<?php
namespace MediaWiki;
+use Config;
use ConfigFactory;
use EventRelayerGroup;
use GlobalVarConfig;
-use Config;
use Hooks;
+use LBFactory;
use Liuggio\StatsdClient\Factory\StatsdDataFactory;
+use LoadBalancer;
use MediaWiki\Services\ServiceContainer;
+use MWException;
+use ResourceLoader;
use SearchEngine;
use SearchEngineConfig;
use SearchEngineFactory;
*/
class MediaWikiServices extends ServiceContainer {
+ /**
+ * @var MediaWikiServices|null
+ */
+ private static $instance = null;
+
/**
* Returns the global default instance of the top level service locator.
*
* @return MediaWikiServices
*/
public static function getInstance() {
- static $instance = null;
-
- if ( $instance === null ) {
+ if ( self::$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.
- $config = new GlobalVarConfig();
- $instance = new self( $config );
+ $bootstrapConfig = new GlobalVarConfig();
+ self::$instance = self::newInstance( $bootstrapConfig );
+ }
- // Load the default wiring from the specified files.
- $wiringFiles = $config->get( 'ServiceWiringFiles' );
- $instance->loadWiringFiles( $wiringFiles );
+ return self::$instance;
+ }
- // Provide a traditional hook point to allow extensions to configure services.
- Hooks::run( 'MediaWikiServices', [ $instance ] );
+ /**
+ * Replaces the global MediaWikiServices instance.
+ *
+ * @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 resetGlobalServiceLocator().
+ *
+ * @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 resetGlobalServiceLocator() 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.
+ *
+ * @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 $bootstrapConfig = null ) {
+ if ( self::$instance === null ) {
+ // no global instance yet, nothing to reset
+ return;
+ }
+
+ self::failIfResetNotAllowed( __METHOD__ );
+
+ if ( $bootstrapConfig === null ) {
+ $bootstrapConfig = self::$instance->getBootstrapConfig();
+ }
+
+ self::$instance->destroy();
+
+ self::$instance = self::newInstance( $bootstrapConfig );
+ }
+
+ /**
+ * 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. This has to contain at least the information
+ * needed to set up the 'ConfigFactory' service. If not provided, any call
+ * to getBootstrapConfig(), getConfigFactory, or getMainConfig will fail.
+ * A MediaWikiServices instance without access to configuration is called
+ * "primordial".
+ *
+ * @return MediaWikiServices
+ * @throws MWException
+ */
+ private static function newInstance( Config $bootstrapConfig ) {
+ $instance = new self( $bootstrapConfig );
+
+ // Load the default wiring from the specified files.
+ $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.
+ *
+ * @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 );
+ }
+ }
+
+ /**
+ * 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.
+ *
+ * @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.
+ *
+ * @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 string $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, $destroy );
+ }
+
+ /**
+ * Convenience method that throws an exception unless it is called during a phase in which
+ * resetting of global services is allowed. In general, services should not be reset
+ * individually, since that may introduce inconsistencies.
+ *
+ * This method will throw an exception if:
+ *
+ * - self::$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'
public function __construct( Config $config ) {
parent::__construct();
- // register the given Config object as the bootstrap config service.
+ // 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
return $this->getService( 'SkinFactory' );
}
+ /**
+ * @return LBFactory
+ */
+ public function getDBLoadBalancerFactory() {
+ return $this->getService( 'DBLoadBalancerFactory' );
+ }
+
+ /**
+ * @return LoadBalancer The main DB load balancer for the local wiki.
+ */
+ public function getDBLoadBalancer() {
+ return $this->getService( 'DBLoadBalancer' );
+ }
+
///////////////////////////////////////////////////////////////////////////
// NOTE: When adding a service getter here, don't forget to add a test
// case for it in MediaWikiServicesTest::provideGetters() and in
dépôts / lhc / web / wiklou.git / blobdiff