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          * Items in the JSON file that aren't being
  64          * set as globals
  65          *
  66          * @var array
  67          */
  68         protected $attributes = [];
  69
  70         /**
  71          * @var ExtensionRegistry
  72          */
  73         private static $instance;
  74
  75         /**
  76          * @return ExtensionRegistry
  77          */
  78         public static function getInstance() {
  79                 if ( self::$instance === null ) {
  80                         self::$instance = new self();
  81                 }
  82
  83                 return self::$instance;
  84         }
  85
  86         public function __construct() {
  87                 // We use a try/catch instead of the $fallback parameter because
  88                 // we don't want to fail here if $wgObjectCaches is not configured
  89                 // properly for APC setup
  90                 try {
  91                         $this->cache = MediaWikiServices::getInstance()->getLocalServerObjectCache();
  92                 } catch ( MWException $e ) {
  93                         $this->cache = new EmptyBagOStuff();
  94                 }
  95         }
  96
  97         /**
  98          * @param string $path Absolute path to the JSON file
  99          */
 100         public function queue( $path ) {
 101                 global $wgExtensionInfoMTime;
 102
 103                 $mtime = $wgExtensionInfoMTime;
 104                 if ( $mtime === false ) {
 105                         if ( file_exists( $path ) ) {
 106                                 $mtime = filemtime( $path );
 107                         } else {
 108                                 throw new Exception( "$path does not exist!" );
 109                         }
 110                         if ( !$mtime ) {
 111                                 $err = error_get_last();
 112                                 throw new Exception( "Couldn't stat $path: {$err['message']}" );
 113                         }
 114                 }
 115                 $this->queued[$path] = $mtime;
 116         }
 117
 118         public function loadFromQueue() {
 119                 global $wgVersion;
 120                 if ( !$this->queued ) {
 121                         return;
 122                 }
 123
 124                 // A few more things to vary the cache on
 125                 $versions = [
 126                         'registration' => self::CACHE_VERSION,
 127                         'mediawiki' => $wgVersion
 128                 ];
 129
 130                 // See if this queue is in APC
 131                 $key = wfMemcKey(
 132                         'registration',
 133                         md5( json_encode( $this->queued + $versions ) )
 134                 );
 135                 $data = $this->cache->get( $key );
 136                 if ( $data ) {
 137                         $this->exportExtractedData( $data );
 138                 } else {
 139                         $data = $this->readFromQueue( $this->queued );
 140                         $this->exportExtractedData( $data );
 141                         // Do this late since we don't want to extract it since we already
 142                         // did that, but it should be cached
 143                         $data['globals']['wgAutoloadClasses'] += $data['autoload'];
 144                         unset( $data['autoload'] );
 145                         $this->cache->set( $key, $data, 60 * 60 * 24 );
 146                 }
 147                 $this->queued = [];
 148         }
 149
 150         /**
 151          * Get the current load queue. Not intended to be used
 152          * outside of the installer.
 153          *
 154          * @return array
 155          */
 156         public function getQueue() {
 157                 return $this->queued;
 158         }
 159
 160         /**
 161          * Clear the current load queue. Not intended to be used
 162          * outside of the installer.
 163          */
 164         public function clearQueue() {
 165                 $this->queued = [];
 166         }
 167
 168         /**
 169          * Process a queue of extensions and return their extracted data
 170          *
 171          * @param array $queue keys are filenames, values are ignored
 172          * @return array extracted info
 173          * @throws Exception
 174          */
 175         public function readFromQueue( array $queue ) {
 176                 global $wgVersion;
 177                 $autoloadClasses = [];
 178                 $autoloaderPaths = [];
 179                 $processor = new ExtensionProcessor();
 180                 $incompatible = [];
 181                 $coreVersionParser = new CoreVersionChecker( $wgVersion );
 182                 foreach ( $queue as $path => $mtime ) {
 183                         $json = file_get_contents( $path );
 184                         if ( $json === false ) {
 185                                 throw new Exception( "Unable to read $path, does it exist?" );
 186                         }
 187                         $info = json_decode( $json, /* $assoc = */ true );
 188                         if ( !is_array( $info ) ) {
 189                                 throw new Exception( "$path is not a valid JSON file." );
 190                         }
 191                         if ( !isset( $info['manifest_version'] ) ) {
 192                                 // For backwards-compatability, assume a version of 1
 193                                 $info['manifest_version'] = 1;
 194                         }
 195                         $version = $info['manifest_version'];
 196                         if ( $version < self::OLDEST_MANIFEST_VERSION || $version > self::MANIFEST_VERSION ) {
 197                                 throw new Exception( "$path: unsupported manifest_version: {$version}" );
 198                         }
 199                         $autoload = $this->processAutoLoader( dirname( $path ), $info );
 200                         // Set up the autoloader now so custom processors will work
 201                         $GLOBALS['wgAutoloadClasses'] += $autoload;
 202                         $autoloadClasses += $autoload;
 203                         // Check any constraints against MediaWiki core
 204                         $requires = $processor->getRequirements( $info );
 205                         if ( isset( $requires[self::MEDIAWIKI_CORE] )
 206                                 && !$coreVersionParser->check( $requires[self::MEDIAWIKI_CORE] )
 207                         ) {
 208                                 // Doesn't match, mark it as incompatible.
 209                                 $incompatible[] = "{$info['name']} is not compatible with the current "
 210                                         . "MediaWiki core (version {$wgVersion}), it requires: " . $requires[self::MEDIAWIKI_CORE]
 211                                         . '.';
 212                                 continue;
 213                         }
 214                         // Get extra paths for later inclusion
 215                         $autoloaderPaths = array_merge( $autoloaderPaths,
 216                                 $processor->getExtraAutoloaderPaths( dirname( $path ), $info ) );
 217                         // Compatible, read and extract info
 218                         $processor->extractInfo( $path, $info, $version );
 219                 }
 220                 if ( $incompatible ) {
 221                         if ( count( $incompatible ) === 1 ) {
 222                                 throw new Exception( $incompatible[0] );
 223                         } else {
 224                                 throw new Exception( implode( "\n", $incompatible ) );
 225                         }
 226                 }
 227                 $data = $processor->getExtractedInfo();
 228                 // Need to set this so we can += to it later
 229                 $data['globals']['wgAutoloadClasses'] = [];
 230                 $data['autoload'] = $autoloadClasses;
 231                 $data['autoloaderPaths'] = $autoloaderPaths;
 232                 return $data;
 233         }
 234
 235         protected function exportExtractedData( array $info ) {
 236                 foreach ( $info['globals'] as $key => $val ) {
 237                         // If a merge strategy is set, read it and remove it from the value
 238                         // so it doesn't accidentally end up getting set.
 239                         if ( is_array( $val ) && isset( $val[self::MERGE_STRATEGY] ) ) {
 240                                 $mergeStrategy = $val[self::MERGE_STRATEGY];
 241                                 unset( $val[self::MERGE_STRATEGY] );
 242                         } else {
 243                                 $mergeStrategy = 'array_merge';
 244                         }
 245
 246                         // Optimistic: If the global is not set, or is an empty array, replace it entirely.
 247                         // Will be O(1) performance.
 248                         if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
 249                                 $GLOBALS[$key] = $val;
 250                                 continue;
 251                         }
 252
 253                         if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
 254                                 // config setting that has already been overridden, don't set it
 255                                 continue;
 256                         }
 257
 258                         switch ( $mergeStrategy ) {
 259                                 case 'array_merge_recursive':
 260                                         $GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
 261                                         break;
 262                                 case 'array_plus_2d':
 263                                         $GLOBALS[$key] = wfArrayPlus2d( $GLOBALS[$key], $val );
 264                                         break;
 265                                 case 'array_plus':
 266                                         $GLOBALS[$key] += $val;
 267                                         break;
 268                                 case 'array_merge':
 269                                         $GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
 270                                         break;
 271                                 default:
 272                                         throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
 273                         }
 274                 }
 275
 276                 foreach ( $info['defines'] as $name => $val ) {
 277                         define( $name, $val );
 278                 }
 279                 foreach ( $info['autoloaderPaths'] as $path ) {
 280                         require_once $path;
 281                 }
 282                 foreach ( $info['callbacks'] as $cb ) {
 283                         call_user_func( $cb );
 284                 }
 285
 286                 $this->loaded += $info['credits'];
 287                 if ( $info['attributes'] ) {
 288                         if ( !$this->attributes ) {
 289                                 $this->attributes = $info['attributes'];
 290                         } else {
 291                                 $this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
 292                         }
 293                 }
 294         }
 295
 296         /**
 297          * Loads and processes the given JSON file without delay
 298          *
 299          * If some extensions are already queued, this will load
 300          * those as well.
 301          *
 302          * @param string $path Absolute path to the JSON file
 303          */
 304         public function load( $path ) {
 305                 $this->loadFromQueue(); // First clear the queue
 306                 $this->queue( $path );
 307                 $this->loadFromQueue();
 308         }
 309
 310         /**
 311          * Whether a thing has been loaded
 312          * @param string $name
 313          * @return bool
 314          */
 315         public function isLoaded( $name ) {
 316                 return isset( $this->loaded[$name] );
 317         }
 318
 319         /**
 320          * @param string $name
 321          * @return array
 322          */
 323         public function getAttribute( $name ) {
 324                 if ( isset( $this->attributes[$name] ) ) {
 325                         return $this->attributes[$name];
 326                 } else {
 327                         return [];
 328                 }
 329         }
 330
 331         /**
 332          * Get information about all things
 333          *
 334          * @return array
 335          */
 336         public function getAllThings() {
 337                 return $this->loaded;
 338         }
 339
 340         /**
 341          * Mark a thing as loaded
 342          *
 343          * @param string $name
 344          * @param array $credits
 345          */
 346         protected function markLoaded( $name, array $credits ) {
 347                 $this->loaded[$name] = $credits;
 348         }
 349
 350         /**
 351          * Register classes with the autoloader
 352          *
 353          * @param string $dir
 354          * @param array $info
 355          * @return array
 356          */
 357         protected function processAutoLoader( $dir, array $info ) {
 358                 if ( isset( $info['AutoloadClasses'] ) ) {
 359                         // Make paths absolute, relative to the JSON file
 360                         return array_map( function( $file ) use ( $dir ) {
 361                                 return "$dir/$file";
 362                         }, $info['AutoloadClasses'] );
 363                 } else {
 364                         return [];
 365                 }
 366         }
 367 }