a7b2bedfb0
Introduce new tags for records that have a log_number. This changes the header size from 7 to 11 for these records, making this a backward-incompatible change. If we read a record that belongs to a different log_number (i.e., a previous instantiation of this log file, before it was most recently recycled), we return kOldRecord from ReadPhysicalRecord. ReadRecord will translate this into a kEof or kBadRecord depending on what the WAL recovery mode is. We make several adjustments to the log_test.cc tests to compensate for the fact that the header size varies between the two modes. Signed-off-by: Sage Weil <sage@redhat.com>
46 lines
1.4 KiB
C++
46 lines
1.4 KiB
C++
// 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.
|
|
//
|
|
// 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
|