Symfony Profiler

<?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 Sensio\Bundle\FrameworkExtraBundle\EventListener;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Event\KernelEvent;
use Symfony\Component\HttpKernel\KernelEvents;
/**
* HttpCacheListener handles HTTP cache headers.
*
* It can be configured via the Cache annotation.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class HttpCacheListener implements EventSubscriberInterface
{
private $lastModifiedDates;
private $etags;
private $expressionLanguage;
public function __construct()
{
$this->lastModifiedDates = new \SplObjectStorage();
$this->etags = new \SplObjectStorage();
}
/**
* Handles HTTP validation headers.
*/
public function onKernelController(KernelEvent $event)
{
$request = $event->getRequest();
if (!$configuration = $request->attributes->get('_cache')) {
return;
}
$response = new Response();
$lastModifiedDate = '';
if ($configuration->getLastModified()) {
$lastModifiedDate = $this->getExpressionLanguage()->evaluate($configuration->getLastModified(), $request->attributes->all());
$response->setLastModified($lastModifiedDate);
}
$etag = '';
if ($configuration->getEtag()) {
$etag = hash('sha256', $this->getExpressionLanguage()->evaluate($configuration->getEtag(), $request->attributes->all()));
$response->setEtag($etag);
}
if ($response->isNotModified($request)) {
$event->setController(function () use ($response) {
return $response;
});
$event->stopPropagation();
} else {
if ($etag) {
$this->etags[$request] = $etag;
}
if ($lastModifiedDate) {
$this->lastModifiedDates[$request] = $lastModifiedDate;
}
}
}
/**
* Modifies the response to apply HTTP cache headers when needed.
*/
public function onKernelResponse(KernelEvent $event)
{
$request = $event->getRequest();
if (!$configuration = $request->attributes->get('_cache')) {
return;
}
$response = $event->getResponse();
// http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-12#section-3.1
if (!\in_array($response->getStatusCode(), [200, 203, 300, 301, 302, 304, 404, 410])) {
return;
}
if (!$response->headers->hasCacheControlDirective('s-maxage') && null !== $age = $configuration->getSMaxAge()) {
$age = $this->convertToSecondsIfNeeded($age);
$response->setSharedMaxAge($age);
}
if ($configuration->mustRevalidate()) {
$response->headers->addCacheControlDirective('must-revalidate');
}
if (!$response->headers->hasCacheControlDirective('max-age') && null !== $age = $configuration->getMaxAge()) {
$age = $this->convertToSecondsIfNeeded($age);
$response->setMaxAge($age);
}
if (!$response->headers->hasCacheControlDirective('max-stale') && null !== $stale = $configuration->getMaxStale()) {
$stale = $this->convertToSecondsIfNeeded($stale);
$response->headers->addCacheControlDirective('max-stale', $stale);
}
if (!$response->headers->hasCacheControlDirective('stale-while-revalidate') && null !== $staleWhileRevalidate = $configuration->getStaleWhileRevalidate()) {
$staleWhileRevalidate = $this->convertToSecondsIfNeeded($staleWhileRevalidate);
$response->headers->addCacheControlDirective('stale-while-revalidate', $staleWhileRevalidate);
}
if (!$response->headers->hasCacheControlDirective('stale-if-error') && null !== $staleIfError = $configuration->getStaleIfError()) {
$staleIfError = $this->convertToSecondsIfNeeded($staleIfError);
$response->headers->addCacheControlDirective('stale-if-error', $staleIfError);
}
if (!$response->headers->has('Expires') && null !== $configuration->getExpires()) {
$date = \DateTime::createFromFormat('U', strtotime($configuration->getExpires()), new \DateTimeZone('UTC'));
$response->setExpires($date);
}
if (!$response->headers->has('Vary') && null !== $configuration->getVary()) {
$response->setVary($configuration->getVary());
}
if ($configuration->isPublic()) {
$response->setPublic();
}
if ($configuration->isPrivate()) {
$response->setPrivate();
}
if (!$response->headers->has('Last-Modified') && isset($this->lastModifiedDates[$request])) {
$response->setLastModified($this->lastModifiedDates[$request]);
unset($this->lastModifiedDates[$request]);
}
if (!$response->headers->has('Etag') && isset($this->etags[$request])) {
$response->setEtag($this->etags[$request]);
unset($this->etags[$request]);
}
}
public static function getSubscribedEvents()
{
return [
KernelEvents::CONTROLLER => 'onKernelController',
KernelEvents::RESPONSE => 'onKernelResponse',
];
}
private function getExpressionLanguage()
{
if (null === $this->expressionLanguage) {
if (!class_exists(ExpressionLanguage::class)) {
throw new \RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
}
$this->expressionLanguage = new ExpressionLanguage();
}
return $this->expressionLanguage;
}
/**
* @param int|string $time Time that can be either expressed in seconds or with relative time format (1 day, 2 weeks, ...)
*
* @return int
*/
private function convertToSecondsIfNeeded($time)
{
if (!is_numeric($time)) {
$now = microtime(true);
$time = ceil(strtotime($time, $now) - $now);
}
return $time;
}
}

vendor/sensio/framework-extra-bundle/src/EventListener/HttpCacheListener.php line 81