +47,8 @@ class MergeHelper {
  // at_bottom:   (IN) true if the iterator covers the bottem level, which means
  //                   we could reach the start of the history of this user key.
  void MergeUntil(Iterator* iter, SequenceNumber stop_before = 0,
-                  bool at_bottom = false, Statistics* stats = nullptr);
+                  bool at_bottom = false, Statistics* stats = nullptr,
+                  int* steps = nullptr);

  // Query the merge result
  // These are valid until the next MergeUntil call
@@ -88,6 +90,7 @@ class MergeHelper {
  const Comparator* user_comparator_;
  const MergeOperator* user_merge_operator_;
  Logger* logger_;
+  unsigned min_partial_merge_operands_;
  bool assert_valid_internal_key_; // enforce no internal key corruption?

  // the scratch area that holds the result of MergeUntil
@@ -11,6 +11,31 @@

 namespace rocksdb {

+// The default implementation of PartialMergeMulti, which invokes
+// PartialMerge multiple times internally and merges two operands at
+// a time.
+bool MergeOperator::PartialMergeMulti(const Slice& key,
+                                      const std::deque<Slice>& operand_list,
+                                      std::string* new_value,
+                                      Logger* logger) const {
+  assert(operand_list.size() >= 2);
+  // Simply loop through the operands
+  std::string temp_value;
+  Slice temp_slice(operand_list[0]);
+
+  for (size_t i = 1; i < operand_list.size(); ++i) {
+    auto& operand = operand_list[i];
+    if (!PartialMerge(key, temp_slice, operand, &temp_value, logger)) {
+      return false;
+    }
+    swap(temp_value, *new_value);
+    temp_slice = Slice(*new_value);
+  }
+
+  // The result will be in *new_value. All merges succeeded.
+  return true;
+}
+
 // Given a "real" merge from the library, call the user's
 // associative merge function one-by-one on each of the operands.
 // NOTE: It is assumed that the client's merge-operator will handle any errors.
@@ -46,7 +71,6 @@ bool AssociativeMergeOperator::PartialMerge(
    const Slice& right_operand,
    std::string* new_value,
    Logger* logger) const {
-
  return Merge(key, &left_operand, right_operand, new_value, logger);
 }

@@ -24,10 +24,14 @@ using namespace rocksdb;

 namespace {
  int numMergeOperatorCalls;
-
  void resetNumMergeOperatorCalls() {
    numMergeOperatorCalls = 0;
  }
+
+  int num_partial_merge_calls;
+  void resetNumPartialMergeCalls() {
+    num_partial_merge_calls = 0;
+  }
 }

 class CountMergeOperator : public AssociativeMergeOperator {
@@ -42,6 +46,11 @@ class CountMergeOperator : public AssociativeMergeOperator {
                     std::string* new_value,
                     Logger* logger) const override {
    ++numMergeOperatorCalls;
+    if (existing_value == nullptr) {
+      new_value->assign(value.data(), value.size());
+      return true;
+    }
+
    return mergeOperator_->PartialMerge(
        key,
        *existing_value,
@@ -50,6 +59,14 @@ class CountMergeOperator : public AssociativeMergeOperator {
        logger);
  }

+  virtual bool PartialMergeMulti(const Slice& key,
+                                 const std::deque<Slice>& operand_list,
+                                 std::string* new_value, Logger* logger) const {
+    ++num_partial_merge_calls;
+    return mergeOperator_->PartialMergeMulti(key, operand_list, new_value,
+                                             logger);
+  }
+
  virtual const char* Name() const override {
    return "UInt64AddOperator";
  }
@@ -58,16 +75,16 @@ class CountMergeOperator : public AssociativeMergeOperator {
  std::shared_ptr<MergeOperator> mergeOperator_;
 };

-std::shared_ptr<DB> OpenDb(
-    const string& dbname,
-    const bool ttl = false,
-    const unsigned max_successive_merges = 0) {
+std::shared_ptr<DB> OpenDb(const string& dbname, const bool ttl = false,
+                           const size_t max_successive_merges = 0,
+                           const uint32_t min_partial_merge_operands = 2) {
  DB* db;
  StackableDB* sdb;
  Options options;
  options.create_if_missing = true;
  options.merge_operator = std::make_shared<CountMergeOperator>();
  options.max_successive_merges = max_successive_merges;
+  options.min_partial_merge_operands = min_partial_merge_operands;
  Status s;
  DestroyDB(dbname, Options());
  if (ttl) {
@@ -306,6 +323,44 @@ void testSuccessiveMerge(
  }
 }

+void testPartialMerge(Counters* counters, DB* db, int max_merge, int min_merge,
+                      int count) {
+  FlushOptions o;
+  o.wait = true;
+
+  // Test case 1: partial merge should be called when the number of merge
+  //              operands exceeds the threshold.
+  uint64_t tmp_sum = 0;
+  resetNumPartialMergeCalls();
+  for (int i = 1; i <= count; i++) {
+    counters->assert_add("b", i);
+    tmp_sum += i;
+  }
+  db->Flush(o);
+  db->CompactRange(nullptr, nullptr);
+  ASSERT_EQ(tmp_sum, counters->assert_get("b"));
+  if (count > max_merge) {
+    // in this case, FullMerge should be called instead.
+    ASSERT_EQ(num_partial_merge_calls, 0);
+  } else {
+    // if count >= min_merge, then partial merge should be called once.
+    ASSERT_EQ((count >= min_merge), (num_partial_merge_calls == 1));
+  }
+
+  // Test case 2: partial merge should not be called when a put is found.
+  resetNumPartialMergeCalls();
+  tmp_sum = 0;
+  db->Put(rocksdb::WriteOptions(), "c", "10");
+  for (int i = 1; i <= count; i++) {
+    counters->assert_add("c", i);
+    tmp_sum += i;
+  }
+  db->Flush(o);
+  db->CompactRange(nullptr, nullptr);
+  ASSERT_EQ(tmp_sum, counters->assert_get("c"));
+  ASSERT_EQ(num_partial_merge_calls, 0);
+}
+
 void testSingleBatchSuccessiveMerge(
    DB* db,
    int max_num_merges,
@@ -370,20 +425,40 @@ void runTest(int argc, const string& dbname, const bool use_ttl = false) {

  {
    cout << "Test merge in memtable... \n";
-    unsigned maxMerge = 5;
-    auto db = OpenDb(dbname, use_ttl, maxMerge);
+    size_t max_merge = 5;
+    auto db = OpenDb(dbname, use_ttl, max_merge);
    MergeBasedCounters counters(db, 0);
    testCounters(counters, db.get(), compact);
-    testSuccessiveMerge(counters, maxMerge, maxMerge * 2);
+    testSuccessiveMerge(counters, max_merge, max_merge * 2);
    testSingleBatchSuccessiveMerge(db.get(), 5, 7);
    DestroyDB(dbname, Options());
  }

+  {
+    cout << "Test Partial-Merge\n";
+    size_t max_merge = 100;
+    for (uint32_t min_merge = 5; min_merge < 25; min_merge += 5) {
+      for (uint32_t count = min_merge - 1; count <= min_merge + 1; count++) {
+        auto db = OpenDb(dbname, use_ttl, max_merge, min_merge);
+        MergeBasedCounters counters(db, 0);
+        testPartialMerge(&counters, db.get(), max_merge, min_merge, count);
+        DestroyDB(dbname, Options());
+      }
+      {
+        auto db = OpenDb(dbname, use_ttl, max_merge, min_merge);
+        MergeBasedCounters counters(db, 0);
+        testPartialMerge(&counters, db.get(), max_merge, min_merge,
+                         min_merge * 10);
+        DestroyDB(dbname, Options());
+      }
+    }
+  }
 }

 int main(int argc, char *argv[]) {
  //TODO: Make this test like a general rocksdb unit-test
  runTest(argc, test::TmpDir() + "/merge_testdb");
  runTest(argc, test::TmpDir() + "/merge_testdbttl", true); // Run test on TTL database
+  printf("Passed all tests!\n");
  return 0;
 }
@@ -10,6 +10,8 @@

 #include "rocksdb/db.h"
 #include "rocksdb/perf_context.h"
+#include "rocksdb/slice_transform.h"
+#include "rocksdb/memtablerep.h"
 #include "util/histogram.h"
 #include "util/stop_watch.h"
 #include "util/testharness.h"
@@ -174,6 +176,13 @@ void ProfileKeyComparison() {

  HistogramImpl hist_put;
  HistogramImpl hist_get;
+  HistogramImpl hist_get_snapshot;
+  HistogramImpl hist_get_memtable;
+  HistogramImpl hist_get_post_process;
+  HistogramImpl hist_num_memtable_checked;
+  HistogramImpl hist_write_pre_post;
+  HistogramImpl hist_write_wal_time;
+  HistogramImpl hist_write_memtable_time;

  std::cout << "Inserting " << FLAGS_total_keys << " key/value pairs\n...\n";

@@ -192,16 +201,37 @@ void ProfileKeyComparison() {

    perf_context.Reset();
    db->Put(write_options, key, value);
+    hist_write_pre_post.Add(perf_context.write_pre_and_post_process_time);
+    hist_write_wal_time.Add(perf_context.write_wal_time);
+    hist_write_memtable_time.Add(perf_context.write_memtable_time);
    hist_put.Add(perf_context.user_key_comparison_count);

    perf_context.Reset();
    db->Get(read_options, key, &value);
+    hist_get_snapshot.Add(perf_context.get_snapshot_time);
+    hist_get_memtable.Add(perf_context.get_from_memtable_time);
+    hist_num_memtable_checked.Add(perf_context.get_from_memtable_count);
+    hist_get_post_process.Add(perf_context.get_post_process_time);
    hist_get.Add(perf_context.user_key_comparison_count);
  }

  std::cout << "Put uesr key comparison: \n" << hist_put.ToString()
            << "Get uesr key comparison: \n" << hist_get.ToString();
+  std::cout << "Put(): Pre and Post Process Time: \n"
+            << hist_write_pre_post.ToString()
+            << " Writing WAL time: \n"
+            << hist_write_wal_time.ToString() << "\n"
+            << " Writing Mem Table time: \n"
+            << hist_write_memtable_time.ToString() << "\n";

+  std::cout << "Get(): Time to get snapshot: \n"
+            << hist_get_snapshot.ToString()
+            << " Time to get value from memtables: \n"
+            << hist_get_memtable.ToString() << "\n"
+            << " Number of memtables checked: \n"
+            << hist_num_memtable_checked.ToString() << "\n"
+            << " Time to post process: \n"
+            << hist_get_post_process.ToString() << "\n";
 }

 TEST(PerfContextTest, KeyComparisonCount) {
@@ -259,8 +289,8 @@ TEST(PerfContextTest, SeekKeyComparison) {
    db->Put(write_options, key, value);
    auto put_time = timer.ElapsedNanos();
    hist_put_time.Add(put_time);
-    hist_wal_time.Add(perf_context.wal_write_time);
-    hist_time_diff.Add(put_time - perf_context.wal_write_time);
+    hist_wal_time.Add(perf_context.write_wal_time);
+    hist_time_diff.Add(put_time - perf_context.write_wal_time);
  }

  std::cout << "Put time:\n" << hist_put_time.ToString()
@@ -0,0 +1,780 @@
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//  Copyright (c) 2013, 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.
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+#include <algorithm>
+#include <set>
+
+#include "db/db_impl.h"
+#include "db/filename.h"
+#include "db/version_set.h"
+#include "db/write_batch_internal.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/compaction_filter.h"
+#include "rocksdb/db.h"
+#include "rocksdb/env.h"
+#include "rocksdb/filter_policy.h"
+#include "rocksdb/slice_transform.h"
+#include "rocksdb/table.h"
+#include "table/meta_blocks.h"
+#include "table/plain_table_factory.h"
+#include "table/plain_table_reader.h"
+#include "util/hash.h"
+#include "util/logging.h"
+#include "util/mutexlock.h"
+#include "util/testharness.h"
+#include "util/testutil.h"
+#include "utilities/merge_operators.h"
+
+using std::unique_ptr;
+
+namespace rocksdb {
+
+class PlainTableDBTest {
+ protected:
+ private:
+  std::string dbname_;
+  Env* env_;
+  DB* db_;
+
+  Options last_options_;
+
+ public:
+  PlainTableDBTest() : env_(Env::Default()) {
+    ro_.prefix_seek = true;
+    dbname_ = test::TmpDir() + "/plain_table_db_test";
+    ASSERT_OK(DestroyDB(dbname_, Options()));
+    db_ = nullptr;
+    Reopen();
+  }
+
+  ~PlainTableDBTest() {
+    delete db_;
+    ASSERT_OK(DestroyDB(dbname_, Options()));
+  }
+
+  ReadOptions ro_;
+
+  // Return the current option configuration.
+  Options CurrentOptions() {
+    Options options;
+    options.table_factory.reset(NewPlainTableFactory(16, 2, 0.8, 3));
+    options.prefix_extractor.reset(NewFixedPrefixTransform(8));
+    options.allow_mmap_reads = true;
+    return options;
+  }
+
+  DBImpl* dbfull() {
+    return reinterpret_cast<DBImpl*>(db_);
+  }
+
+  void Reopen(Options* options = nullptr) {
+    ASSERT_OK(TryReopen(options));
+  }
+
+  void Close() {
+    delete db_;
+    db_ = nullptr;
+  }
+
+  void DestroyAndReopen(Options* options = nullptr) {
+    //Destroy using last options
+    Destroy(&last_options_);
+    ASSERT_OK(TryReopen(options));
+  }
+
+  void Destroy(Options* options) {
+    delete db_;
+    db_ = nullptr;
+    ASSERT_OK(DestroyDB(dbname_, *options));
+  }
+
+  Status PureReopen(Options* options, DB** db) {
+    return DB::Open(*options, dbname_, db);
+  }
+
+  Status TryReopen(Options* options = nullptr) {
+    delete db_;
+    db_ = nullptr;
+    Options opts;
+    if (options != nullptr) {
+      opts = *options;
+    } else {
+      opts = CurrentOptions();
+      opts.create_if_missing = true;
+    }
+    last_options_ = opts;
+
+    return DB::Open(opts, dbname_, &db_);
+  }
+
+  Status Put(const Slice& k, const Slice& v) {
+    return db_->Put(WriteOptions(), k, v);
+  }
+
+  Status Delete(const std::string& k) {
+    return db_->Delete(WriteOptions(), k);
+  }
+
+  std::string Get(const std::string& k, const Snapshot* snapshot = nullptr) {
+    ReadOptions options = ro_;
+    options.snapshot = snapshot;
+    std::string result;
+    Status s = db_->Get(options, k, &result);
+    if (s.IsNotFound()) {
+      result = "NOT_FOUND";
+    } else if (!s.ok()) {
+      result = s.ToString();
+    }
+    return result;
+  }
+
+
+  int NumTableFilesAtLevel(int level) {
+    std::string property;
+    ASSERT_TRUE(
+        db_->GetProperty("rocksdb.num-files-at-level" + NumberToString(level),
+                         &property));
+    return atoi(property.c_str());
+  }
+
+  // Return spread of files per level
+  std::string FilesPerLevel() {
+    std::string result;
+    int last_non_zero_offset = 0;
+    for (int level = 0; level < db_->NumberLevels(); level++) {
+      int f = NumTableFilesAtLevel(level);
+      char buf[100];
+      snprintf(buf, sizeof(buf), "%s%d", (level ? "," : ""), f);
+      result += buf;
+      if (f > 0) {
+        last_non_zero_offset = result.size();
+      }
+    }
+    result.resize(last_non_zero_offset);
+    return result;
+  }
+
+  std::string IterStatus(Iterator* iter) {
+    std::string result;
+    if (iter->Valid()) {
+      result = iter->key().ToString() + "->" + iter->value().ToString();
+    } else {
+      result = "(invalid)";
+    }
+    return result;
+  }
+};
+
+TEST(PlainTableDBTest, Empty) {
+  ASSERT_TRUE(dbfull() != nullptr);
+  ASSERT_EQ("NOT_FOUND", Get("0000000000000foo"));
+}
+
+class TestPlainTableReader : public PlainTableReader {
+ public:
+  TestPlainTableReader(const EnvOptions& storage_options,
+                       const InternalKeyComparator& icomparator,
+                       uint64_t file_size, int bloom_bits_per_key,
+                       double hash_table_ratio, size_t index_sparseness,
+                       const TableProperties* table_properties,
+                       unique_ptr<RandomAccessFile>&& file,
+                       const Options& options, bool* expect_bloom_not_match)
+      : PlainTableReader(options, std::move(file), storage_options, icomparator,
+                         file_size, bloom_bits_per_key, hash_table_ratio,
+                         index_sparseness, table_properties),
+        expect_bloom_not_match_(expect_bloom_not_match) {
+    Status s = PopulateIndex();
+    ASSERT_TRUE(s.ok());
+  }
+
+  virtual ~TestPlainTableReader() {}
+
+ private:
+  virtual bool MatchBloom(uint32_t hash) const override {
+    bool ret = PlainTableReader::MatchBloom(hash);
+    ASSERT_TRUE(!*expect_bloom_not_match_ || !ret);
+    return ret;
+  }
+  bool* expect_bloom_not_match_;
+};
+
+extern const uint64_t kPlainTableMagicNumber;
+class TestPlainTableFactory : public PlainTableFactory {
+ public:
+  explicit TestPlainTableFactory(bool* expect_bloom_not_match,
+                                 uint32_t user_key_len =
+                                     kPlainTableVariableLength,
+                                 int bloom_bits_per_key = 0,
+                                 double hash_table_ratio = 0.75,
+                                 size_t index_sparseness = 16)
+      : PlainTableFactory(user_key_len, user_key_len, hash_table_ratio,
+                          hash_table_ratio),
+        bloom_bits_per_key_(bloom_bits_per_key),
+        hash_table_ratio_(hash_table_ratio),
+        index_sparseness_(index_sparseness),
+        expect_bloom_not_match_(expect_bloom_not_match) {}
+
+  Status NewTableReader(const Options& options, const EnvOptions& soptions,
+                        const InternalKeyComparator& internal_comparator,
+                        unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
+                        unique_ptr<TableReader>* table) const override {
+    TableProperties* props = nullptr;
+    auto s = ReadTableProperties(file.get(), file_size, kPlainTableMagicNumber,
+                                 options.env, options.info_log.get(), &props);
+    ASSERT_TRUE(s.ok());
+
+    std::unique_ptr<PlainTableReader> new_reader(new TestPlainTableReader(
+        soptions, internal_comparator, file_size, bloom_bits_per_key_,
+        hash_table_ratio_, index_sparseness_, props, std::move(file), options,
+        expect_bloom_not_match_));
+
+    *table = std::move(new_reader);
+    return s;
+  }
+
+ private:
+  int bloom_bits_per_key_;
+  double hash_table_ratio_;
+  size_t index_sparseness_;
+  bool* expect_bloom_not_match_;
+};
+
+TEST(PlainTableDBTest, Flush) {
+  for (int bloom_bits = 0; bloom_bits <= 117; bloom_bits += 117) {
+    for (int total_order = 0; total_order <= 1; total_order++) {
+      Options options = CurrentOptions();
+      options.create_if_missing = true;
+      // Set only one bucket to force bucket conflict.
+      // Test index interval for the same prefix to be 1, 2 and 4
+      if (total_order) {
+        options.table_factory.reset(
+            NewTotalOrderPlainTableFactory(16, bloom_bits, 2));
+      } else {
+        options.table_factory.reset(NewPlainTableFactory(16, bloom_bits));
+      }
+      DestroyAndReopen(&options);
+
+      ASSERT_OK(Put("1000000000000foo", "v1"));
+      ASSERT_OK(Put("0000000000000bar", "v2"));
+      ASSERT_OK(Put("1000000000000foo", "v3"));
+      dbfull()->TEST_FlushMemTable();
+      ASSERT_EQ("v3", Get("1000000000000foo"));
+      ASSERT_EQ("v2", Get("0000000000000bar"));
+    }
+  }
+}
+
+TEST(PlainTableDBTest, Flush2) {
+  for (int bloom_bits = 0; bloom_bits <= 117; bloom_bits += 117) {
+    for (int total_order = 0; total_order <= 1; total_order++) {
+      bool expect_bloom_not_match = false;
+      Options options = CurrentOptions();
+      options.create_if_missing = true;
+      // Set only one bucket to force bucket conflict.
+      // Test index interval for the same prefix to be 1, 2 and 4
+      if (total_order) {
+        options.prefix_extractor = nullptr;
+        options.table_factory.reset(new TestPlainTableFactory(
+            &expect_bloom_not_match, 16, bloom_bits, 0, 2));
+      } else {
+        options.table_factory.reset(
+            new TestPlainTableFactory(&expect_bloom_not_match, 16, bloom_bits));
+      }
+      DestroyAndReopen(&options);
+      ASSERT_OK(Put("0000000000000bar", "b"));
+      ASSERT_OK(Put("1000000000000foo", "v1"));
+      dbfull()->TEST_FlushMemTable();
+
+      ASSERT_OK(Put("1000000000000foo", "v2"));
+      dbfull()->TEST_FlushMemTable();
+      ASSERT_EQ("v2", Get("1000000000000foo"));
+
+      ASSERT_OK(Put("0000000000000eee", "v3"));
+      dbfull()->TEST_FlushMemTable();
+      ASSERT_EQ("v3", Get("0000000000000eee"));
+
+      ASSERT_OK(Delete("0000000000000bar"));
+      dbfull()->TEST_FlushMemTable();
+      ASSERT_EQ("NOT_FOUND", Get("0000000000000bar"));
+
+      ASSERT_OK(Put("0000000000000eee", "v5"));
+      ASSERT_OK(Put("9000000000000eee", "v5"));
+      dbfull()->TEST_FlushMemTable();
+      ASSERT_EQ("v5", Get("0000000000000eee"));
+
+      // Test Bloom Filter
+      if (bloom_bits > 0) {
+        // Neither key nor value should exist.
+        expect_bloom_not_match = true;
+        ASSERT_EQ("NOT_FOUND", Get("5_not00000000bar"));
+
+        // Key doesn't exist any more but prefix exists.
+        if (total_order) {
+          ASSERT_EQ("NOT_FOUND", Get("1000000000000not"));
+          ASSERT_EQ("NOT_FOUND", Get("0000000000000not"));
+        }
+        expect_bloom_not_match = false;
+      }
+    }
+  }
+}
+
+TEST(PlainTableDBTest, Iterator) {
+  for (int bloom_bits = 0; bloom_bits <= 117; bloom_bits += 117) {
+    for (int total_order = 0; total_order <= 1; total_order++) {
+      bool expect_bloom_not_match = false;
+      Options options = CurrentOptions();
+      options.create_if_missing = true;
+      // Set only one bucket to force bucket conflict.
+      // Test index interval for the same prefix to be 1, 2 and 4
+      if (total_order) {
+        options.prefix_extractor = nullptr;
+        options.table_factory.reset(new TestPlainTableFactory(
+            &expect_bloom_not_match, 16, bloom_bits, 0, 2));
+      } else {
+        options.table_factory.reset(
+            new TestPlainTableFactory(&expect_bloom_not_match, 16, bloom_bits));
+      }
+      DestroyAndReopen(&options);
+
+      ASSERT_OK(Put("1000000000foo002", "v_2"));
+      ASSERT_OK(Put("0000000000000bar", "random"));
+      ASSERT_OK(Put("1000000000foo001", "v1"));
+      ASSERT_OK(Put("3000000000000bar", "bar_v"));
+      ASSERT_OK(Put("1000000000foo003", "v__3"));
+      ASSERT_OK(Put("1000000000foo004", "v__4"));
+      ASSERT_OK(Put("1000000000foo005", "v__5"));
+      ASSERT_OK(Put("1000000000foo007", "v__7"));
+      ASSERT_OK(Put("1000000000foo008", "v__8"));
+      dbfull()->TEST_FlushMemTable();
+      ASSERT_EQ("v1", Get("1000000000foo001"));
+      ASSERT_EQ("v__3", Get("1000000000foo003"));
+      Iterator* iter = dbfull()->NewIterator(ro_);
+      iter->Seek("1000000000foo000");
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo001", iter->key().ToString());
+      ASSERT_EQ("v1", iter->value().ToString());
+
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo002", iter->key().ToString());
+      ASSERT_EQ("v_2", iter->value().ToString());
+
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo003", iter->key().ToString());
+      ASSERT_EQ("v__3", iter->value().ToString());
+
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo004", iter->key().ToString());
+      ASSERT_EQ("v__4", iter->value().ToString());
+
+      iter->Seek("3000000000000bar");
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("3000000000000bar", iter->key().ToString());
+      ASSERT_EQ("bar_v", iter->value().ToString());
+
+      iter->Seek("1000000000foo000");
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo001", iter->key().ToString());
+      ASSERT_EQ("v1", iter->value().ToString());
+
+      iter->Seek("1000000000foo005");
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo005", iter->key().ToString());
+      ASSERT_EQ("v__5", iter->value().ToString());
+
+      iter->Seek("1000000000foo006");
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo007", iter->key().ToString());
+      ASSERT_EQ("v__7", iter->value().ToString());
+
+      iter->Seek("1000000000foo008");
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ("1000000000foo008", iter->key().ToString());
+      ASSERT_EQ("v__8", iter->value().ToString());
+
+      if (total_order == 0) {
+        iter->Seek("1000000000foo009");
+        ASSERT_TRUE(iter->Valid());
+        ASSERT_EQ("3000000000000bar", iter->key().ToString());
+      }
+
+      // Test Bloom Filter
+      if (bloom_bits > 0) {
+        if (!total_order) {
+          // Neither key nor value should exist.
+          expect_bloom_not_match = true;
+          iter->Seek("2not000000000bar");
+          ASSERT_TRUE(!iter->Valid());
+          ASSERT_EQ("NOT_FOUND", Get("2not000000000bar"));
+          expect_bloom_not_match = false;
+        } else {
+          expect_bloom_not_match = true;
+          ASSERT_EQ("NOT_FOUND", Get("2not000000000bar"));
+          expect_bloom_not_match = false;
+        }
+      }
+
+      delete iter;
+    }
+  }
+}
+
+// A test comparator which compare two strings in this way:
+// (1) first compare prefix of 8 bytes in alphabet order,
+// (2) if two strings share the same prefix, sort the other part of the string
+//     in the reverse alphabet order.
+class SimpleSuffixReverseComparator : public Comparator {
+ public:
+  SimpleSuffixReverseComparator() {}
+
+  virtual const char* Name() const { return "SimpleSuffixReverseComparator"; }
+
+  virtual int Compare(const Slice& a, const Slice& b) const {
+    Slice prefix_a = Slice(a.data(), 8);
+    Slice prefix_b = Slice(b.data(), 8);
+    int prefix_comp = prefix_a.compare(prefix_b);
+    if (prefix_comp != 0) {
+      return prefix_comp;
+    } else {
+      Slice suffix_a = Slice(a.data() + 8, a.size() - 8);
+      Slice suffix_b = Slice(b.data() + 8, b.size() - 8);
+      return -(suffix_a.compare(suffix_b));
+    }
+  }
+  virtual void FindShortestSeparator(std::string* start,
+                                     const Slice& limit) const {}
+
+  virtual void FindShortSuccessor(std::string* key) const {}
+};
+
+TEST(PlainTableDBTest, IteratorReverseSuffixComparator) {
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  // Set only one bucket to force bucket conflict.
+  // Test index interval for the same prefix to be 1, 2 and 4
+  SimpleSuffixReverseComparator comp;
+  options.comparator = &comp;
+  DestroyAndReopen(&options);
+
+  ASSERT_OK(Put("1000000000foo002", "v_2"));
+  ASSERT_OK(Put("0000000000000bar", "random"));
+  ASSERT_OK(Put("1000000000foo001", "v1"));
+  ASSERT_OK(Put("3000000000000bar", "bar_v"));
+  ASSERT_OK(Put("1000000000foo003", "v__3"));
+  ASSERT_OK(Put("1000000000foo004", "v__4"));
+  ASSERT_OK(Put("1000000000foo005", "v__5"));
+  ASSERT_OK(Put("1000000000foo007", "v__7"));
+  ASSERT_OK(Put("1000000000foo008", "v__8"));
+  dbfull()->TEST_FlushMemTable();
+  ASSERT_EQ("v1", Get("1000000000foo001"));
+  ASSERT_EQ("v__3", Get("1000000000foo003"));
+  Iterator* iter = dbfull()->NewIterator(ro_);
+  iter->Seek("1000000000foo009");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo008", iter->key().ToString());
+  ASSERT_EQ("v__8", iter->value().ToString());
+
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo007", iter->key().ToString());
+  ASSERT_EQ("v__7", iter->value().ToString());
+
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo005", iter->key().ToString());
+  ASSERT_EQ("v__5", iter->value().ToString());
+
+  iter->Next();
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo004", iter->key().ToString());
+  ASSERT_EQ("v__4", iter->value().ToString());
+
+  iter->Seek("3000000000000bar");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("3000000000000bar", iter->key().ToString());
+  ASSERT_EQ("bar_v", iter->value().ToString());
+
+  iter->Seek("1000000000foo005");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo005", iter->key().ToString());
+  ASSERT_EQ("v__5", iter->value().ToString());
+
+  iter->Seek("1000000000foo006");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo005", iter->key().ToString());
+  ASSERT_EQ("v__5", iter->value().ToString());
+
+  iter->Seek("1000000000foo008");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("1000000000foo008", iter->key().ToString());
+  ASSERT_EQ("v__8", iter->value().ToString());
+
+  iter->Seek("1000000000foo000");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("3000000000000bar", iter->key().ToString());
+
+  delete iter;
+}
+
+TEST(PlainTableDBTest, HashBucketConflict) {
+  for (unsigned char i = 1; i <= 3; i++) {
+    Options options = CurrentOptions();
+    options.create_if_missing = true;
+    // Set only one bucket to force bucket conflict.
+    // Test index interval for the same prefix to be 1, 2 and 4
+    options.table_factory.reset(NewTotalOrderPlainTableFactory(16, 0, 2 ^ i));
+    DestroyAndReopen(&options);
+    ASSERT_OK(Put("5000000000000fo0", "v1"));
+    ASSERT_OK(Put("5000000000000fo1", "v2"));
+    ASSERT_OK(Put("5000000000000fo2", "v"));
+    ASSERT_OK(Put("2000000000000fo0", "v3"));
+    ASSERT_OK(Put("2000000000000fo1", "v4"));
+    ASSERT_OK(Put("2000000000000fo2", "v"));
+    ASSERT_OK(Put("2000000000000fo3", "v"));
+
+    dbfull()->TEST_FlushMemTable();
+
+    ASSERT_EQ("v1", Get("5000000000000fo0"));
+    ASSERT_EQ("v2", Get("5000000000000fo1"));
+    ASSERT_EQ("v3", Get("2000000000000fo0"));
+    ASSERT_EQ("v4", Get("2000000000000fo1"));
+
+    ASSERT_EQ("NOT_FOUND", Get("5000000000000bar"));
+    ASSERT_EQ("NOT_FOUND", Get("2000000000000bar"));
+    ASSERT_EQ("NOT_FOUND", Get("5000000000000fo8"));
+    ASSERT_EQ("NOT_FOUND", Get("2000000000000fo8"));
+
+    ReadOptions ro;
+    Iterator* iter = dbfull()->NewIterator(ro);
+
+    iter->Seek("5000000000000fo0");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo0", iter->key().ToString());
+    iter->Next();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo1", iter->key().ToString());
+
+    iter->Seek("5000000000000fo1");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo1", iter->key().ToString());
+
+    iter->Seek("2000000000000fo0");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo0", iter->key().ToString());
+    iter->Next();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo1", iter->key().ToString());
+
+    iter->Seek("2000000000000fo1");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo1", iter->key().ToString());
+
+    iter->Seek("2000000000000bar");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo0", iter->key().ToString());
+
+    iter->Seek("5000000000000bar");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo0", iter->key().ToString());
+
+    iter->Seek("2000000000000fo8");
+    ASSERT_TRUE(!iter->Valid() ||
+                options.comparator->Compare(iter->key(), "20000001") > 0);
+
+    iter->Seek("5000000000000fo8");
+    ASSERT_TRUE(!iter->Valid());
+
+    iter->Seek("1000000000000fo2");
+    ASSERT_TRUE(!iter->Valid());
+
+    iter->Seek("3000000000000fo2");
+    ASSERT_TRUE(!iter->Valid());
+
+    iter->Seek("8000000000000fo2");
+    ASSERT_TRUE(!iter->Valid());
+
+    delete iter;
+  }
+}
+
+TEST(PlainTableDBTest, HashBucketConflictReverseSuffixComparator) {
+  for (unsigned char i = 1; i <= 3; i++) {
+    Options options = CurrentOptions();
+    options.create_if_missing = true;
+    SimpleSuffixReverseComparator comp;
+    options.comparator = &comp;
+    // Set only one bucket to force bucket conflict.
+    // Test index interval for the same prefix to be 1, 2 and 4
+    options.table_factory.reset(NewTotalOrderPlainTableFactory(16, 0, 2 ^ i));
+    DestroyAndReopen(&options);
+    ASSERT_OK(Put("5000000000000fo0", "v1"));
+    ASSERT_OK(Put("5000000000000fo1", "v2"));
+    ASSERT_OK(Put("5000000000000fo2", "v"));
+    ASSERT_OK(Put("2000000000000fo0", "v3"));
+    ASSERT_OK(Put("2000000000000fo1", "v4"));
+    ASSERT_OK(Put("2000000000000fo2", "v"));
+    ASSERT_OK(Put("2000000000000fo3", "v"));
+
+    dbfull()->TEST_FlushMemTable();
+
+    ASSERT_EQ("v1", Get("5000000000000fo0"));
+    ASSERT_EQ("v2", Get("5000000000000fo1"));
+    ASSERT_EQ("v3", Get("2000000000000fo0"));
+    ASSERT_EQ("v4", Get("2000000000000fo1"));
+
+    ASSERT_EQ("NOT_FOUND", Get("5000000000000bar"));
+    ASSERT_EQ("NOT_FOUND", Get("2000000000000bar"));
+    ASSERT_EQ("NOT_FOUND", Get("5000000000000fo8"));
+    ASSERT_EQ("NOT_FOUND", Get("2000000000000fo8"));
+
+    ReadOptions ro;
+    Iterator* iter = dbfull()->NewIterator(ro);
+
+    iter->Seek("5000000000000fo1");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo1", iter->key().ToString());
+    iter->Next();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo0", iter->key().ToString());
+
+    iter->Seek("5000000000000fo1");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo1", iter->key().ToString());
+
+    iter->Seek("2000000000000fo1");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo1", iter->key().ToString());
+    iter->Next();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo0", iter->key().ToString());
+
+    iter->Seek("2000000000000fo1");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo1", iter->key().ToString());
+
+    iter->Seek("2000000000000var");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("2000000000000fo3", iter->key().ToString());
+
+    iter->Seek("5000000000000var");
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ("5000000000000fo2", iter->key().ToString());
+
+    std::string seek_key = "2000000000000bar";
+    iter->Seek(seek_key);
+    ASSERT_TRUE(!iter->Valid() ||
+                options.prefix_extractor->Transform(iter->key()) !=
+                    options.prefix_extractor->Transform(seek_key));
+
+    iter->Seek("1000000000000fo2");
+    ASSERT_TRUE(!iter->Valid());
+
+    iter->Seek("3000000000000fo2");
+    ASSERT_TRUE(!iter->Valid());
+
+    iter->Seek("8000000000000fo2");
+    ASSERT_TRUE(!iter->Valid());
+
+    delete iter;
+  }
+}
+
+TEST(PlainTableDBTest, NonExistingKeyToNonEmptyBucket) {
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  // Set only one bucket to force bucket conflict.
+  // Test index interval for the same prefix to be 1, 2 and 4
+  options.table_factory.reset(NewTotalOrderPlainTableFactory(16, 0, 5));
+  DestroyAndReopen(&options);
+  ASSERT_OK(Put("5000000000000fo0", "v1"));
+  ASSERT_OK(Put("5000000000000fo1", "v2"));
+  ASSERT_OK(Put("5000000000000fo2", "v3"));
+
+  dbfull()->TEST_FlushMemTable();
+
+  ASSERT_EQ("v1", Get("5000000000000fo0"));
+  ASSERT_EQ("v2", Get("5000000000000fo1"));
+  ASSERT_EQ("v3", Get("5000000000000fo2"));
+
+  ASSERT_EQ("NOT_FOUND", Get("8000000000000bar"));
+  ASSERT_EQ("NOT_FOUND", Get("1000000000000bar"));
+
+  Iterator* iter = dbfull()->NewIterator(ro_);
+
+  iter->Seek("5000000000000bar");
+  ASSERT_TRUE(iter->Valid());
+  ASSERT_EQ("5000000000000fo0", iter->key().ToString());
+
+  iter->Seek("5000000000000fo8");
+  ASSERT_TRUE(!iter->Valid());
+
+  iter->Seek("1000000000000fo2");
+  ASSERT_TRUE(!iter->Valid());
+
+  iter->Seek("8000000000000fo2");
+  ASSERT_TRUE(!iter->Valid());
+
+  delete iter;
+}
+
+static std::string Key(int i) {
+  char buf[100];
+  snprintf(buf, sizeof(buf), "key_______%06d", i);
+  return std::string(buf);
+}
+
+static std::string RandomString(Random* rnd, int len) {
+  std::string r;
+  test::RandomString(rnd, len, &r);
+  return r;
+}
+
+TEST(PlainTableDBTest, CompactionTrigger) {
+  Options options = CurrentOptions();
+  options.write_buffer_size = 100 << 10; //100KB
+  options.num_levels = 3;
+  options.max_mem_compaction_level = 0;
+  options.level0_file_num_compaction_trigger = 3;
+  Reopen(&options);
+
+  Random rnd(301);
+
+  for (int num = 0; num < options.level0_file_num_compaction_trigger - 1;
+      num++) {
+    std::vector<std::string> values;
+    // Write 120KB (12 values, each 10K)
+    for (int i = 0; i < 12; i++) {
+      values.push_back(RandomString(&rnd, 10000));
+      ASSERT_OK(Put(Key(i), values[i]));
+    }
+    dbfull()->TEST_WaitForFlushMemTable();
+    ASSERT_EQ(NumTableFilesAtLevel(0), num + 1);
+  }
+
+  //generate one more file in level-0, and should trigger level-0 compaction
+  std::vector<std::string> values;
+  for (int i = 0; i < 12; i++) {
+    values.push_back(RandomString(&rnd, 10000));
+    ASSERT_OK(Put(Key(i), values[i]));
+  }
+  dbfull()->TEST_WaitForCompact();
+
+  ASSERT_EQ(NumTableFilesAtLevel(0), 0);
+  ASSERT_EQ(NumTableFilesAtLevel(1), 1);
+}
+
+}  // namespace rocksdb
+
+int main(int argc, char** argv) {
+  return rocksdb::test::RunAllTests();
+}
@@ -1,3 +1,8 @@
+//  Copyright (c) 2013, 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.
+
 #include <algorithm>
 #include <iostream>
 #include <vector>
@@ -6,6 +11,8 @@
 #include "rocksdb/comparator.h"
 #include "rocksdb/db.h"
 #include "rocksdb/perf_context.h"
+#include "rocksdb/slice_transform.h"
+#include "rocksdb/memtablerep.h"
 #include "util/histogram.h"
 #include "util/stop_watch.h"
 #include "util/testharness.h"
@@ -16,11 +23,15 @@ DEFINE_bool(trigger_deadlock, false,
 DEFINE_uint64(bucket_count, 100000, "number of buckets");
 DEFINE_uint64(num_locks, 10001, "number of locks");
 DEFINE_bool(random_prefix, false, "randomize prefix");
-DEFINE_uint64(total_prefixes, 1000, "total number of prefixes");
-DEFINE_uint64(items_per_prefix, 10, "total number of values per prefix");
-DEFINE_int64(write_buffer_size, 1000000000, "");
-DEFINE_int64(max_write_buffer_number, 8, "");
-DEFINE_int64(min_write_buffer_number_to_merge, 7, "");
+DEFINE_uint64(total_prefixes, 100000, "total number of prefixes");
+DEFINE_uint64(items_per_prefix, 1, "total number of values per prefix");
+DEFINE_int64(write_buffer_size, 33554432, "");
+DEFINE_int64(max_write_buffer_number, 2, "");
+DEFINE_int64(min_write_buffer_number_to_merge, 1, "");
+DEFINE_int32(skiplist_height, 4, "");
+DEFINE_int32(memtable_prefix_bloom_bits, 10000000, "");
+DEFINE_int32(memtable_prefix_bloom_probes, 10, "");
+DEFINE_int32(value_size, 40, "");

 // Path to the database on file system
 const std::string kDbName = rocksdb::test::TmpDir() + "/prefix_test";
@@ -93,6 +104,36 @@ class TestKeyComparator : public Comparator {

 };

+void PutKey(DB* db, WriteOptions write_options, uint64_t prefix,
+            uint64_t suffix, const Slice& value) {
+  TestKey test_key(prefix, suffix);
+  Slice key = TestKeyToSlice(test_key);
+  ASSERT_OK(db->Put(write_options, key, value));
+}
+
+void SeekIterator(Iterator* iter, uint64_t prefix, uint64_t suffix) {
+  TestKey test_key(prefix, suffix);
+  Slice key = TestKeyToSlice(test_key);
+  iter->Seek(key);
+}
+
+const std::string kNotFoundResult = "NOT_FOUND";
+
+std::string Get(DB* db, const ReadOptions& read_options, uint64_t prefix,
+                uint64_t suffix) {
+  TestKey test_key(prefix, suffix);
+  Slice key = TestKeyToSlice(test_key);
+
+  std::string result;
+  Status s = db->Get(read_options, key, &result);
+  if (s.IsNotFound()) {
+    result = kNotFoundResult;
+  } else if (!s.ok()) {
+    result = s.ToString();
+  }
+  return result;
+}
+
 class PrefixTest {
 public:
  std::shared_ptr<DB> OpenDb() {
@@ -104,218 +145,476 @@ class PrefixTest {
    options.min_write_buffer_number_to_merge =
      FLAGS_min_write_buffer_number_to_merge;

-    options.comparator = new TestKeyComparator();
-    if (FLAGS_use_prefix_hash_memtable) {
-      auto prefix_extractor = NewFixedPrefixTransform(8);
-      options.prefix_extractor = prefix_extractor;
-      options.memtable_factory.reset(NewHashSkipListRepFactory(
-          prefix_extractor, FLAGS_bucket_count));
-    }
+    options.memtable_prefix_bloom_bits = FLAGS_memtable_prefix_bloom_bits;
+    options.memtable_prefix_bloom_probes = FLAGS_memtable_prefix_bloom_probes;

    Status s = DB::Open(options, kDbName,  &db);
    ASSERT_OK(s);
    return std::shared_ptr<DB>(db);
  }
+
+  void FirstOption() {
+    option_config_ = kBegin;
+  }
+
+  bool NextOptions(int bucket_count) {
+    // skip some options
+    option_config_++;
+    if (option_config_ < kEnd) {
+      options.prefix_extractor.reset(NewFixedPrefixTransform(8));
+      switch(option_config_) {
+        case kHashSkipList:
+          options.memtable_factory.reset(
+              NewHashSkipListRepFactory(bucket_count, FLAGS_skiplist_height));
+          return true;
+        case kHashLinkList:
+          options.memtable_factory.reset(
+              NewHashLinkListRepFactory(bucket_count));
+          return true;
+        default:
+          return false;
+      }
+    }
+    return false;
+  }
+
+  PrefixTest() : option_config_(kBegin) {
+    options.comparator = new TestKeyComparator();
+  }
  ~PrefixTest() {
    delete options.comparator;
  }
 protected:
+  enum OptionConfig {
+    kBegin,
+    kHashSkipList,
+    kHashLinkList,
+    kEnd
+  };
+  int option_config_;
  Options options;
 };

-TEST(PrefixTest, DynamicPrefixIterator) {
+TEST(PrefixTest, TestResult) {
+  for (int num_buckets = 1; num_buckets <= 2; num_buckets++) {
+    FirstOption();
+    while (NextOptions(num_buckets)) {
+      std::cout << "*** Mem table: " << options.memtable_factory->Name()
+                << " number of buckets: " << num_buckets
+                << std::endl;
+      DestroyDB(kDbName, Options());
+      auto db = OpenDb();
+      WriteOptions write_options;
+      ReadOptions read_options;
+      read_options.prefix_seek = true;

-  DestroyDB(kDbName, Options());
-  auto db = OpenDb();
-  WriteOptions write_options;
-  ReadOptions read_options;
+      // 1. Insert one row.
+      Slice v16("v16");
+      PutKey(db.get(), write_options, 1, 6, v16);
+      std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
+      SeekIterator(iter.get(), 1, 6);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v16 == iter->value());
+      SeekIterator(iter.get(), 1, 5);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v16 == iter->value());
+      SeekIterator(iter.get(), 1, 5);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v16 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(!iter->Valid());

-  std::vector<uint64_t> prefixes;
-  for (uint64_t i = 0; i < FLAGS_total_prefixes; ++i) {
-    prefixes.push_back(i);
-  }
+      SeekIterator(iter.get(), 2, 0);
+      ASSERT_TRUE(!iter->Valid());

-  if (FLAGS_random_prefix) {
-    std::random_shuffle(prefixes.begin(), prefixes.end());
-  }
+      ASSERT_EQ(v16.ToString(), Get(db.get(), read_options, 1, 6));
+      ASSERT_EQ(kNotFoundResult, Get(db.get(), read_options, 1, 5));
+      ASSERT_EQ(kNotFoundResult, Get(db.get(), read_options, 1, 7));
+      ASSERT_EQ(kNotFoundResult, Get(db.get(), read_options, 0, 6));
+      ASSERT_EQ(kNotFoundResult, Get(db.get(), read_options, 2, 6));

-  // insert x random prefix, each with y continuous element.
-  for (auto prefix : prefixes) {
-     for (uint64_t sorted = 0; sorted < FLAGS_items_per_prefix; sorted++) {
-      TestKey test_key(prefix, sorted);
+      // 2. Insert an entry for the same prefix as the last entry in the bucket.
+      Slice v17("v17");
+      PutKey(db.get(), write_options, 1, 7, v17);
+      iter.reset(db->NewIterator(read_options));
+      SeekIterator(iter.get(), 1, 7);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());

-      Slice key = TestKeyToSlice(test_key);
-      std::string value = "v" + std::to_string(sorted);
+      SeekIterator(iter.get(), 1, 6);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v16 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(!iter->Valid());

-      ASSERT_OK(db->Put(write_options, key, value));
+      SeekIterator(iter.get(), 2, 0);
+      ASSERT_TRUE(!iter->Valid());
+
+      // 3. Insert an entry for the same prefix as the head of the bucket.
+      Slice v15("v15");
+      PutKey(db.get(), write_options, 1, 5, v15);
+      iter.reset(db->NewIterator(read_options));
+
+      SeekIterator(iter.get(), 1, 7);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+
+      SeekIterator(iter.get(), 1, 5);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v15 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v16 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+
+      SeekIterator(iter.get(), 1, 5);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v15 == iter->value());
+
+      ASSERT_EQ(v15.ToString(), Get(db.get(), read_options, 1, 5));
+      ASSERT_EQ(v16.ToString(), Get(db.get(), read_options, 1, 6));
+      ASSERT_EQ(v17.ToString(), Get(db.get(), read_options, 1, 7));
+
+      // 4. Insert an entry with a larger prefix
+      Slice v22("v22");
+      PutKey(db.get(), write_options, 2, 2, v22);
+      iter.reset(db->NewIterator(read_options));
+
+      SeekIterator(iter.get(), 2, 2);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v22 == iter->value());
+      SeekIterator(iter.get(), 2, 0);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v22 == iter->value());
+
+      SeekIterator(iter.get(), 1, 5);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v15 == iter->value());
+
+      SeekIterator(iter.get(), 1, 7);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+
+      // 5. Insert an entry with a smaller prefix
+      Slice v02("v02");
+      PutKey(db.get(), write_options, 0, 2, v02);
+      iter.reset(db->NewIterator(read_options));
+
+      SeekIterator(iter.get(), 0, 2);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v02 == iter->value());
+      SeekIterator(iter.get(), 0, 0);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v02 == iter->value());
+
+      SeekIterator(iter.get(), 2, 0);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v22 == iter->value());
+
+      SeekIterator(iter.get(), 1, 5);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v15 == iter->value());
+
+      SeekIterator(iter.get(), 1, 7);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+
+      // 6. Insert to the beginning and the end of the first prefix
+      Slice v13("v13");
+      Slice v18("v18");
+      PutKey(db.get(), write_options, 1, 3, v13);
+      PutKey(db.get(), write_options, 1, 8, v18);
+      iter.reset(db->NewIterator(read_options));
+      SeekIterator(iter.get(), 1, 7);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+
+      SeekIterator(iter.get(), 1, 3);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v13 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v15 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v16 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v17 == iter->value());
+      iter->Next();
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v18 == iter->value());
+
+      SeekIterator(iter.get(), 0, 0);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v02 == iter->value());
+
+      SeekIterator(iter.get(), 2, 0);
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_TRUE(v22 == iter->value());
+
+      ASSERT_EQ(v22.ToString(), Get(db.get(), read_options, 2, 2));
+      ASSERT_EQ(v02.ToString(), Get(db.get(), read_options, 0, 2));
+      ASSERT_EQ(v13.ToString(), Get(db.get(), read_options, 1, 3));
+      ASSERT_EQ(v15.ToString(), Get(db.get(), read_options, 1, 5));
+      ASSERT_EQ(v16.ToString(), Get(db.get(), read_options, 1, 6));
+      ASSERT_EQ(v17.ToString(), Get(db.get(), read_options, 1, 7));
+      ASSERT_EQ(v18.ToString(), Get(db.get(), read_options, 1, 8));
    }
  }
-
-  // test seek existing keys
-  HistogramImpl hist_seek_time;
-  HistogramImpl hist_seek_comparison;
-
-  if (FLAGS_use_prefix_hash_memtable) {
-    read_options.prefix_seek = true;
-  }
-  std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
-
-  for (auto prefix : prefixes) {
-    TestKey test_key(prefix, FLAGS_items_per_prefix / 2);
-    Slice key = TestKeyToSlice(test_key);
-    std::string value = "v" + std::to_string(0);
-
-    perf_context.Reset();
-    StopWatchNano timer(Env::Default(), true);
-    uint64_t total_keys = 0;
-    for (iter->Seek(key); iter->Valid(); iter->Next()) {
-      if (FLAGS_trigger_deadlock) {
-        std::cout << "Behold the deadlock!\n";
-        db->Delete(write_options, iter->key());
-      }
-      auto test_key = SliceToTestKey(iter->key());
-      if (test_key->prefix != prefix) break;
-      total_keys++;
-    }
-    hist_seek_time.Add(timer.ElapsedNanos());
-    hist_seek_comparison.Add(perf_context.user_key_comparison_count);
-    ASSERT_EQ(total_keys, FLAGS_items_per_prefix - FLAGS_items_per_prefix/2);
-  }
-
-  std::cout << "Seek key comparison: \n"
-            << hist_seek_comparison.ToString()
-            << "Seek time: \n"
-            << hist_seek_time.ToString();
-
-  // test non-existing keys
-  HistogramImpl hist_no_seek_time;
-  HistogramImpl hist_no_seek_comparison;
-
-  for (auto prefix = FLAGS_total_prefixes;
-       prefix < FLAGS_total_prefixes + 100;
-       prefix++) {
-    TestKey test_key(prefix, 0);
-    Slice key = TestKeyToSlice(test_key);
-
-    perf_context.Reset();
-    StopWatchNano timer(Env::Default(), true);
-    iter->Seek(key);
-    hist_no_seek_time.Add(timer.ElapsedNanos());
-    hist_no_seek_comparison.Add(perf_context.user_key_comparison_count);
-    ASSERT_TRUE(!iter->Valid());
-  }
-
-  std::cout << "non-existing Seek key comparison: \n"
-            << hist_no_seek_comparison.ToString()
-            << "non-existing Seek time: \n"
-            << hist_no_seek_time.ToString();
 }

-TEST(PrefixTest, PrefixHash) {
+TEST(PrefixTest, FullIterator) {
+  while (NextOptions(1000000)) {
+    DestroyDB(kDbName, Options());
+    auto db = OpenDb();
+    WriteOptions write_options;

-  DestroyDB(kDbName, Options());
-  auto db = OpenDb();
-  WriteOptions write_options;
-  ReadOptions read_options;
-
-  std::vector<uint64_t> prefixes;
-  for (uint64_t i = 0; i < FLAGS_total_prefixes; ++i) {
-    prefixes.push_back(i);
-  }
-
-  if (FLAGS_random_prefix) {
+    std::vector<uint64_t> prefixes;
+    for (uint64_t i = 0; i < 100; ++i) {
+      prefixes.push_back(i);
+    }
    std::random_shuffle(prefixes.begin(), prefixes.end());
+
+    for (auto prefix : prefixes) {
+      for (uint64_t i = 0; i < 200; ++i) {
+        TestKey test_key(prefix, i);
+        Slice key = TestKeyToSlice(test_key);
+        ASSERT_OK(db->Put(write_options, key, Slice("0")));
+      }
+    }
+
+    auto func = [](void* db_void) {
+      auto db = reinterpret_cast<DB*>(db_void);
+      std::unique_ptr<Iterator> iter(db->NewIterator(ReadOptions()));
+      iter->SeekToFirst();
+      for (int i = 0; i < 3; ++i) {
+        iter->Next();
+      }
+    };
+
+    auto env = Env::Default();
+    for (int i = 0; i < 16; ++i) {
+      env->StartThread(func, reinterpret_cast<void*>(db.get()));
+    }
+    env->WaitForJoin();
  }
+}

-  // insert x random prefix, each with y continuous element.
-  HistogramImpl hist_put_time;
-  HistogramImpl hist_put_comparison;
+TEST(PrefixTest, DynamicPrefixIterator) {
+  while (NextOptions(FLAGS_bucket_count)) {
+    std::cout << "*** Mem table: " << options.memtable_factory->Name()
+        << std::endl;
+    DestroyDB(kDbName, Options());
+    auto db = OpenDb();
+    WriteOptions write_options;
+    ReadOptions read_options;

-  for (auto prefix : prefixes) {
-     for (uint64_t sorted = 0; sorted < FLAGS_items_per_prefix; sorted++) {
-      TestKey test_key(prefix, sorted);
+    std::vector<uint64_t> prefixes;
+    for (uint64_t i = 0; i < FLAGS_total_prefixes; ++i) {
+      prefixes.push_back(i);
+    }

+    if (FLAGS_random_prefix) {
+      std::random_shuffle(prefixes.begin(), prefixes.end());
+    }
+
+    HistogramImpl hist_put_time;
+    HistogramImpl hist_put_comparison;
+
+    // insert x random prefix, each with y continuous element.
+    for (auto prefix : prefixes) {
+       for (uint64_t sorted = 0; sorted < FLAGS_items_per_prefix; sorted++) {
+        TestKey test_key(prefix, sorted);
+
+        Slice key = TestKeyToSlice(test_key);
+        std::string value(FLAGS_value_size, 0);
+
+        perf_context.Reset();
+        StopWatchNano timer(Env::Default(), true);
+        ASSERT_OK(db->Put(write_options, key, value));
+        hist_put_time.Add(timer.ElapsedNanos());
+        hist_put_comparison.Add(perf_context.user_key_comparison_count);
+      }
+    }
+
+    std::cout << "Put key comparison: \n" << hist_put_comparison.ToString()
+              << "Put time: \n" << hist_put_time.ToString();
+
+    // test seek existing keys
+    HistogramImpl hist_seek_time;
+    HistogramImpl hist_seek_comparison;
+
+    if (FLAGS_use_prefix_hash_memtable) {
+      read_options.prefix_seek = true;
+    }
+    std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
+
+    for (auto prefix : prefixes) {
+      TestKey test_key(prefix, FLAGS_items_per_prefix / 2);
      Slice key = TestKeyToSlice(test_key);
-      std::string value = "v" + std::to_string(sorted);
+      std::string value = "v" + std::to_string(0);

      perf_context.Reset();
      StopWatchNano timer(Env::Default(), true);
-      ASSERT_OK(db->Put(write_options, key, value));
-      hist_put_time.Add(timer.ElapsedNanos());
-      hist_put_comparison.Add(perf_context.user_key_comparison_count);
-    }
-  }
-
-  std::cout << "Put key comparison: \n" << hist_put_comparison.ToString()
-            << "Put time: \n" << hist_put_time.ToString();
-
-
-  // test seek existing keys
-  HistogramImpl hist_seek_time;
-  HistogramImpl hist_seek_comparison;
-
-  for (auto prefix : prefixes) {
-    TestKey test_key(prefix, 0);
-    Slice key = TestKeyToSlice(test_key);
-    std::string value = "v" + std::to_string(0);
-
-    Slice key_prefix;
-    if (FLAGS_use_prefix_hash_memtable) {
-      key_prefix = options.prefix_extractor->Transform(key);
-      read_options.prefix = &key_prefix;
-    }
-    std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
-
-    perf_context.Reset();
-    StopWatchNano timer(Env::Default(), true);
-    uint64_t total_keys = 0;
-    for (iter->Seek(key); iter->Valid(); iter->Next()) {
-      if (FLAGS_trigger_deadlock) {
-        std::cout << "Behold the deadlock!\n";
-        db->Delete(write_options, iter->key());
+      uint64_t total_keys = 0;
+      for (iter->Seek(key); iter->Valid(); iter->Next()) {
+        if (FLAGS_trigger_deadlock) {
+          std::cout << "Behold the deadlock!\n";
+          db->Delete(write_options, iter->key());
+        }
+        auto test_key = SliceToTestKey(iter->key());
+        if (test_key->prefix != prefix) break;
+        total_keys++;
      }
-      auto test_key = SliceToTestKey(iter->key());
-      if (test_key->prefix != prefix) break;
-      total_keys++;
+      hist_seek_time.Add(timer.ElapsedNanos());
+      hist_seek_comparison.Add(perf_context.user_key_comparison_count);
+      ASSERT_EQ(total_keys, FLAGS_items_per_prefix - FLAGS_items_per_prefix/2);
    }
-    hist_seek_time.Add(timer.ElapsedNanos());
-    hist_seek_comparison.Add(perf_context.user_key_comparison_count);
-    ASSERT_EQ(total_keys, FLAGS_items_per_prefix);
-  }

-  std::cout << "Seek key comparison: \n"
-            << hist_seek_comparison.ToString()
-            << "Seek time: \n"
-            << hist_seek_time.ToString();
+    std::cout << "Seek key comparison: \n"
+              << hist_seek_comparison.ToString()
+              << "Seek time: \n"
+              << hist_seek_time.ToString();

-  // test non-existing keys
-  HistogramImpl hist_no_seek_time;
-  HistogramImpl hist_no_seek_comparison;
+    // test non-existing keys
+    HistogramImpl hist_no_seek_time;
+    HistogramImpl hist_no_seek_comparison;

-  for (auto prefix = FLAGS_total_prefixes;
-       prefix < FLAGS_total_prefixes + 100;
-       prefix++) {
-    TestKey test_key(prefix, 0);
-    Slice key = TestKeyToSlice(test_key);
+    for (auto prefix = FLAGS_total_prefixes;
+         prefix < FLAGS_total_prefixes + 10000;
+         prefix++) {
+      TestKey test_key(prefix, 0);
+      Slice key = TestKeyToSlice(test_key);

-    if (FLAGS_use_prefix_hash_memtable) {
-      Slice key_prefix = options.prefix_extractor->Transform(key);
-      read_options.prefix = &key_prefix;
+      perf_context.Reset();
+      StopWatchNano timer(Env::Default(), true);
+      iter->Seek(key);
+      hist_no_seek_time.Add(timer.ElapsedNanos());
+      hist_no_seek_comparison.Add(perf_context.user_key_comparison_count);
+      ASSERT_TRUE(!iter->Valid());
    }
-    std::unique_ptr<Iterator> iter(db->NewIterator(read_options));

-    perf_context.Reset();
-    StopWatchNano timer(Env::Default(), true);
-    iter->Seek(key);
-    hist_no_seek_time.Add(timer.ElapsedNanos());
-    hist_no_seek_comparison.Add(perf_context.user_key_comparison_count);
-    ASSERT_TRUE(!iter->Valid());
+    std::cout << "non-existing Seek key comparison: \n"
+              << hist_no_seek_comparison.ToString()
+              << "non-existing Seek time: \n"
+              << hist_no_seek_time.ToString();
  }
+}

-  std::cout << "non-existing Seek key comparison: \n"
-            << hist_no_seek_comparison.ToString()
-            << "non-existing Seek time: \n"
-            << hist_no_seek_time.ToString();
+TEST(PrefixTest, PrefixHash) {
+  while (NextOptions(FLAGS_bucket_count)) {
+    std::cout << "*** Mem table: " << options.memtable_factory->Name()
+        << std::endl;
+    DestroyDB(kDbName, Options());
+    auto db = OpenDb();
+    WriteOptions write_options;
+    ReadOptions read_options;
+
+    std::vector<uint64_t> prefixes;
+    for (uint64_t i = 0; i < FLAGS_total_prefixes; ++i) {
+      prefixes.push_back(i);
+    }
+
+    if (FLAGS_random_prefix) {
+      std::random_shuffle(prefixes.begin(), prefixes.end());
+    }
+
+    // insert x random prefix, each with y continuous element.
+    HistogramImpl hist_put_time;
+    HistogramImpl hist_put_comparison;
+
+    for (auto prefix : prefixes) {
+       for (uint64_t sorted = 0; sorted < FLAGS_items_per_prefix; sorted++) {
+        TestKey test_key(prefix, sorted);
+
+        Slice key = TestKeyToSlice(test_key);
+        std::string value = "v" + std::to_string(sorted);
+
+        perf_context.Reset();
+        StopWatchNano timer(Env::Default(), true);
+        ASSERT_OK(db->Put(write_options, key, value));
+        hist_put_time.Add(timer.ElapsedNanos());
+        hist_put_comparison.Add(perf_context.user_key_comparison_count);
+      }
+    }
+
+    std::cout << "Put key comparison: \n" << hist_put_comparison.ToString()
+              << "Put time: \n" << hist_put_time.ToString();
+
+
+    // test seek existing keys
+    HistogramImpl hist_seek_time;
+    HistogramImpl hist_seek_comparison;
+
+    for (auto prefix : prefixes) {
+      TestKey test_key(prefix, 0);
+      Slice key = TestKeyToSlice(test_key);
+      std::string value = "v" + std::to_string(0);
+
+      Slice key_prefix;
+      if (FLAGS_use_prefix_hash_memtable) {
+        key_prefix = options.prefix_extractor->Transform(key);
+        read_options.prefix = &key_prefix;
+      }
+      std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
+
+      perf_context.Reset();
+      StopWatchNano timer(Env::Default(), true);
+      uint64_t total_keys = 0;
+      for (iter->Seek(key); iter->Valid(); iter->Next()) {
+        if (FLAGS_trigger_deadlock) {
+          std::cout << "Behold the deadlock!\n";
+          db->Delete(write_options, iter->key());
+        }
+        auto test_key = SliceToTestKey(iter->key());
+        if (test_key->prefix != prefix) break;
+        total_keys++;
+      }
+      hist_seek_time.Add(timer.ElapsedNanos());
+      hist_seek_comparison.Add(perf_context.user_key_comparison_count);
+      ASSERT_EQ(total_keys, FLAGS_items_per_prefix);
+    }
+
+    std::cout << "Seek key comparison: \n"
+              << hist_seek_comparison.ToString()
+              << "Seek time: \n"
+              << hist_seek_time.ToString();
+
+    // test non-existing keys
+    HistogramImpl hist_no_seek_time;
+    HistogramImpl hist_no_seek_comparison;
+
+    for (auto prefix = FLAGS_total_prefixes;
+         prefix < FLAGS_total_prefixes + 100;
+         prefix++) {
+      TestKey test_key(prefix, 0);
+      Slice key = TestKeyToSlice(test_key);
+
+      if (FLAGS_use_prefix_hash_memtable) {
+        Slice key_prefix = options.prefix_extractor->Transform(key);
+        read_options.prefix = &key_prefix;
+      }
+      std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
+
+      perf_context.Reset();
+      StopWatchNano timer(Env::Default(), true);
+      iter->Seek(key);
+      hist_no_seek_time.Add(timer.ElapsedNanos());
+      hist_no_seek_comparison.Add(perf_context.user_key_comparison_count);
+      ASSERT_TRUE(!iter->Valid());
+    }
+
+    std::cout << "non-existing Seek key comparison: \n"
+              << hist_no_seek_comparison.ToString()
+              << "non-existing Seek time: \n"
+              << hist_no_seek_time.ToString();
+  }
 }

 }
@@ -119,7 +119,7 @@ class Repairer {
      return status;
    }
    if (filenames.empty()) {
-      return Status::IOError(dbname_, "repair found no files");
+      return Status::Corruption(dbname_, "repair found no files");
    }

    uint64_t number;
@@ -222,10 +222,8 @@ class Repairer {
    FileMetaData meta;
    meta.number = next_file_number_++;
    Iterator* iter = mem->NewIterator();
-    status = BuildTable(dbname_, env_, options_, storage_options_,
-                        table_cache_, iter, &meta,
-                        icmp_.user_comparator(), 0, 0,
-                        kNoCompression);
+    status = BuildTable(dbname_, env_, options_, storage_options_, table_cache_,
+                        iter, &meta, icmp_, 0, 0, kNoCompression);
    delete iter;
    delete mem->Unref();
    mem = nullptr;
@@ -243,7 +241,6 @@ class Repairer {
  }

  void ExtractMetaData() {
-    std::vector<TableInfo> kept;
    for (size_t i = 0; i < table_numbers_.size(); i++) {
      TableInfo t;
      t.meta.number = table_numbers_[i];
@@ -265,8 +262,9 @@ class Repairer {
    int counter = 0;
    Status status = env_->GetFileSize(fname, &t->meta.file_size);
    if (status.ok()) {
+      FileMetaData dummy_meta(t->meta.number, t->meta.file_size);
      Iterator* iter = table_cache_->NewIterator(
-          ReadOptions(), storage_options_, t->meta.number, t->meta.file_size);
+          ReadOptions(), storage_options_, icmp_, dummy_meta);
      bool empty = true;
      ParsedInternalKey parsed;
      t->min_sequence = 0;
@@ -308,7 +306,8 @@ class Repairer {
  Status WriteDescriptor() {
    std::string tmp = TempFileName(dbname_, 1);
    unique_ptr<WritableFile> file;
-    Status status = env_->NewWritableFile(tmp, &file, storage_options_);
+    Status status = env_->NewWritableFile(
+        tmp, &file, env_->OptimizeForManifestWrite(storage_options_));
    if (!status.ok()) {
      return status;
    }
@@ -22,6 +22,8 @@
 #include "rocksdb/compaction_filter.h"
 #include "rocksdb/env.h"
 #include "rocksdb/table.h"
+#include "rocksdb/table_properties.h"
+#include "table/table_builder.h"
 #include "util/hash.h"
 #include "util/logging.h"
 #include "util/mutexlock.h"
@@ -31,6 +33,7 @@

 using std::unique_ptr;

+// IS THIS FILE STILL NEEDED?
 namespace rocksdb {

 // SimpleTable is a simple table format for UNIT TEST ONLY. It is not built
@@ -84,18 +87,16 @@ public:

  Iterator* NewIterator(const ReadOptions&) override;

-  Status Get(
-      const ReadOptions&, const Slice& key, void* arg,
-      bool (*handle_result)(void* arg, const Slice& k, const Slice& v, bool),
-      void (*mark_key_may_exist)(void*) = nullptr) override;
+  Status Get(const ReadOptions&, const Slice& key, void* arg,
+             bool (*handle_result)(void* arg, const ParsedInternalKey& k,
+                                   const Slice& v, bool),
+             void (*mark_key_may_exist)(void*) = nullptr) override;

  uint64_t ApproximateOffsetOf(const Slice& key) override;

-  bool TEST_KeyInCache(const ReadOptions& options, const Slice& key) override;
-
  void SetupForCompaction() override;

-  TableProperties& GetTableProperties() override;
+  std::shared_ptr<const TableProperties> GetTableProperties() const override;

  ~SimpleTableReader();

@@ -171,7 +172,7 @@ struct SimpleTableReader::Rep {
  unique_ptr<RandomAccessFile> file;
  uint64_t index_start_offset;
  int num_entries;
-  TableProperties table_properties;
+  std::shared_ptr<TableProperties> table_properties;

  const static int user_key_size = 16;
  const static int offset_length = 8;
@@ -214,7 +215,8 @@ Status SimpleTableReader::Open(const Options& options,
 void SimpleTableReader::SetupForCompaction() {
 }

-TableProperties& SimpleTableReader::GetTableProperties() {
+std::shared_ptr<const TableProperties> SimpleTableReader::GetTableProperties()
+    const {
  return rep_->table_properties;
 }

@@ -244,7 +246,8 @@ Status SimpleTableReader::GetOffset(const Slice& target, uint64_t* offset) {
      return s;
    }

-    int compare_result = rep_->options.comparator->Compare(tmp_slice, target);
+    InternalKeyComparator ikc(rep_->options.comparator);
+    int compare_result = ikc.Compare(tmp_slice, target);

    if (compare_result < 0) {
      if (left == right) {
@@ -279,14 +282,20 @@ Status SimpleTableReader::GetOffset(const Slice& target, uint64_t* offset) {
  return s;
 }

-Status SimpleTableReader::Get(
-    const ReadOptions& options, const Slice& k, void* arg,
-    bool (*saver)(void*, const Slice&, const Slice&, bool),
-    void (*mark_key_may_exist)(void*)) {
+Status SimpleTableReader::Get(const ReadOptions& options, const Slice& k,
+                              void* arg,
+                              bool (*saver)(void*, const ParsedInternalKey&,
+                                            const Slice&, bool),
+                              void (*mark_key_may_exist)(void*)) {
  Status s;
  SimpleTableIterator* iter = new SimpleTableIterator(this);
  for (iter->Seek(k); iter->Valid(); iter->Next()) {
-    if (!(*saver)(arg, iter->key(), iter->value(), true)) {
+    ParsedInternalKey parsed_key;
+    if (!ParseInternalKey(iter->key(), &parsed_key)) {
+      return Status::Corruption(Slice());
+    }
+
+    if (!(*saver)(arg, parsed_key, iter->value(), true)) {
      break;
    }
  }
@@ -295,11 +304,6 @@ Status SimpleTableReader::Get(
  return s;
 }

-bool SimpleTableReader::TEST_KeyInCache(const ReadOptions& options,
-                                        const Slice& key) {
-  return false;
-}
-
 uint64_t SimpleTableReader::ApproximateOffsetOf(const Slice& key) {
  return 0;
 }
@@ -540,27 +544,30 @@ public:
  const char* Name() const override {
    return "SimpleTable";
  }
-  Status GetTableReader(const Options& options, const EnvOptions& soptions,
-                        unique_ptr<RandomAccessFile> && file,
-                        uint64_t file_size,
+  Status NewTableReader(const Options& options, const EnvOptions& soptions,
+                        const InternalKeyComparator& internal_key,
+                        unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
                        unique_ptr<TableReader>* table_reader) const;

-  TableBuilder* GetTableBuilder(const Options& options, WritableFile* file,
+  TableBuilder* NewTableBuilder(const Options& options,
+                                const InternalKeyComparator& internal_key,
+                                WritableFile* file,
                                CompressionType compression_type) const;
 };

-Status SimpleTableFactory::GetTableReader(
+Status SimpleTableFactory::NewTableReader(
    const Options& options, const EnvOptions& soptions,
-    unique_ptr<RandomAccessFile> && file, uint64_t file_size,
+    const InternalKeyComparator& internal_key,
+    unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
    unique_ptr<TableReader>* table_reader) const {

  return SimpleTableReader::Open(options, soptions, std::move(file), file_size,
                                 table_reader);
 }

-TableBuilder* SimpleTableFactory::GetTableBuilder(
-    const Options& options, WritableFile* file,
-    CompressionType compression_type) const {
+TableBuilder* SimpleTableFactory::NewTableBuilder(
+    const Options& options, const InternalKeyComparator& internal_key,
+    WritableFile* file, CompressionType compression_type) const {
  return new SimpleTableBuilder(options, file, compression_type);
 }

@@ -33,9 +33,10 @@
 #pragma once
 #include <assert.h>
 #include <stdlib.h>
+#include "util/arena.h"
 #include "port/port.h"
+#include "util/arena.h"
 #include "util/random.h"
-#include "rocksdb/arena.h"

 namespace rocksdb {

@@ -48,7 +49,8 @@ class SkipList {
  // Create a new SkipList object that will use "cmp" for comparing keys,
  // and will allocate memory using "*arena".  Objects allocated in the arena
  // must remain allocated for the lifetime of the skiplist object.
-  explicit SkipList(Comparator cmp, Arena* arena);
+  explicit SkipList(Comparator cmp, Arena* arena,
+                    int32_t max_height = 12, int32_t branching_factor = 4);

  // Insert key into the list.
  // REQUIRES: nothing that compares equal to key is currently in the list.
@@ -102,7 +104,8 @@ class SkipList {
  };

 private:
-  enum { kMaxHeight = 12 };
+  const int32_t kMaxHeight_;
+  const int32_t kBranching_;

  // Immutable after construction
  Comparator const compare_;
@@ -115,8 +118,8 @@ class SkipList {
  port::AtomicPointer max_height_;   // Height of the entire list

  // Used for optimizing sequential insert patterns
-  Node* prev_[kMaxHeight];
-  int   prev_height_;
+  Node** prev_;
+  int32_t prev_height_;

  inline int GetMaxHeight() const {
    return static_cast<int>(
@@ -155,7 +158,7 @@ class SkipList {

 // Implementation details follow
 template<typename Key, class Comparator>
-struct SkipList<Key,Comparator>::Node {
+struct SkipList<Key, Comparator>::Node {
  explicit Node(const Key& k) : key(k) { }

  Key const key;
@@ -191,43 +194,43 @@ struct SkipList<Key,Comparator>::Node {
 };

 template<typename Key, class Comparator>
-typename SkipList<Key,Comparator>::Node*
-SkipList<Key,Comparator>::NewNode(const Key& key, int height) {
+typename SkipList<Key, Comparator>::Node*
+SkipList<Key, Comparator>::NewNode(const Key& key, int height) {
  char* mem = arena_->AllocateAligned(
      sizeof(Node) + sizeof(port::AtomicPointer) * (height - 1));
  return new (mem) Node(key);
 }

 template<typename Key, class Comparator>
-inline SkipList<Key,Comparator>::Iterator::Iterator(const SkipList* list) {
+inline SkipList<Key, Comparator>::Iterator::Iterator(const SkipList* list) {
  SetList(list);
 }

 template<typename Key, class Comparator>
-inline void SkipList<Key,Comparator>::Iterator::SetList(const SkipList* list) {
+inline void SkipList<Key, Comparator>::Iterator::SetList(const SkipList* list) {
  list_ = list;
  node_ = nullptr;
 }

 template<typename Key, class Comparator>
-inline bool SkipList<Key,Comparator>::Iterator::Valid() const {
+inline bool SkipList<Key, Comparator>::Iterator::Valid() const {
  return node_ != nullptr;
 }

 template<typename Key, class Comparator>
-inline const Key& SkipList<Key,Comparator>::Iterator::key() const {
+inline const Key& SkipList<Key, Comparator>::Iterator::key() const {
  assert(Valid());
  return node_->key;
 }

 template<typename Key, class Comparator>
-inline void SkipList<Key,Comparator>::Iterator::Next() {
+inline void SkipList<Key, Comparator>::Iterator::Next() {
  assert(Valid());
  node_ = node_->Next(0);
 }

 template<typename Key, class Comparator>
-inline void SkipList<Key,Comparator>::Iterator::Prev() {
+inline void SkipList<Key, Comparator>::Iterator::Prev() {
  // Instead of using explicit "prev" links, we just search for the
  // last node that falls before key.
  assert(Valid());
@@ -238,17 +241,17 @@ inline void SkipList<Key,Comparator>::Iterator::Prev() {
 }

 template<typename Key, class Comparator>
-inline void SkipList<Key,Comparator>::Iterator::Seek(const Key& target) {
+inline void SkipList<Key, Comparator>::Iterator::Seek(const Key& target) {
  node_ = list_->FindGreaterOrEqual(target, nullptr);
 }

 template<typename Key, class Comparator>
-inline void SkipList<Key,Comparator>::Iterator::SeekToFirst() {
+inline void SkipList<Key, Comparator>::Iterator::SeekToFirst() {
  node_ = list_->head_->Next(0);
 }

 template<typename Key, class Comparator>
-inline void SkipList<Key,Comparator>::Iterator::SeekToLast() {
+inline void SkipList<Key, Comparator>::Iterator::SeekToLast() {
  node_ = list_->FindLast();
  if (node_ == list_->head_) {
    node_ = nullptr;
@@ -256,27 +259,26 @@ inline void SkipList<Key,Comparator>::Iterator::SeekToLast() {
 }

 template<typename Key, class Comparator>
-int SkipList<Key,Comparator>::RandomHeight() {
+int SkipList<Key, Comparator>::RandomHeight() {
  // Increase height with probability 1 in kBranching
-  static const unsigned int kBranching = 4;
  int height = 1;
-  while (height < kMaxHeight && ((rnd_.Next() % kBranching) == 0)) {
+  while (height < kMaxHeight_ && ((rnd_.Next() % kBranching_) == 0)) {
    height++;
  }
  assert(height > 0);
-  assert(height <= kMaxHeight);
+  assert(height <= kMaxHeight_);
  return height;
 }

 template<typename Key, class Comparator>
-bool SkipList<Key,Comparator>::KeyIsAfterNode(const Key& key, Node* n) const {
+bool SkipList<Key, Comparator>::KeyIsAfterNode(const Key& key, Node* n) const {
  // nullptr n is considered infinite
  return (n != nullptr) && (compare_(n->key, key) < 0);
 }

 template<typename Key, class Comparator>
-typename SkipList<Key,Comparator>::Node* SkipList<Key,Comparator>::FindGreaterOrEqual(const Key& key, Node** prev)
-    const {
+typename SkipList<Key, Comparator>::Node* SkipList<Key, Comparator>::
+  FindGreaterOrEqual(const Key& key, Node** prev) const {
  // Use prev as an optimization hint and fallback to slow path
  if (prev && !KeyIsAfterNode(key, prev[0]->Next(0))) {
    Node* x = prev[0];
@@ -313,8 +315,8 @@ typename SkipList<Key,Comparator>::Node* SkipList<Key,Comparator>::FindGreaterOr
 }

 template<typename Key, class Comparator>
-typename SkipList<Key,Comparator>::Node*
-SkipList<Key,Comparator>::FindLessThan(const Key& key) const {
+typename SkipList<Key, Comparator>::Node*
+SkipList<Key, Comparator>::FindLessThan(const Key& key) const {
  Node* x = head_;
  int level = GetMaxHeight() - 1;
  while (true) {
@@ -334,7 +336,7 @@ SkipList<Key,Comparator>::FindLessThan(const Key& key) const {
 }

 template<typename Key, class Comparator>
-typename SkipList<Key,Comparator>::Node* SkipList<Key,Comparator>::FindLast()
+typename SkipList<Key, Comparator>::Node* SkipList<Key, Comparator>::FindLast()
    const {
  Node* x = head_;
  int level = GetMaxHeight() - 1;
@@ -354,21 +356,31 @@ typename SkipList<Key,Comparator>::Node* SkipList<Key,Comparator>::FindLast()
 }

 template<typename Key, class Comparator>
-SkipList<Key,Comparator>::SkipList(Comparator cmp, Arena* arena)
-    : compare_(cmp),
+SkipList<Key, Comparator>::SkipList(const Comparator cmp, Arena* arena,
+                                   int32_t max_height,
+                                   int32_t branching_factor)
+    : kMaxHeight_(max_height),
+      kBranching_(branching_factor),
+      compare_(cmp),
      arena_(arena),
-      head_(NewNode(0 /* any key will do */, kMaxHeight)),
+      head_(NewNode(0 /* any key will do */, max_height)),
      max_height_(reinterpret_cast<void*>(1)),
      prev_height_(1),
      rnd_(0xdeadbeef) {
-  for (int i = 0; i < kMaxHeight; i++) {
+  assert(kMaxHeight_ > 0);
+  assert(kBranching_ > 0);
+  // Allocate the prev_ Node* array, directly from the passed-in arena.
+  // prev_ does not need to be freed, as its life cycle is tied up with
+  // the arena as a whole.
+  prev_ = (Node**) arena_->AllocateAligned(sizeof(Node*) * kMaxHeight_);
+  for (int i = 0; i < kMaxHeight_; i++) {
    head_->SetNext(i, nullptr);
    prev_[i] = head_;
  }
 }

 template<typename Key, class Comparator>
-void SkipList<Key,Comparator>::Insert(const Key& key) {
+void SkipList<Key, Comparator>::Insert(const Key& key) {
  // TODO(opt): We can use a barrier-free variant of FindGreaterOrEqual()
  // here since Insert() is externally synchronized.
  Node* x = FindGreaterOrEqual(key, prev_);
@@ -405,7 +417,7 @@ void SkipList<Key,Comparator>::Insert(const Key& key) {
 }

 template<typename Key, class Comparator>
-bool SkipList<Key,Comparator>::Contains(const Key& key) const {
+bool SkipList<Key, Comparator>::Contains(const Key& key) const {
  Node* x = FindGreaterOrEqual(key, nullptr);
  if (x != nullptr && Equal(key, x->key)) {
    return true;
@@ -10,7 +10,7 @@
 #include "db/skiplist.h"
 #include <set>
 #include "rocksdb/env.h"
-#include "util/arena_impl.h"
+#include "util/arena.h"
 #include "util/hash.h"
 #include "util/random.h"
 #include "util/testharness.h"
@@ -34,9 +34,9 @@ struct TestComparator {
 class SkipTest { };

 TEST(SkipTest, Empty) {
-  ArenaImpl arena_impl;
+  Arena arena;
  TestComparator cmp;
-  SkipList<Key, TestComparator> list(cmp, &arena_impl);
+  SkipList<Key, TestComparator> list(cmp, &arena);
  ASSERT_TRUE(!list.Contains(10));

  SkipList<Key, TestComparator>::Iterator iter(&list);
@@ -54,9 +54,9 @@ TEST(SkipTest, InsertAndLookup) {
  const int R = 5000;
  Random rnd(1000);
  std::set<Key> keys;
-  ArenaImpl arena_impl;
+  Arena arena;
  TestComparator cmp;
-  SkipList<Key, TestComparator> list(cmp, &arena_impl);
+  SkipList<Key, TestComparator> list(cmp, &arena);
  for (int i = 0; i < N; i++) {
    Key key = rnd.Next() % R;
    if (keys.insert(key).second) {
@@ -209,14 +209,14 @@ class ConcurrentTest {
  // Current state of the test
  State current_;

-  ArenaImpl arena_impl_;
+  Arena arena_;

  // SkipList is not protected by mu_.  We just use a single writer
  // thread to modify it.
  SkipList<Key, TestComparator> list_;

 public:
-  ConcurrentTest() : list_(TestComparator(), &arena_impl_) { }
+  ConcurrentTest() : list_(TestComparator(), &arena_) {}

  // REQUIRES: External synchronization
  void WriteStep(Random* rnd) {
@@ -10,9 +10,10 @@
 #include "db/table_cache.h"

 #include "db/filename.h"
+#include "db/version_edit.h"

 #include "rocksdb/statistics.h"
-#include "rocksdb/table.h"
+#include "table/table_reader.h"
 #include "util/coding.h"
 #include "util/stop_watch.h"

@@ -50,7 +51,16 @@ TableCache::TableCache(const std::string& dbname,
 TableCache::~TableCache() {
 }

+TableReader* TableCache::GetTableReaderFromHandle(Cache::Handle* handle) {
+  return reinterpret_cast<TableReader*>(cache_->Value(handle));
+}
+
+void TableCache::ReleaseHandle(Cache::Handle* handle) {
+  cache_->Release(handle);
+}
+
 Status TableCache::FindTable(const EnvOptions& toptions,
+                             const InternalKeyComparator& internal_comparator,
                             uint64_t file_number, uint64_t file_size,
                             Cache::Handle** handle, bool* table_io,
                             const bool no_io) {
@@ -74,9 +84,9 @@ Status TableCache::FindTable(const EnvOptions& toptions,
        file->Hint(RandomAccessFile::RANDOM);
      }
      StopWatch sw(env_, options_->statistics.get(), TABLE_OPEN_IO_MICROS);
-      s = options_->table_factory->GetTableReader(*options_, toptions,
-                                                  std::move(file), file_size,
-                                                  &table_reader);
+      s = options_->table_factory->NewTableReader(
+          *options_, toptions, internal_comparator, std::move(file), file_size,
+          &table_reader);
    }

    if (!s.ok()) {
@@ -94,25 +104,28 @@ Status TableCache::FindTable(const EnvOptions& toptions,

 Iterator* TableCache::NewIterator(const ReadOptions& options,
                                  const EnvOptions& toptions,
-                                  uint64_t file_number,
-                                  uint64_t file_size,
+                                  const InternalKeyComparator& icomparator,
+                                  const FileMetaData& file_meta,
                                  TableReader** table_reader_ptr,
                                  bool for_compaction) {
  if (table_reader_ptr != nullptr) {
    *table_reader_ptr = nullptr;
  }
-
-  Cache::Handle* handle = nullptr;
-  Status s = FindTable(toptions, file_number, file_size, &handle,
-                       nullptr, options.read_tier == kBlockCacheTier);
+  Cache::Handle* handle = file_meta.table_reader_handle;
+  Status s;
+  if (!handle) {
+    s = FindTable(toptions, icomparator, file_meta.number, file_meta.file_size,
+                  &handle, nullptr, options.read_tier == kBlockCacheTier);
+  }
  if (!s.ok()) {
    return NewErrorIterator(s);
  }

-  TableReader* table_reader =
-    reinterpret_cast<TableReader*>(cache_->Value(handle));
+  TableReader* table_reader = GetTableReaderFromHandle(handle);
  Iterator* result = table_reader->NewIterator(options);
-  result->RegisterCleanup(&UnrefEntry, cache_.get(), handle);
+  if (!file_meta.table_reader_handle) {
+    result->RegisterCleanup(&UnrefEntry, cache_.get(), handle);
+  }
  if (table_reader_ptr != nullptr) {
    *table_reader_ptr = table_reader;
  }
@@ -125,22 +138,24 @@ Iterator* TableCache::NewIterator(const ReadOptions& options,
 }

 Status TableCache::Get(const ReadOptions& options,
-                       uint64_t file_number,
-                       uint64_t file_size,
-                       const Slice& k,
-                       void* arg,
-                       bool (*saver)(void*, const Slice&, const Slice&, bool),
-                       bool* table_io,
-                       void (*mark_key_may_exist)(void*)) {
-  Cache::Handle* handle = nullptr;
-  Status s = FindTable(storage_options_, file_number, file_size,
-                       &handle, table_io,
-                       options.read_tier == kBlockCacheTier);
+                       const InternalKeyComparator& internal_comparator,
+                       const FileMetaData& file_meta, const Slice& k, void* arg,
+                       bool (*saver)(void*, const ParsedInternalKey&,
+                                     const Slice&, bool),
+                       bool* table_io, void (*mark_key_may_exist)(void*)) {
+  Cache::Handle* handle = file_meta.table_reader_handle;
+  Status s;
+  if (!handle) {
+    s = FindTable(storage_options_, internal_comparator, file_meta.number,
+                  file_meta.file_size, &handle, table_io,
+                  options.read_tier == kBlockCacheTier);
+  }
  if (s.ok()) {
-    TableReader* t =
-      reinterpret_cast<TableReader*>(cache_->Value(handle));
+    TableReader* t = GetTableReaderFromHandle(handle);
    s = t->Get(options, k, arg, saver, mark_key_may_exist);
-    cache_->Release(handle);
+    if (!file_meta.table_reader_handle) {
+      ReleaseHandle(handle);
+    }
  } else if (options.read_tier && s.IsIncomplete()) {
    // Couldnt find Table in cache but treat as kFound if no_io set
    (*mark_key_may_exist)(arg);
@@ -148,22 +163,56 @@ Status TableCache::Get(const ReadOptions& options,
  }
  return s;
 }
+Status TableCache::GetTableProperties(
+    const EnvOptions& toptions,
+    const InternalKeyComparator& internal_comparator,
+    const FileMetaData& file_meta,
+    std::shared_ptr<const TableProperties>* properties, bool no_io) {
+  Status s;
+  auto table_handle = file_meta.table_reader_handle;
+  // table already been pre-loaded?
+  if (table_handle) {
+    auto table = GetTableReaderFromHandle(table_handle);
+    *properties = table->GetTableProperties();
+    return s;
+  }
+
+  bool table_io;
+  s = FindTable(toptions, internal_comparator, file_meta.number,
+                file_meta.file_size, &table_handle, &table_io, no_io);
+  if (!s.ok()) {
+    return s;
+  }
+  assert(table_handle);
+  auto table = GetTableReaderFromHandle(table_handle);
+  *properties = table->GetTableProperties();
+  ReleaseHandle(table_handle);
+  return s;
+}

 bool TableCache::PrefixMayMatch(const ReadOptions& options,
-                                uint64_t file_number,
-                                uint64_t file_size,
-                                const Slice& internal_prefix,
-                                bool* table_io) {
-  Cache::Handle* handle = nullptr;
-  Status s = FindTable(storage_options_, file_number,
-                       file_size, &handle, table_io);
+                                const InternalKeyComparator& icomparator,
+                                const FileMetaData& file_meta,
+                                const Slice& internal_prefix, bool* table_io) {
  bool may_match = true;
-  if (s.ok()) {
-    TableReader* t =
-      reinterpret_cast<TableReader*>(cache_->Value(handle));
-    may_match = t->PrefixMayMatch(internal_prefix);
-    cache_->Release(handle);
+  auto table_handle = file_meta.table_reader_handle;
+  if (table_handle == nullptr) {
+    // Need to get table handle from file number
+    Status s = FindTable(storage_options_, icomparator, file_meta.number,
+                         file_meta.file_size, &table_handle, table_io);
+    if (!s.ok()) {
+      return may_match;
+    }
  }
+
+  auto table = GetTableReaderFromHandle(table_handle);
+  may_match = table->PrefixMayMatch(internal_prefix);
+
+  if (file_meta.table_reader_handle == nullptr) {
+    // Need to release handle if it is generated from here.
+    ReleaseHandle(table_handle);
+  }
+
  return may_match;
 }

@@ -12,16 +12,21 @@
 #pragma once
 #include <string>
 #include <stdint.h>
+
 #include "db/dbformat.h"
-#include "rocksdb/env.h"
-#include "rocksdb/cache.h"
 #include "port/port.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/env.h"
 #include "rocksdb/table.h"
+#include "table/table_reader.h"

 namespace rocksdb {

 class Env;
+struct FileMetaData;

+// TODO(sdong): try to come up with a better API to pass the file information
+//              other than simply passing FileMetaData.
 class TableCache {
 public:
  TableCache(const std::string& dbname, const Options* options,
@@ -35,10 +40,9 @@ class TableCache {
  // the returned iterator.  The returned "*tableptr" object is owned by
  // the cache and should not be deleted, and is valid for as long as the
  // returned iterator is live.
-  Iterator* NewIterator(const ReadOptions& options,
-                        const EnvOptions& toptions,
-                        uint64_t file_number,
-                        uint64_t file_size,
+  Iterator* NewIterator(const ReadOptions& options, const EnvOptions& toptions,
+                        const InternalKeyComparator& internal_comparator,
+                        const FileMetaData& file_meta,
                        TableReader** table_reader_ptr = nullptr,
                        bool for_compaction = false);

@@ -46,33 +50,52 @@ class TableCache {
  // call (*handle_result)(arg, found_key, found_value) repeatedly until
  // it returns false.
  Status Get(const ReadOptions& options,
-             uint64_t file_number,
-             uint64_t file_size,
-             const Slice& k,
-             void* arg,
-             bool (*handle_result)(void*, const Slice&, const Slice&, bool),
-             bool* table_io,
-             void (*mark_key_may_exist)(void*) = nullptr);
+             const InternalKeyComparator& internal_comparator,
+             const FileMetaData& file_meta, const Slice& k, void* arg,
+             bool (*handle_result)(void*, const ParsedInternalKey&,
+                                   const Slice&, bool),
+             bool* table_io, void (*mark_key_may_exist)(void*) = nullptr);

  // Determine whether the table may contain the specified prefix.  If
-  // the table index of blooms are not in memory, this may cause an I/O
-  bool PrefixMayMatch(const ReadOptions& options, uint64_t file_number,
-                      uint64_t file_size, const Slice& internal_prefix,
-                      bool* table_io);
+  // the table index or blooms are not in memory, this may cause an I/O
+  bool PrefixMayMatch(const ReadOptions& options,
+                      const InternalKeyComparator& internal_comparator,
+                      const FileMetaData& file_meta,
+                      const Slice& internal_prefix, bool* table_io);

  // Evict any entry for the specified file number
  void Evict(uint64_t file_number);

+  // Find table reader
+  Status FindTable(const EnvOptions& toptions,
+                   const InternalKeyComparator& internal_comparator,
+                   uint64_t file_number, uint64_t file_size, Cache::Handle**,
+                   bool* table_io = nullptr, const bool no_io = false);
+
+  // Get TableReader from a cache handle.
+  TableReader* GetTableReaderFromHandle(Cache::Handle* handle);
+
+  // Get the table properties of a given table.
+  // @no_io: indicates if we should load table to the cache if it is not present
+  //         in table cache yet.
+  // @returns: `properties` will be reset on success. Please note that we will
+  //            return Status::Incomplete() if table is not present in cache and
+  //            we set `no_io` to be true.
+  Status GetTableProperties(const EnvOptions& toptions,
+                            const InternalKeyComparator& internal_comparator,
+                            const FileMetaData& file_meta,
+                            std::shared_ptr<const TableProperties>* properties,
+                            bool no_io = false);
+
+  // Release the handle from a cache
+  void ReleaseHandle(Cache::Handle* handle);
+
 private:
  Env* const env_;
  const std::string dbname_;
  const Options* options_;
  const EnvOptions& storage_options_;
  std::shared_ptr<Cache> cache_;
-
-  Status FindTable(const EnvOptions& toptions, uint64_t file_number,
-                   uint64_t file_size, Cache::Handle**, bool* table_io=nullptr,
-                   const bool no_io = false);
 };

 }  // namespace rocksdb
@@ -10,87 +10,6 @@

 namespace rocksdb {

-namespace {
-  void AppendProperty(
-      std::string& props,
-      const std::string& key,
-      const std::string& value,
-      const std::string& prop_delim,
-      const std::string& kv_delim) {
-    props.append(key);
-    props.append(kv_delim);
-    props.append(value);
-    props.append(prop_delim);
-  }
-
-  template <class TValue>
-  void AppendProperty(
-      std::string& props,
-      const std::string& key,
-      const TValue& value,
-      const std::string& prop_delim,
-      const std::string& kv_delim) {
-    AppendProperty(
-        props, key, std::to_string(value), prop_delim, kv_delim
-    );
-  }
-}
-
-std::string TableProperties::ToString(
-    const std::string& prop_delim,
-    const std::string& kv_delim) const {
-  std::string result;
-  result.reserve(1024);
-
-  // Basic Info
-  AppendProperty(
-      result, "# data blocks", num_data_blocks, prop_delim, kv_delim
-  );
-  AppendProperty(result, "# entries", num_entries, prop_delim, kv_delim);
-
-  AppendProperty(result, "raw key size", raw_key_size, prop_delim, kv_delim);
-  AppendProperty(
-      result,
-      "raw average key size",
-      num_entries != 0 ?  1.0 * raw_key_size / num_entries : 0.0,
-      prop_delim,
-      kv_delim
-  );
-  AppendProperty(
-      result, "raw value size", raw_value_size, prop_delim, kv_delim
-  );
-  AppendProperty(
-      result,
-      "raw average value size",
-      num_entries != 0 ?  1.0 * raw_value_size / num_entries : 0.0,
-      prop_delim,
-      kv_delim
-  );
-
-  AppendProperty(result, "data block size", data_size, prop_delim, kv_delim);
-  AppendProperty(result, "index block size", index_size, prop_delim, kv_delim);
-  AppendProperty(
-      result, "filter block size", filter_size, prop_delim, kv_delim
-  );
-  AppendProperty(
-      result,
-      "(estimated) table size",
-      data_size + index_size + filter_size,
-      prop_delim,
-      kv_delim
-  );
-
-  AppendProperty(
-      result,
-      "filter policy name",
-      filter_policy_name.empty() ? std::string("N/A") : filter_policy_name,
-      prop_delim,
-      kv_delim
-  );
-
-  return result;
-}
-
 Status InternalKeyPropertiesCollector::Add(
    const Slice& key, const Slice& value) {
  ParsedInternalKey ikey;
@@ -106,7 +25,7 @@ Status InternalKeyPropertiesCollector::Add(
 }

 Status InternalKeyPropertiesCollector::Finish(
-    TableProperties::UserCollectedProperties* properties) {
+    UserCollectedProperties* properties) {
  assert(properties);
  assert(properties->find(
        InternalKeyTablePropertiesNames::kDeletedKeys) == properties->end());
@@ -118,7 +37,7 @@ Status InternalKeyPropertiesCollector::Finish(
  return Status::OK();
 }

-TableProperties::UserCollectedProperties
+UserCollectedProperties
 InternalKeyPropertiesCollector::GetReadableProperties() const {
  return {
    { "kDeletedKeys", std::to_string(deleted_keys_) }
@@ -137,11 +56,11 @@ Status UserKeyTablePropertiesCollector::Add(
 }

 Status UserKeyTablePropertiesCollector::Finish(
-    TableProperties::UserCollectedProperties* properties) {
+    UserCollectedProperties* properties) {
  return collector_->Finish(properties);
 }

-TableProperties::UserCollectedProperties
+UserCollectedProperties
 UserKeyTablePropertiesCollector::GetReadableProperties() const {
  return collector_->GetReadableProperties();
 }
@@ -151,7 +70,7 @@ const std::string InternalKeyTablePropertiesNames::kDeletedKeys
  = "rocksdb.deleted.keys";

 uint64_t GetDeletedKeys(
-    const TableProperties::UserCollectedProperties& props) {
+    const UserCollectedProperties& props) {
  auto pos = props.find(InternalKeyTablePropertiesNames::kDeletedKeys);
  if (pos == props.end()) {
    return 0;
@@ -24,15 +24,13 @@ class InternalKeyPropertiesCollector : public TablePropertiesCollector {
 public:
  virtual Status Add(const Slice& key, const Slice& value) override;

-  virtual Status Finish(
-      TableProperties::UserCollectedProperties* properties) override;
+  virtual Status Finish(UserCollectedProperties* properties) override;

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

-  TableProperties::UserCollectedProperties
-    GetReadableProperties() const override;
+  UserCollectedProperties GetReadableProperties() const override;

 private:
  uint64_t deleted_keys_ = 0;
@@ -61,13 +59,11 @@ class UserKeyTablePropertiesCollector : public TablePropertiesCollector {

  virtual Status Add(const Slice& key, const Slice& value) override;

-  virtual Status Finish(
-      TableProperties::UserCollectedProperties* properties) override;
+  virtual Status Finish(UserCollectedProperties* properties) override;

  virtual const char* Name() const override { return collector_->Name(); }

-  TableProperties::UserCollectedProperties
-    GetReadableProperties() const override;
+  UserCollectedProperties GetReadableProperties() const override;

 protected:
  std::shared_ptr<TablePropertiesCollector> collector_;
@@ -7,12 +7,14 @@
 #include <memory>
 #include <string>

-#include "db/dbformat.h"
 #include "db/db_impl.h"
+#include "db/dbformat.h"
 #include "db/table_properties_collector.h"
-#include "rocksdb/table_properties.h"
 #include "rocksdb/table.h"
 #include "table/block_based_table_factory.h"
+#include "table/meta_blocks.h"
+#include "table/plain_table_factory.h"
+#include "table/table_builder.h"
 #include "util/coding.h"
 #include "util/testharness.h"
 #include "util/testutil.h"
@@ -20,8 +22,6 @@
 namespace rocksdb {

 class TablePropertiesTest {
- private:
-  unique_ptr<TableReader> table_reader_;
 };

 // TODO(kailiu) the following classes should be moved to some more general
@@ -83,30 +83,13 @@ class DumbLogger : public Logger {
 };

 // Utilities test functions
-void MakeBuilder(
-    const Options& options,
-    std::unique_ptr<FakeWritableFile>* writable,
-    std::unique_ptr<TableBuilder>* builder) {
+void MakeBuilder(const Options& options,
+                 const InternalKeyComparator& internal_comparator,
+                 std::unique_ptr<FakeWritableFile>* writable,
+                 std::unique_ptr<TableBuilder>* builder) {
  writable->reset(new FakeWritableFile);
-  builder->reset(
-      options.table_factory->GetTableBuilder(options, writable->get(),
-                                             options.compression));
-}
-
-void OpenTable(
-    const Options& options,
-    const std::string& contents,
-    std::unique_ptr<TableReader>* table_reader) {
-
-  std::unique_ptr<RandomAccessFile> file(new FakeRandomeAccessFile(contents));
-  auto s = options.table_factory->GetTableReader(
-      options,
-      EnvOptions(),
-      std::move(file),
-      contents.size(),
-      table_reader
-  );
-  ASSERT_OK(s);
+  builder->reset(options.table_factory->NewTableBuilder(
+      options, internal_comparator, writable->get(), options.compression));
 }

 // Collects keys that starts with "A" in a table.
@@ -114,10 +97,10 @@ class RegularKeysStartWithA: public TablePropertiesCollector {
 public:
   const char* Name() const { return "RegularKeysStartWithA"; }

-   Status Finish(TableProperties::UserCollectedProperties* properties) {
+   Status Finish(UserCollectedProperties* properties) {
     std::string encoded;
     PutVarint32(&encoded, count_);
-     *properties = TableProperties::UserCollectedProperties {
+     *properties = UserCollectedProperties {
       { "TablePropertiesTest", "Rocksdb" },
       { "Count", encoded }
     };
@@ -132,9 +115,8 @@ class RegularKeysStartWithA: public TablePropertiesCollector {
     return Status::OK();
   }

-  virtual TableProperties::UserCollectedProperties
-    GetReadableProperties() const {
-      return {};
+  virtual UserCollectedProperties GetReadableProperties() const {
+    return UserCollectedProperties{};
  }


@@ -142,23 +124,66 @@ class RegularKeysStartWithA: public TablePropertiesCollector {
  uint32_t count_ = 0;
 };

-TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
-  Options options;
-
+extern uint64_t kBlockBasedTableMagicNumber;
+extern uint64_t kPlainTableMagicNumber;
+void TestCustomizedTablePropertiesCollector(
+    uint64_t magic_number, bool encode_as_internal, const Options& options,
+    const InternalKeyComparator& internal_comparator) {
  // make sure the entries will be inserted with order.
  std::map<std::string, std::string> kvs = {
-    {"About",     "val5"},  // starts with 'A'
-    {"Abstract",  "val2"},  // starts with 'A'
-    {"Around",    "val7"},  // starts with 'A'
-    {"Beyond",    "val3"},
-    {"Builder",   "val1"},
-    {"Cancel",    "val4"},
-    {"Find",      "val6"},
+    {"About   ", "val5"},  // starts with 'A'
+    {"Abstract", "val2"},  // starts with 'A'
+    {"Around  ", "val7"},  // starts with 'A'
+    {"Beyond  ", "val3"},
+    {"Builder ", "val1"},
+    {"Cancel  ", "val4"},
+    {"Find    ", "val6"},
  };

+  // -- Step 1: build table
+  std::unique_ptr<TableBuilder> builder;
+  std::unique_ptr<FakeWritableFile> writable;
+  MakeBuilder(options, internal_comparator, &writable, &builder);
+
+  for (const auto& kv : kvs) {
+    if (encode_as_internal) {
+      InternalKey ikey(kv.first, 0, ValueType::kTypeValue);
+      builder->Add(ikey.Encode(), kv.second);
+    } else {
+      builder->Add(kv.first, kv.second);
+    }
+  }
+  ASSERT_OK(builder->Finish());
+
+  // -- Step 2: Read properties
+  FakeRandomeAccessFile readable(writable->contents());
+  TableProperties* props;
+  Status s = ReadTableProperties(
+      &readable,
+      writable->contents().size(),
+      magic_number,
+      Env::Default(),
+      nullptr,
+      &props
+  );
+  std::unique_ptr<TableProperties> props_guard(props);
+  ASSERT_OK(s);
+
+  auto user_collected = props->user_collected_properties;
+
+  ASSERT_EQ("Rocksdb", user_collected.at("TablePropertiesTest"));
+
+  uint32_t starts_with_A = 0;
+  Slice key(user_collected.at("Count"));
+  ASSERT_TRUE(GetVarint32(&key, &starts_with_A));
+  ASSERT_EQ(3u, starts_with_A);
+}
+
+TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
  // Test properties collectors with internal keys or regular keys
+  // for block based table
  for (bool encode_as_internal : { true, false }) {
-    // -- Step 1: build table
+    Options options;
    auto collector = new RegularKeysStartWithA();
    if (encode_as_internal) {
      options.table_properties_collectors = {
@@ -168,95 +193,110 @@ TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
      options.table_properties_collectors.resize(1);
      options.table_properties_collectors[0].reset(collector);
    }
-    std::unique_ptr<TableBuilder> builder;
-    std::unique_ptr<FakeWritableFile> writable;
-    MakeBuilder(options, &writable, &builder);
+    test::PlainInternalKeyComparator ikc(options.comparator);
+    TestCustomizedTablePropertiesCollector(kBlockBasedTableMagicNumber,
+                                           encode_as_internal, options, ikc);
+  }

-    for (const auto& kv : kvs) {
-      if (encode_as_internal) {
-        InternalKey ikey(kv.first, 0, ValueType::kTypeValue);
-        builder->Add(ikey.Encode(), kv.second);
-      } else {
-        builder->Add(kv.first, kv.second);
-      }
-    }
-    ASSERT_OK(builder->Finish());
+  // test plain table
+  Options options;
+  options.table_properties_collectors.push_back(
+      std::make_shared<RegularKeysStartWithA>()
+  );
+  options.table_factory = std::make_shared<PlainTableFactory>(8, 8, 0);
+  test::PlainInternalKeyComparator ikc(options.comparator);
+  TestCustomizedTablePropertiesCollector(kPlainTableMagicNumber, true, options,
+                                         ikc);
+}

-    // -- Step 2: Open table
-    std::unique_ptr<TableReader> table_reader;
-    OpenTable(options, writable->contents(), &table_reader);
-    const auto& properties =
-      table_reader->GetTableProperties().user_collected_properties;
+void TestInternalKeyPropertiesCollector(
+    uint64_t magic_number,
+    bool sanitized,
+    std::shared_ptr<TableFactory> table_factory) {
+  InternalKey keys[] = {
+    InternalKey("A       ", 0, ValueType::kTypeValue),
+    InternalKey("B       ", 0, ValueType::kTypeValue),
+    InternalKey("C       ", 0, ValueType::kTypeValue),
+    InternalKey("W       ", 0, ValueType::kTypeDeletion),
+    InternalKey("X       ", 0, ValueType::kTypeDeletion),
+    InternalKey("Y       ", 0, ValueType::kTypeDeletion),
+    InternalKey("Z       ", 0, ValueType::kTypeDeletion),
+  };

-    ASSERT_EQ("Rocksdb", properties.at("TablePropertiesTest"));
+  std::unique_ptr<TableBuilder> builder;
+  std::unique_ptr<FakeWritableFile> writable;
+  Options options;
+  test::PlainInternalKeyComparator pikc(options.comparator);

+  options.table_factory = table_factory;
+  if (sanitized) {
+    options.table_properties_collectors = {
+      std::make_shared<RegularKeysStartWithA>()
+    };
+    // with sanitization, even regular properties collector will be able to
+    // handle internal keys.
+    auto comparator = options.comparator;
+    // HACK: Set options.info_log to avoid writing log in
+    // SanitizeOptions().
+    options.info_log = std::make_shared<DumbLogger>();
+    options = SanitizeOptions("db",            // just a place holder
+                              &pikc, nullptr,  // don't care filter policy
+                              options);
+    options.comparator = comparator;
+  } else {
+    options.table_properties_collectors = {
+      std::make_shared<InternalKeyPropertiesCollector>()
+    };
+  }
+
+  MakeBuilder(options, pikc, &writable, &builder);
+  for (const auto& k : keys) {
+    builder->Add(k.Encode(), "val");
+  }
+
+  ASSERT_OK(builder->Finish());
+
+  FakeRandomeAccessFile readable(writable->contents());
+  TableProperties* props;
+  Status s = ReadTableProperties(
+      &readable,
+      writable->contents().size(),
+      magic_number,
+      Env::Default(),
+      nullptr,
+      &props
+  );
+  ASSERT_OK(s);
+
+  std::unique_ptr<TableProperties> props_guard(props);
+  auto user_collected = props->user_collected_properties;
+  uint64_t deleted = GetDeletedKeys(user_collected);
+  ASSERT_EQ(4u, deleted);
+
+  if (sanitized) {
    uint32_t starts_with_A = 0;
-    Slice key(properties.at("Count"));
+    Slice key(user_collected.at("Count"));
    ASSERT_TRUE(GetVarint32(&key, &starts_with_A));
-    ASSERT_EQ(3u, starts_with_A);
+    ASSERT_EQ(1u, starts_with_A);
  }
 }

 TEST(TablePropertiesTest, InternalKeyPropertiesCollector) {
-  InternalKey keys[] = {
-    InternalKey("A", 0, ValueType::kTypeValue),
-    InternalKey("B", 0, ValueType::kTypeValue),
-    InternalKey("C", 0, ValueType::kTypeValue),
-    InternalKey("W", 0, ValueType::kTypeDeletion),
-    InternalKey("X", 0, ValueType::kTypeDeletion),
-    InternalKey("Y", 0, ValueType::kTypeDeletion),
-    InternalKey("Z", 0, ValueType::kTypeDeletion),
-  };
-
-  for (bool sanitized : { false, true }) {
-    std::unique_ptr<TableBuilder> builder;
-    std::unique_ptr<FakeWritableFile> writable;
-    Options options;
-    if (sanitized) {
-      options.table_properties_collectors = {
-        std::make_shared<RegularKeysStartWithA>()
-      };
-      // with sanitization, even regular properties collector will be able to
-      // handle internal keys.
-      auto comparator = options.comparator;
-      // HACK: Set options.info_log to avoid writing log in
-      // SanitizeOptions().
-      options.info_log = std::make_shared<DumbLogger>();
-      options = SanitizeOptions(
-          "db",  // just a place holder
-          nullptr,  // with skip internal key comparator
-          nullptr,  // don't care filter policy
-          options
-      );
-      options.comparator = comparator;
-    } else {
-      options.table_properties_collectors = {
-        std::make_shared<InternalKeyPropertiesCollector>()
-      };
-    }
-
-    MakeBuilder(options, &writable, &builder);
-    for (const auto& k : keys) {
-      builder->Add(k.Encode(), "val");
-    }
-
-    ASSERT_OK(builder->Finish());
-
-    std::unique_ptr<TableReader> table_reader;
-    OpenTable(options, writable->contents(), &table_reader);
-    const auto& properties =
-      table_reader->GetTableProperties().user_collected_properties;
-
-    uint64_t deleted = GetDeletedKeys(properties);
-    ASSERT_EQ(4u, deleted);
-
-    if (sanitized) {
-      uint32_t starts_with_A = 0;
-      Slice key(properties.at("Count"));
-      ASSERT_TRUE(GetVarint32(&key, &starts_with_A));
-      ASSERT_EQ(1u, starts_with_A);
-    }
-  }
+  TestInternalKeyPropertiesCollector(
+      kBlockBasedTableMagicNumber,
+      true /* sanitize */,
+      std::make_shared<BlockBasedTableFactory>()
+  );
+  TestInternalKeyPropertiesCollector(
+      kBlockBasedTableMagicNumber,
+      true /* not sanitize */,
+      std::make_shared<BlockBasedTableFactory>()
+  );
+  TestInternalKeyPropertiesCollector(
+      kPlainTableMagicNumber,
+      false /* not sanitize */,
+      std::make_shared<PlainTableFactory>(8, 8, 0)
+  );
 }

 }  // namespace rocksdb
@@ -155,7 +155,7 @@ bool TailingIterator::IsCurrentVersion() const {
 }

 bool TailingIterator::IsSamePrefix(const Slice& target) const {
-  const SliceTransform* extractor = db_->options_.prefix_extractor;
+  const SliceTransform* extractor = db_->options_.prefix_extractor.get();

  assert(extractor);
  assert(is_prev_set_);
@@ -9,23 +9,22 @@
 namespace rocksdb {

 TransactionLogIteratorImpl::TransactionLogIteratorImpl(
-                           const std::string& dir,
-                           const Options* options,
-                           const EnvOptions& soptions,
-                           const SequenceNumber seq,
-                           std::unique_ptr<VectorLogPtr> files,
-                           DBImpl const * const dbimpl) :
-    dir_(dir),
-    options_(options),
-    soptions_(soptions),
-    startingSequenceNumber_(seq),
-    files_(std::move(files)),
-    started_(false),
-    isValid_(false),
-    currentFileIndex_(0),
-    currentBatchSeq_(0),
-    currentLastSeq_(0),
-    dbimpl_(dbimpl) {
+    const std::string& dir, const Options* options,
+    const TransactionLogIterator::ReadOptions& read_options,
+    const EnvOptions& soptions, const SequenceNumber seq,
+    std::unique_ptr<VectorLogPtr> files, DBImpl const* const dbimpl)
+    : dir_(dir),
+      options_(options),
+      read_options_(read_options),
+      soptions_(soptions),
+      startingSequenceNumber_(seq),
+      files_(std::move(files)),
+      started_(false),
+      isValid_(false),
+      currentFileIndex_(0),
+      currentBatchSeq_(0),
+      currentLastSeq_(0),
+      dbimpl_(dbimpl) {
  assert(files_ != nullptr);
  assert(dbimpl_ != nullptr);

@@ -49,9 +48,6 @@ Status TransactionLogIteratorImpl::OpenLogFile(
      //  Try the archive dir, as it could have moved in the meanwhile.
      fname = ArchivedLogFileName(dir_, logFile->LogNumber());
      status = env->NewSequentialFile(fname, file, soptions_);
-      if (!status.ok()) {
-        return Status::IOError("Requested file not present in the dir");
-      }
    }
    return status;
  }
@@ -190,7 +186,7 @@ void TransactionLogIteratorImpl::NextImpl(bool internal) {
      if (currentLastSeq_ == dbimpl_->GetLatestSequenceNumber()) {
        currentStatus_ = Status::OK();
      } else {
-        currentStatus_ = Status::IOError("NO MORE DATA LEFT");
+        currentStatus_ = Status::Corruption("NO MORE DATA LEFT");
      }
      return;
    }
@@ -256,9 +252,8 @@ Status TransactionLogIteratorImpl::OpenLogReader(const LogFile* logFile) {
    return status;
  }
  assert(file);
-  currentLogReader_.reset(
-    new log::Reader(std::move(file), &reporter_, true, 0)
-  );
+  currentLogReader_.reset(new log::Reader(std::move(file), &reporter_,
+                                          read_options_.verify_checksums_, 0));
  return Status::OK();
 }
 }  //  namespace rocksdb
@@ -66,12 +66,11 @@ class LogFileImpl : public LogFile {

 class TransactionLogIteratorImpl : public TransactionLogIterator {
 public:
-  TransactionLogIteratorImpl(const std::string& dir,
-                             const Options* options,
-                             const EnvOptions& soptions,
-                             const SequenceNumber seqNum,
-                             std::unique_ptr<VectorLogPtr> files,
-                             DBImpl const * const dbimpl);
+  TransactionLogIteratorImpl(
+      const std::string& dir, const Options* options,
+      const TransactionLogIterator::ReadOptions& read_options,
+      const EnvOptions& soptions, const SequenceNumber seqNum,
+      std::unique_ptr<VectorLogPtr> files, DBImpl const* const dbimpl);

  virtual bool Valid();

@@ -84,6 +83,7 @@ class TransactionLogIteratorImpl : public TransactionLogIterator {
 private:
  const std::string& dir_;
  const Options* options_;
+  const TransactionLogIterator::ReadOptions read_options_;
  const EnvOptions& soptions_;
  SequenceNumber startingSequenceNumber_;
  std::unique_ptr<VectorLogPtr> files_;
@@ -28,7 +28,7 @@ enum Tag {
  kPrevLogNumber        = 9,

  // these are new formats divergent from open source leveldb
-  kNewFile2             = 100  // store smallest & largest seqno
+  kNewFile2             = 100,  // store smallest & largest seqno
 };

 void VersionEdit::Clear() {
@@ -69,12 +69,10 @@ void VersionEdit::EncodeTo(std::string* dst) const {
    PutVarint64(dst, last_sequence_);
  }

-  for (DeletedFileSet::const_iterator iter = deleted_files_.begin();
-       iter != deleted_files_.end();
-       ++iter) {
+  for (const auto& deleted : deleted_files_) {
    PutVarint32(dst, kDeletedFile);
-    PutVarint32(dst, iter->first);   // level
-    PutVarint64(dst, iter->second);  // file number
+    PutVarint32(dst, deleted.first /* level */);
+    PutVarint64(dst, deleted.second /* file number */);
  }

  for (size_t i = 0; i < new_files_.size(); i++) {
@@ -11,6 +11,7 @@
 #include <set>
 #include <utility>
 #include <vector>
+#include "rocksdb/cache.h"
 #include "db/dbformat.h"

 namespace rocksdb {
@@ -28,8 +29,14 @@ struct FileMetaData {
  SequenceNumber smallest_seqno;// The smallest seqno in this file
  SequenceNumber largest_seqno; // The largest seqno in this file

-  FileMetaData() : refs(0), allowed_seeks(1 << 30), file_size(0),
-                   being_compacted(false) { }
+  // Needs to be disposed when refs becomes 0.
+  Cache::Handle* table_reader_handle;
+
+  FileMetaData(uint64_t number, uint64_t file_size) :
+      refs(0), allowed_seeks(1 << 30), number(number), file_size(file_size),
+      being_compacted(false), table_reader_handle(nullptr) {
+  }
+  FileMetaData() : FileMetaData(0, 0) { }
 };

 class VersionEdit {
@@ -69,6 +76,7 @@ class VersionEdit {
               const InternalKey& largest,
               const SequenceNumber& smallest_seqno,
               const SequenceNumber& largest_seqno) {
+    assert(smallest_seqno <= largest_seqno);
    FileMetaData f;
    f.number = file;
    f.file_size = file_size;
@@ -76,13 +84,12 @@ class VersionEdit {
    f.largest = largest;
    f.smallest_seqno = smallest_seqno;
    f.largest_seqno = largest_seqno;
-    assert(smallest_seqno <= largest_seqno);
    new_files_.push_back(std::make_pair(level, f));
  }

  // Delete the specified "file" from the specified "level".
  void DeleteFile(int level, uint64_t file) {
-    deleted_files_.insert(std::make_pair(level, file));
+    deleted_files_.insert({level, file});
  }

  // Number of edits
@@ -98,7 +105,7 @@ class VersionEdit {
 private:
  friend class VersionSet;

-  typedef std::set< std::pair<int, uint64_t> > DeletedFileSet;
+  typedef std::set< std::pair<int, uint64_t>> DeletedFileSet;

  bool GetLevel(Slice* input, int* level, const char** msg);

@@ -23,6 +23,7 @@
 #include <set>
 #include <vector>
 #include <deque>
+#include <atomic>
 #include "db/dbformat.h"
 #include "db/version_edit.h"
 #include "port/port.h"
@@ -37,11 +38,13 @@ namespace log { class Writer; }
 class Compaction;
 class CompactionPicker;
 class Iterator;
+class LogBuffer;
+class LookupKey;
 class MemTable;
+class MergeContext;
 class TableCache;
 class Version;
 class VersionSet;
-class MergeContext;

 // Return the smallest index i such that files[i]->largest >= key.
 // Return files.size() if there is no such file.
@@ -81,8 +84,8 @@ class Version {
  };
  void Get(const ReadOptions&, const LookupKey& key, std::string* val,
           Status* status, MergeContext* merge_context,
-           GetStats* stats, const Options& db_option, bool* value_found =
-               nullptr);
+           GetStats* stats, const Options& db_option,
+           bool* value_found = nullptr);

  // Adds "stats" into the current state.  Returns true if a new
  // compaction may need to be triggered, false otherwise.
@@ -91,13 +94,16 @@ class Version {

  // Updates internal structures that keep track of compaction scores
  // We use compaction scores to figure out which compaction to do next
-  // Also pre-sorts level0 files for Get()
-  void Finalize(std::vector<uint64_t>& size_being_compacted);
+  // REQUIRES: If Version is not yet saved to current_, it can be called without
+  // a lock. Once a version is saved to current_, call only with mutex held
+  void ComputeCompactionScore(std::vector<uint64_t>& size_being_compacted);

  // Reference count management (so Versions do not disappear out from
  // under live iterators)
  void Ref();
-  void Unref();
+  // Decrease reference count. Delete the object if no reference left
+  // and return true. Otherwise, return false.
+  bool Unref();

  // Returns true iff some level needs a compaction.
  bool NeedsCompaction() const;
@@ -186,6 +192,12 @@ class Version {
  // Returns the version nuber of this version
  uint64_t GetVersionNumber() const { return version_number_; }

+  // REQUIRES: lock is held
+  // On success, *props will be populated with all SSTables' table properties.
+  // The keys of `props` are the sst file name, the values of `props` are the
+  // tables' propertis, represented as shared_ptr.
+  Status GetPropertiesOfAllTables(TablePropertiesCollection* props);
+
  // used to sort files by size
  struct Fsize {
    int index;
@@ -225,7 +237,7 @@ class Version {
  // but files in each level are now sorted based on file
  // size. The file with the largest size is at the front.
  // This vector stores the index of the file from files_.
-  std::vector< std::vector<int> > files_by_size_;
+  std::vector<std::vector<int>> files_by_size_;

  // An index into files_by_size_ that specifies the first
  // file that is not yet compacted
@@ -316,6 +328,10 @@ class VersionSet {
  // Return the current manifest file number
  uint64_t ManifestFileNumber() const { return manifest_file_number_; }

+  uint64_t PendingManifestFileNumber() const {
+    return pending_manifest_file_number_;
+  }
+
  // Allocate and return a new file number
  uint64_t NewFileNumber() { return next_file_number_++; }

@@ -355,7 +371,7 @@ class VersionSet {
  // Returns nullptr if there is no compaction to be done.
  // Otherwise returns a pointer to a heap-allocated object that
  // describes the compaction.  Caller should delete the result.
-  Compaction* PickCompaction();
+  Compaction* PickCompaction(LogBuffer* log_buffer);

  // Return a compaction object for compacting the range [begin,end] in
  // the specified level.  Returns nullptr if there is nothing in that
@@ -406,7 +422,7 @@ class VersionSet {
  void ReleaseCompactionFiles(Compaction* c, Status status);

  Status GetMetadataForFile(
-    uint64_t number, int *filelevel, FileMetaData *metadata);
+    uint64_t number, int *filelevel, FileMetaData **metadata);

  void GetLiveFilesMetaData(
    std::vector<LiveFileMetaData> *metadata);
@@ -425,7 +441,8 @@ class VersionSet {

  void AppendVersion(Version* v);

-  bool ManifestContains(const std::string& record) const;
+  bool ManifestContains(uint64_t manifest_file_number,
+                        const std::string& record) const;

  Env* const env_;
  const std::string dbname_;
@@ -434,6 +451,7 @@ class VersionSet {
  const InternalKeyComparator icmp_;
  uint64_t next_file_number_;
  uint64_t manifest_file_number_;
+  uint64_t pending_manifest_file_number_;
  std::atomic<uint64_t> last_sequence_;
  uint64_t log_number_;
  uint64_t prev_log_number_;  // 0 or backing store for memtable being compacted
@@ -117,7 +117,7 @@ Status WriteBatch::Iterate(Handler* handler) const {
        return Status::Corruption("unknown WriteBatch tag");
    }
  }
-  if (found != WriteBatchInternal::Count(this)) {
+ if (found != WriteBatchInternal::Count(this)) {
    return Status::Corruption("WriteBatch has wrong count");
  } else {
    return Status::OK();
@@ -196,14 +196,46 @@ class MemTableInserter : public WriteBatch::Handler {
  }

  virtual void Put(const Slice& key, const Slice& value) {
-    if (options_->inplace_update_support
-        && mem_->Update(sequence_, kTypeValue, key, value)) {
+    if (!options_->inplace_update_support) {
+      mem_->Add(sequence_, kTypeValue, key, value);
+    } else if (options_->inplace_callback == nullptr) {
+      mem_->Update(sequence_, key, value);
      RecordTick(options_->statistics.get(), NUMBER_KEYS_UPDATED);
    } else {
-      mem_->Add(sequence_, kTypeValue, key, value);
+      if (mem_->UpdateCallback(sequence_, key, value, *options_)) {
+      } else {
+        // key not found in memtable. Do sst get, update, add
+        SnapshotImpl read_from_snapshot;
+        read_from_snapshot.number_ = sequence_;
+        ReadOptions ropts;
+        ropts.snapshot = &read_from_snapshot;
+
+        std::string prev_value;
+        std::string merged_value;
+        Status s = db_->Get(ropts, key, &prev_value);
+        char* prev_buffer = const_cast<char*>(prev_value.c_str());
+        uint32_t prev_size = prev_value.size();
+        auto status =
+          options_->inplace_callback(s.ok() ? prev_buffer: nullptr,
+                                     s.ok() ? &prev_size: nullptr,
+                                     value, &merged_value);
+        if (status == UpdateStatus::UPDATED_INPLACE) {
+          // prev_value is updated in-place with final value.
+          mem_->Add(sequence_, kTypeValue, key, Slice(prev_buffer, prev_size));
+          RecordTick(options_->statistics.get(), NUMBER_KEYS_WRITTEN);
+        } else if (status == UpdateStatus::UPDATED) {
+          // merged_value contains the final value.
+          mem_->Add(sequence_, kTypeValue, key, Slice(merged_value));
+          RecordTick(options_->statistics.get(), NUMBER_KEYS_WRITTEN);
+        }
+      }
    }
+    // Since all Puts are logged in trasaction logs (if enabled), always bump
+    // sequence number. Even if the update eventually fails and does not result
+    // in memtable add/update.
    sequence_++;
  }
+
  virtual void Merge(const Slice& key, const Slice& value) {
    bool perform_merge = false;

@@ -57,7 +57,7 @@ static std::string PrintContents(WriteBatch* b) {
        state.append(")");
        count++;
        break;
-      case kTypeLogData:
+      default:
        assert(false);
        break;
    }
@@ -609,13 +609,13 @@ key-value during background compaction.
 </ul>
 <p>
 Other options impacting performance of compactions and when they get triggered
-are: 
+are:
 <ul>
 <p>
-<li> <code>Options::access_hint_on_compaction_start</code> - Specify the file access 
+<li> <code>Options::access_hint_on_compaction_start</code> - Specify the file access
 pattern once a compaction is started. It will be applied to all input files of a compaction. Default: NORMAL
 <p>
-<li> <code>Options::level0_file_num_compaction_trigger</code> -  Number of files to trigger level-0 compaction. 
+<li> <code>Options::level0_file_num_compaction_trigger</code> -  Number of files to trigger level-0 compaction.
 A negative value means that level-0 compaction will not be triggered by number of files at all.
 <p>
 <li> <code>Options::max_mem_compaction_level</code> -  Maximum level to which a new compacted memtable is pushed if it
@@ -623,7 +623,7 @@ does not create overlap.  We try to push to level 2 to avoid the relatively expe
 expensive manifest file operations.  We do not push all the way to the largest level since that can generate a lot of wasted disk
 space if the same key space is being repeatedly overwritten.
 <p>
-<li> <code>Options::target_file_size_base</code> and <code>Options::target_file_size_multiplier</code> - 
+<li> <code>Options::target_file_size_base</code> and <code>Options::target_file_size_multiplier</code> -
 Target file size for compaction.  target_file_size_base is per-file size for level-1.
 Target file size for level L can be calculated by target_file_size_base * (target_file_size_multiplier ^ (L-1))
 For example, if target_file_size_base is 2MB and target_file_size_multiplier is 10, then each file on level-1 will
@@ -698,7 +698,7 @@ Default: kCompactionStopStyleTotalSize
 A thread pool is associated with Env environment object. The client has to create a thread pool by setting the number of background
 threads using method <code>Env::SetBackgroundThreads()</code> defined in <code>rocksdb/env.h</code>.
 We use the thread pool for compactions and memtable flushes.
-Since memtable flushes are in critical code path (stalling memtable flush can stall writes, increasing p99), we suggest 
+Since memtable flushes are in critical code path (stalling memtable flush can stall writes, increasing p99), we suggest
 having two thread pools - with priorities HIGH and LOW. Memtable flushes can be set up to be scheduled on HIGH thread pool.
 There are two options available for configuration of background compactions and flushes:
 <ul>
@@ -779,9 +779,9 @@ implementation.  See <code>rocksdb/util/env_posix.h</code> for an example.
 <p>
 To be able to efficiently tune your application, it is always helpful if you
 have access to usage statistics. You can collect those statistics by setting
-<code>Options::table_stats_collectors</code> or
+<code>Options::table_properties_collectors</code> or
 <code>Options::statistics</code>. For more information, refer to
-<code>rocksdb/table_stats.h</code> and <code>rocksdb/statistics.h</code>.
+<code>rocksdb/table_properties.h</code> and <code>rocksdb/statistics.h</code>.
 These should not add significant overhead to your application and we
 recommend exporting them to other monitoring tools.

@@ -47,7 +47,7 @@ private:
 class HdfsEnv : public Env {

 public:
-  HdfsEnv(const std::string& fsname) : fsname_(fsname) {
+  explicit HdfsEnv(const std::string& fsname) : fsname_(fsname) {
    posixEnv = Env::Default();
    fileSys_ = connectToPath(fsname_);
  }
@@ -108,6 +108,13 @@ class HdfsEnv : public Env {
    posixEnv->StartThread(function, arg);
  }

+  virtual void WaitForJoin() { posixEnv->WaitForJoin(); }
+
+  virtual unsigned int GetThreadPoolQueueLen(Priority pri = LOW) const
+      override {
+    return posixEnv->GetThreadPoolQueueLen(pri);
+  }
+
  virtual Status GetTestDirectory(std::string* path) {
    return posixEnv->GetTestDirectory(path);
  }
@@ -161,7 +168,7 @@ class HdfsEnv : public Env {
   */
  hdfsFS connectToPath(const std::string& uri) {
    if (uri.empty()) {
-      return NULL;
+      return nullptr;
    }
    if (uri.find(kProto) != 0) {
      // uri doesn't start with hdfs:// -> use default:0, which is special
@@ -218,10 +225,10 @@ static const Status notsup;
 class HdfsEnv : public Env {

 public:
-  HdfsEnv(const std::string& fsname) {
+  explicit HdfsEnv(const std::string& fsname) {
    fprintf(stderr, "You have not build rocksdb with HDFS support\n");
    fprintf(stderr, "Please see hdfs/README for details\n");
-    throw new std::exception();
+    throw std::exception();
  }

  virtual ~HdfsEnv() {
@@ -288,6 +295,12 @@ class HdfsEnv : public Env {

  virtual void StartThread(void (*function)(void* arg), void* arg) {}

+  virtual void WaitForJoin() {}
+
+  virtual unsigned int GetThreadPoolQueueLen(Priority pri = LOW) const {
+    return 0;
+  }
+
  virtual Status GetTestDirectory(std::string* path) {return notsup;}

  virtual uint64_t NowMicros() {return 0;}
@@ -1,45 +0,0 @@
-// Copyright (c) 2013, 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.
-// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file. See the AUTHORS file for names of contributors.
-//
-// Arena class defines memory allocation methods. It's used by memtable and
-// skiplist.
-
-#ifndef STORAGE_ROCKSDB_INCLUDE_ARENA_H_
-#define STORAGE_ROCKSDB_INCLUDE_ARENA_H_
-
-#include <limits>
-#include <memory>
-
-namespace rocksdb {
-
-class Arena {
- public:
-  Arena() {};
-  virtual ~Arena() {};
-
-  // Return a pointer to a newly allocated memory block of "bytes" bytes.
-  virtual char* Allocate(size_t bytes) = 0;
-
-  // Allocate memory with the normal alignment guarantees provided by malloc.
-  virtual char* AllocateAligned(size_t bytes) = 0;
-
-  // Returns an estimate of the total memory used by arena.
-  virtual const size_t ApproximateMemoryUsage() = 0;
-
-  // Returns the total number of bytes in all blocks allocated so far.
-  virtual const size_t MemoryAllocatedBytes() = 0;
-
- private:
-  // No copying allowed
-  Arena(const Arena&);
-  void operator=(const Arena&);
-};
-
-}  // namespace rocksdb
-
-#endif  // STORAGE_ROCKSDB_INCLUDE_ARENA_H_
@@ -54,23 +54,27 @@ extern "C" {

 /* Exported types */

-typedef struct rocksdb_t               rocksdb_t;
-typedef struct rocksdb_cache_t         rocksdb_cache_t;
-typedef struct rocksdb_comparator_t    rocksdb_comparator_t;
-typedef struct rocksdb_env_t           rocksdb_env_t;
-typedef struct rocksdb_filelock_t      rocksdb_filelock_t;
-typedef struct rocksdb_filterpolicy_t  rocksdb_filterpolicy_t;
-typedef struct rocksdb_iterator_t      rocksdb_iterator_t;
-typedef struct rocksdb_logger_t        rocksdb_logger_t;
-typedef struct rocksdb_options_t       rocksdb_options_t;
-typedef struct rocksdb_randomfile_t    rocksdb_randomfile_t;
-typedef struct rocksdb_readoptions_t   rocksdb_readoptions_t;
-typedef struct rocksdb_seqfile_t       rocksdb_seqfile_t;
-typedef struct rocksdb_snapshot_t      rocksdb_snapshot_t;
-typedef struct rocksdb_writablefile_t  rocksdb_writablefile_t;
-typedef struct rocksdb_writebatch_t    rocksdb_writebatch_t;
-typedef struct rocksdb_writeoptions_t  rocksdb_writeoptions_t;
+typedef struct rocksdb_t                 rocksdb_t;
+typedef struct rocksdb_cache_t           rocksdb_cache_t;
+typedef struct rocksdb_comparator_t      rocksdb_comparator_t;
+typedef struct rocksdb_env_t             rocksdb_env_t;
+typedef struct rocksdb_filelock_t        rocksdb_filelock_t;
+typedef struct rocksdb_filterpolicy_t    rocksdb_filterpolicy_t;
+typedef struct rocksdb_flushoptions_t    rocksdb_flushoptions_t;
+typedef struct rocksdb_iterator_t        rocksdb_iterator_t;
+typedef struct rocksdb_logger_t          rocksdb_logger_t;
+typedef struct rocksdb_mergeoperator_t   rocksdb_mergeoperator_t;
+typedef struct rocksdb_options_t         rocksdb_options_t;
+typedef struct rocksdb_randomfile_t      rocksdb_randomfile_t;
+typedef struct rocksdb_readoptions_t     rocksdb_readoptions_t;
+typedef struct rocksdb_seqfile_t         rocksdb_seqfile_t;
+typedef struct rocksdb_slicetransform_t  rocksdb_slicetransform_t;
+typedef struct rocksdb_snapshot_t        rocksdb_snapshot_t;
+typedef struct rocksdb_writablefile_t    rocksdb_writablefile_t;
+typedef struct rocksdb_writebatch_t      rocksdb_writebatch_t;
+typedef struct rocksdb_writeoptions_t    rocksdb_writeoptions_t;
 typedef struct rocksdb_universal_compaction_options_t rocksdb_universal_compaction_options_t;
+typedef struct rocksdb_livefiles_t     rocksdb_livefiles_t;

 /* DB operations */

@@ -94,6 +98,13 @@ extern void rocksdb_delete(
    const char* key, size_t keylen,
    char** errptr);

+extern void rocksdb_merge(
+    rocksdb_t* db,
+    const rocksdb_writeoptions_t* options,
+    const char* key, size_t keylen,
+    const char* val, size_t vallen,
+    char** errptr);
+
 extern void rocksdb_write(
    rocksdb_t* db,
    const rocksdb_writeoptions_t* options,
@@ -138,6 +149,27 @@ extern void rocksdb_compact_range(
    const char* start_key, size_t start_key_len,
    const char* limit_key, size_t limit_key_len);

+extern void rocksdb_delete_file(
+    rocksdb_t* db,
+    const char* name);
+
+extern const rocksdb_livefiles_t* rocksdb_livefiles(
+    rocksdb_t* db);
+
+extern void rocksdb_flush(
+    rocksdb_t* db,
+    const rocksdb_flushoptions_t* options,
+    char** errptr);
+
+extern void rocksdb_disable_file_deletions(
+    rocksdb_t* db,
+    char** errptr);
+
+extern void rocksdb_enable_file_deletions(
+    rocksdb_t* db,
+    unsigned char force,
+    char** errptr);
+
 /* Management operations */

 extern void rocksdb_destroy_db(
@@ -168,10 +200,15 @@ extern void rocksdb_iter_get_error(const rocksdb_iterator_t*, char** errptr);
 extern rocksdb_writebatch_t* rocksdb_writebatch_create();
 extern void rocksdb_writebatch_destroy(rocksdb_writebatch_t*);
 extern void rocksdb_writebatch_clear(rocksdb_writebatch_t*);
+extern int rocksdb_writebatch_count(rocksdb_writebatch_t*);
 extern void rocksdb_writebatch_put(
    rocksdb_writebatch_t*,
    const char* key, size_t klen,
    const char* val, size_t vlen);
+extern void rocksdb_writebatch_merge(
+    rocksdb_writebatch_t*,
+    const char* key, size_t klen,
+    const char* val, size_t vlen);
 extern void rocksdb_writebatch_delete(
    rocksdb_writebatch_t*,
    const char* key, size_t klen);
@@ -180,6 +217,7 @@ extern void rocksdb_writebatch_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));
+extern const char* rocksdb_writebatch_data(rocksdb_writebatch_t*, size_t *size);

 /* Options */

@@ -188,6 +226,8 @@ extern void rocksdb_options_destroy(rocksdb_options_t*);
 extern void rocksdb_options_set_comparator(
    rocksdb_options_t*,
    rocksdb_comparator_t*);
+extern void rocksdb_options_set_merge_operator(rocksdb_options_t*,
+                                               rocksdb_mergeoperator_t*);
 extern void rocksdb_options_set_compression_per_level(
  rocksdb_options_t* opt,
  int* level_values,
@@ -203,13 +243,18 @@ extern void rocksdb_options_set_paranoid_checks(
    rocksdb_options_t*, unsigned char);
 extern void rocksdb_options_set_env(rocksdb_options_t*, rocksdb_env_t*);
 extern void rocksdb_options_set_info_log(rocksdb_options_t*, rocksdb_logger_t*);
+extern void rocksdb_options_set_info_log_level(rocksdb_options_t*, int);
 extern void rocksdb_options_set_write_buffer_size(rocksdb_options_t*, size_t);
 extern void rocksdb_options_set_max_open_files(rocksdb_options_t*, int);
 extern void rocksdb_options_set_cache(rocksdb_options_t*, rocksdb_cache_t*);
+extern void rocksdb_options_set_cache_compressed(rocksdb_options_t*, rocksdb_cache_t*);
 extern void rocksdb_options_set_block_size(rocksdb_options_t*, size_t);
 extern void rocksdb_options_set_block_restart_interval(rocksdb_options_t*, int);
 extern void rocksdb_options_set_compression_options(
    rocksdb_options_t*, int, int, int);
+extern void rocksdb_options_set_whole_key_filtering(rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_prefix_extractor(
+    rocksdb_options_t*, rocksdb_slicetransform_t*);
 extern void rocksdb_options_set_num_levels(rocksdb_options_t*, int);
 extern void rocksdb_options_set_level0_file_num_compaction_trigger(
    rocksdb_options_t*, int);
@@ -217,29 +262,130 @@ extern void rocksdb_options_set_level0_slowdown_writes_trigger(
    rocksdb_options_t*, int);
 extern void rocksdb_options_set_level0_stop_writes_trigger(
    rocksdb_options_t*, int);
+extern void rocksdb_options_set_max_mem_compaction_level(
+    rocksdb_options_t*, int);
 extern void rocksdb_options_set_target_file_size_base(
    rocksdb_options_t*, uint64_t);
 extern void rocksdb_options_set_target_file_size_multiplier(
    rocksdb_options_t*, int);
+extern void rocksdb_options_set_max_bytes_for_level_base(
+    rocksdb_options_t*, uint64_t);
+extern void rocksdb_options_set_max_bytes_for_level_multiplier(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_expanded_compaction_factor(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_max_grandparent_overlap_factor(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_max_bytes_for_level_multiplier_additional(
+    rocksdb_options_t*, int* level_values, size_t num_levels);
+extern void rocksdb_options_enable_statistics(rocksdb_options_t*);
+
 extern void rocksdb_options_set_max_write_buffer_number(rocksdb_options_t*, int);
 extern void rocksdb_options_set_min_write_buffer_number_to_merge(rocksdb_options_t*, int);
 extern void rocksdb_options_set_max_background_compactions(rocksdb_options_t*, int);
 extern void rocksdb_options_set_max_background_flushes(rocksdb_options_t*, int);
+extern void rocksdb_options_set_max_log_file_size(rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_log_file_time_to_roll(rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_keep_log_file_num(rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_soft_rate_limit(rocksdb_options_t*, double);
+extern void rocksdb_options_set_hard_rate_limit(rocksdb_options_t*, double);
+extern void rocksdb_options_set_rate_limit_delay_max_milliseconds(
+    rocksdb_options_t*, unsigned int);
+extern void rocksdb_options_set_max_manifest_file_size(
+    rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_no_block_cache(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_table_cache_numshardbits(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_table_cache_remove_scan_count_limit(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_arena_block_size(
+    rocksdb_options_t*, size_t);
 extern void rocksdb_options_set_use_fsync(
    rocksdb_options_t*, int);
+extern void rocksdb_options_set_db_stats_log_interval(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_db_log_dir(
+    rocksdb_options_t*, const char*);
+extern void rocksdb_options_set_wal_dir(
+    rocksdb_options_t*, const char*);
+extern void rocksdb_options_set_WAL_ttl_seconds(
+    rocksdb_options_t*, uint64_t);
+extern void rocksdb_options_set_WAL_size_limit_MB(
+    rocksdb_options_t*, uint64_t);
+extern void rocksdb_options_set_manifest_preallocation_size(
+    rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_purge_redundant_kvs_while_flush(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_allow_os_buffer(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_allow_mmap_reads(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_allow_mmap_writes(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_is_fd_close_on_exec(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_skip_log_error_on_recovery(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_stats_dump_period_sec(
+    rocksdb_options_t*, unsigned int);
+extern void rocksdb_options_set_block_size_deviation(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_advise_random_on_open(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_access_hint_on_compaction_start(
+    rocksdb_options_t*, int);
+extern void rocksdb_options_set_use_adaptive_mutex(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_bytes_per_sync(
+    rocksdb_options_t*, uint64_t);
+extern void rocksdb_options_set_verify_checksums_in_compaction(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_filter_deletes(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_max_sequential_skip_in_iterations(
+    rocksdb_options_t*, uint64_t);
 extern void rocksdb_options_set_disable_data_sync(rocksdb_options_t*, int);
 extern void rocksdb_options_set_disable_auto_compactions(rocksdb_options_t*, int);
 extern void rocksdb_options_set_disable_seek_compaction(rocksdb_options_t*, int);
+extern void rocksdb_options_set_delete_obsolete_files_period_micros(
+    rocksdb_options_t*, uint64_t);
 extern void rocksdb_options_set_source_compaction_factor(rocksdb_options_t*, int);
 extern void rocksdb_options_prepare_for_bulk_load(rocksdb_options_t*);
 extern void rocksdb_options_set_memtable_vector_rep(rocksdb_options_t*);
+extern void rocksdb_options_set_hash_skip_list_rep(rocksdb_options_t*, size_t, int32_t, int32_t);
+extern void rocksdb_options_set_hash_link_list_rep(rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_plain_table_factory(rocksdb_options_t*, uint32_t, int, double, size_t);

+extern void rocksdb_options_set_max_bytes_for_level_base(rocksdb_options_t* opt, uint64_t n);
+extern void rocksdb_options_set_stats_dump_period_sec(rocksdb_options_t* opt, unsigned int sec);
+
+extern void rocksdb_options_set_min_level_to_compress(rocksdb_options_t* opt, int level);
+
+extern void rocksdb_options_set_memtable_prefix_bloom_bits(
+    rocksdb_options_t*, uint32_t);
+extern void rocksdb_options_set_memtable_prefix_bloom_probes(
+    rocksdb_options_t*, uint32_t);
+extern void rocksdb_options_set_max_successive_merges(
+    rocksdb_options_t*, size_t);
+extern void rocksdb_options_set_min_partial_merge_operands(
+    rocksdb_options_t*, uint32_t);
+extern void rocksdb_options_set_bloom_locality(
+    rocksdb_options_t*, uint32_t);
+extern void rocksdb_options_set_allow_thread_local(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_inplace_update_support(
+    rocksdb_options_t*, unsigned char);
+extern void rocksdb_options_set_inplace_update_num_locks(
+    rocksdb_options_t*, size_t);

 enum {
  rocksdb_no_compression = 0,
  rocksdb_snappy_compression = 1,
-  rocksdb_zlib_compression = 1,
-  rocksdb_bz2_compression = 1
+  rocksdb_zlib_compression = 2,
+  rocksdb_bz2_compression = 3,
+  rocksdb_lz4_compression = 4,
+  rocksdb_lz4hc_compression = 5
 };
 extern void rocksdb_options_set_compression(rocksdb_options_t*, int);

@@ -275,12 +421,39 @@ extern rocksdb_filterpolicy_t* rocksdb_filterpolicy_create(
        void*,
        const char* key, size_t length,
        const char* filter, size_t filter_length),
+    void (*delete_filter)(
+        void*,
+        const char* filter, size_t filter_length),
    const char* (*name)(void*));
 extern void rocksdb_filterpolicy_destroy(rocksdb_filterpolicy_t*);

 extern rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom(
    int bits_per_key);

+/* Merge Operator */
+
+extern rocksdb_mergeoperator_t* rocksdb_mergeoperator_create(
+    void* state,
+    void (*destructor)(void*),
+    char* (*full_merge)(
+        void*,
+        const char* key, size_t key_length,
+        const char* existing_value, size_t existing_value_length,
+        const char* const* operands_list, const size_t* operands_list_length,
+        int num_operands,
+        unsigned char* success, size_t* new_value_length),
+    char* (*partial_merge)(
+        void*,
+        const char* key, size_t key_length,
+        const char* const* operands_list, const size_t* operands_list_length,
+        int num_operands,
+        unsigned char* success, size_t* new_value_length),
+    void (*delete_value)(
+        void*,
+        const char* value, size_t value_length),
+    const char* (*name)(void*));
+extern void rocksdb_mergeoperator_destroy(rocksdb_mergeoperator_t*);
+
 /* Read options */

 extern rocksdb_readoptions_t* rocksdb_readoptions_create();
@@ -290,9 +463,17 @@ extern void rocksdb_readoptions_set_verify_checksums(
    unsigned char);
 extern void rocksdb_readoptions_set_fill_cache(
    rocksdb_readoptions_t*, unsigned char);
+extern void rocksdb_readoptions_set_prefix_seek(
+    rocksdb_readoptions_t*, unsigned char);
 extern void rocksdb_readoptions_set_snapshot(
    rocksdb_readoptions_t*,
    const rocksdb_snapshot_t*);
+extern void rocksdb_readoptions_set_prefix(
+    rocksdb_readoptions_t*, const char* key, size_t keylen);
+extern void rocksdb_readoptions_set_read_tier(
+    rocksdb_readoptions_t*, int);
+extern void rocksdb_readoptions_set_tailing(
+    rocksdb_readoptions_t*, unsigned char);

 /* Write options */

@@ -302,6 +483,13 @@ extern void rocksdb_writeoptions_set_sync(
    rocksdb_writeoptions_t*, unsigned char);
 extern void rocksdb_writeoptions_disable_WAL(rocksdb_writeoptions_t* opt, int disable);

+/* Flush options */
+
+extern rocksdb_flushoptions_t* rocksdb_flushoptions_create();
+extern void rocksdb_flushoptions_destroy(rocksdb_flushoptions_t*);
+extern void rocksdb_flushoptions_set_wait(
+    rocksdb_flushoptions_t*, unsigned char);
+
 /* Cache */

 extern rocksdb_cache_t* rocksdb_cache_create_lru(size_t capacity);
@@ -314,6 +502,25 @@ extern void rocksdb_env_set_background_threads(rocksdb_env_t* env, int n);
 extern void rocksdb_env_set_high_priority_background_threads(rocksdb_env_t* env, int n);
 extern void rocksdb_env_destroy(rocksdb_env_t*);

+/* SliceTransform */
+
+extern rocksdb_slicetransform_t* rocksdb_slicetransform_create(
+    void* state,
+    void (*destructor)(void*),
+    char* (*transform)(
+        void*,
+        const char* key, size_t length,
+        size_t* dst_length),
+    unsigned char (*in_domain)(
+        void*,
+        const char* key, size_t length),
+    unsigned char (*in_range)(
+        void*,
+        const char* key, size_t length),
+    const char* (*name)(void*));
+extern rocksdb_slicetransform_t* rocksdb_slicetransform_create_fixed_prefix(size_t);
+extern void rocksdb_slicetransform_destroy(rocksdb_slicetransform_t*);
+
 /* Universal Compaction options */

 enum {
@@ -337,6 +544,28 @@ extern void rocksdb_universal_compaction_options_set_stop_style(
 extern void rocksdb_universal_compaction_options_destroy(
  rocksdb_universal_compaction_options_t*);

+extern int rocksdb_livefiles_count(
+  const rocksdb_livefiles_t*);
+extern const char* rocksdb_livefiles_name(
+  const rocksdb_livefiles_t*,
+  int index);
+extern int rocksdb_livefiles_level(
+  const rocksdb_livefiles_t*,
+  int index);
+extern size_t rocksdb_livefiles_size(
+  const rocksdb_livefiles_t*,
+  int index);
+extern const char* rocksdb_livefiles_smallestkey(
+  const rocksdb_livefiles_t*,
+  int index,
+  size_t* size);
+extern const char* rocksdb_livefiles_largestkey(
+  const rocksdb_livefiles_t*,
+  int index,
+  size_t* size);
+extern void rocksdb_livefiles_destroy(
+  const rocksdb_livefiles_t*);
+
 #ifdef __cplusplus
 }  /* end extern "C" */
 #endif
@@ -102,7 +102,10 @@ class Cache {
  virtual uint64_t NewId() = 0;

  // returns the maximum configured capacity of the cache
-  virtual size_t GetCapacity() = 0;
+  virtual size_t GetCapacity() const = 0;
+
+  // returns the memory size for the entries residing in the cache.
+  virtual size_t GetUsage() const = 0;

  // Call this on shutdown if you want to speed it up. Cache will disown
  // any underlying data and will not free it on delete. This call will leak
@@ -10,21 +10,34 @@
 #define STORAGE_ROCKSDB_INCLUDE_COMPACTION_FILTER_H_

 #include <string>
+#include <vector>

 namespace rocksdb {

 class Slice;
+class SliceTransform;
+
+// Context information of a compaction run
+struct CompactionFilterContext {
+  // Does this compaction run include all data files
+  bool is_full_compaction;
+  // Is this compaction requested by the client (true),
+  // or is it occurring as an automatic compaction process
+  bool is_manual_compaction;
+};

 // CompactionFilter allows an application to modify/delete a key-value at
 // the time of compaction.

 class CompactionFilter {
 public:
-
  // Context information of a compaction run
  struct Context {
    // Does this compaction run include all data files
    bool is_full_compaction;
+    // Is this compaction requested by the client (true),
+    // or is it occurring as an automatic compaction process
+    bool is_manual_compaction;
  };

  virtual ~CompactionFilter() {}
@@ -61,14 +74,47 @@ class CompactionFilter {
  virtual const char* Name() const = 0;
 };

+// CompactionFilterV2 that buffers kv pairs sharing the same prefix and let
+// application layer to make individual decisions for all the kv pairs in the
+// buffer.
+class CompactionFilterV2 {
+ public:
+  virtual ~CompactionFilterV2() {}
+
+  // The compaction process invokes this method for all the kv pairs
+  // sharing the same prefix. It is a "roll-up" version of CompactionFilter.
+  //
+  // Each entry in the return vector indicates if the corresponding kv should
+  // be preserved in the output of this compaction run. The application can
+  // inspect the exisitng values of the keys and make decision based on it.
+  //
+  // When a value is to be preserved, the application has the option
+  // to modify the entry in existing_values and pass it back through an entry
+  // in new_values. A corresponding values_changed entry needs to be set to
+  // true in this case. Note that the new_values vector contains only changed
+  // values, i.e. new_values.size() <= values_changed.size().
+  //
+  typedef std::vector<Slice> SliceVector;
+  virtual std::vector<bool> Filter(int level,
+                                   const SliceVector& keys,
+                                   const SliceVector& existing_values,
+                                   std::vector<std::string>* new_values,
+                                   std::vector<bool>* values_changed)
+    const = 0;
+
+  // Returns a name that identifies this compaction filter.
+  // The name will be printed to LOG file on start up for diagnosis.
+  virtual const char* Name() const = 0;
+};
+
 // Each compaction will create a new CompactionFilter allowing the
 // application to know about different campactions
 class CompactionFilterFactory {
 public:
-  virtual ~CompactionFilterFactory() { };
+  virtual ~CompactionFilterFactory() { }

  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
-    const CompactionFilter::Context& context) = 0;
+      const CompactionFilter::Context& context) = 0;

  // Returns a name that identifies this compaction filter factory.
  virtual const char* Name() const = 0;
@@ -78,8 +124,8 @@ class CompactionFilterFactory {
 // return any filter
 class DefaultCompactionFilterFactory : public CompactionFilterFactory {
 public:
-  virtual std::unique_ptr<CompactionFilter>
-  CreateCompactionFilter(const CompactionFilter::Context& context) override {
+  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
+      const CompactionFilter::Context& context) override {
    return std::unique_ptr<CompactionFilter>(nullptr);
  }

@@ -88,6 +134,65 @@ class DefaultCompactionFilterFactory : public CompactionFilterFactory {
  }
 };

+// Each compaction will create a new CompactionFilterV2
+//
+// CompactionFilterFactoryV2 enables application to specify a prefix and use
+// CompactionFilterV2 to filter kv-pairs in batches. Each batch contains all
+// the kv-pairs sharing the same prefix.
+//
+// This is useful for applications that require grouping kv-pairs in
+// compaction filter to make a purge/no-purge decision. For example, if the
+// key prefix is user id and the rest of key represents the type of value.
+// This batching filter will come in handy if the application's compaction
+// filter requires knowledge of all types of values for any user id.
+//
+class CompactionFilterFactoryV2 {
+ public:
+  // NOTE: CompactionFilterFactoryV2 will not delete prefix_extractor
+  explicit CompactionFilterFactoryV2(const SliceTransform* prefix_extractor)
+    : prefix_extractor_(prefix_extractor) { }
+
+  virtual ~CompactionFilterFactoryV2() { }
+
+  virtual std::unique_ptr<CompactionFilterV2> CreateCompactionFilterV2(
+    const CompactionFilterContext& context) = 0;
+
+  // Returns a name that identifies this compaction filter factory.
+  virtual const char* Name() const = 0;
+
+  const SliceTransform* GetPrefixExtractor() const {
+    return prefix_extractor_;
+  }
+
+  void SetPrefixExtractor(const SliceTransform* prefix_extractor) {
+    prefix_extractor_ = prefix_extractor;
+  }
+
+ private:
+  // Prefix extractor for compaction filter v2
+  // Keys sharing the same prefix will be buffered internally.
+  // Client can implement a Filter callback function to operate on the buffer
+  const SliceTransform* prefix_extractor_;
+};
+
+// Default implementaion of CompactionFilterFactoryV2 which does not
+// return any filter
+class DefaultCompactionFilterFactoryV2 : public CompactionFilterFactoryV2 {
+ public:
+  explicit DefaultCompactionFilterFactoryV2()
+      : CompactionFilterFactoryV2(nullptr) { }
+
+  virtual std::unique_ptr<CompactionFilterV2>
+  CreateCompactionFilterV2(
+      const CompactionFilterContext& context) override {
+    return std::unique_ptr<CompactionFilterV2>(nullptr);
+  }
+
+  virtual const char* Name() const override {
+    return "DefaultCompactionFilterFactoryV2";
+  }
+};
+
 }  // namespace rocksdb

 #endif  // STORAGE_ROCKSDB_INCLUDE_COMPACTION_FILTER_H_
@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <memory>
 #include <vector>
+#include <unordered_map>
 #include "rocksdb/iterator.h"
 #include "rocksdb/options.h"
 #include "rocksdb/types.h"
@@ -30,7 +31,9 @@ struct Options;
 struct ReadOptions;
 struct WriteOptions;
 struct FlushOptions;
+struct TableProperties;
 class WriteBatch;
+class Env;

 // Metadata associated with each SST file.
 struct LiveFileMetaData {
@@ -60,6 +63,12 @@ struct Range {
  Range(const Slice& s, const Slice& l) : start(s), limit(l) { }
 };

+// A collections of table properties objects, where
+//  key: is the table's file name.
+//  value: the table properties object of the given table.
+typedef std::unordered_map<std::string, std::shared_ptr<const TableProperties>>
+    TablePropertiesCollection;
+
 // A DB is a persistent ordered map from keys to values.
 // A DB is safe for concurrent access from multiple threads without
 // any external synchronization.
@@ -260,7 +269,7 @@ class DB {

  // GetLiveFiles followed by GetSortedWalFiles can generate a lossless backup

-  // THIS METHOD IS DEPRECATED. Use the GetTableMetaData to get more
+  // THIS METHOD IS DEPRECATED. Use the GetLiveFilesMetaData to get more
  // detailed information on the live files.
  // Retrieve the list of all files in the database. The files are
  // relative to the dbname and are not absolute paths. The valid size of the
@@ -291,8 +300,10 @@ class DB {
  // use this api, else the WAL files will get
  // cleared aggressively and the iterator might keep getting invalid before
  // an update is read.
-  virtual Status GetUpdatesSince(SequenceNumber seq_number,
-                                 unique_ptr<TransactionLogIterator>* iter) = 0;
+  virtual Status GetUpdatesSince(
+      SequenceNumber seq_number, unique_ptr<TransactionLogIterator>* iter,
+      const TransactionLogIterator::ReadOptions&
+          read_options = TransactionLogIterator::ReadOptions()) = 0;

  // Delete the file name from the db directory and update the internal state to
  // reflect that. Supports deletion of sst and log files only. 'name' must be
@@ -301,15 +312,15 @@ class DB {

  // Returns a list of all table files with their level, start key
  // and end key
-  virtual void GetLiveFilesMetaData(
-    std::vector<LiveFileMetaData> *metadata) {
-  }
+  virtual void GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata) {}

  // Sets the globally unique ID created at database creation time by invoking
  // Env::GenerateUniqueId(), in identity. Returns Status::OK if identity could
  // be set properly
  virtual Status GetDbIdentity(std::string& identity) = 0;

+  virtual Status GetPropertiesOfAllTables(TablePropertiesCollection* props) = 0;
+
 private:
  // No copying allowed
  DB(const DB&);
@@ -59,13 +59,21 @@ struct EnvOptions {
  bool use_mmap_writes = true;

  // If true, set the FD_CLOEXEC on open fd.
-  bool set_fd_cloexec= true;
+  bool set_fd_cloexec = true;

  // Allows OS to incrementally sync files to disk while they are being
  // written, in the background. Issue one request for every bytes_per_sync
  // written. 0 turns it off.
  // Default: 0
  uint64_t bytes_per_sync = 0;
+
+  // If true, we will preallocate the file with FALLOC_FL_KEEP_SIZE flag, which
+  // means that file size won't change as part of preallocation.
+  // If false, preallocation will also change the file size. This option will
+  // improve the performance in workloads where you sync the data on every
+  // write. By default, we set it to true for MANIFEST writes and false for
+  // WAL writes
+  bool fallocate_with_keep_size = true;
 };

 class Env {
@@ -205,6 +213,14 @@ class Env {
  // When "function(arg)" returns, the thread will be destroyed.
  virtual void StartThread(void (*function)(void* arg), void* arg) = 0;

+  // Wait for all threads started by StartThread to terminate.
+  virtual void WaitForJoin() {}
+
+  // Get thread pool queue length for specific thrad pool.
+  virtual unsigned int GetThreadPoolQueueLen(Priority pri = LOW) const {
+    return 0;
+  }
+
  // *path is set to a temporary directory that can be used for testing. It may
  // or many not have just been created. The directory may or may not differ
  // between runs of the same process, but subsequent calls will return the
@@ -250,6 +266,16 @@ class Env {
  // Generates a unique id that can be used to identify a db
  virtual std::string GenerateUniqueId();

+  // OptimizeForLogWrite will create a new EnvOptions object that is a copy of
+  // the EnvOptions in the parameters, but is optimized for writing log files.
+  // Default implementation returns the copy of the same object.
+  virtual EnvOptions OptimizeForLogWrite(const EnvOptions& env_options) const;
+  // OptimizeForManifestWrite will create a new EnvOptions object that is a copy
+  // of the EnvOptions in the parameters, but is optimized for writing manifest
+  // files. Default implementation returns the copy of the same object.
+  virtual EnvOptions OptimizeForManifestWrite(const EnvOptions& env_options)
+      const;
+
 private:
  // No copying allowed
  Env(const Env&);
@@ -508,25 +534,66 @@ class Directory {
  virtual Status Fsync() = 0;
 };

+enum InfoLogLevel : unsigned char {
+  DEBUG = 0,
+  INFO,
+  WARN,
+  ERROR,
+  FATAL,
+  NUM_INFO_LOG_LEVELS,
+};
+
 // An interface for writing log messages.
 class Logger {
 public:
  enum { DO_NOT_SUPPORT_GET_LOG_FILE_SIZE = -1 };
-  Logger() { }
+  explicit Logger(const InfoLogLevel log_level = InfoLogLevel::INFO)
+      : log_level_(log_level) {}
  virtual ~Logger();

  // Write an entry to the log file with the specified format.
  virtual void Logv(const char* format, va_list ap) = 0;
+
+  // Write an entry to the log file with the specified log level
+  // and format.  Any log with level under the internal log level
+  // of *this (see @SetInfoLogLevel and @GetInfoLogLevel) will not be
+  // printed.
+  void Logv(const InfoLogLevel log_level, const char* format, va_list ap) {
+    static const char* kInfoLogLevelNames[5] = {"DEBUG", "INFO", "WARN",
+                                                "ERROR", "FATAL"};
+    if (log_level < log_level_) {
+      return;
+    }
+
+    if (log_level == INFO) {
+      // Doesn't print log level if it is INFO level.
+      // This is to avoid unexpected performance regression after we add
+      // the feature of log level. All the logs before we add the feature
+      // are INFO level. We don't want to add extra costs to those existing
+      // logging.
+      Logv(format, ap);
+    } else {
+      char new_format[500];
+      snprintf(new_format, sizeof(new_format) - 1, "[%s] %s",
+               kInfoLogLevelNames[log_level], format);
+      Logv(new_format, ap);
+    }
+  }
  virtual size_t GetLogFileSize() const {
    return DO_NOT_SUPPORT_GET_LOG_FILE_SIZE;
  }
  // Flush to the OS buffers
  virtual void Flush() {}
+  virtual InfoLogLevel GetInfoLogLevel() const { return log_level_; }
+  virtual void SetInfoLogLevel(const InfoLogLevel log_level) {
+    log_level_ = log_level;
+  }

 private:
  // No copying allowed
  Logger(const Logger&);
  void operator=(const Logger&);
+  InfoLogLevel log_level_;
 };


@@ -541,10 +608,20 @@ class FileLock {
  void operator=(const FileLock&);
 };

-
 extern void LogFlush(const shared_ptr<Logger>& info_log);

+extern void Log(const InfoLogLevel log_level,
+                const shared_ptr<Logger>& info_log, const char* format, ...);
+
+// a set of log functions with different log levels.
+extern void Debug(const shared_ptr<Logger>& info_log, const char* format, ...);
+extern void Info(const shared_ptr<Logger>& info_log, const char* format, ...);
+extern void Warn(const shared_ptr<Logger>& info_log, const char* format, ...);
+extern void Error(const shared_ptr<Logger>& info_log, const char* format, ...);
+extern void Fatal(const shared_ptr<Logger>& info_log, const char* format, ...);
+
 // Log the specified data to *info_log if info_log is non-nullptr.
+// The default info log level is InfoLogLevel::ERROR.
 extern void Log(const shared_ptr<Logger>& info_log, const char* format, ...)
 #   if defined(__GNUC__) || defined(__clang__)
    __attribute__((__format__ (__printf__, 2, 3)))
@@ -553,12 +630,23 @@ extern void Log(const shared_ptr<Logger>& info_log, const char* format, ...)

 extern void LogFlush(Logger *info_log);

+extern void Log(const InfoLogLevel log_level, Logger* info_log,
+                const char* format, ...);
+
+// The default info log level is InfoLogLevel::ERROR.
 extern void Log(Logger* info_log, const char* format, ...)
 #   if defined(__GNUC__) || defined(__clang__)
    __attribute__((__format__ (__printf__, 2, 3)))
 #   endif
    ;

+// a set of log functions with different log levels.
+extern void Debug(Logger* info_log, const char* format, ...);
+extern void Info(Logger* info_log, const char* format, ...);
+extern void Warn(Logger* info_log, const char* format, ...);
+extern void Error(Logger* info_log, const char* format, ...);
+extern void Fatal(Logger* info_log, const char* format, ...);
+
 // A utility routine: write "data" to the named file.
 extern Status WriteStringToFile(Env* env, const Slice& data,
                                const std::string& fname);
@@ -634,6 +722,10 @@ class EnvWrapper : public Env {
  void StartThread(void (*f)(void*), void* a) {
    return target_->StartThread(f, a);
  }
+  void WaitForJoin() { return target_->WaitForJoin(); }
+  virtual unsigned int GetThreadPoolQueueLen(Priority pri = LOW) const {
+    return target_->GetThreadPoolQueueLen(pri);
+  }
  virtual Status GetTestDirectory(std::string* path) {
    return target_->GetTestDirectory(path);
  }
@@ -11,6 +11,7 @@ namespace rocksdb {

 class Slice;
 class BlockBuilder;
+struct Options;

 // FlushBlockPolicy provides a configurable way to determine when to flush a
 // block in the block based tables,
@@ -36,29 +37,22 @@ class FlushBlockPolicyFactory {
  // Callers must delete the result after any database that is using the
  // result has been closed.
  virtual FlushBlockPolicy* NewFlushBlockPolicy(
-      const BlockBuilder& data_block_builder) const = 0;
+      const Options& options, const BlockBuilder& data_block_builder) const = 0;

  virtual ~FlushBlockPolicyFactory() { }
 };

 class FlushBlockBySizePolicyFactory : public FlushBlockPolicyFactory {
 public:
-  FlushBlockBySizePolicyFactory(const uint64_t block_size,
-                                const uint64_t block_size_deviation) :
-      block_size_(block_size),
-      block_size_deviation_(block_size_deviation) {
-  }
+  FlushBlockBySizePolicyFactory() {}

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

  virtual FlushBlockPolicy* NewFlushBlockPolicy(
+      const Options& options,
      const BlockBuilder& data_block_builder) const override;
-
- private:
-  const uint64_t block_size_;
-  const uint64_t block_size_deviation_;
 };

 }  // rocksdb
@@ -21,7 +21,7 @@
 // types built in:
 //  - SkipListRep: This is the default; it is backed by a skip list.
 //  - HashSkipListRep: The memtable rep that is best used for keys that are
-//  structured like "prefix:suffix" where iteration withing a prefix is
+//  structured like "prefix:suffix" where iteration within a prefix is
 //  common and iteration across different prefixes is rare. It is backed by
 //  a hash map where each bucket is a skip list.
 //  - VectorRep: This is backed by an unordered std::vector. On iteration, the
@@ -33,17 +33,20 @@
 // iteration over the entire collection is rare since doing so requires all the
 // keys to be copied into a sorted data structure.

-#ifndef STORAGE_ROCKSDB_DB_MEMTABLEREP_H_
-#define STORAGE_ROCKSDB_DB_MEMTABLEREP_H_
+#pragma once

 #include <memory>
+#include <stdint.h>

 namespace rocksdb {

 class Arena;
+class LookupKey;
 class Slice;
 class SliceTransform;

+typedef void* KeyHandle;
+
 class MemTableRep {
 public:
  // KeyComparator provides a means to compare keys, which are internal keys
@@ -52,16 +55,28 @@ class MemTableRep {
   public:
    // Compare a and b. Return a negative value if a is less than b, 0 if they
    // are equal, and a positive value if a is greater than b
-    virtual int operator()(const char* a, const char* b) const = 0;
+    virtual int operator()(const char* prefix_len_key1,
+                           const char* prefix_len_key2) const = 0;
+
+    virtual int operator()(const char* prefix_len_key,
+                           const Slice& key) const = 0;

    virtual ~KeyComparator() { }
  };

+  explicit MemTableRep(Arena* arena) : arena_(arena) {}
+
+  // Allocate a buf of len size for storing key. The idea is that a specific
+  // memtable representation knows its underlying data structure better. By
+  // allowing it to allocate memory, it can possibly put correlated stuff
+  // in consecutive memory area to make processor prefetching more efficient.
+  virtual KeyHandle Allocate(const size_t len, char** buf);
+
  // Insert key into the collection. (The caller will pack key and value into a
-  // single buffer and pass that in as the parameter to Insert)
+  // single buffer and pass that in as the parameter to Insert).
  // REQUIRES: nothing that compares equal to key is currently in the
  // collection.
-  virtual void Insert(const char* key) = 0;
+  virtual void Insert(KeyHandle handle) = 0;

  // Returns true iff an entry that compares equal to key is in the collection.
  virtual bool Contains(const char* key) const = 0;
@@ -70,6 +85,20 @@ class MemTableRep {
  // nothing.
  virtual void MarkReadOnly() { }

+  // Look up key from the mem table, since the first key in the mem table whose
+  // user_key matches the one given k, call the function callback_func(), with
+  // callback_args directly forwarded as the first parameter, and the mem table
+  // key as the second parameter. If the return value is false, then terminates.
+  // Otherwise, go through the next key.
+  // It's safe for Get() to terminate after having finished all the potential
+  // key for the k.user_key(), or not.
+  //
+  // Default:
+  // Get() function with a default value of dynamically construct an iterator,
+  // seek and call the call back function.
+  virtual void Get(const LookupKey& k, void* callback_args,
+                   bool (*callback_func)(void* arg, const char* entry));
+
  // Report an approximation of how much memory has been used other than memory
  // that was allocated through the arena.
  virtual size_t ApproximateMemoryUsage() = 0;
@@ -82,7 +111,7 @@ class MemTableRep {
    // Initialize an iterator over the specified collection.
    // The returned iterator is not valid.
    // explicit Iterator(const MemTableRep* collection);
-    virtual ~Iterator() { };
+    virtual ~Iterator() {}

    // Returns true iff the iterator is positioned at a valid node.
    virtual bool Valid() const = 0;
@@ -100,7 +129,7 @@ class MemTableRep {
    virtual void Prev() = 0;

    // Advance to the first entry with a key >= target
-    virtual void Seek(const char* target) = 0;
+    virtual void Seek(const Slice& internal_key, const char* memtable_key) = 0;

    // Position at the first entry in collection.
    // Final state of iterator is Valid() iff collection is not empty.
@@ -134,15 +163,17 @@ class MemTableRep {
  // When *key is an internal key concatenated with the value, returns the
  // user key.
  virtual Slice UserKey(const char* key) const;
+
+  Arena* arena_;
 };

 // This is the base class for all factories that are used by RocksDB to create
 // new MemTableRep objects
 class MemTableRepFactory {
 public:
-  virtual ~MemTableRepFactory() { };
-  virtual MemTableRep* CreateMemTableRep(MemTableRep::KeyComparator&,
-                                         Arena*) = 0;
+  virtual ~MemTableRepFactory() {}
+  virtual MemTableRep* CreateMemTableRep(const MemTableRep::KeyComparator&,
+      Arena*, const SliceTransform*) = 0;
  virtual const char* Name() const = 0;
 };

@@ -156,10 +187,12 @@ class MemTableRepFactory {
 //     bytes reserved for usage.
 class VectorRepFactory : public MemTableRepFactory {
  const size_t count_;
-public:
+
+ public:
  explicit VectorRepFactory(size_t count = 0) : count_(count) { }
-  virtual MemTableRep* CreateMemTableRep(MemTableRep::KeyComparator&,
-                                         Arena*) override;
+  virtual MemTableRep* CreateMemTableRep(
+      const MemTableRep::KeyComparator&, Arena*,
+      const SliceTransform*) override;
  virtual const char* Name() const override {
    return "VectorRepFactory";
  }
@@ -167,34 +200,31 @@ public:

 // This uses a skip list to store keys. It is the default.
 class SkipListFactory : public MemTableRepFactory {
-public:
- virtual MemTableRep* CreateMemTableRep(MemTableRep::KeyComparator&,
-                                        Arena*) override;
+ public:
+  virtual MemTableRep* CreateMemTableRep(
+      const MemTableRep::KeyComparator&, Arena*,
+      const SliceTransform*) override;
  virtual const char* Name() const override {
    return "SkipListFactory";
  }
 };

-// HashSkipListRep is backed by hash map of buckets. Each bucket is a skip
-// list. All the keys with the same prefix will be in the same bucket.
-// The prefix is determined using user supplied SliceTransform. It has
-// to match prefix_extractor in options.prefix_extractor.
-//
-// Iteration over the entire collection is implemented by dumping all the keys
-// into a separate skip list. Thus, these data structures are best used when
-// iteration over the entire collection is rare.
-//
-// Parameters:
-//   transform: The prefix extractor that returns prefix when supplied a user
-//     key. Has to match options.prefix_extractor
-//   bucket_count: Number of buckets in a hash_map. Each bucket needs
-//     8 bytes. By default, we set buckets to one million, which
-//     will take 8MB of memory. If you know the number of keys you'll
-//     keep in hash map, set bucket count to be approximately twice
-//     the number of keys
+// This class contains a fixed array of buckets, each
+// pointing to a skiplist (null if the bucket is empty).
+// bucket_count: number of fixed array buckets
+// skiplist_height: the max height of the skiplist
+// skiplist_branching_factor: probabilistic size ratio between adjacent
+//                            link lists in the skiplist
 extern MemTableRepFactory* NewHashSkipListRepFactory(
-    const SliceTransform* transform, size_t bucket_count = 1000000);
+    size_t bucket_count = 1000000, int32_t skiplist_height = 4,
+    int32_t skiplist_branching_factor = 4
+);

-}
+// The factory is to create memtables with a hashed linked list:
+// it contains a fixed array of buckets, each pointing to a sorted single
+// linked list (null if the bucket is empty).
+// bucket_count: number of fixed array buckets
+extern MemTableRepFactory* NewHashLinkListRepFactory(
+    size_t bucket_count = 50000);

-#endif // STORAGE_ROCKSDB_DB_MEMTABLEREP_H_
+}  // namespace rocksdb
@@ -32,9 +32,9 @@ class Logger;
 //
 //  b) MergeOperator - the generic class for all the more abstract / complex
 //    operations; one method (FullMerge) to merge a Put/Delete value with a
-//    merge operand; and another method (PartialMerge) that merges two
-//    operands together. this is especially useful if your key values have a
-//    complex structure but you would still like to support client-specific
+//    merge operand; and another method (PartialMerge) that merges multiple
+//    operands together. this is especially useful if your key values have
+//    complex structures but you would still like to support client-specific
 //    incremental updates.
 //
 // AssociativeMergeOperator is simpler to implement. MergeOperator is simply
@@ -80,6 +80,13 @@ class MergeOperator {
  // DB::Merge(key, *new_value) would yield the same result as a call
  // to DB::Merge(key, left_op) followed by DB::Merge(key, right_op).
  //
+  // The default implementation of PartialMergeMulti will use this function
+  // as a helper, for backward compatibility.  Any successor class of
+  // MergeOperator should either implement PartialMerge or PartialMergeMulti,
+  // although implementing PartialMergeMulti is suggested as it is in general
+  // more effective to merge multiple operands at a time instead of two
+  // operands at a time.
+  //
  // If it is impossible or infeasible to combine the two operations,
  // leave new_value unchanged and return false. The library will
  // internally keep track of the operations, and apply them in the
@@ -89,12 +96,38 @@ class MergeOperator {
  // and simply "return false". For now, the client should simply return
  // false in any case it cannot perform partial-merge, regardless of reason.
  // If there is corruption in the data, handle it in the FullMerge() function,
-  // and return false there.
-  virtual bool PartialMerge(const Slice& key,
-                            const Slice& left_operand,
-                            const Slice& right_operand,
-                            std::string* new_value,
-                            Logger* logger) const = 0;
+  // and return false there.  The default implementation of PartialMerge will
+  // always return false.
+  virtual bool PartialMerge(const Slice& key, const Slice& left_operand,
+                            const Slice& right_operand, std::string* new_value,
+                            Logger* logger) const {
+    return false;
+  }
+
+  // This function performs merge when all the operands are themselves merge
+  // operation types that you would have passed to a DB::Merge() call in the
+  // same order (front() first)
+  // (i.e. DB::Merge(key, operand_list[0]), followed by
+  //  DB::Merge(key, operand_list[1]), ...)
+  //
+  // PartialMergeMulti should combine them into a single merge operation that is
+  // saved into *new_value, and then it should return true.  *new_value should
+  // be constructed such that a call to DB::Merge(key, *new_value) would yield
+  // the same result as subquential individual calls to DB::Merge(key, operand)
+  // for each operand in operand_list from front() to back().
+  //
+  // The PartialMergeMulti function will be called only when the list of
+  // operands are long enough. The minimum amount of operands that will be
+  // passed to the function are specified by the "min_partial_merge_operands"
+  // option.
+  //
+  // In the default implementation, PartialMergeMulti will invoke PartialMerge
+  // multiple times, where each time it only merges two operands.  Developers
+  // should either implement PartialMergeMulti, or implement PartialMerge which
+  // is served as the helper function of the default PartialMergeMulti.
+  virtual bool PartialMergeMulti(const Slice& key,
+                                 const std::deque<Slice>& operand_list,
+                                 std::string* new_value, Logger* logger) const;

  // The name of the MergeOperator. Used to check for MergeOperator
  // mismatches (i.e., a DB created with one MergeOperator is
@@ -22,8 +22,10 @@ namespace rocksdb {
 class Cache;
 class CompactionFilter;
 class CompactionFilterFactory;
+class CompactionFilterFactoryV2;
 class Comparator;
 class Env;
+enum InfoLogLevel : unsigned char;
 class FilterPolicy;
 class Logger;
 class MergeOperator;
@@ -34,6 +36,7 @@ class TablePropertiesCollector;
 class Slice;
 class SliceTransform;
 class Statistics;
+class InternalKeyComparator;

 using std::shared_ptr;

@@ -44,10 +47,8 @@ using std::shared_ptr;
 enum CompressionType : char {
  // NOTE: do not change the values of existing entries, as these are
  // part of the persistent format on disk.
-  kNoCompression = 0x0,
-  kSnappyCompression = 0x1,
-  kZlibCompression = 0x2,
-  kBZip2Compression = 0x3
+  kNoCompression = 0x0, kSnappyCompression = 0x1, kZlibCompression = 0x2,
+  kBZip2Compression = 0x3, kLZ4Compression = 0x4, kLZ4HCCompression = 0x5
 };

 enum CompactionStyle : char {
@@ -65,6 +66,12 @@ struct CompressionOptions {
      : window_bits(wbits), level(lev), strategy(strategy) {}
 };

+enum UpdateStatus {    // Return status For inplace update callback
+  UPDATE_FAILED   = 0, // Nothing to update
+  UPDATED_INPLACE = 1, // Value updated inplace
+  UPDATED         = 2, // No inplace update. Merged value set
+};
+
 // Options to control the behavior of a database (passed to DB::Open)
 struct Options {
  // -------------------
@@ -117,6 +124,12 @@ struct Options {
  // Default: a factory that doesn't provide any object
  std::shared_ptr<CompactionFilterFactory> compaction_filter_factory;

+  // Version TWO of the compaction_filter_factory
+  // It supports rolling compaction
+  //
+  // Default: a factory that doesn't provide any object
+  std::shared_ptr<CompactionFilterFactoryV2> compaction_filter_factory_v2;
+
  // If true, the database will be created if it is missing.
  // Default: false
  bool create_if_missing;
@@ -130,10 +143,10 @@ struct Options {
  // errors.  This may have unforeseen ramifications: for example, a
  // corruption of one DB entry may cause a large number of entries to
  // become unreadable or for the entire DB to become unopenable.
-  // If any of the  writes to the database fails (Put, Delete, Merge, Write),
+  // If any of the writes to the database fails (Put, Delete, Merge, Write),
  // the database will switch to read-only mode and fail all other
  // Write operations.
-  // Default: false
+  // Default: true
  bool paranoid_checks;

  // Use the specified object to interact with the environment,
@@ -147,6 +160,8 @@ struct Options {
  // Default: nullptr
  shared_ptr<Logger> info_log;

+  InfoLogLevel info_log_level;
+
  // -------------------
  // Parameters that affect performance

@@ -179,10 +194,12 @@ struct Options {
  int min_write_buffer_number_to_merge;

  // Number of open files that can be used by the DB.  You may need to
-  // increase this if your database has a large working set (budget
-  // one open file per 2MB of working set).
+  // increase this if your database has a large working set. Value -1 means
+  // files opened are always kept open. You can estimate number of files based
+  // on target_file_size_base and target_file_size_multiplier for level-based
+  // compaction. For universal-style compaction, you can usually set it to -1.
  //
-  // Default: 1000
+  // Default: 5000
  int max_open_files;

  // Control over blocks (user data is stored in a set of blocks, and
@@ -267,7 +284,7 @@ struct Options {
  // 4) prefix(prefix(key)) == prefix(key)
  //
  // Default: nullptr
-  const SliceTransform* prefix_extractor;
+  std::shared_ptr<const SliceTransform> prefix_extractor;

  // If true, place whole keys in the filter (not just prefixes).
  // This must generally be true for gets to be efficient.
@@ -419,7 +436,7 @@ struct Options {
  // Without a separate pool, long running major compaction jobs could
  // potentially block memtable flush jobs of other db instances, leading to
  // unnecessary Put stalls.
-  // Default: 0
+  // Default: 1
  int max_background_flushes;

  // Specify the maximal size of the info log file. If the log file
@@ -545,7 +562,7 @@ struct Options {
  // Allow the OS to mmap file for reading sst tables. Default: false
  bool allow_mmap_reads;

-  // Allow the OS to mmap file for writing. Default: true
+  // Allow the OS to mmap file for writing. Default: false
  bool allow_mmap_writes;

  // Disable child process inherit open files. Default: true
@@ -602,6 +619,11 @@ struct Options {
  // The options needed to support Universal Style compactions
  CompactionOptionsUniversal compaction_options_universal;

+  // If true, compaction will verify checksum on every read that happens
+  // as part of compaction
+  // Default: true
+  bool verify_checksums_in_compaction;
+
  // Use KeyMayExist API to filter deletes when this is true.
  // If KeyMayExist returns false, i.e. the key definitely does not exist, then
  // the delete is a noop. KeyMayExist only incurs in-memory look up.
@@ -630,13 +652,17 @@ struct Options {
  // the tables.
  // Default: emtpy vector -- no user-defined statistics collection will be
  // performed.
-  std::vector<std::shared_ptr<TablePropertiesCollector>>
-  table_properties_collectors;
+  typedef std::vector<std::shared_ptr<TablePropertiesCollector>>
+          TablePropertiesCollectors;
+  TablePropertiesCollectors table_properties_collectors;

-  // Allows thread-safe inplace updates. Requires Updates iff
-  // * key exists in current memtable
-  // * new sizeof(new_value) <= sizeof(old_value)
-  // * old_value for that key is a put i.e. kTypeValue
+  // Allows thread-safe inplace updates.
+  // If inplace_callback function is not set,
+  //   Put(key, new_value) will update inplace the existing_value iff
+  //   * key exists in current memtable
+  //   * new sizeof(new_value) <= sizeof(existing_value)
+  //   * existing_value for that key is a put i.e. kTypeValue
+  // If inplace_callback function is set, check doc for inplace_callback.
  // Default: false.
  bool inplace_update_support;

@@ -644,6 +670,66 @@ struct Options {
  // Default: 10000, if inplace_update_support = true, else 0.
  size_t inplace_update_num_locks;

+  // existing_value - pointer to previous value (from both memtable and sst).
+  //                  nullptr if key doesn't exist
+  // existing_value_size - pointer to size of existing_value).
+  //                       nullptr if key doesn't exist
+  // delta_value - Delta value to be merged with the existing_value.
+  //               Stored in transaction logs.
+  // merged_value - Set when delta is applied on the previous value.
+
+  // Applicable only when inplace_update_support is true,
+  // this callback function is called at the time of updating the memtable
+  // as part of a Put operation, lets say Put(key, delta_value). It allows the
+  // 'delta_value' specified as part of the Put operation to be merged with
+  // an 'existing_value' of the key in the database.
+
+  // If the merged value is smaller in size that the 'existing_value',
+  // then this function can update the 'existing_value' buffer inplace and
+  // the corresponding 'existing_value'_size pointer, if it wishes to.
+  // The callback should return UpdateStatus::UPDATED_INPLACE.
+  // In this case. (In this case, the snapshot-semantics of the rocksdb
+  // Iterator is not atomic anymore).
+
+  // If the merged value is larger in size than the 'existing_value' or the
+  // application does not wish to modify the 'existing_value' buffer inplace,
+  // then the merged value should be returned via *merge_value. It is set by
+  // merging the 'existing_value' and the Put 'delta_value'. The callback should
+  // return UpdateStatus::UPDATED in this case. This merged value will be added
+  // to the memtable.
+
+  // If merging fails or the application does not wish to take any action,
+  // then the callback should return UpdateStatus::UPDATE_FAILED.
+
+  // Please remember that the original call from the application is Put(key,
+  // delta_value). So the transaction log (if enabled) will still contain (key,
+  // delta_value). The 'merged_value' is not stored in the transaction log.
+  // Hence the inplace_callback function should be consistent across db reopens.
+
+  // Default: nullptr
+  UpdateStatus (*inplace_callback)(char* existing_value,
+                                   uint32_t* existing_value_size,
+                                   Slice delta_value,
+                                   std::string* merged_value);
+
+  // if prefix_extractor is set and bloom_bits is not 0, create prefix bloom
+  // for memtable
+  uint32_t memtable_prefix_bloom_bits;
+
+  // number of hash probes per key
+  uint32_t memtable_prefix_bloom_probes;
+
+  // Control locality of bloom filter probes to improve cache miss rate.
+  // This option only applies to memtable prefix bloom and plaintable
+  // prefix bloom. It essentially limits the max number of cache lines each
+  // bloom filter check can touch.
+  // This optimization is turned off when set to 0. The number should never
+  // be greater than number of probes. This option can boost performance
+  // for in-memory workload but should use with care since it can cause
+  // higher false positive rate.
+  // Default: 0
+  uint32_t bloom_locality;
+
  // Maximum number of successive merge operations on a key in the memtable.
  //
  // When a merge operation is added to the memtable and the maximum number of
@@ -654,6 +740,19 @@ struct Options {
  //
  // Default: 0 (disabled)
  size_t max_successive_merges;
+
+  // The number of partial merge operands to accumulate before partial
+  // merge will be performed. Partial merge will not be called
+  // if the list of values to merge is less than min_partial_merge_operands.
+  //
+  // If min_partial_merge_operands < 2, then it will be treated as 2.
+  //
+  // Default: 2
+  uint32_t min_partial_merge_operands;
+
+  // Allow RocksDB to use thread local storage to optimize performance.
+  // Default: true
+  bool allow_thread_local;
 };

 //
@@ -672,7 +771,7 @@ enum ReadTier {
 struct ReadOptions {
  // If true, all data read from underlying storage will be
  // verified against corresponding checksums.
-  // Default: false
+  // Default: true
  bool verify_checksums;

  // Should the "data block"/"index block"/"filter block" read for this
@@ -713,11 +812,13 @@ struct ReadOptions {

  // Specify to create a tailing iterator -- a special iterator that has a
  // view of the complete database (i.e. it can also be used to read newly
-  // added data) and is optimized for sequential reads.
+  // added data) and is optimized for sequential reads. It will return records
+  // that were inserted into the database after the creation of the iterator.
+  // Default: false
  bool tailing;

  ReadOptions()
-      : verify_checksums(false),
+      : verify_checksums(true),
        fill_cache(true),
        prefix_seek(false),
        snapshot(nullptr),
@@ -7,6 +7,7 @@
 #define STORAGE_ROCKSDB_INCLUDE_PERF_CONTEXT_H

 #include <stdint.h>
+#include <string>

 namespace rocksdb {

@@ -26,6 +27,8 @@ struct PerfContext {

  void Reset(); // reset all performance counters to zero

+  std::string ToString() const;
+
  uint64_t user_key_comparison_count; // total number of user key comparisons
  uint64_t block_cache_hit_count;     // total number of block cache hits
  uint64_t block_read_count;          // total number of block reads (with IO)
@@ -38,10 +41,34 @@ struct PerfContext {
  uint64_t internal_key_skipped_count;
  // total number of deletes skipped over during iteration
  uint64_t internal_delete_skipped_count;
-  uint64_t wal_write_time;            // total time spent on writing to WAL
+
+  uint64_t get_snapshot_time;          // total time spent on getting snapshot
+  uint64_t get_from_memtable_time;     // total time spent on querying memtables
+  uint64_t get_from_memtable_count;    // number of mem tables queried
+  // total time spent after Get() finds a key
+  uint64_t get_post_process_time;
+  uint64_t get_from_output_files_time; // total time reading from output files
+  // total time spent on seeking child iters
+  uint64_t seek_child_seek_time;
+  // number of seek issued in child iterators
+  uint64_t seek_child_seek_count;
+  uint64_t seek_min_heap_time;         // total time spent on the merge heap
+  // total time spent on seeking the internal entries
+  uint64_t seek_internal_seek_time;
+  // total time spent on iterating internal entries to find the next user entry
+  uint64_t find_next_user_entry_time;
+  // total time spent on pre or post processing when writing a record
+  uint64_t write_pre_and_post_process_time;
+  uint64_t write_wal_time;            // total time spent on writing to WAL
+  // total time spent on writing to mem tables
+  uint64_t write_memtable_time;
 };

+#if defined(IOS_CROSS_COMPILE)
+extern PerfContext perf_context;
+#else
 extern __thread PerfContext perf_context;
+#endif

 }

@@ -7,7 +7,6 @@
 #define STORAGE_ROCKSDB_INCLUDE_STATISTICS_H_

 #include <atomic>
-#include <cassert>
 #include <cstddef>
 #include <cstdint>
 #include <string>
@@ -18,10 +17,8 @@ namespace rocksdb {

 /**
 * Keep adding ticker's here.
- * Any ticker should have a value less than TICKER_ENUM_MAX.
- * Add a new ticker by assigning it the current value of TICKER_ENUM_MAX
- * Add a string representation in TickersNameMap below.
- * And incrementing TICKER_ENUM_MAX.
+ *  1. Any ticker should be added before TICKER_ENUM_MAX.
+ *  2. Add a readable string in TickersNameMap below for the newly added ticker.
 */
 enum Tickers {
  // total block cache misses
@@ -60,9 +57,9 @@ enum Tickers {
   * COMPACTION_KEY_DROP_* count the reasons for key drop during compaction
   * There are 3 reasons currently.
   */
-  COMPACTION_KEY_DROP_NEWER_ENTRY, // key was written with a newer value.
-  COMPACTION_KEY_DROP_OBSOLETE, // The key is obsolete.
-  COMPACTION_KEY_DROP_USER, // user compaction function has dropped the key.
+  COMPACTION_KEY_DROP_NEWER_ENTRY,  // key was written with a newer value.
+  COMPACTION_KEY_DROP_OBSOLETE,     // The key is obsolete.
+  COMPACTION_KEY_DROP_USER,  // user compaction function has dropped the key.

  // Number of keys written to the database via the Put and Write call's
  NUMBER_KEYS_WRITTEN,
@@ -83,8 +80,7 @@ enum Tickers {
  // write throttle because of too many files in L0
  STALL_L0_NUM_FILES_MICROS,
  RATE_LIMIT_DELAY_MILLIS,
-
-  NO_ITERATORS, // number of iterators currently open
+  NO_ITERATORS,  // number of iterators currently open

  // Number of MultiGet calls, keys read, and bytes read
  NUMBER_MULTIGET_CALLS,
@@ -110,76 +106,83 @@ enum Tickers {
  // Record the number of calls to GetUpadtesSince. Useful to keep track of
  // transaction log iterator refreshes
  GET_UPDATES_SINCE_CALLS,
-
-  BLOCK_CACHE_COMPRESSED_MISS, // miss in the compressed block cache
-  BLOCK_CACHE_COMPRESSED_HIT,  // hit in the compressed block cache
-
-  WAL_FILE_SYNCED,  // Number of times WAL sync is done
-  WAL_FILE_BYTES,   // Number of bytes written to WAL
+  BLOCK_CACHE_COMPRESSED_MISS,  // miss in the compressed block cache
+  BLOCK_CACHE_COMPRESSED_HIT,   // hit in the compressed block cache
+  WAL_FILE_SYNCED,              // Number of times WAL sync is done
+  WAL_FILE_BYTES,               // Number of bytes written to WAL

  // Writes can be processed by requesting thread or by the thread at the
  // head of the writers queue.
  WRITE_DONE_BY_SELF,
  WRITE_DONE_BY_OTHER,
+  WRITE_WITH_WAL,       // Number of Write calls that request WAL
+  COMPACT_READ_BYTES,   // Bytes read during compaction
+  COMPACT_WRITE_BYTES,  // Bytes written during compaction

-  WRITE_WITH_WAL,      // Number of Write calls that request WAL
-
-  COMPACT_READ_BYTES,  // Bytes read during compaction
-  COMPACT_WRITE_BYTES, // Bytes written during compaction
-
+  // Number of table's properties loaded directly from file, without creating
+  // table reader object.
+  NUMBER_DIRECT_LOAD_TABLE_PROPERTIES,
+  NUMBER_SUPERVERSION_ACQUIRES,
+  NUMBER_SUPERVERSION_RELEASES,
+  NUMBER_SUPERVERSION_CLEANUPS,
  TICKER_ENUM_MAX
 };

 // The order of items listed in  Tickers should be the same as
 // the order listed in TickersNameMap
 const std::vector<std::pair<Tickers, std::string>> TickersNameMap = {
-  { BLOCK_CACHE_MISS, "rocksdb.block.cache.miss" },
-  { BLOCK_CACHE_HIT, "rocksdb.block.cache.hit" },
-  { BLOCK_CACHE_ADD, "rocksdb.block.cache.add" },
-  { BLOCK_CACHE_INDEX_MISS, "rocksdb.block.cache.index.miss" },
-  { BLOCK_CACHE_INDEX_HIT, "rocksdb.block.cache.index.hit" },
-  { BLOCK_CACHE_FILTER_MISS, "rocksdb.block.cache.filter.miss" },
-  { BLOCK_CACHE_FILTER_HIT, "rocksdb.block.cache.filter.hit" },
-  { BLOCK_CACHE_DATA_MISS, "rocksdb.block.cache.data.miss" },
-  { BLOCK_CACHE_DATA_HIT, "rocksdb.block.cache.data.hit" },
-  { BLOOM_FILTER_USEFUL, "rocksdb.bloom.filter.useful" },
-  { MEMTABLE_HIT, "rocksdb.memtable.hit" },
-  { MEMTABLE_MISS, "rocksdb.memtable.miss" },
-  { COMPACTION_KEY_DROP_NEWER_ENTRY, "rocksdb.compaction.key.drop.new" },
-  { COMPACTION_KEY_DROP_OBSOLETE, "rocksdb.compaction.key.drop.obsolete" },
-  { COMPACTION_KEY_DROP_USER, "rocksdb.compaction.key.drop.user" },
-  { NUMBER_KEYS_WRITTEN, "rocksdb.number.keys.written" },
-  { NUMBER_KEYS_READ, "rocksdb.number.keys.read" },
-  { NUMBER_KEYS_UPDATED, "rocksdb.number.keys.updated" },
-  { BYTES_WRITTEN, "rocksdb.bytes.written" },
-  { BYTES_READ, "rocksdb.bytes.read" },
-  { NO_FILE_CLOSES, "rocksdb.no.file.closes" },
-  { NO_FILE_OPENS, "rocksdb.no.file.opens" },
-  { NO_FILE_ERRORS, "rocksdb.no.file.errors" },
-  { STALL_L0_SLOWDOWN_MICROS, "rocksdb.l0.slowdown.micros" },
-  { STALL_MEMTABLE_COMPACTION_MICROS, "rocksdb.memtable.compaction.micros" },
-  { STALL_L0_NUM_FILES_MICROS, "rocksdb.l0.num.files.stall.micros" },
-  { RATE_LIMIT_DELAY_MILLIS, "rocksdb.rate.limit.delay.millis" },
-  { NO_ITERATORS, "rocksdb.num.iterators" },
-  { NUMBER_MULTIGET_CALLS, "rocksdb.number.multiget.get" },
-  { NUMBER_MULTIGET_KEYS_READ, "rocksdb.number.multiget.keys.read" },
-  { NUMBER_MULTIGET_BYTES_READ, "rocksdb.number.multiget.bytes.read" },
-  { NUMBER_FILTERED_DELETES, "rocksdb.number.deletes.filtered" },
-  { NUMBER_MERGE_FAILURES, "rocksdb.number.merge.failures" },
-  { SEQUENCE_NUMBER, "rocksdb.sequence.number" },
-  { BLOOM_FILTER_PREFIX_CHECKED, "rocksdb.bloom.filter.prefix.checked" },
-  { BLOOM_FILTER_PREFIX_USEFUL, "rocksdb.bloom.filter.prefix.useful" },
-  { NUMBER_OF_RESEEKS_IN_ITERATION, "rocksdb.number.reseeks.iteration" },
-  { GET_UPDATES_SINCE_CALLS, "rocksdb.getupdatessince.calls" },
-  { BLOCK_CACHE_COMPRESSED_MISS, "rocksdb.block.cachecompressed.miss" },
-  { BLOCK_CACHE_COMPRESSED_HIT, "rocksdb.block.cachecompressed.hit" },
-  { WAL_FILE_SYNCED, "rocksdb.wal.synced" },
-  { WAL_FILE_BYTES, "rocksdb.wal.bytes" },
-  { WRITE_DONE_BY_SELF, "rocksdb.write.self" },
-  { WRITE_DONE_BY_OTHER, "rocksdb.write.other" },
-  { WRITE_WITH_WAL, "rocksdb.write.wal" },
-  { COMPACT_READ_BYTES, "rocksdb.compact.read.bytes" },
-  { COMPACT_WRITE_BYTES, "rocksdb.compact.write.bytes" },
+    {BLOCK_CACHE_MISS, "rocksdb.block.cache.miss"},
+    {BLOCK_CACHE_HIT, "rocksdb.block.cache.hit"},
+    {BLOCK_CACHE_ADD, "rocksdb.block.cache.add"},
+    {BLOCK_CACHE_INDEX_MISS, "rocksdb.block.cache.index.miss"},
+    {BLOCK_CACHE_INDEX_HIT, "rocksdb.block.cache.index.hit"},
+    {BLOCK_CACHE_FILTER_MISS, "rocksdb.block.cache.filter.miss"},
+    {BLOCK_CACHE_FILTER_HIT, "rocksdb.block.cache.filter.hit"},
+    {BLOCK_CACHE_DATA_MISS, "rocksdb.block.cache.data.miss"},
+    {BLOCK_CACHE_DATA_HIT, "rocksdb.block.cache.data.hit"},
+    {BLOOM_FILTER_USEFUL, "rocksdb.bloom.filter.useful"},
+    {MEMTABLE_HIT, "rocksdb.memtable.hit"},
+    {MEMTABLE_MISS, "rocksdb.memtable.miss"},
+    {COMPACTION_KEY_DROP_NEWER_ENTRY, "rocksdb.compaction.key.drop.new"},
+    {COMPACTION_KEY_DROP_OBSOLETE, "rocksdb.compaction.key.drop.obsolete"},
+    {COMPACTION_KEY_DROP_USER, "rocksdb.compaction.key.drop.user"},
+    {NUMBER_KEYS_WRITTEN, "rocksdb.number.keys.written"},
+    {NUMBER_KEYS_READ, "rocksdb.number.keys.read"},
+    {NUMBER_KEYS_UPDATED, "rocksdb.number.keys.updated"},
+    {BYTES_WRITTEN, "rocksdb.bytes.written"},
+    {BYTES_READ, "rocksdb.bytes.read"},
+    {NO_FILE_CLOSES, "rocksdb.no.file.closes"},
+    {NO_FILE_OPENS, "rocksdb.no.file.opens"},
+    {NO_FILE_ERRORS, "rocksdb.no.file.errors"},
+    {STALL_L0_SLOWDOWN_MICROS, "rocksdb.l0.slowdown.micros"},
+    {STALL_MEMTABLE_COMPACTION_MICROS, "rocksdb.memtable.compaction.micros"},
+    {STALL_L0_NUM_FILES_MICROS, "rocksdb.l0.num.files.stall.micros"},
+    {RATE_LIMIT_DELAY_MILLIS, "rocksdb.rate.limit.delay.millis"},
+    {NO_ITERATORS, "rocksdb.num.iterators"},
+    {NUMBER_MULTIGET_CALLS, "rocksdb.number.multiget.get"},
+    {NUMBER_MULTIGET_KEYS_READ, "rocksdb.number.multiget.keys.read"},
+    {NUMBER_MULTIGET_BYTES_READ, "rocksdb.number.multiget.bytes.read"},
+    {NUMBER_FILTERED_DELETES, "rocksdb.number.deletes.filtered"},
+    {NUMBER_MERGE_FAILURES, "rocksdb.number.merge.failures"},
+    {SEQUENCE_NUMBER, "rocksdb.sequence.number"},
+    {BLOOM_FILTER_PREFIX_CHECKED, "rocksdb.bloom.filter.prefix.checked"},
+    {BLOOM_FILTER_PREFIX_USEFUL, "rocksdb.bloom.filter.prefix.useful"},
+    {NUMBER_OF_RESEEKS_IN_ITERATION, "rocksdb.number.reseeks.iteration"},
+    {GET_UPDATES_SINCE_CALLS, "rocksdb.getupdatessince.calls"},
+    {BLOCK_CACHE_COMPRESSED_MISS, "rocksdb.block.cachecompressed.miss"},
+    {BLOCK_CACHE_COMPRESSED_HIT, "rocksdb.block.cachecompressed.hit"},
+    {WAL_FILE_SYNCED, "rocksdb.wal.synced"},
+    {WAL_FILE_BYTES, "rocksdb.wal.bytes"},
+    {WRITE_DONE_BY_SELF, "rocksdb.write.self"},
+    {WRITE_DONE_BY_OTHER, "rocksdb.write.other"},
+    {WRITE_WITH_WAL, "rocksdb.write.wal"},
+    {COMPACT_READ_BYTES, "rocksdb.compact.read.bytes"},
+    {COMPACT_WRITE_BYTES, "rocksdb.compact.write.bytes"},
+    {NUMBER_DIRECT_LOAD_TABLE_PROPERTIES,
+     "rocksdb.number.direct.load.table.properties"},
+    {NUMBER_SUPERVERSION_ACQUIRES, "rocksdb.number.superversion_acquires"},
+    {NUMBER_SUPERVERSION_RELEASES, "rocksdb.number.superversion_releases"},
+    {NUMBER_SUPERVERSION_CLEANUPS, "rocksdb.number.superversion_cleanups"},
 };

 /**
@@ -252,7 +255,7 @@ class Statistics {
  virtual void setTickerCount(Tickers tickerType, uint64_t count) = 0;
  virtual void measureTime(Histograms histogramType, uint64_t time) = 0;

-  virtual void histogramData(Histograms type, HistogramData * const data) = 0;
+  virtual void histogramData(Histograms type, HistogramData* const data) = 0;
  // String representation of the statistic object.
  std::string ToString();
 };
@@ -61,6 +61,10 @@ class Status {
  static Status Incomplete(const Slice& msg, const Slice& msg2 = Slice()) {
    return Status(kIncomplete, msg, msg2);
  }
+  static Status ShutdownInProgress(const Slice& msg,
+                                   const Slice& msg2 = Slice()) {
+    return Status(kShutdownInProgress, msg, msg2);
+  }

  // Returns true iff the status indicates success.
  bool ok() const { return code() == kOk; }
@@ -86,6 +90,9 @@ class Status {
  // Returns true iff the status indicates Incomplete
  bool IsIncomplete() const { return code() == kIncomplete; }

+  // Returns true iff the status indicates Incomplete
+  bool IsShutdownInProgress() const { return code() == kShutdownInProgress; }
+
  // Return a string representation of this status suitable for printing.
  // Returns the string "OK" for success.
  std::string ToString() const;
@@ -99,7 +106,8 @@ class Status {
    kInvalidArgument = 4,
    kIOError = 5,
    kMergeInProgress = 6,
-    kIncomplete = 7
+    kIncomplete = 7,
+    kShutdownInProgress = 8
  };

  // A nullptr state_ (which is always the case for OK) means the message
@@ -1,127 +1,120 @@
-//  Copyright (c) 2013, 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.
-//
 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// Currently we support two types of tables: plain table and block-based table.
+//   1. Block-based table: this is the default table type that we inherited from
+//      LevelDB, which was designed for storing data in hard disk or flash
+//      device.
+//   2. Plain table: it is one of RocksDB's SST file format optimized
+//      for low query latency on pure-memory or really low-latency media.
+//
+// A tutorial of rocksdb table formats is available here:
+//   https://github.com/facebook/rocksdb/wiki/A-Tutorial-of-RocksDB-SST-formats
+//
+// Example code is also available
+//   https://github.com/facebook/rocksdb/wiki/A-Tutorial-of-RocksDB-SST-formats#wiki-examples

 #pragma once
 #include <memory>
-#include <stdint.h>
+#include <string>
+#include <unordered_map>
+
 #include "rocksdb/env.h"
 #include "rocksdb/iterator.h"
-#include "rocksdb/table_properties.h"
 #include "rocksdb/options.h"
+#include "rocksdb/status.h"

 namespace rocksdb {

-struct Options;
+// -- Block-based Table
+class FlushBlockPolicyFactory;
 class RandomAccessFile;
-struct ReadOptions;
-class TableCache;
+class TableBuilder;
+class TableReader;
 class WritableFile;
+struct EnvOptions;
+struct Options;

 using std::unique_ptr;

-// TableBuilder provides the interface used to build a Table
-// (an immutable and sorted map from keys to values).
-//
-// Multiple threads can invoke const methods on a TableBuilder without
-// external synchronization, but if any of the threads may call a
-// non-const method, all threads accessing the same TableBuilder must use
-// external synchronization.
-class TableBuilder {
- public:
-  // REQUIRES: Either Finish() or Abandon() has been called.
-  virtual ~TableBuilder() {}
+// For advanced user only
+struct BlockBasedTableOptions {
+  // @flush_block_policy_factory creates the instances of flush block policy.
+  // which provides a configurable way to determine when to flush a block in
+  // the block based tables.  If not set, table builder will use the default
+  // block flush policy, which cut blocks by block size (please refer to
+  // `FlushBlockBySizePolicy`).
+  std::shared_ptr<FlushBlockPolicyFactory> flush_block_policy_factory;

-  // Add key,value to the table being constructed.
-  // REQUIRES: key is after any previously added key according to comparator.
-  // REQUIRES: Finish(), Abandon() have not been called
-  virtual void Add(const Slice& key, const Slice& value) = 0;
+  // TODO(kailiu) Temporarily disable this feature by making the default value
+  // to be false.
+  //
+  // Indicating if we'd put index/filter blocks to the block cache.
+  // If not specified, each "table reader" object will pre-load index/filter
+  // block during table initialization.
+  bool cache_index_and_filter_blocks = false;

-  // Return non-ok iff some error has been detected.
-  virtual Status status() const = 0;
+  // The index type that will be used for this table.
+  enum IndexType : char {
+    // A space efficient index block that is optimized for
+    // binary-search-based index.
+    kBinarySearch,
+  };

-  // Finish building the table.
-  // REQUIRES: Finish(), Abandon() have not been called
-  virtual Status Finish() = 0;
-
-  // Indicate that the contents of this builder should be abandoned.
-  // If the caller is not going to call Finish(), it must call Abandon()
-  // before destroying this builder.
-  // REQUIRES: Finish(), Abandon() have not been called
-  virtual void Abandon() = 0;
-
-  // Number of calls to Add() so far.
-  virtual uint64_t NumEntries() const = 0;
-
-  // Size of the file generated so far.  If invoked after a successful
-  // Finish() call, returns the size of the final generated file.
-  virtual uint64_t FileSize() const = 0;
+  IndexType index_type = kBinarySearch;
 };

-// A Table is a sorted map from strings to strings.  Tables are
-// immutable and persistent.  A Table may be safely accessed from
-// multiple threads without external synchronization.
-class TableReader {
- public:
-  virtual ~TableReader() {}
-
-  // Determine whether there is a chance that the current table file
-  // contains the key a key starting with iternal_prefix. The specific
-  // table implementation can use bloom filter and/or other heuristic
-  // to filter out this table as a whole.
-  virtual bool PrefixMayMatch(const Slice& internal_prefix) = 0;
-
-  // Returns a new iterator over the table contents.
-  // The result of NewIterator() is initially invalid (caller must
-  // call one of the Seek methods on the iterator before using it).
-  virtual Iterator* NewIterator(const ReadOptions&) = 0;
-
-  // Given a key, return an approximate byte offset in the file where
-  // the data for that key begins (or would begin if the key were
-  // present in the file).  The returned value is in terms of file
-  // bytes, and so includes effects like compression of the underlying data.
-  // E.g., the approximate offset of the last key in the table will
-  // be close to the file length.
-  virtual uint64_t ApproximateOffsetOf(const Slice& key) = 0;
-
-  // Returns true if the block for the specified key is in cache.
-  // REQUIRES: key is in this table.
-  virtual bool TEST_KeyInCache(const ReadOptions& options,
-                               const Slice& key) = 0;
-
-  // Set up the table for Compaction. Might change some parameters with
-  // posix_fadvise
-  virtual void SetupForCompaction() = 0;
-
-  virtual TableProperties& GetTableProperties() = 0;
-
-  // Calls (*result_handler)(handle_context, ...) repeatedly, starting with
-  // the entry found after a call to Seek(key), until result_handler returns
-  // false, where k is the actual internal key for a row found and v as the
-  // value of the key. didIO is true if I/O is involved in the operation. May
-  // not make such a call if filter policy says that key is not present.
-  //
-  // mark_key_may_exist_handler needs to be called when it is configured to be
-  // memory only and the key is not found in the block cache, with
-  // the parameter to be handle_context.
-  //
-  // readOptions is the options for the read
-  // key is the key to search for
-  virtual Status Get(
-      const ReadOptions& readOptions,
-      const Slice& key,
-      void* handle_context,
-      bool (*result_handler)(void* handle_context, const Slice& k,
-                             const Slice& v, bool didIO),
-      void (*mark_key_may_exist_handler)(void* handle_context) = nullptr) = 0;
+// Table Properties that are specific to block-based table properties.
+struct BlockBasedTablePropertyNames {
+  // value of this propertis is a fixed int32 number.
+  static const std::string kIndexType;
 };

-// A base class for table factories
+// Create default block based table factory.
+extern TableFactory* NewBlockBasedTableFactory(
+    const BlockBasedTableOptions& table_options = BlockBasedTableOptions());
+
+// -- Plain Table with prefix-only seek
+// For this factory, you need to set Options.prefix_extrator properly to make it
+// work. Look-up will starts with prefix hash lookup for key prefix. Inside the
+// hash bucket found, a binary search is executed for hash conflicts. Finally,
+// a linear search is used.
+// @user_key_len: plain table has optimization for fix-sized keys, which can be
+//                specified via user_key_len.  Alternatively, you can pass
+//                `kPlainTableVariableLength` if your keys have variable
+//                lengths.
+// @bloom_bits_per_key: the number of bits used for bloom filer per prefix. You
+//                      may disable it by passing a zero.
+// @hash_table_ratio: the desired utilization of the hash table used for prefix
+//                    hashing. hash_table_ratio = number of prefixes / #buckets
+//                    in the hash table
+// @index_sparseness: inside each prefix, need to build one index record for how
+//                    many keys for binary search inside each hash bucket.
+const uint32_t kPlainTableVariableLength = 0;
+extern TableFactory* NewPlainTableFactory(uint32_t user_key_len =
+                                              kPlainTableVariableLength,
+                                          int bloom_bits_per_prefix = 10,
+                                          double hash_table_ratio = 0.75,
+                                          size_t index_sparseness = 16);
+
+// -- Plain Table
+// This factory of plain table ignores Options.prefix_extractor and assumes no
+// hashable prefix available to the key structure. Lookup will be based on
+// binary search index only. Total order seek() can be issued.
+// @user_key_len: plain table has optimization for fix-sized keys, which can be
+//                specified via user_key_len.  Alternatively, you can pass
+//                `kPlainTableVariableLength` if your keys have variable
+//                lengths.
+// @bloom_bits_per_key: the number of bits used for bloom filer per key. You may
+//                  disable it by passing a zero.
+// @index_sparseness: need to build one index record for how many keys for
+//                    binary search.
+extern TableFactory* NewTotalOrderPlainTableFactory(
+    uint32_t user_key_len = kPlainTableVariableLength,
+    int bloom_bits_per_key = 0, size_t index_sparseness = 16);
+
+// A base class for table factories.
 class TableFactory {
 public:
  virtual ~TableFactory() {}
@@ -139,7 +132,7 @@ class TableFactory {
  // in parameter file. It's the caller's responsibility to make sure
  // file is in the correct format.
  //
-  // GetTableReader() is called in two places:
+  // NewTableReader() is called in two places:
  // (1) TableCache::FindTable() calls the function when table cache miss
  //     and cache the table object returned.
  // (1) SstFileReader (for SST Dump) opens the table and dump the table
@@ -150,9 +143,10 @@ class TableFactory {
  // file is a file handler to handle the file for the table
  // file_size is the physical file size of the file
  // table_reader is the output table reader
-  virtual Status GetTableReader(
+  virtual Status NewTableReader(
      const Options& options, const EnvOptions& soptions,
-      unique_ptr<RandomAccessFile> && file, uint64_t file_size,
+      const InternalKeyComparator& internal_comparator,
+      unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
      unique_ptr<TableReader>* table_reader) const = 0;

  // Return a table builder to write to a file for this table type.
@@ -173,8 +167,9 @@ class TableFactory {
  // file is a handle of a writable file. It is the caller's responsibility to
  // keep the file open and close the file after closing the table builder.
  // compression_type is the compression type to use in this table.
-  virtual TableBuilder* GetTableBuilder(
-      const Options& options, WritableFile* file,
-      CompressionType compression_type) const = 0;
+  virtual TableBuilder* NewTableBuilder(
+      const Options& options, const InternalKeyComparator& internal_comparator,
+      WritableFile* file, CompressionType compression_type) const = 0;
 };
+
 }  // namespace rocksdb
@@ -1,28 +1,34 @@
-// Copyright (c) 2013, 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.
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
 #pragma once

 #include <string>
-#include <unordered_map>
-
+#include <map>
 #include "rocksdb/status.h"

 namespace rocksdb {

+// -- Table Properties
+// Other than basic table properties, each table may also have the user
+// collected properties.
+// The value of the user-collected properties are encoded as raw bytes --
+// users have to interprete these values by themselves.
+// Note: To do prefix seek/scan in `UserCollectedProperties`, you can do
+// something similar to:
+//
+// UserCollectedProperties props = ...;
+// for (auto pos = props.lower_bound(prefix);
+//      pos != props.end() && pos->first.compare(0, prefix.size(), prefix) == 0;
+//      ++pos) {
+//   ...
+// }
+typedef std::map<std::string, std::string> UserCollectedProperties;
+
 // TableProperties contains a bunch of read-only properties of its associated
 // table.
 struct TableProperties {
 public:
-  // Other than basic table properties, each table may also have the user
-  // collected properties.
-  // The value of the user-collected properties are encoded as raw bytes --
-  // users have to interprete these values by themselves.
-  typedef
-    std::unordered_map<std::string, std::string>
-    UserCollectedProperties;
-
  // the total size of all data blocks.
  uint64_t data_size = 0;
  // the size of index block.
@@ -37,6 +43,10 @@ struct TableProperties {
  uint64_t num_data_blocks = 0;
  // the number of entries in this table
  uint64_t num_entries = 0;
+  // format version, reserved for backward compatibility
+  uint64_t format_version = 0;
+  // If 0, key is variable length. Otherwise number of bytes for each key.
+  uint64_t fixed_key_len = 0;

  // The name of the filter policy used in this table.
  // If no filter policy is used, `filter_policy_name` will be an empty string.
@@ -47,17 +57,32 @@ struct TableProperties {

  // convert this object to a human readable form
  //   @prop_delim: delimiter for each property.
-  std::string ToString(
-      const std::string& prop_delim = "; ",
-      const std::string& kv_delim = "=") const;
+  std::string ToString(const std::string& prop_delim = "; ",
+                       const std::string& kv_delim = "=") const;
 };

+// table properties' human-readable names in the property block.
+struct TablePropertiesNames {
+  static const std::string kDataSize;
+  static const std::string kIndexSize;
+  static const std::string kFilterSize;
+  static const std::string kRawKeySize;
+  static const std::string kRawValueSize;
+  static const std::string kNumDataBlocks;
+  static const std::string kNumEntries;
+  static const std::string kFormatVersion;
+  static const std::string kFixedKeyLen;
+  static const std::string kFilterPolicy;
+};
+
+extern const std::string kPropertiesBlock;
+
 // `TablePropertiesCollector` provides the mechanism for users to collect
 // their own interested properties. This class is essentially a collection
 //  of callback functions that will be invoked during table building.
 class TablePropertiesCollector {
 public:
-  virtual ~TablePropertiesCollector() { }
+  virtual ~TablePropertiesCollector() {}

  // Add() will be called when a new key/value pair is inserted into the table.
  // @params key    the original key that is inserted into the table.
@@ -68,23 +93,20 @@ class TablePropertiesCollector {
  // for writing the properties block.
  // @params properties  User will add their collected statistics to
  // `properties`.
-  virtual Status Finish(
-      TableProperties::UserCollectedProperties* properties) = 0;
+  virtual Status Finish(UserCollectedProperties* properties) = 0;

  // The name of the properties collector can be used for debugging purpose.
  virtual const char* Name() const = 0;

  // Return the human-readable properties, where the key is property name and
  // the value is the human-readable form of value.
-  virtual TableProperties::UserCollectedProperties
-    GetReadableProperties() const = 0;
+  virtual UserCollectedProperties GetReadableProperties() const = 0;
 };

 // Extra properties
 // Below is a list of non-basic properties that are collected by database
 // itself. Especially some properties regarding to the internal keys (which
 // is unknown to `table`).
-extern uint64_t GetDeletedKeys(
-    const TableProperties::UserCollectedProperties& props);
+extern uint64_t GetDeletedKeys(const UserCollectedProperties& props);

 }  // namespace rocksdb
@@ -85,6 +85,19 @@ class TransactionLogIterator {
  // earliest transaction contained in the batch.
  // ONLY use if Valid() is true and status() is OK.
  virtual BatchResult GetBatch() = 0;
+
+  // The read options for TransactionLogIterator.
+  struct ReadOptions {
+    // If true, all data read from underlying storage will be
+    // verified against corresponding checksums.
+    // Default: true
+    bool verify_checksums_;
+
+    ReadOptions() : verify_checksums_(true) {}
+
+    explicit ReadOptions(bool verify_checksums)
+        : verify_checksums_(verify_checksums) {}
+  };
 };
 } //  namespace rocksdb

@@ -55,17 +55,53 @@ struct BackupableDBOptions {
  // Default: false
  bool destroy_old_data;

+  // If false, we won't backup log files. This option can be useful for backing
+  // up in-memory databases where log file are persisted, but table files are in
+  // memory.
+  // Default: true
+  bool backup_log_files;
+
+  // Max bytes that can be transferred in a second during backup.
+  // If 0, go as fast as you can
+  // Default: 0
+  uint64_t backup_rate_limit;
+
+  // Max bytes that can be transferred in a second during restore.
+  // If 0, go as fast as you can
+  // Default: 0
+  uint64_t restore_rate_limit;
+
+  void Dump(Logger* logger) const;
+
  explicit BackupableDBOptions(const std::string& _backup_dir,
                               Env* _backup_env = nullptr,
                               bool _share_table_files = true,
-                               Logger* _info_log = nullptr,
-                               bool _sync = true,
-                               bool _destroy_old_data = false) :
-      backup_dir(_backup_dir),
-      backup_env(_backup_env),
-      info_log(_info_log),
-      sync(_sync),
-      destroy_old_data(_destroy_old_data) { }
+                               Logger* _info_log = nullptr, bool _sync = true,
+                               bool _destroy_old_data = false,
+                               bool _backup_log_files = true,
+                               uint64_t _backup_rate_limit = 0,
+                               uint64_t _restore_rate_limit = 0)
+      : backup_dir(_backup_dir),
+        backup_env(_backup_env),
+        share_table_files(_share_table_files),
+        info_log(_info_log),
+        sync(_sync),
+        destroy_old_data(_destroy_old_data),
+        backup_log_files(_backup_log_files),
+        backup_rate_limit(_backup_rate_limit),
+        restore_rate_limit(_restore_rate_limit) {}
+};
+
+struct RestoreOptions {
+  // If true, restore won't overwrite the existing log files in wal_dir. It will
+  // also move all log files from archive directory to wal_dir. Use this option
+  // in combination with BackupableDBOptions::backup_log_files = false for
+  // persisting in-memory databases.
+  // Default: false
+  bool keep_log_files;
+
+  explicit RestoreOptions(bool _keep_log_files = false)
+      : keep_log_files(_keep_log_files) {}
 };

 typedef uint32_t BackupID;
@@ -94,13 +130,12 @@ class BackupEngine {
  virtual void StopBackup() = 0;

  virtual void GetBackupInfo(std::vector<BackupInfo>* backup_info) = 0;
-  virtual Status RestoreDBFromBackup(BackupID backup_id,
-                                     const std::string& db_dir,
-                                     const std::string& wal_dir) = 0;
-  virtual Status RestoreDBFromLatestBackup(const std::string& db_dir,
-                                           const std::string& wal_dir) = 0;
-
-  virtual void DeleteBackupsNewerThan(uint64_t sequence_number) = 0;
+  virtual Status RestoreDBFromBackup(
+      BackupID backup_id, const std::string& db_dir, const std::string& wal_dir,
+      const RestoreOptions& restore_options = RestoreOptions()) = 0;
+  virtual Status RestoreDBFromLatestBackup(
+      const std::string& db_dir, const std::string& wal_dir,
+      const RestoreOptions& restore_options = RestoreOptions()) = 0;
 };

 // Stack your DB with BackupableDB to be able to backup the DB
@@ -138,32 +173,37 @@ class BackupableDB : public StackableDB {

 // Use this class to access information about backups and restore from them
 class RestoreBackupableDB {
-  public:
-   RestoreBackupableDB(Env* db_env, const BackupableDBOptions& options);
-   ~RestoreBackupableDB();
+ public:
+  RestoreBackupableDB(Env* db_env, const BackupableDBOptions& options);
+  ~RestoreBackupableDB();

-   // Returns info about backups in backup_info
-   void GetBackupInfo(std::vector<BackupInfo>* backup_info);
+  // Returns info about backups in backup_info
+  void GetBackupInfo(std::vector<BackupInfo>* backup_info);

-   // restore from backup with backup_id
-   // IMPORTANT -- if options_.share_table_files == true and you restore DB
-   // from some backup that is not the latest, and you start creating new
-   // backups from the new DB, all the backups that were newer than the
-   // backup you restored from will be deleted
-   //
-   // Example: Let's say you have backups 1, 2, 3, 4, 5 and you restore 3.
-   // If you try creating a new backup now, old backups 4 and 5 will be deleted
-   // and new backup with ID 4 will be created.
-   Status RestoreDBFromBackup(BackupID backup_id, const std::string& db_dir,
-                              const std::string& wal_dir);
+  // restore from backup with backup_id
+  // IMPORTANT -- if options_.share_table_files == true and you restore DB
+  // from some backup that is not the latest, and you start creating new
+  // backups from the new DB, they will probably fail
+  //
+  // Example: Let's say you have backups 1, 2, 3, 4, 5 and you restore 3.
+  // If you add new data to the DB and try creating a new backup now, the
+  // database will diverge from backups 4 and 5 and the new backup will fail.
+  // If you want to create new backup, you will first have to delete backups 4
+  // and 5.
+  Status RestoreDBFromBackup(BackupID backup_id, const std::string& db_dir,
+                             const std::string& wal_dir,
+                             const RestoreOptions& restore_options =
+                                 RestoreOptions());

-   // restore from the latest backup
-   Status RestoreDBFromLatestBackup(const std::string& db_dir,
-                                    const std::string& wal_dir);
-   // deletes old backups, keeping latest num_backups_to_keep alive
-   Status PurgeOldBackups(uint32_t num_backups_to_keep);
-   // deletes a specific backup
-   Status DeleteBackup(BackupID backup_id);
+  // restore from the latest backup
+  Status RestoreDBFromLatestBackup(const std::string& db_dir,
+                                   const std::string& wal_dir,
+                                   const RestoreOptions& restore_options =
+                                       RestoreOptions());
+  // deletes old backups, keeping latest num_backups_to_keep alive
+  Status PurgeOldBackups(uint32_t num_backups_to_keep);
+  // deletes a specific backup
+  Status DeleteBackup(BackupID backup_id);

 private:
  BackupEngine* backup_engine_;
@@ -0,0 +1,103 @@
+//  Copyright (c) 2013, 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.
+//
+
+#pragma once
+#include <string>
+#include <vector>
+
+#include "utilities/stackable_db.h"
+#include "rocksdb/status.h"
+
+namespace rocksdb {
+
+//
+// Configurable options needed for setting up a Geo database
+//
+struct GeoDBOptions {
+  // Backup info and error messages will be written to info_log
+  // if non-nullptr.
+  // Default: nullptr
+  Logger* info_log;
+
+  explicit GeoDBOptions(Logger* _info_log = nullptr):info_log(_info_log) { }
+};
+
+//
+// A position in the earth's geoid
+//
+class GeoPosition {
+ public:
+  double latitude;
+  double longitude;
+
+  explicit GeoPosition(double la = 0, double lo = 0) :
+    latitude(la), longitude(lo) {
+  }
+};
+
+//
+// Description of an object on the Geoid. It is located by a GPS location,
+// and is identified by the id. The value associated with this object is
+// an opaque string 'value'. Different objects identified by unique id's
+// can have the same gps-location associated with them.
+//
+class GeoObject {
+ public:
+  GeoPosition position;
+  std::string id;
+  std::string value;
+
+  GeoObject() {}
+
+  GeoObject(const GeoPosition& pos, const std::string& i,
+            const std::string& val) :
+    position(pos), id(i), value(val) {
+  }
+};
+
+//
+// Stack your DB with GeoDB to be able to get geo-spatial support
+//
+class GeoDB : public StackableDB {
+ public:
+  // GeoDBOptions have to be the same as the ones used in a previous
+  // incarnation of the DB
+  //
+  // GeoDB owns the pointer `DB* db` now. You should not delete it or
+  // use it after the invocation of GeoDB
+  // GeoDB(DB* db, const GeoDBOptions& options) : StackableDB(db) {}
+  GeoDB(DB* db, const GeoDBOptions& options) : StackableDB(db) {}
+  virtual ~GeoDB() {}
+
+  // Insert a new object into the location database. The object is
+  // uniquely identified by the id. If an object with the same id already
+  // exists in the db, then the old one is overwritten by the new
+  // object being inserted here.
+  virtual Status Insert(const GeoObject& object) = 0;
+
+  // Retrieve the value of the object located at the specified GPS
+  // location and is identified by the 'id'.
+  virtual Status GetByPosition(const GeoPosition& pos,
+                               const Slice& id, std::string* value) = 0;
+
+  // Retrieve the value of the object identified by the 'id'. This method
+  // could be potentially slower than GetByPosition
+  virtual Status GetById(const Slice& id, GeoObject*  object) = 0;
+
+  // Delete the specified object
+  virtual Status Remove(const Slice& id) = 0;
+
+  // Returns a list of all items within a circular radius from the
+  // specified gps location. If 'number_of_values' is specified,
+  // then this call returns at most that many number of objects.
+  // The radius is specified in 'meters'.
+  virtual Status SearchRadial(const GeoPosition& pos,
+                              double radius,
+                              std::vector<GeoObject>* values,
+                              int number_of_values = INT_MAX) = 0;
+};
+
+}  // namespace rocksdb
@@ -148,10 +148,14 @@ class StackableDB : public DB {
    return db_->GetDbIdentity(identity);
  }

-  virtual Status GetUpdatesSince(SequenceNumber seq_number,
-                                 unique_ptr<TransactionLogIterator>* iter)
-    override {
-      return db_->GetUpdatesSince(seq_number, iter);
+  virtual Status GetPropertiesOfAllTables(TablePropertiesCollection* props) {
+    return db_->GetPropertiesOfAllTables(props);
+  }
+
+  virtual Status GetUpdatesSince(
+      SequenceNumber seq_number, unique_ptr<TransactionLogIterator>* iter,
+      const TransactionLogIterator::ReadOptions& read_options) override {
+    return db_->GetUpdatesSince(seq_number, iter, read_options);
  }

 protected:
@@ -0,0 +1,24 @@
+NATIVE_JAVA_CLASSES = org.rocksdb.RocksDB org.rocksdb.Options org.rocksdb.WriteBatch org.rocksdb.WriteBatchInternal org.rocksdb.WriteBatchTest org.rocksdb.WriteOptions
+NATIVE_INCLUDE = ./include
+ROCKSDB_JAR = rocksdbjni.jar
+
+clean:
+	-find . -name "*.class" -exec rm {} \;
+	-find . -name "hs*.log" -exec rm {} \;
+	rm -f $(ROCKSDB_JAR)
+
+java:
+	javac org/rocksdb/*.java
+	jar -cf $(ROCKSDB_JAR) org/rocksdb/*.class
+	javah -d $(NATIVE_INCLUDE) -jni $(NATIVE_JAVA_CLASSES)
+
+sample:
+	javac -cp $(ROCKSDB_JAR) RocksDBSample.java
+	@rm -rf /tmp/rocksdbjni
+	@rm -rf /tmp/rocksdbjni_not_found
+	java -ea -Djava.library.path=.:../ -cp ".:./*" RocksDBSample /tmp/rocksdbjni
+	@rm -rf /tmp/rocksdbjni
+	@rm -rf /tmp/rocksdbjni_not_found
+
+test:
+	java -ea -Djava.library.path=.:../ -cp "$(ROCKSDB_JAR):.:./*" org.rocksdb.WriteBatchTest
@@ -0,0 +1,118 @@
+// Copyright (c) 2014, 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.
+
+import java.util.*;
+import java.lang.*;
+import org.rocksdb.*;
+import java.io.IOException;
+
+public class RocksDBSample {
+  static {
+    System.loadLibrary("rocksdbjni");
+  }
+
+  public static void main(String[] args) {
+    if (args.length < 1) {
+      System.out.println("usage: RocksDBSample db_path");
+      return;
+    }
+    String db_path = args[0];
+    String db_path_not_found = db_path + "_not_found";
+
+    System.out.println("RocksDBSample");
+    RocksDB db = null;
+    Options options = new Options();
+    try {
+      db = RocksDB.open(options, db_path_not_found);
+      assert(false);
+    } catch (RocksDBException e) {
+      System.out.format("caught the expceted exception -- %s\n", e);
+      assert(db == null);
+    }
+
+    options.setCreateIfMissing(true);
+    try {
+      db = RocksDB.open(options, db_path_not_found);
+      db.put("hello".getBytes(), "world".getBytes());
+      byte[] value = db.get("hello".getBytes());
+      assert("world".equals(new String(value)));
+    } catch (RocksDBException e) {
+      System.out.format("[ERROR] caught the unexpceted exception -- %s\n", e);
+      assert(db == null);
+      assert(false);
+    }
+
+    // be sure to release the c++ pointer
+    options.dispose();
+    db.close();
+
+    try {
+      db = RocksDB.open(db_path);
+      db.put("hello".getBytes(), "world".getBytes());
+      byte[] value = db.get("hello".getBytes());
+      System.out.format("Get('hello') = %s\n",
+          new String(value));
+
+      for (int i = 1; i <= 9; ++i) {
+        for (int j = 1; j <= 9; ++j) {
+          db.put(String.format("%dx%d", i, j).getBytes(),
+                 String.format("%d", i * j).getBytes());
+        }
+      }
+
+      for (int i = 1; i <= 9; ++i) {
+        for (int j = 1; j <= 9; ++j) {
+          System.out.format("%s ", new String(db.get(
+              String.format("%dx%d", i, j).getBytes())));
+        }
+        System.out.println("");
+      }
+
+      value = db.get("1x1".getBytes());
+      assert(value != null);
+      value = db.get("world".getBytes());
+      assert(value == null);
+
+      byte[] testKey = "asdf".getBytes();
+      byte[] testValue =
+          "asdfghjkl;'?><MNBVCXZQWERTYUIOP{+_)(*&^%$#@".getBytes();
+      db.put(testKey, testValue);
+      byte[] testResult = db.get(testKey);
+      assert(testResult != null);
+      assert(Arrays.equals(testValue, testResult));
+      assert(new String(testValue).equals(new String(testResult)));
+
+      byte[] insufficientArray = new byte[10];
+      byte[] enoughArray = new byte[50];
+      int len;
+      len = db.get(testKey, insufficientArray);
+      assert(len > insufficientArray.length);
+      len = db.get("asdfjkl;".getBytes(), enoughArray);
+      assert(len == RocksDB.NOT_FOUND);
+      len = db.get(testKey, enoughArray);
+      assert(len == testValue.length);
+
+      db.remove(testKey);
+      len = db.get(testKey, enoughArray);
+      assert(len == RocksDB.NOT_FOUND);
+
+      // repeat the test with WriteOptions
+      WriteOptions writeOpts = new WriteOptions();
+      writeOpts.setSync(true);
+      writeOpts.setDisableWAL(true);
+      db.put(writeOpts, testKey, testValue);
+      len = db.get(testKey, enoughArray);
+      assert(len == testValue.length);
+      assert(new String(testValue).equals(
+          new String(enoughArray, 0, len)));
+      writeOpts.dispose();
+    } catch (RocksDBException e) {
+      System.err.println(e);
+    }
+    if (db != null) {
+      db.close();
+    }
+  }
+}
@@ -0,0 +1,69 @@
+// Copyright (c) 2014, 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.
+
+package org.rocksdb;
+
+/**
+ * Options to control the behavior of a database.  It will be used
+ * during the creation of a RocksDB (i.e., RocksDB::Open()).
+ *
+ * Note that dispose() must be called before an Options instance
+ * become out-of-scope to release the allocated memory in c++.
+ */
+public class Options {
+  /**
+   * Construct options for opening a RocksDB.
+   *
+   * This constructor will create (by allocating a block of memory)
+   * an rocksdb::Options in the c++ side.
+   */
+  public Options() {
+    nativeHandle_ = 0;
+    newOptions();
+  }
+
+  /**
+   * If this value is set to true, then the database will be created
+   * if it is missing during RocksDB::Open().
+   * Default: false
+   *
+   * @param flag a flag indicating whether to create a database the
+   *     specified database in RocksDB::Open() operation is missing.
+   * @see RocksDB::Open()
+   */
+  public void setCreateIfMissing(boolean flag) {
+    assert(nativeHandle_ != 0);
+    setCreateIfMissing(nativeHandle_, flag);
+  }
+
+  /**
+   * Return true if the create_if_missing flag is set to true.
+   * If true, the database will be created if it is missing.
+   *
+   * @return return true if the create_if_missing flag is set to true.
+   * @see setCreateIfMissing()
+   */
+  public boolean craeteIfMissing() {
+    assert(nativeHandle_ != 0);
+    return createIfMissing(nativeHandle_);
+  }
+
+  /**
+   * Release the memory allocated for the current instance
+   * in the c++ side.
+   */
+  public synchronized void dispose() {
+    if (nativeHandle_ != 0) {
+      dispose0();
+    }
+  }
+
+  private native void newOptions();
+  private native void dispose0();
+  private native void setCreateIfMissing(long handle, boolean flag);
+  private native boolean createIfMissing(long handle);
+
+  long nativeHandle_;
+}
@@ -0,0 +1,163 @@
+// Copyright (c) 2014, 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.
+
+package org.rocksdb;
+
+import java.lang.*;
+import java.util.*;
+import java.io.Closeable;
+import java.io.IOException;
+
+/**
+ * A RocksDB is a persistent ordered map from keys to values.  It is safe for
+ * concurrent access from multiple threads without any external synchronization.
+ * All methods of this class could potentially throw RocksDBException, which
+ * indicates sth wrong at the rocksdb library side and the call failed.
+ */
+public class RocksDB {
+  public static final int NOT_FOUND = -1;
+  /**
+   * The factory constructor of RocksDB that opens a RocksDB instance given
+   * the path to the database using the default options w/ createIfMissing
+   * set to true.
+   *
+   * @param path the path to the rocksdb.
+   * @param status an out value indicating the status of the Open().
+   * @return a rocksdb instance on success, null if the specified rocksdb can
+   *     not be opened.
+   *
+   * @see Options.setCreateIfMissing()
+   * @see Options.createIfMissing()
+   */
+  public static RocksDB open(String path) throws RocksDBException {
+    RocksDB db = new RocksDB();
+    db.open0(path);
+    return db;
+  }
+
+  /**
+   * The factory constructor of RocksDB that opens a RocksDB instance given
+   * the path to the database using the specified options and db path.
+   */
+  public static RocksDB open(Options options, String path)
+      throws RocksDBException {
+    RocksDB db = new RocksDB();
+    db.open(options.nativeHandle_, path);
+    return db;
+  }
+
+  public synchronized void close() {
+    if (nativeHandle_ != 0) {
+      close0();
+    }
+  }
+
+  /**
+   * Set the database entry for "key" to "value".
+   *
+   * @param key the specified key to be inserted.
+   * @param value the value associated with the specified key.
+   */
+  public void put(byte[] key, byte[] value) throws RocksDBException {
+    put(nativeHandle_, key, key.length, value, value.length);
+  }
+
+  /**
+   * Set the database entry for "key" to "value".
+   *
+   * @param key the specified key to be inserted.
+   * @param value the value associated with the specified key.
+   */
+  public void put(WriteOptions writeOpts, byte[] key, byte[] value)
+      throws RocksDBException {
+    put(nativeHandle_, writeOpts.nativeHandle_, key, key.length, value, value.length);
+  }
+
+  /**
+   * Get the value associated with the specified key.
+   *
+   * @param key the key to retrieve the value.
+   * @param value the out-value to receive the retrieved value.
+   * @return The size of the actual value that matches the specified
+   *     {@code key} in byte.  If the return value is greater than the
+   *     length of {@code value}, then it indicates that the size of the
+   *     input buffer {@code value} is insufficient and partial result will
+   *     be returned.  RocksDB.NOT_FOUND will be returned if the value not
+   *     found.
+   */
+  public int get(byte[] key, byte[] value) throws RocksDBException {
+    return get(nativeHandle_, key, key.length, value, value.length);
+  }
+
+  /**
+   * The simplified version of get which returns a new byte array storing
+   * the value associated with the specified input key if any.  null will be
+   * returned if the specified key is not found.
+   *
+   * @param key the key retrieve the value.
+   * @return a byte array storing the value associated with the input key if
+   *     any.  null if it does not find the specified key.
+   *
+   * @see RocksDBException
+   */
+  public byte[] get(byte[] key) throws RocksDBException {
+    return get(nativeHandle_, key, key.length);
+  }
+
+  /**
+   * Remove the database entry (if any) for "key".  Returns OK on
+   * success, and a non-OK status on error.  It is not an error if "key"
+   * did not exist in the database.
+   */
+  public void remove(byte[] key) throws RocksDBException {
+    remove(nativeHandle_, key, key.length);
+  }
+
+  /**
+   * Remove the database entry (if any) for "key".  Returns OK on
+   * success, and a non-OK status on error.  It is not an error if "key"
+   * did not exist in the database.
+   */
+  public void remove(WriteOptions writeOpt, byte[] key)
+      throws RocksDBException {
+    remove(nativeHandle_, writeOpt.nativeHandle_, key, key.length);
+  }
+
+  @Override protected void finalize() {
+    close();
+  }
+
+  /**
+   * Private constructor.
+   */
+  private RocksDB() {
+    nativeHandle_ = 0;
+  }
+
+  // native methods
+  private native void open0(String path) throws RocksDBException;
+  private native void open(
+      long optionsHandle, String path) throws RocksDBException;
+  private native void put(
+      long handle, byte[] key, int keyLen,
+      byte[] value, int valueLen) throws RocksDBException;
+  private native void put(
+      long handle, long writeOptHandle,
+      byte[] key, int keyLen,
+      byte[] value, int valueLen) throws RocksDBException;
+  private native int get(
+      long handle, byte[] key, int keyLen,
+      byte[] value, int valueLen) throws RocksDBException;
+  private native byte[] get(
+      long handle, byte[] key, int keyLen) throws RocksDBException;
+  private native void remove(
+      long handle, byte[] key, int keyLen) throws RocksDBException;
+  private native void remove(
+      long handle, long writeOptHandle,
+      byte[] key, int keyLen) throws RocksDBException;
+  private native void close0();
+
+  private long nativeHandle_;
+}
@@ -0,0 +1,24 @@
+// Copyright (c) 2013, 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.
+
+package org.rocksdb;
+
+import java.lang.*;
+import java.util.*;
+
+/**
+ * A RocksDBException encapsulates the error of an operation.  This exception
+ * type is used to describe an internal error from the c++ rocksdb library.
+ */
+public class RocksDBException extends Exception {
+  /**
+   * The private construct used by a set of public static factory method.
+   *
+   * @param msg the specified error message.
+   */
+  public RocksDBException(String msg) {
+    super(msg);
+  }
+}
@@ -0,0 +1,121 @@
+// Copyright (c) 2014, 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.
+
+package org.rocksdb;
+
+import java.lang.*;
+import java.util.*;
+
+/**
+ * WriteBatch holds a collection of updates to apply atomically to a DB.
+ *
+ * The updates are applied in the order in which they are added
+ * to the WriteBatch.  For example, the value of "key" will be "v3"
+ * after the following batch is written:
+ *
+ *    batch.put("key", "v1");
+ *    batch.remove("key");
+ *    batch.put("key", "v2");
+ *    batch.put("key", "v3");
+ *
+ * Multiple threads can invoke const methods on a WriteBatch without
+ * external synchronization, but if any of the threads may call a
+ * non-const method, all threads accessing the same WriteBatch must use
+ * external synchronization.
+ */
+public class WriteBatch {
+  public WriteBatch() {
+    nativeHandle_ = 0;
+    newWriteBatch(0);
+  }
+
+  public WriteBatch(int reserved_bytes) {
+    nativeHandle_ = 0;
+    newWriteBatch(reserved_bytes);
+  }
+
+  /**
+   * Returns the number of updates in the batch.
+   */
+  public native int count();
+
+  /**
+   * Store the mapping "key->value" in the database.
+   */
+  public void put(byte[] key, byte[] value) {
+    put(key, key.length, value, value.length);
+  }
+
+  /**
+   * Merge "value" with the existing value of "key" in the database.
+   * "key->merge(existing, value)"
+   */
+  public void merge(byte[] key, byte[] value) {
+    merge(key, key.length, value, value.length);
+  }
+
+  /**
+   * If the database contains a mapping for "key", erase it.  Else do nothing.
+   */
+  public void remove(byte[] key) {
+    remove(key, key.length);
+  }
+
+  /**
+   * Append a blob of arbitrary size to the records in this batch. The blob will
+   * be stored in the transaction log but not in any other file. In particular,
+   * it will not be persisted to the SST files. When iterating over this
+   * WriteBatch, WriteBatch::Handler::LogData will be called with the contents
+   * of the blob as it is encountered. Blobs, puts, deletes, and merges will be
+   * encountered in the same order in thich they were inserted. The blob will
+   * NOT consume sequence number(s) and will NOT increase the count of the batch
+   *
+   * Example application: add timestamps to the transaction log for use in
+   * replication.
+   */
+  public void putLogData(byte[] blob) {
+    putLogData(blob, blob.length);
+  }
+
+  /**
+   * Clear all updates buffered in this batch
+   */
+  public native void clear();
+
+  /**
+   * Delete the c++ side pointer.
+   */
+  public synchronized void dispose() {
+    if (nativeHandle_ != 0) {
+      dispose0();
+    }
+  }
+
+  @Override protected void finalize() {
+    dispose();
+  }
+
+  private native void newWriteBatch(int reserved_bytes);
+  private native void put(byte[] key, int keyLen,
+                          byte[] value, int valueLen);
+  private native void merge(byte[] key, int keyLen,
+                            byte[] value, int valueLen);
+  private native void remove(byte[] key, int keyLen);
+  private native void putLogData(byte[] blob, int blobLen);
+  private native void dispose0();
+
+  private long nativeHandle_;
+}
+
+/**
+ * Package-private class which provides java api to access
+ * c++ WriteBatchInternal.
+ */
+class WriteBatchInternal {
+  static native void setSequence(WriteBatch batch, long sn);
+  static native long sequence(WriteBatch batch);
+  static native void append(WriteBatch b1, WriteBatch b2);
+}
+
@@ -0,0 +1,125 @@
+//  Copyright (c) 2014, 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.
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+package org.rocksdb;
+
+import java.util.*;
+import java.lang.*;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * This class mimics the db/write_batch_test.cc in the c++ rocksdb library.
+ */
+public class WriteBatchTest {
+  static {
+    System.loadLibrary("rocksdbjni");
+  }
+
+  public static void main(String args[]) {
+    System.out.println("Testing WriteBatchTest.Empty ===");
+    Empty();
+
+    System.out.println("Testing WriteBatchTest.Multiple ===");
+    Multiple();
+
+    System.out.println("Testing WriteBatchTest.Append ===");
+    Append();
+
+    System.out.println("Testing WriteBatchTest.Blob ===");
+    Blob();
+
+    // The following tests have not yet ported.
+    // Continue();
+    // PutGatherSlices();
+
+    System.out.println("Passed all WriteBatchTest!");
+  }
+
+  static void Empty() {
+    WriteBatch batch = new WriteBatch();
+    assert(batch.count() == 0);
+  }
+
+  static void Multiple() {
+    try {
+      WriteBatch batch =  new WriteBatch();
+      batch.put("foo".getBytes("US-ASCII"), "bar".getBytes("US-ASCII"));
+      batch.remove("box".getBytes("US-ASCII"));
+      batch.put("baz".getBytes("US-ASCII"), "boo".getBytes("US-ASCII"));
+      WriteBatchInternal.setSequence(batch, 100);
+      assert(100 == WriteBatchInternal.sequence(batch));
+      assert(3 == batch.count());
+      assert(new String("Put(baz, boo)@102" +
+                        "Delete(box)@101" +
+                        "Put(foo, bar)@100")
+                .equals(new String(getContents(batch), "US-ASCII")));
+    } catch (UnsupportedEncodingException e) {
+      System.err.println(e);
+      assert(false);
+    }
+  }
+
+  static void Append() {
+    WriteBatch b1 = new WriteBatch();
+    WriteBatch b2 = new WriteBatch();
+    WriteBatchInternal.setSequence(b1, 200);
+    WriteBatchInternal.setSequence(b2, 300);
+    WriteBatchInternal.append(b1, b2);
+    assert(getContents(b1).length == 0);
+    assert(b1.count() == 0);
+    try {
+      b2.put("a".getBytes("US-ASCII"), "va".getBytes("US-ASCII"));
+      WriteBatchInternal.append(b1, b2);
+      assert("Put(a, va)@200".equals(new String(getContents(b1), "US-ASCII")));
+      assert(1 == b1.count());
+      b2.clear();
+      b2.put("b".getBytes("US-ASCII"), "vb".getBytes("US-ASCII"));
+      WriteBatchInternal.append(b1, b2);
+      assert(new String("Put(a, va)@200" +
+                        "Put(b, vb)@201")
+                .equals(new String(getContents(b1), "US-ASCII")));
+      assert(2 == b1.count());
+      b2.remove("foo".getBytes("US-ASCII"));
+      WriteBatchInternal.append(b1, b2);
+      assert(new String("Put(a, va)@200" +
+                        "Put(b, vb)@202" +
+                        "Put(b, vb)@201" +
+                        "Delete(foo)@203")
+                 .equals(new String(getContents(b1), "US-ASCII")));
+      assert(4 == b1.count());
+    } catch (UnsupportedEncodingException e) {
+      System.err.println(e);
+      assert(false);
+    }
+  }
+
+  static void Blob() {
+    WriteBatch batch = new WriteBatch();
+    try {
+      batch.put("k1".getBytes("US-ASCII"), "v1".getBytes("US-ASCII"));
+      batch.put("k2".getBytes("US-ASCII"), "v2".getBytes("US-ASCII"));
+      batch.put("k3".getBytes("US-ASCII"), "v3".getBytes("US-ASCII"));
+      batch.putLogData("blob1".getBytes("US-ASCII"));
+      batch.remove("k2".getBytes("US-ASCII"));
+      batch.putLogData("blob2".getBytes("US-ASCII"));
+      batch.merge("foo".getBytes("US-ASCII"), "bar".getBytes("US-ASCII"));
+      assert(5 == batch.count());
+      assert(new String("Merge(foo, bar)@4" +
+                        "Put(k1, v1)@0" +
+                        "Delete(k2)@3" +
+                        "Put(k2, v2)@1" +
+                        "Put(k3, v3)@2")
+                .equals(new String(getContents(batch), "US-ASCII")));
+    } catch (UnsupportedEncodingException e) {
+      System.err.println(e);
+      assert(false);
+    }
+  }
+
+  static native byte[] getContents(WriteBatch batch);
+}
@@ -0,0 +1,96 @@
+// Copyright (c) 2014, 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.
+
+package org.rocksdb;
+
+/**
+ * Options that control write operations.
+ *
+ * Note that developers should call WriteOptions.dispose() to release the
+ * c++ side memory before a WriteOptions instance runs out of scope.
+ */
+public class WriteOptions {
+  public WriteOptions() {
+    nativeHandle_ = 0;
+    newWriteOptions();
+  }
+
+  public synchronized void dispose() {
+    if (nativeHandle_ != 0) {
+      dispose0(nativeHandle_);
+    }
+  }
+
+  /**
+   * If true, the write will be flushed from the operating system
+   * buffer cache (by calling WritableFile::Sync()) before the write
+   * is considered complete.  If this flag is true, writes will be
+   * slower.
+   *
+   * If this flag is false, and the machine crashes, some recent
+   * writes may be lost.  Note that if it is just the process that
+   * crashes (i.e., the machine does not reboot), no writes will be
+   * lost even if sync==false.
+   *
+   * In other words, a DB write with sync==false has similar
+   * crash semantics as the "write()" system call.  A DB write
+   * with sync==true has similar crash semantics to a "write()"
+   * system call followed by "fdatasync()".
+   *
+   * Default: false
+   */
+  public void setSync(boolean flag) {
+    setSync(nativeHandle_, flag);
+  }
+
+  /**
+   * If true, the write will be flushed from the operating system
+   * buffer cache (by calling WritableFile::Sync()) before the write
+   * is considered complete.  If this flag is true, writes will be
+   * slower.
+   *
+   * If this flag is false, and the machine crashes, some recent
+   * writes may be lost.  Note that if it is just the process that
+   * crashes (i.e., the machine does not reboot), no writes will be
+   * lost even if sync==false.
+   *
+   * In other words, a DB write with sync==false has similar
+   * crash semantics as the "write()" system call.  A DB write
+   * with sync==true has similar crash semantics to a "write()"
+   * system call followed by "fdatasync()".
+   */
+  public boolean sync() {
+    return sync(nativeHandle_);
+  }
+
+  /**
+   * If true, writes will not first go to the write ahead log,
+   * and the write may got lost after a crash.
+   */
+  public void setDisableWAL(boolean flag) {
+    setDisableWAL(nativeHandle_, flag);
+  }
+
+  /**
+   * If true, writes will not first go to the write ahead log,
+   * and the write may got lost after a crash.
+   */
+  public boolean disableWAL() {
+    return disableWAL(nativeHandle_);
+  }
+
+  @Override protected void finalize() {
+    dispose();
+  }
+
+  private native void newWriteOptions();
+  private native void setSync(long handle, boolean flag);
+  private native boolean sync(long handle);
+  private native void setDisableWAL(long handle, boolean flag);
+  private native boolean disableWAL(long handle);
+  private native void dispose0(long handle);
+
+  protected  long nativeHandle_;
+}
@@ -0,0 +1,128 @@
+// Copyright (c) 2014, 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 file implements the "bridge" between Java and C++ for rocksdb::Options.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+#include <string>
+
+#include "include/org_rocksdb_Options.h"
+#include "include/org_rocksdb_WriteOptions.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/db.h"
+#include "rocksdb/options.h"
+
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    newOptions
+ * Signature: ()V
+ */
+void Java_org_rocksdb_Options_newOptions(JNIEnv* env, jobject jobj) {
+  rocksdb::Options* op = new rocksdb::Options();
+  rocksdb::OptionsJni::setHandle(env, jobj, op);
+}
+
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    dispose0
+ * Signature: ()V
+ */
+void Java_org_rocksdb_Options_dispose0(JNIEnv* env, jobject jobj) {
+  rocksdb::Options* op = rocksdb::OptionsJni::getHandle(env, jobj);
+  delete op;
+
+  rocksdb::OptionsJni::setHandle(env, jobj, op);
+}
+
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    setCreateIfMissing
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_Options_setCreateIfMissing(
+    JNIEnv* env, jobject jobj, jlong jhandle, jboolean flag) {
+  reinterpret_cast<rocksdb::Options*>(jhandle)->create_if_missing = flag;
+}
+
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    createIfMissing
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_Options_createIfMissing(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  return reinterpret_cast<rocksdb::Options*>(jhandle)->create_if_missing;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// WriteOptions
+
+/*
+ * Class:     org_rocksdb_WriteOptions
+ * Method:    newWriteOptions
+ * Signature: ()V
+ */
+void Java_org_rocksdb_WriteOptions_newWriteOptions(
+    JNIEnv* env, jobject jwrite_options) {
+  rocksdb::WriteOptions* op = new rocksdb::WriteOptions();
+  rocksdb::WriteOptionsJni::setHandle(env, jwrite_options, op);
+}
+
+/*
+ * Class:     org_rocksdb_WriteOptions
+ * Method:    dispose0
+ * Signature: ()V
+ */
+void Java_org_rocksdb_WriteOptions_dispose0(
+    JNIEnv* env, jobject jwrite_options, jlong jhandle) {
+  auto write_options = reinterpret_cast<rocksdb::WriteOptions*>(jhandle);
+  delete write_options;
+
+  rocksdb::WriteOptionsJni::setHandle(env, jwrite_options, nullptr);
+}
+
+/*
+ * Class:     org_rocksdb_WriteOptions
+ * Method:    setSync
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_WriteOptions_setSync(
+  JNIEnv* env, jobject jwrite_options, jlong jhandle, jboolean jflag) {
+  reinterpret_cast<rocksdb::WriteOptions*>(jhandle)->sync = jflag;
+}
+
+/*
+ * Class:     org_rocksdb_WriteOptions
+ * Method:    sync
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_WriteOptions_sync(
+    JNIEnv* env, jobject jwrite_options, jlong jhandle) {
+  return reinterpret_cast<rocksdb::WriteOptions*>(jhandle)->sync;
+}
+
+/*
+ * Class:     org_rocksdb_WriteOptions
+ * Method:    setDisableWAL
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_WriteOptions_setDisableWAL(
+    JNIEnv* env, jobject jwrite_options, jlong jhandle, jboolean jflag) {
+  reinterpret_cast<rocksdb::WriteOptions*>(jhandle)->disableWAL = jflag;
+}
+
+/*
+ * Class:     org_rocksdb_WriteOptions
+ * Method:    disableWAL
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_WriteOptions_disableWAL(
+    JNIEnv* env, jobject jwrite_options, jlong jhandle) {
+  return reinterpret_cast<rocksdb::WriteOptions*>(jhandle)->disableWAL;
+}
+
+
@@ -0,0 +1,174 @@
+// Copyright (c) 2014, 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 file is designed for caching those frequently used IDs and provide
+// efficient portal (i.e, a set of static functions) to access java code
+// from c++.
+
+#ifndef JAVA_ROCKSJNI_PORTAL_H_
+#define JAVA_ROCKSJNI_PORTAL_H_
+
+#include <jni.h>
+#include "rocksdb/db.h"
+
+namespace rocksdb {
+
+// The portal class for org.rocksdb.RocksDB
+class RocksDBJni {
+ public:
+  // Get the java class id of org.rocksdb.RocksDB.
+  static jclass getJClass(JNIEnv* env) {
+    static jclass jclazz = env->FindClass("org/rocksdb/RocksDB");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.RocksDB
+  // that stores the pointer to rocksdb::DB.
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::DB of the specified org.rocksdb.RocksDB.
+  static rocksdb::DB* getHandle(JNIEnv* env, jobject jdb) {
+    return reinterpret_cast<rocksdb::DB*>(
+        env->GetLongField(jdb, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::DB pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jdb, rocksdb::DB* db) {
+    env->SetLongField(
+        jdb, getHandleFieldID(env),
+        reinterpret_cast<jlong>(db));
+  }
+};
+
+// The portal class for org.rocksdb.RocksDBException
+class RocksDBExceptionJni {
+ public:
+  // Get the jclass of org.rocksdb.RocksDBException
+  static jclass getJClass(JNIEnv* env) {
+    static jclass jclazz = env->FindClass("org/rocksdb/RocksDBException");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Create and throw a java exception by converting the input
+  // Status to an RocksDBException.
+  //
+  // In case s.ok() is true, then this function will not throw any
+  // exception.
+  static void ThrowNew(JNIEnv* env, Status s) {
+    if (s.ok()) {
+      return;
+    }
+    jstring msg = env->NewStringUTF(s.ToString().c_str());
+    // get the constructor id of org.rocksdb.RocksDBException
+    static jmethodID mid = env->GetMethodID(
+        getJClass(env), "<init>", "(Ljava/lang/String;)V");
+    assert(mid != nullptr);
+
+    env->Throw((jthrowable)env->NewObject(getJClass(env), mid, msg));
+  }
+};
+
+class OptionsJni {
+ public:
+  // Get the java class id of org.rocksdb.Options.
+  static jclass getJClass(JNIEnv* env) {
+    static jclass jclazz = env->FindClass("org/rocksdb/Options");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.Options
+  // that stores the pointer to rocksdb::Options
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::Options
+  static rocksdb::Options* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::Options*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::Options pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jobj, rocksdb::Options* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+class WriteOptionsJni {
+ public:
+  // Get the java class id of org.rocksdb.WriteOptions.
+  static jclass getJClass(JNIEnv* env) {
+    static jclass jclazz = env->FindClass("org/rocksdb/WriteOptions");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.WriteOptions
+  // that stores the pointer to rocksdb::WriteOptions
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::WriteOptions
+  static rocksdb::WriteOptions* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::WriteOptions*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::WriteOptions pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jobj, rocksdb::WriteOptions* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+class WriteBatchJni {
+ public:
+  static jclass getJClass(JNIEnv* env) {
+    static jclass jclazz = env->FindClass("org/rocksdb/WriteBatch");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::WriteBatch of the specified
+  // org.rocksdb.WriteBatch.
+  static rocksdb::WriteBatch* getHandle(JNIEnv* env, jobject jwb) {
+    return reinterpret_cast<rocksdb::WriteBatch*>(
+        env->GetLongField(jwb, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::WriteBatch pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jwb, rocksdb::WriteBatch* wb) {
+    env->SetLongField(
+        jwb, getHandleFieldID(env),
+        reinterpret_cast<jlong>(wb));
+  }
+};
+}  // namespace rocksdb
+#endif  // JAVA_ROCKSJNI_PORTAL_H_
@@ -0,0 +1,285 @@
+// Copyright (c) 2014, 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 file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::DB methods from Java side.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+#include <string>
+
+#include "include/org_rocksdb_RocksDB.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/db.h"
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Open
+
+void rocksdb_open_helper(
+  JNIEnv* env, jobject java_db, jstring jdb_path, const rocksdb::Options& opt) {
+  rocksdb::DB* db;
+
+  const char* db_path = env->GetStringUTFChars(jdb_path, 0);
+  rocksdb::Status s = rocksdb::DB::Open(opt, db_path, &db);
+  env->ReleaseStringUTFChars(jdb_path, db_path);
+
+  if (s.ok()) {
+    rocksdb::RocksDBJni::setHandle(env, java_db, db);
+    return;
+  }
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    open0
+ * Signature: (Ljava/lang/String;)V
+ */
+void Java_org_rocksdb_RocksDB_open0(
+    JNIEnv* env, jobject jdb, jstring jdb_path) {
+  rocksdb::Options options;
+  options.create_if_missing = true;
+
+  rocksdb_open_helper(env, jdb, jdb_path, options);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    open
+ * Signature: (JLjava/lang/String;)V
+ */
+void Java_org_rocksdb_RocksDB_open(
+    JNIEnv* env, jobject jdb, jlong jopt_handle, jstring jdb_path) {
+  auto options = reinterpret_cast<rocksdb::Options*>(jopt_handle);
+  rocksdb_open_helper(env, jdb, jdb_path, *options);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Put
+
+void rocksdb_put_helper(
+    JNIEnv* env, rocksdb::DB* db, const rocksdb::WriteOptions& write_options,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+
+  jbyte* key = env->GetByteArrayElements(jkey, 0);
+  jbyte* value = env->GetByteArrayElements(jvalue, 0);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  rocksdb::Slice value_slice(reinterpret_cast<char*>(value), jvalue_len);
+
+  rocksdb::Status s = db->Put(write_options, key_slice, value_slice);
+
+  // trigger java unref on key and value.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+  env->ReleaseByteArrayElements(jvalue, value, JNI_ABORT);
+
+  if (s.ok()) {
+    return;
+  }
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    put
+ * Signature: (J[BI[BI)V
+ */
+void Java_org_rocksdb_RocksDB_put__J_3BI_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  static const rocksdb::WriteOptions default_write_options =
+      rocksdb::WriteOptions();
+
+  rocksdb_put_helper(env, db, default_write_options,
+                     jkey, jkey_len,
+                     jvalue, jvalue_len);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    put
+ * Signature: (JJ[BI[BI)V
+ */
+void Java_org_rocksdb_RocksDB_put__JJ_3BI_3BI(
+    JNIEnv* env, jobject jdb,
+    jlong jdb_handle, jlong jwrite_options_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  auto write_options = reinterpret_cast<rocksdb::WriteOptions*>(
+      jwrite_options_handle);
+
+  rocksdb_put_helper(env, db, *write_options,
+                     jkey, jkey_len,
+                     jvalue, jvalue_len);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Get
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    get
+ * Signature: (J[BI)[B
+ */
+jbyteArray Java_org_rocksdb_RocksDB_get__J_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+
+  jboolean isCopy;
+  jbyte* key = env->GetByteArrayElements(jkey, &isCopy);
+  rocksdb::Slice key_slice(
+      reinterpret_cast<char*>(key), jkey_len);
+
+  std::string value;
+  rocksdb::Status s = db->Get(
+      rocksdb::ReadOptions(),
+      key_slice, &value);
+
+  // trigger java unref on key.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+
+  if (s.IsNotFound()) {
+    return nullptr;
+  }
+
+  if (s.ok()) {
+    jbyteArray jvalue = env->NewByteArray(value.size());
+    env->SetByteArrayRegion(
+        jvalue, 0, value.size(),
+        reinterpret_cast<const jbyte*>(value.c_str()));
+    return jvalue;
+  }
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+
+  return nullptr;
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    get
+ * Signature: (J[BI[BI)I
+ */
+jint Java_org_rocksdb_RocksDB_get__J_3BI_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  static const int kNotFound = -1;
+  static const int kStatusError = -2;
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+
+  jbyte* key = env->GetByteArrayElements(jkey, 0);
+  rocksdb::Slice key_slice(
+      reinterpret_cast<char*>(key), jkey_len);
+
+  // TODO(yhchiang): we might save one memory allocation here by adding
+  // a DB::Get() function which takes preallocated jbyte* as input.
+  std::string cvalue;
+  rocksdb::Status s = db->Get(
+      rocksdb::ReadOptions(), key_slice, &cvalue);
+
+  // trigger java unref on key.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+
+  if (s.IsNotFound()) {
+    return kNotFound;
+  } else if (!s.ok()) {
+    // Here since we are throwing a Java exception from c++ side.
+    // As a result, c++ does not know calling this function will in fact
+    // throwing an exception.  As a result, the execution flow will
+    // not stop here, and codes after this throw will still be
+    // executed.
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+
+    // Return a dummy const value to avoid compilation error, although
+    // java side might not have a chance to get the return value :)
+    return kStatusError;
+  }
+
+  int cvalue_len = static_cast<int>(cvalue.size());
+  int length = std::min(jvalue_len, cvalue_len);
+
+  env->SetByteArrayRegion(
+      jvalue, 0, length,
+      reinterpret_cast<const jbyte*>(cvalue.c_str()));
+  return cvalue_len;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Delete()
+void rocksdb_remove_helper(
+    JNIEnv* env, rocksdb::DB* db, const rocksdb::WriteOptions& write_options,
+    jbyteArray jkey, jint jkey_len) {
+  jbyte* key = env->GetByteArrayElements(jkey, 0);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+
+  rocksdb::Status s = db->Delete(write_options, key_slice);
+
+  // trigger java unref on key and value.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+
+  if (!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+  return;
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    remove
+ * Signature: (J[BI)V
+ */
+void Java_org_rocksdb_RocksDB_remove__J_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  static const rocksdb::WriteOptions default_write_options =
+      rocksdb::WriteOptions();
+
+  rocksdb_remove_helper(env, db, default_write_options, jkey, jkey_len);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    remove
+ * Signature: (JJ[BI)V
+ */
+void Java_org_rocksdb_RocksDB_remove__JJ_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jlong jwrite_options, jbyteArray jkey, jint jkey_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  auto write_options = reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options);
+
+  rocksdb_remove_helper(env, db, *write_options, jkey, jkey_len);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::~DB()
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    close0
+ * Signature: ()V
+ */
+void Java_org_rocksdb_RocksDB_close0(
+    JNIEnv* env, jobject java_db) {
+  rocksdb::DB* db = rocksdb::RocksDBJni::getHandle(env, java_db);
+  assert(db != nullptr);
+  delete db;
+
+  rocksdb::RocksDBJni::setHandle(env, java_db, nullptr);
+}
@@ -0,0 +1,263 @@
+// Copyright (c) 2014, 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 file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::WriteBatch methods from Java side.
+#include <memory>
+
+#include "include/org_rocksdb_WriteBatch.h"
+#include "include/org_rocksdb_WriteBatchInternal.h"
+#include "include/org_rocksdb_WriteBatchTest.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/db.h"
+#include "db/memtable.h"
+#include "rocksdb/write_batch.h"
+#include "db/write_batch_internal.h"
+#include "rocksdb/env.h"
+#include "rocksdb/memtablerep.h"
+#include "util/logging.h"
+#include "util/testharness.h"
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    newWriteBatch
+ * Signature: (I)V
+ */
+void Java_org_rocksdb_WriteBatch_newWriteBatch(
+    JNIEnv* env, jobject jobj, jint jreserved_bytes) {
+  rocksdb::WriteBatch* wb = new rocksdb::WriteBatch(
+      static_cast<size_t>(jreserved_bytes));
+
+  rocksdb::WriteBatchJni::setHandle(env, jobj, wb);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    count
+ * Signature: ()I
+ */
+jint Java_org_rocksdb_WriteBatch_count(JNIEnv* env, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  return static_cast<jint>(wb->Count());
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    clear
+ * Signature: ()V
+ */
+void Java_org_rocksdb_WriteBatch_clear(JNIEnv* env, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  wb->Clear();
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    put
+ * Signature: ([BI[BI)V
+ */
+void Java_org_rocksdb_WriteBatch_put(
+    JNIEnv* env, jobject jobj,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* key = env->GetByteArrayElements(jkey, nullptr);
+  jbyte* value = env->GetByteArrayElements(jvalue, nullptr);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  rocksdb::Slice value_slice(reinterpret_cast<char*>(value), jvalue_len);
+  wb->Put(key_slice, value_slice);
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+  env->ReleaseByteArrayElements(jvalue, value, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    merge
+ * Signature: ([BI[BI)V
+ */
+JNIEXPORT void JNICALL Java_org_rocksdb_WriteBatch_merge(
+    JNIEnv* env, jobject jobj,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* key = env->GetByteArrayElements(jkey, nullptr);
+  jbyte* value = env->GetByteArrayElements(jvalue, nullptr);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  rocksdb::Slice value_slice(reinterpret_cast<char*>(value), jvalue_len);
+  wb->Merge(key_slice, value_slice);
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+  env->ReleaseByteArrayElements(jvalue, value, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    remove
+ * Signature: ([BI)V
+ */
+JNIEXPORT void JNICALL Java_org_rocksdb_WriteBatch_remove(
+    JNIEnv* env, jobject jobj,
+    jbyteArray jkey, jint jkey_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* key = env->GetByteArrayElements(jkey, nullptr);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  wb->Delete(key_slice);
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    putLogData
+ * Signature: ([BI)V
+ */
+void Java_org_rocksdb_WriteBatch_putLogData(
+    JNIEnv* env, jobject jobj, jbyteArray jblob, jint jblob_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* blob = env->GetByteArrayElements(jblob, nullptr);
+  rocksdb::Slice blob_slice(reinterpret_cast<char*>(blob), jblob_len);
+  wb->PutLogData(blob_slice);
+  env->ReleaseByteArrayElements(jblob, blob, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    dispose0
+ * Signature: ()V
+ */
+void Java_org_rocksdb_WriteBatch_dispose0(JNIEnv* env, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+  delete wb;
+
+  rocksdb::WriteBatchJni::setHandle(env, jobj, nullptr);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchInternal
+ * Method:    setSequence
+ * Signature: (Lorg/rocksdb/WriteBatch;J)V
+ */
+void Java_org_rocksdb_WriteBatchInternal_setSequence(
+    JNIEnv* env, jclass jclazz, jobject jobj, jlong jsn) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  rocksdb::WriteBatchInternal::SetSequence(
+      wb, static_cast<rocksdb::SequenceNumber>(jsn));
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchInternal
+ * Method:    sequence
+ * Signature: (Lorg/rocksdb/WriteBatch;)J
+ */
+jlong Java_org_rocksdb_WriteBatchInternal_sequence(
+    JNIEnv* env, jclass jclazz, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  return static_cast<jlong>(rocksdb::WriteBatchInternal::Sequence(wb));
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchInternal
+ * Method:    append
+ * Signature: (Lorg/rocksdb/WriteBatch;Lorg/rocksdb/WriteBatch;)V
+ */
+void Java_org_rocksdb_WriteBatchInternal_append(
+    JNIEnv* env, jclass jclazz, jobject jwb1, jobject jwb2) {
+  rocksdb::WriteBatch* wb1 = rocksdb::WriteBatchJni::getHandle(env, jwb1);
+  assert(wb1 != nullptr);
+  rocksdb::WriteBatch* wb2 = rocksdb::WriteBatchJni::getHandle(env, jwb2);
+  assert(wb2 != nullptr);
+
+  rocksdb::WriteBatchInternal::Append(wb1, wb2);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchTest
+ * Method:    getContents
+ * Signature: (Lorg/rocksdb/WriteBatch;)[B
+ */
+jbyteArray Java_org_rocksdb_WriteBatchTest_getContents(
+    JNIEnv* env, jclass jclazz, jobject jobj) {
+  rocksdb::WriteBatch* b = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(b != nullptr);
+
+  // todo: Currently the following code is directly copied from
+  // db/write_bench_test.cc.  It could be implemented in java once
+  // all the necessary components can be accessed via jni api.
+
+  rocksdb::InternalKeyComparator cmp(rocksdb::BytewiseComparator());
+  auto factory = std::make_shared<rocksdb::SkipListFactory>();
+  rocksdb::Options options;
+  options.memtable_factory = factory;
+  rocksdb::MemTable* mem = new rocksdb::MemTable(cmp, options);
+  mem->Ref();
+  std::string state;
+  rocksdb::Status s = rocksdb::WriteBatchInternal::InsertInto(b, mem, &options);
+  int count = 0;
+  rocksdb::Iterator* iter = mem->NewIterator();
+  for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+    rocksdb::ParsedInternalKey ikey;
+    memset(reinterpret_cast<void*>(&ikey), 0, sizeof(ikey));
+    ASSERT_TRUE(rocksdb::ParseInternalKey(iter->key(), &ikey));
+    switch (ikey.type) {
+      case rocksdb::kTypeValue:
+        state.append("Put(");
+        state.append(ikey.user_key.ToString());
+        state.append(", ");
+        state.append(iter->value().ToString());
+        state.append(")");
+        count++;
+        break;
+      case rocksdb::kTypeMerge:
+        state.append("Merge(");
+        state.append(ikey.user_key.ToString());
+        state.append(", ");
+        state.append(iter->value().ToString());
+        state.append(")");
+        count++;
+        break;
+      case rocksdb::kTypeDeletion:
+        state.append("Delete(");
+        state.append(ikey.user_key.ToString());
+        state.append(")");
+        count++;
+        break;
+      default:
+        assert(false);
+        break;
+    }
+    state.append("@");
+    state.append(rocksdb::NumberToString(ikey.sequence));
+  }
+  delete iter;
+  if (!s.ok()) {
+    state.append(s.ToString());
+  } else if (count != rocksdb::WriteBatchInternal::Count(b)) {
+    state.append("CountMismatch()");
+  }
+  delete mem->Unref();
+
+  jbyteArray jstate = env->NewByteArray(state.size());
+  env->SetByteArrayRegion(
+      jstate, 0, state.size(),
+      reinterpret_cast<const jbyte*>(state.c_str()));
+
+  return jstate;
+}
+
@@ -13,6 +13,7 @@ phutil_register_library_map(array(
    'FacebookFbcodeLintEngine' => 'lint_engine/FacebookFbcodeLintEngine.php',
    'FbcodeCppLinter' => 'cpp_linter/FbcodeCppLinter.php',
    'PfffCppLinter' => 'cpp_linter/PfffCppLinter.php',
+    'ArcanistCpplintLinter' => 'cpp_linter/ArcanistCpplintLinter.php',
  ),
  'function' =>
  array(
@@ -0,0 +1,88 @@
+<?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()."/../..";
+  }
+}
--- a/Show More
+++ b/Show More