mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-26 06:50:23 +00:00
74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
|
/*
|
||
|
|
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
|
||
|
|
}
|