rss-bridge/caches/FileCache.php

<?php
/**
* Cache with file system
*/
class FileCache implements CacheInterface
{
    protected $path;
    protected $param;

    public function loadData()
    {
        return json_decode(file_get_contents($this->getCacheFile()), true);
    }

    public function saveData($datas)
    {
        $writeStream = file_put_contents($this->getCacheFile(), json_encode($datas, JSON_PRETTY_PRINT));

        if ($writeStream === false) {
            throw new \Exception("Cannot write the cache... Do you have the right permissions ?");
        }

        return $this;
    }

    public function getTime()
    {
        $cacheFile = $this->getCacheFile();
        if (file_exists($cacheFile)) {
            return filemtime($cacheFile);
        }

        return false;
    }

    public function purgeCache($duration)
    {
        $cachePath = $this->getPath();
        if (file_exists($cachePath)) {
            $cacheIterator = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($cachePath),
            RecursiveIteratorIterator::CHILD_FIRST
            );

            foreach ($cacheIterator as $cacheFile) {
                if (in_array($cacheFile->getBasename(), array('.', '..'))) {
                    continue;
                } elseif ($cacheFile->isFile()) {
                    if (filemtime($cacheFile->getPathname()) < time() - $duration) {
                        unlink($cacheFile->getPathname());
                    }
                }
            }
        }
    }

    /**
    * Set cache path
    * @return self
    */
    public function setPath($path)
    {
        if (is_null($path) || !is_string($path)) {
            throw new \Exception('The given path is invalid!');
        }

        $this->path = $path;

        // Make sure path ends with '/' or '\'
        $lastchar = substr($this->path, -1, 1);
        if ($lastchar !== '/' && $lastchar !== '\\') {
            $this->path .= '/';
        }

        if (!is_dir($this->path)) {
            mkdir($this->path, 0755, true);
        }

        return $this;
    }

    /**
    * Set HTTP GET parameters
    * @return self
    */
    public function setParameters(array $param)
    {
        $this->param = array_map('strtolower', $param);

        return $this;
    }

    /**
    * Return cache path (and create if not exist)
    * @return string Cache path
    */
    protected function getPath()
    {
        if (is_null($this->path)) {
            throw new \Exception('Call "setPath" first!');
        }

        return $this->path;
    }

    /**
    * Get the file name use for cache store
    * @return string Path to the file cache
    */
    protected function getCacheFile()
    {
        return $this->getPath() . $this->getCacheName();
    }

    /**
    * Determines file name for store the cache
    * return string
    */
    protected function getCacheName()
    {
        if (is_null($this->param)) {
            throw new \Exception('Call "setParameters" first!');
        }

        return hash('md5', http_build_query($this->param)) . '.cache';
    }
}