Unify variable naming between GuaranteedUpdate and Delete in storage

staging/src/k8s.io/apiserver/pkg/registry/generic/registry/dryrun.go

@@ -78,7 +78,7 @@ func (s *DryRunnableStorage) List(ctx context.Context, key string, opts storage.
 
 func (s *DryRunnableStorage) GuaranteedUpdate(
 	ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool,
-	preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, dryRun bool, suggestion runtime.Object) error {
+	preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, dryRun bool, cachedExistingObject runtime.Object) error {
 	if dryRun {
 		err := s.Storage.Get(ctx, key, storage.GetOptions{IgnoreNotFound: ignoreNotFound}, ptrToType)
 		if err != nil {
@@ -98,7 +98,7 @@ func (s *DryRunnableStorage) GuaranteedUpdate(
 		}
 		return s.copyInto(out, ptrToType)
 	}
-	return s.Storage.GuaranteedUpdate(ctx, key, ptrToType, ignoreNotFound, preconditions, tryUpdate, suggestion)
+	return s.Storage.GuaranteedUpdate(ctx, key, ptrToType, ignoreNotFound, preconditions, tryUpdate, cachedExistingObject)
 }
 
 func (s *DryRunnableStorage) Count(key string) (int64, error) {

staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go

@@ -752,6 +752,8 @@ func (c *Cacher) GuaranteedUpdate(
 	if elem, exists, err := c.watchCache.GetByKey(key); err != nil {
 		klog.Errorf("GetByKey returned error: %v", err)
 	} else if exists {
+		// DeepCopy the object since we modify resource version when serializing the
+		// current object.
 		currObj := elem.(*storeElement).Object.DeepCopyObject()
 		return c.storage.GuaranteedUpdate(ctx, key, ptrToType, ignoreNotFound, preconditions, tryUpdate, currObj)
 	}

staging/src/k8s.io/apiserver/pkg/storage/etcd3/store.go

@@ -285,7 +285,7 @@ func (s *store) conditionalDelete(
 // GuaranteedUpdate implements storage.Interface.GuaranteedUpdate.
 func (s *store) GuaranteedUpdate(
 	ctx context.Context, key string, out runtime.Object, ignoreNotFound bool,
-	preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, suggestion runtime.Object) error {
+	preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, cachedExistingObject runtime.Object) error {
 	trace := utiltrace.New("GuaranteedUpdate etcd3", utiltrace.Field{"type", getTypeName(out)})
 	defer trace.LogIfLong(500 * time.Millisecond)
 
@@ -306,12 +306,12 @@ func (s *store) GuaranteedUpdate(
 	}
 
 	var origState *objState
-	var mustCheckData bool
+	var origStateIsCurrent bool
-	if suggestion != nil {
+	if cachedExistingObject != nil {
-		origState, err = s.getStateFromObject(suggestion)
+		origState, err = s.getStateFromObject(cachedExistingObject)
-		mustCheckData = true
 	} else {
 		origState, err = getCurrentState()
+		origStateIsCurrent = true
 	}
 	if err != nil {
 		return err
@@ -322,7 +322,7 @@ func (s *store) GuaranteedUpdate(
 	for {
 		if err := preconditions.Check(key, origState.obj); err != nil {
 			// If our data is already up to date, return the error
-			if !mustCheckData {
+			if origStateIsCurrent {
 				return err
 			}
 
@@ -332,7 +332,7 @@ func (s *store) GuaranteedUpdate(
 			if err != nil {
 				return err
 			}
-			mustCheckData = false
+			origStateIsCurrent = true
 			// Retry
 			continue
 		}
@@ -340,7 +340,7 @@ func (s *store) GuaranteedUpdate(
 		ret, ttl, err := s.updateState(origState, tryUpdate)
 		if err != nil {
 			// If our data is already up to date, return the error
-			if !mustCheckData {
+			if origStateIsCurrent {
 				return err
 			}
 
@@ -350,7 +350,7 @@ func (s *store) GuaranteedUpdate(
 			if err != nil {
 				return err
 			}
-			mustCheckData = false
+			origStateIsCurrent = true
 			// Retry
 			continue
 		}
@@ -363,12 +363,12 @@ func (s *store) GuaranteedUpdate(
 			// if we skipped the original Get in this loop, we must refresh from
 			// etcd in order to be sure the data in the store is equivalent to
 			// our desired serialization
-			if mustCheckData {
+			if !origStateIsCurrent {
 				origState, err = getCurrentState()
 				if err != nil {
 					return err
 				}
-				mustCheckData = false
+				origStateIsCurrent = true
 				if !bytes.Equal(data, origState.data) {
 					// original data changed, restart loop
 					continue
@@ -412,7 +412,7 @@ func (s *store) GuaranteedUpdate(
 				return err
 			}
 			trace.Step("Retry value restored")
-			mustCheckData = false
+			origStateIsCurrent = true
 			continue
 		}
 		putResp := txnResp.Responses[0].GetResponsePut()

staging/src/k8s.io/apiserver/pkg/storage/interfaces.go

@@ -220,9 +220,9 @@ type Interface interface {
 	// or zero value in 'ptrToType' parameter otherwise.
 	// If the object to update has the same value as previous, it won't do any update
 	// but will return the object in 'ptrToType' parameter.
-	// If 'suggestion' is non-nil, it can be used as a suggestion about the current version
+	// If 'cachedExistingObject' is non-nil, it can be used as a suggestion about the
-	// of the object to avoid read operation from storage to get it. However, the
+	// current version of the object to avoid read operation from storage to get it.
-	// implementations have to retry in case suggestion is stale.
+	// However, the implementations have to retry in case suggestion is stale.
 	//
 	// Example:
 	//
@@ -244,7 +244,7 @@ type Interface interface {
 	// )
 	GuaranteedUpdate(
 		ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool,
-		precondtions *Preconditions, tryUpdate UpdateFunc, suggestion runtime.Object) error
+		precondtions *Preconditions, tryUpdate UpdateFunc, cachedExistingObject runtime.Object) error
 
 	// Count returns number of different entries under the key (generally being path prefix).
 	Count(key string) (int64, error)