83 lines
2.1 KiB
Go
83 lines
2.1 KiB
Go
package packets
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"github.com/pborman/uuid"
|
|
"io"
|
|
)
|
|
|
|
//PublishPacket is an internal representation of the fields of the
|
|
//Publish MQTT packet
|
|
type PublishPacket struct {
|
|
FixedHeader
|
|
TopicName string
|
|
MessageID uint16
|
|
Payload []byte
|
|
uuid uuid.UUID
|
|
}
|
|
|
|
func (p *PublishPacket) String() string {
|
|
str := fmt.Sprintf("%s\n", p.FixedHeader)
|
|
str += fmt.Sprintf("topicName: %s MessageID: %d\n", p.TopicName, p.MessageID)
|
|
str += fmt.Sprintf("payload: %s\n", string(p.Payload))
|
|
return str
|
|
}
|
|
|
|
func (p *PublishPacket) Write(w io.Writer) error {
|
|
var body bytes.Buffer
|
|
var err error
|
|
|
|
body.Write(encodeString(p.TopicName))
|
|
if p.Qos > 0 {
|
|
body.Write(encodeUint16(p.MessageID))
|
|
}
|
|
p.FixedHeader.RemainingLength = body.Len() + len(p.Payload)
|
|
packet := p.FixedHeader.pack()
|
|
packet.Write(body.Bytes())
|
|
packet.Write(p.Payload)
|
|
_, err = w.Write(packet.Bytes())
|
|
|
|
return err
|
|
}
|
|
|
|
//Unpack decodes the details of a ControlPacket after the fixed
|
|
//header has been read
|
|
func (p *PublishPacket) Unpack(b io.Reader) {
|
|
var payloadLength = p.FixedHeader.RemainingLength
|
|
p.TopicName = decodeString(b)
|
|
if p.Qos > 0 {
|
|
p.MessageID = decodeUint16(b)
|
|
payloadLength -= len(p.TopicName) + 4
|
|
} else {
|
|
payloadLength -= len(p.TopicName) + 2
|
|
}
|
|
p.Payload = make([]byte, payloadLength)
|
|
b.Read(p.Payload)
|
|
}
|
|
|
|
//Copy creates a new PublishPacket with the same topic and payload
|
|
//but an empty fixed header, useful for when you want to deliver
|
|
//a message with different properties such as Qos but the same
|
|
//content
|
|
func (p *PublishPacket) Copy() *PublishPacket {
|
|
newP := NewControlPacket(Publish).(*PublishPacket)
|
|
newP.TopicName = p.TopicName
|
|
newP.Payload = p.Payload
|
|
|
|
return newP
|
|
}
|
|
|
|
//Details returns a Details struct containing the Qos and
|
|
//MessageID of this ControlPacket
|
|
func (p *PublishPacket) Details() Details {
|
|
return Details{Qos: p.Qos, MessageID: p.MessageID}
|
|
}
|
|
|
|
//UUID returns the unique ID assigned to the ControlPacket when
|
|
//it was originally received. Note: this is not related to the
|
|
//MessageID field for MQTT packets
|
|
func (p *PublishPacket) UUID() uuid.UUID {
|
|
return p.uuid
|
|
}
|