Refactoring

1. Renamed GetResponse to Query in DGraph service.
2. Client now accepts the ip of the server as a flag instead of just the port.
3. Removed ToProtocolBuffer method, and added PreTraverse as a method for a Subgraph.
4. Renamed runServerForClient to runGrpcServer.

client/go/main.go

@@ -28,13 +28,13 @@ import (
 )
 
 var glog = x.Log("client")
-var port = flag.String("port", "9090", "Port to communicate with server")
+var ip = flag.String("ip", "127.0.0.1:9090", "Port to communicate with server")
 var query = flag.String("query", "", "Query sent to the server")
 
 func main() {
 	flag.Parse()
 	// TODO(pawan): Pick address for server from config
-	conn, err := grpc.Dial("127.0.0.1:"+*port, grpc.WithInsecure())
+	conn, err := grpc.Dial(*ip, grpc.WithInsecure())
 	if err != nil {
 		x.Err(glog, err).Fatal("DialTCPConnection")
 	}
@@ -42,7 +42,7 @@ func main() {
 
 	c := pb.NewDGraphClient(conn)
 
-	r, err := c.GetResponse(context.Background(), &pb.GraphRequest{Query: *query})
+	r, err := c.Query(context.Background(), &pb.GraphRequest{Query: *query})
 	if err != nil {
 		x.Err(glog, err).Fatal("Error in getting response from server")
 	}

query/pb/graphresponse.pb.go

@@ -112,7 +112,7 @@ const _ = grpc.SupportPackageIsVersion2
 // Client API for DGraph service
 
 type DGraphClient interface {
-	GetResponse(ctx context.Context, in *GraphRequest, opts ...grpc.CallOption) (*GraphResponse, error)
+	Query(ctx context.Context, in *GraphRequest, opts ...grpc.CallOption) (*GraphResponse, error)
 }
 
 type dGraphClient struct {
@@ -123,9 +123,9 @@ func NewDGraphClient(cc *grpc.ClientConn) DGraphClient {
 	return &dGraphClient{cc}
 }
 
-func (c *dGraphClient) GetResponse(ctx context.Context, in *GraphRequest, opts ...grpc.CallOption) (*GraphResponse, error) {
+func (c *dGraphClient) Query(ctx context.Context, in *GraphRequest, opts ...grpc.CallOption) (*GraphResponse, error) {
 	out := new(GraphResponse)
-	err := grpc.Invoke(ctx, "/pb.DGraph/GetResponse", in, out, c.cc, opts...)
+	err := grpc.Invoke(ctx, "/pb.DGraph/Query", in, out, c.cc, opts...)
 	if err != nil {
 		return nil, err
 	}
@@ -135,27 +135,27 @@ func (c *dGraphClient) GetResponse(ctx context.Context, in *GraphRequest, opts .
 // Server API for DGraph service
 
 type DGraphServer interface {
-	GetResponse(context.Context, *GraphRequest) (*GraphResponse, error)
+	Query(context.Context, *GraphRequest) (*GraphResponse, error)
 }
 
 func RegisterDGraphServer(s *grpc.Server, srv DGraphServer) {
 	s.RegisterService(&_DGraph_serviceDesc, srv)
 }
 
-func _DGraph_GetResponse_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+func _DGraph_Query_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
 	in := new(GraphRequest)
 	if err := dec(in); err != nil {
 		return nil, err
 	}
 	if interceptor == nil {
-		return srv.(DGraphServer).GetResponse(ctx, in)
+		return srv.(DGraphServer).Query(ctx, in)
 	}
 	info := &grpc.UnaryServerInfo{
 		Server:     srv,
-		FullMethod: "/pb.DGraph/GetResponse",
+		FullMethod: "/pb.DGraph/Query",
 	}
 	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
-		return srv.(DGraphServer).GetResponse(ctx, req.(*GraphRequest))
+		return srv.(DGraphServer).Query(ctx, req.(*GraphRequest))
 	}
 	return interceptor(ctx, in, info, handler)
 }
@@ -165,29 +165,29 @@ var _DGraph_serviceDesc = grpc.ServiceDesc{
 	HandlerType: (*DGraphServer)(nil),
 	Methods: []grpc.MethodDesc{
 		{
-			MethodName: "GetResponse",
-			Handler:    _DGraph_GetResponse_Handler,
+			MethodName: "Query",
+			Handler:    _DGraph_Query_Handler,
 		},
 	},
 	Streams: []grpc.StreamDesc{},
 }
 
 var fileDescriptor0 = []byte{
-	// 256 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0x64, 0x90, 0x41, 0x4b, 0xc4, 0x30,
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-	0xec, 0x61, 0xf5, 0xec, 0x49, 0xd8, 0x83, 0x9e, 0x02, 0xfe, 0x80, 0xd6, 0x06, 0x37, 0x50, 0xb7,
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-	0x6b, 0xe0, 0xf8, 0xd5, 0x95, 0x76, 0xed, 0xb4, 0xb7, 0xed, 0xc6, 0xeb, 0xc2, 0xba, 0x96, 0x5a,
-	0x9c, 0xd8, 0x4a, 0x5e, 0xc0, 0xde, 0xb3, 0xa9, 0x9f, 0x8c, 0x27, 0x44, 0x98, 0x75, 0xa6, 0xf6,
-	0x79, 0x72, 0x39, 0x5d, 0xcc, 0x54, 0x98, 0xe5, 0x23, 0x08, 0xa5, 0x7d, 0xd7, 0x10, 0x9e, 0x82,
-	0xf8, 0x28, 0x9b, 0x4e, 0x0f, 0xfa, 0x5c, 0xc5, 0x0d, 0xaf, 0x21, 0x65, 0xe7, 0x5b, 0x49, 0xce,
-	0x7c, 0xe6, 0x13, 0x96, 0xb2, 0x65, 0x56, 0xd8, 0xaa, 0x88, 0xa9, 0x6a, 0x54, 0xe5, 0x15, 0xcc,
-	0x57, 0x3d, 0x86, 0xd2, 0xef, 0x7c, 0x49, 0x78, 0x02, 0xbb, 0x3c, 0xb8, 0x2f, 0x4e, 0x4c, 0x16,
-	0xa9, 0x1a, 0x16, 0xf9, 0x9d, 0xc0, 0x41, 0xb4, 0x0d, 0xb4, 0x78, 0x0e, 0x69, 0x49, 0x9c, 0x50,
-	0x75, 0xa4, 0xa3, 0x77, 0xfc, 0x80, 0x12, 0x84, 0x0b, 0x88, 0xdc, 0x9e, 0x70, 0x3b, 0xf4, 0xed,
-	0x03, 0xb4, 0x8a, 0x0a, 0xde, 0xc0, 0xfe, 0xcb, 0xda, 0x34, 0xb5, 0xd3, 0x9b, 0x7c, 0x1a, 0x18,
-	0x8f, 0x7a, 0xd7, 0x9f, 0x1a, 0xb5, 0xb5, 0x2c, 0xef, 0x41, 0x3c, 0x04, 0x0d, 0xef, 0x20, 0x5b,
-	0x69, 0xda, 0x92, 0x1c, 0xfe, 0xba, 0x0a, 0xff, 0x70, 0xf6, 0x3f, 0x47, 0xee, 0x54, 0x22, 0xbc,
-	0xef, 0xed, 0x4f, 0x00, 0x00, 0x00, 0xff, 0xff, 0xb2, 0xab, 0xec, 0x88, 0x76, 0x01, 0x00, 0x00,
+	// 255 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0x64, 0x90, 0x4f, 0x4b, 0xc4, 0x30,
+	0x10, 0xc5, 0xed, 0xfe, 0x89, 0x76, 0x76, 0x05, 0x1d, 0x45, 0x8a, 0x28, 0x48, 0xf0, 0xb0, 0x1e,
+	0xec, 0x61, 0xbd, 0xf8, 0x01, 0x04, 0x0f, 0x7a, 0x71, 0xc0, 0x0f, 0xd0, 0xda, 0xe0, 0x06, 0xea,
+	0x36, 0x26, 0xa9, 0xe8, 0xcd, 0x8f, 0xee, 0x34, 0x09, 0xae, 0xb2, 0xb7, 0x99, 0xbc, 0x97, 0xf7,
+	0x7e, 0x0c, 0x1c, 0xbd, 0xda, 0xca, 0xac, 0xac, 0x72, 0xa6, 0x5b, 0x3b, 0x55, 0x1a, 0xdb, 0xf9,
+	0x0e, 0x47, 0xa6, 0x96, 0xe7, 0xb0, 0xfb, 0xac, 0x9b, 0x47, 0xed, 0x3c, 0x22, 0x4c, 0x7a, 0xdd,
+	0xb8, 0x22, 0xbb, 0x18, 0x2f, 0x26, 0x14, 0x66, 0xf9, 0x00, 0x82, 0x94, 0xeb, 0x5b, 0x8f, 0x27,
+	0x20, 0x3e, 0xaa, 0xb6, 0x57, 0x51, 0x9f, 0x53, 0xda, 0xf0, 0x0a, 0x72, 0x76, 0xbe, 0x55, 0xde,
+	0xea, 0xcf, 0x62, 0xc4, 0xd2, 0x6c, 0x39, 0x2b, 0x4d, 0x5d, 0xa6, 0x54, 0xda, 0xa8, 0xf2, 0x12,
+	0xe6, 0xf7, 0x03, 0x06, 0xa9, 0x77, 0xfe, 0xe9, 0xf1, 0x18, 0xa6, 0x3c, 0xd8, 0x2f, 0x4e, 0xcc,
+	0x16, 0x39, 0xc5, 0x45, 0x7e, 0x67, 0xb0, 0x9f, 0x6c, 0x91, 0x16, 0xcf, 0x20, 0xaf, 0x3c, 0x27,
+	0xd4, 0xbd, 0x57, 0xc9, 0xbb, 0x79, 0x40, 0x09, 0xc2, 0x06, 0x44, 0x6e, 0xcf, 0xb8, 0x1d, 0x86,
+	0xf6, 0x08, 0x4d, 0x49, 0xc1, 0x6b, 0xd8, 0x7b, 0x59, 0xe9, 0xb6, 0xb1, 0x6a, 0x5d, 0x8c, 0x03,
+	0xe3, 0xe1, 0xe0, 0xfa, 0x57, 0x43, 0xbf, 0x96, 0xe5, 0x2d, 0x88, 0xbb, 0xa0, 0x61, 0x09, 0xd3,
+	0xa7, 0x81, 0x0a, 0x0f, 0xfe, 0xf8, 0x03, 0xfd, 0xe9, 0x76, 0x82, 0xdc, 0xa9, 0x45, 0xb8, 0xec,
+	0xcd, 0x4f, 0x00, 0x00, 0x00, 0xff, 0xff, 0xd9, 0x42, 0x7b, 0x6e, 0x70, 0x01, 0x00, 0x00,
 }

query/pb/graphresponse.proto

@@ -2,7 +2,7 @@ syntax="proto3";
 package pb;
 
 service DGraph {
-  rpc GetResponse (GraphRequest) returns (GraphResponse) {}
+  rpc Query (GraphRequest) returns (GraphResponse) {}
 }
 
 message UidList {

query/query.go

@@ -252,22 +252,14 @@ func (g *SubGraph) ToJson(l *Latency) (js []byte, rerr error) {
 	return json.Marshal(r)
 }
 
-func preTraverse(g *SubGraph) (gr *pb.GraphResponse, rerr error) {
-	gr = &pb.GraphResponse{}
-	if len(g.query) == 0 {
-		return gr, nil
-	}
-
-	gr.Attribute = g.Attr
-	ro := flatbuffers.GetUOffsetT(g.result)
-	r := new(task.Result)
-	r.Init(g.result, ro)
-
+// This method take in a flatbuffer result, extracts values and uids from it
+// and converts it to a protocol buffer result
+func extract(r *task.Result) (*pb.Result, error) {
+	var result = &pb.Result{}
 	var ul task.UidList
-	result := &pb.Result{}
 	for i := 0; i < r.UidmatrixLength(); i++ {
 		if ok := r.Uidmatrix(&ul, i); !ok {
-			return gr, fmt.Errorf("While parsing UidList")
+			return result, fmt.Errorf("While parsing UidList")
 		}
 
 		uidList := &pb.UidList{}
@@ -281,12 +273,12 @@ func preTraverse(g *SubGraph) (gr *pb.GraphResponse, rerr error) {
 	var tv task.Value
 	for i := 0; i < r.ValuesLength(); i++ {
 		if ok := r.Values(&tv, i); !ok {
-			return gr, fmt.Errorf("While parsing value")
+			return result, fmt.Errorf("While parsing value")
 		}
 
 		var ival interface{}
 		if err := posting.ParseValue(&ival, tv.ValBytes()); err != nil {
-			return gr, err
+			return result, err
 		}
 
 		if ival == nil {
@@ -294,11 +286,29 @@ func preTraverse(g *SubGraph) (gr *pb.GraphResponse, rerr error) {
 		}
 		result.Values = append(result.Values, []byte(ival.(string)))
 	}
+	return result, nil
+}
+
+func (g *SubGraph) PreTraverse() (gr *pb.GraphResponse, rerr error) {
+	gr = &pb.GraphResponse{}
+	if len(g.query) == 0 {
+		return gr, nil
+	}
+
+	gr.Attribute = g.Attr
+	ro := flatbuffers.GetUOffsetT(g.result)
+	r := new(task.Result)
+	r.Init(g.result, ro)
+
+	result, err := extract(r)
+	if err != nil {
+		return gr, err
+	}
 
 	gr.Result = result
 
 	for _, child := range g.Children {
-		childPb, err := preTraverse(child)
+		childPb, err := child.PreTraverse()
 		if err != nil {
 			x.Err(glog, err).Error("Error while traversal")
 			return gr, err
@@ -309,16 +319,6 @@ func preTraverse(g *SubGraph) (gr *pb.GraphResponse, rerr error) {
 	return gr, nil
 }
 
-func (g *SubGraph) ToProtocolBuffer() (gr *pb.GraphResponse, rerr error) {
-	gr, err := preTraverse(g)
-	if err != nil {
-		x.Err(glog, err).Error("Error while traversal")
-		return gr, err
-	}
-
-	return gr, nil
-}
-
 func treeCopy(gq *gql.GraphQuery, sg *SubGraph) {
 	for _, gchild := range gq.Children {
 		dst := new(SubGraph)

query/query_test.go

@@ -320,7 +320,7 @@ func TestToJson(t *testing.T) {
 	fmt.Printf(string(js))
 }
 
-func TestToProtocolBuffer(t *testing.T) {
+func TestPreTraverse(t *testing.T) {
 	dir, _ := populateGraph(t)
 	defer os.RemoveAll(dir)
 
@@ -353,7 +353,7 @@ func TestToProtocolBuffer(t *testing.T) {
 		t.Error(err)
 	}
 
-	ugr, err := sg.ToProtocolBuffer()
+	ugr, err := sg.PreTraverse()
 	if err != nil {
 		t.Error(err)
 	}

server/main.go

@@ -205,17 +205,16 @@ func queryHandler(w http.ResponseWriter, r *http.Request) {
 // server is used to implement pb.DGraphServer
 type server struct{}
 
-func (s *server) GetResponse(ctx context.Context, r *pb.GraphRequest) (gr *pb.GraphResponse, rerr error) {
-	q := []byte(r.Query)
-	if len(q) == 0 {
+func (s *server) Query(ctx context.Context, r *pb.GraphRequest) (gr *pb.GraphResponse, rerr error) {
+	if len(r.Query) == 0 {
 		glog.Error("While reading query")
 		return gr, fmt.Errorf("Empty query")
 	}
 
 	// TODO(pawan): Refactor query parsing and graph processing code to a common
-	// function used by pbQueryHandler and queryHandler
-	glog.WithField("q", string(q)).Debug("Query received.")
-	gq, _, err := gql.Parse(string(q))
+	// function used by Query and queryHandler
+	glog.WithField("q", r.Query).Debug("Query received.")
+	gq, _, err := gql.Parse(r.Query)
 	if err != nil {
 		x.Err(glog, err).Error("While parsing query")
 		return gr, err
@@ -226,7 +225,7 @@ func (s *server) GetResponse(ctx context.Context, r *pb.GraphRequest) (gr *pb.Gr
 		x.Err(glog, err).Error("While conversion to internal format")
 		return gr, err
 	}
-	glog.WithField("q", string(q)).Debug("Query parsed.")
+	glog.WithField("q", r.Query).Debug("Query parsed.")
 
 	rch := make(chan error)
 	go query.ProcessGraph(sg, rch)
@@ -236,17 +235,17 @@ func (s *server) GetResponse(ctx context.Context, r *pb.GraphRequest) (gr *pb.Gr
 		return gr, err
 	}
 
-	glog.WithField("q", string(q)).Debug("Graph processed.")
-	gr, err = sg.ToProtocolBuffer()
+	glog.WithField("q", r.Query).Debug("Graph processed.")
+	gr, err = sg.PreTraverse()
 	if err != nil {
-		x.Err(glog, err).Error("While converting to Json.")
+		x.Err(glog, err).Error("While converting to protocol buffer.")
 		return gr, err
 	}
 
 	return gr, err
 }
 
-func runServerForClient(address string) error {
+func runGrpcServer(address string) error {
 	ln, err := net.Listen("tcp", address)
 	if err != nil {
 		glog.Fatalf("While running server for client: %v", err)
@@ -306,7 +305,7 @@ func main() {
 
 	worker.Connect(addrs)
 
-	runServerForClient(":" + *clientPort)
+	runGrpcServer(":" + *clientPort)
 
 	http.HandleFunc("/query", queryHandler)
 	glog.WithField("port", *port).Info("Listening for requests...")