1<?php
2
3/*
4 * This file is part of the Assetic package, an OpenSky project.
5 *
6 * (c) 2010-2014 OpenSky Project Inc
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12namespace Assetic\Factory\Loader;
13
14use Assetic\Cache\ConfigCache;
15use Assetic\Factory\Resource\IteratorResourceInterface;
16use Assetic\Factory\Resource\ResourceInterface;
17
18/**
19 * Adds a caching layer to a loader.
20 *
21 * A cached formula loader is a composition of a formula loader and a cache.
22 *
23 * @author Kris Wallsmith <kris.wallsmith@gmail.com>
24 */
25class CachedFormulaLoader implements FormulaLoaderInterface
26{
27    private $loader;
28    private $configCache;
29    private $debug;
30
31    /**
32     * Constructor.
33     *
34     * When the loader is in debug mode it will ensure the cached formulae
35     * are fresh before returning them.
36     *
37     * @param FormulaLoaderInterface $loader      A formula loader
38     * @param ConfigCache            $configCache A config cache
39     * @param Boolean                $debug       The debug mode
40     */
41    public function __construct(FormulaLoaderInterface $loader, ConfigCache $configCache, $debug = false)
42    {
43        $this->loader = $loader;
44        $this->configCache = $configCache;
45        $this->debug = $debug;
46    }
47
48    public function load(ResourceInterface $resources)
49    {
50        if (!$resources instanceof IteratorResourceInterface) {
51            $resources = array($resources);
52        }
53
54        $formulae = array();
55
56        foreach ($resources as $resource) {
57            $id = (string) $resource;
58            if (!$this->configCache->has($id) || ($this->debug && !$resource->isFresh($this->configCache->getTimestamp($id)))) {
59                $formulae += $this->loader->load($resource);
60                $this->configCache->set($id, $formulae);
61            } else {
62                $formulae += $this->configCache->get($id);
63            }
64        }
65
66        return $formulae;
67    }
68}
69