1// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file. See the AUTHORS file for names of contributors.
4
5#include <stdio.h>
6#include <stdlib.h>
7#include <sqlite3.h>
8#include "util/histogram.h"
9#include "util/random.h"
10#include "util/testutil.h"
11
12// Comma-separated list of operations to run in the specified order
13//   Actual benchmarks:
14//
15//   fillseq       -- write N values in sequential key order in async mode
16//   fillseqsync   -- write N/100 values in sequential key order in sync mode
17//   fillseqbatch  -- batch write N values in sequential key order in async mode
18//   fillrandom    -- write N values in random key order in async mode
19//   fillrandsync  -- write N/100 values in random key order in sync mode
20//   fillrandbatch -- batch write N values in sequential key order in async mode
21//   overwrite     -- overwrite N values in random key order in async mode
22//   fillrand100K  -- write N/1000 100K values in random order in async mode
23//   fillseq100K   -- write N/1000 100K values in sequential order in async mode
24//   readseq       -- read N times sequentially
25//   readrandom    -- read N times in random order
26//   readrand100K  -- read N/1000 100K values in sequential order in async mode
27static const char* FLAGS_benchmarks =
28    "fillseq,"
29    "fillseqsync,"
30    "fillseqbatch,"
31    "fillrandom,"
32    "fillrandsync,"
33    "fillrandbatch,"
34    "overwrite,"
35    "overwritebatch,"
36    "readrandom,"
37    "readseq,"
38    "fillrand100K,"
39    "fillseq100K,"
40    "readseq,"
41    "readrand100K,"
42    ;
43
44// Number of key/values to place in database
45static int FLAGS_num = 1000000;
46
47// Number of read operations to do.  If negative, do FLAGS_num reads.
48static int FLAGS_reads = -1;
49
50// Size of each value
51static int FLAGS_value_size = 100;
52
53// Print histogram of operation timings
54static bool FLAGS_histogram = false;
55
56// Arrange to generate values that shrink to this fraction of
57// their original size after compression
58static double FLAGS_compression_ratio = 0.5;
59
60// Page size. Default 1 KB.
61static int FLAGS_page_size = 1024;
62
63// Number of pages.
64// Default cache size = FLAGS_page_size * FLAGS_num_pages = 4 MB.
65static int FLAGS_num_pages = 4096;
66
67// If true, do not destroy the existing database.  If you set this
68// flag and also specify a benchmark that wants a fresh database, that
69// benchmark will fail.
70static bool FLAGS_use_existing_db = false;
71
72// If true, we allow batch writes to occur
73static bool FLAGS_transaction = true;
74
75// If true, we enable Write-Ahead Logging
76static bool FLAGS_WAL_enabled = true;
77
78// Use the db with the following name.
79static const char* FLAGS_db = NULL;
80
81inline
82static void ExecErrorCheck(int status, char *err_msg) {
83  if (status != SQLITE_OK) {
84    fprintf(stderr, "SQL error: %s\n", err_msg);
85    sqlite3_free(err_msg);
86    exit(1);
87  }
88}
89
90inline
91static void StepErrorCheck(int status) {
92  if (status != SQLITE_DONE) {
93    fprintf(stderr, "SQL step error: status = %d\n", status);
94    exit(1);
95  }
96}
97
98inline
99static void ErrorCheck(int status) {
100  if (status != SQLITE_OK) {
101    fprintf(stderr, "sqlite3 error: status = %d\n", status);
102    exit(1);
103  }
104}
105
106inline
107static void WalCheckpoint(sqlite3* db_) {
108  // Flush all writes to disk
109  if (FLAGS_WAL_enabled) {
110    sqlite3_wal_checkpoint_v2(db_, NULL, SQLITE_CHECKPOINT_FULL, NULL, NULL);
111  }
112}
113
114namespace leveldb {
115
116// Helper for quickly generating random data.
117namespace {
118class RandomGenerator {
119 private:
120  std::string data_;
121  int pos_;
122
123 public:
124  RandomGenerator() {
125    // We use a limited amount of data over and over again and ensure
126    // that it is larger than the compression window (32KB), and also
127    // large enough to serve all typical value sizes we want to write.
128    Random rnd(301);
129    std::string piece;
130    while (data_.size() < 1048576) {
131      // Add a short fragment that is as compressible as specified
132      // by FLAGS_compression_ratio.
133      test::CompressibleString(&rnd, FLAGS_compression_ratio, 100, &piece);
134      data_.append(piece);
135    }
136    pos_ = 0;
137  }
138
139  Slice Generate(int len) {
140    if (pos_ + len > data_.size()) {
141      pos_ = 0;
142      assert(len < data_.size());
143    }
144    pos_ += len;
145    return Slice(data_.data() + pos_ - len, len);
146  }
147};
148
149static Slice TrimSpace(Slice s) {
150  int start = 0;
151  while (start < s.size() && isspace(s[start])) {
152    start++;
153  }
154  int limit = s.size();
155  while (limit > start && isspace(s[limit-1])) {
156    limit--;
157  }
158  return Slice(s.data() + start, limit - start);
159}
160
161}  // namespace
162
163class Benchmark {
164 private:
165  sqlite3* db_;
166  int db_num_;
167  int num_;
168  int reads_;
169  double start_;
170  double last_op_finish_;
171  int64_t bytes_;
172  std::string message_;
173  Histogram hist_;
174  RandomGenerator gen_;
175  Random rand_;
176
177  // State kept for progress messages
178  int done_;
179  int next_report_;     // When to report next
180
181  void PrintHeader() {
182    const int kKeySize = 16;
183    PrintEnvironment();
184    fprintf(stdout, "Keys:       %d bytes each\n", kKeySize);
185    fprintf(stdout, "Values:     %d bytes each\n", FLAGS_value_size);
186    fprintf(stdout, "Entries:    %d\n", num_);
187    fprintf(stdout, "RawSize:    %.1f MB (estimated)\n",
188            ((static_cast<int64_t>(kKeySize + FLAGS_value_size) * num_)
189             / 1048576.0));
190    PrintWarnings();
191    fprintf(stdout, "------------------------------------------------\n");
192  }
193
194  void PrintWarnings() {
195#if defined(__GNUC__) && !defined(__OPTIMIZE__)
196    fprintf(stdout,
197            "WARNING: Optimization is disabled: benchmarks unnecessarily slow\n"
198            );
199#endif
200#ifndef NDEBUG
201    fprintf(stdout,
202            "WARNING: Assertions are enabled; benchmarks unnecessarily slow\n");
203#endif
204  }
205
206  void PrintEnvironment() {
207    fprintf(stderr, "SQLite:     version %s\n", SQLITE_VERSION);
208
209#if defined(__linux)
210    time_t now = time(NULL);
211    fprintf(stderr, "Date:       %s", ctime(&now));  // ctime() adds newline
212
213    FILE* cpuinfo = fopen("/proc/cpuinfo", "r");
214    if (cpuinfo != NULL) {
215      char line[1000];
216      int num_cpus = 0;
217      std::string cpu_type;
218      std::string cache_size;
219      while (fgets(line, sizeof(line), cpuinfo) != NULL) {
220        const char* sep = strchr(line, ':');
221        if (sep == NULL) {
222          continue;
223        }
224        Slice key = TrimSpace(Slice(line, sep - 1 - line));
225        Slice val = TrimSpace(Slice(sep + 1));
226        if (key == "model name") {
227          ++num_cpus;
228          cpu_type = val.ToString();
229        } else if (key == "cache size") {
230          cache_size = val.ToString();
231        }
232      }
233      fclose(cpuinfo);
234      fprintf(stderr, "CPU:        %d * %s\n", num_cpus, cpu_type.c_str());
235      fprintf(stderr, "CPUCache:   %s\n", cache_size.c_str());
236    }
237#endif
238  }
239
240  void Start() {
241    start_ = Env::Default()->NowMicros() * 1e-6;
242    bytes_ = 0;
243    message_.clear();
244    last_op_finish_ = start_;
245    hist_.Clear();
246    done_ = 0;
247    next_report_ = 100;
248  }
249
250  void FinishedSingleOp() {
251    if (FLAGS_histogram) {
252      double now = Env::Default()->NowMicros() * 1e-6;
253      double micros = (now - last_op_finish_) * 1e6;
254      hist_.Add(micros);
255      if (micros > 20000) {
256        fprintf(stderr, "long op: %.1f micros%30s\r", micros, "");
257        fflush(stderr);
258      }
259      last_op_finish_ = now;
260    }
261
262    done_++;
263    if (done_ >= next_report_) {
264      if      (next_report_ < 1000)   next_report_ += 100;
265      else if (next_report_ < 5000)   next_report_ += 500;
266      else if (next_report_ < 10000)  next_report_ += 1000;
267      else if (next_report_ < 50000)  next_report_ += 5000;
268      else if (next_report_ < 100000) next_report_ += 10000;
269      else if (next_report_ < 500000) next_report_ += 50000;
270      else                            next_report_ += 100000;
271      fprintf(stderr, "... finished %d ops%30s\r", done_, "");
272      fflush(stderr);
273    }
274  }
275
276  void Stop(const Slice& name) {
277    double finish = Env::Default()->NowMicros() * 1e-6;
278
279    // Pretend at least one op was done in case we are running a benchmark
280    // that does not call FinishedSingleOp().
281    if (done_ < 1) done_ = 1;
282
283    if (bytes_ > 0) {
284      char rate[100];
285      snprintf(rate, sizeof(rate), "%6.1f MB/s",
286               (bytes_ / 1048576.0) / (finish - start_));
287      if (!message_.empty()) {
288        message_  = std::string(rate) + " " + message_;
289      } else {
290        message_ = rate;
291      }
292    }
293
294    fprintf(stdout, "%-12s : %11.3f micros/op;%s%s\n",
295            name.ToString().c_str(),
296            (finish - start_) * 1e6 / done_,
297            (message_.empty() ? "" : " "),
298            message_.c_str());
299    if (FLAGS_histogram) {
300      fprintf(stdout, "Microseconds per op:\n%s\n", hist_.ToString().c_str());
301    }
302    fflush(stdout);
303  }
304
305 public:
306  enum Order {
307    SEQUENTIAL,
308    RANDOM
309  };
310  enum DBState {
311    FRESH,
312    EXISTING
313  };
314
315  Benchmark()
316  : db_(NULL),
317    db_num_(0),
318    num_(FLAGS_num),
319    reads_(FLAGS_reads < 0 ? FLAGS_num : FLAGS_reads),
320    bytes_(0),
321    rand_(301) {
322    std::vector<std::string> files;
323    std::string test_dir;
324    Env::Default()->GetTestDirectory(&test_dir);
325    Env::Default()->GetChildren(test_dir, &files);
326    if (!FLAGS_use_existing_db) {
327      for (int i = 0; i < files.size(); i++) {
328        if (Slice(files[i]).starts_with("dbbench_sqlite3")) {
329          std::string file_name(test_dir);
330          file_name += "/";
331          file_name += files[i];
332          Env::Default()->DeleteFile(file_name.c_str());
333        }
334      }
335    }
336  }
337
338  ~Benchmark() {
339    int status = sqlite3_close(db_);
340    ErrorCheck(status);
341  }
342
343  void Run() {
344    PrintHeader();
345    Open();
346
347    const char* benchmarks = FLAGS_benchmarks;
348    while (benchmarks != NULL) {
349      const char* sep = strchr(benchmarks, ',');
350      Slice name;
351      if (sep == NULL) {
352        name = benchmarks;
353        benchmarks = NULL;
354      } else {
355        name = Slice(benchmarks, sep - benchmarks);
356        benchmarks = sep + 1;
357      }
358
359      bytes_ = 0;
360      Start();
361
362      bool known = true;
363      bool write_sync = false;
364      if (name == Slice("fillseq")) {
365        Write(write_sync, SEQUENTIAL, FRESH, num_, FLAGS_value_size, 1);
366        WalCheckpoint(db_);
367      } else if (name == Slice("fillseqbatch")) {
368        Write(write_sync, SEQUENTIAL, FRESH, num_, FLAGS_value_size, 1000);
369        WalCheckpoint(db_);
370      } else if (name == Slice("fillrandom")) {
371        Write(write_sync, RANDOM, FRESH, num_, FLAGS_value_size, 1);
372        WalCheckpoint(db_);
373      } else if (name == Slice("fillrandbatch")) {
374        Write(write_sync, RANDOM, FRESH, num_, FLAGS_value_size, 1000);
375        WalCheckpoint(db_);
376      } else if (name == Slice("overwrite")) {
377        Write(write_sync, RANDOM, EXISTING, num_, FLAGS_value_size, 1);
378        WalCheckpoint(db_);
379      } else if (name == Slice("overwritebatch")) {
380        Write(write_sync, RANDOM, EXISTING, num_, FLAGS_value_size, 1000);
381        WalCheckpoint(db_);
382      } else if (name == Slice("fillrandsync")) {
383        write_sync = true;
384        Write(write_sync, RANDOM, FRESH, num_ / 100, FLAGS_value_size, 1);
385        WalCheckpoint(db_);
386      } else if (name == Slice("fillseqsync")) {
387        write_sync = true;
388        Write(write_sync, SEQUENTIAL, FRESH, num_ / 100, FLAGS_value_size, 1);
389        WalCheckpoint(db_);
390      } else if (name == Slice("fillrand100K")) {
391        Write(write_sync, RANDOM, FRESH, num_ / 1000, 100 * 1000, 1);
392        WalCheckpoint(db_);
393      } else if (name == Slice("fillseq100K")) {
394        Write(write_sync, SEQUENTIAL, FRESH, num_ / 1000, 100 * 1000, 1);
395        WalCheckpoint(db_);
396      } else if (name == Slice("readseq")) {
397        ReadSequential();
398      } else if (name == Slice("readrandom")) {
399        Read(RANDOM, 1);
400      } else if (name == Slice("readrand100K")) {
401        int n = reads_;
402        reads_ /= 1000;
403        Read(RANDOM, 1);
404        reads_ = n;
405      } else {
406        known = false;
407        if (name != Slice()) {  // No error message for empty name
408          fprintf(stderr, "unknown benchmark '%s'\n", name.ToString().c_str());
409        }
410      }
411      if (known) {
412        Stop(name);
413      }
414    }
415  }
416
417  void Open() {
418    assert(db_ == NULL);
419
420    int status;
421    char file_name[100];
422    char* err_msg = NULL;
423    db_num_++;
424
425    // Open database
426    std::string tmp_dir;
427    Env::Default()->GetTestDirectory(&tmp_dir);
428    snprintf(file_name, sizeof(file_name),
429             "%s/dbbench_sqlite3-%d.db",
430             tmp_dir.c_str(),
431             db_num_);
432    status = sqlite3_open(file_name, &db_);
433    if (status) {
434      fprintf(stderr, "open error: %s\n", sqlite3_errmsg(db_));
435      exit(1);
436    }
437
438    // Change SQLite cache size
439    char cache_size[100];
440    snprintf(cache_size, sizeof(cache_size), "PRAGMA cache_size = %d",
441             FLAGS_num_pages);
442    status = sqlite3_exec(db_, cache_size, NULL, NULL, &err_msg);
443    ExecErrorCheck(status, err_msg);
444
445    // FLAGS_page_size is defaulted to 1024
446    if (FLAGS_page_size != 1024) {
447      char page_size[100];
448      snprintf(page_size, sizeof(page_size), "PRAGMA page_size = %d",
449               FLAGS_page_size);
450      status = sqlite3_exec(db_, page_size, NULL, NULL, &err_msg);
451      ExecErrorCheck(status, err_msg);
452    }
453
454    // Change journal mode to WAL if WAL enabled flag is on
455    if (FLAGS_WAL_enabled) {
456      std::string WAL_stmt = "PRAGMA journal_mode = WAL";
457
458      // LevelDB's default cache size is a combined 4 MB
459      std::string WAL_checkpoint = "PRAGMA wal_autocheckpoint = 4096";
460      status = sqlite3_exec(db_, WAL_stmt.c_str(), NULL, NULL, &err_msg);
461      ExecErrorCheck(status, err_msg);
462      status = sqlite3_exec(db_, WAL_checkpoint.c_str(), NULL, NULL, &err_msg);
463      ExecErrorCheck(status, err_msg);
464    }
465
466    // Change locking mode to exclusive and create tables/index for database
467    std::string locking_stmt = "PRAGMA locking_mode = EXCLUSIVE";
468    std::string create_stmt =
469          "CREATE TABLE test (key blob, value blob, PRIMARY KEY(key))";
470    std::string stmt_array[] = { locking_stmt, create_stmt };
471    int stmt_array_length = sizeof(stmt_array) / sizeof(std::string);
472    for (int i = 0; i < stmt_array_length; i++) {
473      status = sqlite3_exec(db_, stmt_array[i].c_str(), NULL, NULL, &err_msg);
474      ExecErrorCheck(status, err_msg);
475    }
476  }
477
478  void Write(bool write_sync, Order order, DBState state,
479             int num_entries, int value_size, int entries_per_batch) {
480    // Create new database if state == FRESH
481    if (state == FRESH) {
482      if (FLAGS_use_existing_db) {
483        message_ = "skipping (--use_existing_db is true)";
484        return;
485      }
486      sqlite3_close(db_);
487      db_ = NULL;
488      Open();
489      Start();
490    }
491
492    if (num_entries != num_) {
493      char msg[100];
494      snprintf(msg, sizeof(msg), "(%d ops)", num_entries);
495      message_ = msg;
496    }
497
498    char* err_msg = NULL;
499    int status;
500
501    sqlite3_stmt *replace_stmt, *begin_trans_stmt, *end_trans_stmt;
502    std::string replace_str = "REPLACE INTO test (key, value) VALUES (?, ?)";
503    std::string begin_trans_str = "BEGIN TRANSACTION;";
504    std::string end_trans_str = "END TRANSACTION;";
505
506    // Check for synchronous flag in options
507    std::string sync_stmt = (write_sync) ? "PRAGMA synchronous = FULL" :
508                                           "PRAGMA synchronous = OFF";
509    status = sqlite3_exec(db_, sync_stmt.c_str(), NULL, NULL, &err_msg);
510    ExecErrorCheck(status, err_msg);
511
512    // Preparing sqlite3 statements
513    status = sqlite3_prepare_v2(db_, replace_str.c_str(), -1,
514                                &replace_stmt, NULL);
515    ErrorCheck(status);
516    status = sqlite3_prepare_v2(db_, begin_trans_str.c_str(), -1,
517                                &begin_trans_stmt, NULL);
518    ErrorCheck(status);
519    status = sqlite3_prepare_v2(db_, end_trans_str.c_str(), -1,
520                                &end_trans_stmt, NULL);
521    ErrorCheck(status);
522
523    bool transaction = (entries_per_batch > 1);
524    for (int i = 0; i < num_entries; i += entries_per_batch) {
525      // Begin write transaction
526      if (FLAGS_transaction && transaction) {
527        status = sqlite3_step(begin_trans_stmt);
528        StepErrorCheck(status);
529        status = sqlite3_reset(begin_trans_stmt);
530        ErrorCheck(status);
531      }
532
533      // Create and execute SQL statements
534      for (int j = 0; j < entries_per_batch; j++) {
535        const char* value = gen_.Generate(value_size).data();
536
537        // Create values for key-value pair
538        const int k = (order == SEQUENTIAL) ? i + j :
539                      (rand_.Next() % num_entries);
540        char key[100];
541        snprintf(key, sizeof(key), "%016d", k);
542
543        // Bind KV values into replace_stmt
544        status = sqlite3_bind_blob(replace_stmt, 1, key, 16, SQLITE_STATIC);
545        ErrorCheck(status);
546        status = sqlite3_bind_blob(replace_stmt, 2, value,
547                                   value_size, SQLITE_STATIC);
548        ErrorCheck(status);
549
550        // Execute replace_stmt
551        bytes_ += value_size + strlen(key);
552        status = sqlite3_step(replace_stmt);
553        StepErrorCheck(status);
554
555        // Reset SQLite statement for another use
556        status = sqlite3_clear_bindings(replace_stmt);
557        ErrorCheck(status);
558        status = sqlite3_reset(replace_stmt);
559        ErrorCheck(status);
560
561        FinishedSingleOp();
562      }
563
564      // End write transaction
565      if (FLAGS_transaction && transaction) {
566        status = sqlite3_step(end_trans_stmt);
567        StepErrorCheck(status);
568        status = sqlite3_reset(end_trans_stmt);
569        ErrorCheck(status);
570      }
571    }
572
573    status = sqlite3_finalize(replace_stmt);
574    ErrorCheck(status);
575    status = sqlite3_finalize(begin_trans_stmt);
576    ErrorCheck(status);
577    status = sqlite3_finalize(end_trans_stmt);
578    ErrorCheck(status);
579  }
580
581  void Read(Order order, int entries_per_batch) {
582    int status;
583    sqlite3_stmt *read_stmt, *begin_trans_stmt, *end_trans_stmt;
584
585    std::string read_str = "SELECT * FROM test WHERE key = ?";
586    std::string begin_trans_str = "BEGIN TRANSACTION;";
587    std::string end_trans_str = "END TRANSACTION;";
588
589    // Preparing sqlite3 statements
590    status = sqlite3_prepare_v2(db_, begin_trans_str.c_str(), -1,
591                                &begin_trans_stmt, NULL);
592    ErrorCheck(status);
593    status = sqlite3_prepare_v2(db_, end_trans_str.c_str(), -1,
594                                &end_trans_stmt, NULL);
595    ErrorCheck(status);
596    status = sqlite3_prepare_v2(db_, read_str.c_str(), -1, &read_stmt, NULL);
597    ErrorCheck(status);
598
599    bool transaction = (entries_per_batch > 1);
600    for (int i = 0; i < reads_; i += entries_per_batch) {
601      // Begin read transaction
602      if (FLAGS_transaction && transaction) {
603        status = sqlite3_step(begin_trans_stmt);
604        StepErrorCheck(status);
605        status = sqlite3_reset(begin_trans_stmt);
606        ErrorCheck(status);
607      }
608
609      // Create and execute SQL statements
610      for (int j = 0; j < entries_per_batch; j++) {
611        // Create key value
612        char key[100];
613        int k = (order == SEQUENTIAL) ? i + j : (rand_.Next() % reads_);
614        snprintf(key, sizeof(key), "%016d", k);
615
616        // Bind key value into read_stmt
617        status = sqlite3_bind_blob(read_stmt, 1, key, 16, SQLITE_STATIC);
618        ErrorCheck(status);
619
620        // Execute read statement
621        while ((status = sqlite3_step(read_stmt)) == SQLITE_ROW) {}
622        StepErrorCheck(status);
623
624        // Reset SQLite statement for another use
625        status = sqlite3_clear_bindings(read_stmt);
626        ErrorCheck(status);
627        status = sqlite3_reset(read_stmt);
628        ErrorCheck(status);
629        FinishedSingleOp();
630      }
631
632      // End read transaction
633      if (FLAGS_transaction && transaction) {
634        status = sqlite3_step(end_trans_stmt);
635        StepErrorCheck(status);
636        status = sqlite3_reset(end_trans_stmt);
637        ErrorCheck(status);
638      }
639    }
640
641    status = sqlite3_finalize(read_stmt);
642    ErrorCheck(status);
643    status = sqlite3_finalize(begin_trans_stmt);
644    ErrorCheck(status);
645    status = sqlite3_finalize(end_trans_stmt);
646    ErrorCheck(status);
647  }
648
649  void ReadSequential() {
650    int status;
651    sqlite3_stmt *pStmt;
652    std::string read_str = "SELECT * FROM test ORDER BY key";
653
654    status = sqlite3_prepare_v2(db_, read_str.c_str(), -1, &pStmt, NULL);
655    ErrorCheck(status);
656    for (int i = 0; i < reads_ && SQLITE_ROW == sqlite3_step(pStmt); i++) {
657      bytes_ += sqlite3_column_bytes(pStmt, 1) + sqlite3_column_bytes(pStmt, 2);
658      FinishedSingleOp();
659    }
660
661    status = sqlite3_finalize(pStmt);
662    ErrorCheck(status);
663  }
664
665};
666
667}  // namespace leveldb
668
669int main(int argc, char** argv) {
670  std::string default_db_path;
671  for (int i = 1; i < argc; i++) {
672    double d;
673    int n;
674    char junk;
675    if (leveldb::Slice(argv[i]).starts_with("--benchmarks=")) {
676      FLAGS_benchmarks = argv[i] + strlen("--benchmarks=");
677    } else if (sscanf(argv[i], "--histogram=%d%c", &n, &junk) == 1 &&
678               (n == 0 || n == 1)) {
679      FLAGS_histogram = n;
680    } else if (sscanf(argv[i], "--compression_ratio=%lf%c", &d, &junk) == 1) {
681      FLAGS_compression_ratio = d;
682    } else if (sscanf(argv[i], "--use_existing_db=%d%c", &n, &junk) == 1 &&
683               (n == 0 || n == 1)) {
684      FLAGS_use_existing_db = n;
685    } else if (sscanf(argv[i], "--num=%d%c", &n, &junk) == 1) {
686      FLAGS_num = n;
687    } else if (sscanf(argv[i], "--reads=%d%c", &n, &junk) == 1) {
688      FLAGS_reads = n;
689    } else if (sscanf(argv[i], "--value_size=%d%c", &n, &junk) == 1) {
690      FLAGS_value_size = n;
691    } else if (leveldb::Slice(argv[i]) == leveldb::Slice("--no_transaction")) {
692      FLAGS_transaction = false;
693    } else if (sscanf(argv[i], "--page_size=%d%c", &n, &junk) == 1) {
694      FLAGS_page_size = n;
695    } else if (sscanf(argv[i], "--num_pages=%d%c", &n, &junk) == 1) {
696      FLAGS_num_pages = n;
697    } else if (sscanf(argv[i], "--WAL_enabled=%d%c", &n, &junk) == 1 &&
698               (n == 0 || n == 1)) {
699      FLAGS_WAL_enabled = n;
700    } else if (strncmp(argv[i], "--db=", 5) == 0) {
701      FLAGS_db = argv[i] + 5;
702    } else {
703      fprintf(stderr, "Invalid flag '%s'\n", argv[i]);
704      exit(1);
705    }
706  }
707
708  // Choose a location for the test database if none given with --db=<path>
709  if (FLAGS_db == NULL) {
710      leveldb::Env::Default()->GetTestDirectory(&default_db_path);
711      default_db_path += "/dbbench";
712      FLAGS_db = default_db_path.c_str();
713  }
714
715  leveldb::Benchmark benchmark;
716  benchmark.Run();
717  return 0;
718}
719