Golang conversion.EnforcePtr函数代码示例

// SetList sets the given list object's Items member have the elements given in
// objects.
// Returns an error if list is not a List type (does not have an Items member),
// or if any of the objects are not of the right type.
func SetList(list runtime.Object, objects []runtime.Object) error {
	itemsPtr, err := GetItemsPtr(list)
	if err != nil {
		return err
	}
	items, err := conversion.EnforcePtr(itemsPtr)
	if err != nil {
		return err
	}
	if items.Type() == objectSliceType {
		items.Set(reflect.ValueOf(objects))
		return nil
	}
	slice := reflect.MakeSlice(items.Type(), len(objects), len(objects))
	for i := range objects {
		dest := slice.Index(i)
		src, err := conversion.EnforcePtr(objects[i])
		if err != nil {
			return err
		}
		if src.Type().AssignableTo(dest.Type()) {
			dest.Set(src)
		} else if src.Type().ConvertibleTo(dest.Type()) {
			dest.Set(src.Convert(dest.Type()))
		} else {
			return fmt.Errorf("item[%d]: can't assign or convert %v into %v", i, src.Type(), dest.Type())
		}
	}
	items.Set(slice)
	return nil
}

// ExtractList returns obj's Items element as an array of runtime.Objects.
// Returns an error if obj is not a List type (does not have an Items member).
func ExtractList(obj runtime.Object) ([]runtime.Object, error) {
	itemsPtr, err := GetItemsPtr(obj)
	if err != nil {
		return nil, err
	}
	items, err := conversion.EnforcePtr(itemsPtr)
	if err != nil {
		return nil, err
	}
	list := make([]runtime.Object, items.Len())
	for i := range list {
		raw := items.Index(i)
		switch item := raw.Interface().(type) {
		case runtime.RawExtension:
			switch {
			case item.Object != nil:
				list[i] = item.Object
			case item.Raw != nil:
				// TODO: Set ContentEncoding and ContentType correctly.
				list[i] = &runtime.Unknown{Raw: item.Raw}
			default:
				list[i] = nil
			}
		case runtime.Object:
			list[i] = item
		default:
			var found bool
			if list[i], found = raw.Addr().Interface().(runtime.Object); !found {
				return nil, fmt.Errorf("%v: item[%v]: Expected object, got %#v(%s)", obj, i, raw.Interface(), raw.Kind())
			}
		}
	}
	return list, nil
}

// SetZeroValue would set the object of objPtr to zero value of its type.
func SetZeroValue(objPtr Object) error {
	v, err := conversion.EnforcePtr(objPtr)
	if err != nil {
		return err
	}
	v.Set(reflect.Zero(v.Type()))
	return nil
}

// ListMetaFor returns a pointer to a provided object's ListMeta,
// or an error if the object does not have that pointer.
// TODO: allow runtime.Unknown to extract this object
func ListMetaFor(obj runtime.Object) (*unversioned.ListMeta, error) {
	v, err := conversion.EnforcePtr(obj)
	if err != nil {
		return nil, err
	}
	var meta *unversioned.ListMeta
	err = runtime.FieldPtr(v, "ListMeta", &meta)
	return meta, err
}

func (s *Scheme) IsUnversioned(obj Object) (bool, bool) {
	v, err := conversion.EnforcePtr(obj)
	if err != nil {
		return false, false
	}
	t := v.Type()

	if _, ok := s.typeToGVK[t]; !ok {
		return false, false
	}
	_, ok := s.unversionedTypes[t]
	return ok, true
}

// ObjectKinds returns all possible group,version,kind of the go object, true if the
// object is considered unversioned, or an error if it's not a pointer or is unregistered.
func (s *Scheme) ObjectKinds(obj Object) ([]unversioned.GroupVersionKind, bool, error) {
	v, err := conversion.EnforcePtr(obj)
	if err != nil {
		return nil, false, err
	}
	t := v.Type()

	gvks, ok := s.typeToGVK[t]
	if !ok {
		return nil, false, NewNotRegisteredErr(unversioned.GroupVersionKind{}, t)
	}
	_, unversionedType := s.unversionedTypes[t]

	return gvks, unversionedType, nil
}

// EachListItem invokes fn on each runtime.Object in the list. Any error immediately terminates
// the loop.
func EachListItem(obj runtime.Object, fn func(runtime.Object) error) error {
	// TODO: Change to an interface call?
	itemsPtr, err := GetItemsPtr(obj)
	if err != nil {
		return err
	}
	items, err := conversion.EnforcePtr(itemsPtr)
	if err != nil {
		return err
	}
	len := items.Len()
	if len == 0 {
		return nil
	}
	takeAddr := false
	if elemType := items.Type().Elem(); elemType.Kind() != reflect.Ptr && elemType.Kind() != reflect.Interface {
		if !items.Index(0).CanAddr() {
			return fmt.Errorf("unable to take address of items in %T for EachListItem", obj)
		}
		takeAddr = true
	}

	for i := 0; i < len; i++ {
		raw := items.Index(i)
		if takeAddr {
			raw = raw.Addr()
		}
		switch item := raw.Interface().(type) {
		case *runtime.RawExtension:
			if err := fn(item.Object); err != nil {
				return err
			}
		case runtime.Object:
			if err := fn(item); err != nil {
				return err
			}
		default:
			obj, ok := item.(runtime.Object)
			if !ok {
				return fmt.Errorf("%v: item[%v]: Expected object, got %#v(%s)", obj, i, raw.Interface(), raw.Kind())
			}
			if err := fn(obj); err != nil {
				return err
			}
		}
	}
	return nil
}

// Field puts the value of fieldName, which must be a member of v, into dest,
// which must be a variable to which this field's value can be assigned.
func Field(v reflect.Value, fieldName string, dest interface{}) error {
	field := v.FieldByName(fieldName)
	if !field.IsValid() {
		return fmt.Errorf("couldn't find %v field in %#v", fieldName, v.Interface())
	}
	destValue, err := conversion.EnforcePtr(dest)
	if err != nil {
		return err
	}
	if field.Type().AssignableTo(destValue.Type()) {
		destValue.Set(field)
		return nil
	}
	if field.Type().ConvertibleTo(destValue.Type()) {
		destValue.Set(field.Convert(destValue.Type()))
		return nil
	}
	return fmt.Errorf("couldn't assign/convert %v to %v", field.Type(), destValue.Type())
}

// GetItemsPtr returns a pointer to the list object's Items member.
// If 'list' doesn't have an Items member, it's not really a list type
// and an error will be returned.
// This function will either return a pointer to a slice, or an error, but not both.
func GetItemsPtr(list runtime.Object) (interface{}, error) {
	v, err := conversion.EnforcePtr(list)
	if err != nil {
		return nil, err
	}
	items := v.FieldByName("Items")
	if !items.IsValid() {
		return nil, fmt.Errorf("no Items field in %#v", list)
	}
	switch items.Kind() {
	case reflect.Interface, reflect.Ptr:
		target := reflect.TypeOf(items.Interface()).Elem()
		if target.Kind() != reflect.Slice {
			return nil, fmt.Errorf("items: Expected slice, got %s", target.Kind())
		}
		return items.Interface(), nil
	case reflect.Slice:
		return items.Addr().Interface(), nil
	default:
		return nil, fmt.Errorf("items: Expected slice, got %s", items.Kind())
	}
}