Golang Event Examples

Example #1

File: zmq4.go Project: atmosx/log-courier

// Process ZMQ 4.0.x monitor messages
// http://api.zeromq.org/4-0:zmq-socket-monitor
func (t *TransportZmq) processMonitorIn() (ok bool) {
	for {
		// Bring in the messages
	RetryRecv:
		data, err := t.monitor.Recv(zmq.DONTWAIT)
		if err != nil {
			switch err {
			case syscall.EINTR:
				// Try again
				goto RetryRecv
			case syscall.EAGAIN:
				// No more messages
				ok = true
				return
			}

			// Failure
			t.recv_chan <- fmt.Errorf("Monitor zmq.Socket.Recv failure %s", err)
			return
		}

		switch t.event.part {
		case Monitor_Part_Header:
			t.event.event = zmq.Event(binary.LittleEndian.Uint16(data[0:2]))
			t.event.val = int32(binary.LittleEndian.Uint32(data[2:6]))
			t.event.data = ""
		case Monitor_Part_Data:
			t.event.data = string(data)
			t.event.Log()
		default:
			log.Debug("Extraneous data in monitor message. Silently discarding.")
			continue
		}

		more, err := t.monitor.RcvMore()
		if err != nil {
			// Failure
			t.recv_chan <- fmt.Errorf("Monitor zmq.Socket.RcvMore failure %s", err)
			return
		}

		if !more {
			if t.event.part < Monitor_Part_Data {
				t.event.Log()
				log.Debug("Unexpected end of monitor message. Skipping.")
			}

			t.event.part = Monitor_Part_Header
			continue
		}

		if t.event.part <= Monitor_Part_Data {
			t.event.part++
		}
	}
}

Example #2

File: zmq3.go Project: atmosx/log-courier

// Process ZMQ 3.2.x monitor messages
// http://api.zeromq.org/3-2:zmq-socket-monitor
func (t *TransportZmq) processMonitorIn() (ok bool) {
	for {
		// Bring in the messages
	RetryRecv:
		data, err := t.monitor.Recv(zmq.DONTWAIT)
		if err != nil {
			switch err {
			case syscall.EINTR:
				// Try again
				goto RetryRecv
			case syscall.EAGAIN:
				// No more messages
				ok = true
				return
			}

			// Failure
			t.recv_chan <- fmt.Errorf("Monitor zmq.Socket.Recv failure %s", err)
			return
		}

		switch t.event.part {
		case Monitor_Part_Header:
			event := (*C.struct_zmq_event_t_wrap)(unsafe.Pointer(&data[0]))
			t.event.event = zmq.Event(event.event)
			if event.addr == nil {
				t.event.data = ""
			} else {
				// TODO: Fix this - data has been feed by zmq_msg_close!
				//t.event.data = C.GoString(event.addr)
				t.event.data = ""
			}
			t.event.val = int32(event.fd)
			t.event.Log()
		default:
			log.Debug("Extraneous data in monitor message. Silently discarding.")
			continue
		}

		more, err := t.monitor.RcvMore()
		if err != nil {
			// Failure
			t.recv_chan <- fmt.Errorf("Monitor zmq.Socket.RcvMore failure %s", err)
			return
		}

		if !more {
			t.event.part = Monitor_Part_Header
			continue
		}

		if t.event.part <= Monitor_Part_Data {
			t.event.part++
		}
	}
}