<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* This code is partially based on the Rack-Cache library by Ryan Tomayko,
* which is released under the MIT license.
* (based on commit 02d2b48d75bcb63cf1c0c7149c077ad256542801)
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\HttpKernel\HttpCache;
use Symfony\Component\HttpFoundation\Response;
/**
* EsiResponseCacheStrategy knows how to compute the Response cache HTTP header
* based on the different ESI response cache headers.
*
* This implementation changes the master response TTL to the smallest TTL received
* or force validation if one of the ESI has validation cache strategy.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class EsiResponseCacheStrategy implements EsiResponseCacheStrategyInterface {
private $cacheable = true;
private $ttls = array();
private $maxAges = array();
/**
* Adds a Response.
*
* @param Response $response
*/
public function add(Response $response) {
if ($response
->isValidateable()) {
$this->cacheable = false;
}
else {
$this->ttls[] = $response
->getTtl();
$this->maxAges[] = $response
->getMaxAge();
}
}
/**
* Updates the Response HTTP headers based on the embedded Responses.
*
* @param Response $response
*/
public function update(Response $response) {
// if we only have one Response, do nothing
if (1 === count($this->ttls)) {
return;
}
if (!$this->cacheable) {
$response->headers
->set('Cache-Control', 'no-cache, must-revalidate');
return;
}
if (null !== ($maxAge = min($this->maxAges))) {
$response
->setSharedMaxAge($maxAge);
$response->headers
->set('Age', $maxAge - min($this->ttls));
}
$response
->setMaxAge(0);
}
}
Name | Description |
---|---|
EsiResponseCacheStrategy | EsiResponseCacheStrategy knows how to compute the Response cache HTTP header based on the different ESI response cache headers. |