Golang appengine_internal-socket.CreateSocketRequest_SocketProtocol类(方法)实例源码

func addr(prot pb.CreateSocketRequest_SocketProtocol, ap *pb.AddressPort) net.Addr {
	if ap == nil {
		return nil
	}
	switch prot {
	case pb.CreateSocketRequest_TCP:
		return &net.TCPAddr{
			IP:   net.IP(ap.PackedAddress),
			Port: int(*ap.Port),
		}
	case pb.CreateSocketRequest_UDP:
		return &net.UDPAddr{
			IP:   net.IP(ap.PackedAddress),
			Port: int(*ap.Port),
		}
	}
	panic("unknown protocol " + prot.String())
}

// DialTimeout is like Dial but takes a timeout.
// The timeout includes name resolution, if required.
func DialTimeout(c appengine.Context, protocol, addr string, timeout time.Duration) (*Conn, error) {
	var deadline time.Time
	if timeout > 0 {
		deadline = time.Now().Add(timeout)
	}

	host, portStr, err := net.SplitHostPort(addr)
	if err != nil {
		return nil, err
	}
	port, err := strconv.Atoi(portStr)
	if err != nil {
		return nil, fmt.Errorf("socket: bad port %q: %v", portStr, err)
	}

	var prot pb.CreateSocketRequest_SocketProtocol
	switch protocol {
	case "tcp":
		prot = pb.CreateSocketRequest_TCP
	case "udp":
		prot = pb.CreateSocketRequest_UDP
	default:
		return nil, fmt.Errorf("socket: unknown protocol %q", protocol)
	}

	packedAddrs, resolved, err := resolve(c, ipFamilies, host, deadline)
	if err != nil {
		return nil, fmt.Errorf("socket: failed resolving %q: %v", host, err)
	}
	if len(packedAddrs) == 0 {
		return nil, fmt.Errorf("no addresses for %q", host)
	}

	packedAddr := packedAddrs[0] // use first address
	fam := pb.CreateSocketRequest_IPv4
	if len(packedAddr) == net.IPv6len {
		fam = pb.CreateSocketRequest_IPv6
	}

	req := &pb.CreateSocketRequest{
		Family:   fam.Enum(),
		Protocol: prot.Enum(),
		RemoteIp: &pb.AddressPort{
			Port:          proto.Int32(int32(port)),
			PackedAddress: packedAddr,
		},
	}
	if resolved {
		req.RemoteIp.HostnameHint = &host
	}
	res := &pb.CreateSocketReply{}
	if err := c.Call("remote_socket", "CreateSocket", req, res, opts(deadline)); err != nil {
		return nil, err
	}

	return &Conn{
		c:      c,
		desc:   res.GetSocketDescriptor(),
		prot:   prot,
		local:  res.ProxyExternalIp,
		remote: req.RemoteIp,
	}, nil
}