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