includes/MediaWikiServices.php

   1 <?php
   2 namespace MediaWiki;
   3
   4 use Config;
   5 use ConfigFactory;
   6 use CryptRand;
   7 use EventRelayerGroup;
   8 use GenderCache;
   9 use GlobalVarConfig;
  10 use Hooks;
  11 use LBFactory;
  12 use LinkCache;
  13 use Liuggio\StatsdClient\Factory\StatsdDataFactory;
  14 use LoadBalancer;
  15 use MediaHandlerFactory;
  16 use MediaWiki\Linker\LinkRenderer;
  17 use MediaWiki\Linker\LinkRendererFactory;
  18 use MediaWiki\Services\SalvageableService;
  19 use MediaWiki\Services\ServiceContainer;
  20 use MediaWiki\Services\NoSuchServiceException;
  21 use MWException;
  22 use MimeAnalyzer;
  23 use ObjectCache;
  24 use ProxyLookup;
  25 use SearchEngine;
  26 use SearchEngineConfig;
  27 use SearchEngineFactory;
  28 use SiteLookup;
  29 use SiteStore;
  30 use WatchedItemStore;
  31 use WatchedItemQueryService;
  32 use SkinFactory;
  33 use TitleFormatter;
  34 use TitleParser;
  35 use VirtualRESTServiceClient;
  36 use MediaWiki\Interwiki\InterwikiLookup;
  37
  38 /**
  39  * Service locator for MediaWiki core services.
  40  *
  41  * This program is free software; you can redistribute it and/or modify
  42  * it under the terms of the GNU General Public License as published by
  43  * the Free Software Foundation; either version 2 of the License, or
  44  * (at your option) any later version.
  45  *
  46  * This program is distributed in the hope that it will be useful,
  47  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  48  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  49  * GNU General Public License for more details.
  50  *
  51  * You should have received a copy of the GNU General Public License along
  52  * with this program; if not, write to the Free Software Foundation, Inc.,
  53  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  54  * http://www.gnu.org/copyleft/gpl.html
  55  *
  56  * @file
  57  *
  58  * @since 1.27
  59  */
  60
  61 /**
  62  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  63  * Its implemented as a simple configurable DI container.
  64  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  65  * the network of service objects that defines MediaWiki's application logic.
  66  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  67  *
  68  * Services are defined in the "wiring" array passed to the constructor,
  69  * or by calling defineService().
  70  *
  71  * @see docs/injection.txt for an overview of using dependency injection in the
  72  *      MediaWiki code base.
  73  */
  74 class MediaWikiServices extends ServiceContainer {
  75
  76         /**
  77          * @var MediaWikiServices|null
  78          */
  79         private static $instance = null;
  80
  81         /**
  82          * Returns the global default instance of the top level service locator.
  83          *
  84          * @since 1.27
  85          *
  86          * The default instance is initialized using the service instantiator functions
  87          * defined in ServiceWiring.php.
  88          *
  89          * @note This should only be called by static functions! The instance returned here
  90          * should not be passed around! Objects that need access to a service should have
  91          * that service injected into the constructor, never a service locator!
  92          *
  93          * @return MediaWikiServices
  94          */
  95         public static function getInstance() {
  96                 if ( self::$instance === null ) {
  97                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
  98                         // but some information from the global scope has to be injected here,
  99                         // even if it's just a file name or database credentials to load
 100                         // configuration from.
 101                         $bootstrapConfig = new GlobalVarConfig();
 102                         self::$instance = self::newInstance( $bootstrapConfig, 'load' );
 103                 }
 104
 105                 return self::$instance;
 106         }
 107
 108         /**
 109          * Replaces the global MediaWikiServices instance.
 110          *
 111          * @since 1.28
 112          *
 113          * @note This is for use in PHPUnit tests only!
 114          *
 115          * @throws MWException if called outside of PHPUnit tests.
 116          *
 117          * @param MediaWikiServices $services The new MediaWikiServices object.
 118          *
 119          * @return MediaWikiServices The old MediaWikiServices object, so it can be restored later.
 120          */
 121         public static function forceGlobalInstance( MediaWikiServices $services ) {
 122                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 123                         throw new MWException( __METHOD__ . ' must not be used outside unit tests.' );
 124                 }
 125
 126                 $old = self::getInstance();
 127                 self::$instance = $services;
 128
 129                 return $old;
 130         }
 131
 132         /**
 133          * Creates a new instance of MediaWikiServices and sets it as the global default
 134          * instance. getInstance() will return a different MediaWikiServices object
 135          * after every call to resetGlobalInstance().
 136          *
 137          * @since 1.28
 138          *
 139          * @warning This should not be used during normal operation. It is intended for use
 140          * when the configuration has changed significantly since bootstrap time, e.g.
 141          * during the installation process or during testing.
 142          *
 143          * @warning Calling resetGlobalInstance() may leave the application in an inconsistent
 144          * state. Calling this is only safe under the ASSUMPTION that NO REFERENCE to
 145          * any of the services managed by MediaWikiServices exist. If any service objects
 146          * managed by the old MediaWikiServices instance remain in use, they may INTERFERE
 147          * with the operation of the services managed by the new MediaWikiServices.
 148          * Operating with a mix of services created by the old and the new
 149          * MediaWikiServices instance may lead to INCONSISTENCIES and even DATA LOSS!
 150          * Any class implementing LAZY LOADING is especially prone to this problem,
 151          * since instances would typically retain a reference to a storage layer service.
 152          *
 153          * @see forceGlobalInstance()
 154          * @see resetGlobalInstance()
 155          * @see resetBetweenTest()
 156          *
 157          * @param Config|null $bootstrapConfig The Config object to be registered as the
 158          *        'BootstrapConfig' service. This has to contain at least the information
 159          *        needed to set up the 'ConfigFactory' service. If not given, the bootstrap
 160          *        config of the old instance of MediaWikiServices will be re-used. If there
 161          *        was no previous instance, a new GlobalVarConfig object will be used to
 162          *        bootstrap the services.
 163          *
 164          * @param string $quick Set this to "quick" to allow expensive resources to be re-used.
 165          * See SalvageableService for details.
 166          *
 167          * @throws MWException If called after MW_SERVICE_BOOTSTRAP_COMPLETE has been defined in
 168          *         Setup.php (unless MW_PHPUNIT_TEST or MEDIAWIKI_INSTALL or RUN_MAINTENANCE_IF_MAIN
 169          *          is defined).
 170          */
 171         public static function resetGlobalInstance( Config $bootstrapConfig = null, $quick = '' ) {
 172                 if ( self::$instance === null ) {
 173                         // no global instance yet, nothing to reset
 174                         return;
 175                 }
 176
 177                 self::failIfResetNotAllowed( __METHOD__ );
 178
 179                 if ( $bootstrapConfig === null ) {
 180                         $bootstrapConfig = self::$instance->getBootstrapConfig();
 181                 }
 182
 183                 $oldInstance = self::$instance;
 184
 185                 self::$instance = self::newInstance( $bootstrapConfig );
 186                 self::$instance->importWiring( $oldInstance, [ 'BootstrapConfig' ] );
 187
 188                 if ( $quick === 'quick' ) {
 189                         self::$instance->salvage( $oldInstance );
 190                 } else {
 191                         $oldInstance->destroy();
 192                 }
 193
 194         }
 195
 196         /**
 197          * Salvages the state of any salvageable service instances in $other.
 198          *
 199          * @note $other will have been destroyed when salvage() returns.
 200          *
 201          * @param MediaWikiServices $other
 202          */
 203         private function salvage( self $other ) {
 204                 foreach ( $this->getServiceNames() as $name ) {
 205                         // The service could be new in the new instance and not registered in the
 206                         // other instance (e.g. an extension that was loaded after the instantiation of
 207                         // the other instance. Skip this service in this case. See T143974
 208                         try {
 209                                 $oldService = $other->peekService( $name );
 210                         } catch ( NoSuchServiceException $e ) {
 211                                 continue;
 212                         }
 213
 214                         if ( $oldService instanceof SalvageableService ) {
 215                                 /** @var SalvageableService $newService */
 216                                 $newService = $this->getService( $name );
 217                                 $newService->salvage( $oldService );
 218                         }
 219                 }
 220
 221                 $other->destroy();
 222         }
 223
 224         /**
 225          * Creates a new MediaWikiServices instance and initializes it according to the
 226          * given $bootstrapConfig. In particular, all wiring files defined in the
 227          * ServiceWiringFiles setting are loaded, and the MediaWikiServices hook is called.
 228          *
 229          * @param Config|null $bootstrapConfig The Config object to be registered as the
 230          *        'BootstrapConfig' service.
 231          *
 232          * @param string $loadWiring set this to 'load' to load the wiring files specified
 233          *        in the 'ServiceWiringFiles' setting in $bootstrapConfig.
 234          *
 235          * @return MediaWikiServices
 236          * @throws MWException
 237          * @throws \FatalError
 238          */
 239         private static function newInstance( Config $bootstrapConfig, $loadWiring = '' ) {
 240                 $instance = new self( $bootstrapConfig );
 241
 242                 // Load the default wiring from the specified files.
 243                 if ( $loadWiring === 'load' ) {
 244                         $wiringFiles = $bootstrapConfig->get( 'ServiceWiringFiles' );
 245                         $instance->loadWiringFiles( $wiringFiles );
 246                 }
 247
 248                 // Provide a traditional hook point to allow extensions to configure services.
 249                 Hooks::run( 'MediaWikiServices', [ $instance ] );
 250
 251                 return $instance;
 252         }
 253
 254         /**
 255          * Disables all storage layer services. After calling this, any attempt to access the
 256          * storage layer will result in an error. Use resetGlobalInstance() to restore normal
 257          * operation.
 258          *
 259          * @since 1.28
 260          *
 261          * @warning This is intended for extreme situations only and should never be used
 262          * while serving normal web requests. Legitimate use cases for this method include
 263          * the installation process. Test fixtures may also use this, if the fixture relies
 264          * on globalState.
 265          *
 266          * @see resetGlobalInstance()
 267          * @see resetChildProcessServices()
 268          */
 269         public static function disableStorageBackend() {
 270                 // TODO: also disable some Caches, JobQueues, etc
 271                 $destroy = [ 'DBLoadBalancer', 'DBLoadBalancerFactory' ];
 272                 $services = self::getInstance();
 273
 274                 foreach ( $destroy as $name ) {
 275                         $services->disableService( $name );
 276                 }
 277
 278                 ObjectCache::clear();
 279         }
 280
 281         /**
 282          * Resets any services that may have become stale after a child process
 283          * returns from after pcntl_fork(). It's also safe, but generally unnecessary,
 284          * to call this method from the parent process.
 285          *
 286          * @since 1.28
 287          *
 288          * @note This is intended for use in the context of process forking only!
 289          *
 290          * @see resetGlobalInstance()
 291          * @see disableStorageBackend()
 292          */
 293         public static function resetChildProcessServices() {
 294                 // NOTE: for now, just reset everything. Since we don't know the interdependencies
 295                 // between services, we can't do this more selectively at this time.
 296                 self::resetGlobalInstance();
 297
 298                 // Child, reseed because there is no bug in PHP:
 299                 // http://bugs.php.net/bug.php?id=42465
 300                 mt_srand( getmypid() );
 301         }
 302
 303         /**
 304          * Resets the given service for testing purposes.
 305          *
 306          * @since 1.28
 307          *
 308          * @warning This is generally unsafe! Other services may still retain references
 309          * to the stale service instance, leading to failures and inconsistencies. Subclasses
 310          * may use this method to reset specific services under specific instances, but
 311          * it should not be exposed to application logic.
 312          *
 313          * @note With proper dependency injection used throughout the codebase, this method
 314          * should not be needed. It is provided to allow tests that pollute global service
 315          * instances to clean up.
 316          *
 317          * @param string $name
 318          * @param bool $destroy Whether the service instance should be destroyed if it exists.
 319          *        When set to false, any existing service instance will effectively be detached
 320          *        from the container.
 321          *
 322          * @throws MWException if called outside of PHPUnit tests.
 323          */
 324         public function resetServiceForTesting( $name, $destroy = true ) {
 325                 if ( !defined( 'MW_PHPUNIT_TEST' ) && !defined( 'MW_PARSER_TEST' ) ) {
 326                         throw new MWException( 'resetServiceForTesting() must not be used outside unit tests.' );
 327                 }
 328
 329                 $this->resetService( $name, $destroy );
 330         }
 331
 332         /**
 333          * Convenience method that throws an exception unless it is called during a phase in which
 334          * resetting of global services is allowed. In general, services should not be reset
 335          * individually, since that may introduce inconsistencies.
 336          *
 337          * @since 1.28
 338          *
 339          * This method will throw an exception if:
 340          *
 341          * - self::$resetInProgress is false (to allow all services to be reset together
 342          *   via resetGlobalInstance)
 343          * - and MEDIAWIKI_INSTALL is not defined (to allow services to be reset during installation)
 344          * - and MW_PHPUNIT_TEST is not defined (to allow services to be reset during testing)
 345          *
 346          * This method is intended to be used to safeguard against accidentally resetting
 347          * global service instances that are not yet managed by MediaWikiServices. It is
 348          * defined here in the MediaWikiServices services class to have a central place
 349          * for managing service bootstrapping and resetting.
 350          *
 351          * @param string $method the name of the caller method, as given by __METHOD__.
 352          *
 353          * @throws MWException if called outside bootstrap mode.
 354          *
 355          * @see resetGlobalInstance()
 356          * @see forceGlobalInstance()
 357          * @see disableStorageBackend()
 358          */
 359         public static function failIfResetNotAllowed( $method ) {
 360                 if ( !defined( 'MW_PHPUNIT_TEST' )
 361                         && !defined( 'MW_PARSER_TEST' )
 362                         && !defined( 'MEDIAWIKI_INSTALL' )
 363                         && !defined( 'RUN_MAINTENANCE_IF_MAIN' )
 364                         && defined( 'MW_SERVICE_BOOTSTRAP_COMPLETE' )
 365                 ) {
 366                         throw new MWException( $method . ' may only be called during bootstrapping and unit tests!' );
 367                 }
 368         }
 369
 370         /**
 371          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
 372          *        This has to contain at least the information needed to set up the 'ConfigFactory'
 373          *        service.
 374          */
 375         public function __construct( Config $config ) {
 376                 parent::__construct();
 377
 378                 // Register the given Config object as the bootstrap config service.
 379                 $this->defineService( 'BootstrapConfig', function() use ( $config ) {
 380                         return $config;
 381                 } );
 382         }
 383
 384         // CONVENIENCE GETTERS ////////////////////////////////////////////////////
 385
 386         /**
 387          * Returns the Config object containing the bootstrap configuration.
 388          * Bootstrap configuration would typically include database credentials
 389          * and other information that may be needed before the ConfigFactory
 390          * service can be instantiated.
 391          *
 392          * @note This should only be used during bootstrapping, in particular
 393          * when creating the MainConfig service. Application logic should
 394          * use getMainConfig() to get a Config instances.
 395          *
 396          * @since 1.27
 397          * @return Config
 398          */
 399         public function getBootstrapConfig() {
 400                 return $this->getService( 'BootstrapConfig' );
 401         }
 402
 403         /**
 404          * @since 1.27
 405          * @return ConfigFactory
 406          */
 407         public function getConfigFactory() {
 408                 return $this->getService( 'ConfigFactory' );
 409         }
 410
 411         /**
 412          * Returns the Config object that provides configuration for MediaWiki core.
 413          * This may or may not be the same object that is returned by getBootstrapConfig().
 414          *
 415          * @since 1.27
 416          * @return Config
 417          */
 418         public function getMainConfig() {
 419                 return $this->getService( 'MainConfig' );
 420         }
 421
 422         /**
 423          * @since 1.27
 424          * @return SiteLookup
 425          */
 426         public function getSiteLookup() {
 427                 return $this->getService( 'SiteLookup' );
 428         }
 429
 430         /**
 431          * @since 1.27
 432          * @return SiteStore
 433          */
 434         public function getSiteStore() {
 435                 return $this->getService( 'SiteStore' );
 436         }
 437
 438         /**
 439          * @since 1.28
 440          * @return InterwikiLookup
 441          */
 442         public function getInterwikiLookup() {
 443                 return $this->getService( 'InterwikiLookup' );
 444         }
 445
 446         /**
 447          * @since 1.27
 448          * @return StatsdDataFactory
 449          */
 450         public function getStatsdDataFactory() {
 451                 return $this->getService( 'StatsdDataFactory' );
 452         }
 453
 454         /**
 455          * @since 1.27
 456          * @return EventRelayerGroup
 457          */
 458         public function getEventRelayerGroup() {
 459                 return $this->getService( 'EventRelayerGroup' );
 460         }
 461
 462         /**
 463          * @since 1.27
 464          * @return SearchEngine
 465          */
 466         public function newSearchEngine() {
 467                 // New engine object every time, since they keep state
 468                 return $this->getService( 'SearchEngineFactory' )->create();
 469         }
 470
 471         /**
 472          * @since 1.27
 473          * @return SearchEngineFactory
 474          */
 475         public function getSearchEngineFactory() {
 476                 return $this->getService( 'SearchEngineFactory' );
 477         }
 478
 479         /**
 480          * @since 1.27
 481          * @return SearchEngineConfig
 482          */
 483         public function getSearchEngineConfig() {
 484                 return $this->getService( 'SearchEngineConfig' );
 485         }
 486
 487         /**
 488          * @since 1.27
 489          * @return SkinFactory
 490          */
 491         public function getSkinFactory() {
 492                 return $this->getService( 'SkinFactory' );
 493         }
 494
 495         /**
 496          * @since 1.28
 497          * @return LBFactory
 498          */
 499         public function getDBLoadBalancerFactory() {
 500                 return $this->getService( 'DBLoadBalancerFactory' );
 501         }
 502
 503         /**
 504          * @since 1.28
 505          * @return LoadBalancer The main DB load balancer for the local wiki.
 506          */
 507         public function getDBLoadBalancer() {
 508                 return $this->getService( 'DBLoadBalancer' );
 509         }
 510
 511         /**
 512          * @since 1.28
 513          * @return WatchedItemStore
 514          */
 515         public function getWatchedItemStore() {
 516                 return $this->getService( 'WatchedItemStore' );
 517         }
 518
 519         /**
 520          * @since 1.28
 521          * @return WatchedItemQueryService
 522          */
 523         public function getWatchedItemQueryService() {
 524                 return $this->getService( 'WatchedItemQueryService' );
 525         }
 526
 527         /**
 528          * @since 1.28
 529          * @return CryptRand
 530          */
 531         public function getCryptRand() {
 532                 return $this->getService( 'CryptRand' );
 533         }
 534
 535         /**
 536          * @since 1.28
 537          * @return MediaHandlerFactory
 538          */
 539         public function getMediaHandlerFactory() {
 540                 return $this->getService( 'MediaHandlerFactory' );
 541         }
 542
 543         /**
 544          * @since 1.28
 545          * @return MimeAnalyzer
 546          */
 547         public function getMimeAnalyzer() {
 548                 return $this->getService( 'MimeAnalyzer' );
 549         }
 550
 551         /**
 552          * @since 1.28
 553          * @return ProxyLookup
 554          */
 555         public function getProxyLookup() {
 556                 return $this->getService( 'ProxyLookup' );
 557         }
 558
 559         /**
 560          * @since 1.28
 561          * @return GenderCache
 562          */
 563         public function getGenderCache() {
 564                 return $this->getService( 'GenderCache' );
 565         }
 566
 567         /**
 568          * @since 1.28
 569          * @return LinkCache
 570          */
 571         public function getLinkCache() {
 572                 return $this->getService( 'LinkCache' );
 573         }
 574
 575         /**
 576          * @since 1.28
 577          * @return LinkRendererFactory
 578          */
 579         public function getLinkRendererFactory() {
 580                 return $this->getService( 'LinkRendererFactory' );
 581         }
 582
 583         /**
 584          * LinkRenderer instance that can be used
 585          * if no custom options are needed
 586          *
 587          * @since 1.28
 588          * @return LinkRenderer
 589          */
 590         public function getLinkRenderer() {
 591                 return $this->getService( 'LinkRenderer' );
 592         }
 593
 594         /**
 595          * @since 1.28
 596          * @return TitleFormatter
 597          */
 598         public function getTitleFormatter() {
 599                 return $this->getService( 'TitleFormatter' );
 600         }
 601
 602         /**
 603          * @since 1.28
 604          * @return TitleParser
 605          */
 606         public function getTitleParser() {
 607                 return $this->getService( 'TitleParser' );
 608         }
 609
 610         /**
 611          * @since 1.28
 612          * @return \BagOStuff
 613          */
 614         public function getMainObjectStash() {
 615                 return $this->getService( 'MainObjectStash' );
 616         }
 617
 618         /**
 619          * @since 1.28
 620          * @return \WANObjectCache
 621          */
 622         public function getMainWANObjectCache() {
 623                 return $this->getService( 'MainWANObjectCache' );
 624         }
 625
 626         /**
 627          * @since 1.28
 628          * @return \BagOStuff
 629          */
 630         public function getLocalServerObjectCache() {
 631                 return $this->getService( 'LocalServerObjectCache' );
 632         }
 633
 634         /**
 635          * @since 1.28
 636          * @return VirtualRESTServiceClient
 637          */
 638         public function getVirtualRESTServiceClient() {
 639                 return $this->getService( 'VirtualRESTServiceClient' );
 640         }
 641
 642         ///////////////////////////////////////////////////////////////////////////
 643         // NOTE: When adding a service getter here, don't forget to add a test
 644         // case for it in MediaWikiServicesTest::provideGetters() and in
 645         // MediaWikiServicesTest::provideGetService()!
 646         ///////////////////////////////////////////////////////////////////////////
 647
 648 }