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 = 3;
  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          * @var BagOStuff
  45          */
  46         protected $cache;
  47
  48         /**
  49          * Array of loaded things, keyed by name, values are credits information
  50          *
  51          * @var array
  52          */
  53         private $loaded = [];
  54
  55         /**
  56          * List of paths that should be loaded
  57          *
  58          * @var array
  59          */
  60         protected $queued = [];
  61
  62         /**
  63          * Whether we are done loading things
  64          *
  65          * @var bool
  66          */
  67         private $finished = false;
  68
  69         /**
  70          * Items in the JSON file that aren't being
  71          * set as globals
  72          *
  73          * @var array
  74          */
  75         protected $attributes = [];
  76
  77         /**
  78          * @var ExtensionRegistry
  79          */
  80         private static $instance;
  81
  82         /**
  83          * @return ExtensionRegistry
  84          */
  85         public static function getInstance() {
  86                 if ( self::$instance === null ) {
  87                         self::$instance = new self();
  88                 }
  89
  90                 return self::$instance;
  91         }
  92
  93         public function __construct() {
  94                 // We use a try/catch because we don't want to fail here
  95                 // if $wgObjectCaches is not configured properly for APC setup
  96                 try {
  97                         $this->cache = MediaWikiServices::getInstance()->getLocalServerObjectCache();
  98                 } catch ( MWException $e ) {
  99                         $this->cache = new EmptyBagOStuff();
 100                 }
 101         }
 102
 103         /**
 104          * @param string $path Absolute path to the JSON file
 105          */
 106         public function queue( $path ) {
 107                 global $wgExtensionInfoMTime;
 108
 109                 $mtime = $wgExtensionInfoMTime;
 110                 if ( $mtime === false ) {
 111                         if ( file_exists( $path ) ) {
 112                                 $mtime = filemtime( $path );
 113                         } else {
 114                                 throw new Exception( "$path does not exist!" );
 115                         }
 116                         if ( !$mtime ) {
 117                                 $err = error_get_last();
 118                                 throw new Exception( "Couldn't stat $path: {$err['message']}" );
 119                         }
 120                 }
 121                 $this->queued[$path] = $mtime;
 122         }
 123
 124         /**
 125          * @throws MWException If the queue is already marked as finished (no further things should
 126          *  be loaded then).
 127          */
 128         public function loadFromQueue() {
 129                 global $wgVersion;
 130                 if ( !$this->queued ) {
 131                         return;
 132                 }
 133
 134                 if ( $this->finished ) {
 135                         throw new MWException(
 136                                 "The following paths tried to load late: "
 137                                 . implode( ', ', array_keys( $this->queued ) )
 138                         );
 139                 }
 140
 141                 // A few more things to vary the cache on
 142                 $versions = [
 143                         'registration' => self::CACHE_VERSION,
 144                         'mediawiki' => $wgVersion
 145                 ];
 146
 147                 // See if this queue is in APC
 148                 $key = wfMemcKey(
 149                         'registration',
 150                         md5( json_encode( $this->queued + $versions ) )
 151                 );
 152                 $data = $this->cache->get( $key );
 153                 if ( $data ) {
 154                         $this->exportExtractedData( $data );
 155                 } else {
 156                         $data = $this->readFromQueue( $this->queued );
 157                         $this->exportExtractedData( $data );
 158                         // Do this late since we don't want to extract it since we already
 159                         // did that, but it should be cached
 160                         $data['globals']['wgAutoloadClasses'] += $data['autoload'];
 161                         unset( $data['autoload'] );
 162                         $this->cache->set( $key, $data, 60 * 60 * 24 );
 163                 }
 164                 $this->queued = [];
 165         }
 166
 167         /**
 168          * Get the current load queue. Not intended to be used
 169          * outside of the installer.
 170          *
 171          * @return array
 172          */
 173         public function getQueue() {
 174                 return $this->queued;
 175         }
 176
 177         /**
 178          * Clear the current load queue. Not intended to be used
 179          * outside of the installer.
 180          */
 181         public function clearQueue() {
 182                 $this->queued = [];
 183         }
 184
 185         /**
 186          * After this is called, no more extensions can be loaded
 187          *
 188          * @since 1.29
 189          */
 190         public function finish() {
 191                 $this->finished = true;
 192         }
 193
 194         /**
 195          * Process a queue of extensions and return their extracted data
 196          *
 197          * @param array $queue keys are filenames, values are ignored
 198          * @return array extracted info
 199          * @throws Exception
 200          */
 201         public function readFromQueue( array $queue ) {
 202                 global $wgVersion;
 203                 $autoloadClasses = [];
 204                 $autoloaderPaths = [];
 205                 $processor = new ExtensionProcessor();
 206                 $incompatible = [];
 207                 $coreVersionParser = new CoreVersionChecker( $wgVersion );
 208                 foreach ( $queue as $path => $mtime ) {
 209                         $json = file_get_contents( $path );
 210                         if ( $json === false ) {
 211                                 throw new Exception( "Unable to read $path, does it exist?" );
 212                         }
 213                         $info = json_decode( $json, /* $assoc = */ true );
 214                         if ( !is_array( $info ) ) {
 215                                 throw new Exception( "$path is not a valid JSON file." );
 216                         }
 217
 218                         // Check any constraints against MediaWiki core
 219                         $requires = $processor->getRequirements( $info );
 220                         if ( isset( $requires[self::MEDIAWIKI_CORE] )
 221                                 && !$coreVersionParser->check( $requires[self::MEDIAWIKI_CORE] )
 222                         ) {
 223                                 // Doesn't match, mark it as incompatible.
 224                                 $incompatible[] = "{$info['name']} is not compatible with the current "
 225                                         . "MediaWiki core (version {$wgVersion}), it requires: " . $requires[self::MEDIAWIKI_CORE]
 226                                         . '.';
 227                                 continue;
 228                         }
 229
 230                         if ( !isset( $info['manifest_version'] ) ) {
 231                                 // For backwards-compatability, assume a version of 1
 232                                 $info['manifest_version'] = 1;
 233                         }
 234                         $version = $info['manifest_version'];
 235                         if ( $version < self::OLDEST_MANIFEST_VERSION || $version > self::MANIFEST_VERSION ) {
 236                                 throw new Exception( "$path: unsupported manifest_version: {$version}" );
 237                         }
 238
 239                         $autoload = $this->processAutoLoader( dirname( $path ), $info );
 240                         // Set up the autoloader now so custom processors will work
 241                         $GLOBALS['wgAutoloadClasses'] += $autoload;
 242                         $autoloadClasses += $autoload;
 243
 244                         // Get extra paths for later inclusion
 245                         $autoloaderPaths = array_merge( $autoloaderPaths,
 246                                 $processor->getExtraAutoloaderPaths( dirname( $path ), $info ) );
 247                         // Compatible, read and extract info
 248                         $processor->extractInfo( $path, $info, $version );
 249                 }
 250                 if ( $incompatible ) {
 251                         if ( count( $incompatible ) === 1 ) {
 252                                 throw new Exception( $incompatible[0] );
 253                         } else {
 254                                 throw new Exception( implode( "\n", $incompatible ) );
 255                         }
 256                 }
 257                 $data = $processor->getExtractedInfo();
 258                 // Need to set this so we can += to it later
 259                 $data['globals']['wgAutoloadClasses'] = [];
 260                 $data['autoload'] = $autoloadClasses;
 261                 $data['autoloaderPaths'] = $autoloaderPaths;
 262                 return $data;
 263         }
 264
 265         protected function exportExtractedData( array $info ) {
 266                 foreach ( $info['globals'] as $key => $val ) {
 267                         // If a merge strategy is set, read it and remove it from the value
 268                         // so it doesn't accidentally end up getting set.
 269                         if ( is_array( $val ) && isset( $val[self::MERGE_STRATEGY] ) ) {
 270                                 $mergeStrategy = $val[self::MERGE_STRATEGY];
 271                                 unset( $val[self::MERGE_STRATEGY] );
 272                         } else {
 273                                 $mergeStrategy = 'array_merge';
 274                         }
 275
 276                         // Optimistic: If the global is not set, or is an empty array, replace it entirely.
 277                         // Will be O(1) performance.
 278                         if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
 279                                 $GLOBALS[$key] = $val;
 280                                 continue;
 281                         }
 282
 283                         if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
 284                                 // config setting that has already been overridden, don't set it
 285                                 continue;
 286                         }
 287
 288                         switch ( $mergeStrategy ) {
 289                                 case 'array_merge_recursive':
 290                                         $GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
 291                                         break;
 292                                 case 'array_replace_recursive':
 293                                         $GLOBALS[$key] = array_replace_recursive( $GLOBALS[$key], $val );
 294                                         break;
 295                                 case 'array_plus_2d':
 296                                         $GLOBALS[$key] = wfArrayPlus2d( $GLOBALS[$key], $val );
 297                                         break;
 298                                 case 'array_plus':
 299                                         $GLOBALS[$key] += $val;
 300                                         break;
 301                                 case 'array_merge':
 302                                         $GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
 303                                         break;
 304                                 default:
 305                                         throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
 306                         }
 307                 }
 308
 309                 foreach ( $info['defines'] as $name => $val ) {
 310                         define( $name, $val );
 311                 }
 312                 foreach ( $info['autoloaderPaths'] as $path ) {
 313                         require_once $path;
 314                 }
 315                 foreach ( $info['callbacks'] as $cb ) {
 316                         call_user_func( $cb );
 317                 }
 318
 319                 $this->loaded += $info['credits'];
 320                 if ( $info['attributes'] ) {
 321                         if ( !$this->attributes ) {
 322                                 $this->attributes = $info['attributes'];
 323                         } else {
 324                                 $this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
 325                         }
 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 }