Req/Resp for Gps

gps_map

func (s *session) Send(req listener.CmdRequest) listener.CmdResponse {
	bytes := req.Bytes()
	_, err := s.conn.Write(bytes)

	if err != nil {
		return listener.CmdResponse{}
	}

	p := packet{bytes}
	s.addCMD(p.command())
	res := <-s.response

	return listener.CmdResponse{Data: res}
}

func (s *session) Close() error {
	return s.conn.Close()
}

func (s *session) addCMD(id uint16) {
	s.Lock()
	defer s.Unlock()

	if cmds, ok := s.pending[id]; ok {
		cmds = append(cmds, id)
		s.pending[id] = cmds
	} else {
		s.pending[id] = []uint16{id}
	}
}

func (s *session) removeCMD(id uint16) {
	s.Lock()
	defer s.Unlock()

	if cmds, ok := s.pending[id]; ok {
		cmdLen := len(s.pending[id])
		if cmdLen > 0 {
			c := make([]uint16, cmdLen-1)
			copy(c, cmds[0:cmdLen-1])
			s.pending[id] = c
		}

		if len(s.pending[id]) == 0 {
			delete(s.pending, id)
		}
	}
}