X-Git-Url: https://scripts.mit.edu/gitweb/autoinstallsdev/mediawiki.git/blobdiff_plain/19e297c21b10b1b8a3acad5e73fc71dcb35db44a..6932310fd58ebef145fa01eb76edf7150284d8ea:/includes/MediaWikiServices.php

diff --git a/includes/MediaWikiServices.php b/includes/MediaWikiServices.php
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+<?php
+namespace MediaWiki;
+
+use Config;
+use ConfigFactory;
+use CryptHKDF;
+use CryptRand;
+use EventRelayerGroup;
+use GenderCache;
+use GlobalVarConfig;
+use Hooks;
+use IBufferingStatsdDataFactory;
+use MediaWiki\Shell\CommandFactory;
+use Wikimedia\Rdbms\LBFactory;
+use LinkCache;
+use Wikimedia\Rdbms\LoadBalancer;
+use MediaHandlerFactory;
+use MediaWiki\Linker\LinkRenderer;
+use MediaWiki\Linker\LinkRendererFactory;
+use MediaWiki\Services\SalvageableService;
+use MediaWiki\Services\ServiceContainer;
+use MediaWiki\Services\NoSuchServiceException;
+use MWException;
+use MimeAnalyzer;
+use ObjectCache;
+use Parser;
+use ParserCache;
+use ProxyLookup;
+use SearchEngine;
+use SearchEngineConfig;
+use SearchEngineFactory;
+use SiteLookup;
+use SiteStore;
+use WatchedItemStore;
+use WatchedItemQueryService;
+use SkinFactory;
+use TitleFormatter;
+use TitleParser;
+use VirtualRESTServiceClient;
+use MediaWiki\Interwiki\InterwikiLookup;
+
+/**
+ * Service locator for MediaWiki core services.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ *
+ * @since 1.27
+ */
+
+/**
+ * MediaWikiServices is the service locator for the application scope of MediaWiki.
+ * Its implemented as a simple configurable DI container.
+ * MediaWikiServices acts as a top level factory/registry for top level services, and builds
+ * the network of service objects that defines MediaWiki's application logic.
+ * It acts as an entry point to MediaWiki's dependency injection mechanism.
+ *
+ * Services are defined in the "wiring" array passed to the constructor,
+ * or by calling defineService().
+ *
+ * @see docs/injection.txt for an overview of using dependency injection in the
+ *      MediaWiki code base.
+ */
+class MediaWikiServices extends ServiceContainer {
+
+	/**
+	 * @var MediaWikiServices|null
+	 */
+	private static $instance = null;
+
+	/**
+	 * Returns the global default instance of the top level service locator.
+	 *
+	 * @since 1.27
+	 *
+	 * The default instance is initialized using the service instantiator functions
+	 * defined in ServiceWiring.php.
+	 *
+	 * @note This should only be called by static functions! The instance returned here
+	 * should not be passed around! Objects that need access to a service should have
+	 * that service injected into the constructor, never a service locator!
+	 *
+	 * @return MediaWikiServices
+	 */
+	public static function getInstance() {
+		if ( self::$instance === null ) {
+			// NOTE: constructing GlobalVarConfig here is not particularly pretty,
+			// but some information from the global scope has to be injected here,
+			// even if it's just a file name or database credentials to load
+			// configuration from.
+			$bootstrapConfig = new GlobalVarConfig();
+			self::$instance = self::newInstance( $bootstrapConfig, 'load' );
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * Replaces the global MediaWikiServices instance.
+	 *
+	 * @since 1.28
+	 *
+	 * @note This is for use in PHPUnit tests only!
+	 *
+	 * @throws MWException if called outside of PHPUnit tests.
+	 *
+	 * @param MediaWikiServices $services The new MediaWikiServices object.
+	 *
+	 * @return MediaWikiServices The old MediaWikiServices object, so it can be restored later.
+	 */
+	public static function forceGlobalInstance( MediaWikiServices $services ) {
+		if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
+			throw new MWException( __METHOD__ . ' must not be used outside unit tests.' );
+		}
+
+		$old = self::getInstance();
+		self::$instance = $services;
+
+		return $old;
+	}
+
+	/**
+	 * Creates a new instance of MediaWikiServices and sets it as the global default
+	 * instance. getInstance() will return a different MediaWikiServices object
+	 * after every call to resetGlobalInstance().
+	 *
+	 * @since 1.28
+	 *
+	 * @warning This should not be used during normal operation. It is intended for use
+	 * when the configuration has changed significantly since bootstrap time, e.g.
+	 * during the installation process or during testing.
+	 *
+	 * @warning Calling resetGlobalInstance() may leave the application in an inconsistent
+	 * state. Calling this is only safe under the ASSUMPTION that NO REFERENCE to
+	 * any of the services managed by MediaWikiServices exist. If any service objects
+	 * managed by the old MediaWikiServices instance remain in use, they may INTERFERE
+	 * with the operation of the services managed by the new MediaWikiServices.
+	 * Operating with a mix of services created by the old and the new
+	 * MediaWikiServices instance may lead to INCONSISTENCIES and even DATA LOSS!
+	 * Any class implementing LAZY LOADING is especially prone to this problem,
+	 * since instances would typically retain a reference to a storage layer service.
+	 *
+	 * @see forceGlobalInstance()
+	 * @see resetGlobalInstance()
+	 * @see resetBetweenTest()
+	 *
+	 * @param Config|null $bootstrapConfig The Config object to be registered as the
+	 *        'BootstrapConfig' service. This has to contain at least the information
+	 *        needed to set up the 'ConfigFactory' service. If not given, the bootstrap
+	 *        config of the old instance of MediaWikiServices will be re-used. If there
+	 *        was no previous instance, a new GlobalVarConfig object will be used to
+	 *        bootstrap the services.
+	 *
+	 * @param string $quick Set this to "quick" to allow expensive resources to be re-used.
+	 * See SalvageableService for details.
+	 *
+	 * @throws MWException If called after MW_SERVICE_BOOTSTRAP_COMPLETE has been defined in
+	 *         Setup.php (unless MW_PHPUNIT_TEST or MEDIAWIKI_INSTALL or RUN_MAINTENANCE_IF_MAIN
+	 *          is defined).
+	 */
+	public static function resetGlobalInstance( Config $bootstrapConfig = null, $quick = '' ) {
+		if ( self::$instance === null ) {
+			// no global instance yet, nothing to reset
+			return;
+		}
+
+		self::failIfResetNotAllowed( __METHOD__ );
+
+		if ( $bootstrapConfig === null ) {
+			$bootstrapConfig = self::$instance->getBootstrapConfig();
+		}
+
+		$oldInstance = self::$instance;
+
+		self::$instance = self::newInstance( $bootstrapConfig, 'load' );
+		self::$instance->importWiring( $oldInstance, [ 'BootstrapConfig' ] );
+
+		if ( $quick === 'quick' ) {
+			self::$instance->salvage( $oldInstance );
+		} else {
+			$oldInstance->destroy();
+		}
+	}
+
+	/**
+	 * Salvages the state of any salvageable service instances in $other.
+	 *
+	 * @note $other will have been destroyed when salvage() returns.
+	 *
+	 * @param MediaWikiServices $other
+	 */
+	private function salvage( self $other ) {
+		foreach ( $this->getServiceNames() as $name ) {
+			// The service could be new in the new instance and not registered in the
+			// other instance (e.g. an extension that was loaded after the instantiation of
+			// the other instance. Skip this service in this case. See T143974
+			try {
+				$oldService = $other->peekService( $name );
+			} catch ( NoSuchServiceException $e ) {
+				continue;
+			}
+
+			if ( $oldService instanceof SalvageableService ) {
+				/** @var SalvageableService $newService */
+				$newService = $this->getService( $name );
+				$newService->salvage( $oldService );
+			}
+		}
+
+		$other->destroy();
+	}
+
+	/**
+	 * Creates a new MediaWikiServices instance and initializes it according to the
+	 * given $bootstrapConfig. In particular, all wiring files defined in the
+	 * ServiceWiringFiles setting are loaded, and the MediaWikiServices hook is called.
+	 *
+	 * @param Config|null $bootstrapConfig The Config object to be registered as the
+	 *        'BootstrapConfig' service.
+	 *
+	 * @param string $loadWiring set this to 'load' to load the wiring files specified
+	 *        in the 'ServiceWiringFiles' setting in $bootstrapConfig.
+	 *
+	 * @return MediaWikiServices
+	 * @throws MWException
+	 * @throws \FatalError
+	 */
+	private static function newInstance( Config $bootstrapConfig, $loadWiring = '' ) {
+		$instance = new self( $bootstrapConfig );
+
+		// Load the default wiring from the specified files.
+		if ( $loadWiring === 'load' ) {
+			$wiringFiles = $bootstrapConfig->get( 'ServiceWiringFiles' );
+			$instance->loadWiringFiles( $wiringFiles );
+		}
+
+		// Provide a traditional hook point to allow extensions to configure services.
+		Hooks::run( 'MediaWikiServices', [ $instance ] );
+
+		return $instance;
+	}
+
+	/**
+	 * Disables all storage layer services. After calling this, any attempt to access the
+	 * storage layer will result in an error. Use resetGlobalInstance() to restore normal
+	 * operation.
+	 *
+	 * @since 1.28
+	 *
+	 * @warning This is intended for extreme situations only and should never be used
+	 * while serving normal web requests. Legitimate use cases for this method include
+	 * the installation process. Test fixtures may also use this, if the fixture relies
+	 * on globalState.
+	 *
+	 * @see resetGlobalInstance()
+	 * @see resetChildProcessServices()
+	 */
+	public static function disableStorageBackend() {
+		// TODO: also disable some Caches, JobQueues, etc
+		$destroy = [ 'DBLoadBalancer', 'DBLoadBalancerFactory' ];
+		$services = self::getInstance();
+
+		foreach ( $destroy as $name ) {
+			$services->disableService( $name );
+		}
+
+		ObjectCache::clear();
+	}
+
+	/**
+	 * Resets any services that may have become stale after a child process
+	 * returns from after pcntl_fork(). It's also safe, but generally unnecessary,
+	 * to call this method from the parent process.
+	 *
+	 * @since 1.28
+	 *
+	 * @note This is intended for use in the context of process forking only!
+	 *
+	 * @see resetGlobalInstance()
+	 * @see disableStorageBackend()
+	 */
+	public static function resetChildProcessServices() {
+		// NOTE: for now, just reset everything. Since we don't know the interdependencies
+		// between services, we can't do this more selectively at this time.
+		self::resetGlobalInstance();
+
+		// Child, reseed because there is no bug in PHP:
+		// https://bugs.php.net/bug.php?id=42465
+		mt_srand( getmypid() );
+	}
+
+	/**
+	 * Resets the given service for testing purposes.
+	 *
+	 * @since 1.28
+	 *
+	 * @warning This is generally unsafe! Other services may still retain references
+	 * to the stale service instance, leading to failures and inconsistencies. Subclasses
+	 * may use this method to reset specific services under specific instances, but
+	 * it should not be exposed to application logic.
+	 *
+	 * @note With proper dependency injection used throughout the codebase, this method
+	 * should not be needed. It is provided to allow tests that pollute global service
+	 * instances to clean up.
+	 *
+	 * @param string $name
+	 * @param bool $destroy Whether the service instance should be destroyed if it exists.
+	 *        When set to false, any existing service instance will effectively be detached
+	 *        from the container.
+	 *
+	 * @throws MWException if called outside of PHPUnit tests.
+	 */
+	public function resetServiceForTesting( $name, $destroy = true ) {
+		if ( !defined( 'MW_PHPUNIT_TEST' ) && !defined( 'MW_PARSER_TEST' ) ) {
+			throw new MWException( 'resetServiceForTesting() must not be used outside unit tests.' );
+		}
+
+		$this->resetService( $name, $destroy );
+	}
+
+	/**
+	 * Convenience method that throws an exception unless it is called during a phase in which
+	 * resetting of global services is allowed. In general, services should not be reset
+	 * individually, since that may introduce inconsistencies.
+	 *
+	 * @since 1.28
+	 *
+	 * This method will throw an exception if:
+	 *
+	 * - self::$resetInProgress is false (to allow all services to be reset together
+	 *   via resetGlobalInstance)
+	 * - and MEDIAWIKI_INSTALL is not defined (to allow services to be reset during installation)
+	 * - and MW_PHPUNIT_TEST is not defined (to allow services to be reset during testing)
+	 *
+	 * This method is intended to be used to safeguard against accidentally resetting
+	 * global service instances that are not yet managed by MediaWikiServices. It is
+	 * defined here in the MediaWikiServices services class to have a central place
+	 * for managing service bootstrapping and resetting.
+	 *
+	 * @param string $method the name of the caller method, as given by __METHOD__.
+	 *
+	 * @throws MWException if called outside bootstrap mode.
+	 *
+	 * @see resetGlobalInstance()
+	 * @see forceGlobalInstance()
+	 * @see disableStorageBackend()
+	 */
+	public static function failIfResetNotAllowed( $method ) {
+		if ( !defined( 'MW_PHPUNIT_TEST' )
+			&& !defined( 'MW_PARSER_TEST' )
+			&& !defined( 'MEDIAWIKI_INSTALL' )
+			&& !defined( 'RUN_MAINTENANCE_IF_MAIN' )
+			&& defined( 'MW_SERVICE_BOOTSTRAP_COMPLETE' )
+		) {
+			throw new MWException( $method . ' may only be called during bootstrapping and unit tests!' );
+		}
+	}
+
+	/**
+	 * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
+	 *        This has to contain at least the information needed to set up the 'ConfigFactory'
+	 *        service.
+	 */
+	public function __construct( Config $config ) {
+		parent::__construct();
+
+		// Register the given Config object as the bootstrap config service.
+		$this->defineService( 'BootstrapConfig', function () use ( $config ) {
+			return $config;
+		} );
+	}
+
+	// CONVENIENCE GETTERS ////////////////////////////////////////////////////
+
+	/**
+	 * Returns the Config object containing the bootstrap configuration.
+	 * Bootstrap configuration would typically include database credentials
+	 * and other information that may be needed before the ConfigFactory
+	 * service can be instantiated.
+	 *
+	 * @note This should only be used during bootstrapping, in particular
+	 * when creating the MainConfig service. Application logic should
+	 * use getMainConfig() to get a Config instances.
+	 *
+	 * @since 1.27
+	 * @return Config
+	 */
+	public function getBootstrapConfig() {
+		return $this->getService( 'BootstrapConfig' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return ConfigFactory
+	 */
+	public function getConfigFactory() {
+		return $this->getService( 'ConfigFactory' );
+	}
+
+	/**
+	 * Returns the Config object that provides configuration for MediaWiki core.
+	 * This may or may not be the same object that is returned by getBootstrapConfig().
+	 *
+	 * @since 1.27
+	 * @return Config
+	 */
+	public function getMainConfig() {
+		return $this->getService( 'MainConfig' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return SiteLookup
+	 */
+	public function getSiteLookup() {
+		return $this->getService( 'SiteLookup' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return SiteStore
+	 */
+	public function getSiteStore() {
+		return $this->getService( 'SiteStore' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return InterwikiLookup
+	 */
+	public function getInterwikiLookup() {
+		return $this->getService( 'InterwikiLookup' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return IBufferingStatsdDataFactory
+	 */
+	public function getStatsdDataFactory() {
+		return $this->getService( 'StatsdDataFactory' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return EventRelayerGroup
+	 */
+	public function getEventRelayerGroup() {
+		return $this->getService( 'EventRelayerGroup' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return SearchEngine
+	 */
+	public function newSearchEngine() {
+		// New engine object every time, since they keep state
+		return $this->getService( 'SearchEngineFactory' )->create();
+	}
+
+	/**
+	 * @since 1.27
+	 * @return SearchEngineFactory
+	 */
+	public function getSearchEngineFactory() {
+		return $this->getService( 'SearchEngineFactory' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return SearchEngineConfig
+	 */
+	public function getSearchEngineConfig() {
+		return $this->getService( 'SearchEngineConfig' );
+	}
+
+	/**
+	 * @since 1.27
+	 * @return SkinFactory
+	 */
+	public function getSkinFactory() {
+		return $this->getService( 'SkinFactory' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return LBFactory
+	 */
+	public function getDBLoadBalancerFactory() {
+		return $this->getService( 'DBLoadBalancerFactory' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return LoadBalancer The main DB load balancer for the local wiki.
+	 */
+	public function getDBLoadBalancer() {
+		return $this->getService( 'DBLoadBalancer' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return WatchedItemStore
+	 */
+	public function getWatchedItemStore() {
+		return $this->getService( 'WatchedItemStore' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return WatchedItemQueryService
+	 */
+	public function getWatchedItemQueryService() {
+		return $this->getService( 'WatchedItemQueryService' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return CryptRand
+	 */
+	public function getCryptRand() {
+		return $this->getService( 'CryptRand' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return CryptHKDF
+	 */
+	public function getCryptHKDF() {
+		return $this->getService( 'CryptHKDF' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return MediaHandlerFactory
+	 */
+	public function getMediaHandlerFactory() {
+		return $this->getService( 'MediaHandlerFactory' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return MimeAnalyzer
+	 */
+	public function getMimeAnalyzer() {
+		return $this->getService( 'MimeAnalyzer' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return ProxyLookup
+	 */
+	public function getProxyLookup() {
+		return $this->getService( 'ProxyLookup' );
+	}
+
+	/**
+	 * @since 1.29
+	 * @return Parser
+	 */
+	public function getParser() {
+		return $this->getService( 'Parser' );
+	}
+
+	/**
+	 * @since 1.30
+	 * @return ParserCache
+	 */
+	public function getParserCache() {
+		return $this->getService( 'ParserCache' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return GenderCache
+	 */
+	public function getGenderCache() {
+		return $this->getService( 'GenderCache' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return LinkCache
+	 */
+	public function getLinkCache() {
+		return $this->getService( 'LinkCache' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return LinkRendererFactory
+	 */
+	public function getLinkRendererFactory() {
+		return $this->getService( 'LinkRendererFactory' );
+	}
+
+	/**
+	 * LinkRenderer instance that can be used
+	 * if no custom options are needed
+	 *
+	 * @since 1.28
+	 * @return LinkRenderer
+	 */
+	public function getLinkRenderer() {
+		return $this->getService( 'LinkRenderer' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return TitleFormatter
+	 */
+	public function getTitleFormatter() {
+		return $this->getService( 'TitleFormatter' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return TitleParser
+	 */
+	public function getTitleParser() {
+		return $this->getService( 'TitleParser' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return \BagOStuff
+	 */
+	public function getMainObjectStash() {
+		return $this->getService( 'MainObjectStash' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return \WANObjectCache
+	 */
+	public function getMainWANObjectCache() {
+		return $this->getService( 'MainWANObjectCache' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return \BagOStuff
+	 */
+	public function getLocalServerObjectCache() {
+		return $this->getService( 'LocalServerObjectCache' );
+	}
+
+	/**
+	 * @since 1.28
+	 * @return VirtualRESTServiceClient
+	 */
+	public function getVirtualRESTServiceClient() {
+		return $this->getService( 'VirtualRESTServiceClient' );
+	}
+
+	/**
+	 * @since 1.29
+	 * @return \ConfiguredReadOnlyMode
+	 */
+	public function getConfiguredReadOnlyMode() {
+		return $this->getService( 'ConfiguredReadOnlyMode' );
+	}
+
+	/**
+	 * @since 1.29
+	 * @return \ReadOnlyMode
+	 */
+	public function getReadOnlyMode() {
+		return $this->getService( 'ReadOnlyMode' );
+	}
+
+	/**
+	 * @since 1.30
+	 * @return CommandFactory
+	 */
+	public function getShellCommandFactory() {
+		return $this->getService( 'ShellCommandFactory' );
+	}
+
+	///////////////////////////////////////////////////////////////////////////
+	// NOTE: When adding a service getter here, don't forget to add a test
+	// case for it in MediaWikiServicesTest::provideGetters() and in
+	// MediaWikiServicesTest::provideGetService()!
+	///////////////////////////////////////////////////////////////////////////
+
+}