Golang ClientV2.IsReadyForMessages方法代碼示例

func (p *protocolV2) messagePump(client *nsqd.ClientV2, startedChan chan bool,
	stoppedChan chan bool) {
	var err error
	var buf bytes.Buffer
	var clientMsgChan chan *nsqd.Message
	var subChannel *nsqd.Channel
	// NOTE: `flusherChan` is used to bound message latency for
	// the pathological case of a channel on a low volume topic
	// with >1 clients having >1 RDY counts
	var flusherChan <-chan time.Time
	var sampleRate int32

	subEventChan := client.SubEventChan
	identifyEventChan := client.IdentifyEventChan
	outputBufferTicker := time.NewTicker(client.OutputBufferTimeout)
	heartbeatTicker := time.NewTicker(client.HeartbeatInterval)
	heartbeatChan := heartbeatTicker.C
	heartbeatFailedCnt := 0
	msgTimeout := client.MsgTimeout

	// v2 opportunistically buffers data to clients to reduce write system calls
	// we force flush in two cases:
	//    1. when the client is not ready to receive messages
	//    2. we're buffered and the channel has nothing left to send us
	//       (ie. we would block in this loop anyway)
	//
	flushed := true

	// signal to the goroutine that started the messagePump
	// that we've started up
	close(startedChan)

	for {
		if subChannel == nil || !client.IsReadyForMessages() {
			// the client is not ready to receive messages...
			clientMsgChan = nil
			flusherChan = nil
			// force flush
			client.LockWrite()
			err = client.Flush()
			client.UnlockWrite()
			if err != nil {
				goto exit
			}
			flushed = true
		} else if flushed {
			// last iteration we flushed...
			// do not select on the flusher ticker channel
			clientMsgChan = subChannel.GetClientMsgChan()
			flusherChan = nil
		} else {
			// we're buffered (if there isn't any more data we should flush)...
			// select on the flusher ticker channel, too
			clientMsgChan = subChannel.GetClientMsgChan()
			flusherChan = outputBufferTicker.C
		}

		select {
		case <-client.ExitChan:
			goto exit
		case <-flusherChan:
			// if this case wins, we're either starved
			// or we won the race between other channels...
			// in either case, force flush
			client.LockWrite()
			err = client.Flush()
			client.UnlockWrite()
			if err != nil {
				goto exit
			}
			flushed = true
		case <-client.ReadyStateChan:
		case subChannel = <-subEventChan:
			// you can't SUB anymore
			nsqd.NsqLogger().Logf("client %v sub to channel: %v", client.ID,
				subChannel.GetName())
			subEventChan = nil
		case identifyData := <-identifyEventChan:
			// you can't IDENTIFY anymore
			identifyEventChan = nil

			outputBufferTicker.Stop()
			if identifyData.OutputBufferTimeout > 0 {
				outputBufferTicker = time.NewTicker(identifyData.OutputBufferTimeout)
			}

			heartbeatTicker.Stop()
			heartbeatChan = nil
			if identifyData.HeartbeatInterval > 0 {
				heartbeatTicker = time.NewTicker(identifyData.HeartbeatInterval)
				heartbeatChan = heartbeatTicker.C
			}

			if identifyData.SampleRate > 0 {
				sampleRate = identifyData.SampleRate
			}

			msgTimeout = identifyData.MsgTimeout
		case <-heartbeatChan:
			if subChannel != nil && client.IsReadyForMessages() {
//.........這裏部分代碼省略.........