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