DatabasePlugin.hxx 3.41 KB
Newer Older
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
/*
 * Copyright (C) 2003-2011 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"
30
#include "tag/TagType.h"
31
#include "Compiler.h"
32 33

struct config_param;
34
struct DatabaseSelection;
35
struct db_visitor;
36
struct Song;
37
class Error;
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
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;
	}
};

67 68 69 70 71 72 73 74 75 76
class Database {
public:
	/**
	 * Free instance data.
         */
	virtual ~Database() {}

	/**
         * Open the database.  Read it into memory if applicable.
	 */
77
	virtual bool Open(gcc_unused Error &error) {
78 79 80 81 82 83 84 85 86
		return true;
	}

	/**
         * Close the database, free allocated memory.
	 */
	virtual void Close() {}

	/**
87 88
         * Look up a song (including tag data) in the database.  When
         * you don't need this anymore, call ReturnSong().
89 90 91 92
	 *
	 * @param uri_utf8 the URI of the song within the music
	 * directory (UTF-8)
	 */
93
	virtual Song *GetSong(const char *uri_utf8,
94
			      Error &error) const = 0;
95

96 97 98 99
	/**
	 * Mark the song object as "unused".  Call this on objects
	 * returned by GetSong().
	 */
100
	virtual void ReturnSong(Song *song) const = 0;
101

102 103 104
	/**
	 * Visit the selected entities.
	 */
105
	virtual bool Visit(const DatabaseSelection &selection,
106 107 108
			   VisitDirectory visit_directory,
			   VisitSong visit_song,
			   VisitPlaylist visit_playlist,
109
			   Error &error) const = 0;
110

111
	bool Visit(const DatabaseSelection &selection,
112 113
		   VisitDirectory visit_directory,
		   VisitSong visit_song,
114
		   Error &error) const {
115
		return Visit(selection, visit_directory, visit_song,
116
			     VisitPlaylist(), error);
117 118
	}

119
	bool Visit(const DatabaseSelection &selection, VisitSong visit_song,
120 121
		   Error &error) const {
		return Visit(selection, VisitDirectory(), visit_song, error);
122
	}
123 124 125 126 127 128 129

	/**
	 * Visit all unique tag values.
	 */
	virtual bool VisitUniqueTags(const DatabaseSelection &selection,
				     enum tag_type tag_type,
				     VisitString visit_string,
130
				     Error &error) const = 0;
131 132 133

	virtual bool GetStats(const DatabaseSelection &selection,
			      DatabaseStats &stats,
134
			      Error &error) const = 0;
135 136 137 138 139 140 141 142
};

struct DatabasePlugin {
	const char *name;

	/**
	 * Allocates and configures a database.
	 */
143
	Database *(*create)(const config_param &param,
144
			    Error &error);
145 146 147
};

#endif