grpc: avoid allocations for each message (#1939)

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

grpc.go

@@ -64,6 +64,8 @@ type grpcServer struct {
 
 	// registry service instance
 	rsvc *registry.Service
+
+	codecs map[string]encoding.Codec
 }
 
 func init() {
@@ -73,22 +75,19 @@ func init() {
 }
 
 func newGRPCServer(opts ...server.Option) server.Server {
-	options := newOptions(opts...)
-
 	// create a grpc server
 	srv := &grpcServer{
-		opts: options,
+		opts: server.Options{},
 		rpc: &rServer{
 			serviceMap: make(map[string]*service),
 		},
 		handlers:    make(map[string]server.Handler),
 		subscribers: make(map[*subscriber][]broker.Subscriber),
 		exit:        make(chan chan error),
-		wg:          wait(options.Context),
 	}
 
 	// configure the grpc server
-	srv.configure()
+	srv.configure(opts...)
 
 	return srv
 }
@@ -110,8 +109,8 @@ func (g *grpcServer) configure(opts ...server.Option) {
 	g.Lock()
 	defer g.Unlock()
 
-	// Don't reprocess where there's no config
-	if len(opts) == 0 && g.srv != nil {
+	// Don't reprocess if server created
+	if g.srv != nil {
 		return
 	}
 
@@ -121,6 +120,22 @@ func (g *grpcServer) configure(opts ...server.Option) {
 
 	g.wg = wait(g.opts.Context)
 
+	g.codecs = make(map[string]encoding.Codec, len(defaultGRPCCodecs))
+	for k, v := range defaultGRPCCodecs {
+		g.codecs[k] = v
+	}
+
+	var codecs map[string]encoding.Codec
+	if g.opts.Context != nil {
+		if v, ok := g.opts.Context.Value(codecsKey{}).(map[string]encoding.Codec); ok && v != nil {
+			codecs = v
+		}
+	}
+
+	for k, v := range codecs {
+		g.codecs[k] = v
+	}
+
 	maxMsgSize := g.getMaxMsgSize()
 
 	gopts := []grpc.ServerOption{
@@ -519,18 +534,13 @@ func (g *grpcServer) processStream(stream grpc.ServerStream, service *service, m
 }
 
 func (g *grpcServer) newGRPCCodec(contentType string) (encoding.Codec, error) {
-	codecs := make(map[string]encoding.Codec)
-	if g.opts.Context != nil {
-		if v, ok := g.opts.Context.Value(codecsKey{}).(map[string]encoding.Codec); ok && v != nil {
-			codecs = v
-		}
-	}
-	if c, ok := codecs[contentType]; ok {
-		return c, nil
-	}
-	if c, ok := defaultGRPCCodecs[contentType]; ok {
+	g.RLock()
+	defer g.RUnlock()
+
+	if c, ok := g.codecs[contentType]; ok {
 		return c, nil
 	}
+
 	return nil, fmt.Errorf("Unsupported Content-Type: %s", contentType)
 }