Refactor cacher.ListerWatcher code structure

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

@@ -400,7 +400,7 @@ func NewCacherFromConfig(config Config) (*Cacher, error) {
 
 	watchCache := newWatchCache(
 		config.KeyFunc, cacher.processEvent, config.GetAttrsFunc, config.Versioner, config.Indexers, config.Clock, config.GroupResource)
-	listerWatcher := NewCacherListerWatcher(config.Storage, config.ResourcePrefix, config.NewListFunc)
+	listerWatcher := NewListerWatcher(config.Storage, config.ResourcePrefix, config.NewListFunc)
 	reflectorName := "storage/cacher.go:" + config.ResourcePrefix
 
 	reflector := cache.NewNamedReflector(reflectorName, listerWatcher, obj, watchCache, 0)
@@ -1336,54 +1336,6 @@ func (c *Cacher) waitUntilWatchCacheFreshAndForceAllEvents(ctx context.Context,
 	return false, nil
 }
 
-// cacherListerWatcher opaques storage.Interface to expose cache.ListerWatcher.
-type cacherListerWatcher struct {
-	storage        storage.Interface
-	resourcePrefix string
-	newListFunc    func() runtime.Object
-}
-
-// NewCacherListerWatcher returns a storage.Interface backed ListerWatcher.
-func NewCacherListerWatcher(storage storage.Interface, resourcePrefix string, newListFunc func() runtime.Object) cache.ListerWatcher {
-	return &cacherListerWatcher{
-		storage:        storage,
-		resourcePrefix: resourcePrefix,
-		newListFunc:    newListFunc,
-	}
-}
-
-// Implements cache.ListerWatcher interface.
-func (lw *cacherListerWatcher) List(options metav1.ListOptions) (runtime.Object, error) {
-	list := lw.newListFunc()
-	pred := storage.SelectionPredicate{
-		Label:    labels.Everything(),
-		Field:    fields.Everything(),
-		Limit:    options.Limit,
-		Continue: options.Continue,
-	}
-
-	storageOpts := storage.ListOptions{
-		ResourceVersionMatch: options.ResourceVersionMatch,
-		Predicate:            pred,
-		Recursive:            true,
-	}
-	if err := lw.storage.GetList(context.TODO(), lw.resourcePrefix, storageOpts, list); err != nil {
-		return nil, err
-	}
-	return list, nil
-}
-
-// Implements cache.ListerWatcher interface.
-func (lw *cacherListerWatcher) Watch(options metav1.ListOptions) (watch.Interface, error) {
-	opts := storage.ListOptions{
-		ResourceVersion: options.ResourceVersion,
-		Predicate:       storage.Everything,
-		Recursive:       true,
-		ProgressNotify:  true,
-	}
-	return lw.storage.Watch(context.TODO(), lw.resourcePrefix, opts)
-}
-
 // errWatcher implements watch.Interface to return a single error
 type errWatcher struct {
 	result chan watch.Event

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

@@ -0,0 +1,77 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cacher
+
+import (
+	"context"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/apiserver/pkg/storage"
+	"k8s.io/client-go/tools/cache"
+)
+
+// listerWatcher opaques storage.Interface to expose cache.ListerWatcher.
+type listerWatcher struct {
+	storage        storage.Interface
+	resourcePrefix string
+	newListFunc    func() runtime.Object
+}
+
+// NewListerWatcher returns a storage.Interface backed ListerWatcher.
+func NewListerWatcher(storage storage.Interface, resourcePrefix string, newListFunc func() runtime.Object) cache.ListerWatcher {
+	return &listerWatcher{
+		storage:        storage,
+		resourcePrefix: resourcePrefix,
+		newListFunc:    newListFunc,
+	}
+}
+
+// Implements cache.ListerWatcher interface.
+func (lw *listerWatcher) List(options metav1.ListOptions) (runtime.Object, error) {
+	list := lw.newListFunc()
+	pred := storage.SelectionPredicate{
+		Label:    labels.Everything(),
+		Field:    fields.Everything(),
+		Limit:    options.Limit,
+		Continue: options.Continue,
+	}
+
+	storageOpts := storage.ListOptions{
+		ResourceVersionMatch: options.ResourceVersionMatch,
+		Predicate:            pred,
+		Recursive:            true,
+	}
+	if err := lw.storage.GetList(context.TODO(), lw.resourcePrefix, storageOpts, list); err != nil {
+		return nil, err
+	}
+	return list, nil
+}
+
+// Implements cache.ListerWatcher interface.
+func (lw *listerWatcher) Watch(options metav1.ListOptions) (watch.Interface, error) {
+	opts := storage.ListOptions{
+		ResourceVersion: options.ResourceVersion,
+		Predicate:       storage.Everything,
+		Recursive:       true,
+		ProgressNotify:  true,
+	}
+	return lw.storage.Watch(context.TODO(), lw.resourcePrefix, opts)
+}

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

@@ -0,0 +1,144 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cacher
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/api/apitesting"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apiserver/pkg/apis/example"
+	examplev1 "k8s.io/apiserver/pkg/apis/example/v1"
+	"k8s.io/apiserver/pkg/storage"
+	"k8s.io/apiserver/pkg/storage/etcd3"
+	etcd3testing "k8s.io/apiserver/pkg/storage/etcd3/testing"
+	"k8s.io/apiserver/pkg/storage/value/encrypt/identity"
+)
+
+func newPod() runtime.Object { return &example.Pod{} }
+
+func newEtcdTestStorage(t *testing.T, prefix string) (*etcd3testing.EtcdTestServer, storage.Interface) {
+	server, _ := etcd3testing.NewUnsecuredEtcd3TestClientServer(t)
+	storage := etcd3.New(
+		server.V3Client,
+		apitesting.TestCodec(codecs, examplev1.SchemeGroupVersion),
+		newPod, prefix,
+		schema.GroupResource{Resource: "pods"},
+		identity.NewEncryptCheckTransformer(),
+		true,
+		etcd3.NewDefaultLeaseManagerConfig())
+	return server, storage
+}
+
+func TestCacherListerWatcher(t *testing.T) {
+	prefix := "pods"
+	fn := func() runtime.Object { return &example.PodList{} }
+	server, store := newEtcdTestStorage(t, prefix)
+	defer server.Terminate(t)
+
+	objects := []*example.Pod{
+		{ObjectMeta: metav1.ObjectMeta{Name: "bar", Namespace: "test-ns"}},
+		{ObjectMeta: metav1.ObjectMeta{Name: "baz", Namespace: "test-ns"}},
+		{ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "test-ns"}},
+	}
+	for _, obj := range objects {
+		out := &example.Pod{}
+		key := fmt.Sprintf("/pods/%s/%s", obj.Namespace, obj.Name)
+		if err := store.Create(context.Background(), key, obj, out, 0); err != nil {
+			t.Fatalf("Create failed: %v", err)
+		}
+	}
+
+	lw := NewListerWatcher(store, prefix, fn)
+
+	obj, err := lw.List(metav1.ListOptions{})
+	if err != nil {
+		t.Fatalf("List failed: %v", err)
+	}
+	pl, ok := obj.(*example.PodList)
+	if !ok {
+		t.Fatalf("Expected PodList but got %v", pl)
+	}
+	if len(pl.Items) != 3 {
+		t.Errorf("Expected PodList of length 3 but got %d", len(pl.Items))
+	}
+}
+
+func TestCacherListerWatcherPagination(t *testing.T) {
+	prefix := "pods"
+	fn := func() runtime.Object { return &example.PodList{} }
+	server, store := newEtcdTestStorage(t, prefix)
+	defer server.Terminate(t)
+
+	// We need the list to be sorted by name to later check the alphabetical order of
+	// returned results.
+	objects := []*example.Pod{
+		{ObjectMeta: metav1.ObjectMeta{Name: "bar", Namespace: "test-ns"}},
+		{ObjectMeta: metav1.ObjectMeta{Name: "baz", Namespace: "test-ns"}},
+		{ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "test-ns"}},
+	}
+	for _, obj := range objects {
+		out := &example.Pod{}
+		key := fmt.Sprintf("/pods/%s/%s", obj.Namespace, obj.Name)
+		if err := store.Create(context.Background(), key, obj, out, 0); err != nil {
+			t.Fatalf("Create failed: %v", err)
+		}
+	}
+
+	lw := NewListerWatcher(store, prefix, fn)
+
+	obj1, err := lw.List(metav1.ListOptions{Limit: 2})
+	if err != nil {
+		t.Fatalf("List failed: %v", err)
+	}
+	limit1, ok := obj1.(*example.PodList)
+	if !ok {
+		t.Fatalf("Expected PodList but got %v", limit1)
+	}
+	if len(limit1.Items) != 2 {
+		t.Errorf("Expected PodList of length 2 but got %d", len(limit1.Items))
+	}
+	if limit1.Continue == "" {
+		t.Errorf("Expected list to have Continue but got none")
+	}
+	obj2, err := lw.List(metav1.ListOptions{Limit: 2, Continue: limit1.Continue})
+	if err != nil {
+		t.Fatalf("List failed: %v", err)
+	}
+	limit2, ok := obj2.(*example.PodList)
+	if !ok {
+		t.Fatalf("Expected PodList but got %v", limit2)
+	}
+	if limit2.Continue != "" {
+		t.Errorf("Expected list not to have Continue, but got %s", limit1.Continue)
+	}
+
+	if limit1.Items[0].Name != objects[0].Name {
+		t.Errorf("Expected list1.Items[0] to be %s but got %s", objects[0].Name, limit1.Items[0].Name)
+	}
+	if limit1.Items[1].Name != objects[1].Name {
+		t.Errorf("Expected list1.Items[1] to be %s but got %s", objects[1].Name, limit1.Items[1].Name)
+	}
+	if limit2.Items[0].Name != objects[2].Name {
+		t.Errorf("Expected list2.Items[0] to be %s but got %s", objects[2].Name, limit2.Items[0].Name)
+	}
+
+}

staging/src/k8s.io/apiserver/pkg/storage/tests/cacher_test.go

@@ -557,89 +557,6 @@ func TestEmptyWatchEventCache(t *testing.T) {
 	}
 }
 
-func TestCacherListerWatcher(t *testing.T) {
-	prefix := "pods"
-	fn := func() runtime.Object { return &example.PodList{} }
-	server, store := newEtcdTestStorage(t, prefix, true)
-	defer server.Terminate(t)
-
-	podFoo := makeTestPod("foo")
-	podBar := makeTestPod("bar")
-	podBaz := makeTestPod("baz")
-
-	_ = updatePod(t, store, podFoo, nil)
-	_ = updatePod(t, store, podBar, nil)
-	_ = updatePod(t, store, podBaz, nil)
-
-	lw := cacherstorage.NewCacherListerWatcher(store, prefix, fn)
-
-	obj, err := lw.List(metav1.ListOptions{})
-	if err != nil {
-		t.Fatalf("List failed: %v", err)
-	}
-	pl, ok := obj.(*example.PodList)
-	if !ok {
-		t.Fatalf("Expected PodList but got %v", pl)
-	}
-	if len(pl.Items) != 3 {
-		t.Errorf("Expected PodList of length 3 but got %d", len(pl.Items))
-	}
-}
-
-func TestCacherListerWatcherPagination(t *testing.T) {
-	prefix := "pods"
-	fn := func() runtime.Object { return &example.PodList{} }
-	server, store := newEtcdTestStorage(t, prefix, true)
-	defer server.Terminate(t)
-
-	podFoo := makeTestPod("foo")
-	podBar := makeTestPod("bar")
-	podBaz := makeTestPod("baz")
-
-	_ = updatePod(t, store, podFoo, nil)
-	_ = updatePod(t, store, podBar, nil)
-	_ = updatePod(t, store, podBaz, nil)
-
-	lw := cacherstorage.NewCacherListerWatcher(store, prefix, fn)
-
-	obj1, err := lw.List(metav1.ListOptions{Limit: 2})
-	if err != nil {
-		t.Fatalf("List failed: %v", err)
-	}
-	limit1, ok := obj1.(*example.PodList)
-	if !ok {
-		t.Fatalf("Expected PodList but got %v", limit1)
-	}
-	if len(limit1.Items) != 2 {
-		t.Errorf("Expected PodList of length 2 but got %d", len(limit1.Items))
-	}
-	if limit1.Continue == "" {
-		t.Errorf("Expected list to have Continue but got none")
-	}
-	obj2, err := lw.List(metav1.ListOptions{Limit: 2, Continue: limit1.Continue})
-	if err != nil {
-		t.Fatalf("List failed: %v", err)
-	}
-	limit2, ok := obj2.(*example.PodList)
-	if !ok {
-		t.Fatalf("Expected PodList but got %v", limit2)
-	}
-	if limit2.Continue != "" {
-		t.Errorf("Expected list not to have Continue, but got %s", limit1.Continue)
-	}
-
-	if limit1.Items[0].Name != podBar.Name {
-		t.Errorf("Expected list1.Items[0] to be %s but got %s", podBar.Name, limit1.Items[0].Name)
-	}
-	if limit1.Items[1].Name != podBaz.Name {
-		t.Errorf("Expected list1.Items[1] to be %s but got %s", podBaz.Name, limit1.Items[1].Name)
-	}
-	if limit2.Items[0].Name != podFoo.Name {
-		t.Errorf("Expected list2.Items[0] to be %s but got %s", podFoo.Name, limit2.Items[0].Name)
-	}
-
-}
-
 func TestWatchDispatchBookmarkEvents(t *testing.T) {
 	ctx, cacher, terminate := testSetup(t)
 	t.Cleanup(terminate)