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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.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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//
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// Log format information shared by reader and writer.
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// See ../doc/log_format.txt for more detail.
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#pragma once
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namespace rocksdb {
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namespace log {
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enum RecordType {
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// Zero is reserved for preallocated files
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kZeroType = 0,
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kFullType = 1,
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// For fragments
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kFirstType = 2,
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kMiddleType = 3,
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kLastType = 4,
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// For recycled log files
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kRecyclableFullType = 5,
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kRecyclableFirstType = 6,
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kRecyclableMiddleType = 7,
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kRecyclableLastType = 8,
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};
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static const int kMaxRecordType = kRecyclableLastType;
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static const unsigned int kBlockSize = 32768;
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// Header is checksum (4 bytes), type (1 byte), length (2 bytes).
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static const int kHeaderSize = 4 + 1 + 2;
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// Recyclable header is checksum (4 bytes), type (1 byte), log number
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// (4 bytes), length (2 bytes).
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static const int kRecyclableHeaderSize = 4 + 1 + 4 + 2;
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} // namespace log
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} // namespace rocksdb
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