func main()

in example/flow/qps/qps_limit_example.go [31:93]
52 lines of code
7 McCabe index (conditional complexity)

func main() {
	// We should initialize Sentinel first.
	conf := config.NewDefaultConfig()
	// for testing, logging output to console
	conf.Sentinel.Log.Logger = logging.NewConsoleLogger()
	err := sentinel.InitWithConfig(conf)
	if err != nil {
		log.Fatal(err)
	}

	_, err = flow.LoadRules([]*flow.Rule{
		{
			Resource:               resName,
			TokenCalculateStrategy: flow.Direct,
			ControlBehavior:        flow.Reject,
			Threshold:              10,
			StatIntervalInMs:       1000,
		},
	})
	if err != nil {
		log.Fatalf("Unexpected error: %+v", err)
		return
	}

	ch := make(chan struct{})
	for i := 0; i < 10; i++ {
		go func() {
			for {
				e, b := sentinel.Entry(resName, sentinel.WithTrafficType(base.Inbound))
				if b != nil {
					// Blocked. We could get the block reason from the BlockError.
					time.Sleep(time.Duration(rand.Uint64()%10) * time.Millisecond)
				} else {
					// Passed, wrap the logic here.
					time.Sleep(time.Duration(rand.Uint64()%10) * time.Millisecond)

					// Be sure the entry is exited finally.
					e.Exit()
				}

			}
		}()
	}

	// Simulate a scenario in which flow rules are updated concurrently
	go func() {
		time.Sleep(time.Second * 10)
		_, err = flow.LoadRules([]*flow.Rule{
			{
				Resource:               resName,
				TokenCalculateStrategy: flow.Direct,
				ControlBehavior:        flow.Reject,
				Threshold:              80,
				StatIntervalInMs:       1000,
			},
		})
		if err != nil {
			log.Fatalf("Unexpected error: %+v", err)
			return
		}
	}()
	<-ch
}