// Internal method to publish a message. func (g *Gilmour) publish(topic string, msg *Message) error { if msg.GetCode() == 0 { msg.SetCode(200) } if msg.GetCode() >= 300 { go func() { request, err := msg.Marshal() if err != nil { request = []byte{} } g.reportError( proto.MakeError( msg.GetCode(), topic, string(request), "", msg.GetSender(), "", ), ) }() } sent, err := g.backend.Publish(topic, msg) if err != nil { return err } else if !sent { return errors.New(fmt.Sprintf("Mesage for %v was not received by anyone.", topic)) } else { return err } }
func (g *Gilmour) handleRequest(s *Subscription, topic string, m *Message) { senderId := m.GetSender() req := &Request{topic, m} res := NewMessage() res.setSender(proto.ResponseTopic(senderId)) done := make(chan bool, 1) //Executing Request go func(done chan<- bool) { // Schedule a function to recover in case handler runs into an error. // Read more: https://gist.github.com/meson10/d56eface6f87c664d07d defer func() { err := recover() if err == nil { return } const size = 4096 buf := make([]byte, size) buf = buf[:runtime.Stack(buf, false)] buffer := string(buf) res.SetData(buffer).SetCode(500) done <- true }() s.GetHandler()(req, res) done <- true }(done) // Start a timeout handler, which writes on the Done channel, ahead of the // handler. This might result in a RACE condition, as there is no way to // kill a goroutine, since they are not preemptive. timeout := s.GetOpts().GetTimeout() time.AfterFunc(time.Duration(timeout)*time.Second, func() { done <- false }) status := <-done if s.GetOpts().shouldSendResponse() { if status == false { g.sendTimeout(senderId, res.GetSender()) } else { if res.GetCode() == 0 { res.SetCode(200) } if err := g.publish(res.GetSender(), res); err != nil { ui.Alert(err.Error()) } } } else if status == false { // Inform the error catcher, If there is no handler for this Request // but the request had failed. This is automatically handled in case // of a response being written via Publisher. request := string(req.bytes()) errMsg := proto.MakeError(499, topic, request, "", req.Sender(), "") g.reportError(errMsg) } }