rocksdb/db/log_format.h

//  Copyright (c) 2011-present, 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.
//
// 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.
//
// Log format information shared by reader and writer.
// See ../doc/log_format.txt for more detail.

#pragma once
namespace rocksdb {
namespace log {

enum RecordType {
  // Zero is reserved for preallocated files
  kZeroType = 0,
  kFullType = 1,

  // For fragments
  kFirstType = 2,
  kMiddleType = 3,
  kLastType = 4,

  // For recycled log files
  kRecyclableFullType = 5,
  kRecyclableFirstType = 6,
  kRecyclableMiddleType = 7,
  kRecyclableLastType = 8,
};
static const int kMaxRecordType = kRecyclableLastType;

static const unsigned int kBlockSize = 32768;

// Header is checksum (4 bytes), type (1 byte), length (2 bytes).
static const int kHeaderSize = 4 + 1 + 2;

// Recyclable header is checksum (4 bytes), type (1 byte), log number
// (4 bytes), length (2 bytes).
static const int kRecyclableHeaderSize = 4 + 1 + 4 + 2;

}  // namespace log
}  // namespace rocksdb