v3 refactor (#1868)

* Move to v3

Co-authored-by: Ben Toogood <bentoogood@gmail.com>

client/mucp/mucp_stream.go

@@ -0,0 +1,165 @@
+package mucp
+
+import (
+	"context"
+	"io"
+	"sync"
+
+	"github.com/micro/go-micro/v3/client"
+	"github.com/micro/go-micro/v3/codec"
+)
+
+// Implements the streamer interface
+type rpcStream struct {
+	sync.RWMutex
+	id       string
+	closed   chan bool
+	err      error
+	request  client.Request
+	response client.Response
+	codec    codec.Codec
+	context  context.Context
+
+	// signal whether we should send EOS
+	sendEOS bool
+
+	// release releases the connection back to the pool
+	release func(err error)
+}
+
+func (r *rpcStream) isClosed() bool {
+	select {
+	case <-r.closed:
+		return true
+	default:
+		return false
+	}
+}
+
+func (r *rpcStream) Context() context.Context {
+	return r.context
+}
+
+func (r *rpcStream) Request() client.Request {
+	return r.request
+}
+
+func (r *rpcStream) Response() client.Response {
+	return r.response
+}
+
+func (r *rpcStream) Send(msg interface{}) error {
+	r.Lock()
+	defer r.Unlock()
+
+	if r.isClosed() {
+		r.err = errShutdown
+		return errShutdown
+	}
+
+	req := codec.Message{
+		Id:       r.id,
+		Target:   r.request.Service(),
+		Method:   r.request.Method(),
+		Endpoint: r.request.Endpoint(),
+		Type:     codec.Request,
+	}
+
+	if err := r.codec.Write(&req, msg); err != nil {
+		r.err = err
+		return err
+	}
+
+	return nil
+}
+
+func (r *rpcStream) Recv(msg interface{}) error {
+	r.Lock()
+	defer r.Unlock()
+
+	if r.isClosed() {
+		r.err = errShutdown
+		return errShutdown
+	}
+
+	var resp codec.Message
+
+	r.Unlock()
+	err := r.codec.ReadHeader(&resp, codec.Response)
+	r.Lock()
+	if err != nil {
+		if err == io.EOF && !r.isClosed() {
+			r.err = io.ErrUnexpectedEOF
+			return io.ErrUnexpectedEOF
+		}
+		r.err = err
+		return err
+	}
+
+	switch {
+	case len(resp.Error) > 0:
+		// We've got an error response. Give this to the request;
+		// any subsequent requests will get the ReadResponseBody
+		// error if there is one.
+		if resp.Error != lastStreamResponseError {
+			r.err = serverError(resp.Error)
+		} else {
+			r.err = io.EOF
+		}
+		r.Unlock()
+		err = r.codec.ReadBody(nil)
+		r.Lock()
+		if err != nil {
+			r.err = err
+		}
+	default:
+		r.Unlock()
+		err = r.codec.ReadBody(msg)
+		r.Lock()
+		if err != nil {
+			r.err = err
+		}
+	}
+
+	return r.err
+}
+
+func (r *rpcStream) Error() error {
+	r.RLock()
+	defer r.RUnlock()
+	return r.err
+}
+
+func (r *rpcStream) Close() error {
+	r.Lock()
+
+	select {
+	case <-r.closed:
+		r.Unlock()
+		return nil
+	default:
+		close(r.closed)
+		r.Unlock()
+
+		// send the end of stream message
+		if r.sendEOS {
+			// no need to check for error
+			r.codec.Write(&codec.Message{
+				Id:       r.id,
+				Target:   r.request.Service(),
+				Method:   r.request.Method(),
+				Endpoint: r.request.Endpoint(),
+				Type:     codec.Error,
+				Error:    lastStreamResponseError,
+			}, nil)
+		}
+
+		err := r.codec.Close()
+
+		// release the connection
+		r.release(r.Error())
+
+		// return the codec error
+		return err
+	}
+}