Merge pull request #130925 from serathius/watchcache-snapshotter-interface

Create Snapshotter interface to fake the implementation

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

@@ -435,6 +435,16 @@ func newStoreSnapshotter() *storeSnapshotter {
 	return s
 }
 
+var _ Snapshotter = (*storeSnapshotter)(nil)
+
+type Snapshotter interface {
+	Reset()
+	GetLessOrEqual(rv uint64) (orderedLister, bool)
+	Add(rv uint64, indexer orderedLister)
+	RemoveLess(rv uint64)
+	Len() int
+}
+
 type storeSnapshotter struct {
 	mux       sync.RWMutex
 	snapshots *btree.BTreeG[rvSnapshot]
@@ -486,3 +496,10 @@ func (s *storeSnapshotter) RemoveLess(rv uint64) {
 		s.snapshots.DeleteMin()
 	}
 }
+
+func (s *storeSnapshotter) Len() int {
+	s.mux.RLock()
+	defer s.mux.RUnlock()
+
+	return s.snapshots.Len()
+}

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

@@ -137,3 +137,22 @@ func (f fakeOrderedLister) ListPrefix(prefixKey, continueKey string) []interface
 	return nil
 }
 func (f fakeOrderedLister) Count(prefixKey, continueKey string) int { return 0 }
+
+type fakeSnapshotter struct {
+	getLessOrEqual func(rv uint64) (orderedLister, bool)
+}
+
+var _ Snapshotter = (*fakeSnapshotter)(nil)
+
+func (f *fakeSnapshotter) Reset() {}
+func (f *fakeSnapshotter) GetLessOrEqual(rv uint64) (orderedLister, bool) {
+	if f.getLessOrEqual == nil {
+		return nil, false
+	}
+	return f.getLessOrEqual(rv)
+}
+func (f *fakeSnapshotter) Add(rv uint64, indexer orderedLister) {}
+func (f *fakeSnapshotter) RemoveLess(rv uint64)                 {}
+func (f *fakeSnapshotter) Len() int {
+	return 0
+}

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

@@ -154,7 +154,7 @@ type watchCache struct {
 	waitingUntilFresh *progress.ConditionalProgressRequester
 
 	// Stores previous snapshots of orderedLister to allow serving requests from previous revisions.
-	snapshots *storeSnapshotter
+	snapshots Snapshotter
 }
 
 func newWatchCache(

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

@@ -1363,7 +1363,7 @@ func TestCacheSnapshots(t *testing.T) {
 	clock.Step(DefaultEventFreshDuration + 1)
 	require.NoError(t, store.Update(makeTestPod("foo", 500)))
 	assert.Equal(t, 1, store.capacity)
-	assert.Equal(t, 1, store.snapshots.snapshots.Len())
+	assert.Equal(t, 1, store.snapshots.Len())
 	_, found = store.snapshots.GetLessOrEqual(499)
 	assert.False(t, found, "Expected overfilled cache to delete events below 500")
 
@@ -1377,7 +1377,7 @@ func TestCacheSnapshots(t *testing.T) {
 	t.Log("Add event to force capacity upsize")
 	require.NoError(t, store.Update(makeTestPod("foo", 600)))
 	assert.Equal(t, 2, store.capacity)
-	assert.Equal(t, 2, store.snapshots.snapshots.Len())
+	assert.Equal(t, 2, store.snapshots.Len())
 
 	t.Log("Test cache on rev 600")
 	lister, found = store.snapshots.GetLessOrEqual(600)