Compile MemEnv with standard RocksDB library

Summary: This was a feature request by osquery. See task t5617758

Test Plan: compiles and memenv_test runs

Reviewers: yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32115

HISTORY.md

@@ -11,6 +11,7 @@
 * Added BlockBasedTableOptions.format_version option, which allows user to specify which version of block based table he wants. As a general guidline, newer versions have more features, but might not be readable by older versions of RocksDB.
 * Added new block based table format (version 2), which you can enable by setting BlockBasedTableOptions.format_version = 2. This format changes how we encode size information in compressed blocks and should help with memory allocations if you're using Zlib or BZip2 compressions.
 * GetThreadStatus() is now able to report compaction activity.
+* MemEnv (env that stores data in memory) is now available in default library build. You can create it by calling NewMemEnv().
 
 ### Public API changes
 * Deprecated skip_log_error_on_recovery option

Makefile

@@ -99,7 +99,6 @@ CXXFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverl
 LDFLAGS += $(PLATFORM_LDFLAGS)
 
 LIBOBJECTS = $(SOURCES:.cc=.o)
-MEMENVOBJECTS = $(MEMENV_SOURCES:.cc=.o)
 MOCKOBJECTS = $(MOCK_SOURCES:.cc=.o)
 
 TESTUTIL = ./util/testutil.o
@@ -196,7 +195,6 @@ ifeq ($(LIBNAME),)
         LIBNAME=librocksdb
 endif
 LIBRARY = ${LIBNAME}.a
-MEMENVLIBRARY = libmemenv.a
 
 ROCKSDB_MAJOR = $(shell egrep "ROCKSDB_MAJOR.[0-9]" include/rocksdb/version.h | cut -d ' ' -f 3)
 ROCKSDB_MINOR = $(shell egrep "ROCKSDB_MINOR.[0-9]" include/rocksdb/version.h | cut -d ' ' -f 3)
@@ -311,7 +309,7 @@ unity: unity.cc unity.o
 	$(CXX) unity.o $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
 
 clean:
-	-rm -f $(PROGRAMS) $(TESTS) $(LIBRARY) $(SHARED) $(MEMENVLIBRARY) make_config.mk unity.cc
+	-rm -f $(PROGRAMS) $(TESTS) $(LIBRARY) $(SHARED) make_config.mk unity.cc
 	-rm -rf ios-x86/* ios-arm/*
 	-find . -name "*.[oda]" -exec rm {} \;
 	-find . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm {} \;
@@ -552,12 +550,8 @@ options_test: util/options_test.o util/options_helper.o $(LIBOBJECTS) $(TESTHARN
 sst_dump_test: util/sst_dump_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/sst_dump_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@  $(LDFLAGS) $(COVERAGEFLAGS)
 
-$(MEMENVLIBRARY) : $(MEMENVOBJECTS)
-	rm -f $@
-	$(AR) -rs $@ $(MEMENVOBJECTS)
-
-memenv_test : helpers/memenv/memenv_test.o $(MEMENVOBJECTS) $(LIBOBJECTS) $(TESTHARNESS)
-	$(CXX) helpers/memenv/memenv_test.o $(MEMENVOBJECTS) $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+memenv_test : util/memenv_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) util/memenv_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
 
 mock_env_test : util/mock_env_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/mock_env_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)

build_tools/build_detect_platform

@@ -161,7 +161,7 @@ if test -z "$DO_NOT_RUN_BUILD_DETECT_VERSION"; then
   "$PWD/build_tools/build_detect_version"
 fi
 
-# We want to make a list of all cc files within util, db, table, and helpers
+# We want to make a list of all cc files within util, db and table
 # except for the test and benchmark files. By default, find will output a list
 # of all files matching either rule, so we need to append -print to make the
 # prune take effect.
@@ -179,7 +179,6 @@ set +f # re-enable globbing
 # file.
 echo "SOURCES=$PORTABLE_FILES $GENERIC_PORT_FILES $PORT_FILES" >> "$OUTPUT"
 echo "MOCK_SOURCES=$MOCK_SOURCES" >> "$OUTPUT"
-echo "MEMENV_SOURCES=helpers/memenv/memenv.cc" >> "$OUTPUT"
 
 if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
     # Cross-compiling; do not try any compilation tests.

build_tools/unity

@@ -54,7 +54,7 @@ case "$TARGET_OS" in
         exit 1
 esac
 
-# We want to make a list of all cc files within util, db, table, and helpers
+# We want to make a list of all cc files within util, db and table
 # except for the test and benchmark files. By default, find will output a list
 # of all files matching either rule, so we need to append -print to make the
 # prune take effect.

util/memenv.cc

@@ -13,6 +13,8 @@
 
 namespace rocksdb {
 
+#ifndef ROCKSDB_LITE
+
 namespace {
 
 std::string NormalizeFileName(const std::string fname) {
@@ -420,4 +422,10 @@ Env* NewMemEnv(Env* base_env) {
   return new InMemoryEnv(base_env);
 }
 
+#else  // ROCKSDB_LITE
+
+Env* NewMemEnv(Env* base_env) { return nullptr; }
+
+#endif  // !ROCKSDB_LITE
+
 }  // namespace rocksdb