Golang FilterRunner.UsesBuffering方法代碼示例

func (this *SandboxFilter) Run(fr pipeline.FilterRunner, h pipeline.PluginHelper) (err error) {
	inChan := fr.InChan()
	ticker := fr.Ticker()

	var (
		ok             = true
		terminated     = false
		sample         = true
		blocking       = false
		backpressure   = false
		pack           *pipeline.PipelinePack
		retval         int
		msgLoopCount   uint
		injectionCount uint
		startTime      time.Time
		slowDuration   int64 = int64(this.pConfig.Globals.MaxMsgProcessDuration)
		duration       int64
		samplesNeeded  int64
	)

	if fr.UsesBuffering() {
		samplesNeeded = int64(h.PipelineConfig().Globals.PluginChanSize) - 1
	} else {
		samplesNeeded = int64(cap(inChan)) - 1
	}
	// We assign to the return value of Run() for errors in the closure so that
	// the plugin runner can determine what caused the SandboxFilter to return.
	this.sb.InjectMessage(func(payload, payload_type, payload_name string) int {
		if injectionCount == 0 {
			err = pipeline.TerminatedError("exceeded InjectMessage count")
			return 2
		}
		injectionCount--
		pack, e := h.PipelinePack(msgLoopCount)
		if e != nil {
			err = pipeline.TerminatedError(e.Error())
			if e == pipeline.AbortError {
				return 5
			} else {
				return 3
			}
		}
		if len(payload_type) == 0 { // heka protobuf message
			hostname := pack.Message.GetHostname()
			err := proto.Unmarshal([]byte(payload), pack.Message)
			if err == nil {
				// do not allow filters to override the following
				pack.Message.SetType("heka.sandbox." + pack.Message.GetType())
				pack.Message.SetLogger(fr.Name())
				pack.Message.SetHostname(hostname)
			} else {
				return 1
			}
		} else {
			pack.Message.SetType("heka.sandbox-output")
			pack.Message.SetLogger(fr.Name())
			pack.Message.SetPayload(payload)
			ptype, _ := message.NewField("payload_type", payload_type, "file-extension")
			pack.Message.AddField(ptype)
			pname, _ := message.NewField("payload_name", payload_name, "")
			pack.Message.AddField(pname)
		}
		if !fr.Inject(pack) {
			return 4
		}
		atomic.AddInt64(&this.injectMessageCount, 1)
		return 0
	})

	for ok {
		select {
		case pack, ok = <-inChan:
			if !ok {
				break
			}
			atomic.AddInt64(&this.processMessageCount, 1)
			injectionCount = this.pConfig.Globals.MaxMsgProcessInject
			msgLoopCount = pack.MsgLoopCount

			if this.manager != nil { // only check for backpressure on dynamic plugins
				backpressure = fr.BackPressured()
			}

			// performing the timing is expensive ~40ns but if we are
			// backpressured we need a decent sample set before triggering
			// termination
			if sample ||
				(backpressure && this.processMessageSamples < samplesNeeded) ||
				this.sbc.Profile {
				startTime = time.Now()
				sample = true
			}
			retval = this.sb.ProcessMessage(pack)
			if sample {
				duration = time.Since(startTime).Nanoseconds()
				this.reportLock.Lock()
				this.processMessageDuration += duration
				this.processMessageSamples++
				if this.sbc.Profile {
					this.profileMessageDuration = this.processMessageDuration
//.........這裏部分代碼省略.........