traefik/vendor/k8s.io/client-go/pkg/runtime/serializer/versioning/versioning.go
2017-04-07 11:52:18 +01:00

265 lines
7.8 KiB
Go

/*
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 versioning
import (
"io"
"k8s.io/client-go/pkg/api/unversioned"
"k8s.io/client-go/pkg/runtime"
utilruntime "k8s.io/client-go/pkg/util/runtime"
)
// NewCodecForScheme is a convenience method for callers that are using a scheme.
func NewCodecForScheme(
// TODO: I should be a scheme interface?
scheme *runtime.Scheme,
encoder runtime.Encoder,
decoder runtime.Decoder,
encodeVersion runtime.GroupVersioner,
decodeVersion runtime.GroupVersioner,
) runtime.Codec {
return NewCodec(encoder, decoder, runtime.UnsafeObjectConvertor(scheme), scheme, scheme, scheme, nil, encodeVersion, decodeVersion)
}
// NewDefaultingCodecForScheme is a convenience method for callers that are using a scheme.
func NewDefaultingCodecForScheme(
// TODO: I should be a scheme interface?
scheme *runtime.Scheme,
encoder runtime.Encoder,
decoder runtime.Decoder,
encodeVersion runtime.GroupVersioner,
decodeVersion runtime.GroupVersioner,
) runtime.Codec {
return NewCodec(encoder, decoder, runtime.UnsafeObjectConvertor(scheme), scheme, scheme, scheme, scheme, encodeVersion, decodeVersion)
}
// NewCodec takes objects in their internal versions and converts them to external versions before
// serializing them. It assumes the serializer provided to it only deals with external versions.
// This class is also a serializer, but is generally used with a specific version.
func NewCodec(
encoder runtime.Encoder,
decoder runtime.Decoder,
convertor runtime.ObjectConvertor,
creater runtime.ObjectCreater,
copier runtime.ObjectCopier,
typer runtime.ObjectTyper,
defaulter runtime.ObjectDefaulter,
encodeVersion runtime.GroupVersioner,
decodeVersion runtime.GroupVersioner,
) runtime.Codec {
internal := &codec{
encoder: encoder,
decoder: decoder,
convertor: convertor,
creater: creater,
copier: copier,
typer: typer,
defaulter: defaulter,
encodeVersion: encodeVersion,
decodeVersion: decodeVersion,
}
return internal
}
type codec struct {
encoder runtime.Encoder
decoder runtime.Decoder
convertor runtime.ObjectConvertor
creater runtime.ObjectCreater
copier runtime.ObjectCopier
typer runtime.ObjectTyper
defaulter runtime.ObjectDefaulter
encodeVersion runtime.GroupVersioner
decodeVersion runtime.GroupVersioner
}
// Decode attempts a decode of the object, then tries to convert it to the internal version. If into is provided and the decoding is
// successful, the returned runtime.Object will be the value passed as into. Note that this may bypass conversion if you pass an
// into that matches the serialized version.
func (c *codec) Decode(data []byte, defaultGVK *unversioned.GroupVersionKind, into runtime.Object) (runtime.Object, *unversioned.GroupVersionKind, error) {
versioned, isVersioned := into.(*runtime.VersionedObjects)
if isVersioned {
into = versioned.Last()
}
obj, gvk, err := c.decoder.Decode(data, defaultGVK, into)
if err != nil {
return nil, gvk, err
}
if d, ok := obj.(runtime.NestedObjectDecoder); ok {
if err := d.DecodeNestedObjects(DirectDecoder{c.decoder}); err != nil {
return nil, gvk, err
}
}
// if we specify a target, use generic conversion.
if into != nil {
if into == obj {
if isVersioned {
return versioned, gvk, nil
}
return into, gvk, nil
}
// perform defaulting if requested
if c.defaulter != nil {
// create a copy to ensure defaulting is not applied to the original versioned objects
if isVersioned {
copied, err := c.copier.Copy(obj)
if err != nil {
utilruntime.HandleError(err)
copied = obj
}
versioned.Objects = []runtime.Object{copied}
}
c.defaulter.Default(obj)
} else {
if isVersioned {
versioned.Objects = []runtime.Object{obj}
}
}
if err := c.convertor.Convert(obj, into, c.decodeVersion); err != nil {
return nil, gvk, err
}
if isVersioned {
versioned.Objects = append(versioned.Objects, into)
return versioned, gvk, nil
}
return into, gvk, nil
}
// Convert if needed.
if isVersioned {
// create a copy, because ConvertToVersion does not guarantee non-mutation of objects
copied, err := c.copier.Copy(obj)
if err != nil {
utilruntime.HandleError(err)
copied = obj
}
versioned.Objects = []runtime.Object{copied}
}
// perform defaulting if requested
if c.defaulter != nil {
c.defaulter.Default(obj)
}
out, err := c.convertor.ConvertToVersion(obj, c.decodeVersion)
if err != nil {
return nil, gvk, err
}
if isVersioned {
if versioned.Last() != out {
versioned.Objects = append(versioned.Objects, out)
}
return versioned, gvk, nil
}
return out, gvk, nil
}
// Encode ensures the provided object is output in the appropriate group and version, invoking
// conversion if necessary. Unversioned objects (according to the ObjectTyper) are output as is.
func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
switch obj.(type) {
case *runtime.Unknown, *runtime.Unstructured, *runtime.UnstructuredList:
return c.encoder.Encode(obj, w)
}
gvks, isUnversioned, err := c.typer.ObjectKinds(obj)
if err != nil {
return err
}
if c.encodeVersion == nil || isUnversioned {
if e, ok := obj.(runtime.NestedObjectEncoder); ok {
if err := e.EncodeNestedObjects(DirectEncoder{Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
return err
}
}
objectKind := obj.GetObjectKind()
old := objectKind.GroupVersionKind()
objectKind.SetGroupVersionKind(gvks[0])
err = c.encoder.Encode(obj, w)
objectKind.SetGroupVersionKind(old)
return err
}
// Perform a conversion if necessary
objectKind := obj.GetObjectKind()
old := objectKind.GroupVersionKind()
out, err := c.convertor.ConvertToVersion(obj, c.encodeVersion)
if err != nil {
return err
}
if e, ok := out.(runtime.NestedObjectEncoder); ok {
if err := e.EncodeNestedObjects(DirectEncoder{Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
return err
}
}
// Conversion is responsible for setting the proper group, version, and kind onto the outgoing object
err = c.encoder.Encode(out, w)
// restore the old GVK, in case conversion returned the same object
objectKind.SetGroupVersionKind(old)
return err
}
// DirectEncoder serializes an object and ensures the GVK is set.
type DirectEncoder struct {
runtime.Encoder
runtime.ObjectTyper
}
// Encode does not do conversion. It sets the gvk during serialization.
func (e DirectEncoder) Encode(obj runtime.Object, stream io.Writer) error {
gvks, _, err := e.ObjectTyper.ObjectKinds(obj)
if err != nil {
if runtime.IsNotRegisteredError(err) {
return e.Encoder.Encode(obj, stream)
}
return err
}
kind := obj.GetObjectKind()
oldGVK := kind.GroupVersionKind()
kind.SetGroupVersionKind(gvks[0])
err = e.Encoder.Encode(obj, stream)
kind.SetGroupVersionKind(oldGVK)
return err
}
// DirectDecoder clears the group version kind of a deserialized object.
type DirectDecoder struct {
runtime.Decoder
}
// Decode does not do conversion. It removes the gvk during deserialization.
func (d DirectDecoder) Decode(data []byte, defaults *unversioned.GroupVersionKind, into runtime.Object) (runtime.Object, *unversioned.GroupVersionKind, error) {
obj, gvk, err := d.Decoder.Decode(data, defaults, into)
if obj != nil {
kind := obj.GetObjectKind()
// clearing the gvk is just a convention of a codec
kind.SetGroupVersionKind(unversioned.GroupVersionKind{})
}
return obj, gvk, err
}