cmd/protoc-gen-go-grpc: revert to interface-based service registration

balancer/grpclb/grpclb_test.go

@@ -276,6 +276,8 @@ func (b *remoteBalancer) BalanceLoad(stream lbgrpc.LoadBalancer_BalanceLoadServe
 }
 
 type testServer struct {
+	testpb.UnimplementedTestServiceServer
+
 	addr     string
 	fallback bool
 }
@@ -304,11 +306,7 @@ func startBackends(sn string, fallback bool, lis ...net.Listener) (servers []*gr
 			sn: sn,
 		}
 		s := grpc.NewServer(grpc.Creds(creds))
-		ts := &testServer{addr: l.Addr().String(), fallback: fallback}
-		testpb.RegisterTestServiceService(s, &testpb.TestServiceService{
-			EmptyCall:      ts.EmptyCall,
-			FullDuplexCall: ts.FullDuplexCall,
-		})
+		testpb.RegisterTestServiceServer(s, &testServer{addr: l.Addr().String(), fallback: fallback})
 		servers = append(servers, s)
 		go func(s *grpc.Server, l net.Listener) {
 			s.Serve(l)

balancer/roundrobin/roundrobin_test.go

@@ -47,11 +47,15 @@ func Test(t *testing.T) {
 	grpctest.RunSubTests(t, s{})
 }
 
-func emptyCall(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
+type testServer struct {
+	testpb.UnimplementedTestServiceServer
+}
+
+func (s *testServer) EmptyCall(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
 	return &testpb.Empty{}, nil
 }
 
-func fullDuplexCall(stream testpb.TestService_FullDuplexCallServer) error {
+func (s *testServer) FullDuplexCall(stream testpb.TestService_FullDuplexCallServer) error {
 	return nil
 }
 
@@ -81,10 +85,7 @@ func startTestServers(count int) (_ *test, err error) {
 		}
 
 		s := grpc.NewServer()
-		testpb.RegisterTestServiceService(s, &testpb.TestServiceService{
-			EmptyCall:      emptyCall,
-			FullDuplexCall: fullDuplexCall,
-		})
+		testpb.RegisterTestServiceServer(s, &testServer{})
 		t.servers = append(t.servers, s)
 		t.addresses = append(t.addresses, lis.Addr().String())
 

benchmark/benchmark.go

@@ -61,14 +61,8 @@ func NewPayload(t testpb.PayloadType, size int) *testpb.Payload {
 	return p
 }
 
-type testServer struct{}
-
-func (s *testServer) Svc() *testpb.BenchmarkServiceService {
-	return &testpb.BenchmarkServiceService{
-		UnaryCall:                  s.UnaryCall,
-		StreamingCall:              s.StreamingCall,
-		UnconstrainedStreamingCall: s.UnconstrainedStreamingCall,
-	}
+type testServer struct {
+	testpb.UnimplementedBenchmarkServiceServer
 }
 
 func (s *testServer) UnaryCall(ctx context.Context, in *testpb.SimpleRequest) (*testpb.SimpleResponse, error) {
@@ -150,17 +144,10 @@ func (s *testServer) UnconstrainedStreamingCall(stream testpb.BenchmarkService_U
 // byteBufServer is a gRPC server that sends and receives byte buffer.
 // The purpose is to benchmark the gRPC performance without protobuf serialization/deserialization overhead.
 type byteBufServer struct {
+	testpb.UnimplementedBenchmarkServiceServer
 	respSize int32
 }
 
-func (s *byteBufServer) Svc() *testpb.BenchmarkServiceService {
-	return &testpb.BenchmarkServiceService{
-		UnaryCall:                  s.UnaryCall,
-		StreamingCall:              s.StreamingCall,
-		UnconstrainedStreamingCall: s.UnconstrainedStreamingCall,
-	}
-}
-
 // UnaryCall is an empty function and is not used for benchmark.
 // If bytebuf UnaryCall benchmark is needed later, the function body needs to be updated.
 func (s *byteBufServer) UnaryCall(ctx context.Context, in *testpb.SimpleRequest) (*testpb.SimpleResponse, error) {
@@ -224,13 +211,13 @@ func StartServer(info ServerInfo, opts ...grpc.ServerOption) func() {
 	s := grpc.NewServer(opts...)
 	switch info.Type {
 	case "protobuf":
-		testpb.RegisterBenchmarkServiceService(s, (&testServer{}).Svc())
+		testpb.RegisterBenchmarkServiceServer(s, &testServer{})
 	case "bytebuf":
 		respSize, ok := info.Metadata.(int32)
 		if !ok {
 			logger.Fatalf("failed to StartServer, invalid metadata: %v, for Type: %v", info.Metadata, info.Type)
 		}
-		testpb.RegisterBenchmarkServiceService(s, (&byteBufServer{respSize: respSize}).Svc())
+		testpb.RegisterBenchmarkServiceServer(s, &byteBufServer{respSize: respSize})
 	default:
 		logger.Fatalf("failed to StartServer, unknown Type: %v", info.Type)
 	}