Remove Saturation() from rate limiter interface

Kubernetes-commit: a9ed90f227f07fab2da75541d57a5366ddb38f66

util/flowcontrol/throttle.go

@@ -30,11 +30,6 @@ type RateLimiter interface {
 	Accept()
 	// Stop stops the rate limiter, subsequent calls to CanAccept will return false
 	Stop()
-	// Saturation returns a percentage number which describes how saturated
-	// this rate limiter is.
-	// Usually we use token bucket rate limiter. In that case,
-	// 1.0 means no tokens are available; 0.0 means we have a full bucket of tokens to use.
-	Saturation() float64
 	// QPS returns QPS of this rate limiter
 	QPS() float32
 }
@@ -77,12 +72,6 @@ func (t *tokenBucketRateLimiter) TryAccept() bool {
 	return t.limiter.TakeAvailable(1) == 1
 }
 
-func (t *tokenBucketRateLimiter) Saturation() float64 {
-	capacity := t.limiter.Capacity()
-	avail := t.limiter.Available()
-	return float64(capacity-avail) / float64(capacity)
-}
-
 // Accept will block until a token becomes available
 func (t *tokenBucketRateLimiter) Accept() {
 	t.limiter.Wait(1)
@@ -105,10 +94,6 @@ func (t *fakeAlwaysRateLimiter) TryAccept() bool {
 	return true
 }
 
-func (t *fakeAlwaysRateLimiter) Saturation() float64 {
-	return 0
-}
-
 func (t *fakeAlwaysRateLimiter) Stop() {}
 
 func (t *fakeAlwaysRateLimiter) Accept() {}
@@ -131,10 +116,6 @@ func (t *fakeNeverRateLimiter) TryAccept() bool {
 	return false
 }
 
-func (t *fakeNeverRateLimiter) Saturation() float64 {
-	return 1
-}
-
 func (t *fakeNeverRateLimiter) Stop() {
 	t.wg.Done()
 }

util/flowcontrol/throttle_test.go

@@ -17,7 +17,6 @@ limitations under the License.
 package flowcontrol
 
 import (
-	"math"
 	"sync"
 	"testing"
 	"time"
@@ -116,29 +115,6 @@ func TestThrottle(t *testing.T) {
 	}
 }
 
-func TestRateLimiterSaturation(t *testing.T) {
-	const e = 0.000001
-	tests := []struct {
-		capacity int
-		take     int
-
-		expectedSaturation float64
-	}{
-		{1, 1, 1},
-		{10, 3, 0.3},
-	}
-	for i, tt := range tests {
-		rl := NewTokenBucketRateLimiter(1, tt.capacity)
-		for i := 0; i < tt.take; i++ {
-			rl.Accept()
-		}
-		if math.Abs(rl.Saturation()-tt.expectedSaturation) > e {
-			t.Fatalf("#%d: Saturation rate difference isn't within tolerable range\n want=%f, get=%f",
-				i, tt.expectedSaturation, rl.Saturation())
-		}
-	}
-}
-
 func TestAlwaysFake(t *testing.T) {
 	rl := NewFakeAlwaysRateLimiter()
 	if !rl.TryAccept() {