239 lines
9.1 KiB
PHP
239 lines
9.1 KiB
PHP
|
<?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\HttpCache;
|
||
|
|
|
||
|
|
use Symfony\Component\HttpFoundation\Response;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ResponseCacheStrategy knows how to compute the Response cache HTTP header
|
||
|
|
* based on the different response cache headers.
|
||
|
|
*
|
||
|
|
* This implementation changes the main response TTL to the smallest TTL received
|
||
|
|
* or force validation if one of the surrogates has validation cache strategy.
|
||
|
|
*
|
||
|
|
* @author Fabien Potencier <fabien@symfony.com>
|
||
|
|
*/
|
||
|
|
class ResponseCacheStrategy implements ResponseCacheStrategyInterface
|
||
|
|
{
|
||
|
|
/**
|
||
|
|
* Cache-Control headers that are sent to the final response if they appear in ANY of the responses.
|
||
|
|
*/
|
||
|
|
private const OVERRIDE_DIRECTIVES = ['private', 'no-cache', 'no-store', 'no-transform', 'must-revalidate', 'proxy-revalidate'];
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Cache-Control headers that are sent to the final response if they appear in ALL of the responses.
|
||
|
|
*/
|
||
|
|
private const INHERIT_DIRECTIVES = ['public', 'immutable'];
|
||
|
|
|
||
|
|
private int $embeddedResponses = 0;
|
||
|
|
private bool $isNotCacheableResponseEmbedded = false;
|
||
|
|
private int $age = 0;
|
||
|
|
private \DateTimeInterface|null|false $lastModified = null;
|
||
|
|
private array $flagDirectives = [
|
||
|
|
'no-cache' => null,
|
||
|
|
'no-store' => null,
|
||
|
|
'no-transform' => null,
|
||
|
|
'must-revalidate' => null,
|
||
|
|
'proxy-revalidate' => null,
|
||
|
|
'public' => null,
|
||
|
|
'private' => null,
|
||
|
|
'immutable' => null,
|
||
|
|
];
|
||
|
|
private array $ageDirectives = [
|
||
|
|
'max-age' => null,
|
||
|
|
's-maxage' => null,
|
||
|
|
'expires' => null,
|
||
|
|
];
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @return void
|
||
|
|
*/
|
||
|
|
public function add(Response $response)
|
||
|
|
{
|
||
|
|
++$this->embeddedResponses;
|
||
|
|
|
||
|
|
foreach (self::OVERRIDE_DIRECTIVES as $directive) {
|
||
|
|
if ($response->headers->hasCacheControlDirective($directive)) {
|
||
|
|
$this->flagDirectives[$directive] = true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
foreach (self::INHERIT_DIRECTIVES as $directive) {
|
||
|
|
if (false !== $this->flagDirectives[$directive]) {
|
||
|
|
$this->flagDirectives[$directive] = $response->headers->hasCacheControlDirective($directive);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
$age = $response->getAge();
|
||
|
|
$this->age = max($this->age, $age);
|
||
|
|
|
||
|
|
if ($this->willMakeFinalResponseUncacheable($response)) {
|
||
|
|
$this->isNotCacheableResponseEmbedded = true;
|
||
|
|
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
$isHeuristicallyCacheable = $response->headers->hasCacheControlDirective('public');
|
||
|
|
$maxAge = $response->headers->hasCacheControlDirective('max-age') ? (int) $response->headers->getCacheControlDirective('max-age') : null;
|
||
|
|
$this->storeRelativeAgeDirective('max-age', $maxAge, $age, $isHeuristicallyCacheable);
|
||
|
|
$sharedMaxAge = $response->headers->hasCacheControlDirective('s-maxage') ? (int) $response->headers->getCacheControlDirective('s-maxage') : $maxAge;
|
||
|
|
$this->storeRelativeAgeDirective('s-maxage', $sharedMaxAge, $age, $isHeuristicallyCacheable);
|
||
|
|
|
||
|
|
$expires = $response->getExpires();
|
||
|
|
$expires = null !== $expires ? (int) $expires->format('U') - (int) $response->getDate()->format('U') : null;
|
||
|
|
$this->storeRelativeAgeDirective('expires', $expires >= 0 ? $expires : null, 0, $isHeuristicallyCacheable);
|
||
|
|
|
||
|
|
if (false !== $this->lastModified) {
|
||
|
|
$lastModified = $response->getLastModified();
|
||
|
|
$this->lastModified = $lastModified ? max($this->lastModified, $lastModified) : false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @return void
|
||
|
|
*/
|
||
|
|
public function update(Response $response)
|
||
|
|
{
|
||
|
|
// if we have no embedded Response, do nothing
|
||
|
|
if (0 === $this->embeddedResponses) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Remove Etag since it cannot be merged from embedded responses.
|
||
|
|
$response->setEtag(null);
|
||
|
|
|
||
|
|
$this->add($response);
|
||
|
|
|
||
|
|
$response->headers->set('Age', $this->age);
|
||
|
|
|
||
|
|
if ($this->isNotCacheableResponseEmbedded) {
|
||
|
|
$response->setLastModified(null);
|
||
|
|
|
||
|
|
if ($this->flagDirectives['no-store']) {
|
||
|
|
$response->headers->set('Cache-Control', 'no-cache, no-store, must-revalidate');
|
||
|
|
} else {
|
||
|
|
$response->headers->set('Cache-Control', 'no-cache, must-revalidate');
|
||
|
|
}
|
||
|
|
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
$response->setLastModified($this->lastModified ?: null);
|
||
|
|
|
||
|
|
$flags = array_filter($this->flagDirectives);
|
||
|
|
|
||
|
|
if (isset($flags['must-revalidate'])) {
|
||
|
|
$flags['no-cache'] = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
$response->headers->set('Cache-Control', implode(', ', array_keys($flags)));
|
||
|
|
|
||
|
|
$maxAge = null;
|
||
|
|
|
||
|
|
if (is_numeric($this->ageDirectives['max-age'])) {
|
||
|
|
$maxAge = $this->ageDirectives['max-age'] + $this->age;
|
||
|
|
$response->headers->addCacheControlDirective('max-age', $maxAge);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (is_numeric($this->ageDirectives['s-maxage'])) {
|
||
|
|
$sMaxage = $this->ageDirectives['s-maxage'] + $this->age;
|
||
|
|
|
||
|
|
if ($maxAge !== $sMaxage) {
|
||
|
|
$response->headers->addCacheControlDirective('s-maxage', $sMaxage);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (is_numeric($this->ageDirectives['expires'])) {
|
||
|
|
$date = clone $response->getDate();
|
||
|
|
$date = $date->modify('+'.($this->ageDirectives['expires'] + $this->age).' seconds');
|
||
|
|
$response->setExpires($date);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* RFC2616, Section 13.4.
|
||
|
|
*
|
||
|
|
* @see https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.4
|
||
|
|
*/
|
||
|
|
private function willMakeFinalResponseUncacheable(Response $response): bool
|
||
|
|
{
|
||
|
|
// RFC2616: A response received with a status code of 200, 203, 300, 301 or 410
|
||
|
|
// MAY be stored by a cache […] unless a cache-control directive prohibits caching.
|
||
|
|
if ($response->headers->hasCacheControlDirective('no-cache')
|
||
|
|
|| $response->headers->hasCacheControlDirective('no-store')
|
||
|
|
) {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Etag headers cannot be merged, they render the response uncacheable
|
||
|
|
// by default (except if the response also has max-age etc.).
|
||
|
|
if (null === $response->getEtag() && \in_array($response->getStatusCode(), [200, 203, 300, 301, 410])) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
// RFC2616: A response received with any other status code (e.g. status codes 302 and 307)
|
||
|
|
// MUST NOT be returned in a reply to a subsequent request unless there are
|
||
|
|
// cache-control directives or another header(s) that explicitly allow it.
|
||
|
|
$cacheControl = ['max-age', 's-maxage', 'must-revalidate', 'proxy-revalidate', 'public', 'private'];
|
||
|
|
foreach ($cacheControl as $key) {
|
||
|
|
if ($response->headers->hasCacheControlDirective($key)) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ($response->headers->has('Expires')) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Store lowest max-age/s-maxage/expires for the final response.
|
||
|
|
*
|
||
|
|
* The response might have been stored in cache a while ago. To keep things comparable,
|
||
|
|
* we have to subtract the age so that the value is normalized for an age of 0.
|
||
|
|
*
|
||
|
|
* If the value is lower than the currently stored value, we update the value, to keep a rolling
|
||
|
|
* minimal value of each instruction.
|
||
|
|
*
|
||
|
|
* If the value is NULL and the isHeuristicallyCacheable parameter is false, the directive will
|
||
|
|
* not be set on the final response. In this case, not all responses had the directive set and no
|
||
|
|
* value can be found that satisfies the requirements of all responses. The directive will be dropped
|
||
|
|
* from the final response.
|
||
|
|
*
|
||
|
|
* If the isHeuristicallyCacheable parameter is true, however, the current response has been marked
|
||
|
|
* as cacheable in a public (shared) cache, but did not provide an explicit lifetime that would serve
|
||
|
|
* as an upper bound. In this case, we can proceed and possibly keep the directive on the final response.
|
||
|
|
*/
|
||
|
|
private function storeRelativeAgeDirective(string $directive, ?int $value, int $age, bool $isHeuristicallyCacheable): void
|
||
|
|
{
|
||
|
|
if (null === $value) {
|
||
|
|
if ($isHeuristicallyCacheable) {
|
||
|
|
/*
|
||
|
|
* See https://datatracker.ietf.org/doc/html/rfc7234#section-4.2.2
|
||
|
|
* This particular response does not require maximum lifetime; heuristics might be applied.
|
||
|
|
* Other responses, however, might have more stringent requirements on maximum lifetime.
|
||
|
|
* So, return early here so that the final response can have the more limiting value set.
|
||
|
|
*/
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
$this->ageDirectives[$directive] = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (false !== $this->ageDirectives[$directive]) {
|
||
|
|
$value -= $age;
|
||
|
|
$this->ageDirectives[$directive] = null !== $this->ageDirectives[$directive] ? min($this->ageDirectives[$directive], $value) : $value;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|