Files
cms-core/Classes/Middleware/CacheDataCollectorAttribute.php

92 lines
3.7 KiB
PHP

<?php
declare(strict_types=1);
/*
* This file is part of the TYPO3 CMS project.
*
* It is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, either version 2
* of the License, or any later version.
*
* For the full copyright and license information, please read the
* LICENSE.txt file that was distributed with this source code.
*
* The TYPO3 project - inspiring people to share!
*/
namespace TYPO3\CMS\Core\Middleware;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;
use TYPO3\CMS\Core\Attribute\AsEventListener;
use TYPO3\CMS\Core\Cache\CacheDataCollector;
use TYPO3\CMS\Core\Cache\CacheTag;
use TYPO3\CMS\Core\Cache\Event\AddCacheTagEvent;
/**
* Add CacheTags as 'cacheDataCollector' attribute.
*
* @internal
*/
class CacheDataCollectorAttribute implements MiddlewareInterface
{
/**
* The maximum length of the X-TYPO3-Cache-Tags header.
* Prevents exceeding the maximum header size of 8kB.
* Some web servers (e.g. nginx or apache2) have a default
* limit of 8kB for the size of a single header.
*/
private const int MAX_CACHE_TAGS_HEADER_LENGTH = 8000;
private ?CacheDataCollector $cacheDataCollector = null;
/**
* Adds an instance of TYPO3\CMS\Core\Cache\CacheDataCollector as
* attribute to $request object
*/
public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
{
// Middlewares are shared services. With sub requests in mind, we need to take care
// existing data of the parent request is not overwritten by a sub request. We thus
// back up any existing data, create a new CacheDataCollector, dispatch the request,
// and reset before returning the response.
// @todo: We could argue sub requests should run their own container instance, but
// this has more impact and has not been sorted out, yet.
$backup = $this->cacheDataCollector;
$this->cacheDataCollector = new CacheDataCollector();
$request = $request->withAttribute('frontend.cache.collector', $this->cacheDataCollector);
$response = $handler->handle($request);
if ($this->isDebugModeEnabled()) {
$cacheTags = array_map(fn(CacheTag $cacheTag) => $cacheTag->name, $this->cacheDataCollector->getCacheTags());
sort($cacheTags);
foreach (explode("\n", wordwrap(implode(' ', $cacheTags), self::MAX_CACHE_TAGS_HEADER_LENGTH, "\n")) as $delta => $tags) {
$response = $response->withHeader('X-TYPO3-Cache-Tags' . ($delta > 0 ? '-' . $delta : ''), $tags);
}
$response = $response->withHeader('X-TYPO3-Cache-Lifetime', (string)$this->cacheDataCollector->resolveLifetime());
}
foreach ($this->cacheDataCollector->getCacheEntries() as $deferredCacheItem) {
$deferredCacheItem($request);
}
$this->cacheDataCollector = $backup;
return $response;
}
#[AsEventListener]
public function onCacheTagAdded(AddCacheTagEvent $event): void
{
// This event listener is a tribute to code places that want to add cache tags,
// but don't have the request available to set cache tags on the attribute directly.
// TYPO3 core will try to get rid of these places over time, but needs this event
// listener for now.
$this->cacheDataCollector?->addCacheTags($event->cacheTag);
}
private function isDebugModeEnabled(): bool
{
return !empty($GLOBALS['TYPO3_CONF_VARS']['FE']['debug']);
}
}