// watchHandler watches w and keeps *resourceVersion up to date. func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, resyncCh <-chan time.Time, stopCh <-chan struct{}) error { start := time.Now() eventCount := 0 // Stopping the watcher should be idempotent and if we return from this function there's no way // we're coming back in with the same watch interface. defer w.Stop() loop: for { select { case <-stopCh: return errorStopRequested case <-resyncCh: return errorResyncRequested case event, ok := <-w.ResultChan(): if !ok { break loop } if event.Type == watch.Error { return apierrs.FromObject(event.Object) } if e, a := r.expectedType, reflect.TypeOf(event.Object); e != nil && e != a { util.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", r.name, e, a)) continue } meta, err := meta.Accessor(event.Object) if err != nil { util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event)) continue } newResourceVersion := meta.ResourceVersion() switch event.Type { case watch.Added: r.store.Add(event.Object) case watch.Modified: r.store.Update(event.Object) case watch.Deleted: // TODO: Will any consumers need access to the "last known // state", which is passed in event.Object? If so, may need // to change this. r.store.Delete(event.Object) default: util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event)) } *resourceVersion = newResourceVersion r.setLastSyncResourceVersion(newResourceVersion) eventCount++ } } watchDuration := time.Now().Sub(start) if watchDuration < 1*time.Second && eventCount == 0 { glog.V(4).Infof("%s: Unexpected watch close - watch lasted less than a second and no items received", r.name) return errors.New("very short watch") } glog.V(4).Infof("%s: Watch close - %v total %v items received", r.name, r.expectedType, eventCount) return nil }
func waitForPersistentVolumePhase(w watch.Interface, phase api.PersistentVolumePhase) { for { event := <-w.ResultChan() volume := event.Object.(*api.PersistentVolume) if volume.Status.Phase == phase { break } } }
// ensure the watch delivers the requested and only the requested items. func consume(t *testing.T, w watch.Interface, rvs []string, done *sync.WaitGroup) { defer done.Done() for _, rv := range rvs { got, ok := <-w.ResultChan() if !ok { t.Errorf("%#v: unexpected channel close, wanted %v", rvs, rv) return } gotRV := got.Object.(*api.Pod).ObjectMeta.ResourceVersion if e, a := rv, gotRV; e != a { t.Errorf("wanted %v, got %v", e, a) } else { t.Logf("Got %v as expected", gotRV) } } // We should not get anything else. got, open := <-w.ResultChan() if open { t.Errorf("%#v: unwanted object %#v", rvs, got) } }
// WatchLoop loops, passing events in w to fn. // If user sends interrupt signal, shut down cleanly. Otherwise, never return. func WatchLoop(w watch.Interface, fn func(watch.Event) error) { signals := make(chan os.Signal, 1) signal.Notify(signals, os.Interrupt) defer signal.Stop(signals) for { select { case event, ok := <-w.ResultChan(): if !ok { return } if err := fn(event); err != nil { w.Stop() } case <-signals: w.Stop() } } }