summaryrefslogtreecommitdiff
path: root/includes/filebackend/FileBackendGroup.php
blob: be8a207633c27fa45f2aca6369832f9bd701dc55 (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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
<?php
/**
 * File backend registration handling.
 *
 * 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.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup FileBackend
 * @author Aaron Schulz
 */

/**
 * Class to handle file backend registration
 *
 * @ingroup FileBackend
 * @since 1.19
 */
class FileBackendGroup {
	/**
	 * @var FileBackendGroup
	 */
	protected static $instance = null;

	/** @var Array (name => ('class' => string, 'config' => array, 'instance' => object)) */
	protected $backends = array();

	protected function __construct() {}

	/**
	 * @return FileBackendGroup
	 */
	public static function singleton() {
		if ( self::$instance == null ) {
			self::$instance = new self();
			self::$instance->initFromGlobals();
		}
		return self::$instance;
	}

	/**
	 * Destroy the singleton instance
	 *
	 * @return void
	 */
	public static function destroySingleton() {
		self::$instance = null;
	}

	/**
	 * Register file backends from the global variables
	 *
	 * @return void
	 */
	protected function initFromGlobals() {
		global $wgLocalFileRepo, $wgForeignFileRepos, $wgFileBackends;

		// Register explicitly defined backends
		$this->register( $wgFileBackends );

		$autoBackends = array();
		// Automatically create b/c backends for file repos...
		$repos = array_merge( $wgForeignFileRepos, array( $wgLocalFileRepo ) );
		foreach ( $repos as $info ) {
			$backendName = $info['backend'];
			if ( is_object( $backendName ) || isset( $this->backends[$backendName] ) ) {
				continue; // already defined (or set to the object for some reason)
			}
			$repoName = $info['name'];
			// Local vars that used to be FSRepo members...
			$directory = $info['directory'];
			$deletedDir = isset( $info['deletedDir'] )
				? $info['deletedDir']
				: false; // deletion disabled
			$thumbDir = isset( $info['thumbDir'] )
				? $info['thumbDir']
				: "{$directory}/thumb";
			$transcodedDir = isset( $info['transcodedDir'] )
				? $info['transcodedDir']
				: "{$directory}/transcoded";
			$fileMode = isset( $info['fileMode'] )
				? $info['fileMode']
				: 0644;
			// Get the FS backend configuration
			$autoBackends[] = array(
				'name' => $backendName,
				'class' => 'FSFileBackend',
				'lockManager' => 'fsLockManager',
				'containerPaths' => array(
					"{$repoName}-public" => "{$directory}",
					"{$repoName}-thumb" => $thumbDir,
					"{$repoName}-transcoded" => $transcodedDir,
					"{$repoName}-deleted" => $deletedDir,
					"{$repoName}-temp" => "{$directory}/temp"
				),
				'fileMode' => $fileMode,
			);
		}

		// Register implicitly defined backends
		$this->register( $autoBackends );
	}

	/**
	 * Register an array of file backend configurations
	 *
	 * @param Array $configs
	 * @return void
	 * @throws MWException
	 */
	protected function register( array $configs ) {
		foreach ( $configs as $config ) {
			if ( !isset( $config['name'] ) ) {
				throw new MWException( "Cannot register a backend with no name." );
			}
			$name = $config['name'];
			if ( isset( $this->backends[$name] ) ) {
				throw new MWException( "Backend with name `{$name}` already registered." );
			} elseif ( !isset( $config['class'] ) ) {
				throw new MWException( "Cannot register backend `{$name}` with no class." );
			}
			$class = $config['class'];

			unset( $config['class'] ); // backend won't need this
			$this->backends[$name] = array(
				'class' => $class,
				'config' => $config,
				'instance' => null
			);
		}
	}

	/**
	 * Get the backend object with a given name
	 *
	 * @param string $name
	 * @return FileBackend
	 * @throws MWException
	 */
	public function get( $name ) {
		if ( !isset( $this->backends[$name] ) ) {
			throw new MWException( "No backend defined with the name `$name`." );
		}
		// Lazy-load the actual backend instance
		if ( !isset( $this->backends[$name]['instance'] ) ) {
			$class = $this->backends[$name]['class'];
			$config = $this->backends[$name]['config'];
			$this->backends[$name]['instance'] = new $class( $config );
		}
		return $this->backends[$name]['instance'];
	}

	/**
	 * Get the config array for a backend object with a given name
	 *
	 * @param string $name
	 * @return Array
	 * @throws MWException
	 */
	public function config( $name ) {
		if ( !isset( $this->backends[$name] ) ) {
			throw new MWException( "No backend defined with the name `$name`." );
		}
		$class = $this->backends[$name]['class'];
		return array( 'class' => $class ) + $this->backends[$name]['config'];
	}

	/**
	 * Get an appropriate backend object from a storage path
	 *
	 * @param string $storagePath
	 * @return FileBackend|null Backend or null on failure
	 */
	public function backendFromPath( $storagePath ) {
		list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
		if ( $backend !== null && isset( $this->backends[$backend] ) ) {
			return $this->get( $backend );
		}
		return null;
	}
}