DoraRPC\Packet::packDecode PHP Method

    public static function packDecode($str)
    {
        $header = substr($str, 0, 4);
        $len = unpack("Nlen", $header);
        $len = $len["len"];
        if (DoraConst::SW_DATASIGEN_FLAG == true) {
            $signedcode = substr($str, 4, 4);
            $result = substr($str, 8);
            //check signed
            if (pack("N", crc32($result . DoraConst::SW_DATASIGEN_SALT)) != $signedcode) {
                return self::packFormat("Signed check error!", 100005);
            }
            $len = $len - 4;
        } else {
            $result = substr($str, 4);
        }
        if ($len != strlen($result)) {
            //结果长度不对
            echo "error length...\n";
            return self::packFormat("packet length invalid 包长度非法", 100007);
        }
        //if compress the packet
        if (DoraConst::SW_DATACOMPRESS_FLAG == true) {
            $result = gzdecode($result);
        }
        $result = unserialize($result);
        return self::packFormat("OK", 0, $result);
    }