Test program for ratelimiter

Sample run

$ go  run test.go
Started at 2017-04-12 11:49:21.515360854 -0400 EDT
  Invoking at 2017-04-12 11:49:21.515439764 -0400 EDT
  Invoked  at 2017-04-12 11:49:21.515464339 -0400 EDT
    Called at 2017-04-12 11:49:21.515469714 -0400 EDT
  Invoking at 2017-04-12 11:49:22.515583917 -0400 EDT
  Invoking at 2017-04-12 11:49:23.51571878 -0400 EDT
  Invoking at 2017-04-12 11:49:24.515809571 -0400 EDT
  Invoking at 2017-04-12 11:49:25.515949779 -0400 EDT
      Returned at 2017-04-12 11:49:26.515627721 -0400 EDT
  Invoked  at 2017-04-12 11:49:26.515670754 -0400 EDT
  Invoked  at 2017-04-12 11:49:26.515689396 -0400 EDT
  Invoked  at 2017-04-12 11:49:26.515706142 -0400 EDT
  Invoked  at 2017-04-12 11:49:26.515711263 -0400 EDT
    Called at 2017-04-12 11:49:26.515833206 -0400 EDT
  Invoking at 2017-04-12 11:49:26.516058019 -0400 EDT
  Invoking at 2017-04-12 11:49:27.516254957 -0400 EDT
  Invoking at 2017-04-12 11:49:28.516314391 -0400 EDT
  Invoking at 2017-04-12 11:49:29.516441726 -0400 EDT
  Invoking at 2017-04-12 11:49:30.516592092 -0400 EDT
      Returned at 2017-04-12 11:49:31.515928309 -0400 EDT
  Invoked  at 2017-04-12 11:49:31.515973959 -0400 EDT
  Invoked  at 2017-04-12 11:49:31.515984402 -0400 EDT
  Invoked  at 2017-04-12 11:49:31.516001367 -0400 EDT
  Invoked  at 2017-04-12 11:49:31.51600642 -0400 EDT
  Invoked  at 2017-04-12 11:49:31.516011045 -0400 EDT
    Called at 2017-04-12 11:49:31.516024112 -0400 EDT
      Returned at 2017-04-12 11:49:36.516138415 -0400 EDT
Done at 2017-04-12 11:49:51.516849601 -0400 EDT

Called 3 times

test.go

package main

import (
	"fmt"
	"github.com/openshift/origin/pkg/util/ratelimiter"
	"sync"
	"time"
)

var runFreq = 3    // One every N seconds
var pauseSecs = 1  // Wait N seconds between kicking off tasks
var workSecs = 5   // How long to sleep in the work task
var totalSecs = 20 // Wait this long for all work

func main() {
	keyFunc := func(_ interface{}) (string, error) {
		return "blah", nil
	}

	h := &handler{}
	quit := make(chan struct{})
	rlf := ratelimiter.NewRateLimitedFunction(keyFunc, runFreq, h.handle)
	rlf.RunUntil(quit)

	fmt.Printf("Started at %s\n", time.Now())

	for i := 0; i < 10; i++ {
		go func() {
			fmt.Printf("  Invoking at %s\n", time.Now())
			rlf.Invoke(i)
			fmt.Printf("  Invoked  at %s\n", time.Now())
		}()
		time.Sleep(time.Duration(pauseSecs) * time.Second)
	}

	select {
	case <-time.After(time.Duration(totalSecs) * time.Second):
		close(quit)
		fmt.Printf("Done at %s\n\nCalled %d times\n", time.Now(), h.counter())
	}
}

type handler struct {
	_counter int
	sync.Mutex
}

func (h *handler) handle() error {
	h.Lock()
	defer h.Unlock()
	h._counter += 1

	fmt.Printf("    Called at %s\n", time.Now())
	time.Sleep(time.Duration(workSecs) * time.Second)
	fmt.Printf("      Returned at %s\n", time.Now())

	return nil
}

func (h *handler) counter() int {
	h.Lock()
	defer h.Unlock()
	return h._counter
}