Move DirectEncoder to runtime, add `.WithoutConversion()` on CodecFactory

Renome the Direct*coders to clearly identify what they do - add or remove
the version information while encoding or decoding.

This refactor makes it easier for clients to move to a "no conversion"
model.

staging/src/k8s.io/apimachinery/pkg/runtime/helper.go

@@ -210,3 +210,50 @@ type defaultFramer struct{}
 
 func (defaultFramer) NewFrameReader(r io.ReadCloser) io.ReadCloser { return r }
 func (defaultFramer) NewFrameWriter(w io.Writer) io.Writer         { return w }
+
+// WithVersionEncoder serializes an object and ensures the GVK is set.
+type WithVersionEncoder struct {
+	Version GroupVersioner
+	Encoder
+	ObjectTyper
+}
+
+// Encode does not do conversion. It sets the gvk during serialization.
+func (e WithVersionEncoder) Encode(obj Object, stream io.Writer) error {
+	gvks, _, err := e.ObjectTyper.ObjectKinds(obj)
+	if err != nil {
+		if IsNotRegisteredError(err) {
+			return e.Encoder.Encode(obj, stream)
+		}
+		return err
+	}
+	kind := obj.GetObjectKind()
+	oldGVK := kind.GroupVersionKind()
+	gvk := gvks[0]
+	if e.Version != nil {
+		preferredGVK, ok := e.Version.KindForGroupVersionKinds(gvks)
+		if ok {
+			gvk = preferredGVK
+		}
+	}
+	kind.SetGroupVersionKind(gvk)
+	err = e.Encoder.Encode(obj, stream)
+	kind.SetGroupVersionKind(oldGVK)
+	return err
+}
+
+// WithoutVersionDecoder clears the group version kind of a deserialized object.
+type WithoutVersionDecoder struct {
+	Decoder
+}
+
+// Decode does not do conversion. It removes the gvk during deserialization.
+func (d WithoutVersionDecoder) Decode(data []byte, defaults *schema.GroupVersionKind, into Object) (Object, *schema.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(schema.GroupVersionKind{})
+	}
+	return obj, gvk, err
+}

staging/src/k8s.io/apimachinery/pkg/runtime/serializer/codec_factory.go

@@ -160,6 +160,12 @@ func newCodecFactory(scheme *runtime.Scheme, serializers []serializerType) Codec
 	}
 }
 
+// WithoutConversion returns a NegotiatedSerializer that performs no conversion, even if the
+// caller requests it.
+func (f CodecFactory) WithoutConversion() runtime.NegotiatedSerializer {
+	return WithoutConversionCodecFactory{f}
+}
+
 // SupportedMediaTypes returns the RFC2046 media types that this factory has serializers for.
 func (f CodecFactory) SupportedMediaTypes() []runtime.SerializerInfo {
 	return f.accepts
@@ -227,23 +233,26 @@ func (f CodecFactory) EncoderForVersion(encoder runtime.Encoder, gv runtime.Grou
 	return f.CodecForVersions(encoder, nil, gv, nil)
 }
 
-// DirectCodecFactory provides methods for retrieving "DirectCodec"s, which do not do conversion.
-type DirectCodecFactory struct {
+// WithoutConversionCodecFactory is a CodecFactory that will explicitly ignore requests to perform conversion.
+// This wrapper is used while code migrates away from using conversion (such as external clients) and in the future
+// will be unnecessary when we change the signature of NegotiatedSerializer.
+type WithoutConversionCodecFactory struct {
 	CodecFactory
 }
 
-// EncoderForVersion returns an encoder that does not do conversion.
-func (f DirectCodecFactory) EncoderForVersion(serializer runtime.Encoder, version runtime.GroupVersioner) runtime.Encoder {
-	return versioning.DirectEncoder{
+// EncoderForVersion returns an encoder that does not do conversion, but does set the group version kind of the object
+// when serialized.
+func (f WithoutConversionCodecFactory) EncoderForVersion(serializer runtime.Encoder, version runtime.GroupVersioner) runtime.Encoder {
+	return runtime.WithVersionEncoder{
 		Version:     version,
 		Encoder:     serializer,
 		ObjectTyper: f.CodecFactory.scheme,
 	}
 }
 
-// DecoderToVersion returns an decoder that does not do conversion. gv is ignored.
-func (f DirectCodecFactory) DecoderToVersion(serializer runtime.Decoder, _ runtime.GroupVersioner) runtime.Decoder {
-	return versioning.DirectDecoder{
+// DecoderToVersion returns an decoder that does not do conversion.
+func (f WithoutConversionCodecFactory) DecoderToVersion(serializer runtime.Decoder, _ runtime.GroupVersioner) runtime.Decoder {
+	return runtime.WithoutVersionDecoder{
 		Decoder: serializer,
 	}
 }

staging/src/k8s.io/apimachinery/pkg/runtime/serializer/versioning/versioning.go

@@ -106,7 +106,7 @@ func (c *codec) Decode(data []byte, defaultGVK *schema.GroupVersionKind, into ru
 	}
 
 	if d, ok := obj.(runtime.NestedObjectDecoder); ok {
-		if err := d.DecodeNestedObjects(DirectDecoder{c.decoder}); err != nil {
+		if err := d.DecodeNestedObjects(runtime.WithoutVersionDecoder{c.decoder}); err != nil {
 			return nil, gvk, err
 		}
 	}
@@ -201,7 +201,7 @@ func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
 
 	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 {
+			if err := e.EncodeNestedObjects(runtime.WithVersionEncoder{Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
 				return err
 			}
 		}
@@ -222,7 +222,7 @@ func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
 	}
 
 	if e, ok := out.(runtime.NestedObjectEncoder); ok {
-		if err := e.EncodeNestedObjects(DirectEncoder{Version: c.encodeVersion, Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
+		if err := e.EncodeNestedObjects(runtime.WithVersionEncoder{Version: c.encodeVersion, Encoder: c.encoder, ObjectTyper: c.typer}); err != nil {
 			return err
 		}
 	}
@@ -234,49 +234,8 @@ func (c *codec) Encode(obj runtime.Object, w io.Writer) error {
 	return err
 }
 
-// DirectEncoder serializes an object and ensures the GVK is set.
-type DirectEncoder struct {
-	Version runtime.GroupVersioner
-	runtime.Encoder
-	runtime.ObjectTyper
-}
+// DirectEncoder was movend and renamed in 1.15 and will be removed in 1.16.
+type DirectEncoder = runtime.WithVersionEncoder
 
-// 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()
-	gvk := gvks[0]
-	if e.Version != nil {
-		preferredGVK, ok := e.Version.KindForGroupVersionKinds(gvks)
-		if ok {
-			gvk = preferredGVK
-		}
-	}
-	kind.SetGroupVersionKind(gvk)
-	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 *schema.GroupVersionKind, into runtime.Object) (runtime.Object, *schema.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(schema.GroupVersionKind{})
-	}
-	return obj, gvk, err
-}
+// DirectDecoder was movend and renamed in 1.15 and will be removed in 1.16.
+type DirectDecoder = runtime.WithoutVersionDecoder

staging/src/k8s.io/apimachinery/pkg/runtime/serializer/versioning/versioning_test.go

@@ -370,7 +370,7 @@ func TestDirectCodecEncode(t *testing.T) {
 		},
 	}
 
-	c := DirectEncoder{
+	c := runtime.WithVersionEncoder{
 		Version:     schema.GroupVersion{Group: "expected_group"},
 		Encoder:     &serializer,
 		ObjectTyper: &typer,