63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
package packets
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
//SubscribePacket is an internal representation of the fields of the
|
|
//Subscribe MQTT packet
|
|
type SubscribePacket struct {
|
|
FixedHeader
|
|
MessageID uint16
|
|
Topics []string
|
|
Qoss []byte
|
|
}
|
|
|
|
func (s *SubscribePacket) String() string {
|
|
str := fmt.Sprintf("%s", s.FixedHeader)
|
|
str += " "
|
|
str += fmt.Sprintf("MessageID: %d topics: %s", s.MessageID, s.Topics)
|
|
return str
|
|
}
|
|
|
|
func (s *SubscribePacket) Write(w io.Writer) error {
|
|
var body bytes.Buffer
|
|
var err error
|
|
|
|
body.Write(encodeUint16(s.MessageID))
|
|
for i, topic := range s.Topics {
|
|
body.Write(encodeString(topic))
|
|
body.WriteByte(s.Qoss[i])
|
|
}
|
|
s.FixedHeader.RemainingLength = body.Len()
|
|
packet := s.FixedHeader.pack()
|
|
packet.Write(body.Bytes())
|
|
_, err = packet.WriteTo(w)
|
|
|
|
return err
|
|
}
|
|
|
|
//Unpack decodes the details of a ControlPacket after the fixed
|
|
//header has been read
|
|
func (s *SubscribePacket) Unpack(b io.Reader) error {
|
|
s.MessageID = decodeUint16(b)
|
|
payloadLength := s.FixedHeader.RemainingLength - 2
|
|
for payloadLength > 0 {
|
|
topic := decodeString(b)
|
|
s.Topics = append(s.Topics, topic)
|
|
qos := decodeByte(b)
|
|
s.Qoss = append(s.Qoss, qos)
|
|
payloadLength -= 2 + len(topic) + 1 //2 bytes of string length, plus string, plus 1 byte for Qos
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
//Details returns a Details struct containing the Qos and
|
|
//MessageID of this ControlPacket
|
|
func (s *SubscribePacket) Details() Details {
|
|
return Details{Qos: 1, MessageID: s.MessageID}
|
|
}
|