Consolidate benchmark code to benchmarks/.

Currently, the benchmark used to assess leveldb changes lives in db/. The codebase also contains two benchmarks against other database engines in doc/bench/. Moving all the benchmarks in one place opens up the way for extracting common code.

PiperOrigin-RevId: 246737541

3 files changed, 3 insertions, 1239 deletions

diff --git a/doc/bench/db_bench_sqlite3.cc b/doc/bench/db_bench_sqlite3.cc
deleted file mode 100644
index f183f4f..0000000
--- a/doc/bench/db_bench_sqlite3.cc
+++ /dev/null
@@ -1,714 +0,0 @@
-// 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 <sqlite3.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "util/histogram.h"
-#include "util/random.h"
-#include "util/testutil.h"
-
-// Comma-separated list of operations to run in the specified order
-//   Actual benchmarks:
-//
-//   fillseq       -- write N values in sequential key order in async mode
-//   fillseqsync   -- write N/100 values in sequential key order in sync mode
-//   fillseqbatch  -- batch write N values in sequential key order in async mode
-//   fillrandom    -- write N values in random key order in async mode
-//   fillrandsync  -- write N/100 values in random key order in sync mode
-//   fillrandbatch -- batch write N values in sequential key order in async mode
-//   overwrite     -- overwrite N values in random key order in async mode
-//   fillrand100K  -- write N/1000 100K values in random order in async mode
-//   fillseq100K   -- write N/1000 100K values in sequential order in async mode
-//   readseq       -- read N times sequentially
-//   readrandom    -- read N times in random order
-//   readrand100K  -- read N/1000 100K values in sequential order in async mode
-static const char* FLAGS_benchmarks =
-    "fillseq,"
-    "fillseqsync,"
-    "fillseqbatch,"
-    "fillrandom,"
-    "fillrandsync,"
-    "fillrandbatch,"
-    "overwrite,"
-    "overwritebatch,"
-    "readrandom,"
-    "readseq,"
-    "fillrand100K,"
-    "fillseq100K,"
-    "readseq,"
-    "readrand100K,";
-
-// Number of key/values to place in database
-static int FLAGS_num = 1000000;
-
-// Number of read operations to do.  If negative, do FLAGS_num reads.
-static int FLAGS_reads = -1;
-
-// Size of each value
-static int FLAGS_value_size = 100;
-
-// Print histogram of operation timings
-static bool FLAGS_histogram = false;
-
-// Arrange to generate values that shrink to this fraction of
-// their original size after compression
-static double FLAGS_compression_ratio = 0.5;
-
-// Page size. Default 1 KB.
-static int FLAGS_page_size = 1024;
-
-// Number of pages.
-// Default cache size = FLAGS_page_size * FLAGS_num_pages = 4 MB.
-static int FLAGS_num_pages = 4096;
-
-// If true, do not destroy the existing database.  If you set this
-// flag and also specify a benchmark that wants a fresh database, that
-// benchmark will fail.
-static bool FLAGS_use_existing_db = false;
-
-// If true, we allow batch writes to occur
-static bool FLAGS_transaction = true;
-
-// If true, we enable Write-Ahead Logging
-static bool FLAGS_WAL_enabled = true;
-
-// Use the db with the following name.
-static const char* FLAGS_db = nullptr;
-
-inline static void ExecErrorCheck(int status, char* err_msg) {
-  if (status != SQLITE_OK) {
-    fprintf(stderr, "SQL error: %s\n", err_msg);
-    sqlite3_free(err_msg);
-    exit(1);
-  }
-}
-
-inline static void StepErrorCheck(int status) {
-  if (status != SQLITE_DONE) {
-    fprintf(stderr, "SQL step error: status = %d\n", status);
-    exit(1);
-  }
-}
-
-inline static void ErrorCheck(int status) {
-  if (status != SQLITE_OK) {
-    fprintf(stderr, "sqlite3 error: status = %d\n", status);
-    exit(1);
-  }
-}
-
-inline static void WalCheckpoint(sqlite3* db_) {
-  // Flush all writes to disk
-  if (FLAGS_WAL_enabled) {
-    sqlite3_wal_checkpoint_v2(db_, nullptr, SQLITE_CHECKPOINT_FULL, nullptr,
-                              nullptr);
-  }
-}
-
-namespace leveldb {
-
-// Helper for quickly generating random data.
-namespace {
-class RandomGenerator {
- private:
-  std::string data_;
-  int pos_;
-
- public:
-  RandomGenerator() {
-    // We use a limited amount of data over and over again and ensure
-    // that it is larger than the compression window (32KB), and also
-    // large enough to serve all typical value sizes we want to write.
-    Random rnd(301);
-    std::string piece;
-    while (data_.size() < 1048576) {
-      // Add a short fragment that is as compressible as specified
-      // by FLAGS_compression_ratio.
-      test::CompressibleString(&rnd, FLAGS_compression_ratio, 100, &piece);
-      data_.append(piece);
-    }
-    pos_ = 0;
-  }
-
-  Slice Generate(int len) {
-    if (pos_ + len > data_.size()) {
-      pos_ = 0;
-      assert(len < data_.size());
-    }
-    pos_ += len;
-    return Slice(data_.data() + pos_ - len, len);
-  }
-};
-
-static Slice TrimSpace(Slice s) {
-  int start = 0;
-  while (start < s.size() && isspace(s[start])) {
-    start++;
-  }
-  int limit = s.size();
-  while (limit > start && isspace(s[limit - 1])) {
-    limit--;
-  }
-  return Slice(s.data() + start, limit - start);
-}
-
-}  // namespace
-
-class Benchmark {
- private:
-  sqlite3* db_;
-  int db_num_;
-  int num_;
-  int reads_;
-  double start_;
-  double last_op_finish_;
-  int64_t bytes_;
-  std::string message_;
-  Histogram hist_;
-  RandomGenerator gen_;
-  Random rand_;
-
-  // State kept for progress messages
-  int done_;
-  int next_report_;  // When to report next
-
-  void PrintHeader() {
-    const int kKeySize = 16;
-    PrintEnvironment();
-    fprintf(stdout, "Keys:       %d bytes each\n", kKeySize);
-    fprintf(stdout, "Values:     %d bytes each\n", FLAGS_value_size);
-    fprintf(stdout, "Entries:    %d\n", num_);
-    fprintf(stdout, "RawSize:    %.1f MB (estimated)\n",
-            ((static_cast<int64_t>(kKeySize + FLAGS_value_size) * num_) /
-             1048576.0));
-    PrintWarnings();
-    fprintf(stdout, "------------------------------------------------\n");
-  }
-
-  void PrintWarnings() {
-#if defined(__GNUC__) && !defined(__OPTIMIZE__)
-    fprintf(
-        stdout,
-        "WARNING: Optimization is disabled: benchmarks unnecessarily slow\n");
-#endif
-#ifndef NDEBUG
-    fprintf(stdout,
-            "WARNING: Assertions are enabled; benchmarks unnecessarily slow\n");
-#endif
-  }
-
-  void PrintEnvironment() {
-    fprintf(stderr, "SQLite:     version %s\n", SQLITE_VERSION);
-
-#if defined(__linux)
-    time_t now = time(nullptr);
-    fprintf(stderr, "Date:       %s", ctime(&now));  // ctime() adds newline
-
-    FILE* cpuinfo = fopen("/proc/cpuinfo", "r");
-    if (cpuinfo != nullptr) {
-      char line[1000];
-      int num_cpus = 0;
-      std::string cpu_type;
-      std::string cache_size;
-      while (fgets(line, sizeof(line), cpuinfo) != nullptr) {
-        const char* sep = strchr(line, ':');
-        if (sep == nullptr) {
-          continue;
-        }
-        Slice key = TrimSpace(Slice(line, sep - 1 - line));
-        Slice val = TrimSpace(Slice(sep + 1));
-        if (key == "model name") {
-          ++num_cpus;
-          cpu_type = val.ToString();
-        } else if (key == "cache size") {
-          cache_size = val.ToString();
-        }
-      }
-      fclose(cpuinfo);
-      fprintf(stderr, "CPU:        %d * %s\n", num_cpus, cpu_type.c_str());
-      fprintf(stderr, "CPUCache:   %s\n", cache_size.c_str());
-    }
-#endif
-  }
-
-  void Start() {
-    start_ = Env::Default()->NowMicros() * 1e-6;
-    bytes_ = 0;
-    message_.clear();
-    last_op_finish_ = start_;
-    hist_.Clear();
-    done_ = 0;
-    next_report_ = 100;
-  }
-
-  void FinishedSingleOp() {
-    if (FLAGS_histogram) {
-      double now = Env::Default()->NowMicros() * 1e-6;
-      double micros = (now - last_op_finish_) * 1e6;
-      hist_.Add(micros);
-      if (micros > 20000) {
-        fprintf(stderr, "long op: %.1f micros%30s\r", micros, "");
-        fflush(stderr);
-      }
-      last_op_finish_ = now;
-    }
-
-    done_++;
-    if (done_ >= next_report_) {
-      if (next_report_ < 1000)
-        next_report_ += 100;
-      else if (next_report_ < 5000)
-        next_report_ += 500;
-      else if (next_report_ < 10000)
-        next_report_ += 1000;
-      else if (next_report_ < 50000)
-        next_report_ += 5000;
-      else if (next_report_ < 100000)
-        next_report_ += 10000;
-      else if (next_report_ < 500000)
-        next_report_ += 50000;
-      else
-        next_report_ += 100000;
-      fprintf(stderr, "... finished %d ops%30s\r", done_, "");
-      fflush(stderr);
-    }
-  }
-
-  void Stop(const Slice& name) {
-    double finish = Env::Default()->NowMicros() * 1e-6;
-
-    // Pretend at least one op was done in case we are running a benchmark
-    // that does not call FinishedSingleOp().
-    if (done_ < 1) done_ = 1;
-
-    if (bytes_ > 0) {
-      char rate[100];
-      snprintf(rate, sizeof(rate), "%6.1f MB/s",
-               (bytes_ / 1048576.0) / (finish - start_));
-      if (!message_.empty()) {
-        message_ = std::string(rate) + " " + message_;
-      } else {
-        message_ = rate;
-      }
-    }
-
-    fprintf(stdout, "%-12s : %11.3f micros/op;%s%s\n", name.ToString().c_str(),
-            (finish - start_) * 1e6 / done_, (message_.empty() ? "" : " "),
-            message_.c_str());
-    if (FLAGS_histogram) {
-      fprintf(stdout, "Microseconds per op:\n%s\n", hist_.ToString().c_str());
-    }
-    fflush(stdout);
-  }
-
- public:
-  enum Order { SEQUENTIAL, RANDOM };
-  enum DBState { FRESH, EXISTING };
-
-  Benchmark()
-      : db_(nullptr),
-        db_num_(0),
-        num_(FLAGS_num),
-        reads_(FLAGS_reads < 0 ? FLAGS_num : FLAGS_reads),
-        bytes_(0),
-        rand_(301) {
-    std::vector<std::string> files;
-    std::string test_dir;
-    Env::Default()->GetTestDirectory(&test_dir);
-    Env::Default()->GetChildren(test_dir, &files);
-    if (!FLAGS_use_existing_db) {
-      for (int i = 0; i < files.size(); i++) {
-        if (Slice(files[i]).starts_with("dbbench_sqlite3")) {
-          std::string file_name(test_dir);
-          file_name += "/";
-          file_name += files[i];
-          Env::Default()->DeleteFile(file_name.c_str());
-        }
-      }
-    }
-  }
-
-  ~Benchmark() {
-    int status = sqlite3_close(db_);
-    ErrorCheck(status);
-  }
-
-  void Run() {
-    PrintHeader();
-    Open();
-
-    const char* benchmarks = FLAGS_benchmarks;
-    while (benchmarks != nullptr) {
-      const char* sep = strchr(benchmarks, ',');
-      Slice name;
-      if (sep == nullptr) {
-        name = benchmarks;
-        benchmarks = nullptr;
-      } else {
-        name = Slice(benchmarks, sep - benchmarks);
-        benchmarks = sep + 1;
-      }
-
-      bytes_ = 0;
-      Start();
-
-      bool known = true;
-      bool write_sync = false;
-      if (name == Slice("fillseq")) {
-        Write(write_sync, SEQUENTIAL, FRESH, num_, FLAGS_value_size, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillseqbatch")) {
-        Write(write_sync, SEQUENTIAL, FRESH, num_, FLAGS_value_size, 1000);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillrandom")) {
-        Write(write_sync, RANDOM, FRESH, num_, FLAGS_value_size, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillrandbatch")) {
-        Write(write_sync, RANDOM, FRESH, num_, FLAGS_value_size, 1000);
-        WalCheckpoint(db_);
-      } else if (name == Slice("overwrite")) {
-        Write(write_sync, RANDOM, EXISTING, num_, FLAGS_value_size, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("overwritebatch")) {
-        Write(write_sync, RANDOM, EXISTING, num_, FLAGS_value_size, 1000);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillrandsync")) {
-        write_sync = true;
-        Write(write_sync, RANDOM, FRESH, num_ / 100, FLAGS_value_size, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillseqsync")) {
-        write_sync = true;
-        Write(write_sync, SEQUENTIAL, FRESH, num_ / 100, FLAGS_value_size, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillrand100K")) {
-        Write(write_sync, RANDOM, FRESH, num_ / 1000, 100 * 1000, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("fillseq100K")) {
-        Write(write_sync, SEQUENTIAL, FRESH, num_ / 1000, 100 * 1000, 1);
-        WalCheckpoint(db_);
-      } else if (name == Slice("readseq")) {
-        ReadSequential();
-      } else if (name == Slice("readrandom")) {
-        Read(RANDOM, 1);
-      } else if (name == Slice("readrand100K")) {
-        int n = reads_;
-        reads_ /= 1000;
-        Read(RANDOM, 1);
-        reads_ = n;
-      } else {
-        known = false;
-        if (name != Slice()) {  // No error message for empty name
-          fprintf(stderr, "unknown benchmark '%s'\n", name.ToString().c_str());
-        }
-      }
-      if (known) {
-        Stop(name);
-      }
-    }
-  }
-
-  void Open() {
-    assert(db_ == nullptr);
-
-    int status;
-    char file_name[100];
-    char* err_msg = nullptr;
-    db_num_++;
-
-    // Open database
-    std::string tmp_dir;
-    Env::Default()->GetTestDirectory(&tmp_dir);
-    snprintf(file_name, sizeof(file_name), "%s/dbbench_sqlite3-%d.db",
-             tmp_dir.c_str(), db_num_);
-    status = sqlite3_open(file_name, &db_);
-    if (status) {
-      fprintf(stderr, "open error: %s\n", sqlite3_errmsg(db_));
-      exit(1);
-    }
-
-    // Change SQLite cache size
-    char cache_size[100];
-    snprintf(cache_size, sizeof(cache_size), "PRAGMA cache_size = %d",
-             FLAGS_num_pages);
-    status = sqlite3_exec(db_, cache_size, nullptr, nullptr, &err_msg);
-    ExecErrorCheck(status, err_msg);
-
-    // FLAGS_page_size is defaulted to 1024
-    if (FLAGS_page_size != 1024) {
-      char page_size[100];
-      snprintf(page_size, sizeof(page_size), "PRAGMA page_size = %d",
-               FLAGS_page_size);
-      status = sqlite3_exec(db_, page_size, nullptr, nullptr, &err_msg);
-      ExecErrorCheck(status, err_msg);
-    }
-
-    // Change journal mode to WAL if WAL enabled flag is on
-    if (FLAGS_WAL_enabled) {
-      std::string WAL_stmt = "PRAGMA journal_mode = WAL";
-
-      // LevelDB's default cache size is a combined 4 MB
-      std::string WAL_checkpoint = "PRAGMA wal_autocheckpoint = 4096";
-      status = sqlite3_exec(db_, WAL_stmt.c_str(), nullptr, nullptr, &err_msg);
-      ExecErrorCheck(status, err_msg);
-      status =
-          sqlite3_exec(db_, WAL_checkpoint.c_str(), nullptr, nullptr, &err_msg);
-      ExecErrorCheck(status, err_msg);
-    }
-
-    // Change locking mode to exclusive and create tables/index for database
-    std::string locking_stmt = "PRAGMA locking_mode = EXCLUSIVE";
-    std::string create_stmt =
-        "CREATE TABLE test (key blob, value blob, PRIMARY KEY(key))";
-    std::string stmt_array[] = {locking_stmt, create_stmt};
-    int stmt_array_length = sizeof(stmt_array) / sizeof(std::string);
-    for (int i = 0; i < stmt_array_length; i++) {
-      status =
-          sqlite3_exec(db_, stmt_array[i].c_str(), nullptr, nullptr, &err_msg);
-      ExecErrorCheck(status, err_msg);
-    }
-  }
-
-  void Write(bool write_sync, Order order, DBState state, int num_entries,
-             int value_size, int entries_per_batch) {
-    // Create new database if state == FRESH
-    if (state == FRESH) {
-      if (FLAGS_use_existing_db) {
-        message_ = "skipping (--use_existing_db is true)";
-        return;
-      }
-      sqlite3_close(db_);
-      db_ = nullptr;
-      Open();
-      Start();
-    }
-
-    if (num_entries != num_) {
-      char msg[100];
-      snprintf(msg, sizeof(msg), "(%d ops)", num_entries);
-      message_ = msg;
-    }
-
-    char* err_msg = nullptr;
-    int status;
-
-    sqlite3_stmt *replace_stmt, *begin_trans_stmt, *end_trans_stmt;
-    std::string replace_str = "REPLACE INTO test (key, value) VALUES (?, ?)";
-    std::string begin_trans_str = "BEGIN TRANSACTION;";
-    std::string end_trans_str = "END TRANSACTION;";
-
-    // Check for synchronous flag in options
-    std::string sync_stmt =
-        (write_sync) ? "PRAGMA synchronous = FULL" : "PRAGMA synchronous = OFF";
-    status = sqlite3_exec(db_, sync_stmt.c_str(), nullptr, nullptr, &err_msg);
-    ExecErrorCheck(status, err_msg);
-
-    // Preparing sqlite3 statements
-    status = sqlite3_prepare_v2(db_, replace_str.c_str(), -1, &replace_stmt,
-                                nullptr);
-    ErrorCheck(status);
-    status = sqlite3_prepare_v2(db_, begin_trans_str.c_str(), -1,
-                                &begin_trans_stmt, nullptr);
-    ErrorCheck(status);
-    status = sqlite3_prepare_v2(db_, end_trans_str.c_str(), -1, &end_trans_stmt,
-                                nullptr);
-    ErrorCheck(status);
-
-    bool transaction = (entries_per_batch > 1);
-    for (int i = 0; i < num_entries; i += entries_per_batch) {
-      // Begin write transaction
-      if (FLAGS_transaction && transaction) {
-        status = sqlite3_step(begin_trans_stmt);
-        StepErrorCheck(status);
-        status = sqlite3_reset(begin_trans_stmt);
-        ErrorCheck(status);
-      }
-
-      // Create and execute SQL statements
-      for (int j = 0; j < entries_per_batch; j++) {
-        const char* value = gen_.Generate(value_size).data();
-
-        // Create values for key-value pair
-        const int k =
-            (order == SEQUENTIAL) ? i + j : (rand_.Next() % num_entries);
-        char key[100];
-        snprintf(key, sizeof(key), "%016d", k);
-
-        // Bind KV values into replace_stmt
-        status = sqlite3_bind_blob(replace_stmt, 1, key, 16, SQLITE_STATIC);
-        ErrorCheck(status);
-        status = sqlite3_bind_blob(replace_stmt, 2, value, value_size,
-                                   SQLITE_STATIC);
-        ErrorCheck(status);
-
-        // Execute replace_stmt
-        bytes_ += value_size + strlen(key);
-        status = sqlite3_step(replace_stmt);
-        StepErrorCheck(status);
-
-        // Reset SQLite statement for another use
-        status = sqlite3_clear_bindings(replace_stmt);
-        ErrorCheck(status);
-        status = sqlite3_reset(replace_stmt);
-        ErrorCheck(status);
-
-        FinishedSingleOp();
-      }
-
-      // End write transaction
-      if (FLAGS_transaction && transaction) {
-        status = sqlite3_step(end_trans_stmt);
-        StepErrorCheck(status);
-        status = sqlite3_reset(end_trans_stmt);
-        ErrorCheck(status);
-      }
-    }
-
-    status = sqlite3_finalize(replace_stmt);
-    ErrorCheck(status);
-    status = sqlite3_finalize(begin_trans_stmt);
-    ErrorCheck(status);
-    status = sqlite3_finalize(end_trans_stmt);
-    ErrorCheck(status);
-  }
-
-  void Read(Order order, int entries_per_batch) {
-    int status;
-    sqlite3_stmt *read_stmt, *begin_trans_stmt, *end_trans_stmt;
-
-    std::string read_str = "SELECT * FROM test WHERE key = ?";
-    std::string begin_trans_str = "BEGIN TRANSACTION;";
-    std::string end_trans_str = "END TRANSACTION;";
-
-    // Preparing sqlite3 statements
-    status = sqlite3_prepare_v2(db_, begin_trans_str.c_str(), -1,
-                                &begin_trans_stmt, nullptr);
-    ErrorCheck(status);
-    status = sqlite3_prepare_v2(db_, end_trans_str.c_str(), -1, &end_trans_stmt,
-                                nullptr);
-    ErrorCheck(status);
-    status = sqlite3_prepare_v2(db_, read_str.c_str(), -1, &read_stmt, nullptr);
-    ErrorCheck(status);
-
-    bool transaction = (entries_per_batch > 1);
-    for (int i = 0; i < reads_; i += entries_per_batch) {
-      // Begin read transaction
-      if (FLAGS_transaction && transaction) {
-        status = sqlite3_step(begin_trans_stmt);
-        StepErrorCheck(status);
-        status = sqlite3_reset(begin_trans_stmt);
-        ErrorCheck(status);
-      }
-
-      // Create and execute SQL statements
-      for (int j = 0; j < entries_per_batch; j++) {
-        // Create key value
-        char key[100];
-        int k = (order == SEQUENTIAL) ? i + j : (rand_.Next() % reads_);
-        snprintf(key, sizeof(key), "%016d", k);
-
-        // Bind key value into read_stmt
-        status = sqlite3_bind_blob(read_stmt, 1, key, 16, SQLITE_STATIC);
-        ErrorCheck(status);
-
-        // Execute read statement
-        while ((status = sqlite3_step(read_stmt)) == SQLITE_ROW) {
-        }
-        StepErrorCheck(status);
-
-        // Reset SQLite statement for another use
-        status = sqlite3_clear_bindings(read_stmt);
-        ErrorCheck(status);
-        status = sqlite3_reset(read_stmt);
-        ErrorCheck(status);
-        FinishedSingleOp();
-      }
-
-      // End read transaction
-      if (FLAGS_transaction && transaction) {
-        status = sqlite3_step(end_trans_stmt);
-        StepErrorCheck(status);
-        status = sqlite3_reset(end_trans_stmt);
-        ErrorCheck(status);
-      }
-    }
-
-    status = sqlite3_finalize(read_stmt);
-    ErrorCheck(status);
-    status = sqlite3_finalize(begin_trans_stmt);
-    ErrorCheck(status);
-    status = sqlite3_finalize(end_trans_stmt);
-    ErrorCheck(status);
-  }
-
-  void ReadSequential() {
-    int status;
-    sqlite3_stmt* pStmt;
-    std::string read_str = "SELECT * FROM test ORDER BY key";
-
-    status = sqlite3_prepare_v2(db_, read_str.c_str(), -1, &pStmt, nullptr);
-    ErrorCheck(status);
-    for (int i = 0; i < reads_ && SQLITE_ROW == sqlite3_step(pStmt); i++) {
-      bytes_ += sqlite3_column_bytes(pStmt, 1) + sqlite3_column_bytes(pStmt, 2);
-      FinishedSingleOp();
-    }
-
-    status = sqlite3_finalize(pStmt);
-    ErrorCheck(status);
-  }
-};
-
-}  // namespace leveldb
-
-int main(int argc, char** argv) {
-  std::string default_db_path;
-  for (int i = 1; i < argc; i++) {
-    double d;
-    int n;
-    char junk;
-    if (leveldb::Slice(argv[i]).starts_with("--benchmarks=")) {
-      FLAGS_benchmarks = argv[i] + strlen("--benchmarks=");
-    } else if (sscanf(argv[i], "--histogram=%d%c", &n, &junk) == 1 &&
-               (n == 0 || n == 1)) {
-      FLAGS_histogram = n;
-    } else if (sscanf(argv[i], "--compression_ratio=%lf%c", &d, &junk) == 1) {
-      FLAGS_compression_ratio = d;
-    } else if (sscanf(argv[i], "--use_existing_db=%d%c", &n, &junk) == 1 &&
-               (n == 0 || n == 1)) {
-      FLAGS_use_existing_db = n;
-    } else if (sscanf(argv[i], "--num=%d%c", &n, &junk) == 1) {
-      FLAGS_num = n;
-    } else if (sscanf(argv[i], "--reads=%d%c", &n, &junk) == 1) {
-      FLAGS_reads = n;
-    } else if (sscanf(argv[i], "--value_size=%d%c", &n, &junk) == 1) {
-      FLAGS_value_size = n;
-    } else if (leveldb::Slice(argv[i]) == leveldb::Slice("--no_transaction")) {
-      FLAGS_transaction = false;
-    } else if (sscanf(argv[i], "--page_size=%d%c", &n, &junk) == 1) {
-      FLAGS_page_size = n;
-    } else if (sscanf(argv[i], "--num_pages=%d%c", &n, &junk) == 1) {
-      FLAGS_num_pages = n;
-    } else if (sscanf(argv[i], "--WAL_enabled=%d%c", &n, &junk) == 1 &&
-               (n == 0 || n == 1)) {
-      FLAGS_WAL_enabled = n;
-    } else if (strncmp(argv[i], "--db=", 5) == 0) {
-      FLAGS_db = argv[i] + 5;
-    } else {
-      fprintf(stderr, "Invalid flag '%s'\n", argv[i]);
-      exit(1);
-    }
-  }
-
-  // Choose a location for the test database if none given with --db=<path>
-  if (FLAGS_db == nullptr) {
-    leveldb::Env::Default()->GetTestDirectory(&default_db_path);
-    default_db_path += "/dbbench";
-    FLAGS_db = default_db_path.c_str();
-  }
-
-  leveldb::Benchmark benchmark;
-  benchmark.Run();
-  return 0;
-}
diff --git a/doc/bench/db_bench_tree_db.cc b/doc/bench/db_bench_tree_db.cc
deleted file mode 100644
index b2f6646..0000000
--- a/doc/bench/db_bench_tree_db.cc
+++ /dev/null
@@ -1,522 +0,0 @@
-// 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 <kcpolydb.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "util/histogram.h"
-#include "util/random.h"
-#include "util/testutil.h"
-
-// Comma-separated list of operations to run in the specified order
-//   Actual benchmarks:
-//
-//   fillseq       -- write N values in sequential key order in async mode
-//   fillrandom    -- write N values in random key order in async mode
-//   overwrite     -- overwrite N values in random key order in async mode
-//   fillseqsync   -- write N/100 values in sequential key order in sync mode
-//   fillrandsync  -- write N/100 values in random key order in sync mode
-//   fillrand100K  -- write N/1000 100K values in random order in async mode
-//   fillseq100K   -- write N/1000 100K values in seq order in async mode
-//   readseq       -- read N times sequentially
-//   readseq100K   -- read N/1000 100K values in sequential order in async mode
-//   readrand100K  -- read N/1000 100K values in sequential order in async mode
-//   readrandom    -- read N times in random order
-static const char* FLAGS_benchmarks =
-    "fillseq,"
-    "fillseqsync,"
-    "fillrandsync,"
-    "fillrandom,"
-    "overwrite,"
-    "readrandom,"
-    "readseq,"
-    "fillrand100K,"
-    "fillseq100K,"
-    "readseq100K,"
-    "readrand100K,";
-
-// Number of key/values to place in database
-static int FLAGS_num = 1000000;
-
-// Number of read operations to do.  If negative, do FLAGS_num reads.
-static int FLAGS_reads = -1;
-
-// Size of each value
-static int FLAGS_value_size = 100;
-
-// Arrange to generate values that shrink to this fraction of
-// their original size after compression
-static double FLAGS_compression_ratio = 0.5;
-
-// Print histogram of operation timings
-static bool FLAGS_histogram = false;
-
-// Cache size. Default 4 MB
-static int FLAGS_cache_size = 4194304;
-
-// Page size. Default 1 KB
-static int FLAGS_page_size = 1024;
-
-// If true, do not destroy the existing database.  If you set this
-// flag and also specify a benchmark that wants a fresh database, that
-// benchmark will fail.
-static bool FLAGS_use_existing_db = false;
-
-// Compression flag. If true, compression is on. If false, compression
-// is off.
-static bool FLAGS_compression = true;
-
-// Use the db with the following name.
-static const char* FLAGS_db = nullptr;
-
-inline static void DBSynchronize(kyotocabinet::TreeDB* db_) {
-  // Synchronize will flush writes to disk
-  if (!db_->synchronize()) {
-    fprintf(stderr, "synchronize error: %s\n", db_->error().name());
-  }
-}
-
-namespace leveldb {
-
-// Helper for quickly generating random data.
-namespace {
-class RandomGenerator {
- private:
-  std::string data_;
-  int pos_;
-
- public:
-  RandomGenerator() {
-    // We use a limited amount of data over and over again and ensure
-    // that it is larger than the compression window (32KB), and also
-    // large enough to serve all typical value sizes we want to write.
-    Random rnd(301);
-    std::string piece;
-    while (data_.size() < 1048576) {
-      // Add a short fragment that is as compressible as specified
-      // by FLAGS_compression_ratio.
-      test::CompressibleString(&rnd, FLAGS_compression_ratio, 100, &piece);
-      data_.append(piece);
-    }
-    pos_ = 0;
-  }
-
-  Slice Generate(int len) {
-    if (pos_ + len > data_.size()) {
-      pos_ = 0;
-      assert(len < data_.size());
-    }
-    pos_ += len;
-    return Slice(data_.data() + pos_ - len, len);
-  }
-};
-
-static Slice TrimSpace(Slice s) {
-  int start = 0;
-  while (start < s.size() && isspace(s[start])) {
-    start++;
-  }
-  int limit = s.size();
-  while (limit > start && isspace(s[limit - 1])) {
-    limit--;
-  }
-  return Slice(s.data() + start, limit - start);
-}
-
-}  // namespace
-
-class Benchmark {
- private:
-  kyotocabinet::TreeDB* db_;
-  int db_num_;
-  int num_;
-  int reads_;
-  double start_;
-  double last_op_finish_;
-  int64_t bytes_;
-  std::string message_;
-  Histogram hist_;
-  RandomGenerator gen_;
-  Random rand_;
-  kyotocabinet::LZOCompressor<kyotocabinet::LZO::RAW> comp_;
-
-  // State kept for progress messages
-  int done_;
-  int next_report_;  // When to report next
-
-  void PrintHeader() {
-    const int kKeySize = 16;
-    PrintEnvironment();
-    fprintf(stdout, "Keys:       %d bytes each\n", kKeySize);
-    fprintf(stdout, "Values:     %d bytes each (%d bytes after compression)\n",
-            FLAGS_value_size,
-            static_cast<int>(FLAGS_value_size * FLAGS_compression_ratio + 0.5));
-    fprintf(stdout, "Entries:    %d\n", num_);
-    fprintf(stdout, "RawSize:    %.1f MB (estimated)\n",
-            ((static_cast<int64_t>(kKeySize + FLAGS_value_size) * num_) /
-             1048576.0));
-    fprintf(stdout, "FileSize:   %.1f MB (estimated)\n",
-            (((kKeySize + FLAGS_value_size * FLAGS_compression_ratio) * num_) /
-             1048576.0));
-    PrintWarnings();
-    fprintf(stdout, "------------------------------------------------\n");
-  }
-
-  void PrintWarnings() {
-#if defined(__GNUC__) && !defined(__OPTIMIZE__)
-    fprintf(
-        stdout,
-        "WARNING: Optimization is disabled: benchmarks unnecessarily slow\n");
-#endif
-#ifndef NDEBUG
-    fprintf(stdout,
-            "WARNING: Assertions are enabled; benchmarks unnecessarily slow\n");
-#endif
-  }
-
-  void PrintEnvironment() {
-    fprintf(stderr, "Kyoto Cabinet:    version %s, lib ver %d, lib rev %d\n",
-            kyotocabinet::VERSION, kyotocabinet::LIBVER, kyotocabinet::LIBREV);
-
-#if defined(__linux)
-    time_t now = time(nullptr);
-    fprintf(stderr, "Date:           %s", ctime(&now));  // ctime() adds newline
-
-    FILE* cpuinfo = fopen("/proc/cpuinfo", "r");
-    if (cpuinfo != nullptr) {
-      char line[1000];
-      int num_cpus = 0;
-      std::string cpu_type;
-      std::string cache_size;
-      while (fgets(line, sizeof(line), cpuinfo) != nullptr) {
-        const char* sep = strchr(line, ':');
-        if (sep == nullptr) {
-          continue;
-        }
-        Slice key = TrimSpace(Slice(line, sep - 1 - line));
-        Slice val = TrimSpace(Slice(sep + 1));
-        if (key == "model name") {
-          ++num_cpus;
-          cpu_type = val.ToString();
-        } else if (key == "cache size") {
-          cache_size = val.ToString();
-        }
-      }
-      fclose(cpuinfo);
-      fprintf(stderr, "CPU:            %d * %s\n", num_cpus, cpu_type.c_str());
-      fprintf(stderr, "CPUCache:       %s\n", cache_size.c_str());
-    }
-#endif
-  }
-
-  void Start() {
-    start_ = Env::Default()->NowMicros() * 1e-6;
-    bytes_ = 0;
-    message_.clear();
-    last_op_finish_ = start_;
-    hist_.Clear();
-    done_ = 0;
-    next_report_ = 100;
-  }
-
-  void FinishedSingleOp() {
-    if (FLAGS_histogram) {
-      double now = Env::Default()->NowMicros() * 1e-6;
-      double micros = (now - last_op_finish_) * 1e6;
-      hist_.Add(micros);
-      if (micros > 20000) {
-        fprintf(stderr, "long op: %.1f micros%30s\r", micros, "");
-        fflush(stderr);
-      }
-      last_op_finish_ = now;
-    }
-
-    done_++;
-    if (done_ >= next_report_) {
-      if (next_report_ < 1000)
-        next_report_ += 100;
-      else if (next_report_ < 5000)
-        next_report_ += 500;
-      else if (next_report_ < 10000)
-        next_report_ += 1000;
-      else if (next_report_ < 50000)
-        next_report_ += 5000;
-      else if (next_report_ < 100000)
-        next_report_ += 10000;
-      else if (next_report_ < 500000)
-        next_report_ += 50000;
-      else
-        next_report_ += 100000;
-      fprintf(stderr, "... finished %d ops%30s\r", done_, "");
-      fflush(stderr);
-    }
-  }
-
-  void Stop(const Slice& name) {
-    double finish = Env::Default()->NowMicros() * 1e-6;
-
-    // Pretend at least one op was done in case we are running a benchmark
-    // that does not call FinishedSingleOp().
-    if (done_ < 1) done_ = 1;
-
-    if (bytes_ > 0) {
-      char rate[100];
-      snprintf(rate, sizeof(rate), "%6.1f MB/s",
-               (bytes_ / 1048576.0) / (finish - start_));
-      if (!message_.empty()) {
-        message_ = std::string(rate) + " " + message_;
-      } else {
-        message_ = rate;
-      }
-    }
-
-    fprintf(stdout, "%-12s : %11.3f micros/op;%s%s\n", name.ToString().c_str(),
-            (finish - start_) * 1e6 / done_, (message_.empty() ? "" : " "),
-            message_.c_str());
-    if (FLAGS_histogram) {
-      fprintf(stdout, "Microseconds per op:\n%s\n", hist_.ToString().c_str());
-    }
-    fflush(stdout);
-  }
-
- public:
-  enum Order { SEQUENTIAL, RANDOM };
-  enum DBState { FRESH, EXISTING };
-
-  Benchmark()
-      : db_(nullptr),
-        num_(FLAGS_num),
-        reads_(FLAGS_reads < 0 ? FLAGS_num : FLAGS_reads),
-        bytes_(0),
-        rand_(301) {
-    std::vector<std::string> files;
-    std::string test_dir;
-    Env::Default()->GetTestDirectory(&test_dir);
-    Env::Default()->GetChildren(test_dir.c_str(), &files);
-    if (!FLAGS_use_existing_db) {
-      for (int i = 0; i < files.size(); i++) {
-        if (Slice(files[i]).starts_with("dbbench_polyDB")) {
-          std::string file_name(test_dir);
-          file_name += "/";
-          file_name += files[i];
-          Env::Default()->DeleteFile(file_name.c_str());
-        }
-      }
-    }
-  }
-
-  ~Benchmark() {
-    if (!db_->close()) {
-      fprintf(stderr, "close error: %s\n", db_->error().name());
-    }
-  }
-
-  void Run() {
-    PrintHeader();
-    Open(false);
-
-    const char* benchmarks = FLAGS_benchmarks;
-    while (benchmarks != nullptr) {
-      const char* sep = strchr(benchmarks, ',');
-      Slice name;
-      if (sep == nullptr) {
-        name = benchmarks;
-        benchmarks = nullptr;
-      } else {
-        name = Slice(benchmarks, sep - benchmarks);
-        benchmarks = sep + 1;
-      }
-
-      Start();
-
-      bool known = true;
-      bool write_sync = false;
-      if (name == Slice("fillseq")) {
-        Write(write_sync, SEQUENTIAL, FRESH, num_, FLAGS_value_size, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("fillrandom")) {
-        Write(write_sync, RANDOM, FRESH, num_, FLAGS_value_size, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("overwrite")) {
-        Write(write_sync, RANDOM, EXISTING, num_, FLAGS_value_size, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("fillrandsync")) {
-        write_sync = true;
-        Write(write_sync, RANDOM, FRESH, num_ / 100, FLAGS_value_size, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("fillseqsync")) {
-        write_sync = true;
-        Write(write_sync, SEQUENTIAL, FRESH, num_ / 100, FLAGS_value_size, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("fillrand100K")) {
-        Write(write_sync, RANDOM, FRESH, num_ / 1000, 100 * 1000, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("fillseq100K")) {
-        Write(write_sync, SEQUENTIAL, FRESH, num_ / 1000, 100 * 1000, 1);
-        DBSynchronize(db_);
-      } else if (name == Slice("readseq")) {
-        ReadSequential();
-      } else if (name == Slice("readrandom")) {
-        ReadRandom();
-      } else if (name == Slice("readrand100K")) {
-        int n = reads_;
-        reads_ /= 1000;
-        ReadRandom();
-        reads_ = n;
-      } else if (name == Slice("readseq100K")) {
-        int n = reads_;
-        reads_ /= 1000;
-        ReadSequential();
-        reads_ = n;
-      } else {
-        known = false;
-        if (name != Slice()) {  // No error message for empty name
-          fprintf(stderr, "unknown benchmark '%s'\n", name.ToString().c_str());
-        }
-      }
-      if (known) {
-        Stop(name);
-      }
-    }
-  }
-
- private:
-  void Open(bool sync) {
-    assert(db_ == nullptr);
-
-    // Initialize db_
-    db_ = new kyotocabinet::TreeDB();
-    char file_name[100];
-    db_num_++;
-    std::string test_dir;
-    Env::Default()->GetTestDirectory(&test_dir);
-    snprintf(file_name, sizeof(file_name), "%s/dbbench_polyDB-%d.kct",
-             test_dir.c_str(), db_num_);
-
-    // Create tuning options and open the database
-    int open_options =
-        kyotocabinet::PolyDB::OWRITER | kyotocabinet::PolyDB::OCREATE;
-    int tune_options =
-        kyotocabinet::TreeDB::TSMALL | kyotocabinet::TreeDB::TLINEAR;
-    if (FLAGS_compression) {
-      tune_options |= kyotocabinet::TreeDB::TCOMPRESS;
-      db_->tune_compressor(&comp_);
-    }
-    db_->tune_options(tune_options);
-    db_->tune_page_cache(FLAGS_cache_size);
-    db_->tune_page(FLAGS_page_size);
-    db_->tune_map(256LL << 20);
-    if (sync) {
-      open_options |= kyotocabinet::PolyDB::OAUTOSYNC;
-    }
-    if (!db_->open(file_name, open_options)) {
-      fprintf(stderr, "open error: %s\n", db_->error().name());
-    }
-  }
-
-  void Write(bool sync, Order order, DBState state, int num_entries,
-             int value_size, int entries_per_batch) {
-    // Create new database if state == FRESH
-    if (state == FRESH) {
-      if (FLAGS_use_existing_db) {
-        message_ = "skipping (--use_existing_db is true)";
-        return;
-      }
-      delete db_;
-      db_ = nullptr;
-      Open(sync);
-      Start();  // Do not count time taken to destroy/open
-    }
-
-    if (num_entries != num_) {
-      char msg[100];
-      snprintf(msg, sizeof(msg), "(%d ops)", num_entries);
-      message_ = msg;
-    }
-
-    // Write to database
-    for (int i = 0; i < num_entries; i++) {
-      const int k = (order == SEQUENTIAL) ? i : (rand_.Next() % num_entries);
-      char key[100];
-      snprintf(key, sizeof(key), "%016d", k);
-      bytes_ += value_size + strlen(key);
-      std::string cpp_key = key;
-      if (!db_->set(cpp_key, gen_.Generate(value_size).ToString())) {
-        fprintf(stderr, "set error: %s\n", db_->error().name());
-      }
-      FinishedSingleOp();
-    }
-  }
-
-  void ReadSequential() {
-    kyotocabinet::DB::Cursor* cur = db_->cursor();
-    cur->jump();
-    std::string ckey, cvalue;
-    while (cur->get(&ckey, &cvalue, true)) {
-      bytes_ += ckey.size() + cvalue.size();
-      FinishedSingleOp();
-    }
-    delete cur;
-  }
-
-  void ReadRandom() {
-    std::string value;
-    for (int i = 0; i < reads_; i++) {
-      char key[100];
-      const int k = rand_.Next() % reads_;
-      snprintf(key, sizeof(key), "%016d", k);
-      db_->get(key, &value);
-      FinishedSingleOp();
-    }
-  }
-};
-
-}  // namespace leveldb
-
-int main(int argc, char** argv) {
-  std::string default_db_path;
-  for (int i = 1; i < argc; i++) {
-    double d;
-    int n;
-    char junk;
-    if (leveldb::Slice(argv[i]).starts_with("--benchmarks=")) {
-      FLAGS_benchmarks = argv[i] + strlen("--benchmarks=");
-    } else if (sscanf(argv[i], "--compression_ratio=%lf%c", &d, &junk) == 1) {
-      FLAGS_compression_ratio = d;
-    } else if (sscanf(argv[i], "--histogram=%d%c", &n, &junk) == 1 &&
-               (n == 0 || n == 1)) {
-      FLAGS_histogram = n;
-    } else if (sscanf(argv[i], "--num=%d%c", &n, &junk) == 1) {
-      FLAGS_num = n;
-    } else if (sscanf(argv[i], "--reads=%d%c", &n, &junk) == 1) {
-      FLAGS_reads = n;
-    } else if (sscanf(argv[i], "--value_size=%d%c", &n, &junk) == 1) {
-      FLAGS_value_size = n;
-    } else if (sscanf(argv[i], "--cache_size=%d%c", &n, &junk) == 1) {
-      FLAGS_cache_size = n;
-    } else if (sscanf(argv[i], "--page_size=%d%c", &n, &junk) == 1) {
-      FLAGS_page_size = n;
-    } else if (sscanf(argv[i], "--compression=%d%c", &n, &junk) == 1 &&
-               (n == 0 || n == 1)) {
-      FLAGS_compression = (n == 1) ? true : false;
-    } else if (strncmp(argv[i], "--db=", 5) == 0) {
-      FLAGS_db = argv[i] + 5;
-    } else {
-      fprintf(stderr, "Invalid flag '%s'\n", argv[i]);
-      exit(1);
-    }
-  }
-
-  // Choose a location for the test database if none given with --db=<path>
-  if (FLAGS_db == nullptr) {
-    leveldb::Env::Default()->GetTestDirectory(&default_db_path);
-    default_db_path += "/dbbench";
-    FLAGS_db = default_db_path.c_str();
-  }
-
-  leveldb::Benchmark benchmark;
-  benchmark.Run();
-  return 0;
-}
diff --git a/doc/benchmark.html b/doc/benchmark.html
index c463977..f3fd771 100644
--- a/doc/benchmark.html
+++ b/doc/benchmark.html
@@ -90,9 +90,9 @@ div.bsql {
 <h4>Benchmark Source Code</h4>
 <p>We wrote benchmark tools for SQLite and Kyoto TreeDB based on LevelDB's <span class="code">db_bench</span>. The code for each of the benchmarks resides here:</p>
 <ul>
-	<li> <b>LevelDB:</b> <a href="http://code.google.com/p/leveldb/source/browse/trunk/db/db_bench.cc">db/db_bench.cc</a>.</li>
-	<li> <b>SQLite:</b> <a href="http://code.google.com/p/leveldb/source/browse/#svn%2Ftrunk%2Fdoc%2Fbench%2Fdb_bench_sqlite3.cc">doc/bench/db_bench_sqlite3.cc</a>.</li>
-	<li> <b>Kyoto TreeDB:</b> <a href="http://code.google.com/p/leveldb/source/browse/#svn%2Ftrunk%2Fdoc%2Fbench%2Fdb_bench_tree_db.cc">doc/bench/db_bench_tree_db.cc</a>.</li>
+	<li> <b>LevelDB:</b> <a href="https://github.com/google/leveldb/blob/master/benchmarks/db_bench.cc">benchmarks/db_bench.cc</a>.</li>
+	<li> <b>SQLite:</b> <a href="https://github.com/google/leveldb/blob/master/benchmarks/db_bench_sqlite3.cc">benchmarks/db_bench_sqlite3.cc</a>.</li>
+	<li> <b>Kyoto TreeDB:</b> <a href="https://github.com/google/leveldb/blob/master/benchmarks/db_bench_tree_db.cc">benchmarks/db_bench_tree_db.cc</a>.</li>
 </ul>
 
 <h4>Custom Build Specifications</h4>