rocksdb/db/log_writer.h

49 lines
1.3 KiB
C++

// 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.
#ifndef STORAGE_LEVELDB_DB_LOG_WRITER_H_
#define STORAGE_LEVELDB_DB_LOG_WRITER_H_
#include <stdint.h>
#include "db/log_format.h"
#include "leveldb/slice.h"
#include "leveldb/status.h"
namespace leveldb {
class WritableFile;
namespace log {
class Writer {
public:
// Create a writer that will append data to "*dest".
// "*dest" must be initially empty.
// "*dest" must remain live while this Writer is in use.
explicit Writer(WritableFile* dest);
~Writer();
Status AddRecord(const Slice& slice);
private:
WritableFile* dest_;
int block_offset_; // Current offset in block
// crc32c values for all supported record types. These are
// pre-computed to reduce the overhead of computing the crc of the
// record type stored in the header.
uint32_t type_crc_[kMaxRecordType + 1];
Status EmitPhysicalRecord(RecordType type, const char* ptr, size_t length);
// No copying allowed
Writer(const Writer&);
void operator=(const Writer&);
};
} // namespace log
} // namespace leveldb
#endif // STORAGE_LEVELDB_DB_LOG_WRITER_H_