mpd/src/StateFile.hxx
2014-01-13 22:31:55 +01:00

73 lines
1.8 KiB
C++

/*
* Copyright (C) 2003-2014 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_STATE_FILE_HXX
#define MPD_STATE_FILE_HXX
#include "event/TimeoutMonitor.hxx"
#include "fs/AllocatedPath.hxx"
#include "Compiler.h"
#include <string>
struct Partition;
class StateFile final : private TimeoutMonitor {
AllocatedPath path;
std::string path_utf8;
Partition &partition;
/**
* These version numbers determine whether we need to save the state
* file. If nothing has changed, we won't let the hard drive spin up.
*/
unsigned prev_volume_version, prev_output_version,
prev_playlist_version;
public:
StateFile(AllocatedPath &&path, Partition &partition, EventLoop &loop);
void Read();
void Write();
/**
* Schedules a write if MPD's state was modified.
*/
void CheckModified();
private:
/**
* Save the current state versions for use with IsModified().
*/
void RememberVersions();
/**
* Check if MPD's state was modified since the last
* RememberVersions() call.
*/
gcc_pure
bool IsModified() const;
/* virtual methods from TimeoutMonitor */
virtual void OnTimeout() override;
};
#endif /* STATE_FILE_H */