/usr/include/rocksdb/transaction_log.h is in librocksdb-dev 4.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 | // 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 STORAGE_ROCKSDB_INCLUDE_TRANSACTION_LOG_ITERATOR_H_
#define STORAGE_ROCKSDB_INCLUDE_TRANSACTION_LOG_ITERATOR_H_
#include "rocksdb/status.h"
#include "rocksdb/types.h"
#include "rocksdb/write_batch.h"
#include <memory>
#include <vector>
namespace rocksdb {
class LogFile;
typedef std::vector<std::unique_ptr<LogFile>> VectorLogPtr;
enum WalFileType {
/* Indicates that WAL file is in archive directory. WAL files are moved from
* the main db directory to archive directory once they are not live and stay
* there until cleaned up. Files are cleaned depending on archive size
* (Options::WAL_size_limit_MB) and time since last cleaning
* (Options::WAL_ttl_seconds).
*/
kArchivedLogFile = 0,
/* Indicates that WAL file is live and resides in the main db directory */
kAliveLogFile = 1
} ;
class LogFile {
public:
LogFile() {}
virtual ~LogFile() {}
// Returns log file's pathname relative to the main db dir
// Eg. For a live-log-file = /000003.log
// For an archived-log-file = /archive/000003.log
virtual std::string PathName() const = 0;
// Primary identifier for log file.
// This is directly proportional to creation time of the log file
virtual uint64_t LogNumber() const = 0;
// Log file can be either alive or archived
virtual WalFileType Type() const = 0;
// Starting sequence number of writebatch written in this log file
virtual SequenceNumber StartSequence() const = 0;
// Size of log file on disk in Bytes
virtual uint64_t SizeFileBytes() const = 0;
};
struct BatchResult {
SequenceNumber sequence = 0;
std::unique_ptr<WriteBatch> writeBatchPtr;
// Add empty __ctor and __dtor for the rule of five
// However, preserve the original semantics and prohibit copying
// as the unique_ptr member does not copy.
BatchResult() {}
~BatchResult() {}
BatchResult(const BatchResult&) = delete;
BatchResult& operator=(const BatchResult&) = delete;
BatchResult(BatchResult&& bResult)
: sequence(std::move(bResult.sequence)),
writeBatchPtr(std::move(bResult.writeBatchPtr)) {}
BatchResult& operator=(BatchResult&& bResult) {
sequence = std::move(bResult.sequence);
writeBatchPtr = std::move(bResult.writeBatchPtr);
return *this;
}
};
// A TransactionLogIterator is used to iterate over the transactions in a db.
// One run of the iterator is continuous, i.e. the iterator will stop at the
// beginning of any gap in sequences
class TransactionLogIterator {
public:
TransactionLogIterator() {}
virtual ~TransactionLogIterator() {}
// An iterator is either positioned at a WriteBatch or not valid.
// This method returns true if the iterator is valid.
// Can read data from a valid iterator.
virtual bool Valid() = 0;
// Moves the iterator to the next WriteBatch.
// REQUIRES: Valid() to be true.
virtual void Next() = 0;
// Returns ok if the iterator is valid.
// Returns the Error when something has gone wrong.
virtual Status status() = 0;
// If valid return's the current write_batch and the sequence number of the
// earliest transaction contained in the batch.
// ONLY use if Valid() is true and status() is OK.
virtual BatchResult GetBatch() = 0;
// The read options for TransactionLogIterator.
struct ReadOptions {
// If true, all data read from underlying storage will be
// verified against corresponding checksums.
// Default: true
bool verify_checksums_;
ReadOptions() : verify_checksums_(true) {}
explicit ReadOptions(bool verify_checksums)
: verify_checksums_(verify_checksums) {}
};
};
} // namespace rocksdb
#endif // STORAGE_ROCKSDB_INCLUDE_TRANSACTION_LOG_ITERATOR_H_
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