summaryrefslogtreecommitdiff
path: root/includes/registration/ExtensionRegistry.php
blob: 16d833568c3469f7cd3cbe2565fb44f3c3a22906 (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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
<?php

/**
 * ExtensionRegistry class
 *
 * The Registry loads JSON files, and uses a Processor
 * to extract information from them. It also registers
 * classes with the autoloader.
 *
 * @since 1.25
 */
class ExtensionRegistry {

	/**
	 * Version of the highest supported manifest version
	 */
	const MANIFEST_VERSION = 1;

	/**
	 * Version of the oldest supported manifest version
	 */
	const OLDEST_MANIFEST_VERSION = 1;

	/**
	 * Bump whenever the registration cache needs resetting
	 */
	const CACHE_VERSION = 1;

	/**
	 * Special key that defines the merge strategy
	 *
	 * @since 1.26
	 */
	const MERGE_STRATEGY = '_merge_strategy';

	/**
	 * @var BagOStuff
	 */
	protected $cache;

	/**
	 * Array of loaded things, keyed by name, values are credits information
	 *
	 * @var array
	 */
	private $loaded = array();

	/**
	 * List of paths that should be loaded
	 *
	 * @var array
	 */
	protected $queued = array();

	/**
	 * Items in the JSON file that aren't being
	 * set as globals
	 *
	 * @var array
	 */
	protected $attributes = array();

	/**
	 * @var ExtensionRegistry
	 */
	private static $instance;

	/**
	 * @return ExtensionRegistry
	 */
	public static function getInstance() {
		if ( self::$instance === null ) {
			self::$instance = new self();
		}

		return self::$instance;
	}

	public function __construct() {
		// We use a try/catch instead of the $fallback parameter because
		// we don't want to fail here if $wgObjectCaches is not configured
		// properly for APC setup
		try {
			$this->cache = ObjectCache::newAccelerator( array() );
		} catch ( MWException $e ) {
			$this->cache = new EmptyBagOStuff();
		}
	}

	/**
	 * @param string $path Absolute path to the JSON file
	 */
	public function queue( $path ) {
		global $wgExtensionInfoMTime;

		$mtime = $wgExtensionInfoMTime;
		if ( $mtime === false ) {
			if ( file_exists( $path ) ) {
				$mtime = filemtime( $path );
			} else {
				throw new Exception( "$path does not exist!" );
			}
			if ( !$mtime ) {
				$err = error_get_last();
				throw new Exception( "Couldn't stat $path: {$err['message']}" );
			}
		}
		$this->queued[$path] = $mtime;
	}

	public function loadFromQueue() {
		if ( !$this->queued ) {
			return;
		}

		// See if this queue is in APC
		$key = wfMemcKey( 'registration', md5( json_encode( $this->queued ) ), self::CACHE_VERSION );
		$data = $this->cache->get( $key );
		if ( $data ) {
			$this->exportExtractedData( $data );
		} else {
			$data = $this->readFromQueue( $this->queued );
			$this->exportExtractedData( $data );
			// Do this late since we don't want to extract it since we already
			// did that, but it should be cached
			$data['globals']['wgAutoloadClasses'] += $data['autoload'];
			unset( $data['autoload'] );
			$this->cache->set( $key, $data, 60 * 60 * 24 );
		}
		$this->queued = array();
	}

	/**
	 * Get the current load queue. Not intended to be used
	 * outside of the installer.
	 *
	 * @return array
	 */
	public function getQueue() {
		return $this->queued;
	}

	/**
	 * Clear the current load queue. Not intended to be used
	 * outside of the installer.
	 */
	public function clearQueue() {
		$this->queued = array();
	}

	/**
	 * Process a queue of extensions and return their extracted data
	 *
	 * @param array $queue keys are filenames, values are ignored
	 * @return array extracted info
	 * @throws Exception
	 */
	public function readFromQueue( array $queue ) {
		$data = array( 'globals' => array( 'wgAutoloadClasses' => array() ) );
		$autoloadClasses = array();
		$processor = new ExtensionProcessor();
		foreach ( $queue as $path => $mtime ) {
			$json = file_get_contents( $path );
			$info = json_decode( $json, /* $assoc = */ true );
			if ( !is_array( $info ) ) {
				throw new Exception( "$path is not a valid JSON file." );
			}
			$autoload = $this->processAutoLoader( dirname( $path ), $info );
			// Set up the autoloader now so custom processors will work
			$GLOBALS['wgAutoloadClasses'] += $autoload;
			$autoloadClasses += $autoload;
			$processor->extractInfo( $path, $info );
		}
		$data = $processor->getExtractedInfo();
		// Need to set this so we can += to it later
		$data['globals']['wgAutoloadClasses'] = array();
		foreach ( $data['credits'] as $credit ) {
			$data['globals']['wgExtensionCredits'][$credit['type']][] = $credit;
		}
		$data['globals']['wgExtensionCredits'][self::MERGE_STRATEGY] = 'array_merge_recursive';
		$data['autoload'] = $autoloadClasses;
		return $data;
	}

	protected function exportExtractedData( array $info ) {
		foreach ( $info['globals'] as $key => $val ) {
			// If a merge strategy is set, read it and remove it from the value
			// so it doesn't accidentally end up getting set.
			// Need to check $val is an array for PHP 5.3 which will return
			// true on isset( 'string'['foo'] ).
			if ( isset( $val[self::MERGE_STRATEGY] ) && is_array( $val ) ) {
				$mergeStrategy = $val[self::MERGE_STRATEGY];
				unset( $val[self::MERGE_STRATEGY] );
			} else {
				$mergeStrategy = 'array_merge';
			}

			// Optimistic: If the global is not set, or is an empty array, replace it entirely.
			// Will be O(1) performance.
			if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
				$GLOBALS[$key] = $val;
				continue;
			}

			if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
				// config setting that has already been overridden, don't set it
				continue;
			}

			switch ( $mergeStrategy ) {
				case 'array_merge_recursive':
					$GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
					break;
				case 'array_plus_2d':
					// First merge items that are in both arrays
					foreach ( $GLOBALS[$key] as $name => &$groupVal ) {
						if ( isset( $val[$name] ) ) {
							$groupVal += $val[$name];
						}
					}
					// Now add items that didn't exist yet
					$GLOBALS[$key] += $val;
					break;
				case 'array_plus':
					$GLOBALS[$key] += $val;
					break;
				case 'array_merge':
					$GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
					break;
				default:
					throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
			}
		}

		foreach ( $info['defines'] as $name => $val ) {
			define( $name, $val );
		}
		foreach ( $info['callbacks'] as $cb ) {
			call_user_func( $cb );
		}

		$this->loaded += $info['credits'];

		if ( $info['attributes'] ) {
			if ( !$this->attributes ) {
				$this->attributes = $info['attributes'];
			} else {
				$this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
			}
		}
	}

	/**
	 * Loads and processes the given JSON file without delay
	 *
	 * If some extensions are already queued, this will load
	 * those as well.
	 *
	 * @param string $path Absolute path to the JSON file
	 */
	public function load( $path ) {
		$this->loadFromQueue(); // First clear the queue
		$this->queue( $path );
		$this->loadFromQueue();
	}

	/**
	 * Whether a thing has been loaded
	 * @param string $name
	 * @return bool
	 */
	public function isLoaded( $name ) {
		return isset( $this->loaded[$name] );
	}

	/**
	 * @param string $name
	 * @return array
	 */
	public function getAttribute( $name ) {
		if ( isset( $this->attributes[$name] ) ) {
			return $this->attributes[$name];
		} else {
			return array();
		}
	}

	/**
	 * Get information about all things
	 *
	 * @return array
	 */
	public function getAllThings() {
		return $this->loaded;
	}

	/**
	 * Mark a thing as loaded
	 *
	 * @param string $name
	 * @param array $credits
	 */
	protected function markLoaded( $name, array $credits ) {
		$this->loaded[$name] = $credits;
	}

	/**
	 * Register classes with the autoloader
	 *
	 * @param string $dir
	 * @param array $info
	 * @return array
	 */
	protected function processAutoLoader( $dir, array $info ) {
		if ( isset( $info['AutoloadClasses'] ) ) {
			// Make paths absolute, relative to the JSON file
			return array_map( function( $file ) use ( $dir ) {
				return "$dir/$file";
			}, $info['AutoloadClasses'] );
		} else {
			return array();
		}
	}
}