includes/MediaWikiServices.php

   1 <?php
   2 namespace MediaWiki;
   3
   4 use Config;
   5 use ConfigFactory;
   6 use CryptHKDF;
   7 use CryptRand;
   8 use EventRelayerGroup;
   9 use GenderCache;
  10 use GlobalVarConfig;
  11 use Hooks;
  12 use IBufferingStatsdDataFactory;
  13 use MediaWiki\Shell\CommandFactory;
  14 use MediaWiki\Storage\BlobStore;
  15 use MediaWiki\Storage\RevisionStore;
  16 use Wikimedia\Rdbms\LBFactory;
  17 use LinkCache;
  18 use Wikimedia\Rdbms\LoadBalancer;
  19 use MediaHandlerFactory;
  20 use MediaWiki\Linker\LinkRenderer;
  21 use MediaWiki\Linker\LinkRendererFactory;
  22 use MediaWiki\Services\SalvageableService;
  23 use MediaWiki\Services\ServiceContainer;
  24 use MediaWiki\Services\NoSuchServiceException;
  25 use MWException;
  26 use MimeAnalyzer;
  27 use ObjectCache;
  28 use Parser;
  29 use ParserCache;
  30 use ProxyLookup;
  31 use SearchEngine;
  32 use SearchEngineConfig;
  33 use SearchEngineFactory;
  34 use SiteLookup;
  35 use SiteStore;
  36 use WatchedItemStoreInterface;
  37 use WatchedItemQueryService;
  38 use SkinFactory;
  39 use TitleFormatter;
  40 use TitleParser;
  41 use VirtualRESTServiceClient;
  42 use MediaWiki\Interwiki\InterwikiLookup;
  43
  44 /**
  45  * Service locator for MediaWiki core services.
  46  *
  47  * This program is free software; you can redistribute it and/or modify
  48  * it under the terms of the GNU General Public License as published by
  49  * the Free Software Foundation; either version 2 of the License, or
  50  * (at your option) any later version.
  51  *
  52  * This program is distributed in the hope that it will be useful,
  53  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  54  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  55  * GNU General Public License for more details.
  56  *
  57  * You should have received a copy of the GNU General Public License along
  58  * with this program; if not, write to the Free Software Foundation, Inc.,
  59  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  60  * http://www.gnu.org/copyleft/gpl.html
  61  *
  62  * @file
  63  *
  64  * @since 1.27
  65  */
  66
  67 /**
  68  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  69  * Its implemented as a simple configurable DI container.
  70  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  71  * the network of service objects that defines MediaWiki's application logic.
  72  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  73  *
  74  * Services are defined in the "wiring" array passed to the constructor,
  75  * or by calling defineService().
  76  *
  77  * @see docs/injection.txt for an overview of using dependency injection in the
  78  *      MediaWiki code base.
  79  */
  80 class MediaWikiServices extends ServiceContainer {
  81
  82         /**
  83          * @var MediaWikiServices|null
  84          */
  85         private static $instance = null;
  86
  87         /**
  88          * Returns the global default instance of the top level service locator.
  89          *
  90          * @since 1.27
  91          *
  92          * The default instance is initialized using the service instantiator functions
  93          * defined in ServiceWiring.php.
  94          *
  95          * @note This should only be called by static functions! The instance returned here
  96          * should not be passed around! Objects that need access to a service should have
  97          * that service injected into the constructor, never a service locator!
  98          *
  99          * @return MediaWikiServices
 100          */
 101         public static function getInstance() {
 102                 if ( self::$instance === null ) {
 103                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
 104                         // but some information from the global scope has to be injected here,
 105                         // even if it's just a file name or database credentials to load
 106                         // configuration from.
 107                         $bootstrapConfig = new GlobalVarConfig();
 108                         self::$instance = self::newInstance( $bootstrapConfig, 'load' );
 109                 }
 110
 111                 return self::$instance;
 112         }
 113
 114         /**
 115          * Replaces the global MediaWikiServices instance.
 116          *
 117          * @since 1.28
 118          *
 119          * @note This is for use in PHPUnit tests only!
 120          *
 121          * @throws MWException if called outside of PHPUnit tests.
 122          *
 123          * @param MediaWikiServices $services The new MediaWikiServices object.
 124          *
 125          * @return MediaWikiServices The old MediaWikiServices object, so it can be restored later.
 126          */
 127         public static function forceGlobalInstance( MediaWikiServices $services ) {
 128                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 129                         throw new MWException( __METHOD__ . ' must not be used outside unit tests.' );
 130                 }
 131
 132                 $old = self::getInstance();
 133                 self::$instance = $services;
 134
 135                 return $old;
 136         }
 137
 138         /**
 139          * Creates a new instance of MediaWikiServices and sets it as the global default
 140          * instance. getInstance() will return a different MediaWikiServices object
 141          * after every call to resetGlobalInstance().
 142          *
 143          * @since 1.28
 144          *
 145          * @warning This should not be used during normal operation. It is intended for use
 146          * when the configuration has changed significantly since bootstrap time, e.g.
 147          * during the installation process or during testing.
 148          *
 149          * @warning Calling resetGlobalInstance() may leave the application in an inconsistent
 150          * state. Calling this is only safe under the ASSUMPTION that NO REFERENCE to
 151          * any of the services managed by MediaWikiServices exist. If any service objects
 152          * managed by the old MediaWikiServices instance remain in use, they may INTERFERE
 153          * with the operation of the services managed by the new MediaWikiServices.
 154          * Operating with a mix of services created by the old and the new
 155          * MediaWikiServices instance may lead to INCONSISTENCIES and even DATA LOSS!
 156          * Any class implementing LAZY LOADING is especially prone to this problem,
 157          * since instances would typically retain a reference to a storage layer service.
 158          *
 159          * @see forceGlobalInstance()
 160          * @see resetGlobalInstance()
 161          * @see resetBetweenTest()
 162          *
 163          * @param Config|null $bootstrapConfig The Config object to be registered as the
 164          *        'BootstrapConfig' service. This has to contain at least the information
 165          *        needed to set up the 'ConfigFactory' service. If not given, the bootstrap
 166          *        config of the old instance of MediaWikiServices will be re-used. If there
 167          *        was no previous instance, a new GlobalVarConfig object will be used to
 168          *        bootstrap the services.
 169          *
 170          * @param string $quick Set this to "quick" to allow expensive resources to be re-used.
 171          * See SalvageableService for details.
 172          *
 173          * @throws MWException If called after MW_SERVICE_BOOTSTRAP_COMPLETE has been defined in
 174          *         Setup.php (unless MW_PHPUNIT_TEST or MEDIAWIKI_INSTALL or RUN_MAINTENANCE_IF_MAIN
 175          *          is defined).
 176          */
 177         public static function resetGlobalInstance( Config $bootstrapConfig = null, $quick = '' ) {
 178                 if ( self::$instance === null ) {
 179                         // no global instance yet, nothing to reset
 180                         return;
 181                 }
 182
 183                 self::failIfResetNotAllowed( __METHOD__ );
 184
 185                 if ( $bootstrapConfig === null ) {
 186                         $bootstrapConfig = self::$instance->getBootstrapConfig();
 187                 }
 188
 189                 $oldInstance = self::$instance;
 190
 191                 self::$instance = self::newInstance( $bootstrapConfig, 'load' );
 192                 self::$instance->importWiring( $oldInstance, [ 'BootstrapConfig' ] );
 193
 194                 if ( $quick === 'quick' ) {
 195                         self::$instance->salvage( $oldInstance );
 196                 } else {
 197                         $oldInstance->destroy();
 198                 }
 199         }
 200
 201         /**
 202          * Salvages the state of any salvageable service instances in $other.
 203          *
 204          * @note $other will have been destroyed when salvage() returns.
 205          *
 206          * @param MediaWikiServices $other
 207          */
 208         private function salvage( self $other ) {
 209                 foreach ( $this->getServiceNames() as $name ) {
 210                         // The service could be new in the new instance and not registered in the
 211                         // other instance (e.g. an extension that was loaded after the instantiation of
 212                         // the other instance. Skip this service in this case. See T143974
 213                         try {
 214                                 $oldService = $other->peekService( $name );
 215                         } catch ( NoSuchServiceException $e ) {
 216                                 continue;
 217                         }
 218
 219                         if ( $oldService instanceof SalvageableService ) {
 220                                 /** @var SalvageableService $newService */
 221                                 $newService = $this->getService( $name );
 222                                 $newService->salvage( $oldService );
 223                         }
 224                 }
 225
 226                 $other->destroy();
 227         }
 228
 229         /**
 230          * Creates a new MediaWikiServices instance and initializes it according to the
 231          * given $bootstrapConfig. In particular, all wiring files defined in the
 232          * ServiceWiringFiles setting are loaded, and the MediaWikiServices hook is called.
 233          *
 234          * @param Config|null $bootstrapConfig The Config object to be registered as the
 235          *        'BootstrapConfig' service.
 236          *
 237          * @param string $loadWiring set this to 'load' to load the wiring files specified
 238          *        in the 'ServiceWiringFiles' setting in $bootstrapConfig.
 239          *
 240          * @return MediaWikiServices
 241          * @throws MWException
 242          * @throws \FatalError
 243          */
 244         private static function newInstance( Config $bootstrapConfig, $loadWiring = '' ) {
 245                 $instance = new self( $bootstrapConfig );
 246
 247                 // Load the default wiring from the specified files.
 248                 if ( $loadWiring === 'load' ) {
 249                         $wiringFiles = $bootstrapConfig->get( 'ServiceWiringFiles' );
 250                         $instance->loadWiringFiles( $wiringFiles );
 251                 }
 252
 253                 // Provide a traditional hook point to allow extensions to configure services.
 254                 Hooks::run( 'MediaWikiServices', [ $instance ] );
 255
 256                 return $instance;
 257         }
 258
 259         /**
 260          * Disables all storage layer services. After calling this, any attempt to access the
 261          * storage layer will result in an error. Use resetGlobalInstance() to restore normal
 262          * operation.
 263          *
 264          * @since 1.28
 265          *
 266          * @warning This is intended for extreme situations only and should never be used
 267          * while serving normal web requests. Legitimate use cases for this method include
 268          * the installation process. Test fixtures may also use this, if the fixture relies
 269          * on globalState.
 270          *
 271          * @see resetGlobalInstance()
 272          * @see resetChildProcessServices()
 273          */
 274         public static function disableStorageBackend() {
 275                 // TODO: also disable some Caches, JobQueues, etc
 276                 $destroy = [ 'DBLoadBalancer', 'DBLoadBalancerFactory' ];
 277                 $services = self::getInstance();
 278
 279                 foreach ( $destroy as $name ) {
 280                         $services->disableService( $name );
 281                 }
 282
 283                 ObjectCache::clear();
 284         }
 285
 286         /**
 287          * Resets any services that may have become stale after a child process
 288          * returns from after pcntl_fork(). It's also safe, but generally unnecessary,
 289          * to call this method from the parent process.
 290          *
 291          * @since 1.28
 292          *
 293          * @note This is intended for use in the context of process forking only!
 294          *
 295          * @see resetGlobalInstance()
 296          * @see disableStorageBackend()
 297          */
 298         public static function resetChildProcessServices() {
 299                 // NOTE: for now, just reset everything. Since we don't know the interdependencies
 300                 // between services, we can't do this more selectively at this time.
 301                 self::resetGlobalInstance();
 302
 303                 // Child, reseed because there is no bug in PHP:
 304                 // https://bugs.php.net/bug.php?id=42465
 305                 mt_srand( getmypid() );
 306         }
 307
 308         /**
 309          * Resets the given service for testing purposes.
 310          *
 311          * @since 1.28
 312          *
 313          * @warning This is generally unsafe! Other services may still retain references
 314          * to the stale service instance, leading to failures and inconsistencies. Subclasses
 315          * may use this method to reset specific services under specific instances, but
 316          * it should not be exposed to application logic.
 317          *
 318          * @note With proper dependency injection used throughout the codebase, this method
 319          * should not be needed. It is provided to allow tests that pollute global service
 320          * instances to clean up.
 321          *
 322          * @param string $name
 323          * @param bool $destroy Whether the service instance should be destroyed if it exists.
 324          *        When set to false, any existing service instance will effectively be detached
 325          *        from the container.
 326          *
 327          * @throws MWException if called outside of PHPUnit tests.
 328          */
 329         public function resetServiceForTesting( $name, $destroy = true ) {
 330                 if ( !defined( 'MW_PHPUNIT_TEST' ) && !defined( 'MW_PARSER_TEST' ) ) {
 331                         throw new MWException( 'resetServiceForTesting() must not be used outside unit tests.' );
 332                 }
 333
 334                 $this->resetService( $name, $destroy );
 335         }
 336
 337         /**
 338          * Convenience method that throws an exception unless it is called during a phase in which
 339          * resetting of global services is allowed. In general, services should not be reset
 340          * individually, since that may introduce inconsistencies.
 341          *
 342          * @since 1.28
 343          *
 344          * This method will throw an exception if:
 345          *
 346          * - self::$resetInProgress is false (to allow all services to be reset together
 347          *   via resetGlobalInstance)
 348          * - and MEDIAWIKI_INSTALL is not defined (to allow services to be reset during installation)
 349          * - and MW_PHPUNIT_TEST is not defined (to allow services to be reset during testing)
 350          *
 351          * This method is intended to be used to safeguard against accidentally resetting
 352          * global service instances that are not yet managed by MediaWikiServices. It is
 353          * defined here in the MediaWikiServices services class to have a central place
 354          * for managing service bootstrapping and resetting.
 355          *
 356          * @param string $method the name of the caller method, as given by __METHOD__.
 357          *
 358          * @throws MWException if called outside bootstrap mode.
 359          *
 360          * @see resetGlobalInstance()
 361          * @see forceGlobalInstance()
 362          * @see disableStorageBackend()
 363          */
 364         public static function failIfResetNotAllowed( $method ) {
 365                 if ( !defined( 'MW_PHPUNIT_TEST' )
 366                         && !defined( 'MW_PARSER_TEST' )
 367                         && !defined( 'MEDIAWIKI_INSTALL' )
 368                         && !defined( 'RUN_MAINTENANCE_IF_MAIN' )
 369                         && defined( 'MW_SERVICE_BOOTSTRAP_COMPLETE' )
 370                 ) {
 371                         throw new MWException( $method . ' may only be called during bootstrapping and unit tests!' );
 372                 }
 373         }
 374
 375         /**
 376          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
 377          *        This has to contain at least the information needed to set up the 'ConfigFactory'
 378          *        service.
 379          */
 380         public function __construct( Config $config ) {
 381                 parent::__construct();
 382
 383                 // Register the given Config object as the bootstrap config service.
 384                 $this->defineService( 'BootstrapConfig', function () use ( $config ) {
 385                         return $config;
 386                 } );
 387         }
 388
 389         // CONVENIENCE GETTERS ////////////////////////////////////////////////////
 390
 391         /**
 392          * Returns the Config object containing the bootstrap configuration.
 393          * Bootstrap configuration would typically include database credentials
 394          * and other information that may be needed before the ConfigFactory
 395          * service can be instantiated.
 396          *
 397          * @note This should only be used during bootstrapping, in particular
 398          * when creating the MainConfig service. Application logic should
 399          * use getMainConfig() to get a Config instances.
 400          *
 401          * @since 1.27
 402          * @return Config
 403          */
 404         public function getBootstrapConfig() {
 405                 return $this->getService( 'BootstrapConfig' );
 406         }
 407
 408         /**
 409          * @since 1.27
 410          * @return ConfigFactory
 411          */
 412         public function getConfigFactory() {
 413                 return $this->getService( 'ConfigFactory' );
 414         }
 415
 416         /**
 417          * Returns the Config object that provides configuration for MediaWiki core.
 418          * This may or may not be the same object that is returned by getBootstrapConfig().
 419          *
 420          * @since 1.27
 421          * @return Config
 422          */
 423         public function getMainConfig() {
 424                 return $this->getService( 'MainConfig' );
 425         }
 426
 427         /**
 428          * @since 1.27
 429          * @return SiteLookup
 430          */
 431         public function getSiteLookup() {
 432                 return $this->getService( 'SiteLookup' );
 433         }
 434
 435         /**
 436          * @since 1.27
 437          * @return SiteStore
 438          */
 439         public function getSiteStore() {
 440                 return $this->getService( 'SiteStore' );
 441         }
 442
 443         /**
 444          * @since 1.28
 445          * @return InterwikiLookup
 446          */
 447         public function getInterwikiLookup() {
 448                 return $this->getService( 'InterwikiLookup' );
 449         }
 450
 451         /**
 452          * @since 1.27
 453          * @return IBufferingStatsdDataFactory
 454          */
 455         public function getStatsdDataFactory() {
 456                 return $this->getService( 'StatsdDataFactory' );
 457         }
 458
 459         /**
 460          * @since 1.27
 461          * @return EventRelayerGroup
 462          */
 463         public function getEventRelayerGroup() {
 464                 return $this->getService( 'EventRelayerGroup' );
 465         }
 466
 467         /**
 468          * @since 1.27
 469          * @return SearchEngine
 470          */
 471         public function newSearchEngine() {
 472                 // New engine object every time, since they keep state
 473                 return $this->getService( 'SearchEngineFactory' )->create();
 474         }
 475
 476         /**
 477          * @since 1.27
 478          * @return SearchEngineFactory
 479          */
 480         public function getSearchEngineFactory() {
 481                 return $this->getService( 'SearchEngineFactory' );
 482         }
 483
 484         /**
 485          * @since 1.27
 486          * @return SearchEngineConfig
 487          */
 488         public function getSearchEngineConfig() {
 489                 return $this->getService( 'SearchEngineConfig' );
 490         }
 491
 492         /**
 493          * @since 1.27
 494          * @return SkinFactory
 495          */
 496         public function getSkinFactory() {
 497                 return $this->getService( 'SkinFactory' );
 498         }
 499
 500         /**
 501          * @since 1.28
 502          * @return LBFactory
 503          */
 504         public function getDBLoadBalancerFactory() {
 505                 return $this->getService( 'DBLoadBalancerFactory' );
 506         }
 507
 508         /**
 509          * @since 1.28
 510          * @return LoadBalancer The main DB load balancer for the local wiki.
 511          */
 512         public function getDBLoadBalancer() {
 513                 return $this->getService( 'DBLoadBalancer' );
 514         }
 515
 516         /**
 517          * @since 1.28
 518          * @return WatchedItemStoreInterface
 519          */
 520         public function getWatchedItemStore() {
 521                 return $this->getService( 'WatchedItemStore' );
 522         }
 523
 524         /**
 525          * @since 1.28
 526          * @return WatchedItemQueryService
 527          */
 528         public function getWatchedItemQueryService() {
 529                 return $this->getService( 'WatchedItemQueryService' );
 530         }
 531
 532         /**
 533          * @since 1.28
 534          * @return CryptRand
 535          */
 536         public function getCryptRand() {
 537                 return $this->getService( 'CryptRand' );
 538         }
 539
 540         /**
 541          * @since 1.28
 542          * @return CryptHKDF
 543          */
 544         public function getCryptHKDF() {
 545                 return $this->getService( 'CryptHKDF' );
 546         }
 547
 548         /**
 549          * @since 1.28
 550          * @return MediaHandlerFactory
 551          */
 552         public function getMediaHandlerFactory() {
 553                 return $this->getService( 'MediaHandlerFactory' );
 554         }
 555
 556         /**
 557          * @since 1.28
 558          * @return MimeAnalyzer
 559          */
 560         public function getMimeAnalyzer() {
 561                 return $this->getService( 'MimeAnalyzer' );
 562         }
 563
 564         /**
 565          * @since 1.28
 566          * @return ProxyLookup
 567          */
 568         public function getProxyLookup() {
 569                 return $this->getService( 'ProxyLookup' );
 570         }
 571
 572         /**
 573          * @since 1.29
 574          * @return Parser
 575          */
 576         public function getParser() {
 577                 return $this->getService( 'Parser' );
 578         }
 579
 580         /**
 581          * @since 1.30
 582          * @return ParserCache
 583          */
 584         public function getParserCache() {
 585                 return $this->getService( 'ParserCache' );
 586         }
 587
 588         /**
 589          * @since 1.28
 590          * @return GenderCache
 591          */
 592         public function getGenderCache() {
 593                 return $this->getService( 'GenderCache' );
 594         }
 595
 596         /**
 597          * @since 1.28
 598          * @return LinkCache
 599          */
 600         public function getLinkCache() {
 601                 return $this->getService( 'LinkCache' );
 602         }
 603
 604         /**
 605          * @since 1.28
 606          * @return LinkRendererFactory
 607          */
 608         public function getLinkRendererFactory() {
 609                 return $this->getService( 'LinkRendererFactory' );
 610         }
 611
 612         /**
 613          * LinkRenderer instance that can be used
 614          * if no custom options are needed
 615          *
 616          * @since 1.28
 617          * @return LinkRenderer
 618          */
 619         public function getLinkRenderer() {
 620                 return $this->getService( 'LinkRenderer' );
 621         }
 622
 623         /**
 624          * @since 1.28
 625          * @return TitleFormatter
 626          */
 627         public function getTitleFormatter() {
 628                 return $this->getService( 'TitleFormatter' );
 629         }
 630
 631         /**
 632          * @since 1.28
 633          * @return TitleParser
 634          */
 635         public function getTitleParser() {
 636                 return $this->getService( 'TitleParser' );
 637         }
 638
 639         /**
 640          * @since 1.28
 641          * @return \BagOStuff
 642          */
 643         public function getMainObjectStash() {
 644                 return $this->getService( 'MainObjectStash' );
 645         }
 646
 647         /**
 648          * @since 1.28
 649          * @return \WANObjectCache
 650          */
 651         public function getMainWANObjectCache() {
 652                 return $this->getService( 'MainWANObjectCache' );
 653         }
 654
 655         /**
 656          * @since 1.28
 657          * @return \BagOStuff
 658          */
 659         public function getLocalServerObjectCache() {
 660                 return $this->getService( 'LocalServerObjectCache' );
 661         }
 662
 663         /**
 664          * @since 1.28
 665          * @return VirtualRESTServiceClient
 666          */
 667         public function getVirtualRESTServiceClient() {
 668                 return $this->getService( 'VirtualRESTServiceClient' );
 669         }
 670
 671         /**
 672          * @since 1.29
 673          * @return \ConfiguredReadOnlyMode
 674          */
 675         public function getConfiguredReadOnlyMode() {
 676                 return $this->getService( 'ConfiguredReadOnlyMode' );
 677         }
 678
 679         /**
 680          * @since 1.29
 681          * @return \ReadOnlyMode
 682          */
 683         public function getReadOnlyMode() {
 684                 return $this->getService( 'ReadOnlyMode' );
 685         }
 686
 687         /**
 688          * @since 1.30
 689          * @return CommandFactory
 690          */
 691         public function getShellCommandFactory() {
 692                 return $this->getService( 'ShellCommandFactory' );
 693         }
 694
 695         /**
 696          * @since 1.31
 697          * @return \ExternalStoreFactory
 698          */
 699         public function getExternalStoreFactory() {
 700                 return $this->getService( 'ExternalStoreFactory' );
 701         }
 702
 703         /**
 704          * @since 1.31
 705          * @return BlobStore
 706          */
 707         public function getBlobStore() {
 708                 return $this->getService( 'BlobStore' );
 709         }
 710
 711         /**
 712          * @since 1.31
 713          * @return RevisionStore
 714          */
 715         public function getRevisionStore() {
 716                 return $this->getService( 'RevisionStore' );
 717         }
 718
 719         ///////////////////////////////////////////////////////////////////////////
 720         // NOTE: When adding a service getter here, don't forget to add a test
 721         // case for it in MediaWikiServicesTest::provideGetters() and in
 722         // MediaWikiServicesTest::provideGetService()!
 723         ///////////////////////////////////////////////////////////////////////////
 724
 725 }