You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
rocksdb/utilities/transactions/write_unprepared_txn.cc

90 lines
3.2 KiB

// 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_unprepared_txn.h"
#include "db/db_impl.h"
#include "util/cast_util.h"
#include "utilities/transactions/write_unprepared_txn_db.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
namespace rocksdb {
bool WriteUnpreparedTxnReadCallback::IsVisible(SequenceNumber seq) {
auto unprep_seqs = txn_->GetUnpreparedSequenceNumbers();
// Since unprep_seqs maps prep_seq => prepare_batch_cnt, to check if seq is
// in unprep_seqs, we have to check if seq is equal to prep_seq or any of
// the prepare_batch_cnt seq nums after it.
//
// TODO(lth): Can be optimized with std::lower_bound if unprep_seqs is
// large.
for (const auto& it : unprep_seqs) {
if (it.first <= seq && seq < it.first + it.second) {
return true;
}
}
return db_->IsInSnapshot(seq, snapshot_, min_uncommitted_);
}
SequenceNumber WriteUnpreparedTxnReadCallback::MaxUnpreparedSequenceNumber() {
auto unprep_seqs = txn_->GetUnpreparedSequenceNumbers();
if (unprep_seqs.size()) {
return unprep_seqs.rbegin()->first + unprep_seqs.rbegin()->second - 1;
}
return 0;
}
WriteUnpreparedTxn::WriteUnpreparedTxn(WriteUnpreparedTxnDB* txn_db,
const WriteOptions& write_options,
const TransactionOptions& txn_options)
: WritePreparedTxn(txn_db, write_options, txn_options), wupt_db_(txn_db) {}
Status WriteUnpreparedTxn::Get(const ReadOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key, PinnableSlice* value) {
auto snapshot = options.snapshot;
auto snap_seq =
snapshot != nullptr ? snapshot->GetSequenceNumber() : kMaxSequenceNumber;
SequenceNumber min_uncommitted = 0; // by default disable the optimization
if (snapshot != nullptr) {
min_uncommitted =
static_cast_with_check<const SnapshotImpl, const Snapshot>(snapshot)
->min_uncommitted_;
}
WriteUnpreparedTxnReadCallback callback(wupt_db_, snap_seq, min_uncommitted,
this);
return write_batch_.GetFromBatchAndDB(db_, options, column_family, key, value,
&callback);
}
Iterator* WriteUnpreparedTxn::GetIterator(const ReadOptions& options) {
return GetIterator(options, wupt_db_->DefaultColumnFamily());
}
Iterator* WriteUnpreparedTxn::GetIterator(const ReadOptions& options,
ColumnFamilyHandle* column_family) {
// Make sure to get iterator from WriteUnprepareTxnDB, not the root db.
Iterator* db_iter = wupt_db_->NewIterator(options, column_family, this);
assert(db_iter);
return write_batch_.NewIteratorWithBase(column_family, db_iter);
}
const std::map<SequenceNumber, size_t>&
WriteUnpreparedTxn::GetUnpreparedSequenceNumbers() {
return unprep_seqs_;
}
} // namespace rocksdb
#endif // ROCKSDB_LITE