Extract benchmark from db_test.cc.

The benchmark in db/db_test.cc is extracted to its own file,
benchmarks/db_bench_log.cc.

PiperOrigin-RevId: 418713499

3 files changed, 99 insertions, 71 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f8285b8..7690302 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -298,11 +298,6 @@ if(LEVELDB_BUILD_TESTS)
   # This project is tested using GoogleTest.
   add_subdirectory("third_party/googletest")
 
-  # This project uses Google benchmark for benchmarking.
-  set(BENCHMARK_ENABLE_TESTING OFF CACHE BOOL "" FORCE)
-  set(BENCHMARK_ENABLE_EXCEPTIONS OFF CACHE BOOL "" FORCE)
-  add_subdirectory("third_party/benchmark")
-
   # GoogleTest triggers a missing field initializers warning.
   if(LEVELDB_HAVE_NO_MISSING_FIELD_INITIALIZERS)
     set_property(TARGET gtest
@@ -323,7 +318,7 @@ if(LEVELDB_BUILD_TESTS)
 
         "${test_file}"
     )
-    target_link_libraries("${test_target_name}" leveldb gmock gtest benchmark)
+    target_link_libraries("${test_target_name}" leveldb gmock gtest)
     target_compile_definitions("${test_target_name}"
       PRIVATE
         ${LEVELDB_PLATFORM_NAME}=1
@@ -386,6 +381,11 @@ if(LEVELDB_BUILD_TESTS)
 endif(LEVELDB_BUILD_TESTS)
 
 if(LEVELDB_BUILD_BENCHMARKS)
+  # This project uses Google benchmark for benchmarking.
+  set(BENCHMARK_ENABLE_TESTING OFF CACHE BOOL "" FORCE)
+  set(BENCHMARK_ENABLE_EXCEPTIONS OFF CACHE BOOL "" FORCE)
+  add_subdirectory("third_party/benchmark")
+
   function(leveldb_benchmark bench_file)
     get_filename_component(bench_target_name "${bench_file}" NAME_WE)
 
@@ -400,7 +400,7 @@ if(LEVELDB_BUILD_BENCHMARKS)
 
         "${bench_file}"
     )
-    target_link_libraries("${bench_target_name}" leveldb gmock gtest)
+    target_link_libraries("${bench_target_name}" leveldb gmock gtest benchmark)
     target_compile_definitions("${bench_target_name}"
       PRIVATE
         ${LEVELDB_PLATFORM_NAME}=1
diff --git a/benchmarks/db_bench_log.cc b/benchmarks/db_bench_log.cc
new file mode 100644
index 0000000..a1845bf
--- /dev/null
+++ b/benchmarks/db_bench_log.cc
@@ -0,0 +1,92 @@
+// Copyright (c) 2019 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 <cinttypes>
+#include <cstdio>
+#include <string>
+
+#include "gtest/gtest.h"
+#include "benchmark/benchmark.h"
+#include "db/version_set.h"
+#include "leveldb/comparator.h"
+#include "leveldb/db.h"
+#include "leveldb/env.h"
+#include "leveldb/options.h"
+#include "port/port.h"
+#include "util/mutexlock.h"
+#include "util/testutil.h"
+
+namespace leveldb {
+
+namespace {
+
+std::string MakeKey(unsigned int num) {
+  char buf[30];
+  std::snprintf(buf, sizeof(buf), "%016u", num);
+  return std::string(buf);
+}
+
+void BM_LogAndApply(benchmark::State& state) {
+  const int num_base_files = state.range(0);
+
+  std::string dbname = testing::TempDir() + "leveldb_test_benchmark";
+  DestroyDB(dbname, Options());
+
+  DB* db = nullptr;
+  Options opts;
+  opts.create_if_missing = true;
+  Status s = DB::Open(opts, dbname, &db);
+  ASSERT_LEVELDB_OK(s);
+  ASSERT_TRUE(db != nullptr);
+
+  delete db;
+  db = nullptr;
+
+  Env* env = Env::Default();
+
+  port::Mutex mu;
+  MutexLock l(&mu);
+
+  InternalKeyComparator cmp(BytewiseComparator());
+  Options options;
+  VersionSet vset(dbname, &options, nullptr, &cmp);
+  bool save_manifest;
+  ASSERT_LEVELDB_OK(vset.Recover(&save_manifest));
+  VersionEdit vbase;
+  uint64_t fnum = 1;
+  for (int i = 0; i < num_base_files; i++) {
+    InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
+    InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
+    vbase.AddFile(2, fnum++, 1 /* file size */, start, limit);
+  }
+  ASSERT_LEVELDB_OK(vset.LogAndApply(&vbase, &mu));
+
+  uint64_t start_micros = env->NowMicros();
+
+  for (auto st : state) {
+    VersionEdit vedit;
+    vedit.RemoveFile(2, fnum);
+    InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
+    InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
+    vedit.AddFile(2, fnum++, 1 /* file size */, start, limit);
+    vset.LogAndApply(&vedit, &mu);
+  }
+
+  uint64_t stop_micros = env->NowMicros();
+  unsigned int us = stop_micros - start_micros;
+  char buf[16];
+  std::snprintf(buf, sizeof(buf), "%d", num_base_files);
+  std::fprintf(stderr,
+               "BM_LogAndApply/%-6s   %8" PRIu64
+               " iters : %9u us (%7.0f us / iter)\n",
+               buf, state.iterations(), us, ((float)us) / state.iterations());
+}
+
+BENCHMARK(BM_LogAndApply)->Arg(1)->Arg(100)->Arg(10000)->Arg(100000);
+
+}  // namespace
+
+}  // namespace leveldb
+
+BENCHMARK_MAIN();
diff --git a/db/db_test.cc b/db/db_test.cc
index 908b41d..7f22688 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -9,7 +9,6 @@
 #include <string>
 
 #include "gtest/gtest.h"
-#include "benchmark/benchmark.h"
 #include "db/db_impl.h"
 #include "db/filename.h"
 #include "db/version_set.h"
@@ -2295,72 +2294,9 @@ TEST_F(DBTest, Randomized) {
   } while (ChangeOptions());
 }
 
-std::string MakeKey(unsigned int num) {
-  char buf[30];
-  std::snprintf(buf, sizeof(buf), "%016u", num);
-  return std::string(buf);
-}
-
-static void BM_LogAndApply(benchmark::State& state) {
-  const int num_base_files = state.range(0);
-
-  std::string dbname = testing::TempDir() + "leveldb_test_benchmark";
-  DestroyDB(dbname, Options());
-
-  DB* db = nullptr;
-  Options opts;
-  opts.create_if_missing = true;
-  Status s = DB::Open(opts, dbname, &db);
-  ASSERT_LEVELDB_OK(s);
-  ASSERT_TRUE(db != nullptr);
-
-  delete db;
-  db = nullptr;
-
-  Env* env = Env::Default();
-
-  port::Mutex mu;
-  MutexLock l(&mu);
-
-  InternalKeyComparator cmp(BytewiseComparator());
-  Options options;
-  VersionSet vset(dbname, &options, nullptr, &cmp);
-  bool save_manifest;
-  ASSERT_LEVELDB_OK(vset.Recover(&save_manifest));
-  VersionEdit vbase;
-  uint64_t fnum = 1;
-  for (int i = 0; i < num_base_files; i++) {
-    InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
-    InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
-    vbase.AddFile(2, fnum++, 1 /* file size */, start, limit);
-  }
-  ASSERT_LEVELDB_OK(vset.LogAndApply(&vbase, &mu));
-
-  uint64_t start_micros = env->NowMicros();
-
-  for (auto st : state) {
-    VersionEdit vedit;
-    vedit.RemoveFile(2, fnum);
-    InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
-    InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
-    vedit.AddFile(2, fnum++, 1 /* file size */, start, limit);
-    vset.LogAndApply(&vedit, &mu);
-  }
-  uint64_t stop_micros = env->NowMicros();
-  unsigned int us = stop_micros - start_micros;
-  char buf[16];
-  std::snprintf(buf, sizeof(buf), "%d", num_base_files);
-  std::fprintf(stderr,
-               "BM_LogAndApply/%-6s   %8" PRIu64
-               " iters : %9u us (%7.0f us / iter)\n",
-               buf, state.iterations(), us, ((float)us) / state.iterations());
-}
-
-BENCHMARK(BM_LogAndApply)->Arg(1)->Arg(100)->Arg(10000)->Arg(100000);
 }  // namespace leveldb
 
 int main(int argc, char** argv) {
   testing::InitGoogleTest(&argc, argv);
-  benchmark::RunSpecifiedBenchmarks();
   return RUN_ALL_TESTS();
 }