plugin/forward: remove lenc and lencOut channels (#1726)

Remove these 2 channels, as they were only used in testing and
complicate things if we want to do a clean stop()

Less is more.

plugin/forward/persistent.go

@@ -31,11 +31,6 @@ type transport struct {
 	dial  chan string
 	yield chan connErr
 	ret   chan connErr
-
-	// Aid in testing, gets length of cache in data-race safe manner.
-	lenc    chan bool
-	lencOut chan int
-
 	stop  chan bool
 }
 
@@ -48,8 +43,6 @@ func newTransport(addr string, tlsConfig *tls.Config) *transport {
 		yield:  make(chan connErr),
 		ret:    make(chan connErr),
 		stop:   make(chan bool),
-		lenc:    make(chan bool),
-		lencOut: make(chan int),
 	}
 	go t.connManager()
 	return t
@@ -65,13 +58,6 @@ func (t *transport) len() int {
 	return l
 }
 
-// Len returns the number of connections in the cache.
-func (t *transport) Len() int {
-	t.lenc <- true
-	l := <-t.lencOut
-	return l
-}
-
 // connManagers manages the persistent connection cache for UDP and TCP.
 func (t *transport) connManager() {
 
@@ -128,13 +114,6 @@ Wait:
 
 		case <-t.stop:
 			return
-
-		case <-t.lenc:
-			l := 0
-			for _, conns := range t.conns {
-				l += len(conns)
-			}
-			t.lencOut <- l
 		}
 	}
 }

plugin/forward/persistent_test.go

@@ -30,28 +30,4 @@ func TestPersistent(t *testing.T) {
 	tr.Yield(c1)
 	tr.Yield(c2)
 	tr.Yield(c3)
-
-	if x := tr.Len(); x != 3 {
-		t.Errorf("Expected cache size to be 3, got %d", x)
-	}
-
-	c4, cache4, _ := tr.Dial("udp")
-	if x := tr.Len(); x != 2 {
-		t.Errorf("Expected cache size to be 2, got %d", x)
-	}
-
-	c5, cache5, _ := tr.Dial("udp")
-	if x := tr.Len(); x != 1 {
-		t.Errorf("Expected cache size to be 1, got %d", x)
-	}
-
-	if cache4 == false || cache5 == false {
-		t.Errorf("Expected cached connection")
-	}
-	tr.Yield(c4)
-	tr.Yield(c5)
-
-	if x := tr.Len(); x != 3 {
-		t.Errorf("Expected cache size to be 3, got %d", x)
-	}
 }