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