MessagePack\Packer::packInt PHP Метод

    public function packInt($num)
    {
        if ($num >= 0) {
            if ($num <= 0x7f) {
                return \chr($num);
            }
            if ($num <= 0xff) {
                return "Ì" . \chr($num);
            }
            if ($num <= 0xffff) {
                return "Í" . \chr($num >> 8) . \chr($num);
            }
            if ($num <= 4294967295.0) {
                return \pack('CN', 0xce, $num);
            }
            return self::packUint64(0xcf, $num);
        }
        if ($num >= -0x20) {
            return \chr(0xe0 | $num);
        }
        if ($num >= -0x80) {
            return "Ð" . \chr($num);
        }
        if ($num >= -0x8000) {
            return "Ñ" . \chr($num >> 8) . \chr($num);
        }
        if ($num >= -2147483648.0) {
            return \pack('CN', 0xd2, $num);
        }
        return self::packUint64(0xd3, $num);
    }