63 lines
1.7 KiB
Go
63 lines
1.7 KiB
Go
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/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package pointer
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import (
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"fmt"
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"reflect"
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)
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// AllPtrFieldsNil tests whether all pointer fields in a struct are nil. This is useful when,
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// for example, an API struct is handled by plugins which need to distinguish
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// "no plugin accepted this spec" from "this spec is empty".
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//
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// This function is only valid for structs and pointers to structs. Any other
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// type will cause a panic. Passing a typed nil pointer will return true.
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func AllPtrFieldsNil(obj interface{}) bool {
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v := reflect.ValueOf(obj)
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if !v.IsValid() {
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panic(fmt.Sprintf("reflect.ValueOf() produced a non-valid Value for %#v", obj))
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}
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if v.Kind() == reflect.Ptr {
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if v.IsNil() {
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return true
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}
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v = v.Elem()
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}
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for i := 0; i < v.NumField(); i++ {
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if v.Field(i).Kind() == reflect.Ptr && !v.Field(i).IsNil() {
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return false
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}
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}
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return true
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}
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// Int32Ptr returns a pointer to an int32
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func Int32Ptr(i int32) *int32 {
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o := i
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return &o
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}
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// Int32PtrDerefOr dereference the int32 ptr and returns it i not nil,
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// else returns def.
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func Int32PtrDerefOr(ptr *int32, def int32) int32 {
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if ptr != nil {
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return *ptr
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}
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return def
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}
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