ProfilerSubscriber.php

<?php

namespace Drupal\webprofiler\EventSubscriber;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
use Symfony\Component\HttpKernel\Event\FinishRequestEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Profiler\Profiler;
use Symfony\Component\HttpFoundation\RequestMatcherInterface;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
class ProfilerSubscriber implements EventSubscriberInterface {
    protected $profiler;
    protected $matcher;
    protected $onlyException;
    protected $onlyMasterRequests;
    protected $exception;
    protected $profiles;
    protected $requestStack;
    protected $parents;
    
    /**
     * @param Profiler $profiler A Profiler instance
     * @param RequestStack $requestStack A RequestStack instance
     * @param RequestMatcherInterface|null $matcher A RequestMatcher instance
     * @param bool $onlyException True if the profiler only collects data when an
     *   exception occurs, false otherwise
     * @param bool $onlyMasterRequests True if the profiler only collects data
     *   when the request is a master request, false otherwise
     */
    public function __construct(Profiler $profiler, RequestStack $requestStack, RequestMatcherInterface $matcher = NULL, $onlyException = FALSE, $onlyMasterRequests = FALSE) {
        $this->profiler = $profiler;
        $this->matcher = $matcher;
        $this->onlyException = (bool) $onlyException;
        $this->onlyMasterRequests = (bool) $onlyMasterRequests;
        $this->profiles = new \SplObjectStorage();
        $this->parents = new \SplObjectStorage();
        $this->requestStack = $requestStack;
    }
    
    /**
     * Handles the onKernelException event.
     */
    public function onKernelException(GetResponseForExceptionEvent $event) {
        if ($this->onlyMasterRequests && !$event->isMasterRequest()) {
            return;
        }
        $this->exception = $event->getException();
    }
    
    /**
     * Handles the onKernelResponse event.
     */
    public function onKernelResponse(FilterResponseEvent $event) {
        $master = $event->isMasterRequest();
        if ($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;
        }
        $this->profiles[$request] = $profile;
        $this->parents[$request] = $this->requestStack
            ->getParentRequest();
    }
    public function onKernelFinishRequest(FinishRequestEvent $event) {
        // attach children to parents
        foreach ($this->profiles as $request) {
            if (NULL !== ($parentRequest = $this->parents[$request])) {
                if (isset($this->profiles[$parentRequest])) {
                    $this->profiles[$parentRequest]
                        ->addChild($this->profiles[$request]);
                }
            }
        }
        // save profiles
        foreach ($this->profiles as $request) {
            $this->profiler
                ->saveProfile($this->profiles[$request]);
        }
        $this->profiles = new \SplObjectStorage();
        $this->parents = new \SplObjectStorage();
    }
    public static function getSubscribedEvents() {
        return [
            KernelEvents::RESPONSE => [
                'onKernelResponse',
                -100,
            ],
            KernelEvents::EXCEPTION => 'onKernelException',
            KernelEvents::FINISH_REQUEST => [
                'onKernelFinishRequest',
                -1024,
            ],
        ];
    }

}