summaryrefslogtreecommitdiff
path: root/src/DatabasePlugin.hxx
blob: 0477d5d8840af2606bf1e4e54d8f0e86a574b720 (plain)
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
30
31
32
33
34
35
36
37
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
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/*
 * 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"
#include "tag/TagType.h"
#include "Compiler.h"

struct config_param;
struct DatabaseSelection;
struct db_visitor;
struct Song;
class Error;

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,
				     enum tag_type tag_type,
				     VisitString visit_string,
				     Error &error) const = 0;

	virtual bool GetStats(const DatabaseSelection &selection,
			      DatabaseStats &stats,
			      Error &error) const = 0;
};

struct DatabasePlugin {
	const char *name;

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

#endif