Add k8s ptr

2025-03-23 14:53:03 +08:00
parent 10ebaa1964
commit c99f1306e3
1 changed files with 73 additions and 0 deletions
--- a/pkg/ptr/ptr.go
+++ b/pkg/ptr/ptr.go
@@ -0,0 +1,73 @@
+/* 
+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 ptr 
+ 
+import ( 
+"fmt" 
+"reflect" 
+) 
+ 
+// AllPtrFieldsNil tests whether all pointer fields in a struct are nil. This is useful when, 
+// for example, an API struct is handled by plugins which need to distinguish 
+// "no plugin accepted this spec" from "this spec is empty". 
+// 
+// This function is only valid for structs and pointers to structs. Any other 
+// type will cause a panic. Passing a typed nil pointer will return true. 
+func AllPtrFieldsNil(obj interface{}) bool { 
+v := reflect.ValueOf(obj) 
+if !v.IsValid() { 
+panic(fmt.Sprintf("reflect.ValueOf() produced a non-valid Value for %#v", obj)) 
+} 
+if v.Kind() == reflect.Ptr { 
+if v.IsNil() { 
+return true 
+} 
+v = v.Elem() 
+} 
+for i := 0; i < v.NumField(); i++ { 
+if v.Field(i).Kind() == reflect.Ptr && !v.Field(i).IsNil() { 
+return false 
+} 
+} 
+return true 
+} 
+ 
+// To returns a pointer to the given value. 
+func To[T any](v T) *T { 
+return &v 
+} 
+ 
+// Deref dereferences ptr and returns the value it points to if no nil, or else 
+// returns def. 
+func Deref[T any](ptr *T, def T) T { 
+if ptr != nil { 
+return *ptr 
+} 
+return def 
+} 
+ 
+// Equal returns true if both arguments are nil or both arguments 
+// dereference to the same value. 
+func Equal[T comparable](a, b *T) bool { 
+if (a == nil) != (b == nil) { 
+return false 
+} 
+if a == nil { 
+return true 
+} 
+return *a == *b 
+}