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/*
* 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.
*/
/** \file
*
* This header declares the db_plugin class. It describes a
* plugin API for databases of song metadata.
*/
#ifndef MPD_DATABASE_PLUGIN_HXX
#define MPD_DATABASE_PLUGIN_HXX
#include "DatabaseVisitor.hxx"
#include "tag/TagType.h"
#include "Compiler.h"
#include <time.h>
struct config_param;
struct DatabaseSelection;
struct db_visitor;
struct Song;
class Error;
class EventLoop;
class DatabaseListener;
struct DatabaseStats {
/**
* Number of songs.
*/
unsigned song_count;
/**
* Total duration of all songs (in seconds).
*/
unsigned long total_duration;
/**
* Number of distinct artist names.
*/
unsigned artist_count;
/**
* Number of distinct album names.
*/
unsigned album_count;
void Clear() {
song_count = 0;
total_duration = 0;
artist_count = album_count = 0;
}
};
class Database {
public:
/**
* Free instance data.
*/
virtual ~Database() {}
/**
* Open the database. Read it into memory if applicable.
*/
virtual bool Open(gcc_unused Error &error) {
return true;
}
/**
* Close the database, free allocated memory.
*/
virtual void Close() {}
/**
* Look up a song (including tag data) in the database. When
* you don't need this anymore, call ReturnSong().
*
* @param uri_utf8 the URI of the song within the music
* directory (UTF-8)
*/
virtual Song *GetSong(const char *uri_utf8,
Error &error) const = 0;
/**
* Mark the song object as "unused". Call this on objects
* returned by GetSong().
*/
virtual void ReturnSong(Song *song) const = 0;
/**
* Visit the selected entities.
*/
virtual bool Visit(const DatabaseSelection &selection,
VisitDirectory visit_directory,
VisitSong visit_song,
VisitPlaylist visit_playlist,
Error &error) const = 0;
bool Visit(const DatabaseSelection &selection,
VisitDirectory visit_directory,
VisitSong visit_song,
Error &error) const {
return Visit(selection, visit_directory, visit_song,
VisitPlaylist(), error);
}
bool Visit(const DatabaseSelection &selection, VisitSong visit_song,
Error &error) const {
return Visit(selection, VisitDirectory(), visit_song, error);
}
/**
* Visit all unique tag values.
*/
virtual bool VisitUniqueTags(const DatabaseSelection &selection,
TagType tag_type,
VisitString visit_string,
Error &error) const = 0;
virtual bool GetStats(const DatabaseSelection &selection,
DatabaseStats &stats,
Error &error) const = 0;
/**
* Returns the time stamp of the last database update.
* Returns 0 if that is not not known/available.
*/
gcc_pure
virtual time_t GetUpdateStamp() const = 0;
};
struct DatabasePlugin {
const char *name;
/**
* Allocates and configures a database.
*/
Database *(*create)(EventLoop &loop, DatabaseListener &listener,
const config_param ¶m,
Error &error);
};
#endif
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