minio/vendor/github.com/eclipse/paho.mqtt.golang/packets/subscribe.go
splinter98 8293f546af Add support for MQTT server as a notification target (#4474)
This implementation is similar to AMQP notifications:

* Notifications are published on a single topic as a JSON feed
* Topic is configurable, as is the QoS. Uses the paho.mqtt.golang
  library for the mqtt connection, and supports connections over tcp
  and websockets, with optional secure tls support.
* Additionally the minio server configuration has been bumped up
  so mqtt configuration can be added.
* Configuration migration code is added with tests.

MQTT is an ISO standard M2M/IoT messaging protocol and was
originally designed for applications for limited bandwidth
networks. Today it's use is growing in the IoT space.
2017-06-14 17:27:49 -07:00

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}
}