UPSTREAM: 54257: Use GetByKey() in typeLister_NonNamespacedGet

The Get() function of non-namespace lister passes a temporary object to
indexer.Get() in order to fetch the actual object from the indexer. This
may cause Go to allocate the temporary object on the heap instead of the
stack, as it is passed into interfaces. For non-namespaced objects,
Get(&Type{ObjectMeta: v1.ObjectMeta{Name: name}}) should be equivalent
to GetByKey(name).

This could be the root cause of excessive allocations, e.g. in tests
clusterRoleLister.Get() has trigger 4 billion allocations. See
openshift/origin#16954

Signed-off-by: Christian Heimes <[email protected]>

Author: tiran

staging/src/k8s.io/code-generator/cmd/lister-gen/generators/lister.go

@@ -323,8 +323,7 @@ func (s *$.type|private$Lister) $.type|publicPlural$(namespace string) $.type|pu
 var typeLister_NonNamespacedGet = `
 // Get retrieves the $.type|public$ from the index for a given name.
 func (s *$.type|private$Lister) Get(name string) (*$.type|raw$, error) {
-  key := &$.type|raw${ObjectMeta: $.objectMeta|raw${Name: name}}
-  obj, exists, err := s.indexer.Get(key)
+  obj, exists, err := s.indexer.GetByKey(name)
   if err != nil {
     return nil, err
   }