hybridgroup.gobot/platforms/mavlink/mavlink_udp_adaptor.go

102 lines
1.8 KiB
Go

package mavlink
import (
"net"
common "gobot.io/x/gobot/v2/platforms/mavlink/common"
)
type UDPConnection interface {
Close() error
ReadFromUDP([]byte) (int, *net.UDPAddr, error)
WriteTo([]byte, net.Addr) (int, error)
}
type UDPAdaptor struct {
name string
port string
sock UDPConnection
}
var _ BaseAdaptor = (*UDPAdaptor)(nil)
// NewAdaptor creates a new Mavlink-over-UDP adaptor with specified
// port.
func NewUDPAdaptor(port string) *UDPAdaptor {
return &UDPAdaptor{
name: "Mavlink",
port: port,
}
}
func (m *UDPAdaptor) Name() string { return m.name }
func (m *UDPAdaptor) SetName(n string) { m.name = n }
func (m *UDPAdaptor) Port() string { return m.port }
// Connect returns true if connection to device is successful
func (m *UDPAdaptor) Connect() error {
m.close()
addr, err := net.ResolveUDPAddr("udp", m.Port())
if err != nil {
return err
}
m.sock, err = net.ListenUDP("udp", addr)
if err != nil {
return err
}
return nil
}
func (m *UDPAdaptor) close() error {
sock := m.sock
m.sock = nil
if sock != nil {
return sock.Close()
} else {
return nil
}
}
// Finalize returns true if connection to devices is closed successfully
func (m *UDPAdaptor) Finalize() (err error) {
return m.close()
}
func (m *UDPAdaptor) ReadMAVLinkPacket() (*common.MAVLinkPacket, error) {
buf := make([]byte, 4096)
for {
got, _, err := m.sock.ReadFromUDP(buf)
if err != nil {
return nil, err
}
if got < 2 {
continue
}
sof := buf[0]
length := buf[1]
if sof != common.MAVLINK_10_STX {
continue
}
if length > 250 {
continue
}
m := &common.MAVLinkPacket{}
m.Decode(buf)
return m, nil
}
}
func (m *UDPAdaptor) Write(b []byte) (int, error) {
addr, err := net.ResolveUDPAddr("udp", m.Port())
if err != nil {
return 0, err
}
return m.sock.WriteTo(b, addr)
}