ProfilerListener.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\HttpKernel\EventListener;

use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Profiler\Profile;
use Symfony\Component\HttpKernel\Profiler\Profiler;
use Symfony\Component\HttpFoundation\RequestMatcherInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * ProfilerListener collects data for the current request by listening to the onKernelResponse event.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class ProfilerListener implements EventSubscriberInterface {
  protected $profiler;
  protected $matcher;
  protected $onlyException;
  protected $onlyMasterRequests;
  protected $exception;
  protected $children;
  protected $requests;
  protected $profiles;

  /**
   * Constructor.
   *
   * @param Profiler                $profiler           A Profiler instance
   * @param RequestMatcherInterface $matcher            A RequestMatcher instance
   * @param Boolean                 $onlyException      true if the profiler only collects data when an exception occurs, false otherwise
   * @param Boolean                 $onlyMasterRequests true if the profiler only collects data when the request is a master request, false otherwise
   */
  public function __construct(Profiler $profiler, RequestMatcherInterface $matcher = null, $onlyException = false, $onlyMasterRequests = false) {
    $this->profiler = $profiler;
    $this->matcher = $matcher;
    $this->onlyException = (bool) $onlyException;
    $this->onlyMasterRequests = (bool) $onlyMasterRequests;
    $this->children = new \SplObjectStorage();
    $this->profiles = array();
  }

  /**
   * Handles the onKernelException event.
   *
   * @param GetResponseForExceptionEvent $event A GetResponseForExceptionEvent instance
   */
  public function onKernelException(GetResponseForExceptionEvent $event) {
    if ($this->onlyMasterRequests && HttpKernelInterface::MASTER_REQUEST !== $event
      ->getRequestType()) {
      return;
    }
    $this->exception = $event
      ->getException();
  }
  public function onKernelRequest(GetResponseEvent $event) {
    $this->requests[] = $event
      ->getRequest();
  }

  /**
   * Handles the onKernelResponse event.
   *
   * @param FilterResponseEvent $event A FilterResponseEvent instance
   */
  public function onKernelResponse(FilterResponseEvent $event) {
    $master = HttpKernelInterface::MASTER_REQUEST === $event
      ->getRequestType();
    if ($this->onlyMasterRequests && !$master) {
      return;
    }
    if ($this->onlyException && null === $this->exception) {
      return;
    }
    $request = $event
      ->getRequest();
    $exception = $this->exception;
    $this->exception = null;
    if (null !== $this->matcher && !$this->matcher
      ->matches($request)) {
      return;
    }
    if (!($profile = $this->profiler
      ->collect($request, $event
      ->getResponse(), $exception))) {
      return;
    }
    $this->profiles[] = $profile;
    if (null !== $exception) {
      foreach ($this->profiles as $profile) {
        $this->profiler
          ->saveProfile($profile);
      }
      return;
    }

    // keep the profile as the child of its parent
    if (!$master) {
      array_pop($this->requests);
      $parent = end($this->requests);

      // when simulating requests, we might not have the parent
      if ($parent) {
        $profiles = isset($this->children[$parent]) ? $this->children[$parent] : array();
        $profiles[] = $profile;
        $this->children[$parent] = $profiles;
      }
    }
    if (isset($this->children[$request])) {
      foreach ($this->children[$request] as $child) {
        $profile
          ->addChild($child);
      }
      $this->children[$request] = array();
    }
    if ($master) {
      $this
        ->saveProfiles($profile);
    }
  }
  public static function getSubscribedEvents() {
    return array(
      // kernel.request must be registered as early as possible to not break
      // when an exception is thrown in any other kernel.request listener
      KernelEvents::REQUEST => array(
        'onKernelRequest',
        1024,
      ),
      KernelEvents::RESPONSE => array(
        'onKernelResponse',
        -100,
      ),
      KernelEvents::EXCEPTION => 'onKernelException',
    );
  }

  /**
   * Saves the profile hierarchy.
   *
   * @param Profile $profile The root profile
   */
  private function saveProfiles(Profile $profile) {
    $this->profiler
      ->saveProfile($profile);
    foreach ($profile
      ->getChildren() as $profile) {
      $this
        ->saveProfiles($profile);
    }
  }

}