diff options
Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/conversion/cloner.go')
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/conversion/cloner.go | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/conversion/cloner.go b/vendor/k8s.io/apimachinery/pkg/conversion/cloner.go new file mode 100644 index 000000000..c5dec1f31 --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/conversion/cloner.go @@ -0,0 +1,249 @@ +/* +Copyright 2014 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 conversion + +import ( + "fmt" + "reflect" +) + +// Cloner knows how to copy one type to another. +type Cloner struct { + // Map from the type to a function which can do the deep copy. + deepCopyFuncs map[reflect.Type]reflect.Value + generatedDeepCopyFuncs map[reflect.Type]func(in interface{}, out interface{}, c *Cloner) error +} + +// NewCloner creates a new Cloner object. +func NewCloner() *Cloner { + c := &Cloner{ + deepCopyFuncs: map[reflect.Type]reflect.Value{}, + generatedDeepCopyFuncs: map[reflect.Type]func(in interface{}, out interface{}, c *Cloner) error{}, + } + if err := c.RegisterDeepCopyFunc(byteSliceDeepCopy); err != nil { + // If one of the deep-copy functions is malformed, detect it immediately. + panic(err) + } + return c +} + +// Prevent recursing into every byte... +func byteSliceDeepCopy(in *[]byte, out *[]byte, c *Cloner) error { + if *in != nil { + *out = make([]byte, len(*in)) + copy(*out, *in) + } else { + *out = nil + } + return nil +} + +// Verifies whether a deep-copy function has a correct signature. +func verifyDeepCopyFunctionSignature(ft reflect.Type) error { + if ft.Kind() != reflect.Func { + return fmt.Errorf("expected func, got: %v", ft) + } + if ft.NumIn() != 3 { + return fmt.Errorf("expected three 'in' params, got %v", ft) + } + if ft.NumOut() != 1 { + return fmt.Errorf("expected one 'out' param, got %v", ft) + } + if ft.In(0).Kind() != reflect.Ptr { + return fmt.Errorf("expected pointer arg for 'in' param 0, got: %v", ft) + } + if ft.In(1) != ft.In(0) { + return fmt.Errorf("expected 'in' param 0 the same as param 1, got: %v", ft) + } + var forClonerType Cloner + if expected := reflect.TypeOf(&forClonerType); ft.In(2) != expected { + return fmt.Errorf("expected '%v' arg for 'in' param 2, got: '%v'", expected, ft.In(2)) + } + var forErrorType error + // This convolution is necessary, otherwise TypeOf picks up on the fact + // that forErrorType is nil + errorType := reflect.TypeOf(&forErrorType).Elem() + if ft.Out(0) != errorType { + return fmt.Errorf("expected error return, got: %v", ft) + } + return nil +} + +// RegisterGeneratedDeepCopyFunc registers a copying func with the Cloner. +// deepCopyFunc must take three parameters: a type input, a pointer to a +// type output, and a pointer to Cloner. It should return an error. +// +// Example: +// c.RegisterGeneratedDeepCopyFunc( +// func(in Pod, out *Pod, c *Cloner) error { +// // deep copy logic... +// return nil +// }) +func (c *Cloner) RegisterDeepCopyFunc(deepCopyFunc interface{}) error { + fv := reflect.ValueOf(deepCopyFunc) + ft := fv.Type() + if err := verifyDeepCopyFunctionSignature(ft); err != nil { + return err + } + c.deepCopyFuncs[ft.In(0)] = fv + return nil +} + +// GeneratedDeepCopyFunc bundles an untyped generated deep-copy function of a type +// with a reflection type object used as a key to lookup the deep-copy function. +type GeneratedDeepCopyFunc struct { + Fn func(in interface{}, out interface{}, c *Cloner) error + InType reflect.Type +} + +// Similar to RegisterDeepCopyFunc, but registers deep copy function that were +// automatically generated. +func (c *Cloner) RegisterGeneratedDeepCopyFunc(fn GeneratedDeepCopyFunc) error { + c.generatedDeepCopyFuncs[fn.InType] = fn.Fn + return nil +} + +// DeepCopy will perform a deep copy of a given object. +func (c *Cloner) DeepCopy(in interface{}) (interface{}, error) { + // Can be invalid if we run DeepCopy(X) where X is a nil interface type. + // For example, we get an invalid value when someone tries to deep-copy + // a nil labels.Selector. + // This does not occur if X is nil and is a pointer to a concrete type. + if in == nil { + return nil, nil + } + inValue := reflect.ValueOf(in) + outValue, err := c.deepCopy(inValue) + if err != nil { + return nil, err + } + return outValue.Interface(), nil +} + +func (c *Cloner) deepCopy(src reflect.Value) (reflect.Value, error) { + inType := src.Type() + + switch src.Kind() { + case reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice: + if src.IsNil() { + return src, nil + } + } + + if fv, ok := c.deepCopyFuncs[inType]; ok { + return c.customDeepCopy(src, fv) + } + if fv, ok := c.generatedDeepCopyFuncs[inType]; ok { + var outValue reflect.Value + outValue = reflect.New(inType.Elem()) + err := fv(src.Interface(), outValue.Interface(), c) + return outValue, err + } + return c.defaultDeepCopy(src) +} + +func (c *Cloner) customDeepCopy(src, fv reflect.Value) (reflect.Value, error) { + outValue := reflect.New(src.Type().Elem()) + args := []reflect.Value{src, outValue, reflect.ValueOf(c)} + result := fv.Call(args)[0].Interface() + // This convolution is necessary because nil interfaces won't convert + // to error. + if result == nil { + return outValue, nil + } + return outValue, result.(error) +} + +func (c *Cloner) defaultDeepCopy(src reflect.Value) (reflect.Value, error) { + switch src.Kind() { + case reflect.Chan, reflect.Func, reflect.UnsafePointer, reflect.Uintptr: + return src, fmt.Errorf("cannot deep copy kind: %s", src.Kind()) + case reflect.Array: + dst := reflect.New(src.Type()) + for i := 0; i < src.Len(); i++ { + copyVal, err := c.deepCopy(src.Index(i)) + if err != nil { + return src, err + } + dst.Elem().Index(i).Set(copyVal) + } + return dst.Elem(), nil + case reflect.Interface: + if src.IsNil() { + return src, nil + } + return c.deepCopy(src.Elem()) + case reflect.Map: + if src.IsNil() { + return src, nil + } + dst := reflect.MakeMap(src.Type()) + for _, k := range src.MapKeys() { + copyVal, err := c.deepCopy(src.MapIndex(k)) + if err != nil { + return src, err + } + dst.SetMapIndex(k, copyVal) + } + return dst, nil + case reflect.Ptr: + if src.IsNil() { + return src, nil + } + dst := reflect.New(src.Type().Elem()) + copyVal, err := c.deepCopy(src.Elem()) + if err != nil { + return src, err + } + dst.Elem().Set(copyVal) + return dst, nil + case reflect.Slice: + if src.IsNil() { + return src, nil + } + dst := reflect.MakeSlice(src.Type(), 0, src.Len()) + for i := 0; i < src.Len(); i++ { + copyVal, err := c.deepCopy(src.Index(i)) + if err != nil { + return src, err + } + dst = reflect.Append(dst, copyVal) + } + return dst, nil + case reflect.Struct: + dst := reflect.New(src.Type()) + for i := 0; i < src.NumField(); i++ { + if !dst.Elem().Field(i).CanSet() { + // Can't set private fields. At this point, the + // best we can do is a shallow copy. For + // example, time.Time is a value type with + // private members that can be shallow copied. + return src, nil + } + copyVal, err := c.deepCopy(src.Field(i)) + if err != nil { + return src, err + } + dst.Elem().Field(i).Set(copyVal) + } + return dst.Elem(), nil + + default: + // Value types like numbers, booleans, and strings. + return src, nil + } +} |