Golang watch.Interface类代码示例

// Until reads items from the watch until each provided condition succeeds, and then returns the last watch
// encountered. The first condition that returns an error terminates the watch (and the event is also returned).
// If no event has been received, the returned event will be nil.
// TODO: move to pkg/watch upstream
func Until(timeout time.Duration, watcher watch.Interface, conditions ...WatchConditionFunc) (*watch.Event, error) {
	ch := watcher.ResultChan()
	defer watcher.Stop()
	var after <-chan time.Time
	if timeout > 0 {
		after = time.After(timeout)
	} else {
		ch := make(chan time.Time)
		close(ch)
		after = ch
	}
	var lastEvent *watch.Event
	for _, condition := range conditions {
		for {
			select {
			case event, ok := <-ch:
				if !ok {
					return lastEvent, wait.ErrWaitTimeout
				}
				lastEvent = &event
				// TODO: check for watch expired error and retry watch from latest point?
				done, err := condition(event)
				if err != nil {
					return lastEvent, err
				}
				if done {
					return lastEvent, nil
				}
			case <-after:
				return lastEvent, wait.ErrWaitTimeout
			}
		}
	}
	return lastEvent, wait.ErrWaitTimeout
}

// 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 {
				utilruntime.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 {
				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
				continue
			}
			newResourceVersion := meta.GetResourceVersion()
			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:
				utilruntime.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 waitForWatch(t *testing.T, name string, w watchapi.Interface) *watchapi.Event {
	select {
	case e := <-w.ResultChan():
		return &e
	case <-time.After(BuildControllersWatchTimeout):
		t.Fatalf("Timed out waiting for watch: %s", name)
		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
		}
	}
}

func observeCreation(w watch.Interface) {
	select {
	case event, _ := <-w.ResultChan():
		if event.Type != watch.Added {
			framework.Failf("Failed to observe the creation: %v", event)
		}
	case <-time.After(30 * time.Second):
		framework.Failf("Timeout while waiting for observing the creation")
	}
}

func testCheckStop(t *testing.T, i int, w watch.Interface) {
	select {
	case _, ok := <-w.ResultChan():
		if ok {
			t.Errorf("#%d: ResultChan should have been closed", i)
		}
	case <-time.After(wait.ForeverTestTimeout):
		t.Errorf("#%d: time out after waiting 1s on ResultChan", i)
	}
}

func testCheckEventType(t *testing.T, expectEventType watch.EventType, w watch.Interface) {
	select {
	case res := <-w.ResultChan():
		if res.Type != expectEventType {
			t.Errorf("event type want=%v, get=%v", expectEventType, res.Type)
		}
	case <-time.After(wait.ForeverTestTimeout):
		t.Errorf("time out after waiting %v on ResultChan", wait.ForeverTestTimeout)
	}
}

func observePodCreation(w watch.Interface) {
	select {
	case event, _ := <-w.ResultChan():
		if event.Type != watch.Added {
			framework.Failf("Failed to observe pod creation: %v", event)
		}
	case <-time.After(framework.PodStartTimeout):
		Fail("Timeout while waiting for pod creation")
	}
}

func (i ingester) ingest(in watch.Interface, out chan<- Event, c context.Context) {
	for {
		select {
		case <-c.Done():
			logf(i).Debug("Closing ingest channel")
			return
		case e := <-in.ResultChan():
			out <- Event{e}
		}
	}
}

func waitForAnyPersistentVolumeClaimPhase(w watch.Interface, phase api.PersistentVolumeClaimPhase) {
	for {
		event := <-w.ResultChan()
		claim, ok := event.Object.(*api.PersistentVolumeClaim)
		if !ok {
			continue
		}
		if claim.Status.Phase == phase {
			glog.V(2).Infof("claim %q is %s", claim.Name, phase)
			break
		}
	}
}

func verifyWatchEvent(t *testing.T, w watch.Interface, eventType watch.EventType, eventObject runtime.Object) {
	select {
	case event := <-w.ResultChan():
		if e, a := eventType, event.Type; e != a {
			t.Errorf("Expected: %s, got: %s", eventType, event.Type)
		}
		if e, a := eventObject, event.Object; !api.Semantic.DeepDerivative(e, a) {
			t.Errorf("Expected (%s): %#v, got: %#v", eventType, e, a)
		}
	case <-time.After(wait.ForeverTestTimeout):
		t.Errorf("Timed out waiting for an event")
	}
}

func waitForAnyPersistentVolumePhase(w watch.Interface, phase api.PersistentVolumePhase) {
	for {
		event := <-w.ResultChan()
		volume, ok := event.Object.(*api.PersistentVolume)
		if !ok {
			continue
		}
		if volume.Status.Phase == phase {
			glog.V(2).Infof("volume %q is %s", volume.Name, phase)
			break
		}
	}
}

func filterEvents(t *testing.T, ignoreBuilds map[string]struct{}, buildWatch watchapi.Interface) (newBuild *buildapi.Build, event watchapi.Event) {
	for {
		event = <-buildWatch.ResultChan()
		var ok bool
		newBuild, ok = event.Object.(*buildapi.Build)
		if !ok {
			t.Errorf("unexpected event type (not a Build): %v", event.Object)
		}
		if _, exists := ignoreBuilds[newBuild.Name]; !exists {
			break
		}
	}
	return
}

func waitForOnlyDelete(projectName string, w watch.Interface, t *testing.T) {
	select {
	case event := <-w.ResultChan():
		project := event.Object.(*projectapi.Project)
		t.Logf("got %#v %#v", event, project)
		if event.Type == watch.Deleted && project.Name == projectName {
			return
		}
		t.Errorf("got unexpected project %v", project.Name)

	case <-time.After(30 * time.Second):
		t.Fatalf("timeout: %v", projectName)
	}
}

func testCheckResult(t *testing.T, i int, expectEventType watch.EventType, w watch.Interface, expectObj *api.Pod) {
	select {
	case res := <-w.ResultChan():
		if res.Type != expectEventType {
			t.Errorf("#%d: event type want=%v, get=%v", i, expectEventType, res.Type)
			return
		}
		if !reflect.DeepEqual(expectObj, res.Object) {
			t.Errorf("#%d: obj want=\n%#v\nget=\n%#v", i, expectObj, res.Object)
		}
	case <-time.After(wait.ForeverTestTimeout):
		t.Errorf("#%d: time out after waiting %v on ResultChan", i, wait.ForeverTestTimeout)
	}
}