Golang runtime.Unknown類代碼示例

// estimateUnknownSize returns the expected bytes consumed by a given runtime.Unknown
// object with a nil RawJSON struct and the expected size of the provided buffer. The
// returned size will not be correct if RawJSOn is set on unk.
func estimateUnknownSize(unk *runtime.Unknown, byteSize uint64) uint64 {
	size := uint64(unk.Size())
	// protobuf uses 1 byte for the tag, a varint for the length of the array (at most 8 bytes - uint64 - here),
	// and the size of the array.
	size += 1 + 8 + byteSize
	return size
}

// HandleWS implements a websocket handler.
func (s *WatchServer) HandleWS(ws *websocket.Conn) {
	defer ws.Close()
	done := make(chan struct{})
	go wsstream.IgnoreReceives(ws, 0)

	var unknown runtime.Unknown
	internalEvent := &versioned.InternalEvent{}
	buf := &bytes.Buffer{}
	streamBuf := &bytes.Buffer{}
	ch := s.watching.ResultChan()
	for {
		select {
		case <-done:
			s.watching.Stop()
			return
		case event, ok := <-ch:
			if !ok {
				// End of results.
				return
			}
			obj := event.Object
			s.fixup(obj)
			if err := s.embeddedEncoder.Encode(obj, buf); err != nil {
				// unexpected error
				utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v", err))
				return
			}

			// ContentType is not required here because we are defaulting to the serializer
			// type
			unknown.Raw = buf.Bytes()
			event.Object = &unknown

			// the internal event will be versioned by the encoder
			*internalEvent = versioned.InternalEvent(event)
			if err := s.encoder.Encode(internalEvent, streamBuf); err != nil {
				// encoding error
				utilruntime.HandleError(fmt.Errorf("unable to encode event: %v", err))
				s.watching.Stop()
				return
			}
			if s.useTextFraming {
				if err := websocket.Message.Send(ws, streamBuf.String()); err != nil {
					// Client disconnect.
					s.watching.Stop()
					return
				}
			} else {
				if err := websocket.Message.Send(ws, streamBuf.Bytes()); err != nil {
					// Client disconnect.
					s.watching.Stop()
					return
				}
			}
			buf.Reset()
			streamBuf.Reset()
		}
	}
}

// EncodeToStream serializes the provided object to the given writer. Overrides is ignored.
func (s *Serializer) EncodeToStream(obj runtime.Object, w io.Writer, overrides ...unversioned.GroupVersion) error {
	var unk runtime.Unknown
	if kind := obj.GetObjectKind().GroupVersionKind(); kind != nil {
		unk = runtime.Unknown{
			TypeMeta: runtime.TypeMeta{
				Kind:       kind.Kind,
				APIVersion: kind.GroupVersion().String(),
			},
		}
	}

	prefixSize := uint64(len(s.prefix))

	switch t := obj.(type) {
	case bufferedMarshaller:
		// this path performs a single allocation during write but requires the caller to implement
		// the more efficient Size and MarshalTo methods
		encodedSize := uint64(t.Size())
		estimatedSize := prefixSize + estimateUnknownSize(&unk, encodedSize)
		data := make([]byte, estimatedSize)

		i, err := unk.NestedMarshalTo(data[prefixSize:], t, encodedSize)
		if err != nil {
			return err
		}

		copy(data, s.prefix)

		_, err = w.Write(data[:prefixSize+uint64(i)])
		return err

	case proto.Marshaler:
		// this path performs extra allocations
		data, err := t.Marshal()
		if err != nil {
			return err
		}
		unk.Raw = data

		estimatedSize := prefixSize + uint64(unk.Size())
		data = make([]byte, estimatedSize)

		i, err := unk.MarshalTo(data[prefixSize:])
		if err != nil {
			return err
		}

		copy(data, s.prefix)

		_, err = w.Write(data[:prefixSize+uint64(i)])
		return err

	default:
		// TODO: marshal with a different content type and serializer (JSON for third party objects)
		return errNotMarshalable{reflect.TypeOf(obj)}
	}
}

// Decode attempts to convert the provided data into a protobuf message, extract the stored schema kind, apply the provided default
// gvk, and then load that data into an object matching the desired schema kind or the provided into. If into is *runtime.Unknown,
// the raw data will be extracted and no decoding will be performed. If into is not registered with the typer, then the object will
// be straight decoded using normal protobuf unmarshalling (the MarshalTo interface). If into is provided and the original data is
// not fully qualified with kind/version/group, the type of the into will be used to alter the returned gvk. On success or most
// errors, the method will return the calculated schema kind.
func (s *Serializer) Decode(originalData []byte, gvk *unversioned.GroupVersionKind, into runtime.Object) (runtime.Object, *unversioned.GroupVersionKind, error) {
	if versioned, ok := into.(*runtime.VersionedObjects); ok {
		into = versioned.Last()
		obj, actual, err := s.Decode(originalData, gvk, into)
		if err != nil {
			return nil, actual, err
		}
		// the last item in versioned becomes into, so if versioned was not originally empty we reset the object
		// array so the first position is the decoded object and the second position is the outermost object.
		// if there were no objects in the versioned list passed to us, only add ourselves.
		if into != nil && into != obj {
			versioned.Objects = []runtime.Object{obj, into}
		} else {
			versioned.Objects = []runtime.Object{obj}
		}
		return versioned, actual, err
	}

	prefixLen := len(s.prefix)
	switch {
	case len(originalData) == 0:
		// TODO: treat like decoding {} from JSON with defaulting
		return nil, nil, fmt.Errorf("empty data")
	case len(originalData) < prefixLen || !bytes.Equal(s.prefix, originalData[:prefixLen]):
		return nil, nil, fmt.Errorf("provided data does not appear to be a protobuf message, expected prefix %v", s.prefix)
	case len(originalData) == prefixLen:
		// TODO: treat like decoding {} from JSON with defaulting
		return nil, nil, fmt.Errorf("empty body")
	}

	data := originalData[prefixLen:]
	unk := runtime.Unknown{}
	if err := unk.Unmarshal(data); err != nil {
		return nil, nil, err
	}

	actual := unk.GroupVersionKind()
	copyKindDefaults(actual, gvk)

	if intoUnknown, ok := into.(*runtime.Unknown); ok && intoUnknown != nil {
		*intoUnknown = unk
		if len(intoUnknown.ContentType) == 0 {
			intoUnknown.ContentType = s.contentType
		}
		return intoUnknown, actual, nil
	}

	if into != nil {
		typed, _, err := s.typer.ObjectKind(into)
		switch {
		case runtime.IsNotRegisteredError(err):
			pb, ok := into.(proto.Message)
			if !ok {
				return nil, actual, errNotMarshalable{reflect.TypeOf(into)}
			}
			if err := proto.Unmarshal(unk.Raw, pb); err != nil {
				return nil, actual, err
			}
			return into, actual, nil
		case err != nil:
			return nil, actual, err
		default:
			copyKindDefaults(actual, typed)
			// if the result of defaulting did not set a version or group, ensure that at least group is set
			// (copyKindDefaults will not assign Group if version is already set). This guarantees that the group
			// of into is set if there is no better information from the caller or object.
			if len(actual.Version) == 0 && len(actual.Group) == 0 {
				actual.Group = typed.Group
			}
		}
	}

	if len(actual.Kind) == 0 {
		return nil, actual, runtime.NewMissingKindErr(fmt.Sprintf("%#v", unk.TypeMeta))
	}
	if len(actual.Version) == 0 {
		return nil, actual, runtime.NewMissingVersionErr(fmt.Sprintf("%#v", unk.TypeMeta))
	}

	return unmarshalToObject(s.typer, s.creater, actual, into, unk.Raw)
}

// ServeHTTP serves a series of encoded events via HTTP with Transfer-Encoding: chunked
// or over a websocket connection.
func (s *WatchServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	w = httplog.Unlogged(w)

	if wsstream.IsWebSocketRequest(req) {
		w.Header().Set("Content-Type", s.mediaType)
		websocket.Handler(s.HandleWS).ServeHTTP(w, req)
		return
	}

	cn, ok := w.(http.CloseNotifier)
	if !ok {
		err := fmt.Errorf("unable to start watch - can't get http.CloseNotifier: %#v", w)
		utilruntime.HandleError(err)
		s.scope.err(errors.NewInternalError(err), w, req)
		return
	}
	flusher, ok := w.(http.Flusher)
	if !ok {
		err := fmt.Errorf("unable to start watch - can't get http.Flusher: %#v", w)
		utilruntime.HandleError(err)
		s.scope.err(errors.NewInternalError(err), w, req)
		return
	}

	framer := s.framer.NewFrameWriter(w)
	if framer == nil {
		// programmer error
		err := fmt.Errorf("no stream framing support is available for media type %q", s.mediaType)
		utilruntime.HandleError(err)
		s.scope.err(errors.NewBadRequest(err.Error()), w, req)
		return
	}
	e := streaming.NewEncoder(framer, s.encoder)

	// ensure the connection times out
	timeoutCh, cleanup := s.t.TimeoutCh()
	defer cleanup()
	defer s.watching.Stop()

	// begin the stream
	w.Header().Set("Content-Type", s.mediaType)
	w.Header().Set("Transfer-Encoding", "chunked")
	w.WriteHeader(http.StatusOK)
	flusher.Flush()

	var unknown runtime.Unknown
	internalEvent := &versioned.InternalEvent{}
	buf := &bytes.Buffer{}
	ch := s.watching.ResultChan()
	for {
		select {
		case <-cn.CloseNotify():
			return
		case <-timeoutCh:
			return
		case event, ok := <-ch:
			if !ok {
				// End of results.
				return
			}

			obj := event.Object
			s.fixup(obj)
			if err := s.embeddedEncoder.Encode(obj, buf); err != nil {
				// unexpected error
				utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v", err))
				return
			}

			// ContentType is not required here because we are defaulting to the serializer
			// type
			unknown.Raw = buf.Bytes()
			event.Object = &unknown

			// the internal event will be versioned by the encoder
			*internalEvent = versioned.InternalEvent(event)
			if err := e.Encode(internalEvent); err != nil {
				utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v (%#v)", err, e))
				// client disconnect.
				return
			}
			if len(ch) == 0 {
				flusher.Flush()
			}

			buf.Reset()
		}
	}
}