includes/registration/ExtensionRegistry.php

   1 <?php
   2
   3 use MediaWiki\MediaWikiServices;
   4
   5 /**
   6  * ExtensionRegistry class
   7  *
   8  * The Registry loads JSON files, and uses a Processor
   9  * to extract information from them. It also registers
  10  * classes with the autoloader.
  11  *
  12  * @since 1.25
  13  */
  14 class ExtensionRegistry {
  15
  16         /**
  17          * "requires" key that applies to MediaWiki core/$wgVersion
  18          */
  19         const MEDIAWIKI_CORE = 'MediaWiki';
  20
  21         /**
  22          * Version of the highest supported manifest version
  23          */
  24         const MANIFEST_VERSION = 2;
  25
  26         /**
  27          * Version of the oldest supported manifest version
  28          */
  29         const OLDEST_MANIFEST_VERSION = 1;
  30
  31         /**
  32          * Bump whenever the registration cache needs resetting
  33          */
  34         const CACHE_VERSION = 5;
  35
  36         /**
  37          * Special key that defines the merge strategy
  38          *
  39          * @since 1.26
  40          */
  41         const MERGE_STRATEGY = '_merge_strategy';
  42
  43         /**
  44          * Array of loaded things, keyed by name, values are credits information
  45          *
  46          * @var array
  47          */
  48         private $loaded = [];
  49
  50         /**
  51          * List of paths that should be loaded
  52          *
  53          * @var array
  54          */
  55         protected $queued = [];
  56
  57         /**
  58          * Whether we are done loading things
  59          *
  60          * @var bool
  61          */
  62         private $finished = false;
  63
  64         /**
  65          * Items in the JSON file that aren't being
  66          * set as globals
  67          *
  68          * @var array
  69          */
  70         protected $attributes = [];
  71
  72         /**
  73          * @var ExtensionRegistry
  74          */
  75         private static $instance;
  76
  77         /**
  78          * @return ExtensionRegistry
  79          */
  80         public static function getInstance() {
  81                 if ( self::$instance === null ) {
  82                         self::$instance = new self();
  83                 }
  84
  85                 return self::$instance;
  86         }
  87
  88         /**
  89          * @param string $path Absolute path to the JSON file
  90          */
  91         public function queue( $path ) {
  92                 global $wgExtensionInfoMTime;
  93
  94                 $mtime = $wgExtensionInfoMTime;
  95                 if ( $mtime === false ) {
  96                         if ( file_exists( $path ) ) {
  97                                 $mtime = filemtime( $path );
  98                         } else {
  99                                 throw new Exception( "$path does not exist!" );
 100                         }
 101                         if ( !$mtime ) {
 102                                 $err = error_get_last();
 103                                 throw new Exception( "Couldn't stat $path: {$err['message']}" );
 104                         }
 105                 }
 106                 $this->queued[$path] = $mtime;
 107         }
 108
 109         /**
 110          * @throws MWException If the queue is already marked as finished (no further things should
 111          *  be loaded then).
 112          */
 113         public function loadFromQueue() {
 114                 global $wgVersion;
 115                 if ( !$this->queued ) {
 116                         return;
 117                 }
 118
 119                 if ( $this->finished ) {
 120                         throw new MWException(
 121                                 "The following paths tried to load late: "
 122                                 . implode( ', ', array_keys( $this->queued ) )
 123                         );
 124                 }
 125
 126                 // A few more things to vary the cache on
 127                 $versions = [
 128                         'registration' => self::CACHE_VERSION,
 129                         'mediawiki' => $wgVersion
 130                 ];
 131
 132                 // We use a try/catch because we don't want to fail here
 133                 // if $wgObjectCaches is not configured properly for APC setup
 134                 try {
 135                         $cache = MediaWikiServices::getInstance()->getLocalServerObjectCache();
 136                 } catch ( MWException $e ) {
 137                         $cache = new EmptyBagOStuff();
 138                 }
 139                 // See if this queue is in APC
 140                 $key = wfMemcKey(
 141                         'registration',
 142                         md5( json_encode( $this->queued + $versions ) )
 143                 );
 144                 $data = $cache->get( $key );
 145                 if ( $data ) {
 146                         $this->exportExtractedData( $data );
 147                 } else {
 148                         $data = $this->readFromQueue( $this->queued );
 149                         $this->exportExtractedData( $data );
 150                         // Do this late since we don't want to extract it since we already
 151                         // did that, but it should be cached
 152                         $data['globals']['wgAutoloadClasses'] += $data['autoload'];
 153                         unset( $data['autoload'] );
 154                         $cache->set( $key, $data, 60 * 60 * 24 );
 155                 }
 156                 $this->queued = [];
 157         }
 158
 159         /**
 160          * Get the current load queue. Not intended to be used
 161          * outside of the installer.
 162          *
 163          * @return array
 164          */
 165         public function getQueue() {
 166                 return $this->queued;
 167         }
 168
 169         /**
 170          * Clear the current load queue. Not intended to be used
 171          * outside of the installer.
 172          */
 173         public function clearQueue() {
 174                 $this->queued = [];
 175         }
 176
 177         /**
 178          * After this is called, no more extensions can be loaded
 179          *
 180          * @since 1.29
 181          */
 182         public function finish() {
 183                 $this->finished = true;
 184         }
 185
 186         /**
 187          * Process a queue of extensions and return their extracted data
 188          *
 189          * @param array $queue keys are filenames, values are ignored
 190          * @return array extracted info
 191          * @throws Exception
 192          */
 193         public function readFromQueue( array $queue ) {
 194                 global $wgVersion;
 195                 $autoloadClasses = [];
 196                 $autoloaderPaths = [];
 197                 $processor = new ExtensionProcessor();
 198                 $versionChecker = new VersionChecker( $wgVersion );
 199                 $extDependencies = [];
 200                 $incompatible = [];
 201                 foreach ( $queue as $path => $mtime ) {
 202                         $json = file_get_contents( $path );
 203                         if ( $json === false ) {
 204                                 throw new Exception( "Unable to read $path, does it exist?" );
 205                         }
 206                         $info = json_decode( $json, /* $assoc = */ true );
 207                         if ( !is_array( $info ) ) {
 208                                 throw new Exception( "$path is not a valid JSON file." );
 209                         }
 210
 211                         if ( !isset( $info['manifest_version'] ) ) {
 212                                 // For backwards-compatability, assume a version of 1
 213                                 $info['manifest_version'] = 1;
 214                         }
 215                         $version = $info['manifest_version'];
 216                         if ( $version < self::OLDEST_MANIFEST_VERSION || $version > self::MANIFEST_VERSION ) {
 217                                 $incompatible[] = "$path: unsupported manifest_version: {$version}";
 218                         }
 219
 220                         $autoload = $this->processAutoLoader( dirname( $path ), $info );
 221                         // Set up the autoloader now so custom processors will work
 222                         $GLOBALS['wgAutoloadClasses'] += $autoload;
 223                         $autoloadClasses += $autoload;
 224
 225                         // get all requirements/dependencies for this extension
 226                         $requires = $processor->getRequirements( $info );
 227
 228                         // validate the information needed and add the requirements
 229                         if ( is_array( $requires ) && $requires && isset( $info['name'] ) ) {
 230                                 $extDependencies[$info['name']] = $requires;
 231                         }
 232
 233                         // Get extra paths for later inclusion
 234                         $autoloaderPaths = array_merge( $autoloaderPaths,
 235                                 $processor->getExtraAutoloaderPaths( dirname( $path ), $info ) );
 236                         // Compatible, read and extract info
 237                         $processor->extractInfo( $path, $info, $version );
 238                 }
 239                 $data = $processor->getExtractedInfo();
 240
 241                 // check for incompatible extensions
 242                 $incompatible = array_merge(
 243                         $incompatible,
 244                         $versionChecker
 245                                 ->setLoadedExtensionsAndSkins( $data['credits'] )
 246                                 ->checkArray( $extDependencies )
 247                 );
 248
 249                 if ( $incompatible ) {
 250                         if ( count( $incompatible ) === 1 ) {
 251                                 throw new Exception( $incompatible[0] );
 252                         } else {
 253                                 throw new Exception( implode( "\n", $incompatible ) );
 254                         }
 255                 }
 256
 257                 // Need to set this so we can += to it later
 258                 $data['globals']['wgAutoloadClasses'] = [];
 259                 $data['autoload'] = $autoloadClasses;
 260                 $data['autoloaderPaths'] = $autoloaderPaths;
 261                 return $data;
 262         }
 263
 264         protected function exportExtractedData( array $info ) {
 265                 foreach ( $info['globals'] as $key => $val ) {
 266                         // If a merge strategy is set, read it and remove it from the value
 267                         // so it doesn't accidentally end up getting set.
 268                         if ( is_array( $val ) && isset( $val[self::MERGE_STRATEGY] ) ) {
 269                                 $mergeStrategy = $val[self::MERGE_STRATEGY];
 270                                 unset( $val[self::MERGE_STRATEGY] );
 271                         } else {
 272                                 $mergeStrategy = 'array_merge';
 273                         }
 274
 275                         // Optimistic: If the global is not set, or is an empty array, replace it entirely.
 276                         // Will be O(1) performance.
 277                         if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
 278                                 $GLOBALS[$key] = $val;
 279                                 continue;
 280                         }
 281
 282                         if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
 283                                 // config setting that has already been overridden, don't set it
 284                                 continue;
 285                         }
 286
 287                         switch ( $mergeStrategy ) {
 288                                 case 'array_merge_recursive':
 289                                         $GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
 290                                         break;
 291                                 case 'array_replace_recursive':
 292                                         $GLOBALS[$key] = array_replace_recursive( $GLOBALS[$key], $val );
 293                                         break;
 294                                 case 'array_plus_2d':
 295                                         $GLOBALS[$key] = wfArrayPlus2d( $GLOBALS[$key], $val );
 296                                         break;
 297                                 case 'array_plus':
 298                                         $GLOBALS[$key] += $val;
 299                                         break;
 300                                 case 'array_merge':
 301                                         $GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
 302                                         break;
 303                                 default:
 304                                         throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
 305                         }
 306                 }
 307
 308                 foreach ( $info['defines'] as $name => $val ) {
 309                         define( $name, $val );
 310                 }
 311                 foreach ( $info['autoloaderPaths'] as $path ) {
 312                         require_once $path;
 313                 }
 314
 315                 $this->loaded += $info['credits'];
 316                 if ( $info['attributes'] ) {
 317                         if ( !$this->attributes ) {
 318                                 $this->attributes = $info['attributes'];
 319                         } else {
 320                                 $this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
 321                         }
 322                 }
 323
 324                 foreach ( $info['callbacks'] as $name => $cb ) {
 325                         call_user_func( $cb, $info['credits'][$name] );
 326                 }
 327         }
 328
 329         /**
 330          * Loads and processes the given JSON file without delay
 331          *
 332          * If some extensions are already queued, this will load
 333          * those as well.
 334          *
 335          * @param string $path Absolute path to the JSON file
 336          */
 337         public function load( $path ) {
 338                 $this->loadFromQueue(); // First clear the queue
 339                 $this->queue( $path );
 340                 $this->loadFromQueue();
 341         }
 342
 343         /**
 344          * Whether a thing has been loaded
 345          * @param string $name
 346          * @return bool
 347          */
 348         public function isLoaded( $name ) {
 349                 return isset( $this->loaded[$name] );
 350         }
 351
 352         /**
 353          * @param string $name
 354          * @return array
 355          */
 356         public function getAttribute( $name ) {
 357                 if ( isset( $this->attributes[$name] ) ) {
 358                         return $this->attributes[$name];
 359                 } else {
 360                         return [];
 361                 }
 362         }
 363
 364         /**
 365          * Get information about all things
 366          *
 367          * @return array
 368          */
 369         public function getAllThings() {
 370                 return $this->loaded;
 371         }
 372
 373         /**
 374          * Mark a thing as loaded
 375          *
 376          * @param string $name
 377          * @param array $credits
 378          */
 379         protected function markLoaded( $name, array $credits ) {
 380                 $this->loaded[$name] = $credits;
 381         }
 382
 383         /**
 384          * Register classes with the autoloader
 385          *
 386          * @param string $dir
 387          * @param array $info
 388          * @return array
 389          */
 390         protected function processAutoLoader( $dir, array $info ) {
 391                 if ( isset( $info['AutoloadClasses'] ) ) {
 392                         // Make paths absolute, relative to the JSON file
 393                         return array_map( function( $file ) use ( $dir ) {
 394                                 return "$dir/$file";
 395                         }, $info['AutoloadClasses'] );
 396                 } else {
 397                         return [];
 398                 }
 399         }
 400 }