/**
* @param string $cache_dir
* @param int $cache_time seconds (0, cache never expires)
*/
public function __construct($cache_dir = '', $cache_time = 0)
{
parent::__construct();
$this->cache_time = (int) $cache_time;
$cache_dir = rtrim($cache_dir, '/') . '/';
if (is_writable($cache_dir)) {
$this->cache_dir = $cache_dir;
} else {
throw new \Exception('Not writable cache_dir: ' . $cache_dir);
}
}
