From 6e6ec6c0eeecd52fc43e574f3a615a00b33211f3 Mon Sep 17 00:00:00 2001
From: Steve Kuznetsov <skuznets@redhat.com>
Date: Thu, 19 May 2022 08:28:13 -0700
Subject: [PATCH] customresource: stop shallow-copying metadata

We no longer mutate anything in the genericregistry.Store, and the
self-link is deprecated, unset and not persisted in etcd. There is no
need to do the shallow-copies of metadata any longer.

Signed-off-by: Steve Kuznetsov <skuznets@redhat.com>
---
 .../pkg/registry/customresource/etcd.go       | 57 -------------------
 1 file changed, 57 deletions(-)

diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd.go b/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd.go
index bfbc8b8b14f..8bf451f4d32 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd.go
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd.go
@@ -23,7 +23,6 @@ import (
 
 	autoscalingv1 "k8s.io/api/autoscaling/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
-	metainternalversion "k8s.io/apimachinery/pkg/apis/meta/internalversion"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -118,59 +117,6 @@ func newREST(resource schema.GroupResource, kind, listKind schema.GroupVersionKi
 // Implement CategoriesProvider
 var _ rest.CategoriesProvider = &REST{}
 
-// List returns a list of items matching labels and field according to the store's PredicateFunc.
-func (e *REST) List(ctx context.Context, options *metainternalversion.ListOptions) (runtime.Object, error) {
-	l, err := e.Store.List(ctx, options)
-	if err != nil {
-		return nil, err
-	}
-
-	// Shallow copy ObjectMeta in returned list for each item. Native types have `Items []Item` fields and therefore
-	// implicitly shallow copy ObjectMeta. The generic store sets the self-link for each item. So this is necessary
-	// to avoid mutation of the objects from the cache.
-	if ul, ok := l.(*unstructured.UnstructuredList); ok {
-		for i := range ul.Items {
-			shallowCopyObjectMeta(&ul.Items[i])
-		}
-	}
-
-	return l, nil
-}
-
-func (r *REST) Get(ctx context.Context, name string, options *metav1.GetOptions) (runtime.Object, error) {
-	o, err := r.Store.Get(ctx, name, options)
-	if err != nil {
-		return nil, err
-	}
-	if u, ok := o.(*unstructured.Unstructured); ok {
-		shallowCopyObjectMeta(u)
-	}
-	return o, nil
-}
-
-func shallowCopyObjectMeta(u runtime.Unstructured) {
-	obj := shallowMapDeepCopy(u.UnstructuredContent())
-	if metadata, ok := obj["metadata"]; ok {
-		if metadata, ok := metadata.(map[string]interface{}); ok {
-			obj["metadata"] = shallowMapDeepCopy(metadata)
-			u.SetUnstructuredContent(obj)
-		}
-	}
-}
-
-func shallowMapDeepCopy(in map[string]interface{}) map[string]interface{} {
-	if in == nil {
-		return nil
-	}
-
-	out := make(map[string]interface{}, len(in))
-	for k, v := range in {
-		out[k] = v
-	}
-
-	return out
-}
-
 // Categories implements the CategoriesProvider interface. Returns a list of categories a resource is part of.
 func (r *REST) Categories() []string {
 	return r.categories
@@ -193,9 +139,6 @@ func (r *StatusREST) Get(ctx context.Context, name string, options *metav1.GetOp
 	if err != nil {
 		return nil, err
 	}
-	if u, ok := o.(*unstructured.Unstructured); ok {
-		shallowCopyObjectMeta(u)
-	}
 	return o, nil
 }