MediaWikiServices::getLinkCache() - Code Metrics - Inspection of "Daily Inspection: objectcache: add WANObjectCache:..." - wikimedia/mediawiki - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Branch — master (24200e)

unknown

created 2016-10-05 17:04 UTC

MediaWikiServices::getLinkCache() A

↳ Parent: MediaWikiServices

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	2
nc	1
nop	0
dl	0
loc	3
rs	10
c	0
b	0
f	0

<?php
namespace MediaWiki;

use Config;
use ConfigFactory;
use CryptRand;
use EventRelayerGroup;
use GenderCache;
use GlobalVarConfig;
use Hooks;
use LBFactory;
use LinkCache;
use Liuggio\StatsdClient\Factory\StatsdDataFactory;
use 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 ObjectCache;
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( $bootstrapConfig );
		self::$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:
		// http://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 StatsdDataFactory
	 */
	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 MediaHandlerFactory
	 */
	public function getMediaHandlerFactory() {
		return $this->getService( 'MediaHandlerFactory' );
	}

	/**
	 * @since 1.28
	 * @return ProxyLookup
	 */
	public function getProxyLookup() {
		return $this->getService( 'ProxyLookup' );
	}

	/**
	 * @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' );
	}

	///////////////////////////////////////////////////////////////////////////
	// NOTE: When adding a service getter here, don't forget to add a test
	// case for it in MediaWikiServicesTest::provideGetters() and in
	// MediaWikiServicesTest::provideGetService()!
	///////////////////////////////////////////////////////////////////////////

}


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

wikimedia / mediawiki

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MediaWikiServices::getLinkCache() A

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