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 Symfony\Component\HttpKernel\EventListener;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Attribute\Cache;
use Symfony\Component\HttpKernel\Event\ControllerArgumentsEvent;
use Symfony\Component\HttpKernel\Event\ResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
/**
* Handles HTTP cache headers configured via the Cache attribute.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class CacheAttributeListener implements EventSubscriberInterface
{
/**
* @var \SplObjectStorage<Request, \DateTimeInterface>
*/
private \SplObjectStorage $lastModified;
/**
* @var \SplObjectStorage<Request, string>
*/
private \SplObjectStorage $etags;
public function __construct(
private ?ExpressionLanguage $expressionLanguage = null,
) {
$this->lastModified = new \SplObjectStorage();
$this->etags = new \SplObjectStorage();
}
/**
* Handles HTTP validation headers.
*/
public function onKernelControllerArguments(ControllerArgumentsEvent $event)
{
$request = $event->getRequest();
if (!\is_array($attributes = $request->attributes->get('_cache') ?? $event->getAttributes()[Cache::class] ?? null)) {
return;
}
$request->attributes->set('_cache', $attributes);
$response = null;
$lastModified = null;
$etag = null;
/** @var Cache[] $attributes */
foreach ($attributes as $cache) {
if (null !== $cache->lastModified) {
$lastModified = $this->getExpressionLanguage()->evaluate($cache->lastModified, array_merge($request->attributes->all(), $event->getNamedArguments()));
($response ??= new Response())->setLastModified($lastModified);
}
if (null !== $cache->etag) {
$etag = hash('sha256', $this->getExpressionLanguage()->evaluate($cache->etag, array_merge($request->attributes->all(), $event->getNamedArguments())));
($response ??= new Response())->setEtag($etag);
}
}
if ($response?->isNotModified($request)) {
$event->setController(static fn () => $response);
$event->stopPropagation();
return;
}
if (null !== $etag) {
$this->etags[$request] = $etag;
}
if (null !== $lastModified) {
$this->lastModified[$request] = $lastModified;
}
}
/**
* Modifies the response to apply HTTP cache headers when needed.
*/
public function onKernelResponse(ResponseEvent $event)
{
$request = $event->getRequest();
/** @var Cache[] $attributes */
if (!\is_array($attributes = $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])) {
unset($this->lastModified[$request]);
unset($this->etags[$request]);
return;
}
if (isset($this->lastModified[$request]) && !$response->headers->has('Last-Modified')) {
$response->setLastModified($this->lastModified[$request]);
}
if (isset($this->etags[$request]) && !$response->headers->has('Etag')) {
$response->setEtag($this->etags[$request]);
}
unset($this->lastModified[$request]);
unset($this->etags[$request]);
$hasVary = $response->headers->has('Vary');
foreach (array_reverse($attributes) as $cache) {
if (null !== $cache->smaxage && !$response->headers->hasCacheControlDirective('s-maxage')) {
$response->setSharedMaxAge($this->toSeconds($cache->smaxage));
}
if ($cache->mustRevalidate) {
$response->headers->addCacheControlDirective('must-revalidate');
}
if (null !== $cache->maxage && !$response->headers->hasCacheControlDirective('max-age')) {
$response->setMaxAge($this->toSeconds($cache->maxage));
}
if (null !== $cache->maxStale && !$response->headers->hasCacheControlDirective('max-stale')) {
$response->headers->addCacheControlDirective('max-stale', $this->toSeconds($cache->maxStale));
}
if (null !== $cache->staleWhileRevalidate && !$response->headers->hasCacheControlDirective('stale-while-revalidate')) {
$response->headers->addCacheControlDirective('stale-while-revalidate', $this->toSeconds($cache->staleWhileRevalidate));
}
if (null !== $cache->staleIfError && !$response->headers->hasCacheControlDirective('stale-if-error')) {
$response->headers->addCacheControlDirective('stale-if-error', $this->toSeconds($cache->staleIfError));
}
if (null !== $cache->expires && !$response->headers->has('Expires')) {
$response->setExpires(new \DateTimeImmutable('@'.strtotime($cache->expires, time())));
}
if (!$hasVary && $cache->vary) {
$response->setVary($cache->vary, false);
}
}
foreach ($attributes as $cache) {
if (true === $cache->public) {
$response->setPublic();
}
if (false === $cache->public) {
$response->setPrivate();
}
}
}
public static function getSubscribedEvents(): array
{
return [
KernelEvents::CONTROLLER_ARGUMENTS => ['onKernelControllerArguments', 10],
KernelEvents::RESPONSE => ['onKernelResponse', -10],
];
}
private function getExpressionLanguage(): ExpressionLanguage
{
return $this->expressionLanguage ??= class_exists(ExpressionLanguage::class)
? new ExpressionLanguage()
: throw new \LogicException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed. Try running "composer require symfony/expression-language".');
}
private function toSeconds(int|string $time): int
{
if (!is_numeric($time)) {
$now = time();
$time = strtotime($time, $now) - $now;
}
return $time;
}
}

vendor/symfony/http-kernel/EventListener/CacheAttributeListener.php line 94