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