no-op timer

common/signal/timer.go

@@ -5,21 +5,25 @@ import (
 	"time"
 )
 
-type ActivityTimer struct {
+type ActivityTimer interface {
+	Update()
+}
+
+type realActivityTimer struct {
 	updated chan bool
 	timeout time.Duration
 	ctx     context.Context
 	cancel  context.CancelFunc
 }
 
-func (t *ActivityTimer) Update() {
+func (t *realActivityTimer) Update() {
 	select {
 	case t.updated <- true:
 	default:
 	}
 }
 
-func (t *ActivityTimer) run() {
+func (t *realActivityTimer) run() {
 	for {
 		select {
 		case <-time.After(t.timeout):
@@ -37,9 +41,9 @@ func (t *ActivityTimer) run() {
 	}
 }
 
-func CancelAfterInactivity(ctx context.Context, timeout time.Duration) (context.Context, *ActivityTimer) {
+func CancelAfterInactivity(ctx context.Context, timeout time.Duration) (context.Context, ActivityTimer) {
 	ctx, cancel := context.WithCancel(ctx)
-	timer := &ActivityTimer{
+	timer := &realActivityTimer{
 		ctx:     ctx,
 		cancel:  cancel,
 		timeout: timeout,
@@ -48,3 +52,11 @@ func CancelAfterInactivity(ctx context.Context, timeout time.Duration) (context.
 	go timer.run()
 	return ctx, timer
 }
+
+type noOpActivityTimer struct{}
+
+func (noOpActivityTimer) Update() {}
+
+func BackgroundTimer() ActivityTimer {
+	return noOpActivityTimer{}
+}