Avoid deep copying objects twice in the CacheReader List method #621
Description
In the List method of the CacheReader, the list of objects retrieved from the index is added to the runtimeObjs array by deep copying each object. This array is then passed to the objectutil.FilterWithLabels which again creates a deep copy of the objects that match the label selector.
It would be more efficient to inline the label filtering logic as follows to avoid this extra work and reduce heap usage of controllers that work with large number of items.
diff --git a/pkg/cache/internal/cache_reader.go b/pkg/cache/internal/cache_reader.go
index a9b7ae34..8564a2da 100644
--- a/pkg/cache/internal/cache_reader.go
+++ b/pkg/cache/internal/cache_reader.go
@@ -30,7 +30,6 @@ import (
"k8s.io/apimachinery/pkg/selection"
"k8s.io/client-go/tools/cache"
"sigs.k8s.io/controller-runtime/pkg/client"
- "sigs.k8s.io/controller-runtime/pkg/internal/objectutil"
)
// CacheReader is a CacheReader
@@ -125,15 +124,22 @@ func (c *CacheReader) List(_ context.Context, out runtime.Object, opts ...client
if !isObj {
return fmt.Errorf("cache contained %T, which is not an Object", obj)
}
+ meta, err := apimeta.Accessor(obj)
+ if err != nil {
+ return err
+ }
+ if labelSel != nil {
+ lbls := labels.Set(meta.GetLabels())
+ if !labelSel.Matches(lbls) {
+ continue
+ }
+ }
+
outObj := obj.DeepCopyObject()
outObj.GetObjectKind().SetGroupVersionKind(c.groupVersionKind)
runtimeObjs = append(runtimeObjs, outObj)
}
- filteredItems, err := objectutil.FilterWithLabels(runtimeObjs, labelSel)
- if err != nil {
- return err
- }
- return apimeta.SetList(out, filteredItems)
+ return apimeta.SetList(out, runtimeObjs)
}
// objectKeyToStorageKey converts an object key to store key.Are there any downsides to patching the method as suggested? If not, I'll be happy to raise a PR.