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rocksdb/db/transaction_log_impl.h

121 lines
3.9 KiB

// 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.
#ifndef ROCKSDB_LITE
#pragma once
#include <vector>
#include "rocksdb/env.h"
#include "rocksdb/options.h"
#include "rocksdb/types.h"
#include "rocksdb/transaction_log.h"
#include "db/db_impl.h"
#include "db/log_reader.h"
#include "db/filename.h"
namespace rocksdb {
struct LogReporter : public log::Reader::Reporter {
Env* env;
Logger* info_log;
virtual void Corruption(size_t bytes, const Status& s) {
Log(info_log, "dropping %zu bytes; %s", bytes, s.ToString().c_str());
}
virtual void Info(const char* s) {
Log(info_log, "%s", s);
}
};
class LogFileImpl : public LogFile {
public:
LogFileImpl(uint64_t logNum, WalFileType logType, SequenceNumber startSeq,
uint64_t sizeBytes) :
logNumber_(logNum),
type_(logType),
startSequence_(startSeq),
sizeFileBytes_(sizeBytes) {
}
std::string PathName() const {
if (type_ == kArchivedLogFile) {
return ArchivedLogFileName("", logNumber_);
}
return LogFileName("", logNumber_);
}
uint64_t LogNumber() const { return logNumber_; }
WalFileType Type() const { return type_; }
SequenceNumber StartSequence() const { return startSequence_; }
uint64_t SizeFileBytes() const { return sizeFileBytes_; }
bool operator < (const LogFile& that) const {
return LogNumber() < that.LogNumber();
}
private:
uint64_t logNumber_;
WalFileType type_;
SequenceNumber startSequence_;
uint64_t sizeFileBytes_;
};
class TransactionLogIteratorImpl : public TransactionLogIterator {
public:
TransactionLogIteratorImpl(
const std::string& dir, const DBOptions* options,
const TransactionLogIterator::ReadOptions& read_options,
const EnvOptions& soptions, const SequenceNumber seqNum,
std::unique_ptr<VectorLogPtr> files, DBImpl const* const dbimpl);
virtual bool Valid();
virtual void Next();
virtual Status status();
virtual BatchResult GetBatch();
private:
const std::string& dir_;
const DBOptions* options_;
const TransactionLogIterator::ReadOptions read_options_;
const EnvOptions& soptions_;
SequenceNumber startingSequenceNumber_;
std::unique_ptr<VectorLogPtr> files_;
bool started_;
bool isValid_; // not valid when it starts of.
Status currentStatus_;
size_t currentFileIndex_;
std::unique_ptr<WriteBatch> currentBatch_;
unique_ptr<log::Reader> currentLogReader_;
Status OpenLogFile(const LogFile* logFile, unique_ptr<SequentialFile>* file);
LogReporter reporter_;
SequenceNumber currentBatchSeq_; // sequence number at start of current batch
SequenceNumber currentLastSeq_; // last sequence in the current batch
DBImpl const * const dbimpl_; // The db on whose log files this iterates
// Reads from transaction log only if the writebatch record has been written
bool RestrictedRead(Slice* record, std::string* scratch);
// Seeks to startingSequenceNumber reading from startFileIndex in files_.
// If strict is set,then must get a batch starting with startingSequenceNumber
void SeekToStartSequence(uint64_t startFileIndex = 0, bool strict = false);
// Implementation of Next. SeekToStartSequence calls it internally with
// internal=true to let it find next entry even if it has to jump gaps because
// the iterator may start off from the first available entry but promises to
// be continuous after that
void NextImpl(bool internal = false);
// Check if batch is expected, else return false
bool IsBatchExpected(const WriteBatch* batch, SequenceNumber expectedSeq);
// Update current batch if a continuous batch is found, else return false
void UpdateCurrentWriteBatch(const Slice& record);
Status OpenLogReader(const LogFile* file);
};
} // namespace rocksdb
#endif // ROCKSDB_LITE