client-go bucket rate limiter add maxDelay

Kubernetes-commit: 57ec8336195702dd0d5f6f19fd3907e2a6a615a8

util/workqueue/default_rate_limiters.go

@@ -209,3 +209,30 @@ func (r *MaxOfRateLimiter) Forget(item interface{}) {
 		limiter.Forget(item)
 	}
 }
+
+// WithMaxWaitRateLimiter have maxDelay which avoids waiting too long
+type WithMaxWaitRateLimiter struct {
+	limiter  RateLimiter
+	maxDelay time.Duration
+}
+
+func NewWithMaxWaitRateLimiter(limiter RateLimiter, maxDelay time.Duration) RateLimiter {
+	return &WithMaxWaitRateLimiter{limiter: limiter, maxDelay: maxDelay}
+}
+
+func (w WithMaxWaitRateLimiter) When(item interface{}) time.Duration {
+	delay := w.limiter.When(item)
+	if delay > w.maxDelay {
+		return w.maxDelay
+	}
+
+	return delay
+}
+
+func (w WithMaxWaitRateLimiter) Forget(item interface{}) {
+	w.limiter.Forget(item)
+}
+
+func (w WithMaxWaitRateLimiter) NumRequeues(item interface{}) int {
+	return w.limiter.NumRequeues(item)
+}

util/workqueue/default_rate_limiters_test.go

@@ -182,3 +182,24 @@ func TestMaxOfRateLimiter(t *testing.T) {
 	}
 
 }
+
+func TestWithMaxWaitRateLimiter(t *testing.T) {
+	limiter := NewWithMaxWaitRateLimiter(DefaultControllerRateLimiter(), 500*time.Second)
+	for i := 0; i < 100; i++ {
+		if e, a := 5*time.Millisecond, limiter.When(i); e != a {
+			t.Errorf("expected %v, got %v", e, a)
+		}
+	}
+
+	for i := 100; i < 5100; i++ {
+		if e, a := 500*time.Second, limiter.When(i); e < a {
+			t.Errorf("expected %v, got %v", e, a)
+		}
+	}
+
+	for i := 5100; i < 5200; i++ {
+		if e, a := 500*time.Second, limiter.When(i); e != a {
+			t.Errorf("expected %v, got %v", e, a)
+		}
+	}
+}