class TraceableEventDispatcher

class TraceableEventDispatcher extends ContainerAwareEventDispatcher implements EventDispatcherTraceableInterface {
    
    /**
     * @var \Drupal\webprofiler\Stopwatch
     *   The stopwatch service.
     */
    protected $stopwatch;
    
    /**
     * @var array
     */
    protected $calledListeners;
    
    /**
     * @var array
     */
    protected $notCalledListeners;
    
    /**
     * {@inheritdoc}
     */
    public function __construct(ContainerInterface $container, array $listeners = []) {
        parent::__construct($container, $listeners);
        $this->notCalledListeners = $listeners;
    }
    
    /**
     * {@inheritdoc}
     */
    public function addListener($event_name, $listener, $priority = 0) {
        parent::addListener($event_name, $listener, $priority);
        $this->notCalledListeners[$event_name][$priority][] = [
            'callable' => $listener,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function dispatch($event_name, Event $event = NULL) {
        if ($event === NULL) {
            $event = new Event();
        }
        $this->preDispatch($event_name, $event);
        $e = $this->stopwatch
            ->start($event_name, 'section');
        if (isset($this->listeners[$event_name])) {
            // Sort listeners if necessary.
            if (isset($this->unsorted[$event_name])) {
                krsort($this->listeners[$event_name]);
                unset($this->unsorted[$event_name]);
            }
            // Invoke listeners and resolve callables if necessary.
            foreach ($this->listeners[$event_name] as $priority => &$definitions) {
                foreach ($definitions as $key => &$definition) {
                    if (!isset($definition['callable'])) {
                        $definition['callable'] = [
                            $this->container
                                ->get($definition['service'][0]),
                            $definition['service'][1],
                        ];
                    }
                    $definition['callable']($event, $event_name, $this);
                    $this->addCalledListener($definition, $event_name, $priority);
                    if ($event->isPropagationStopped()) {
                        return $event;
                    }
                }
            }
        }
        if ($e->isStarted()) {
            $e->stop();
        }
        $this->postDispatch($event_name, $event);
        return $event;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCalledListeners() {
        return $this->calledListeners;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getNotCalledListeners() {
        return $this->notCalledListeners;
    }
    
    /**
     * @param \Drupal\webprofiler\Stopwatch $stopwatch
     */
    public function setStopwatch(Stopwatch $stopwatch) {
        $this->stopwatch = $stopwatch;
    }
    
    /**
     * Called before dispatching the event.
     *
     * @param string $eventName The event name
     * @param Event $event The event
     */
    protected function preDispatch($eventName, Event $event) {
        switch ($eventName) {
            case KernelEvents::VIEW:
            case KernelEvents::RESPONSE:
                // stop only if a controller has been executed
                if ($this->stopwatch
                    ->isStarted('controller')) {
                    $this->stopwatch
                        ->stop('controller');
                }
                break;
        }
    }
    
    /**
     * Called after dispatching the event.
     *
     * @param string $eventName The event name
     * @param Event $event The event
     */
    protected function postDispatch($eventName, Event $event) {
        switch ($eventName) {
            case KernelEvents::CONTROLLER:
                $this->stopwatch
                    ->start('controller', 'section');
                break;
            case KernelEvents::RESPONSE:
                $token = $event->getResponse()->headers
                    ->get('X-Debug-Token');
                try {
                    $this->stopwatch
                        ->stopSection($token);
                } catch (\LogicException $e) {
                }
                break;
            case KernelEvents::TERMINATE:
                // In the special case described in the `preDispatch` method above, the `$token` section
                // does not exist, then closing it throws an exception which must be caught.
                $token = $event->getResponse()->headers
                    ->get('X-Debug-Token');
                try {
                    $this->stopwatch
                        ->stopSection($token);
                } catch (\LogicException $e) {
                }
                break;
        }
    }
    
    /**
     * @param $definition
     * @param $event_name
     * @param $priority
     */
    private function addCalledListener($definition, $event_name, $priority) {
        if ($this->isClosure($definition['callable'])) {
            $this->calledListeners[$event_name][$priority][] = [
                'class' => 'Closure',
                'method' => '',
            ];
        }
        else {
            $this->calledListeners[$event_name][$priority][] = [
                'class' => get_class($definition['callable'][0]),
                'method' => $definition['callable'][1],
            ];
        }
        foreach ($this->notCalledListeners[$event_name][$priority] as $key => $listener) {
            if (isset($listener['service'])) {
                if ($listener['service'][0] == $definition['service'][0] && $listener['service'][1] == $definition['service'][1]) {
                    unset($this->notCalledListeners[$event_name][$priority][$key]);
                }
            }
            else {
                if ($this->isClosure($listener['callable'])) {
                    if (is_callable($listener['callable'], TRUE, $listenerCallableName) && is_callable($definition['callable'], TRUE, $definitionCallableName)) {
                        if ($listenerCallableName == $definitionCallableName) {
                            unset($this->notCalledListeners[$event_name][$priority][$key]);
                        }
                    }
                }
                else {
                    if (get_class($listener['callable'][0]) == get_class($definition['callable'][0]) && $listener['callable'][1] == $definition['callable'][1]) {
                        unset($this->notCalledListeners[$event_name][$priority][$key]);
                    }
                }
            }
        }
    }
    private function isClosure($t) {
        return is_object($t) && $t instanceof \Closure;
    }

}