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 = 6;
  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
 102                         if ( $mtime === false ) {
 103                                 $err = error_get_last();
 104                                 throw new Exception( "Couldn't stat $path: {$err['message']}" );
 105                         }
 106                 }
 107                 $this->queued[$path] = $mtime;
 108         }
 109
 110         /**
 111          * @throws MWException If the queue is already marked as finished (no further things should
 112          *  be loaded then).
 113          */
 114         public function loadFromQueue() {
 115                 global $wgVersion, $wgDevelopmentWarnings;
 116                 if ( !$this->queued ) {
 117                         return;
 118                 }
 119
 120                 if ( $this->finished ) {
 121                         throw new MWException(
 122                                 "The following paths tried to load late: "
 123                                 . implode( ', ', array_keys( $this->queued ) )
 124                         );
 125                 }
 126
 127                 // A few more things to vary the cache on
 128                 $versions = [
 129                         'registration' => self::CACHE_VERSION,
 130                         'mediawiki' => $wgVersion
 131                 ];
 132
 133                 // We use a try/catch because we don't want to fail here
 134                 // if $wgObjectCaches is not configured properly for APC setup
 135                 try {
 136                         $cache = MediaWikiServices::getInstance()->getLocalServerObjectCache();
 137                 } catch ( MWException $e ) {
 138                         $cache = new EmptyBagOStuff();
 139                 }
 140                 // See if this queue is in APC
 141                 $key = $cache->makeKey(
 142                         'registration',
 143                         md5( json_encode( $this->queued + $versions ) )
 144                 );
 145                 $data = $cache->get( $key );
 146                 if ( $data ) {
 147                         $this->exportExtractedData( $data );
 148                 } else {
 149                         $data = $this->readFromQueue( $this->queued );
 150                         $this->exportExtractedData( $data );
 151                         // Do this late since we don't want to extract it since we already
 152                         // did that, but it should be cached
 153                         $data['globals']['wgAutoloadClasses'] += $data['autoload'];
 154                         unset( $data['autoload'] );
 155                         if ( !( $data['warnings'] && $wgDevelopmentWarnings ) ) {
 156                                 // If there were no warnings that were shown, cache it
 157                                 $cache->set( $key, $data, 60 * 60 * 24 );
 158                         }
 159                 }
 160                 $this->queued = [];
 161         }
 162
 163         /**
 164          * Get the current load queue. Not intended to be used
 165          * outside of the installer.
 166          *
 167          * @return array
 168          */
 169         public function getQueue() {
 170                 return $this->queued;
 171         }
 172
 173         /**
 174          * Clear the current load queue. Not intended to be used
 175          * outside of the installer.
 176          */
 177         public function clearQueue() {
 178                 $this->queued = [];
 179         }
 180
 181         /**
 182          * After this is called, no more extensions can be loaded
 183          *
 184          * @since 1.29
 185          */
 186         public function finish() {
 187                 $this->finished = true;
 188         }
 189
 190         /**
 191          * Process a queue of extensions and return their extracted data
 192          *
 193          * @param array $queue keys are filenames, values are ignored
 194          * @return array extracted info
 195          * @throws Exception
 196          */
 197         public function readFromQueue( array $queue ) {
 198                 global $wgVersion;
 199                 $autoloadClasses = [];
 200                 $autoloaderPaths = [];
 201                 $processor = new ExtensionProcessor();
 202                 $versionChecker = new VersionChecker( $wgVersion );
 203                 $extDependencies = [];
 204                 $incompatible = [];
 205                 $warnings = false;
 206                 foreach ( $queue as $path => $mtime ) {
 207                         $json = file_get_contents( $path );
 208                         if ( $json === false ) {
 209                                 throw new Exception( "Unable to read $path, does it exist?" );
 210                         }
 211                         $info = json_decode( $json, /* $assoc = */ true );
 212                         if ( !is_array( $info ) ) {
 213                                 throw new Exception( "$path is not a valid JSON file." );
 214                         }
 215
 216                         if ( !isset( $info['manifest_version'] ) ) {
 217                                 wfDeprecated(
 218                                         "{$info['name']}'s extension.json or skin.json does not have manifest_version",
 219                                         '1.29'
 220                                 );
 221                                 $warnings = true;
 222                                 // For backwards-compatability, assume a version of 1
 223                                 $info['manifest_version'] = 1;
 224                         }
 225                         $version = $info['manifest_version'];
 226                         if ( $version < self::OLDEST_MANIFEST_VERSION || $version > self::MANIFEST_VERSION ) {
 227                                 $incompatible[] = "$path: unsupported manifest_version: {$version}";
 228                         }
 229
 230                         $autoload = $this->processAutoLoader( dirname( $path ), $info );
 231                         // Set up the autoloader now so custom processors will work
 232                         $GLOBALS['wgAutoloadClasses'] += $autoload;
 233                         $autoloadClasses += $autoload;
 234
 235                         // get all requirements/dependencies for this extension
 236                         $requires = $processor->getRequirements( $info );
 237
 238                         // validate the information needed and add the requirements
 239                         if ( is_array( $requires ) && $requires && isset( $info['name'] ) ) {
 240                                 $extDependencies[$info['name']] = $requires;
 241                         }
 242
 243                         // Get extra paths for later inclusion
 244                         $autoloaderPaths = array_merge( $autoloaderPaths,
 245                                 $processor->getExtraAutoloaderPaths( dirname( $path ), $info ) );
 246                         // Compatible, read and extract info
 247                         $processor->extractInfo( $path, $info, $version );
 248                 }
 249                 $data = $processor->getExtractedInfo();
 250                 $data['warnings'] = $warnings;
 251
 252                 // check for incompatible extensions
 253                 $incompatible = array_merge(
 254                         $incompatible,
 255                         $versionChecker
 256                                 ->setLoadedExtensionsAndSkins( $data['credits'] )
 257                                 ->checkArray( $extDependencies )
 258                 );
 259
 260                 if ( $incompatible ) {
 261                         if ( count( $incompatible ) === 1 ) {
 262                                 throw new Exception( $incompatible[0] );
 263                         } else {
 264                                 throw new Exception( implode( "\n", $incompatible ) );
 265                         }
 266                 }
 267
 268                 // Need to set this so we can += to it later
 269                 $data['globals']['wgAutoloadClasses'] = [];
 270                 $data['autoload'] = $autoloadClasses;
 271                 $data['autoloaderPaths'] = $autoloaderPaths;
 272                 return $data;
 273         }
 274
 275         protected function exportExtractedData( array $info ) {
 276                 foreach ( $info['globals'] as $key => $val ) {
 277                         // If a merge strategy is set, read it and remove it from the value
 278                         // so it doesn't accidentally end up getting set.
 279                         if ( is_array( $val ) && isset( $val[self::MERGE_STRATEGY] ) ) {
 280                                 $mergeStrategy = $val[self::MERGE_STRATEGY];
 281                                 unset( $val[self::MERGE_STRATEGY] );
 282                         } else {
 283                                 $mergeStrategy = 'array_merge';
 284                         }
 285
 286                         // Optimistic: If the global is not set, or is an empty array, replace it entirely.
 287                         // Will be O(1) performance.
 288                         if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
 289                                 $GLOBALS[$key] = $val;
 290                                 continue;
 291                         }
 292
 293                         if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
 294                                 // config setting that has already been overridden, don't set it
 295                                 continue;
 296                         }
 297
 298                         switch ( $mergeStrategy ) {
 299                                 case 'array_merge_recursive':
 300                                         $GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
 301                                         break;
 302                                 case 'array_replace_recursive':
 303                                         $GLOBALS[$key] = array_replace_recursive( $GLOBALS[$key], $val );
 304                                         break;
 305                                 case 'array_plus_2d':
 306                                         $GLOBALS[$key] = wfArrayPlus2d( $GLOBALS[$key], $val );
 307                                         break;
 308                                 case 'array_plus':
 309                                         $GLOBALS[$key] += $val;
 310                                         break;
 311                                 case 'array_merge':
 312                                         $GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
 313                                         break;
 314                                 default:
 315                                         throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
 316                         }
 317                 }
 318
 319                 foreach ( $info['defines'] as $name => $val ) {
 320                         define( $name, $val );
 321                 }
 322                 foreach ( $info['autoloaderPaths'] as $path ) {
 323                         require_once $path;
 324                 }
 325
 326                 $this->loaded += $info['credits'];
 327                 if ( $info['attributes'] ) {
 328                         if ( !$this->attributes ) {
 329                                 $this->attributes = $info['attributes'];
 330                         } else {
 331                                 $this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
 332                         }
 333                 }
 334
 335                 foreach ( $info['callbacks'] as $name => $cb ) {
 336                         if ( !is_callable( $cb ) ) {
 337                                 if ( is_array( $cb ) ) {
 338                                         $cb = '[ ' . implode( ', ', $cb ) . ' ]';
 339                                 }
 340                                 throw new UnexpectedValueException( "callback '$cb' is not callable" );
 341                         }
 342                         call_user_func( $cb, $info['credits'][$name] );
 343                 }
 344         }
 345
 346         /**
 347          * Loads and processes the given JSON file without delay
 348          *
 349          * If some extensions are already queued, this will load
 350          * those as well.
 351          *
 352          * @param string $path Absolute path to the JSON file
 353          */
 354         public function load( $path ) {
 355                 $this->loadFromQueue(); // First clear the queue
 356                 $this->queue( $path );
 357                 $this->loadFromQueue();
 358         }
 359
 360         /**
 361          * Whether a thing has been loaded
 362          * @param string $name
 363          * @return bool
 364          */
 365         public function isLoaded( $name ) {
 366                 return isset( $this->loaded[$name] );
 367         }
 368
 369         /**
 370          * @param string $name
 371          * @return array
 372          */
 373         public function getAttribute( $name ) {
 374                 if ( isset( $this->attributes[$name] ) ) {
 375                         return $this->attributes[$name];
 376                 } else {
 377                         return [];
 378                 }
 379         }
 380
 381         /**
 382          * Get information about all things
 383          *
 384          * @return array
 385          */
 386         public function getAllThings() {
 387                 return $this->loaded;
 388         }
 389
 390         /**
 391          * Mark a thing as loaded
 392          *
 393          * @param string $name
 394          * @param array $credits
 395          */
 396         protected function markLoaded( $name, array $credits ) {
 397                 $this->loaded[$name] = $credits;
 398         }
 399
 400         /**
 401          * Register classes with the autoloader
 402          *
 403          * @param string $dir
 404          * @param array $info
 405          * @return array
 406          */
 407         protected function processAutoLoader( $dir, array $info ) {
 408                 if ( isset( $info['AutoloadClasses'] ) ) {
 409                         // Make paths absolute, relative to the JSON file
 410                         return array_map( function ( $file ) use ( $dir ) {
 411                                 return "$dir/$file";
 412                         }, $info['AutoloadClasses'] );
 413                 } else {
 414                         return [];
 415                 }
 416         }
 417 }