includes/registration/ExtensionRegistry.php

   1 <?php
   2
   3 /**
   4  * ExtensionRegistry class
   5  *
   6  * The Registry loads JSON files, and uses a Processor
   7  * to extract information from them. It also registers
   8  * classes with the autoloader.
   9  *
  10  * @since 1.25
  11  */
  12 class ExtensionRegistry {
  13
  14         /**
  15          * Version of the highest supported manifest version
  16          */
  17         const MANIFEST_VERSION = 1;
  18
  19         /**
  20          * Version of the oldest supported manifest version
  21          */
  22         const OLDEST_MANIFEST_VERSION = 1;
  23
  24         /**
  25          * Bump whenever the registration cache needs resetting
  26          */
  27         const CACHE_VERSION = 1;
  28
  29         /**
  30          * Special key that defines the merge strategy
  31          *
  32          * @since 1.26
  33          */
  34         const MERGE_STRATEGY = '_merge_strategy';
  35
  36         /**
  37          * @var BagOStuff
  38          */
  39         protected $cache;
  40
  41         /**
  42          * Array of loaded things, keyed by name, values are credits information
  43          *
  44          * @var array
  45          */
  46         private $loaded = array();
  47
  48         /**
  49          * List of paths that should be loaded
  50          *
  51          * @var array
  52          */
  53         protected $queued = array();
  54
  55         /**
  56          * Items in the JSON file that aren't being
  57          * set as globals
  58          *
  59          * @var array
  60          */
  61         protected $attributes = array();
  62
  63         /**
  64          * @var ExtensionRegistry
  65          */
  66         private static $instance;
  67
  68         /**
  69          * @return ExtensionRegistry
  70          */
  71         public static function getInstance() {
  72                 if ( self::$instance === null ) {
  73                         self::$instance = new self();
  74                 }
  75
  76                 return self::$instance;
  77         }
  78
  79         public function __construct() {
  80                 // We use a try/catch instead of the $fallback parameter because
  81                 // we don't want to fail here if $wgObjectCaches is not configured
  82                 // properly for APC setup
  83                 try {
  84                         $this->cache = ObjectCache::newAccelerator();
  85                 } catch ( MWException $e ) {
  86                         $this->cache = new EmptyBagOStuff();
  87                 }
  88         }
  89
  90         /**
  91          * @param string $path Absolute path to the JSON file
  92          */
  93         public function queue( $path ) {
  94                 global $wgExtensionInfoMTime;
  95
  96                 $mtime = $wgExtensionInfoMTime;
  97                 if ( $mtime === false ) {
  98                         if ( file_exists( $path ) ) {
  99                                 $mtime = filemtime( $path );
 100                         } else {
 101                                 throw new Exception( "$path does not exist!" );
 102                         }
 103                         if ( !$mtime ) {
 104                                 $err = error_get_last();
 105                                 throw new Exception( "Couldn't stat $path: {$err['message']}" );
 106                         }
 107                 }
 108                 $this->queued[$path] = $mtime;
 109         }
 110
 111         public function loadFromQueue() {
 112                 if ( !$this->queued ) {
 113                         return;
 114                 }
 115
 116                 // See if this queue is in APC
 117                 $key = wfMemcKey( 'registration', md5( json_encode( $this->queued ) ), self::CACHE_VERSION );
 118                 $data = $this->cache->get( $key );
 119                 if ( $data ) {
 120                         $this->exportExtractedData( $data );
 121                 } else {
 122                         $data = $this->readFromQueue( $this->queued );
 123                         $this->exportExtractedData( $data );
 124                         // Do this late since we don't want to extract it since we already
 125                         // did that, but it should be cached
 126                         $data['globals']['wgAutoloadClasses'] += $data['autoload'];
 127                         unset( $data['autoload'] );
 128                         $this->cache->set( $key, $data, 60 * 60 * 24 );
 129                 }
 130                 $this->queued = array();
 131         }
 132
 133         /**
 134          * Get the current load queue. Not intended to be used
 135          * outside of the installer.
 136          *
 137          * @return array
 138          */
 139         public function getQueue() {
 140                 return $this->queued;
 141         }
 142
 143         /**
 144          * Clear the current load queue. Not intended to be used
 145          * outside of the installer.
 146          */
 147         public function clearQueue() {
 148                 $this->queued = array();
 149         }
 150
 151         /**
 152          * Process a queue of extensions and return their extracted data
 153          *
 154          * @param array $queue keys are filenames, values are ignored
 155          * @return array extracted info
 156          * @throws Exception
 157          */
 158         public function readFromQueue( array $queue ) {
 159                 $autoloadClasses = array();
 160                 $processor = new ExtensionProcessor();
 161                 foreach ( $queue as $path => $mtime ) {
 162                         $json = file_get_contents( $path );
 163                         if ( $json === false ) {
 164                                 throw new Exception( "Unable to read $path, does it exist?" );
 165                         }
 166                         $info = json_decode( $json, /* $assoc = */ true );
 167                         if ( !is_array( $info ) ) {
 168                                 throw new Exception( "$path is not a valid JSON file." );
 169                         }
 170                         if ( !isset( $info['manifest_version'] ) ) {
 171                                 // For backwards-compatability, assume a version of 1
 172                                 $info['manifest_version'] = 1;
 173                         }
 174                         $version = $info['manifest_version'];
 175                         if ( $version < self::OLDEST_MANIFEST_VERSION || $version > self::MANIFEST_VERSION ) {
 176                                 throw new Exception( "$path: unsupported manifest_version: {$version}" );
 177                         }
 178                         $autoload = $this->processAutoLoader( dirname( $path ), $info );
 179                         // Set up the autoloader now so custom processors will work
 180                         $GLOBALS['wgAutoloadClasses'] += $autoload;
 181                         $autoloadClasses += $autoload;
 182                         $processor->extractInfo( $path, $info, $version );
 183                 }
 184                 $data = $processor->getExtractedInfo();
 185                 // Need to set this so we can += to it later
 186                 $data['globals']['wgAutoloadClasses'] = array();
 187                 foreach ( $data['credits'] as $credit ) {
 188                         $data['globals']['wgExtensionCredits'][$credit['type']][] = $credit;
 189                 }
 190                 $data['globals']['wgExtensionCredits'][self::MERGE_STRATEGY] = 'array_merge_recursive';
 191                 $data['autoload'] = $autoloadClasses;
 192                 return $data;
 193         }
 194
 195         protected function exportExtractedData( array $info ) {
 196                 foreach ( $info['globals'] as $key => $val ) {
 197                         // If a merge strategy is set, read it and remove it from the value
 198                         // so it doesn't accidentally end up getting set.
 199                         // Need to check $val is an array for PHP 5.3 which will return
 200                         // true on isset( 'string'['foo'] ).
 201                         if ( isset( $val[self::MERGE_STRATEGY] ) && is_array( $val ) ) {
 202                                 $mergeStrategy = $val[self::MERGE_STRATEGY];
 203                                 unset( $val[self::MERGE_STRATEGY] );
 204                         } else {
 205                                 $mergeStrategy = 'array_merge';
 206                         }
 207
 208                         // Optimistic: If the global is not set, or is an empty array, replace it entirely.
 209                         // Will be O(1) performance.
 210                         if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
 211                                 $GLOBALS[$key] = $val;
 212                                 continue;
 213                         }
 214
 215                         if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
 216                                 // config setting that has already been overridden, don't set it
 217                                 continue;
 218                         }
 219
 220                         switch ( $mergeStrategy ) {
 221                                 case 'array_merge_recursive':
 222                                         $GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
 223                                         break;
 224                                 case 'array_plus_2d':
 225                                         // First merge items that are in both arrays
 226                                         foreach ( $GLOBALS[$key] as $name => &$groupVal ) {
 227                                                 if ( isset( $val[$name] ) ) {
 228                                                         $groupVal += $val[$name];
 229                                                 }
 230                                         }
 231                                         // Now add items that didn't exist yet
 232                                         $GLOBALS[$key] += $val;
 233                                         break;
 234                                 case 'array_plus':
 235                                         $GLOBALS[$key] = $val + $GLOBALS[$key];
 236                                         break;
 237                                 case 'array_merge':
 238                                         $GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
 239                                         break;
 240                                 default:
 241                                         throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
 242                         }
 243                 }
 244
 245                 foreach ( $info['defines'] as $name => $val ) {
 246                         define( $name, $val );
 247                 }
 248                 foreach ( $info['callbacks'] as $cb ) {
 249                         call_user_func( $cb );
 250                 }
 251
 252                 $this->loaded += $info['credits'];
 253
 254                 if ( $info['attributes'] ) {
 255                         if ( !$this->attributes ) {
 256                                 $this->attributes = $info['attributes'];
 257                         } else {
 258                                 $this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
 259                         }
 260                 }
 261         }
 262
 263         /**
 264          * Loads and processes the given JSON file without delay
 265          *
 266          * If some extensions are already queued, this will load
 267          * those as well.
 268          *
 269          * @param string $path Absolute path to the JSON file
 270          */
 271         public function load( $path ) {
 272                 $this->loadFromQueue(); // First clear the queue
 273                 $this->queue( $path );
 274                 $this->loadFromQueue();
 275         }
 276
 277         /**
 278          * Whether a thing has been loaded
 279          * @param string $name
 280          * @return bool
 281          */
 282         public function isLoaded( $name ) {
 283                 return isset( $this->loaded[$name] );
 284         }
 285
 286         /**
 287          * @param string $name
 288          * @return array
 289          */
 290         public function getAttribute( $name ) {
 291                 if ( isset( $this->attributes[$name] ) ) {
 292                         return $this->attributes[$name];
 293                 } else {
 294                         return array();
 295                 }
 296         }
 297
 298         /**
 299          * Get information about all things
 300          *
 301          * @return array
 302          */
 303         public function getAllThings() {
 304                 return $this->loaded;
 305         }
 306
 307         /**
 308          * Mark a thing as loaded
 309          *
 310          * @param string $name
 311          * @param array $credits
 312          */
 313         protected function markLoaded( $name, array $credits ) {
 314                 $this->loaded[$name] = $credits;
 315         }
 316
 317         /**
 318          * Register classes with the autoloader
 319          *
 320          * @param string $dir
 321          * @param array $info
 322          * @return array
 323          */
 324         protected function processAutoLoader( $dir, array $info ) {
 325                 if ( isset( $info['AutoloadClasses'] ) ) {
 326                         // Make paths absolute, relative to the JSON file
 327                         return array_map( function( $file ) use ( $dir ) {
 328                                 return "$dir/$file";
 329                         }, $info['AutoloadClasses'] );
 330                 } else {
 331                         return array();
 332                 }
 333         }
 334 }