api: change ModPath() return value to Error from stream Error

cut useless grpc communication and improve performance

simple performance test result.
rib.20150617.2000 is taken from http://archive.routeviews.org/

[before]
$ time gomrt -i rib.20150617.2000
gomrt -i /vagrant/rib.20150617.2000  45.96s user 171.73s system 86% cpu
4:11.87 total

[after]
$ time gomrt -i rib.20150617.2000
gomrt -i /vagrant/rib.20150617.2000  11.95s user 76.17s system 74% cpu
1:58.38 total

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>

5 files changed, 26 insertions, 25 deletions

diff --git a/api/gobgp.pb.go b/api/gobgp.pb.go
index 060aaa68..7d01de14 100644
--- a/api/gobgp.pb.go
+++ b/api/gobgp.pb.go
@@ -1384,7 +1384,7 @@ func (c *grpcClient) ModPath(ctx context.Context, opts ...grpc.CallOption) (Grpc
 
 type Grpc_ModPathClient interface {
 	Send(*ModPathArguments) error
-	Recv() (*Error, error)
+	CloseAndRecv() (*Error, error)
 	grpc.ClientStream
 }
 
@@ -1396,7 +1396,10 @@ func (x *grpcModPathClient) Send(m *ModPathArguments) error {
 	return x.ClientStream.SendMsg(m)
 }
 
-func (x *grpcModPathClient) Recv() (*Error, error) {
+func (x *grpcModPathClient) CloseAndRecv() (*Error, error) {
+	if err := x.ClientStream.CloseSend(); err != nil {
+		return nil, err
+	}
 	m := new(Error)
 	if err := x.ClientStream.RecvMsg(m); err != nil {
 		return nil, err
@@ -1706,7 +1709,7 @@ func _Grpc_ModPath_Handler(srv interface{}, stream grpc.ServerStream) error {
 }
 
 type Grpc_ModPathServer interface {
-	Send(*Error) error
+	SendAndClose(*Error) error
 	Recv() (*ModPathArguments, error)
 	grpc.ServerStream
 }
@@ -1715,7 +1718,7 @@ type grpcModPathServer struct {
 	grpc.ServerStream
 }
 
-func (x *grpcModPathServer) Send(m *Error) error {
+func (x *grpcModPathServer) SendAndClose(m *Error) error {
 	return x.ServerStream.SendMsg(m)
 }
 
@@ -1888,7 +1891,6 @@ var _Grpc_serviceDesc = grpc.ServiceDesc{
 		{
 			StreamName:    "ModPath",
 			Handler:       _Grpc_ModPath_Handler,
-			ServerStreams: true,
 			ClientStreams: true,
 		},
 		{
diff --git a/api/gobgp.proto b/api/gobgp.proto
index b4beb1c2..e54eacca 100644
--- a/api/gobgp.proto
+++ b/api/gobgp.proto
@@ -31,7 +31,7 @@ service Grpc {
   rpc Shutdown(Arguments) returns (Error) {}
   rpc Enable(Arguments) returns (Error) {}
   rpc Disable(Arguments) returns (Error) {}
-  rpc ModPath(stream ModPathArguments) returns (stream Error) {}
+  rpc ModPath(stream ModPathArguments) returns (Error) {}
   rpc GetNeighborPolicy(Arguments) returns (ApplyPolicy) {}
   rpc ModNeighborPolicy(stream PolicyArguments) returns (stream Error) {}
   rpc GetPolicyRoutePolicies(PolicyArguments) returns (stream PolicyDefinition) {}
diff --git a/gobgp/global.go b/gobgp/global.go
index 7883c34a..b5f19ad3 100644
--- a/gobgp/global.go
+++ b/gobgp/global.go
@@ -190,7 +190,7 @@ func modPath(modtype string, eArgs []string) error {
 	}
 	stream.CloseSend()
 
-	res, e := stream.Recv()
+	res, e := stream.CloseAndRecv()
 	if e != nil {
 		return e
 	}
diff --git a/gomrt/main.go b/gomrt/main.go
index e587df78..1e44737f 100644
--- a/gomrt/main.go
+++ b/gomrt/main.go
@@ -141,15 +141,6 @@ func main() {
 						os.Exit(1)
 					}
 
-					res, err := stream.Recv()
-					if err != nil {
-						fmt.Println("failed to send:", err)
-						os.Exit(1)
-					}
-					if res.Code != api.Error_SUCCESS {
-						fmt.Errorf("error: code: %d, msg: %s", res.Code, res.Msg)
-						os.Exit(1)
-					}
 				}
 
 				idx += 1
@@ -158,6 +149,17 @@ func main() {
 					break
 				}
 			}
+
+			res, err := stream.CloseAndRecv()
+			if err != nil {
+				fmt.Println("failed to send:", err)
+				os.Exit(1)
+			}
+			if res.Code != api.Error_SUCCESS {
+				fmt.Errorf("error: code: %d, msg: %s", res.Code, res.Msg)
+				os.Exit(1)
+			}
+
 		},
 	}
 
diff --git a/server/grpc_server.go b/server/grpc_server.go
index ef850dbf..b14845b2 100644
--- a/server/grpc_server.go
+++ b/server/grpc_server.go
@@ -256,7 +256,7 @@ func (s *Server) ModPath(stream api.Grpc_ModPathServer) error {
 		arg, err := stream.Recv()
 
 		if err == io.EOF {
-			return nil
+			break
 		} else if err != nil {
 			return err
 		}
@@ -282,15 +282,12 @@ func (s *Server) ModPath(stream api.Grpc_ModPathServer) error {
 			log.Debug(err.Error())
 			return err
 		}
-
-		err = stream.Send(&api.Error{
-			Code: api.Error_SUCCESS,
-		})
-
-		if err != nil {
-			return err
-		}
 	}
+	err := stream.SendAndClose(&api.Error{
+		Code: api.Error_SUCCESS,
+	})
+
+	return err
 }
 
 func (s *Server) GetNeighborPolicy(ctx context.Context, arg *api.Arguments) (*api.ApplyPolicy, error) {