diff --git a/pointer/pointer.go b/pointer/pointer.go index b8103223..b673a642 100644 --- a/pointer/pointer.go +++ b/pointer/pointer.go @@ -14,12 +14,15 @@ See the License for the specific language governing permissions and limitations under the License. */ +// Deprecated: Use functions in k8s.io/utils/ptr instead: ptr.To to obtain +// a pointer, ptr.Deref to dereference a pointer, ptr.Equal to compare +// dereferenced pointers. package pointer import ( - "fmt" - "reflect" "time" + + "k8s.io/utils/ptr" ) // AllPtrFieldsNil tests whether all pointer fields in a struct are nil. This is useful when, @@ -28,383 +31,219 @@ import ( // // 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 -} - -// Int returns a pointer to an int -func Int(i int) *int { - return &i -} +// +// Deprecated: Use ptr.AllPtrFieldsNil instead. +var AllPtrFieldsNil = ptr.AllPtrFieldsNil + +// Int returns a pointer to an int. +var Int = ptr.To[int] // IntPtr is a function variable referring to Int. // -// Deprecated: Use Int instead. +// Deprecated: Use ptr.To instead. var IntPtr = Int // for back-compat // IntDeref dereferences the int ptr and returns it if not nil, or else // returns def. -func IntDeref(ptr *int, def int) int { - if ptr != nil { - return *ptr - } - return def -} +var IntDeref = ptr.Deref[int] // IntPtrDerefOr is a function variable referring to IntDeref. // -// Deprecated: Use IntDeref instead. +// Deprecated: Use ptr.Deref instead. var IntPtrDerefOr = IntDeref // for back-compat // Int32 returns a pointer to an int32. -func Int32(i int32) *int32 { - return &i -} +var Int32 = ptr.To[int32] // Int32Ptr is a function variable referring to Int32. // -// Deprecated: Use Int32 instead. +// Deprecated: Use ptr.To instead. var Int32Ptr = Int32 // for back-compat // Int32Deref dereferences the int32 ptr and returns it if not nil, or else // returns def. -func Int32Deref(ptr *int32, def int32) int32 { - if ptr != nil { - return *ptr - } - return def -} +var Int32Deref = ptr.Deref[int32] // Int32PtrDerefOr is a function variable referring to Int32Deref. // -// Deprecated: Use Int32Deref instead. +// Deprecated: Use ptr.Deref instead. var Int32PtrDerefOr = Int32Deref // for back-compat // Int32Equal returns true if both arguments are nil or both arguments // dereference to the same value. -func Int32Equal(a, b *int32) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var Int32Equal = ptr.Equal[int32] // Uint returns a pointer to an uint -func Uint(i uint) *uint { - return &i -} +var Uint = ptr.To[uint] // UintPtr is a function variable referring to Uint. // -// Deprecated: Use Uint instead. +// Deprecated: Use ptr.To instead. var UintPtr = Uint // for back-compat // UintDeref dereferences the uint ptr and returns it if not nil, or else // returns def. -func UintDeref(ptr *uint, def uint) uint { - if ptr != nil { - return *ptr - } - return def -} +var UintDeref = ptr.Deref[uint] // UintPtrDerefOr is a function variable referring to UintDeref. // -// Deprecated: Use UintDeref instead. +// Deprecated: Use ptr.Deref instead. var UintPtrDerefOr = UintDeref // for back-compat // Uint32 returns a pointer to an uint32. -func Uint32(i uint32) *uint32 { - return &i -} +var Uint32 = ptr.To[uint32] // Uint32Ptr is a function variable referring to Uint32. // -// Deprecated: Use Uint32 instead. +// Deprecated: Use ptr.To instead. var Uint32Ptr = Uint32 // for back-compat // Uint32Deref dereferences the uint32 ptr and returns it if not nil, or else // returns def. -func Uint32Deref(ptr *uint32, def uint32) uint32 { - if ptr != nil { - return *ptr - } - return def -} +var Uint32Deref = ptr.Deref[uint32] // Uint32PtrDerefOr is a function variable referring to Uint32Deref. // -// Deprecated: Use Uint32Deref instead. +// Deprecated: Use ptr.Deref instead. var Uint32PtrDerefOr = Uint32Deref // for back-compat // Uint32Equal returns true if both arguments are nil or both arguments // dereference to the same value. -func Uint32Equal(a, b *uint32) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var Uint32Equal = ptr.Equal[uint32] // Int64 returns a pointer to an int64. -func Int64(i int64) *int64 { - return &i -} +var Int64 = ptr.To[int64] // Int64Ptr is a function variable referring to Int64. // -// Deprecated: Use Int64 instead. +// Deprecated: Use ptr.To instead. var Int64Ptr = Int64 // for back-compat // Int64Deref dereferences the int64 ptr and returns it if not nil, or else // returns def. -func Int64Deref(ptr *int64, def int64) int64 { - if ptr != nil { - return *ptr - } - return def -} +var Int64Deref = ptr.Deref[int64] // Int64PtrDerefOr is a function variable referring to Int64Deref. // -// Deprecated: Use Int64Deref instead. +// Deprecated: Use ptr.Deref instead. var Int64PtrDerefOr = Int64Deref // for back-compat // Int64Equal returns true if both arguments are nil or both arguments // dereference to the same value. -func Int64Equal(a, b *int64) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var Int64Equal = ptr.Equal[int64] // Uint64 returns a pointer to an uint64. -func Uint64(i uint64) *uint64 { - return &i -} +var Uint64 = ptr.To[uint64] // Uint64Ptr is a function variable referring to Uint64. // -// Deprecated: Use Uint64 instead. +// Deprecated: Use ptr.To instead. var Uint64Ptr = Uint64 // for back-compat // Uint64Deref dereferences the uint64 ptr and returns it if not nil, or else // returns def. -func Uint64Deref(ptr *uint64, def uint64) uint64 { - if ptr != nil { - return *ptr - } - return def -} +var Uint64Deref = ptr.Deref[uint64] // Uint64PtrDerefOr is a function variable referring to Uint64Deref. // -// Deprecated: Use Uint64Deref instead. +// Deprecated: Use ptr.Deref instead. var Uint64PtrDerefOr = Uint64Deref // for back-compat // Uint64Equal returns true if both arguments are nil or both arguments // dereference to the same value. -func Uint64Equal(a, b *uint64) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var Uint64Equal = ptr.Equal[uint64] // Bool returns a pointer to a bool. -func Bool(b bool) *bool { - return &b -} +var Bool = ptr.To[bool] // BoolPtr is a function variable referring to Bool. // -// Deprecated: Use Bool instead. +// Deprecated: Use ptr.To instead. var BoolPtr = Bool // for back-compat // BoolDeref dereferences the bool ptr and returns it if not nil, or else // returns def. -func BoolDeref(ptr *bool, def bool) bool { - if ptr != nil { - return *ptr - } - return def -} +var BoolDeref = ptr.Deref[bool] // BoolPtrDerefOr is a function variable referring to BoolDeref. // -// Deprecated: Use BoolDeref instead. +// Deprecated: Use ptr.Deref instead. var BoolPtrDerefOr = BoolDeref // for back-compat // BoolEqual returns true if both arguments are nil or both arguments // dereference to the same value. -func BoolEqual(a, b *bool) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var BoolEqual = ptr.Equal[bool] // String returns a pointer to a string. -func String(s string) *string { - return &s -} +var String = ptr.To[string] // StringPtr is a function variable referring to String. // -// Deprecated: Use String instead. +// Deprecated: Use ptr.To instead. var StringPtr = String // for back-compat // StringDeref dereferences the string ptr and returns it if not nil, or else // returns def. -func StringDeref(ptr *string, def string) string { - if ptr != nil { - return *ptr - } - return def -} +var StringDeref = ptr.Deref[string] // StringPtrDerefOr is a function variable referring to StringDeref. // -// Deprecated: Use StringDeref instead. +// Deprecated: Use ptr.Deref instead. var StringPtrDerefOr = StringDeref // for back-compat // StringEqual returns true if both arguments are nil or both arguments // dereference to the same value. -func StringEqual(a, b *string) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var StringEqual = ptr.Equal[string] // Float32 returns a pointer to a float32. -func Float32(i float32) *float32 { - return &i -} +var Float32 = ptr.To[float32] // Float32Ptr is a function variable referring to Float32. // -// Deprecated: Use Float32 instead. +// Deprecated: Use ptr.To instead. var Float32Ptr = Float32 // Float32Deref dereferences the float32 ptr and returns it if not nil, or else // returns def. -func Float32Deref(ptr *float32, def float32) float32 { - if ptr != nil { - return *ptr - } - return def -} +var Float32Deref = ptr.Deref[float32] // Float32PtrDerefOr is a function variable referring to Float32Deref. // -// Deprecated: Use Float32Deref instead. +// Deprecated: Use ptr.Deref instead. var Float32PtrDerefOr = Float32Deref // for back-compat // Float32Equal returns true if both arguments are nil or both arguments // dereference to the same value. -func Float32Equal(a, b *float32) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var Float32Equal = ptr.Equal[float32] // Float64 returns a pointer to a float64. -func Float64(i float64) *float64 { - return &i -} +var Float64 = ptr.To[float64] // Float64Ptr is a function variable referring to Float64. // -// Deprecated: Use Float64 instead. +// Deprecated: Use ptr.To instead. var Float64Ptr = Float64 // Float64Deref dereferences the float64 ptr and returns it if not nil, or else // returns def. -func Float64Deref(ptr *float64, def float64) float64 { - if ptr != nil { - return *ptr - } - return def -} +var Float64Deref = ptr.Deref[float64] // Float64PtrDerefOr is a function variable referring to Float64Deref. // -// Deprecated: Use Float64Deref instead. +// Deprecated: Use ptr.Deref instead. var Float64PtrDerefOr = Float64Deref // for back-compat // Float64Equal returns true if both arguments are nil or both arguments // dereference to the same value. -func Float64Equal(a, b *float64) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var Float64Equal = ptr.Equal[float64] // Duration returns a pointer to a time.Duration. -func Duration(d time.Duration) *time.Duration { - return &d -} +var Duration = ptr.To[time.Duration] // DurationDeref dereferences the time.Duration ptr and returns it if not nil, or else // returns def. -func DurationDeref(ptr *time.Duration, def time.Duration) time.Duration { - if ptr != nil { - return *ptr - } - return def -} +var DurationDeref = ptr.Deref[time.Duration] // DurationEqual returns true if both arguments are nil or both arguments // dereference to the same value. -func DurationEqual(a, b *time.Duration) bool { - if (a == nil) != (b == nil) { - return false - } - if a == nil { - return true - } - return *a == *b -} +var DurationEqual = ptr.Equal[time.Duration] diff --git a/ptr/OWNERS b/ptr/OWNERS new file mode 100644 index 00000000..0d639275 --- /dev/null +++ b/ptr/OWNERS @@ -0,0 +1,10 @@ +# See the OWNERS docs at https://go.k8s.io/owners + +approvers: +- apelisse +- stewart-yu +- thockin +reviewers: +- apelisse +- stewart-yu +- thockin diff --git a/ptr/README.md b/ptr/README.md new file mode 100644 index 00000000..2ca8073d --- /dev/null +++ b/ptr/README.md @@ -0,0 +1,3 @@ +# Pointer + +This package provides some functions for pointer-based operations. diff --git a/ptr/ptr.go b/ptr/ptr.go new file mode 100644 index 00000000..659ed3b9 --- /dev/null +++ b/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 +} diff --git a/ptr/ptr_test.go b/ptr/ptr_test.go new file mode 100644 index 00000000..046d8967 --- /dev/null +++ b/ptr/ptr_test.go @@ -0,0 +1,124 @@ +/* +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_test + +import ( + "fmt" + "testing" + + "k8s.io/utils/ptr" +) + +func TestAllPtrFieldsNil(t *testing.T) { + testCases := []struct { + obj interface{} + expected bool + }{ + {struct{}{}, true}, + {struct{ Foo int }{12345}, true}, + {&struct{ Foo int }{12345}, true}, + {struct{ Foo *int }{nil}, true}, + {&struct{ Foo *int }{nil}, true}, + {struct { + Foo int + Bar *int + }{12345, nil}, true}, + {&struct { + Foo int + Bar *int + }{12345, nil}, true}, + {struct { + Foo *int + Bar *int + }{nil, nil}, true}, + {&struct { + Foo *int + Bar *int + }{nil, nil}, true}, + {struct{ Foo *int }{new(int)}, false}, + {&struct{ Foo *int }{new(int)}, false}, + {struct { + Foo *int + Bar *int + }{nil, new(int)}, false}, + {&struct { + Foo *int + Bar *int + }{nil, new(int)}, false}, + {(*struct{})(nil), true}, + } + for i, tc := range testCases { + name := fmt.Sprintf("case[%d]", i) + t.Run(name, func(t *testing.T) { + if actual := ptr.AllPtrFieldsNil(tc.obj); actual != tc.expected { + t.Errorf("%s: expected %t, got %t", name, tc.expected, actual) + } + }) + } +} + +func TestRef(t *testing.T) { + type T int + + val := T(0) + pointer := ptr.To(val) + if *pointer != val { + t.Errorf("expected %d, got %d", val, *pointer) + } + + val = T(1) + pointer = ptr.To(val) + if *pointer != val { + t.Errorf("expected %d, got %d", val, *pointer) + } +} + +func TestDeref(t *testing.T) { + type T int + + var val, def T = 1, 0 + + out := ptr.Deref(&val, def) + if out != val { + t.Errorf("expected %d, got %d", val, out) + } + + out = ptr.Deref(nil, def) + if out != def { + t.Errorf("expected %d, got %d", def, out) + } +} + +func TestEqual(t *testing.T) { + type T int + + if !ptr.Equal[T](nil, nil) { + t.Errorf("expected true (nil == nil)") + } + if !ptr.Equal(ptr.To(T(123)), ptr.To(T(123))) { + t.Errorf("expected true (val == val)") + } + if ptr.Equal(nil, ptr.To(T(123))) { + t.Errorf("expected false (nil != val)") + } + if ptr.Equal(ptr.To(T(123)), nil) { + t.Errorf("expected false (val != nil)") + } + if ptr.Equal(ptr.To(T(123)), ptr.To(T(456))) { + t.Errorf("expected false (val != val)") + } +}