add a blocking accept method to RateLimiter

pkg/util/throttle.go

@@ -24,6 +24,8 @@ import (
 type RateLimiter interface {
 	// CanAccept returns true if the rate is below the limit, false otherwise
 	CanAccept() bool
+	// Accept returns once a token becomes available.
+	Accept()
 	// Stop stops the rate limiter, subsequent calls to CanAccept will return false
 	Stop()
 }
@@ -73,6 +75,11 @@ func (t *tickRateLimiter) CanAccept() bool {
 	}
 }
 
+// Accept will block until a token becomes available
+func (t *tickRateLimiter) Accept() {
+	<-t.tokens
+}
+
 func (t *tickRateLimiter) Stop() {
 	close(t.stop)
 }