First implementation

vendor/github.com/eclipse/paho.mqtt.golang/packets/subscribe.go

@@ -0,0 +1,72 @@
+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 {
+	var err error
+	s.MessageID, err = decodeUint16(b)
+	if err != nil {
+		return err
+	}
+	payloadLength := s.FixedHeader.RemainingLength - 2
+	for payloadLength > 0 {
+		topic, err := decodeString(b)
+		if err != nil {
+			return err
+		}
+		s.Topics = append(s.Topics, topic)
+		qos, err := decodeByte(b)
+		if err != nil {
+			return err
+		}
+		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}
+}