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>

1 files changed, 11 insertions, 9 deletions

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)
+			}
+
 		},
 	}