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mongodb/db/dur_journalimpl.h
2010-12-21 01:59:33 -05:00

81 lines
2.5 KiB
C++

// @file dur_journal.h
/**
* Copyright (C) 2010 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "../util/concurrency/mvar.h"
namespace mongo {
namespace dur {
class Journal {
public:
string dir; // set by journalMakeDir() during initialization
MVar<path> &toUnlink; // unlinks of old journal threads are via background thread
MVar<unsigned long long> &toStoreLastSeqNum;
Journal();
void init();
void rotate();
void journal(const AlignedBuilder& b);
boost::filesystem::path getFilePathFor(int filenumber) const;
/** used at shutdown.
@return false if can't close in a timely manner.
*/
bool tryToCloseCurJournalFile();
private:
static const unsigned long long DataLimit = 1 * 1024 * 1024 * 1024;
/** open a journal file to journal operations to. */
void open();
void _open();
void closeCurrentJournalFile();
void removeUnneededJournalFiles();
unsigned long long _written; // bytes written so far to the current journal (log) file
unsigned _nextFileNumber;
mutex _curLogFileMutex;
LogFile *_curLogFile; // use _curLogFileMutex
struct JFile {
string filename;
unsigned long long lastEventTimeMs;
};
// files which have been closed but not unlinked (rotated out) yet
// ordered oldest to newest
list<JFile> _oldJournalFiles; // use _curLogFileMutex
static void preFlush();
static void postFlush();
unsigned long long _preFlushTime;
unsigned long long _lastFlushTime; // data < this time is fsynced in the datafiles (unless hard drive controller is caching)
};
}
}