1 files changed, 512 insertions, 0 deletions
diff --git a/src/rocksdb/utilities/transactions/write_prepared_txn.cc b/src/rocksdb/utilities/transactions/write_prepared_txn.cc
new file mode 100644
index 000000000..16b5cc1cb
--- /dev/null
+++ b/src/rocksdb/utilities/transactions/write_prepared_txn.cc
@@ -0,0 +1,512 @@
+//  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 "utilities/transactions/write_prepared_txn.h"
+
+#include <cinttypes>
+#include <map>
+#include <set>
+
+#include "db/column_family.h"
+#include "db/db_impl/db_impl.h"
+#include "rocksdb/db.h"
+#include "rocksdb/status.h"
+#include "rocksdb/utilities/transaction_db.h"
+#include "util/cast_util.h"
+#include "utilities/transactions/pessimistic_transaction.h"
+#include "utilities/transactions/write_prepared_txn_db.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+struct WriteOptions;
+
+WritePreparedTxn::WritePreparedTxn(WritePreparedTxnDB* txn_db,
+                                   const WriteOptions& write_options,
+                                   const TransactionOptions& txn_options)
+    : PessimisticTransaction(txn_db, write_options, txn_options, false),
+      wpt_db_(txn_db) {
+  // Call Initialize outside PessimisticTransaction constructor otherwise it
+  // would skip overridden functions in WritePreparedTxn since they are not
+  // defined yet in the constructor of PessimisticTransaction
+  Initialize(txn_options);
+}
+
+void WritePreparedTxn::Initialize(const TransactionOptions& txn_options) {
+  PessimisticTransaction::Initialize(txn_options);
+  prepare_batch_cnt_ = 0;
+}
+
+void WritePreparedTxn::MultiGet(const ReadOptions& options,
+                                ColumnFamilyHandle* column_family,
+                                const size_t num_keys, const Slice* keys,
+                                PinnableSlice* values, Status* statuses,
+                                const bool sorted_input) {
+  SequenceNumber min_uncommitted, snap_seq;
+  const SnapshotBackup backed_by_snapshot =
+      wpt_db_->AssignMinMaxSeqs(options.snapshot, &min_uncommitted, &snap_seq);
+  WritePreparedTxnReadCallback callback(wpt_db_, snap_seq, min_uncommitted,
+                                        backed_by_snapshot);
+  write_batch_.MultiGetFromBatchAndDB(db_, options, column_family, num_keys,
+                                      keys, values, statuses, sorted_input,
+                                      &callback);
+  if (UNLIKELY(!callback.valid() ||
+               !wpt_db_->ValidateSnapshot(snap_seq, backed_by_snapshot))) {
+    wpt_db_->WPRecordTick(TXN_GET_TRY_AGAIN);
+    for (size_t i = 0; i < num_keys; i++) {
+      statuses[i] = Status::TryAgain();
+    }
+  }
+}
+
+Status WritePreparedTxn::Get(const ReadOptions& options,
+                             ColumnFamilyHandle* column_family,
+                             const Slice& key, PinnableSlice* pinnable_val) {
+  SequenceNumber min_uncommitted, snap_seq;
+  const SnapshotBackup backed_by_snapshot =
+      wpt_db_->AssignMinMaxSeqs(options.snapshot, &min_uncommitted, &snap_seq);
+  WritePreparedTxnReadCallback callback(wpt_db_, snap_seq, min_uncommitted,
+                                        backed_by_snapshot);
+  Status res = write_batch_.GetFromBatchAndDB(db_, options, column_family, key,
+                                              pinnable_val, &callback);
+  const bool callback_valid =
+      callback.valid();  // NOTE: validity of callback must always be checked
+                         // before it is destructed
+  if (res.ok()) {
+    if (!LIKELY(callback_valid &&
+                wpt_db_->ValidateSnapshot(callback.max_visible_seq(),
+                                          backed_by_snapshot))) {
+      wpt_db_->WPRecordTick(TXN_GET_TRY_AGAIN);
+      res = Status::TryAgain();
+    }
+  }
+
+  return res;
+}
+
+Iterator* WritePreparedTxn::GetIterator(const ReadOptions& options) {
+  // Make sure to get iterator from WritePrepareTxnDB, not the root db.
+  Iterator* db_iter = wpt_db_->NewIterator(options);
+  assert(db_iter);
+
+  return write_batch_.NewIteratorWithBase(db_iter);
+}
+
+Iterator* WritePreparedTxn::GetIterator(const ReadOptions& options,
+                                        ColumnFamilyHandle* column_family) {
+  // Make sure to get iterator from WritePrepareTxnDB, not the root db.
+  Iterator* db_iter = wpt_db_->NewIterator(options, column_family);
+  assert(db_iter);
+
+  return write_batch_.NewIteratorWithBase(column_family, db_iter);
+}
+
+Status WritePreparedTxn::PrepareInternal() {
+  WriteOptions write_options = write_options_;
+  write_options.disableWAL = false;
+  const bool WRITE_AFTER_COMMIT = true;
+  const bool kFirstPrepareBatch = true;
+  auto s = WriteBatchInternal::MarkEndPrepare(GetWriteBatch()->GetWriteBatch(),
+                                              name_, !WRITE_AFTER_COMMIT);
+  assert(s.ok());
+  // For each duplicate key we account for a new sub-batch
+  prepare_batch_cnt_ = GetWriteBatch()->SubBatchCnt();
+  // Having AddPrepared in the PreReleaseCallback allows in-order addition of
+  // prepared entries to PreparedHeap and hence enables an optimization. Refer
+  // to SmallestUnCommittedSeq for more details.
+  AddPreparedCallback add_prepared_callback(
+      wpt_db_, db_impl_, prepare_batch_cnt_,
+      db_impl_->immutable_db_options().two_write_queues, kFirstPrepareBatch);
+  const bool DISABLE_MEMTABLE = true;
+  uint64_t seq_used = kMaxSequenceNumber;
+  s = db_impl_->WriteImpl(write_options, GetWriteBatch()->GetWriteBatch(),
+                          /*callback*/ nullptr, &log_number_, /*log ref*/ 0,
+                          !DISABLE_MEMTABLE, &seq_used, prepare_batch_cnt_,
+                          &add_prepared_callback);
+  assert(!s.ok() || seq_used != kMaxSequenceNumber);
+  auto prepare_seq = seq_used;
+  SetId(prepare_seq);
+  return s;
+}
+
+Status WritePreparedTxn::CommitWithoutPrepareInternal() {
+  // For each duplicate key we account for a new sub-batch
+  const size_t batch_cnt = GetWriteBatch()->SubBatchCnt();
+  return CommitBatchInternal(GetWriteBatch()->GetWriteBatch(), batch_cnt);
+}
+
+Status WritePreparedTxn::CommitBatchInternal(WriteBatch* batch,
+                                             size_t batch_cnt) {
+  return wpt_db_->WriteInternal(write_options_, batch, batch_cnt, this);
+}
+
+Status WritePreparedTxn::CommitInternal() {
+  ROCKS_LOG_DETAILS(db_impl_->immutable_db_options().info_log,
+                    "CommitInternal prepare_seq: %" PRIu64, GetID());
+  // We take the commit-time batch and append the Commit marker.
+  // The Memtable will ignore the Commit marker in non-recovery mode
+  WriteBatch* working_batch = GetCommitTimeWriteBatch();
+  const bool empty = working_batch->Count() == 0;
+  auto s = WriteBatchInternal::MarkCommit(working_batch, name_);
+  assert(s.ok());
+
+  const bool for_recovery = use_only_the_last_commit_time_batch_for_recovery_;
+  if (!empty) {
+    // When not writing to memtable, we can still cache the latest write batch.
+    // The cached batch will be written to memtable in WriteRecoverableState
+    // during FlushMemTable
+    if (for_recovery) {
+      WriteBatchInternal::SetAsLatestPersistentState(working_batch);
+    } else {
+      return Status::InvalidArgument(
+          "Commit-time-batch can only be used if "
+          "use_only_the_last_commit_time_batch_for_recovery is true");
+    }
+  }
+
+  auto prepare_seq = GetId();
+  const bool includes_data = !empty && !for_recovery;
+  assert(prepare_batch_cnt_);
+  size_t commit_batch_cnt = 0;
+  if (UNLIKELY(includes_data)) {
+    ROCKS_LOG_WARN(db_impl_->immutable_db_options().info_log,
+                   "Duplicate key overhead");
+    SubBatchCounter counter(*wpt_db_->GetCFComparatorMap());
+    s = working_batch->Iterate(&counter);
+    assert(s.ok());
+    commit_batch_cnt = counter.BatchCount();
+  }
+  const bool disable_memtable = !includes_data;
+  const bool do_one_write =
+      !db_impl_->immutable_db_options().two_write_queues || disable_memtable;
+  WritePreparedCommitEntryPreReleaseCallback update_commit_map(
+      wpt_db_, db_impl_, prepare_seq, prepare_batch_cnt_, commit_batch_cnt);
+  // This is to call AddPrepared on CommitTimeWriteBatch
+  const bool kFirstPrepareBatch = true;
+  AddPreparedCallback add_prepared_callback(
+      wpt_db_, db_impl_, commit_batch_cnt,
+      db_impl_->immutable_db_options().two_write_queues, !kFirstPrepareBatch);
+  PreReleaseCallback* pre_release_callback;
+  if (do_one_write) {
+    pre_release_callback = &update_commit_map;
+  } else {
+    pre_release_callback = &add_prepared_callback;
+  }
+  uint64_t seq_used = kMaxSequenceNumber;
+  // Since the prepared batch is directly written to memtable, there is already
+  // a connection between the memtable and its WAL, so there is no need to
+  // redundantly reference the log that contains the prepared data.
+  const uint64_t zero_log_number = 0ull;
+  size_t batch_cnt = UNLIKELY(commit_batch_cnt) ? commit_batch_cnt : 1;
+  // If `two_write_queues && includes_data`, then `do_one_write` is false. The
+  // following `WriteImpl` will insert the data of the commit-time-batch into
+  // the database before updating the commit cache. Therefore, the data of the
+  // commmit-time-batch is considered uncommitted. Furthermore, since data of
+  // the commit-time-batch are not locked, it is possible for two uncommitted
+  // versions of the same key to co-exist for a (short) period of time until
+  // the commit cache is updated by the second write. If the two uncommitted
+  // keys are compacted to the bottommost level in the meantime, it is possible
+  // that compaction iterator will zero out the sequence numbers of both, thus
+  // violating the invariant that an SST does not have two identical internal
+  // keys. To prevent this situation, we should allow the usage of
+  // commit-time-batch only if the user sets
+  // TransactionOptions::use_only_the_last_commit_time_batch_for_recovery to
+  // true. See the comments about GetCommitTimeWriteBatch() in
+  // include/rocksdb/utilities/transaction.h.
+  s = db_impl_->WriteImpl(write_options_, working_batch, nullptr, nullptr,
+                          zero_log_number, disable_memtable, &seq_used,
+                          batch_cnt, pre_release_callback);
+  assert(!s.ok() || seq_used != kMaxSequenceNumber);
+  const SequenceNumber commit_batch_seq = seq_used;
+  if (LIKELY(do_one_write || !s.ok())) {
+    if (UNLIKELY(!db_impl_->immutable_db_options().two_write_queues &&
+                 s.ok())) {
+      // Note: RemovePrepared should be called after WriteImpl that publishsed
+      // the seq. Otherwise SmallestUnCommittedSeq optimization breaks.
+      wpt_db_->RemovePrepared(prepare_seq, prepare_batch_cnt_);
+    }  // else RemovePrepared is called from within PreReleaseCallback
+    if (UNLIKELY(!do_one_write)) {
+      assert(!s.ok());
+      // Cleanup the prepared entry we added with add_prepared_callback
+      wpt_db_->RemovePrepared(commit_batch_seq, commit_batch_cnt);
+    }
+    return s;
+  }  // else do the 2nd write to publish seq
+  // Note: the 2nd write comes with a performance penality. So if we have too
+  // many of commits accompanied with ComitTimeWriteBatch and yet we cannot
+  // enable use_only_the_last_commit_time_batch_for_recovery_ optimization,
+  // two_write_queues should be disabled to avoid many additional writes here.
+  const size_t kZeroData = 0;
+  // Update commit map only from the 2nd queue
+  WritePreparedCommitEntryPreReleaseCallback update_commit_map_with_aux_batch(
+      wpt_db_, db_impl_, prepare_seq, prepare_batch_cnt_, kZeroData,
+      commit_batch_seq, commit_batch_cnt);
+  WriteBatch empty_batch;
+  s = empty_batch.PutLogData(Slice());
+  assert(s.ok());
+  // In the absence of Prepare markers, use Noop as a batch separator
+  s = WriteBatchInternal::InsertNoop(&empty_batch);
+  assert(s.ok());
+  const bool DISABLE_MEMTABLE = true;
+  const size_t ONE_BATCH = 1;
+  const uint64_t NO_REF_LOG = 0;
+  s = db_impl_->WriteImpl(write_options_, &empty_batch, nullptr, nullptr,
+                          NO_REF_LOG, DISABLE_MEMTABLE, &seq_used, ONE_BATCH,
+                          &update_commit_map_with_aux_batch);
+  assert(!s.ok() || seq_used != kMaxSequenceNumber);
+  return s;
+}
+
+Status WritePreparedTxn::RollbackInternal() {
+  ROCKS_LOG_WARN(db_impl_->immutable_db_options().info_log,
+                 "RollbackInternal prepare_seq: %" PRIu64, GetId());
+
+  assert(db_impl_);
+  assert(wpt_db_);
+
+  WriteBatch rollback_batch(0 /* reserved_bytes */, 0 /* max_bytes */,
+                            write_options_.protection_bytes_per_key,
+                            0 /* default_cf_ts_sz */);
+  assert(GetId() != kMaxSequenceNumber);
+  assert(GetId() > 0);
+  auto cf_map_shared_ptr = wpt_db_->GetCFHandleMap();
+  auto cf_comp_map_shared_ptr = wpt_db_->GetCFComparatorMap();
+  auto read_at_seq = kMaxSequenceNumber;
+  ReadOptions roptions;
+  // to prevent callback's seq to be overrriden inside DBImpk::Get
+  roptions.snapshot = wpt_db_->GetMaxSnapshot();
+  struct RollbackWriteBatchBuilder : public WriteBatch::Handler {
+    DBImpl* const db_;
+    WritePreparedTxnDB* const wpt_db_;
+    WritePreparedTxnReadCallback callback_;
+    WriteBatch* rollback_batch_;
+    std::map<uint32_t, const Comparator*>& comparators_;
+    std::map<uint32_t, ColumnFamilyHandle*>& handles_;
+    using CFKeys = std::set<Slice, SetComparator>;
+    std::map<uint32_t, CFKeys> keys_;
+    bool rollback_merge_operands_;
+    ReadOptions roptions_;
+
+    RollbackWriteBatchBuilder(
+        DBImpl* db, WritePreparedTxnDB* wpt_db, SequenceNumber snap_seq,
+        WriteBatch* dst_batch,
+        std::map<uint32_t, const Comparator*>& comparators,
+        std::map<uint32_t, ColumnFamilyHandle*>& handles,
+        bool rollback_merge_operands, const ReadOptions& _roptions)
+        : db_(db),
+          wpt_db_(wpt_db),
+          callback_(wpt_db, snap_seq),  // disable min_uncommitted optimization
+          rollback_batch_(dst_batch),
+          comparators_(comparators),
+          handles_(handles),
+          rollback_merge_operands_(rollback_merge_operands),
+          roptions_(_roptions) {}
+
+    Status Rollback(uint32_t cf, const Slice& key) {
+      Status s;
+      CFKeys& cf_keys = keys_[cf];
+      if (cf_keys.size() == 0) {  // just inserted
+        auto cmp = comparators_[cf];
+        keys_[cf] = CFKeys(SetComparator(cmp));
+      }
+      auto it = cf_keys.insert(key);
+      // second is false if a element already existed.
+      if (it.second == false) {
+        return s;
+      }
+
+      PinnableSlice pinnable_val;
+      bool not_used;
+      auto cf_handle = handles_[cf];
+      DBImpl::GetImplOptions get_impl_options;
+      get_impl_options.column_family = cf_handle;
+      get_impl_options.value = &pinnable_val;
+      get_impl_options.value_found = &not_used;
+      get_impl_options.callback = &callback_;
+      s = db_->GetImpl(roptions_, key, get_impl_options);
+      assert(s.ok() || s.IsNotFound());
+      if (s.ok()) {
+        s = rollback_batch_->Put(cf_handle, key, pinnable_val);
+        assert(s.ok());
+      } else if (s.IsNotFound()) {
+        // There has been no readable value before txn. By adding a delete we
+        // make sure that there will be none afterwards either.
+        if (wpt_db_->ShouldRollbackWithSingleDelete(cf_handle, key)) {
+          s = rollback_batch_->SingleDelete(cf_handle, key);
+        } else {
+          s = rollback_batch_->Delete(cf_handle, key);
+        }
+        assert(s.ok());
+      } else {
+        // Unexpected status. Return it to the user.
+      }
+      return s;
+    }
+
+    Status PutCF(uint32_t cf, const Slice& key, const Slice& /*val*/) override {
+      return Rollback(cf, key);
+    }
+
+    Status DeleteCF(uint32_t cf, const Slice& key) override {
+      return Rollback(cf, key);
+    }
+
+    Status SingleDeleteCF(uint32_t cf, const Slice& key) override {
+      return Rollback(cf, key);
+    }
+
+    Status MergeCF(uint32_t cf, const Slice& key,
+                   const Slice& /*val*/) override {
+      if (rollback_merge_operands_) {
+        return Rollback(cf, key);
+      } else {
+        return Status::OK();
+      }
+    }
+
+    Status MarkNoop(bool) override { return Status::OK(); }
+    Status MarkBeginPrepare(bool) override { return Status::OK(); }
+    Status MarkEndPrepare(const Slice&) override { return Status::OK(); }
+    Status MarkCommit(const Slice&) override { return Status::OK(); }
+    Status MarkRollback(const Slice&) override {
+      return Status::InvalidArgument();
+    }
+
+   protected:
+    Handler::OptionState WriteAfterCommit() const override {
+      return Handler::OptionState::kDisabled;
+    }
+  } rollback_handler(db_impl_, wpt_db_, read_at_seq, &rollback_batch,
+                     *cf_comp_map_shared_ptr.get(), *cf_map_shared_ptr.get(),
+                     wpt_db_->txn_db_options_.rollback_merge_operands,
+                     roptions);
+  auto s = GetWriteBatch()->GetWriteBatch()->Iterate(&rollback_handler);
+  if (!s.ok()) {
+    return s;
+  }
+  // The Rollback marker will be used as a batch separator
+  s = WriteBatchInternal::MarkRollback(&rollback_batch, name_);
+  assert(s.ok());
+  bool do_one_write = !db_impl_->immutable_db_options().two_write_queues;
+  const bool DISABLE_MEMTABLE = true;
+  const uint64_t NO_REF_LOG = 0;
+  uint64_t seq_used = kMaxSequenceNumber;
+  const size_t ONE_BATCH = 1;
+  const bool kFirstPrepareBatch = true;
+  // We commit the rolled back prepared batches. Although this is
+  // counter-intuitive, i) it is safe to do so, since the prepared batches are
+  // already canceled out by the rollback batch, ii) adding the commit entry to
+  // CommitCache will allow us to benefit from the existing mechanism in
+  // CommitCache that keeps an entry evicted due to max advance and yet overlaps
+  // with a live snapshot around so that the live snapshot properly skips the
+  // entry even if its prepare seq is lower than max_evicted_seq_.
+  AddPreparedCallback add_prepared_callback(
+      wpt_db_, db_impl_, ONE_BATCH,
+      db_impl_->immutable_db_options().two_write_queues, !kFirstPrepareBatch);
+  WritePreparedCommitEntryPreReleaseCallback update_commit_map(
+      wpt_db_, db_impl_, GetId(), prepare_batch_cnt_, ONE_BATCH);
+  PreReleaseCallback* pre_release_callback;
+  if (do_one_write) {
+    pre_release_callback = &update_commit_map;
+  } else {
+    pre_release_callback = &add_prepared_callback;
+  }
+  // Note: the rollback batch does not need AddPrepared since it is written to
+  // DB in one shot. min_uncommitted still works since it requires capturing
+  // data that is written to DB but not yet committed, while
+  // the rollback batch commits with PreReleaseCallback.
+  s = db_impl_->WriteImpl(write_options_, &rollback_batch, nullptr, nullptr,
+                          NO_REF_LOG, !DISABLE_MEMTABLE, &seq_used, ONE_BATCH,
+                          pre_release_callback);
+  assert(!s.ok() || seq_used != kMaxSequenceNumber);
+  if (!s.ok()) {
+    return s;
+  }
+  if (do_one_write) {
+    assert(!db_impl_->immutable_db_options().two_write_queues);
+    wpt_db_->RemovePrepared(GetId(), prepare_batch_cnt_);
+    return s;
+  }  // else do the 2nd write for commit
+  uint64_t rollback_seq = seq_used;
+  ROCKS_LOG_DETAILS(db_impl_->immutable_db_options().info_log,
+                    "RollbackInternal 2nd write rollback_seq: %" PRIu64,
+                    rollback_seq);
+  // Commit the batch by writing an empty batch to the queue that will release
+  // the commit sequence number to readers.
+  WritePreparedRollbackPreReleaseCallback update_commit_map_with_prepare(
+      wpt_db_, db_impl_, GetId(), rollback_seq, prepare_batch_cnt_);
+  WriteBatch empty_batch;
+  s = empty_batch.PutLogData(Slice());
+  assert(s.ok());
+  // In the absence of Prepare markers, use Noop as a batch separator
+  s = WriteBatchInternal::InsertNoop(&empty_batch);
+  assert(s.ok());
+  s = db_impl_->WriteImpl(write_options_, &empty_batch, nullptr, nullptr,
+                          NO_REF_LOG, DISABLE_MEMTABLE, &seq_used, ONE_BATCH,
+                          &update_commit_map_with_prepare);
+  assert(!s.ok() || seq_used != kMaxSequenceNumber);
+  ROCKS_LOG_DETAILS(db_impl_->immutable_db_options().info_log,
+                    "RollbackInternal (status=%s) commit: %" PRIu64,
+                    s.ToString().c_str(), GetId());
+  // TODO(lth): For WriteUnPrepared that rollback is called frequently,
+  // RemovePrepared could be moved to the callback to reduce lock contention.
+  if (s.ok()) {
+    wpt_db_->RemovePrepared(GetId(), prepare_batch_cnt_);
+  }
+  // Note: RemovePrepared for prepared batch is called from within
+  // PreReleaseCallback
+  wpt_db_->RemovePrepared(rollback_seq, ONE_BATCH);
+
+  return s;
+}
+
+Status WritePreparedTxn::ValidateSnapshot(ColumnFamilyHandle* column_family,
+                                          const Slice& key,
+                                          SequenceNumber* tracked_at_seq) {
+  assert(snapshot_);
+
+  SequenceNumber min_uncommitted =
+      static_cast_with_check<const SnapshotImpl>(snapshot_.get())
+          ->min_uncommitted_;
+  SequenceNumber snap_seq = snapshot_->GetSequenceNumber();
+  // tracked_at_seq is either max or the last snapshot with which this key was
+  // trackeed so there is no need to apply the IsInSnapshot to this comparison
+  // here as tracked_at_seq is not a prepare seq.
+  if (*tracked_at_seq <= snap_seq) {
+    // If the key has been previous validated at a sequence number earlier
+    // than the curent snapshot's sequence number, we already know it has not
+    // been modified.
+    return Status::OK();
+  }
+
+  *tracked_at_seq = snap_seq;
+
+  ColumnFamilyHandle* cfh =
+      column_family ? column_family : db_impl_->DefaultColumnFamily();
+
+  WritePreparedTxnReadCallback snap_checker(wpt_db_, snap_seq, min_uncommitted,
+                                            kBackedByDBSnapshot);
+  // TODO(yanqin): support user-defined timestamp
+  return TransactionUtil::CheckKeyForConflicts(
+      db_impl_, cfh, key.ToString(), snap_seq, /*ts=*/nullptr,
+      false /* cache_only */, &snap_checker, min_uncommitted);
+}
+
+void WritePreparedTxn::SetSnapshot() {
+  const bool kForWWConflictCheck = true;
+  SnapshotImpl* snapshot = wpt_db_->GetSnapshotInternal(kForWWConflictCheck);
+  SetSnapshotInternal(snapshot);
+}
+
+Status WritePreparedTxn::RebuildFromWriteBatch(WriteBatch* src_batch) {
+  auto ret = PessimisticTransaction::RebuildFromWriteBatch(src_batch);
+  prepare_batch_cnt_ = GetWriteBatch()->SubBatchCnt();
+  return ret;
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+
+#endif  // ROCKSDB_LITE