gistfile1.txt

diff --git a/core/lib/Drupal/Core/EventDispatcher/LiteEventDispatcher.php b/core/lib/Drupal/Core/EventDispatcher/LiteEventDispatcher.php
new file mode 100644
index 0000000..81d5987
--- /dev/null
+++ b/core/lib/Drupal/Core/EventDispatcher/LiteEventDispatcher.php
@@ -0,0 +1,194 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\EventDispatcher\LiteEventDispatcher.
+ */
+
+namespace Drupal\Core\EventDispatcher;
+
+use Symfony\Component\DependencyInjection\ContainerAwareInterface;
+use Symfony\Component\DependencyInjection\ContainerAwareTrait;
+use Symfony\Component\EventDispatcher\Event;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+class LiteEventDispatcher implements EventDispatcherInterface, ContainerAwareInterface {
+
+  use ContainerAwareTrait;
+
+  protected $listeners = array();
+  protected $sorted = array();
+
+  /**
+   * @var bool
+   */
+  protected $deferSort;
+
+  protected $containerSubscribers;
+  protected $services;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function dispatch($event_name, Event $event = NULL) {
+    if ($event === NULL) {
+      $event = new Event();
+    }
+
+    $event->setDispatcher($this);
+    $event->setName($event_name);
+
+    // @todo Is this actually a helpful optimization?
+    if (!isset($this->sorted[$event_name])) {
+      return $event;
+    }
+
+    // Ensure that code is just loaded if it is needed.
+    if (!isset($this->loaded[$event_name])) {
+      $this->lazyLoad($event_name);
+      $this->loaded[$event_name] = TRUE;
+    }
+
+    $this->doDispatch($this->sorted[$event_name], $event_name, $event);
+    return $event;
+  }
+
+  public function lazyLoad($event_name) {
+    foreach ($this->containerSubscribers as $service_name) {
+      if (!isset($this->services[$service_name])) {
+        $this->services[$service_name] = $this->container->get($service_name);
+      }
+    }
+  }
+
+  /**
+   * Triggers the listeners of an event.
+   *
+   * This method can be overridden to add functionality that is executed for
+   * each listener.
+   *
+   * @param callable[] $listeners
+   *   The event listeners.
+   * @param string $event_name
+   *   The name of the event to dispatch.
+   * @param \Symfony\Component\EventDispatcher\Event
+   *   $event The event object to pass to the event handlers/listeners.
+   */
+  protected function doDispatch($listeners, $event_name, Event $event) {
+    foreach ($listeners as $listener) {
+      call_user_func($listener, $event, $event_name, $this);
+    }
+  }
+
+  public function setDeferSorting($defer = TRUE) {
+    $this->deferSort = $defer;
+  }
+
+  public function sortAll() {
+    $this->sorted = array();
+
+    foreach ($this->listeners as $event_name => $event_listeners) {
+      krsort($this->listeners[$event_name]);
+      $this->sorted[$event_name] = call_user_func_array('array_merge', $this->listeners[$event_name]);
+    }
+  }
+
+  public function sort($event_name) {
+    krsort($this->listeners[$event_name]);
+    $this->sorted[$event_name] = call_user_func_array('array_merge', $this->listeners[$event_name]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addListener($eventName, $listener, $priority = 0) {
+    $this->listeners[$eventName][$priority][] = $listener;
+    if (!$this->deferSort) {
+      $this->sortAll();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addSubscriber(EventSubscriberInterface $subscriber) {
+    $events = array();
+    foreach ($subscriber->getSubscribedEvents() as $event_name => $params) {
+      if (is_string($params)) {
+        $this->addListener($event_name, array($subscriber, $params));
+      }
+      elseif (is_string($params[0])) {
+        $this->addListener($event_name, array($subscriber, $params[0]), isset($params[1]) ? $params[1] : 0);
+      }
+      else {
+        foreach ($params as $listener) {
+          $this->addListener($event_name, array($subscriber, $listener[0]), isset($listener[1]) ? $listener[1] : 0);
+        }
+      }
+      $events[$event_name] = $event_name;
+    }
+
+    foreach ($events as $event_name) {
+      $this->sort($event_name);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function removeListener($event_name, $listener) {
+    if (!isset($this->listeners[$event_name])) {
+      return;
+    }
+
+    foreach ($this->listeners[$event_name] as $priority => $listeners) {
+      if (($key = array_search($listener, $listeners, TRUE)) !== FALSE) {
+        unset($this->listeners[$event_name][$priority][$key], $this->sorted[$event_name]);
+      }
+    }
+
+    $this->sort($event_name);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function removeSubscriber(EventSubscriberInterface $subscriber) {
+    $events = array();
+    foreach ($subscriber->getSubscribedEvents() as $event_name => $params) {
+      if (is_array($params) && is_array($params[0])) {
+        foreach ($params as $listener) {
+          $this->removeListener($event_name, array($subscriber, $listener[0]));
+        }
+      }
+      else {
+        $this->removeListener($event_name, array($subscriber, is_string($params) ? $params : $params[0]));
+      }
+      $events[$event_name] = $event_name;
+    }
+
+    foreach ($events as $event_name) {
+      $this->sort($event_name);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getListeners($event_name = NULL) {
+    if ($event_name !== NULL) {
+      return $this->sorted[$event_name];
+    }
+    return $this->sorted;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasListeners($event_name = NULL) {
+    return (bool) count($this->getListeners($event_name));
+  }
+
+}
+