Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Component\EventDispatcher;
Chris@0: 
Chris@0: use Symfony\Component\DependencyInjection\ContainerInterface;
Chris@0: use Symfony\Component\EventDispatcher\Event;
Chris@0: use Symfony\Component\EventDispatcher\EventDispatcherInterface;
Chris@0: use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * A performance optimized container aware event dispatcher.
Chris@0:  *
Chris@0:  * This version of the event dispatcher contains the following optimizations
Chris@0:  * in comparison to the Symfony event dispatcher component:
Chris@0:  *
Chris@0:  * <dl>
Chris@0:  *   <dt>Faster instantiation of the event dispatcher service</dt>
Chris@0:  *   <dd>
Chris@0:  *     Instead of calling <code>addSubscriberService</code> once for each
Chris@0:  *     subscriber, a precompiled array of listener definitions is passed
Chris@0:  *     directly to the constructor. This is faster by roughly an order of
Chris@0:  *     magnitude. The listeners are collected and prepared using a compiler
Chris@0:  *     pass.
Chris@0:  *   </dd>
Chris@0:  *   <dt>Lazy instantiation of listeners</dt>
Chris@0:  *   <dd>
Chris@0:  *     Services are only retrieved from the container just before invocation.
Chris@0:  *     Especially when dispatching the KernelEvents::REQUEST event, this leads
Chris@0:  *     to a more timely invocation of the first listener. Overall dispatch
Chris@0:  *     runtime is not affected by this change though.
Chris@0:  *   </dd>
Chris@0:  * </dl>
Chris@0:  */
Chris@0: class ContainerAwareEventDispatcher implements EventDispatcherInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The service container.
Chris@0:    *
Chris@17:    * @var \Symfony\Component\DependencyInjection\ContainerInterface
Chris@0:    */
Chris@0:   protected $container;
Chris@0: 
Chris@0:   /**
Chris@0:    * Listener definitions.
Chris@0:    *
Chris@0:    * A nested array of listener definitions keyed by event name and priority.
Chris@0:    * A listener definition is an associative array with one of the following key
Chris@0:    * value pairs:
Chris@0:    * - callable: A callable listener
Chris@0:    * - service: An array of the form [service id, method]
Chris@0:    *
Chris@0:    * A service entry will be resolved to a callable only just before its
Chris@0:    * invocation.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $listeners;
Chris@0: 
Chris@0:   /**
Chris@0:    * Whether listeners need to be sorted prior to dispatch, keyed by event name.
Chris@0:    *
Chris@0:    * @var TRUE[]
Chris@0:    */
Chris@0:   protected $unsorted;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a container aware event dispatcher.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
Chris@0:    *   The service container.
Chris@0:    * @param array $listeners
Chris@0:    *   A nested array of listener definitions keyed by event name and priority.
Chris@0:    *   The array is expected to be ordered by priority. A listener definition is
Chris@0:    *   an associative array with one of the following key value pairs:
Chris@0:    *   - callable: A callable listener
Chris@0:    *   - service: An array of the form [service id, method]
Chris@0:    *   A service entry will be resolved to a callable only just before its
Chris@0:    *   invocation.
Chris@0:    */
Chris@0:   public function __construct(ContainerInterface $container, array $listeners = []) {
Chris@0:     $this->container = $container;
Chris@0:     $this->listeners = $listeners;
Chris@0:     $this->unsorted = [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function dispatch($event_name, Event $event = NULL) {
Chris@0:     if ($event === NULL) {
Chris@0:       $event = new Event();
Chris@0:     }
Chris@0: 
Chris@0:     if (isset($this->listeners[$event_name])) {
Chris@0:       // Sort listeners if necessary.
Chris@0:       if (isset($this->unsorted[$event_name])) {
Chris@0:         krsort($this->listeners[$event_name]);
Chris@0:         unset($this->unsorted[$event_name]);
Chris@0:       }
Chris@0: 
Chris@0:       // Invoke listeners and resolve callables if necessary.
Chris@0:       foreach ($this->listeners[$event_name] as $priority => &$definitions) {
Chris@0:         foreach ($definitions as $key => &$definition) {
Chris@0:           if (!isset($definition['callable'])) {
Chris@0:             $definition['callable'] = [$this->container->get($definition['service'][0]), $definition['service'][1]];
Chris@0:           }
Chris@14:           if (is_array($definition['callable']) && isset($definition['callable'][0]) && $definition['callable'][0] instanceof \Closure) {
Chris@14:             $definition['callable'][0] = $definition['callable'][0]();
Chris@14:           }
Chris@0: 
Chris@14:           call_user_func($definition['callable'], $event, $event_name, $this);
Chris@0:           if ($event->isPropagationStopped()) {
Chris@0:             return $event;
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $event;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getListeners($event_name = NULL) {
Chris@0:     $result = [];
Chris@0: 
Chris@0:     if ($event_name === NULL) {
Chris@0:       // If event name was omitted, collect all listeners of all events.
Chris@0:       foreach (array_keys($this->listeners) as $event_name) {
Chris@0:         $listeners = $this->getListeners($event_name);
Chris@0:         if (!empty($listeners)) {
Chris@0:           $result[$event_name] = $listeners;
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:     elseif (isset($this->listeners[$event_name])) {
Chris@0:       // Sort listeners if necessary.
Chris@0:       if (isset($this->unsorted[$event_name])) {
Chris@0:         krsort($this->listeners[$event_name]);
Chris@0:         unset($this->unsorted[$event_name]);
Chris@0:       }
Chris@0: 
Chris@0:       // Collect listeners and resolve callables if necessary.
Chris@0:       foreach ($this->listeners[$event_name] as $priority => &$definitions) {
Chris@0:         foreach ($definitions as $key => &$definition) {
Chris@0:           if (!isset($definition['callable'])) {
Chris@0:             $definition['callable'] = [$this->container->get($definition['service'][0]), $definition['service'][1]];
Chris@0:           }
Chris@14:           if (is_array($definition['callable']) && isset($definition['callable'][0]) && $definition['callable'][0] instanceof \Closure) {
Chris@14:             $definition['callable'][0] = $definition['callable'][0]();
Chris@14:           }
Chris@0: 
Chris@0:           $result[] = $definition['callable'];
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $result;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@14:   public function getListenerPriority($event_name, $listener) {
Chris@14:     if (!isset($this->listeners[$event_name])) {
Chris@0:       return;
Chris@0:     }
Chris@14:     if (is_array($listener) && isset($listener[0]) && $listener[0] instanceof \Closure) {
Chris@14:       $listener[0] = $listener[0]();
Chris@0:     }
Chris@0:     // Resolve service definitions if the listener has not been found so far.
Chris@14:     foreach ($this->listeners[$event_name] as $priority => &$definitions) {
Chris@0:       foreach ($definitions as $key => &$definition) {
Chris@0:         if (!isset($definition['callable'])) {
Chris@0:           // Once the callable is retrieved we keep it for subsequent method
Chris@0:           // invocations on this class.
Chris@14:           $definition['callable'] = [
Chris@14:             $this->container->get($definition['service'][0]),
Chris@14:             $definition['service'][1],
Chris@14:           ];
Chris@14:         }
Chris@14:         if (is_array($definition['callable']) && isset($definition['callable'][0]) && $definition['callable'][0] instanceof \Closure) {
Chris@14:           $definition['callable'][0] = $definition['callable'][0]();
Chris@14:         }
Chris@14:         if ($definition['callable'] === $listener) {
Chris@14:           return $priority;
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function hasListeners($event_name = NULL) {
Chris@14:     if ($event_name !== NULL) {
Chris@14:       return !empty($this->listeners[$event_name]);
Chris@14:     }
Chris@14: 
Chris@14:     foreach ($this->listeners as $event_listeners) {
Chris@14:       if ($event_listeners) {
Chris@14:         return TRUE;
Chris@14:       }
Chris@14:     }
Chris@14: 
Chris@14:     return FALSE;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function addListener($event_name, $listener, $priority = 0) {
Chris@0:     $this->listeners[$event_name][$priority][] = ['callable' => $listener];
Chris@0:     $this->unsorted[$event_name] = TRUE;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function removeListener($event_name, $listener) {
Chris@0:     if (!isset($this->listeners[$event_name])) {
Chris@0:       return;
Chris@0:     }
Chris@0: 
Chris@0:     foreach ($this->listeners[$event_name] as $priority => $definitions) {
Chris@0:       foreach ($definitions as $key => $definition) {
Chris@0:         if (!isset($definition['callable'])) {
Chris@0:           if (!$this->container->initialized($definition['service'][0])) {
Chris@0:             continue;
Chris@0:           }
Chris@0:           $definition['callable'] = [$this->container->get($definition['service'][0]), $definition['service'][1]];
Chris@0:         }
Chris@0: 
Chris@14:         if (is_array($definition['callable']) && isset($definition['callable'][0]) && $definition['callable'][0] instanceof \Closure && !$listener instanceof \Closure) {
Chris@14:           $definition['callable'][0] = $definition['callable'][0]();
Chris@14:         }
Chris@14: 
Chris@14:         if (is_array($definition['callable']) && isset($definition['callable'][0]) && !$definition['callable'][0] instanceof \Closure && is_array($listener) && isset($listener[0]) && $listener[0] instanceof \Closure) {
Chris@14:           $listener[0] = $listener[0]();
Chris@14:         }
Chris@0:         if ($definition['callable'] === $listener) {
Chris@14:           unset($definitions[$key]);
Chris@0:         }
Chris@0:       }
Chris@14:       if ($definitions) {
Chris@14:         $this->listeners[$event_name][$priority] = $definitions;
Chris@14:       }
Chris@14:       else {
Chris@14:         unset($this->listeners[$event_name][$priority]);
Chris@14:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function addSubscriber(EventSubscriberInterface $subscriber) {
Chris@0:     foreach ($subscriber->getSubscribedEvents() as $event_name => $params) {
Chris@0:       if (is_string($params)) {
Chris@0:         $this->addListener($event_name, [$subscriber, $params]);
Chris@0:       }
Chris@0:       elseif (is_string($params[0])) {
Chris@0:         $this->addListener($event_name, [$subscriber, $params[0]], isset($params[1]) ? $params[1] : 0);
Chris@0:       }
Chris@0:       else {
Chris@0:         foreach ($params as $listener) {
Chris@0:           $this->addListener($event_name, [$subscriber, $listener[0]], isset($listener[1]) ? $listener[1] : 0);
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function removeSubscriber(EventSubscriberInterface $subscriber) {
Chris@0:     foreach ($subscriber->getSubscribedEvents() as $event_name => $params) {
Chris@0:       if (is_array($params) && is_array($params[0])) {
Chris@0:         foreach ($params as $listener) {
Chris@0:           $this->removeListener($event_name, [$subscriber, $listener[0]]);
Chris@0:         }
Chris@0:       }
Chris@0:       else {
Chris@0:         $this->removeListener($event_name, [$subscriber, is_string($params) ? $params : $params[0]]);
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0: }