Merge 3d88a77 into 1a179ab

circularbuffer.go

@@ -94,3 +94,15 @@ func (cb *CircularBuffer) Add(t time.Time) bool {
 	}
 	return false
 }
+
+func (cb *CircularBuffer) delta() time.Duration {
+	cb.RLock()
+	next := cb.slots[cb.offset]
+	curOff := cb.offset - 1
+	if curOff < 0 {
+		curOff += len(cb.slots)
+	}
+	cur := cb.slots[curOff]
+	cb.RUnlock()
+	return cur.Sub(next)
+}

circularbuffer_test.go

@@ -71,6 +71,21 @@ func TestFree(t *testing.T) {
 	}
 }
 
+func TestDelta(t *testing.T) {
+	l := 4
+	window := 1 * time.Second
+	cb := NewCircularBuffer(l, window)
+	start := time.Now()
+	for i := 0; i < l; i++ {
+		cb.Add(start.Add(time.Duration(i) * window))
+	}
+	want := time.Duration(3) * window
+	delta := cb.delta()
+	if delta != want {
+		t.Errorf("want != delta => %s / %s", want, delta)
+	}
+}
+
 func TestAdd(t *testing.T) {
 	l := 4
 	window := 1 * time.Second

ratelimit.go

@@ -13,6 +13,7 @@ type RateLimiter interface {
 	Allow(string) bool
 	// Close cleans up the RateLimiter implementation.
 	Close()
+	Delta(string) time.Duration
 }
 
 // NewRateLimiter returns a new initialized RateLimitter with maxHits
@@ -34,6 +35,10 @@ func (cb *CircularBuffer) Allow(s string) bool {
 func (cb *CircularBuffer) Close() {
 }
 
+func (cb *CircularBuffer) Delta(s string) time.Duration {
+	return cb.delta()
+}
+
 // ClientRateLimiter implements the RateLimiter interface and does
 // rate limiting based on the the String passed to Allow(). This can
 // be used to limit per client calls to the backend. For example you
@@ -81,6 +86,17 @@ func (rl *ClientRateLimiter) Allow(s string) bool {
 	return present
 }
 
+func (rl *ClientRateLimiter) Delta(s string) time.Duration {
+	rl.RLock()
+	if _, present := rl.bag[s]; !present {
+		rl.RUnlock()
+		return time.Duration(time.Hour * 24)
+	}
+	delta := rl.bag[s].delta()
+	rl.RUnlock()
+	return delta
+}
+
 // DeleteOld removes old entries from state bag
 func (rl *ClientRateLimiter) DeleteOld() {
 	rl.Lock()