// For SUBSCRIBE message, we should add subscriber, then send back SUBACK
func (this *service) processSubscribe(msg *message.SubscribeMessage) error {
resp := message.NewSubackMessage()
resp.SetPacketId(msg.PacketId())
// Subscribe to the different topics
var retcodes []byte
topics := msg.Topics()
qos := msg.Qos()
this.rmsgs = this.rmsgs[0:0]
for i, t := range topics {
rqos, err := this.topicsMgr.Subscribe(t, qos[i], &this.onpub)
if err != nil {
return err
}
this.sess.AddTopic(string(t), qos[i])
retcodes = append(retcodes, rqos)
// yeah I am not checking errors here. If there's an error we don't want the
// subscription to stop, just let it go.
this.topicsMgr.Retained(t, &this.rmsgs)
glog.Debugf("(%s) topic = %s, retained count = %d", this.cid(), string(t), len(this.rmsgs))
}
if err := resp.AddReturnCodes(retcodes); err != nil {
return err
}
if _, err := this.writeMessage(resp); err != nil {
return err
}
for _, rm := range this.rmsgs {
if err := this.publish(rm, nil); err != nil {
glog.Errorf("service/processSubscribe: Error publishing retained message: %v", err)
return err
}
}
return nil
}
func (this *service) subscribe(msg *message.SubscribeMessage, onComplete OnCompleteFunc, onPublish OnPublishFunc) error {
if onPublish == nil {
return fmt.Errorf("onPublish function is nil. No need to subscribe.")
}
_, err := this.writeMessage(msg)
if err != nil {
return fmt.Errorf("(%s) Error sending %s message: %v", this.cid(), msg.Name(), err)
}
var onc OnCompleteFunc = func(msg, ack message.Message, err error) error {
onComplete := onComplete
onPublish := onPublish
if err != nil {
if onComplete != nil {
return onComplete(msg, ack, err)
}
return err
}
sub, ok := msg.(*message.SubscribeMessage)
if !ok {
if onComplete != nil {
return onComplete(msg, ack, fmt.Errorf("Invalid SubscribeMessage received"))
}
return nil
}
suback, ok := ack.(*message.SubackMessage)
if !ok {
if onComplete != nil {
return onComplete(msg, ack, fmt.Errorf("Invalid SubackMessage received"))
}
return nil
}
if sub.PacketId() != suback.PacketId() {
if onComplete != nil {
return onComplete(msg, ack, fmt.Errorf("Sub and Suback packet ID not the same. %d != %d.", sub.PacketId(), suback.PacketId()))
}
return nil
}
retcodes := suback.ReturnCodes()
topics := sub.Topics()
if len(topics) != len(retcodes) {
if onComplete != nil {
return onComplete(msg, ack, fmt.Errorf("Incorrect number of return codes received. Expecting %d, got %d.", len(topics), len(retcodes)))
}
return nil
}
var err2 error = nil
for i, t := range topics {
c := retcodes[i]
if c == message.QosFailure {
err2 = fmt.Errorf("Failed to subscribe to '%s'\n%v", string(t), err2)
} else {
this.sess.AddTopic(string(t), c)
_, err := this.topicsMgr.Subscribe(t, c, &onPublish)
if err != nil {
err2 = fmt.Errorf("Failed to subscribe to '%s' (%v)\n%v", string(t), err, err2)
}
}
}
if onComplete != nil {
return onComplete(msg, ack, err2)
}
return err2
}
return this.sess.Suback.Wait(msg, onc)
}