summaryrefslogtreecommitdiffstats
path: root/src/rocksdb/utilities/write_batch_with_index/write_batch_with_index.cc
blob: 408243b3fff47752a9ef740ac453468b734645de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
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
87
88
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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
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
283
284
285
286
287
288
289
290
291
292
293
294
295
296
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
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
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
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
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
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
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
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
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
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).

#ifndef ROCKSDB_LITE

#include "rocksdb/utilities/write_batch_with_index.h"

#include <memory>

#include "db/column_family.h"
#include "db/db_impl/db_impl.h"
#include "db/merge_context.h"
#include "db/merge_helper.h"
#include "memory/arena.h"
#include "memtable/skiplist.h"
#include "options/db_options.h"
#include "rocksdb/comparator.h"
#include "rocksdb/iterator.h"
#include "util/cast_util.h"
#include "util/string_util.h"
#include "utilities/write_batch_with_index/write_batch_with_index_internal.h"

namespace ROCKSDB_NAMESPACE {
struct WriteBatchWithIndex::Rep {
  explicit Rep(const Comparator* index_comparator, size_t reserved_bytes = 0,
               size_t max_bytes = 0, bool _overwrite_key = false,
               size_t protection_bytes_per_key = 0)
      : write_batch(reserved_bytes, max_bytes, protection_bytes_per_key,
                    index_comparator ? index_comparator->timestamp_size() : 0),
        comparator(index_comparator, &write_batch),
        skip_list(comparator, &arena),
        overwrite_key(_overwrite_key),
        last_entry_offset(0),
        last_sub_batch_offset(0),
        sub_batch_cnt(1) {}
  ReadableWriteBatch write_batch;
  WriteBatchEntryComparator comparator;
  Arena arena;
  WriteBatchEntrySkipList skip_list;
  bool overwrite_key;
  size_t last_entry_offset;
  // The starting offset of the last sub-batch. A sub-batch starts right before
  // inserting a key that is a duplicate of a key in the last sub-batch. Zero,
  // the default, means that no duplicate key is detected so far.
  size_t last_sub_batch_offset;
  // Total number of sub-batches in the write batch. Default is 1.
  size_t sub_batch_cnt;

  // Remember current offset of internal write batch, which is used as
  // the starting offset of the next record.
  void SetLastEntryOffset() { last_entry_offset = write_batch.GetDataSize(); }

  // In overwrite mode, find the existing entry for the same key and update it
  // to point to the current entry.
  // Return true if the key is found and updated.
  bool UpdateExistingEntry(ColumnFamilyHandle* column_family, const Slice& key,
                           WriteType type);
  bool UpdateExistingEntryWithCfId(uint32_t column_family_id, const Slice& key,
                                   WriteType type);

  // Add the recent entry to the update.
  // In overwrite mode, if key already exists in the index, update it.
  void AddOrUpdateIndex(ColumnFamilyHandle* column_family, const Slice& key,
                        WriteType type);
  void AddOrUpdateIndex(const Slice& key, WriteType type);

  // Allocate an index entry pointing to the last entry in the write batch and
  // put it to skip list.
  void AddNewEntry(uint32_t column_family_id);

  // Clear all updates buffered in this batch.
  void Clear();
  void ClearIndex();

  // Rebuild index by reading all records from the batch.
  // Returns non-ok status on corruption.
  Status ReBuildIndex();
};

bool WriteBatchWithIndex::Rep::UpdateExistingEntry(
    ColumnFamilyHandle* column_family, const Slice& key, WriteType type) {
  uint32_t cf_id = GetColumnFamilyID(column_family);
  return UpdateExistingEntryWithCfId(cf_id, key, type);
}

bool WriteBatchWithIndex::Rep::UpdateExistingEntryWithCfId(
    uint32_t column_family_id, const Slice& key, WriteType type) {
  if (!overwrite_key) {
    return false;
  }

  WBWIIteratorImpl iter(column_family_id, &skip_list, &write_batch,
                        &comparator);
  iter.Seek(key);
  if (!iter.Valid()) {
    return false;
  } else if (!iter.MatchesKey(column_family_id, key)) {
    return false;
  } else {
    // Move to the end of this key (NextKey-Prev)
    iter.NextKey();  // Move to the next key
    if (iter.Valid()) {
      iter.Prev();  // Move back one entry
    } else {
      iter.SeekToLast();
    }
  }
  WriteBatchIndexEntry* non_const_entry =
      const_cast<WriteBatchIndexEntry*>(iter.GetRawEntry());
  if (LIKELY(last_sub_batch_offset <= non_const_entry->offset)) {
    last_sub_batch_offset = last_entry_offset;
    sub_batch_cnt++;
  }
  if (type == kMergeRecord) {
    return false;
  } else {
    non_const_entry->offset = last_entry_offset;
    return true;
  }
}

void WriteBatchWithIndex::Rep::AddOrUpdateIndex(
    ColumnFamilyHandle* column_family, const Slice& key, WriteType type) {
  if (!UpdateExistingEntry(column_family, key, type)) {
    uint32_t cf_id = GetColumnFamilyID(column_family);
    const auto* cf_cmp = GetColumnFamilyUserComparator(column_family);
    if (cf_cmp != nullptr) {
      comparator.SetComparatorForCF(cf_id, cf_cmp);
    }
    AddNewEntry(cf_id);
  }
}

void WriteBatchWithIndex::Rep::AddOrUpdateIndex(const Slice& key,
                                                WriteType type) {
  if (!UpdateExistingEntryWithCfId(0, key, type)) {
    AddNewEntry(0);
  }
}

void WriteBatchWithIndex::Rep::AddNewEntry(uint32_t column_family_id) {
  const std::string& wb_data = write_batch.Data();
  Slice entry_ptr = Slice(wb_data.data() + last_entry_offset,
                          wb_data.size() - last_entry_offset);
  // Extract key
  Slice key;
  bool success =
      ReadKeyFromWriteBatchEntry(&entry_ptr, &key, column_family_id != 0);
#ifdef NDEBUG
  (void)success;
#endif
  assert(success);

  const Comparator* const ucmp = comparator.GetComparator(column_family_id);
  size_t ts_sz = ucmp ? ucmp->timestamp_size() : 0;

  if (ts_sz > 0) {
    key.remove_suffix(ts_sz);
  }

  auto* mem = arena.Allocate(sizeof(WriteBatchIndexEntry));
  auto* index_entry =
      new (mem) WriteBatchIndexEntry(last_entry_offset, column_family_id,
                                     key.data() - wb_data.data(), key.size());
  skip_list.Insert(index_entry);
}

void WriteBatchWithIndex::Rep::Clear() {
  write_batch.Clear();
  ClearIndex();
}

void WriteBatchWithIndex::Rep::ClearIndex() {
  skip_list.~WriteBatchEntrySkipList();
  arena.~Arena();
  new (&arena) Arena();
  new (&skip_list) WriteBatchEntrySkipList(comparator, &arena);
  last_entry_offset = 0;
  last_sub_batch_offset = 0;
  sub_batch_cnt = 1;
}

Status WriteBatchWithIndex::Rep::ReBuildIndex() {
  Status s;

  ClearIndex();

  if (write_batch.Count() == 0) {
    // Nothing to re-index
    return s;
  }

  size_t offset = WriteBatchInternal::GetFirstOffset(&write_batch);

  Slice input(write_batch.Data());
  input.remove_prefix(offset);

  // Loop through all entries in Rep and add each one to the index
  uint32_t found = 0;
  while (s.ok() && !input.empty()) {
    Slice key, value, blob, xid;
    uint32_t column_family_id = 0;  // default
    char tag = 0;

    // set offset of current entry for call to AddNewEntry()
    last_entry_offset = input.data() - write_batch.Data().data();

    s = ReadRecordFromWriteBatch(&input, &tag, &column_family_id, &key, &value,
                                 &blob, &xid);
    if (!s.ok()) {
      break;
    }

    switch (tag) {
      case kTypeColumnFamilyValue:
      case kTypeValue:
        found++;
        if (!UpdateExistingEntryWithCfId(column_family_id, key, kPutRecord)) {
          AddNewEntry(column_family_id);
        }
        break;
      case kTypeColumnFamilyDeletion:
      case kTypeDeletion:
        found++;
        if (!UpdateExistingEntryWithCfId(column_family_id, key,
                                         kDeleteRecord)) {
          AddNewEntry(column_family_id);
        }
        break;
      case kTypeColumnFamilySingleDeletion:
      case kTypeSingleDeletion:
        found++;
        if (!UpdateExistingEntryWithCfId(column_family_id, key,
                                         kSingleDeleteRecord)) {
          AddNewEntry(column_family_id);
        }
        break;
      case kTypeColumnFamilyMerge:
      case kTypeMerge:
        found++;
        if (!UpdateExistingEntryWithCfId(column_family_id, key, kMergeRecord)) {
          AddNewEntry(column_family_id);
        }
        break;
      case kTypeLogData:
      case kTypeBeginPrepareXID:
      case kTypeBeginPersistedPrepareXID:
      case kTypeBeginUnprepareXID:
      case kTypeEndPrepareXID:
      case kTypeCommitXID:
      case kTypeCommitXIDAndTimestamp:
      case kTypeRollbackXID:
      case kTypeNoop:
        break;
      default:
        return Status::Corruption(
            "unknown WriteBatch tag in ReBuildIndex",
            std::to_string(static_cast<unsigned int>(tag)));
    }
  }

  if (s.ok() && found != write_batch.Count()) {
    s = Status::Corruption("WriteBatch has wrong count");
  }

  return s;
}

WriteBatchWithIndex::WriteBatchWithIndex(
    const Comparator* default_index_comparator, size_t reserved_bytes,
    bool overwrite_key, size_t max_bytes, size_t protection_bytes_per_key)
    : rep(new Rep(default_index_comparator, reserved_bytes, max_bytes,
                  overwrite_key, protection_bytes_per_key)) {}

WriteBatchWithIndex::~WriteBatchWithIndex() {}

WriteBatchWithIndex::WriteBatchWithIndex(WriteBatchWithIndex&&) = default;

WriteBatchWithIndex& WriteBatchWithIndex::operator=(WriteBatchWithIndex&&) =
    default;

WriteBatch* WriteBatchWithIndex::GetWriteBatch() { return &rep->write_batch; }

size_t WriteBatchWithIndex::SubBatchCnt() { return rep->sub_batch_cnt; }

WBWIIterator* WriteBatchWithIndex::NewIterator() {
  return new WBWIIteratorImpl(0, &(rep->skip_list), &rep->write_batch,
                              &(rep->comparator));
}

WBWIIterator* WriteBatchWithIndex::NewIterator(
    ColumnFamilyHandle* column_family) {
  return new WBWIIteratorImpl(GetColumnFamilyID(column_family),
                              &(rep->skip_list), &rep->write_batch,
                              &(rep->comparator));
}

Iterator* WriteBatchWithIndex::NewIteratorWithBase(
    ColumnFamilyHandle* column_family, Iterator* base_iterator,
    const ReadOptions* read_options) {
  auto wbwiii =
      new WBWIIteratorImpl(GetColumnFamilyID(column_family), &(rep->skip_list),
                           &rep->write_batch, &rep->comparator);
  return new BaseDeltaIterator(column_family, base_iterator, wbwiii,
                               GetColumnFamilyUserComparator(column_family),
                               read_options);
}

Iterator* WriteBatchWithIndex::NewIteratorWithBase(Iterator* base_iterator) {
  // default column family's comparator
  auto wbwiii = new WBWIIteratorImpl(0, &(rep->skip_list), &rep->write_batch,
                                     &rep->comparator);
  return new BaseDeltaIterator(nullptr, base_iterator, wbwiii,
                               rep->comparator.default_comparator());
}

Status WriteBatchWithIndex::Put(ColumnFamilyHandle* column_family,
                                const Slice& key, const Slice& value) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.Put(column_family, key, value);
  if (s.ok()) {
    rep->AddOrUpdateIndex(column_family, key, kPutRecord);
  }
  return s;
}

Status WriteBatchWithIndex::Put(const Slice& key, const Slice& value) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.Put(key, value);
  if (s.ok()) {
    rep->AddOrUpdateIndex(key, kPutRecord);
  }
  return s;
}

Status WriteBatchWithIndex::Put(ColumnFamilyHandle* column_family,
                                const Slice& /*key*/, const Slice& /*ts*/,
                                const Slice& /*value*/) {
  if (!column_family) {
    return Status::InvalidArgument("column family handle cannot be nullptr");
  }
  // TODO: support WBWI::Put() with timestamp.
  return Status::NotSupported();
}

Status WriteBatchWithIndex::Delete(ColumnFamilyHandle* column_family,
                                   const Slice& key) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.Delete(column_family, key);
  if (s.ok()) {
    rep->AddOrUpdateIndex(column_family, key, kDeleteRecord);
  }
  return s;
}

Status WriteBatchWithIndex::Delete(const Slice& key) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.Delete(key);
  if (s.ok()) {
    rep->AddOrUpdateIndex(key, kDeleteRecord);
  }
  return s;
}

Status WriteBatchWithIndex::Delete(ColumnFamilyHandle* column_family,
                                   const Slice& /*key*/, const Slice& /*ts*/) {
  if (!column_family) {
    return Status::InvalidArgument("column family handle cannot be nullptr");
  }
  // TODO: support WBWI::Delete() with timestamp.
  return Status::NotSupported();
}

Status WriteBatchWithIndex::SingleDelete(ColumnFamilyHandle* column_family,
                                         const Slice& key) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.SingleDelete(column_family, key);
  if (s.ok()) {
    rep->AddOrUpdateIndex(column_family, key, kSingleDeleteRecord);
  }
  return s;
}

Status WriteBatchWithIndex::SingleDelete(const Slice& key) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.SingleDelete(key);
  if (s.ok()) {
    rep->AddOrUpdateIndex(key, kSingleDeleteRecord);
  }
  return s;
}

Status WriteBatchWithIndex::SingleDelete(ColumnFamilyHandle* column_family,
                                         const Slice& /*key*/,
                                         const Slice& /*ts*/) {
  if (!column_family) {
    return Status::InvalidArgument("column family handle cannot be nullptr");
  }
  // TODO: support WBWI::SingleDelete() with timestamp.
  return Status::NotSupported();
}

Status WriteBatchWithIndex::Merge(ColumnFamilyHandle* column_family,
                                  const Slice& key, const Slice& value) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.Merge(column_family, key, value);
  if (s.ok()) {
    rep->AddOrUpdateIndex(column_family, key, kMergeRecord);
  }
  return s;
}

Status WriteBatchWithIndex::Merge(const Slice& key, const Slice& value) {
  rep->SetLastEntryOffset();
  auto s = rep->write_batch.Merge(key, value);
  if (s.ok()) {
    rep->AddOrUpdateIndex(key, kMergeRecord);
  }
  return s;
}

Status WriteBatchWithIndex::PutLogData(const Slice& blob) {
  return rep->write_batch.PutLogData(blob);
}

void WriteBatchWithIndex::Clear() { rep->Clear(); }

Status WriteBatchWithIndex::GetFromBatch(ColumnFamilyHandle* column_family,
                                         const DBOptions& options,
                                         const Slice& key, std::string* value) {
  Status s;
  WriteBatchWithIndexInternal wbwii(&options, column_family);
  auto result = wbwii.GetFromBatch(this, key, value, &s);

  switch (result) {
    case WBWIIteratorImpl::kFound:
    case WBWIIteratorImpl::kError:
      // use returned status
      break;
    case WBWIIteratorImpl::kDeleted:
    case WBWIIteratorImpl::kNotFound:
      s = Status::NotFound();
      break;
    case WBWIIteratorImpl::kMergeInProgress:
      s = Status::MergeInProgress();
      break;
    default:
      assert(false);
  }

  return s;
}

Status WriteBatchWithIndex::GetFromBatchAndDB(DB* db,
                                              const ReadOptions& read_options,
                                              const Slice& key,
                                              std::string* value) {
  assert(value != nullptr);
  PinnableSlice pinnable_val(value);
  assert(!pinnable_val.IsPinned());
  auto s = GetFromBatchAndDB(db, read_options, db->DefaultColumnFamily(), key,
                             &pinnable_val);
  if (s.ok() && pinnable_val.IsPinned()) {
    value->assign(pinnable_val.data(), pinnable_val.size());
  }  // else value is already assigned
  return s;
}

Status WriteBatchWithIndex::GetFromBatchAndDB(DB* db,
                                              const ReadOptions& read_options,
                                              const Slice& key,
                                              PinnableSlice* pinnable_val) {
  return GetFromBatchAndDB(db, read_options, db->DefaultColumnFamily(), key,
                           pinnable_val);
}

Status WriteBatchWithIndex::GetFromBatchAndDB(DB* db,
                                              const ReadOptions& read_options,
                                              ColumnFamilyHandle* column_family,
                                              const Slice& key,
                                              std::string* value) {
  assert(value != nullptr);
  PinnableSlice pinnable_val(value);
  assert(!pinnable_val.IsPinned());
  auto s =
      GetFromBatchAndDB(db, read_options, column_family, key, &pinnable_val);
  if (s.ok() && pinnable_val.IsPinned()) {
    value->assign(pinnable_val.data(), pinnable_val.size());
  }  // else value is already assigned
  return s;
}

Status WriteBatchWithIndex::GetFromBatchAndDB(DB* db,
                                              const ReadOptions& read_options,
                                              ColumnFamilyHandle* column_family,
                                              const Slice& key,
                                              PinnableSlice* pinnable_val) {
  return GetFromBatchAndDB(db, read_options, column_family, key, pinnable_val,
                           nullptr);
}

Status WriteBatchWithIndex::GetFromBatchAndDB(
    DB* db, const ReadOptions& read_options, ColumnFamilyHandle* column_family,
    const Slice& key, PinnableSlice* pinnable_val, ReadCallback* callback) {
  const Comparator* const ucmp = rep->comparator.GetComparator(column_family);
  size_t ts_sz = ucmp ? ucmp->timestamp_size() : 0;
  if (ts_sz > 0 && !read_options.timestamp) {
    return Status::InvalidArgument("Must specify timestamp");
  }

  Status s;
  WriteBatchWithIndexInternal wbwii(db, column_family);

  // Since the lifetime of the WriteBatch is the same as that of the transaction
  // we cannot pin it as otherwise the returned value will not be available
  // after the transaction finishes.
  std::string& batch_value = *pinnable_val->GetSelf();
  auto result = wbwii.GetFromBatch(this, key, &batch_value, &s);

  if (result == WBWIIteratorImpl::kFound) {
    pinnable_val->PinSelf();
    return s;
  } else if (!s.ok() || result == WBWIIteratorImpl::kError) {
    return s;
  } else if (result == WBWIIteratorImpl::kDeleted) {
    return Status::NotFound();
  }
  assert(result == WBWIIteratorImpl::kMergeInProgress ||
         result == WBWIIteratorImpl::kNotFound);

  // Did not find key in batch OR could not resolve Merges.  Try DB.
  if (!callback) {
    s = db->Get(read_options, column_family, key, pinnable_val);
  } else {
    DBImpl::GetImplOptions get_impl_options;
    get_impl_options.column_family = column_family;
    get_impl_options.value = pinnable_val;
    get_impl_options.callback = callback;
    s = static_cast_with_check<DBImpl>(db->GetRootDB())
            ->GetImpl(read_options, key, get_impl_options);
  }

  if (s.ok() || s.IsNotFound()) {  // DB Get Succeeded
    if (result == WBWIIteratorImpl::kMergeInProgress) {
      // Merge result from DB with merges in Batch
      std::string merge_result;
      if (s.ok()) {
        s = wbwii.MergeKey(key, pinnable_val, &merge_result);
      } else {  // Key not present in db (s.IsNotFound())
        s = wbwii.MergeKey(key, nullptr, &merge_result);
      }
      if (s.ok()) {
        pinnable_val->Reset();
        *pinnable_val->GetSelf() = std::move(merge_result);
        pinnable_val->PinSelf();
      }
    }
  }

  return s;
}

void WriteBatchWithIndex::MultiGetFromBatchAndDB(
    DB* db, const ReadOptions& read_options, ColumnFamilyHandle* column_family,
    const size_t num_keys, const Slice* keys, PinnableSlice* values,
    Status* statuses, bool sorted_input) {
  MultiGetFromBatchAndDB(db, read_options, column_family, num_keys, keys,
                         values, statuses, sorted_input, nullptr);
}

void WriteBatchWithIndex::MultiGetFromBatchAndDB(
    DB* db, const ReadOptions& read_options, ColumnFamilyHandle* column_family,
    const size_t num_keys, const Slice* keys, PinnableSlice* values,
    Status* statuses, bool sorted_input, ReadCallback* callback) {
  const Comparator* const ucmp = rep->comparator.GetComparator(column_family);
  size_t ts_sz = ucmp ? ucmp->timestamp_size() : 0;
  if (ts_sz > 0 && !read_options.timestamp) {
    for (size_t i = 0; i < num_keys; ++i) {
      statuses[i] = Status::InvalidArgument("Must specify timestamp");
    }
    return;
  }

  WriteBatchWithIndexInternal wbwii(db, column_family);

  autovector<KeyContext, MultiGetContext::MAX_BATCH_SIZE> key_context;
  autovector<KeyContext*, MultiGetContext::MAX_BATCH_SIZE> sorted_keys;
  // To hold merges from the write batch
  autovector<std::pair<WBWIIteratorImpl::Result, MergeContext>,
             MultiGetContext::MAX_BATCH_SIZE>
      merges;
  // Since the lifetime of the WriteBatch is the same as that of the transaction
  // we cannot pin it as otherwise the returned value will not be available
  // after the transaction finishes.
  for (size_t i = 0; i < num_keys; ++i) {
    MergeContext merge_context;
    std::string batch_value;
    Status* s = &statuses[i];
    PinnableSlice* pinnable_val = &values[i];
    pinnable_val->Reset();
    auto result =
        wbwii.GetFromBatch(this, keys[i], &merge_context, &batch_value, s);

    if (result == WBWIIteratorImpl::kFound) {
      *pinnable_val->GetSelf() = std::move(batch_value);
      pinnable_val->PinSelf();
      continue;
    }
    if (result == WBWIIteratorImpl::kDeleted) {
      *s = Status::NotFound();
      continue;
    }
    if (result == WBWIIteratorImpl::kError) {
      continue;
    }
    assert(result == WBWIIteratorImpl::kMergeInProgress ||
           result == WBWIIteratorImpl::kNotFound);
    key_context.emplace_back(column_family, keys[i], &values[i],
                             /*timestamp*/ nullptr, &statuses[i]);
    merges.emplace_back(result, std::move(merge_context));
  }

  for (KeyContext& key : key_context) {
    sorted_keys.emplace_back(&key);
  }

  // Did not find key in batch OR could not resolve Merges.  Try DB.
  static_cast_with_check<DBImpl>(db->GetRootDB())
      ->PrepareMultiGetKeys(key_context.size(), sorted_input, &sorted_keys);
  static_cast_with_check<DBImpl>(db->GetRootDB())
      ->MultiGetWithCallback(read_options, column_family, callback,
                             &sorted_keys);

  for (auto iter = key_context.begin(); iter != key_context.end(); ++iter) {
    KeyContext& key = *iter;
    if (key.s->ok() || key.s->IsNotFound()) {  // DB Get Succeeded
      size_t index = iter - key_context.begin();
      std::pair<WBWIIteratorImpl::Result, MergeContext>& merge_result =
          merges[index];
      if (merge_result.first == WBWIIteratorImpl::kMergeInProgress) {
        std::string merged_value;
        // Merge result from DB with merges in Batch
        if (key.s->ok()) {
          *key.s = wbwii.MergeKey(*key.key, iter->value, merge_result.second,
                                  &merged_value);
        } else {  // Key not present in db (s.IsNotFound())
          *key.s = wbwii.MergeKey(*key.key, nullptr, merge_result.second,
                                  &merged_value);
        }
        if (key.s->ok()) {
          key.value->Reset();
          *key.value->GetSelf() = std::move(merged_value);
          key.value->PinSelf();
        }
      }
    }
  }
}

void WriteBatchWithIndex::SetSavePoint() { rep->write_batch.SetSavePoint(); }

Status WriteBatchWithIndex::RollbackToSavePoint() {
  Status s = rep->write_batch.RollbackToSavePoint();

  if (s.ok()) {
    rep->sub_batch_cnt = 1;
    rep->last_sub_batch_offset = 0;
    s = rep->ReBuildIndex();
  }

  return s;
}

Status WriteBatchWithIndex::PopSavePoint() {
  return rep->write_batch.PopSavePoint();
}

void WriteBatchWithIndex::SetMaxBytes(size_t max_bytes) {
  rep->write_batch.SetMaxBytes(max_bytes);
}

size_t WriteBatchWithIndex::GetDataSize() const {
  return rep->write_batch.GetDataSize();
}

const Comparator* WriteBatchWithIndexInternal::GetUserComparator(
    const WriteBatchWithIndex& wbwi, uint32_t cf_id) {
  const WriteBatchEntryComparator& ucmps = wbwi.rep->comparator;
  return ucmps.GetComparator(cf_id);
}

}  // namespace ROCKSDB_NAMESPACE
#endif  // !ROCKSDB_LITE