/**
* Enable cache. If $cache is file:/path/cache/file.ser load
* serialized cache file ( { file_path1 = [md5, size, since], ... }).
*
* @throws
* @param string $cache
*/
public function useCache($cache)
{
if (count($this->cache) > 0) {
throw new Exception('cache was already loaded');
}
if (mb_substr($cache, 0, 5) === 'file:') {
$this->conf['use_cache'] = $cache;
$this->cache = [];
$cache_file = mb_substr($cache, 5);
if ($cache_file && File::exists($cache_file)) {
$this->cache = File::unserialize($cache_file);
}
} else {
throw new Exception('invalid cache', $cache);
}
}
