ChainCache.php

<?php


/*
 * This file is part of Twig.
 *
 * (c) Fabien Potencier
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Twig\Cache;


/**
 * Chains several caches together.
 *
 * Cached items are fetched from the first cache having them in its data store.
 * They are saved and deleted in all adapters at once.
 *
 * @author Quentin Devos <quentin@devos.pm>
 */
final class ChainCache implements CacheInterface, RemovableCacheInterface {
    
    /**
     * @param iterable<CacheInterface> $caches The ordered list of caches used to store and fetch cached items
     */
    public function __construct(iterable $caches) {
    }
    public function generateKey(string $name, string $className) : string {
        return $className . '#' . $name;
    }
    public function write(string $key, string $content) : void {
        $splitKey = $this->splitKey($key);
        foreach ($this->caches as $cache) {
            $cache->write($cache->generateKey(...$splitKey), $content);
        }
    }
    public function load(string $key) : void {
        [
            $name,
            $className,
        ] = $this->splitKey($key);
        foreach ($this->caches as $cache) {
            $cache->load($cache->generateKey($name, $className));
            if (class_exists($className, false)) {
                break;
            }
        }
    }
    public function getTimestamp(string $key) : int {
        $splitKey = $this->splitKey($key);
        foreach ($this->caches as $cache) {
            if (0 < ($timestamp = $cache->getTimestamp($cache->generateKey(...$splitKey)))) {
                return $timestamp;
            }
        }
        return 0;
    }
    public function remove(string $name, string $cls) : void {
        foreach ($this->caches as $cache) {
            if ($cache instanceof RemovableCacheInterface) {
                $cache->remove($name, $cls);
            }
        }
    }
    
    /**
     * @return string[]
     */
    private function splitKey(string $key) : array {
        return array_reverse(explode('#', $key, 2));
    }

}