mirror of
https://github.com/facebook/rocksdb.git
synced 2024-11-26 16:30:56 +00:00
62 lines
2.3 KiB
C
62 lines
2.3 KiB
C
|
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
|
||
|
|
// This source code is licensed under both the GPLv2 (found in the
|
||
|
|
// COPYING file in the root directory) and Apache 2.0 License
|
||
|
|
// (found in the LICENSE.Apache file in the root directory).
|
||
|
|
//
|
||
|
|
#pragma once
|
||
|
|
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <cassert>
|
||
|
|
#include <cstdlib>
|
||
|
|
#include <mutex>
|
||
|
|
#include <unordered_map>
|
||
|
|
#include <vector>
|
||
|
|
|
||
|
|
namespace rocksdb {
|
||
|
|
|
||
|
|
// This class is used to track the log files with outstanding prepare entries.
|
||
|
|
class LogsWithPrepTracker {
|
||
|
|
public:
|
||
|
|
// Called when a transaction prepared in `log` has been committed or aborted.
|
||
|
|
void MarkLogAsHavingPrepSectionFlushed(uint64_t log);
|
||
|
|
// Called when a transaction is prepared in `log`.
|
||
|
|
void MarkLogAsContainingPrepSection(uint64_t log);
|
||
|
|
// Return the earliest log file with outstanding prepare entries.
|
||
|
|
uint64_t FindMinLogContainingOutstandingPrep();
|
||
|
|
size_t TEST_PreparedSectionCompletedSize() {
|
||
|
|
return prepared_section_completed_.size();
|
||
|
|
}
|
||
|
|
size_t TEST_LogsWithPrepSize() { return logs_with_prep_.size(); }
|
||
|
|
|
||
|
|
private:
|
||
|
|
// REQUIRES: logs_with_prep_mutex_ held
|
||
|
|
//
|
||
|
|
// sorted list of log numbers still containing prepared data.
|
||
|
|
// this is used by FindObsoleteFiles to determine which
|
||
|
|
// flushed logs we must keep around because they still
|
||
|
|
// contain prepared data which has not been committed or rolled back
|
||
|
|
struct LogCnt {
|
||
|
|
uint64_t log; // the log number
|
||
|
|
uint64_t cnt; // number of prepared sections in the log
|
||
|
|
};
|
||
|
|
std::vector<LogCnt> logs_with_prep_;
|
||
|
|
std::mutex logs_with_prep_mutex_;
|
||
|
|
|
||
|
|
// REQUIRES: prepared_section_completed_mutex_ held
|
||
|
|
//
|
||
|
|
// to be used in conjunction with logs_with_prep_.
|
||
|
|
// once a transaction with data in log L is committed or rolled back
|
||
|
|
// rather than updating logs_with_prep_ directly we keep track of that
|
||
|
|
// in prepared_section_completed_ which maps LOG -> instance_count. This helps
|
||
|
|
// avoiding contention between a commit thread and the prepare threads.
|
||
|
|
//
|
||
|
|
// when trying to determine the minimum log still active we first
|
||
|
|
// consult logs_with_prep_. while that root value maps to
|
||
|
|
// an equal value in prepared_section_completed_ we erase the log from
|
||
|
|
// both logs_with_prep_ and prepared_section_completed_.
|
||
|
|
std::unordered_map<uint64_t, uint64_t> prepared_section_completed_;
|
||
|
|
std::mutex prepared_section_completed_mutex_;
|
||
|
|
|
||
|
|
};
|
||
|
|
} // namespace rocksdb
|