Merge "Make Special:ChangeContentModel field labels consistently use colons"

[lhc/web/wiklou.git] / includes / libs / services / ServiceContainer.php

diff --git a/includes/libs/services/ServiceContainer.php b/includes/libs/services/ServiceContainer.php
index dd0d081..84755ed 100644 (file)
--- a/includes/libs/services/ServiceContainer.php
+++ b/includes/libs/services/ServiceContainer.php
@@ -3,8 +3,10 @@
 namespace Wikimedia\Services;
 
 use InvalidArgumentException;
+use Psr\Container\ContainerInterface;
 use RuntimeException;
 use Wikimedia\Assert\Assert;
+use Wikimedia\ScopedCallback;
 
 /**
  * Generic service container.
@@ -44,7 +46,7 @@ use Wikimedia\Assert\Assert;
  * @see docs/injection.txt for an overview of using dependency injection in the
  *      MediaWiki code base.
  */
-class ServiceContainer implements DestructibleService {
+class ServiceContainer implements ContainerInterface, DestructibleService {
 
        /**
         * @var object[]
@@ -76,6 +78,11 @@ class ServiceContainer implements DestructibleService {
         */
        private $destroyed = false;
 
+       /**
+        * @var array Set of services currently being created, to detect loops
+        */
+       private $servicesBeingCreated = [];
+
        /**
         * @param array $extraInstantiationParams Any additional parameters to be passed to the
         * instantiator function when creating a service. This is typically used to provide
@@ -193,6 +200,11 @@ class ServiceContainer implements DestructibleService {
                return isset( $this->serviceInstantiators[$name] );
        }
 
+       /** @inheritDoc */
+       public function has( $name ) {
+               return $this->hasService( $name );
+       }
+
        /**
         * Returns the service instance for $name only if that service has already been instantiated.
         * This is intended for situations where services get destroyed/cleaned up, so we can
@@ -418,14 +430,29 @@ class ServiceContainer implements DestructibleService {
                return $this->services[$name];
        }
 
+       /** @inheritDoc */
+       public function get( $name ) {
+               return $this->getService( $name );
+       }
+
        /**
         * @param string $name
         *
         * @throws InvalidArgumentException if $name is not a known service.
+        * @throws RuntimeException if a circular dependency is detected.
         * @return object
         */
        private function createService( $name ) {
                if ( isset( $this->serviceInstantiators[$name] ) ) {
+                       if ( isset( $this->servicesBeingCreated[$name] ) ) {
+                               throw new RuntimeException( "Circular dependency when creating service! " .
+                                       implode( ' -> ', array_keys( $this->servicesBeingCreated ) ) . " -> $name" );
+                       }
+                       $this->servicesBeingCreated[$name] = true;
+                       $removeFromStack = new ScopedCallback( function () use ( $name ) {
+                               unset( $this->servicesBeingCreated[$name] );
+                       } );
+
                        $service = ( $this->serviceInstantiators[$name] )(
                                $this,
                                ...$this->extraInstantiationParams
@@ -447,6 +474,8 @@ class ServiceContainer implements DestructibleService {
                                }
                        }
 
+                       $removeFromStack->consume();
+
                        // NOTE: when adding more wiring logic here, make sure importWiring() is kept in sync!
                } else {
                        throw new NoSuchServiceException( $name );