// Publish sends a single MQTT PUBLISH message to the server. On completion, the
// supplied OnCompleteFunc is called. For QOS 0 messages, onComplete is called
// immediately after the message is sent to the outgoing buffer. For QOS 1 messages,
// onComplete is called when PUBACK is received. For QOS 2 messages, onComplete is
// called after the PUBCOMP message is received.
func (this *Server) Publish(msg *message.PublishMessage, onComplete OnCompleteFunc) error {
if err := this.checkConfiguration(); err != nil {
return err
}
if msg.Retain() {
if err := this.topicsMgr.Retain(msg); err != nil {
glog.Errorf("Error retaining message: %v", err)
}
}
if err := this.topicsMgr.Subscribers(msg.Topic(), msg.QoS(), &this.subs, &this.qoss); err != nil {
return err
}
msg.SetRetain(false)
//glog.Debugf("(server) Publishing to topic %q and %d subscribers", string(msg.Topic()), len(this.subs))
for _, s := range this.subs {
if s != nil {
fn, ok := s.(*OnPublishFunc)
if !ok {
glog.Errorf("Invalid onPublish Function")
} else {
(*fn)(msg)
}
}
}
return nil
}
// onPublish() is called when the server receives a PUBLISH message AND have completed
// the ack cycle. This method will get the list of subscribers based on the publish
// topic, and publishes the message to the list of subscribers.
func (this *service) onPublish(msg *message.PublishMessage) error {
if msg.Retain() {
if err := this.topicsMgr.Retain(msg); err != nil {
glog.Errorf("(%s) Error retaining message: %v", this.cid(), err)
}
}
err := this.topicsMgr.Subscribers(msg.Topic(), msg.QoS(), &this.subs, &this.qoss)
if err != nil {
glog.Errorf("(%s) Error retrieving subscribers list: %v", this.cid(), err)
return err
}
msg.SetRetain(false)
//glog.Debugf("(%s) Publishing to topic %q and %d subscribers", this.cid(), string(msg.Topic()), len(this.subs))
for _, s := range this.subs {
if s != nil {
fn, ok := s.(*OnPublishFunc)
if !ok {
glog.Errorf("Invalid onPublish Function")
return fmt.Errorf("Invalid onPublish Function")
} else {
(*fn)(msg)
}
}
}
return nil
}
func (this *memTopics) Retain(msg *message.PublishMessage) error {
this.rmu.Lock()
defer this.rmu.Unlock()
// So apparently, at least according to the MQTT Conformance/Interoperability
// Testing, that a payload of 0 means delete the retain message.
// https://eclipse.org/paho/clients/testing/
if len(msg.Payload()) == 0 {
return this.rroot.rremove(msg.Topic())
}
return this.rroot.rinsert(msg.Topic(), msg)
}