From 13d152a873bc326ecb623dfe86a359c0ab724802 Mon Sep 17 00:00:00 2001
From: Hongchao Deng <hongchaodeng1@gmail.com>
Date: Mon, 23 Nov 2015 16:36:23 -0800
Subject: [PATCH] RateLimiter: change CanAccept() to TryAccept()

---
 pkg/apiserver/handlers_test.go            |  2 +-
 pkg/controller/node/rate_limited_queue.go |  2 +-
 pkg/kubelet/dockertools/docker.go         |  2 +-
 pkg/util/throttle.go                      |  9 +++++----
 pkg/util/throttle_test.go                 | 10 +++++-----
 plugin/pkg/scheduler/scheduler_test.go    |  4 ++--
 6 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/pkg/apiserver/handlers_test.go b/pkg/apiserver/handlers_test.go
index cabac4b8ea3..53078ec7557 100644
--- a/pkg/apiserver/handlers_test.go
+++ b/pkg/apiserver/handlers_test.go
@@ -35,7 +35,7 @@ import (
 type fakeRL bool
 
 func (fakeRL) Stop()             {}
-func (f fakeRL) CanAccept() bool { return bool(f) }
+func (f fakeRL) TryAccept() bool { return bool(f) }
 func (f fakeRL) Accept()         {}
 
 func expectHTTP(url string, code int, t *testing.T) {
diff --git a/pkg/controller/node/rate_limited_queue.go b/pkg/controller/node/rate_limited_queue.go
index 4545243a2e2..e934d4b4ae0 100644
--- a/pkg/controller/node/rate_limited_queue.go
+++ b/pkg/controller/node/rate_limited_queue.go
@@ -163,7 +163,7 @@ func (q *RateLimitedTimedQueue) Try(fn ActionFunc) {
 	val, ok := q.queue.Head()
 	for ok {
 		// rate limit the queue checking
-		if !q.limiter.CanAccept() {
+		if !q.limiter.TryAccept() {
 			glog.V(10).Info("Try rate limitted...")
 			// Try again later
 			break
diff --git a/pkg/kubelet/dockertools/docker.go b/pkg/kubelet/dockertools/docker.go
index 3ed9b9047c6..6fe8ce5bf03 100644
--- a/pkg/kubelet/dockertools/docker.go
+++ b/pkg/kubelet/dockertools/docker.go
@@ -197,7 +197,7 @@ func (p dockerPuller) Pull(image string, secrets []api.Secret) error {
 }
 
 func (p throttledDockerPuller) Pull(image string, secrets []api.Secret) error {
-	if p.limiter.CanAccept() {
+	if p.limiter.TryAccept() {
 		return p.puller.Pull(image, secrets)
 	}
 	return fmt.Errorf("pull QPS exceeded.")
diff --git a/pkg/util/throttle.go b/pkg/util/throttle.go
index 43fdc0a9462..b7d7785d90d 100644
--- a/pkg/util/throttle.go
+++ b/pkg/util/throttle.go
@@ -19,8 +19,9 @@ package util
 import "github.com/juju/ratelimit"
 
 type RateLimiter interface {
-	// CanAccept returns true if the rate is below the limit, false otherwise
-	CanAccept() bool
+	// TryAccept returns true if a token is taken immediately. Otherwise,
+	// it returns false.
+	TryAccept() bool
 	// Accept returns once a token becomes available.
 	Accept()
 	// Stop stops the rate limiter, subsequent calls to CanAccept will return false
@@ -47,7 +48,7 @@ func NewFakeRateLimiter() RateLimiter {
 	return &fakeRateLimiter{}
 }
 
-func (t *tickRateLimiter) CanAccept() bool {
+func (t *tickRateLimiter) TryAccept() bool {
 	return t.limiter.TakeAvailable(1) == 1
 }
 
@@ -59,7 +60,7 @@ func (t *tickRateLimiter) Accept() {
 func (t *tickRateLimiter) Stop() {
 }
 
-func (t *fakeRateLimiter) CanAccept() bool {
+func (t *fakeRateLimiter) TryAccept() bool {
 	return true
 }
 
diff --git a/pkg/util/throttle_test.go b/pkg/util/throttle_test.go
index b4b145b79db..b75553df17a 100644
--- a/pkg/util/throttle_test.go
+++ b/pkg/util/throttle_test.go
@@ -24,28 +24,28 @@ import (
 func TestBasicThrottle(t *testing.T) {
 	r := NewTokenBucketRateLimiter(1, 3)
 	for i := 0; i < 3; i++ {
-		if !r.CanAccept() {
+		if !r.TryAccept() {
 			t.Error("unexpected false accept")
 		}
 	}
-	if r.CanAccept() {
+	if r.TryAccept() {
 		t.Error("unexpected true accept")
 	}
 }
 
 func TestIncrementThrottle(t *testing.T) {
 	r := NewTokenBucketRateLimiter(1, 1)
-	if !r.CanAccept() {
+	if !r.TryAccept() {
 		t.Error("unexpected false accept")
 	}
-	if r.CanAccept() {
+	if r.TryAccept() {
 		t.Error("unexpected true accept")
 	}
 
 	// Allow to refill
 	time.Sleep(2 * time.Second)
 
-	if !r.CanAccept() {
+	if !r.TryAccept() {
 		t.Error("unexpected false accept")
 	}
 }
diff --git a/plugin/pkg/scheduler/scheduler_test.go b/plugin/pkg/scheduler/scheduler_test.go
index 6449e6b4665..e776fa8ee75 100644
--- a/plugin/pkg/scheduler/scheduler_test.go
+++ b/plugin/pkg/scheduler/scheduler_test.go
@@ -302,14 +302,14 @@ type FakeRateLimiter struct {
 	acceptValues []bool
 }
 
-func (fr *FakeRateLimiter) CanAccept() bool {
+func (fr *FakeRateLimiter) TryAccept() bool {
 	return true
 }
 
 func (fr *FakeRateLimiter) Stop() {}
 
 func (fr *FakeRateLimiter) Accept() {
-	fr.acceptValues = append(fr.acceptValues, fr.r.CanAccept())
+	fr.acceptValues = append(fr.acceptValues, fr.r.TryAccept())
 }
 
 func TestSchedulerRateLimitsBinding(t *testing.T) {