vendor\symfony\http-kernel\EventListener\CacheAttributeListener.php line 50

  1. <?php
  3. /*
  4.  * This file is part of the Symfony package.
  5.  *
  6.  * (c) Fabien Potencier <fabien@symfony.com>
  7.  *
  8.  * For the full copyright and license information, please view the LICENSE
  9.  * file that was distributed with this source code.
  10.  */
  12. namespace Symfony\Component\HttpKernel\EventListener;
  14. use Symfony\Component\EventDispatcher\EventSubscriberInterface;
  15. use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
  16. use Symfony\Component\HttpFoundation\Request;
  17. use Symfony\Component\HttpFoundation\Response;
  18. use Symfony\Component\HttpKernel\Attribute\Cache;
  19. use Symfony\Component\HttpKernel\Event\ControllerArgumentsEvent;
  20. use Symfony\Component\HttpKernel\Event\ResponseEvent;
  21. use Symfony\Component\HttpKernel\KernelEvents;
  23. /**
  24.  * Handles HTTP cache headers configured via the Cache attribute.
  25.  *
  26.  * @author Fabien Potencier <fabien@symfony.com>
  27.  */
  28. class CacheAttributeListener implements EventSubscriberInterface
  29. {
  30.     /**
  31.      * @var \SplObjectStorage<Request, \DateTimeInterface>
  32.      */
  33.     private \SplObjectStorage $lastModified;
  35.     /**
  36.      * @var \SplObjectStorage<Request, string>
  37.      */
  38.     private \SplObjectStorage $etags;
  40.     public function __construct(
  41.         private ?ExpressionLanguage $expressionLanguage = null,
  42.     ) {
  43.         $this->lastModified = new \SplObjectStorage();
  44.         $this->etags = new \SplObjectStorage();
  45.     }
  47.     /**
  48.      * Handles HTTP validation headers.
  49.      */
  50.     public function onKernelControllerArguments(ControllerArgumentsEvent $event)
  51.     {
  52.         $request = $event->getRequest();
  54.         if (!\is_array($attributes = $request->attributes->get('_cache') ?? $event->getAttributes()[Cache::class] ?? null)) {
  55.             return;
  56.         }
  58.         $request->attributes->set('_cache', $attributes);
  59.         $response = null;
  60.         $lastModified = null;
  61.         $etag = null;
  63.         /** @var Cache[] $attributes */
  64.         foreach ($attributes as $cache) {
  65.             if (null !== $cache->lastModified) {
  66.                 $lastModified = $this->getExpressionLanguage()->evaluate($cache->lastModified, array_merge($request->attributes->all(), $event->getNamedArguments()));
  67.                 ($response ??= new Response())->setLastModified($lastModified);
  68.             }
  70.             if (null !== $cache->etag) {
  71.                 $etag = hash('sha256', $this->getExpressionLanguage()->evaluate($cache->etag, array_merge($request->attributes->all(), $event->getNamedArguments())));
  72.                 ($response ??= new Response())->setEtag($etag);
  73.             }
  74.         }
  76.         if ($response?->isNotModified($request)) {
  77.             $event->setController(static fn () => $response);
  78.             $event->stopPropagation();
  80.             return;
  81.         }
  83.         if (null !== $etag) {
  84.             $this->etags[$request] = $etag;
  85.         }
  86.         if (null !== $lastModified) {
  87.             $this->lastModified[$request] = $lastModified;
  88.         }
  89.     }
  91.     /**
  92.      * Modifies the response to apply HTTP cache headers when needed.
  93.      */
  94.     public function onKernelResponse(ResponseEvent $event)
  95.     {
  96.         $request = $event->getRequest();
  98.         /** @var Cache[] $attributes */
  99.         if (!\is_array($attributes = $request->attributes->get('_cache'))) {
  100.             return;
  101.         }
  102.         $response = $event->getResponse();
  104.         // http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-12#section-3.1
  105.         if (!\in_array($response->getStatusCode(), [200, 203, 300, 301, 302, 304, 404, 410])) {
  106.             unset($this->lastModified[$request]);
  107.             unset($this->etags[$request]);
  109.             return;
  110.         }
  112.         if (isset($this->lastModified[$request]) && !$response->headers->has('Last-Modified')) {
  113.             $response->setLastModified($this->lastModified[$request]);
  114.         }
  116.         if (isset($this->etags[$request]) && !$response->headers->has('Etag')) {
  117.             $response->setEtag($this->etags[$request]);
  118.         }
  120.         unset($this->lastModified[$request]);
  121.         unset($this->etags[$request]);
  122.         $hasVary = $response->headers->has('Vary');
  124.         foreach (array_reverse($attributes) as $cache) {
  125.             if (null !== $cache->smaxage && !$response->headers->hasCacheControlDirective('s-maxage')) {
  126.                 $response->setSharedMaxAge($this->toSeconds($cache->smaxage));
  127.             }
  129.             if ($cache->mustRevalidate) {
  130.                 $response->headers->addCacheControlDirective('must-revalidate');
  131.             }
  133.             if (null !== $cache->maxage && !$response->headers->hasCacheControlDirective('max-age')) {
  134.                 $response->setMaxAge($this->toSeconds($cache->maxage));
  135.             }
  137.             if (null !== $cache->maxStale && !$response->headers->hasCacheControlDirective('max-stale')) {
  138.                 $response->headers->addCacheControlDirective('max-stale', $this->toSeconds($cache->maxStale));
  139.             }
  141.             if (null !== $cache->staleWhileRevalidate && !$response->headers->hasCacheControlDirective('stale-while-revalidate')) {
  142.                 $response->headers->addCacheControlDirective('stale-while-revalidate', $this->toSeconds($cache->staleWhileRevalidate));
  143.             }
  145.             if (null !== $cache->staleIfError && !$response->headers->hasCacheControlDirective('stale-if-error')) {
  146.                 $response->headers->addCacheControlDirective('stale-if-error', $this->toSeconds($cache->staleIfError));
  147.             }
  149.             if (null !== $cache->expires && !$response->headers->has('Expires')) {
  150.                 $response->setExpires(new \DateTimeImmutable('@'.strtotime($cache->expires, time())));
  151.             }
  153.             if (!$hasVary && $cache->vary) {
  154.                 $response->setVary($cache->vary, false);
  155.             }
  156.         }
  158.         foreach ($attributes as $cache) {
  159.             if (true === $cache->public) {
  160.                 $response->setPublic();
  161.             }
  163.             if (false === $cache->public) {
  164.                 $response->setPrivate();
  165.             }
  166.         }
  167.     }
  169.     public static function getSubscribedEvents(): array
  170.     {
  171.         return [
  172.             KernelEvents::CONTROLLER_ARGUMENTS => ['onKernelControllerArguments', 10],
  173.             KernelEvents::RESPONSE => ['onKernelResponse', -10],
  174.         ];
  175.     }
  177.     private function getExpressionLanguage(): ExpressionLanguage
  178.     {
  179.         return $this->expressionLanguage ??= class_exists(ExpressionLanguage::class)
  180.             ? new ExpressionLanguage()
  181.             : throw new \LogicException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed. Try running "composer require symfony/expression-language".');
  182.     }
  184.     private function toSeconds(int|string $time): int
  185.     {
  186.         if (!is_numeric($time)) {
  187.             $now = time();
  188.             $time = strtotime($time, $now) - $now;
  189.         }
  191.         return $time;
  192.     }
  193. }