App\services\Storage::getFileNum PHP Method

    public static function getFileNum($dir, $file_num = 0)
    {
        $resource = opendir($dir);
        while ($filename = readdir($resource)) {
            if ($filename != "." && $filename != "..") {
                $path = "{$dir}/{$filename}";
                if (is_dir($path)) {
                    // recursion
                    $file_num = self::getFileNum($path, $file_num);
                } else {
                    $file_num++;
                }
            }
        }
        closedir($resource);
        return $file_num;
    }