db_test_util.h 20.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
// 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
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif

#include <fcntl.h>
#include <inttypes.h>
17
#ifndef OS_WIN
18
#include <unistd.h>
19
#endif
20 21 22 23 24 25 26 27 28 29

#include <algorithm>
#include <set>
#include <string>
#include <thread>
#include <unordered_set>
#include <utility>
#include <vector>

#include "db/db_impl.h"
30
#include "db/db_test_util.h"
31 32
#include "db/dbformat.h"
#include "db/filename.h"
33
#include "memtable/hash_linklist_rep.h"
34 35
#include "rocksdb/cache.h"
#include "rocksdb/compaction_filter.h"
A
agiardullo 已提交
36
#include "rocksdb/convenience.h"
37 38 39 40 41 42 43 44 45 46
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/filter_policy.h"
#include "rocksdb/options.h"
#include "rocksdb/slice.h"
#include "rocksdb/table.h"
#include "rocksdb/utilities/checkpoint.h"
#include "table/block_based_table_factory.h"
#include "table/mock_table.h"
#include "table/plain_table_factory.h"
S
sdong 已提交
47
#include "table/scoped_arena_iterator.h"
48 49 50
#include "util/compression.h"
#include "util/mock_env.h"
#include "util/mutexlock.h"
S
sdong 已提交
51

52
#include "util/string_util.h"
53 54
// SyncPoint is not supported in Released Windows Mode.
#if !(defined NDEBUG) || !defined(OS_WIN)
55
#include "util/sync_point.h"
56
#endif  // !(defined NDEBUG) || !defined(OS_WIN)
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
#include "util/testharness.h"
#include "util/testutil.h"
#include "util/xfunc.h"
#include "utilities/merge_operators.h"

namespace rocksdb {

namespace anon {
class AtomicCounter {
 public:
  explicit AtomicCounter(Env* env = NULL)
      : env_(env), cond_count_(&mu_), count_(0) {}

  void Increment() {
    MutexLock l(&mu_);
    count_++;
    cond_count_.SignalAll();
  }

  int Read() {
    MutexLock l(&mu_);
    return count_;
  }

  bool WaitFor(int count) {
    MutexLock l(&mu_);

    uint64_t start = env_->NowMicros();
    while (count_ < count) {
      uint64_t now = env_->NowMicros();
87 88
      cond_count_.TimedWait(now + /*1s*/ 1 * 1000 * 1000);
      if (env_->NowMicros() - start > /*10s*/ 10 * 1000 * 1000) {
89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
        return false;
      }
      if (count_ < count) {
        GTEST_LOG_(WARNING) << "WaitFor is taking more time than usual";
      }
    }

    return true;
  }

  void Reset() {
    MutexLock l(&mu_);
    count_ = 0;
    cond_count_.SignalAll();
  }

 private:
  Env* env_;
  port::Mutex mu_;
  port::CondVar cond_count_;
  int count_;
};

struct OptionsOverride {
  std::shared_ptr<const FilterPolicy> filter_policy = nullptr;

  // Used as a bit mask of individual enums in which to skip an XF test point
  int skip_policy = 0;
};

}  // namespace anon

// Special Env used to delay background operations
class SpecialEnv : public EnvWrapper {
 public:
  explicit SpecialEnv(Env* base);

  Status NewWritableFile(const std::string& f, unique_ptr<WritableFile>* r,
                         const EnvOptions& soptions) override {
    class SSTableFile : public WritableFile {
     private:
      SpecialEnv* env_;
      unique_ptr<WritableFile> base_;

     public:
      SSTableFile(SpecialEnv* env, unique_ptr<WritableFile>&& base)
S
sdong 已提交
135
          : env_(env), base_(std::move(base)) {}
136 137 138 139 140 141 142 143 144 145 146 147 148 149
      Status Append(const Slice& data) override {
        if (env_->table_write_callback_) {
          (*env_->table_write_callback_)();
        }
        if (env_->drop_writes_.load(std::memory_order_acquire)) {
          // Drop writes on the floor
          return Status::OK();
        } else if (env_->no_space_.load(std::memory_order_acquire)) {
          return Status::IOError("No space left on device");
        } else {
          env_->bytes_written_ += data.size();
          return base_->Append(data);
        }
      }
S
sdong 已提交
150
      Status Truncate(uint64_t size) override { return base_->Truncate(size); }
151
      Status Close() override {
152 153
// SyncPoint is not supported in Released Windows Mode.
#if !(defined NDEBUG) || !defined(OS_WIN)
154 155 156 157 158
        // Check preallocation size
        // preallocation size is never passed to base file.
        size_t preallocation_size = preallocation_block_size();
        TEST_SYNC_POINT_CALLBACK("DBTestWritableFile.GetPreallocationStatus",
                                 &preallocation_size);
159
#endif  // !(defined NDEBUG) || !defined(OS_WIN)
160 161 162 163 164 165 166 167 168 169 170 171 172
        return base_->Close();
      }
      Status Flush() override { return base_->Flush(); }
      Status Sync() override {
        ++env_->sync_counter_;
        while (env_->delay_sstable_sync_.load(std::memory_order_acquire)) {
          env_->SleepForMicroseconds(100000);
        }
        return base_->Sync();
      }
      void SetIOPriority(Env::IOPriority pri) override {
        base_->SetIOPriority(pri);
      }
173 174 175
      Env::IOPriority GetIOPriority() override {
        return base_->GetIOPriority();
      }
176 177 178 179
    };
    class ManifestFile : public WritableFile {
     public:
      ManifestFile(SpecialEnv* env, unique_ptr<WritableFile>&& b)
S
sdong 已提交
180
          : env_(env), base_(std::move(b)) {}
181 182 183 184 185 186 187
      Status Append(const Slice& data) override {
        if (env_->manifest_write_error_.load(std::memory_order_acquire)) {
          return Status::IOError("simulated writer error");
        } else {
          return base_->Append(data);
        }
      }
188
      Status Truncate(uint64_t size) override { return base_->Truncate(size); }
189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209
      Status Close() override { return base_->Close(); }
      Status Flush() override { return base_->Flush(); }
      Status Sync() override {
        ++env_->sync_counter_;
        if (env_->manifest_sync_error_.load(std::memory_order_acquire)) {
          return Status::IOError("simulated sync error");
        } else {
          return base_->Sync();
        }
      }
      uint64_t GetFileSize() override { return base_->GetFileSize(); }

     private:
      SpecialEnv* env_;
      unique_ptr<WritableFile> base_;
    };
    class WalFile : public WritableFile {
     public:
      WalFile(SpecialEnv* env, unique_ptr<WritableFile>&& b)
          : env_(env), base_(std::move(b)) {}
      Status Append(const Slice& data) override {
S
sdong 已提交
210 211 212 213
#if !(defined NDEBUG) || !defined(OS_WIN)
        TEST_SYNC_POINT("SpecialEnv::WalFile::Append:1");
#endif
        Status s;
214
        if (env_->log_write_error_.load(std::memory_order_acquire)) {
S
sdong 已提交
215
          s = Status::IOError("simulated writer error");
216 217 218 219 220 221
        } else {
          int slowdown =
              env_->log_write_slowdown_.load(std::memory_order_acquire);
          if (slowdown > 0) {
            env_->SleepForMicroseconds(slowdown);
          }
S
sdong 已提交
222
          s = base_->Append(data);
223
        }
S
sdong 已提交
224 225 226 227
#if !(defined NDEBUG) || !defined(OS_WIN)
        TEST_SYNC_POINT("SpecialEnv::WalFile::Append:2");
#endif
        return s;
228
      }
229
      Status Truncate(uint64_t size) override { return base_->Truncate(size); }
230 231 232 233 234 235
      Status Close() override { return base_->Close(); }
      Status Flush() override { return base_->Flush(); }
      Status Sync() override {
        ++env_->sync_counter_;
        return base_->Sync();
      }
236 237 238
      bool IsSyncThreadSafe() const override {
        return env_->is_wal_sync_thread_safe_.load();
      }
239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282

     private:
      SpecialEnv* env_;
      unique_ptr<WritableFile> base_;
    };

    if (non_writeable_rate_.load(std::memory_order_acquire) > 0) {
      uint32_t random_number;
      {
        MutexLock l(&rnd_mutex_);
        random_number = rnd_.Uniform(100);
      }
      if (random_number < non_writeable_rate_.load()) {
        return Status::IOError("simulated random write error");
      }
    }

    new_writable_count_++;

    if (non_writable_count_.load() > 0) {
      non_writable_count_--;
      return Status::IOError("simulated write error");
    }

    Status s = target()->NewWritableFile(f, r, soptions);
    if (s.ok()) {
      if (strstr(f.c_str(), ".sst") != nullptr) {
        r->reset(new SSTableFile(this, std::move(*r)));
      } else if (strstr(f.c_str(), "MANIFEST") != nullptr) {
        r->reset(new ManifestFile(this, std::move(*r)));
      } else if (strstr(f.c_str(), "log") != nullptr) {
        r->reset(new WalFile(this, std::move(*r)));
      }
    }
    return s;
  }

  Status NewRandomAccessFile(const std::string& f,
                             unique_ptr<RandomAccessFile>* r,
                             const EnvOptions& soptions) override {
    class CountingFile : public RandomAccessFile {
     public:
      CountingFile(unique_ptr<RandomAccessFile>&& target,
                   anon::AtomicCounter* counter)
S
sdong 已提交
283
          : target_(std::move(target)), counter_(counter) {}
284 285 286 287 288 289 290 291 292 293 294 295
      virtual Status Read(uint64_t offset, size_t n, Slice* result,
                          char* scratch) const override {
        counter_->Increment();
        return target_->Read(offset, n, result, scratch);
      }

     private:
      unique_ptr<RandomAccessFile> target_;
      anon::AtomicCounter* counter_;
    };

    Status s = target()->NewRandomAccessFile(f, r, soptions);
296
    random_file_open_counter_++;
297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329
    if (s.ok() && count_random_reads_) {
      r->reset(new CountingFile(std::move(*r), &random_read_counter_));
    }
    return s;
  }

  Status NewSequentialFile(const std::string& f, unique_ptr<SequentialFile>* r,
                           const EnvOptions& soptions) override {
    class CountingFile : public SequentialFile {
     public:
      CountingFile(unique_ptr<SequentialFile>&& target,
                   anon::AtomicCounter* counter)
          : target_(std::move(target)), counter_(counter) {}
      virtual Status Read(size_t n, Slice* result, char* scratch) override {
        counter_->Increment();
        return target_->Read(n, result, scratch);
      }
      virtual Status Skip(uint64_t n) override { return target_->Skip(n); }

     private:
      unique_ptr<SequentialFile> target_;
      anon::AtomicCounter* counter_;
    };

    Status s = target()->NewSequentialFile(f, r, soptions);
    if (s.ok() && count_sequential_reads_) {
      r->reset(new CountingFile(std::move(*r), &sequential_read_counter_));
    }
    return s;
  }

  virtual void SleepForMicroseconds(int micros) override {
    sleep_counter_.Increment();
330
    if (no_sleep_ || time_elapse_only_sleep_) {
331
      addon_time_.fetch_add(micros);
332 333
    }
    if (!no_sleep_) {
334 335 336 337 338
      target()->SleepForMicroseconds(micros);
    }
  }

  virtual Status GetCurrentTime(int64_t* unix_time) override {
339 340 341 342
    Status s;
    if (!time_elapse_only_sleep_) {
      s = target()->GetCurrentTime(unix_time);
    }
343 344 345 346 347 348 349
    if (s.ok()) {
      *unix_time += addon_time_.load();
    }
    return s;
  }

  virtual uint64_t NowNanos() override {
350 351
    return (time_elapse_only_sleep_ ? 0 : target()->NowNanos()) +
           addon_time_.load() * 1000;
352 353 354
  }

  virtual uint64_t NowMicros() override {
355 356
    return (time_elapse_only_sleep_ ? 0 : target()->NowMicros()) +
           addon_time_.load();
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387
  }

  Random rnd_;
  port::Mutex rnd_mutex_;  // Lock to pretect rnd_

  // sstable Sync() calls are blocked while this pointer is non-nullptr.
  std::atomic<bool> delay_sstable_sync_;

  // Drop writes on the floor while this pointer is non-nullptr.
  std::atomic<bool> drop_writes_;

  // Simulate no-space errors while this pointer is non-nullptr.
  std::atomic<bool> no_space_;

  // Simulate non-writable file system while this pointer is non-nullptr
  std::atomic<bool> non_writable_;

  // Force sync of manifest files to fail while this pointer is non-nullptr
  std::atomic<bool> manifest_sync_error_;

  // Force write to manifest files to fail while this pointer is non-nullptr
  std::atomic<bool> manifest_write_error_;

  // Force write to log files to fail while this pointer is non-nullptr
  std::atomic<bool> log_write_error_;

  // Slow down every log write, in micro-seconds.
  std::atomic<int> log_write_slowdown_;

  bool count_random_reads_;
  anon::AtomicCounter random_read_counter_;
388
  std::atomic<int> random_file_open_counter_;
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407

  bool count_sequential_reads_;
  anon::AtomicCounter sequential_read_counter_;

  anon::AtomicCounter sleep_counter_;

  std::atomic<int64_t> bytes_written_;

  std::atomic<int> sync_counter_;

  std::atomic<uint32_t> non_writeable_rate_;

  std::atomic<uint32_t> new_writable_count_;

  std::atomic<uint32_t> non_writable_count_;

  std::function<void()>* table_write_callback_;

  std::atomic<int64_t> addon_time_;
408 409 410

  bool time_elapse_only_sleep_;

411
  bool no_sleep_;
412

S
sdong 已提交
413
  std::atomic<bool> is_wal_sync_thread_safe_{true};
414 415 416 417 418 419 420 421 422 423 424
};

class DBTestBase : public testing::Test {
 protected:
  // Sequence of option configurations to try
  enum OptionConfig {
    kDefault = 0,
    kBlockBasedTableWithPrefixHashIndex = 1,
    kBlockBasedTableWithWholeKeyHashIndex = 2,
    kPlainTableFirstBytePrefix = 3,
    kPlainTableCappedPrefix = 4,
425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448
    kPlainTableCappedPrefixNonMmap = 5,
    kPlainTableAllBytesPrefix = 6,
    kVectorRep = 7,
    kHashLinkList = 8,
    kHashCuckoo = 9,
    kMergePut = 10,
    kFilter = 11,
    kFullFilterWithNewTableReaderForCompactions = 12,
    kUncompressed = 13,
    kNumLevel_3 = 14,
    kDBLogDir = 15,
    kWalDirAndMmapReads = 16,
    kManifestFileSize = 17,
    kPerfOptions = 18,
    kDeletesFilterFirst = 19,
    kHashSkipList = 20,
    kUniversalCompaction = 21,
    kUniversalCompactionMultiLevel = 22,
    kCompressedBlockCache = 23,
    kInfiniteMaxOpenFiles = 24,
    kxxHashChecksum = 25,
    kFIFOCompaction = 26,
    kOptimizeFiltersForHits = 27,
    kRowCache = 28,
449 450 451 452
    kRecycleLogFiles = 29,
    kLevelSubcompactions = 30,
    kUniversalSubcompactions = 31,
    kEnd = 30
453 454 455 456 457 458
  };
  int option_config_;

 public:
  std::string dbname_;
  std::string alternative_wal_dir_;
S
sdong 已提交
459
  std::string alternative_db_log_dir_;
460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485
  MockEnv* mem_env_;
  SpecialEnv* env_;
  DB* db_;
  std::vector<ColumnFamilyHandle*> handles_;

  Options last_options_;

  // Skip some options, as they may not be applicable to a specific test.
  // To add more skip constants, use values 4, 8, 16, etc.
  enum OptionSkip {
    kNoSkip = 0,
    kSkipDeletesFilterFirst = 1,
    kSkipUniversalCompaction = 2,
    kSkipMergePut = 4,
    kSkipPlainTable = 8,
    kSkipHashIndex = 16,
    kSkipNoSeekToLast = 32,
    kSkipHashCuckoo = 64,
    kSkipFIFOCompaction = 128,
    kSkipMmapReads = 256,
  };

  explicit DBTestBase(const std::string path);

  ~DBTestBase();

486 487 488 489 490 491 492 493 494 495 496 497
  static std::string RandomString(Random* rnd, int len) {
    std::string r;
    test::RandomString(rnd, len, &r);
    return r;
  }

  static std::string Key(int i) {
    char buf[100];
    snprintf(buf, sizeof(buf), "key%06d", i);
    return std::string(buf);
  }

498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516
  // Switch to a fresh database with the next option configuration to
  // test.  Return false if there are no more configurations to test.
  bool ChangeOptions(int skip_mask = kNoSkip);

  // Switch between different compaction styles (we have only 2 now).
  bool ChangeCompactOptions();

  // Switch between different filter policy
  // Jump from kDefault to kFilter to kFullFilter
  bool ChangeFilterOptions();

  // Return the current option configuration.
  Options CurrentOptions(
      const anon::OptionsOverride& options_override = anon::OptionsOverride());

  Options CurrentOptions(
      const Options& defaultOptions,
      const anon::OptionsOverride& options_override = anon::OptionsOverride());

S
sdong 已提交
517
  DBImpl* dbfull() { return reinterpret_cast<DBImpl*>(db_); }
518 519 520 521 522 523 524 525 526 527 528 529 530

  void CreateColumnFamilies(const std::vector<std::string>& cfs,
                            const Options& options);

  void CreateAndReopenWithCF(const std::vector<std::string>& cfs,
                             const Options& options);

  void ReopenWithColumnFamilies(const std::vector<std::string>& cfs,
                                const std::vector<Options>& options);

  void ReopenWithColumnFamilies(const std::vector<std::string>& cfs,
                                const Options& options);

S
sdong 已提交
531 532
  Status TryReopenWithColumnFamilies(const std::vector<std::string>& cfs,
                                     const std::vector<Options>& options);
533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559

  Status TryReopenWithColumnFamilies(const std::vector<std::string>& cfs,
                                     const Options& options);

  void Reopen(const Options& options);

  void Close();

  void DestroyAndReopen(const Options& options);

  void Destroy(const Options& options);

  Status ReadOnlyReopen(const Options& options);

  Status TryReopen(const Options& options);

  Status Flush(int cf = 0);

  Status Put(const Slice& k, const Slice& v, WriteOptions wo = WriteOptions());

  Status Put(int cf, const Slice& k, const Slice& v,
             WriteOptions wo = WriteOptions());

  Status Delete(const std::string& k);

  Status Delete(int cf, const std::string& k);

A
Andres Noetzli 已提交
560 561 562 563
  Status SingleDelete(const std::string& k);

  Status SingleDelete(int cf, const std::string& k);

564 565 566 567 568 569 570 571 572 573 574 575 576 577 578
  std::string Get(const std::string& k, const Snapshot* snapshot = nullptr);

  std::string Get(int cf, const std::string& k,
                  const Snapshot* snapshot = nullptr);

  uint64_t GetNumSnapshots();

  uint64_t GetTimeOldestSnapshots();

  // Return a string that contains all key,value pairs in order,
  // formatted like "(k1->v1)(k2->v2)".
  std::string Contents(int cf = 0);

  std::string AllEntriesFor(const Slice& user_key, int cf = 0);

579
#ifndef ROCKSDB_LITE
580 581 582 583 584 585 586 587
  int NumSortedRuns(int cf = 0);

  uint64_t TotalSize(int cf = 0);

  uint64_t SizeAtLevel(int level);

  int TotalLiveFiles(int cf = 0);

588 589 590 591 592
  size_t CountLiveFiles();
#endif  // ROCKSDB_LITE

  int NumTableFilesAtLevel(int level, int cf = 0);

593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618
  int TotalTableFiles(int cf = 0, int levels = -1);

  // Return spread of files per level
  std::string FilesPerLevel(int cf = 0);

  size_t CountFiles();

  uint64_t Size(const Slice& start, const Slice& limit, int cf = 0);

  void Compact(int cf, const Slice& start, const Slice& limit,
               uint32_t target_path_id);

  void Compact(int cf, const Slice& start, const Slice& limit);

  void Compact(const Slice& start, const Slice& limit);

  // Do n memtable compactions, each of which produces an sstable
  // covering the range [small,large].
  void MakeTables(int n, const std::string& small, const std::string& large,
                  int cf = 0);

  // Prevent pushing of new sstables into deeper levels by adding
  // tables that cover a specified range to all levels.
  void FillLevels(const std::string& smallest, const std::string& largest,
                  int cf);

619 620
  void MoveFilesToLevel(int level, int cf = 0);

621 622 623 624
  void DumpFileCounts(const char* label);

  std::string DumpSSTableList();

D
dyniusz 已提交
625 626
  void GetSstFiles(std::string path, std::vector<std::string>* files);

627 628 629 630 631
  int GetSstFileCount(std::string path);

  // this will generate non-overlapping files since it keeps increasing key_idx
  void GenerateNewFile(Random* rnd, int* key_idx, bool nowait = false);

632 633
  void GenerateNewFile(int fd, Random* rnd, int* key_idx, bool nowait = false);

634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649
  void GenerateNewRandomFile(Random* rnd, bool nowait = false);

  std::string IterStatus(Iterator* iter);

  Options OptionsForLogIterTest();

  std::string DummyString(size_t len, char c = 'a');

  void VerifyIterLast(std::string expected_key, int cf = 0);

  // Used to test InplaceUpdate

  // If previous value is nullptr or delta is > than previous value,
  //   sets newValue with delta
  // If previous value is not empty,
  //   updates previous value with 'b' string of previous value size - 1.
S
sdong 已提交
650 651 652
  static UpdateStatus updateInPlaceSmallerSize(char* prevValue,
                                               uint32_t* prevSize, Slice delta,
                                               std::string* newValue);
653

S
sdong 已提交
654 655 656 657
  static UpdateStatus updateInPlaceSmallerVarintSize(char* prevValue,
                                                     uint32_t* prevSize,
                                                     Slice delta,
                                                     std::string* newValue);
658

S
sdong 已提交
659 660 661
  static UpdateStatus updateInPlaceLargerSize(char* prevValue,
                                              uint32_t* prevSize, Slice delta,
                                              std::string* newValue);
662

S
sdong 已提交
663 664
  static UpdateStatus updateInPlaceNoAction(char* prevValue, uint32_t* prevSize,
                                            Slice delta, std::string* newValue);
665 666 667 668 669 670 671 672 673

  // Utility method to test InplaceUpdate
  void validateNumberOfEntries(int numValues, int cf = 0);

  void CopyFile(const std::string& source, const std::string& destination,
                uint64_t size = 0);
};

}  // namespace rocksdb