Golang recognizer.NewDecoder函數代碼示例

func TestRecognizer(t *testing.T) {
	s := runtime.NewScheme()
	s.AddKnownTypes(schema.GroupVersion{Version: "v1"}, &A{})
	d := recognizer.NewDecoder(
		json.NewSerializer(json.DefaultMetaFactory, s, s, false),
		json.NewYAMLSerializer(json.DefaultMetaFactory, s, s),
	)
	out, _, err := d.Decode([]byte(`
kind: A
apiVersion: v1
`), nil, nil)
	if err != nil {
		t.Fatal(err)
	}
	t.Logf("%#v", out)

	out, _, err = d.Decode([]byte(`
{
  "kind":"A",
  "apiVersion":"v1"
}
`), nil, nil)
	if err != nil {
		t.Fatal(err)
	}
	t.Logf("%#v", out)
}

// NewStorageCodec assembles a storage codec for the provided storage media type, the provided serializer, and the requested
// storage and memory versions.
func NewStorageCodec(storageMediaType string, ns runtime.StorageSerializer, storageVersion, memoryVersion unversioned.GroupVersion, config storagebackend.Config) (runtime.Codec, error) {
	mediaType, options, err := mime.ParseMediaType(storageMediaType)
	if err != nil {
		return nil, fmt.Errorf("%q is not a valid mime-type", storageMediaType)
	}
	serializer, ok := ns.SerializerForMediaType(mediaType, options)
	if !ok {
		return nil, fmt.Errorf("unable to find serializer for %q", storageMediaType)
	}

	s := serializer.Serializer

	// etcd2 only supports string data - we must wrap any result before returning
	// TODO: storagebackend should return a boolean indicating whether it supports binary data
	if !serializer.EncodesAsText && (config.Type == storagebackend.StorageTypeUnset || config.Type == storagebackend.StorageTypeETCD2) {
		glog.V(4).Infof("Wrapping the underlying binary storage serializer with a base64 encoding for etcd2")
		s = runtime.NewBase64Serializer(s)
	}

	ds := recognizer.NewDecoder(s, ns.UniversalDeserializer())
	encoder := ns.EncoderForVersion(s, storageVersion)
	decoder := ns.DecoderToVersion(ds, memoryVersion)
	if memoryVersion.Group != storageVersion.Group {
		// Allow this codec to translate between groups.
		if err := versioning.EnableCrossGroupEncoding(encoder, memoryVersion.Group, storageVersion.Group); err != nil {
			return nil, fmt.Errorf("error setting up encoder from %v to %v: %v", memoryVersion, storageVersion, err)
		}
		if err := versioning.EnableCrossGroupDecoding(decoder, storageVersion.Group, memoryVersion.Group); err != nil {
			return nil, fmt.Errorf("error setting up decoder from %v to %v: %v", storageVersion, memoryVersion, err)
		}
	}
	return runtime.NewCodec(encoder, decoder), nil
}

// newCodecFactory is a helper for testing that allows a different metafactory to be specified.
func newCodecFactory(scheme *runtime.Scheme, serializers []serializerType) CodecFactory {
	decoders := make([]runtime.Decoder, 0, len(serializers))
	accepts := []string{}
	alreadyAccepted := make(map[string]struct{})
	var legacySerializer runtime.Serializer
	for _, d := range serializers {
		decoders = append(decoders, d.Serializer)
		for _, mediaType := range d.AcceptContentTypes {
			if _, ok := alreadyAccepted[mediaType]; ok {
				continue
			}
			alreadyAccepted[mediaType] = struct{}{}
			accepts = append(accepts, mediaType)
			if mediaType == "application/json" {
				legacySerializer = d.Serializer
			}
		}
	}
	if legacySerializer == nil {
		legacySerializer = serializers[0].Serializer
	}
	return CodecFactory{
		scheme:      scheme,
		serializers: serializers,
		universal:   recognizer.NewDecoder(decoders...),
		accepts:     accepts,

		legacySerializer: legacySerializer,
	}
}

// StorageCodec returns the codec for the API version to store in etcd, as set by the
// KUBE_TEST_API_STORAGE_TYPE env var.
func (g TestGroup) StorageCodec() runtime.Codec {
	s := storageSerializer.Serializer

	if s == nil {
		return api.Codecs.LegacyCodec(g.externalGroupVersion)
	}

	// etcd2 only supports string data - we must wrap any result before returning
	// TODO: remove for etcd3 / make parameterizable
	if !storageSerializer.EncodesAsText {
		s = runtime.NewBase64Serializer(s)
	}
	ds := recognizer.NewDecoder(s, api.Codecs.UniversalDeserializer())

	return api.Codecs.CodecForVersions(s, ds, unversioned.GroupVersions{g.externalGroupVersion}, nil)
}

// newCodecFactory is a helper for testing that allows a different metafactory to be specified.
func newCodecFactory(scheme *runtime.Scheme, serializers []serializerType) CodecFactory {
	decoders := make([]runtime.Decoder, 0, len(serializers))
	var accepts []runtime.SerializerInfo
	alreadyAccepted := make(map[string]struct{})

	var legacySerializer runtime.Serializer
	for _, d := range serializers {
		decoders = append(decoders, d.Serializer)
		for _, mediaType := range d.AcceptContentTypes {
			if _, ok := alreadyAccepted[mediaType]; ok {
				continue
			}
			alreadyAccepted[mediaType] = struct{}{}
			info := runtime.SerializerInfo{
				MediaType:        d.ContentType,
				EncodesAsText:    d.EncodesAsText,
				Serializer:       d.Serializer,
				PrettySerializer: d.PrettySerializer,
			}
			if d.StreamSerializer != nil {
				info.StreamSerializer = &runtime.StreamSerializerInfo{
					Serializer:    d.StreamSerializer,
					EncodesAsText: d.EncodesAsText,
					Framer:        d.Framer,
				}
			}
			accepts = append(accepts, info)
			if mediaType == runtime.ContentTypeJSON {
				legacySerializer = d.Serializer
			}
		}
	}
	if legacySerializer == nil {
		legacySerializer = serializers[0].Serializer
	}

	return CodecFactory{
		scheme:      scheme,
		serializers: serializers,
		universal:   recognizer.NewDecoder(decoders...),

		accepts: accepts,

		legacySerializer: legacySerializer,
	}
}

// newCodecFactory is a helper for testing that allows a different metafactory to be specified.
func newCodecFactory(scheme *runtime.Scheme, mf json.MetaFactory) CodecFactory {
	jsonSerializer := json.NewSerializer(mf, scheme, runtime.ObjectTyperToTyper(scheme), false)
	jsonPrettySerializer := json.NewSerializer(mf, scheme, runtime.ObjectTyperToTyper(scheme), true)
	yamlSerializer := json.NewYAMLSerializer(mf, scheme, runtime.ObjectTyperToTyper(scheme))
	serializers := []serializerType{
		{
			AcceptContentTypes: []string{"application/json"},
			ContentType:        "application/json",
			FileExtensions:     []string{"json"},
			Serializer:         jsonSerializer,
			PrettySerializer:   jsonPrettySerializer,
		},
		{
			AcceptContentTypes: []string{"application/yaml"},
			ContentType:        "application/yaml",
			FileExtensions:     []string{"yaml"},
			Serializer:         yamlSerializer,
		},
	}
	decoders := make([]runtime.Decoder, 0, len(serializers))
	accepts := []string{}
	alreadyAccepted := make(map[string]struct{})
	for _, d := range serializers {
		decoders = append(decoders, d.Serializer)
		for _, mediaType := range d.AcceptContentTypes {
			if _, ok := alreadyAccepted[mediaType]; ok {
				continue
			}
			alreadyAccepted[mediaType] = struct{}{}
			accepts = append(accepts, mediaType)
		}
	}
	return CodecFactory{
		scheme:      scheme,
		serializers: serializers,
		universal:   recognizer.NewDecoder(decoders...),
		accepts:     accepts,

		legacySerializer: jsonSerializer,
	}
}

// NewStorageCodec assembles a storage codec for the provided storage media type, the provided serializer, and the requested
// storage and memory versions.
func NewStorageCodec(storageMediaType string, ns runtime.StorageSerializer, storageVersion, memoryVersion unversioned.GroupVersion, config storagebackend.Config) (runtime.Codec, error) {
	mediaType, _, err := mime.ParseMediaType(storageMediaType)
	if err != nil {
		return nil, fmt.Errorf("%q is not a valid mime-type", storageMediaType)
	}
	serializer, ok := runtime.SerializerInfoForMediaType(ns.SupportedMediaTypes(), mediaType)
	if !ok {
		return nil, fmt.Errorf("unable to find serializer for %q", storageMediaType)
	}

	s := serializer.Serializer

	// etcd2 only supports string data - we must wrap any result before returning
	// TODO: storagebackend should return a boolean indicating whether it supports binary data
	if !serializer.EncodesAsText && (config.Type == storagebackend.StorageTypeUnset || config.Type == storagebackend.StorageTypeETCD2) {
		glog.V(4).Infof("Wrapping the underlying binary storage serializer with a base64 encoding for etcd2")
		s = runtime.NewBase64Serializer(s)
	}

	encoder := ns.EncoderForVersion(
		s,
		runtime.NewMultiGroupVersioner(
			storageVersion,
			unversioned.GroupKind{Group: storageVersion.Group},
			unversioned.GroupKind{Group: memoryVersion.Group},
		),
	)

	ds := recognizer.NewDecoder(s, ns.UniversalDeserializer())
	decoder := ns.DecoderToVersion(
		ds,
		runtime.NewMultiGroupVersioner(
			memoryVersion,
			unversioned.GroupKind{Group: memoryVersion.Group},
			unversioned.GroupKind{Group: storageVersion.Group},
		),
	)

	return runtime.NewCodec(encoder, decoder), nil
}