diff --git a/tools/cache/controller.go b/tools/cache/controller.go index bb4e1ad2..ff4c22de 100644 --- a/tools/cache/controller.go +++ b/tools/cache/controller.go @@ -17,6 +17,7 @@ limitations under the License. package cache import ( + "errors" "sync" "time" @@ -406,6 +407,49 @@ func NewTransformingIndexerInformer( return clientState, newInformer(lw, objType, resyncPeriod, h, clientState, transformer) } +// Multiplexes updates in the form of a list of Deltas into a Store, and informs +// a given handler of events OnUpdate, OnAdd, OnDelete +func processDeltas( + // Object which receives event notifications from the given deltas + handler ResourceEventHandler, + clientState Store, + transformer TransformFunc, + deltas Deltas, +) error { + // from oldest to newest + for _, d := range deltas { + obj := d.Object + if transformer != nil { + var err error + obj, err = transformer(obj) + if err != nil { + return err + } + } + + switch d.Type { + case Sync, Replaced, Added, Updated: + if old, exists, err := clientState.Get(obj); err == nil && exists { + if err := clientState.Update(obj); err != nil { + return err + } + handler.OnUpdate(old, obj) + } else { + if err := clientState.Add(obj); err != nil { + return err + } + handler.OnAdd(obj) + } + case Deleted: + if err := clientState.Delete(obj); err != nil { + return err + } + handler.OnDelete(obj) + } + } + return nil +} + // newInformer returns a controller for populating the store while also // providing event notifications. // @@ -444,38 +488,10 @@ func newInformer( RetryOnError: false, Process: func(obj interface{}) error { - // from oldest to newest - for _, d := range obj.(Deltas) { - obj := d.Object - if transformer != nil { - var err error - obj, err = transformer(obj) - if err != nil { - return err - } - } - - switch d.Type { - case Sync, Replaced, Added, Updated: - if old, exists, err := clientState.Get(obj); err == nil && exists { - if err := clientState.Update(obj); err != nil { - return err - } - h.OnUpdate(old, obj) - } else { - if err := clientState.Add(obj); err != nil { - return err - } - h.OnAdd(obj) - } - case Deleted: - if err := clientState.Delete(obj); err != nil { - return err - } - h.OnDelete(obj) - } + if deltas, ok := obj.(Deltas); ok { + return processDeltas(h, clientState, transformer, deltas) } - return nil + return errors.New("object given as Process argument is not Deltas") }, } return New(cfg) diff --git a/tools/cache/shared_informer.go b/tools/cache/shared_informer.go index 2ff493ec..9f42782d 100644 --- a/tools/cache/shared_informer.go +++ b/tools/cache/shared_informer.go @@ -17,6 +17,7 @@ limitations under the License. package cache import ( + "errors" "fmt" "sync" "time" @@ -180,6 +181,20 @@ type SharedInformer interface { // The handler should return quickly - any expensive processing should be // offloaded. SetWatchErrorHandler(handler WatchErrorHandler) error + + // The TransformFunc is called for each object which is about to be stored. + // + // This function is intended for you to take the opportunity to + // remove, transform, or normalize fields. One use case is to strip unused + // metadata fields out of objects to save on RAM cost. + // + // Must be set before starting the informer. + // + // Note: Since the object given to the handler may be already shared with + // other goroutines, it is advisable to copy the object being + // transform before mutating it at all and returning the copy to prevent + // data races. + SetTransform(handler TransformFunc) error } // SharedIndexInformer provides add and get Indexers ability based on SharedInformer. @@ -318,6 +333,8 @@ type sharedIndexInformer struct { // Called whenever the ListAndWatch drops the connection with an error. watchErrorHandler WatchErrorHandler + + transform TransformFunc } // dummyController hides the fact that a SharedInformer is different from a dedicated one @@ -365,6 +382,18 @@ func (s *sharedIndexInformer) SetWatchErrorHandler(handler WatchErrorHandler) er return nil } +func (s *sharedIndexInformer) SetTransform(handler TransformFunc) error { + s.startedLock.Lock() + defer s.startedLock.Unlock() + + if s.started { + return fmt.Errorf("informer has already started") + } + + s.transform = handler + return nil +} + func (s *sharedIndexInformer) Run(stopCh <-chan struct{}) { defer utilruntime.HandleCrash() @@ -538,45 +567,47 @@ func (s *sharedIndexInformer) HandleDeltas(obj interface{}) error { s.blockDeltas.Lock() defer s.blockDeltas.Unlock() - // from oldest to newest - for _, d := range obj.(Deltas) { - switch d.Type { - case Sync, Replaced, Added, Updated: - s.cacheMutationDetector.AddObject(d.Object) - if old, exists, err := s.indexer.Get(d.Object); err == nil && exists { - if err := s.indexer.Update(d.Object); err != nil { - return err - } + if deltas, ok := obj.(Deltas); ok { + return processDeltas(s, s.indexer, s.transform, deltas) + } + return errors.New("object given as Process argument is not Deltas") +} - isSync := false - switch { - case d.Type == Sync: - // Sync events are only propagated to listeners that requested resync - isSync = true - case d.Type == Replaced: - if accessor, err := meta.Accessor(d.Object); err == nil { - if oldAccessor, err := meta.Accessor(old); err == nil { - // Replaced events that didn't change resourceVersion are treated as resync events - // and only propagated to listeners that requested resync - isSync = accessor.GetResourceVersion() == oldAccessor.GetResourceVersion() - } - } - } - s.processor.distribute(updateNotification{oldObj: old, newObj: d.Object}, isSync) - } else { - if err := s.indexer.Add(d.Object); err != nil { - return err - } - s.processor.distribute(addNotification{newObj: d.Object}, false) - } - case Deleted: - if err := s.indexer.Delete(d.Object); err != nil { - return err - } - s.processor.distribute(deleteNotification{oldObj: d.Object}, false) +// Conforms to ResourceEventHandler +func (s *sharedIndexInformer) OnAdd(obj interface{}) { + // Invocation of this function is locked under s.blockDeltas, so it is + // save to distribute the notification + s.cacheMutationDetector.AddObject(obj) + s.processor.distribute(addNotification{newObj: obj}, false) +} + +// Conforms to ResourceEventHandler +func (s *sharedIndexInformer) OnUpdate(old, new interface{}) { + isSync := false + + // If is a Sync event, isSync should be true + // If is a Replaced event, isSync is true if resource version is unchanged. + // If RV is unchanged: this is a Sync/Replaced event, so isSync is true + + if accessor, err := meta.Accessor(new); err == nil { + if oldAccessor, err := meta.Accessor(old); err == nil { + // Events that didn't change resourceVersion are treated as resync events + // and only propagated to listeners that requested resync + isSync = accessor.GetResourceVersion() == oldAccessor.GetResourceVersion() } } - return nil + + // Invocation of this function is locked under s.blockDeltas, so it is + // save to distribute the notification + s.cacheMutationDetector.AddObject(new) + s.processor.distribute(updateNotification{oldObj: old, newObj: new}, isSync) +} + +// Conforms to ResourceEventHandler +func (s *sharedIndexInformer) OnDelete(old interface{}) { + // Invocation of this function is locked under s.blockDeltas, so it is + // save to distribute the notification + s.processor.distribute(deleteNotification{oldObj: old}, false) } // sharedProcessor has a collection of processorListener and can diff --git a/tools/cache/shared_informer_test.go b/tools/cache/shared_informer_test.go index ce129bd3..3f2ac71b 100644 --- a/tools/cache/shared_informer_test.go +++ b/tools/cache/shared_informer_test.go @@ -23,7 +23,7 @@ import ( "testing" "time" - "k8s.io/api/core/v1" + v1 "k8s.io/api/core/v1" "k8s.io/apimachinery/pkg/api/meta" metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" "k8s.io/apimachinery/pkg/util/sets" @@ -357,3 +357,36 @@ func TestSharedInformerErrorHandling(t *testing.T) { } close(stop) } + +func TestSharedInformerTransformer(t *testing.T) { + // source simulates an apiserver object endpoint. + source := fcache.NewFakeControllerSource() + + source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod1", UID: "pod1", ResourceVersion: "1"}}) + source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod2", UID: "pod2", ResourceVersion: "2"}}) + + informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second).(*sharedIndexInformer) + informer.SetTransform(func(obj interface{}) (interface{}, error) { + if pod, ok := obj.(*v1.Pod); ok { + name := pod.GetName() + + if upper := strings.ToUpper(name); upper != name { + copied := pod.DeepCopyObject().(*v1.Pod) + copied.SetName(upper) + return copied, nil + } + } + return obj, nil + }) + + listenerTransformer := newTestListener("listenerTransformer", 0, "POD1", "POD2") + informer.AddEventHandler(listenerTransformer) + + stop := make(chan struct{}) + go informer.Run(stop) + defer close(stop) + + if !listenerTransformer.ok() { + t.Errorf("%s: expected %v, got %v", listenerTransformer.name, listenerTransformer.expectedItemNames, listenerTransformer.receivedItemNames) + } +}