rpc: golint comments

rpc/client.go

@@ -36,6 +36,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 )
 
+// Vars hardcodes custom error messages.
 var (
 	ErrClientQuit                = errors.New("client is closed")
 	ErrNoResult                  = errors.New("no result in JSON-RPC response")
@@ -191,29 +192,37 @@ func (io StdIOConn) Write(b []byte) (n int, err error) {
 	return os.Stdout.Write(b)
 }
 
+// Close is a noop.
 func (io StdIOConn) Close() error {
 	return nil
 }
 
+// LocalAddr sets the address of a Unix domain socket end point.
 func (io StdIOConn) LocalAddr() net.Addr {
 	return &net.UnixAddr{Name: "stdio", Net: "stdio"}
 }
 
+// RemoteAddr sets the remote address of a Unix domain socket end point.
 func (io StdIOConn) RemoteAddr() net.Addr {
 	return &net.UnixAddr{Name: "stdio", Net: "stdio"}
 }
 
+// SetDeadline sets the operation, network type, and address of an error.
 func (io StdIOConn) SetDeadline(t time.Time) error {
 	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
 }
 
+// SetReadDeadline sets the operation, network type, and address of an error.
 func (io StdIOConn) SetReadDeadline(t time.Time) error {
 	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
 }
 
+// SetWriteDeadline sets the operation, network type, and address of an error.
 func (io StdIOConn) SetWriteDeadline(t time.Time) error {
 	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
 }
+
+// DialStdIO returns a new client instance with ctx values.
 func DialStdIO(ctx context.Context) (*Client, error) {
 	return newClient(ctx, func(_ context.Context) (net.Conn, error) {
 		return StdIOConn{}, nil
@@ -329,7 +338,7 @@ func (c *Client) BatchCall(b []BatchElem) error {
 	return c.BatchCallContext(ctx, b)
 }
 
-// BatchCall sends all given requests as a single batch and waits for the server
+// BatchCallContext sends all given requests as a single batch and waits for the server
 // to return a response for all of them. The wait duration is bounded by the
 // context's deadline.
 //
@@ -781,7 +790,7 @@ func (sub *ClientSubscription) start() {
 	sub.quitWithError(sub.forward())
 }
 
-func (sub *ClientSubscription) forward() (err error, unsubscribeServer bool) {
+func (sub *ClientSubscription) forward() (unsubscribeServer bool, err error) {
 	cases := []reflect.SelectCase{
 		{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(sub.quit)},
 		{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(sub.in)},
@@ -803,14 +812,14 @@ func (sub *ClientSubscription) forward() (err error, unsubscribeServer bool) {
 
 		switch chosen {
 		case 0: // <-sub.quit
-			return nil, false
+			return false, nil
 		case 1: // <-sub.in
 			val, err := sub.unmarshal(recv.Interface().(json.RawMessage))
 			if err != nil {
-				return err, true
+				return true, err
 			}
 			if buffer.Len() == maxClientSubscriptionBuffer {
-				return ErrSubscriptionQueueOverflow, true
+				return true, ErrSubscriptionQueueOverflow
 			}
 			buffer.PushBack(val)
 		case 2: // sub.channel<-

rpc/http.go

@@ -173,6 +173,11 @@ func NewHTTPServer(cors []string, vhosts []string, srv *Server) *http.Server {
 	}
 }
 
+type contextKey string
+func contextString(c contextKey) string {
+    return string(c)
+}
+
 // ServeHTTP serves JSON-RPC requests over HTTP.
 func (srv *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// Permit dumb empty requests for remote health-checks (AWS)
@@ -183,13 +188,16 @@ func (srv *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), code)
 		return
 	}
+
+	rem, sch, loc := contextKey("remote"), contextKey("scheme"), contextKey("local")
+
 	// All checks passed, create a codec that reads direct from the request body
 	// untilEOF and writes the response to w and order the server to process a
 	// single request.
 	ctx := r.Context()
-	ctx = context.WithValue(ctx, "remote", r.RemoteAddr)
+	ctx = context.WithValue(ctx, remote, r.RemoteAddr)
-	ctx = context.WithValue(ctx, "scheme", r.Proto)
+	ctx = context.WithValue(ctx, sch, r.Proto)
-	ctx = context.WithValue(ctx, "local", r.Host)
+	ctx = context.WithValue(ctx, loc, r.Host)
 
 	body := io.LimitReader(r.Body, maxRequestContentLength)
 	codec := NewJSONCodec(&httpReadWriteNopCloser{body, w})

rpc/json.go

@@ -40,13 +40,13 @@ const (
 type jsonRequest struct {
 	Method  string          `json:"method"`
 	Version string          `json:"jsonrpc"`
-	Id      json.RawMessage `json:"id,omitempty"`
+	ID      json.RawMessage `json:"id,omitempty"`
 	Payload json.RawMessage `json:"params,omitempty"`
 }
 
 type jsonSuccessResponse struct {
 	Version string      `json:"jsonrpc"`
-	Id      interface{} `json:"id,omitempty"`
+	ID      interface{} `json:"id,omitempty"`
 	Result  interface{} `json:"result"`
 }
 
@@ -58,7 +58,7 @@ type jsonError struct {
 
 type jsonErrResponse struct {
 	Version string      `json:"jsonrpc"`
-	Id      interface{} `json:"id,omitempty"`
+	ID      interface{} `json:"id,omitempty"`
 	Error   jsonError   `json:"error"`
 }
 
@@ -150,17 +150,17 @@ func (c *jsonCodec) ReadRequestHeaders() ([]rpcRequest, bool, Error) {
 	return parseRequest(incomingMsg)
 }
 
-// checkReqId returns an error when the given reqId isn't valid for RPC method calls.
+// checkReqID returns an error when the given reqID isn't valid for RPC method calls.
 // valid id's are strings, numbers or null
-func checkReqId(reqId json.RawMessage) error {
+func checkReqID(reqID json.RawMessage) error {
-	if len(reqId) == 0 {
+	if len(reqID) == 0 {
 		return fmt.Errorf("missing request id")
 	}
-	if _, err := strconv.ParseFloat(string(reqId), 64); err == nil {
+	if _, err := strconv.ParseFloat(string(reqID), 64); err == nil {
 		return nil
 	}
 	var str string
-	if err := json.Unmarshal(reqId, &str); err == nil {
+	if err := json.Unmarshal(reqID, &str); err == nil {
 		return nil
 	}
 	return fmt.Errorf("invalid request id")
@@ -175,13 +175,13 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error) {
 		return nil, false, &invalidMessageError{err.Error()}
 	}
 
-	if err := checkReqId(in.Id); err != nil {
+	if err := checkReqID(in.ID); err != nil {
 		return nil, false, &invalidMessageError{err.Error()}
 	}
 
 	// subscribe are special, they will always use `subscribeMethod` as first param in the payload
 	if strings.HasSuffix(in.Method, subscribeMethodSuffix) {
-		reqs := []rpcRequest{{id: &in.Id, isPubSub: true}}
+		reqs := []rpcRequest{{id: &in.ID, isPubSub: true}}
 		if len(in.Payload) > 0 {
 			// first param must be subscription name
 			var subscribeMethod [1]string
@@ -198,7 +198,7 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error) {
 	}
 
 	if strings.HasSuffix(in.Method, unsubscribeMethodSuffix) {
-		return []rpcRequest{{id: &in.Id, isPubSub: true,
+		return []rpcRequest{{id: &in.ID, isPubSub: true,
 			method: in.Method, params: in.Payload}}, false, nil
 	}
 
@@ -209,10 +209,10 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error) {
 
 	// regular RPC call
 	if len(in.Payload) == 0 {
-		return []rpcRequest{{service: elems[0], method: elems[1], id: &in.Id}}, false, nil
+		return []rpcRequest{{service: elems[0], method: elems[1], id: &in.ID}}, false, nil
 	}
 
-	return []rpcRequest{{service: elems[0], method: elems[1], id: &in.Id, params: in.Payload}}, false, nil
+	return []rpcRequest{{service: elems[0], method: elems[1], id: &in.ID, params: in.Payload}}, false, nil
 }
 
 // parseBatchRequest will parse a batch request into a collection of requests from the given RawMessage, an indication
@@ -225,11 +225,11 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error)
 
 	requests := make([]rpcRequest, len(in))
 	for i, r := range in {
-		if err := checkReqId(r.Id); err != nil {
+		if err := checkReqID(r.ID); err != nil {
 			return nil, false, &invalidMessageError{err.Error()}
 		}
 
-		id := &in[i].Id
+		id := &in[i].ID
 
 		// subscribe are special, they will always use `subscriptionMethod` as first param in the payload
 		if strings.HasSuffix(r.Method, subscribeMethodSuffix) {
@@ -275,9 +275,8 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error)
 func (c *jsonCodec) ParseRequestArguments(argTypes []reflect.Type, params interface{}) ([]reflect.Value, Error) {
 	if args, ok := params.(json.RawMessage); !ok {
 		return nil, &invalidParamsError{"Invalid params supplied"}
-	} else {
-		return parsePositionalArguments(args, argTypes)
 	}
+	return parsePositionalArguments(args, argTypes)
 }
 
 // parsePositionalArguments tries to parse the given args to an array of values with the
@@ -321,20 +320,20 @@ func parsePositionalArguments(rawArgs json.RawMessage, types []reflect.Type) ([]
 // CreateResponse will create a JSON-RPC success response with the given id and reply as result.
 func (c *jsonCodec) CreateResponse(id interface{}, reply interface{}) interface{} {
 	if isHexNum(reflect.TypeOf(reply)) {
-		return &jsonSuccessResponse{Version: jsonrpcVersion, Id: id, Result: fmt.Sprintf(`%#x`, reply)}
+		return &jsonSuccessResponse{Version: jsonrpcVersion, ID: id, Result: fmt.Sprintf(`%#x`, reply)}
 	}
-	return &jsonSuccessResponse{Version: jsonrpcVersion, Id: id, Result: reply}
+	return &jsonSuccessResponse{Version: jsonrpcVersion, ID: id, Result: reply}
 }
 
 // CreateErrorResponse will create a JSON-RPC error response with the given id and error.
 func (c *jsonCodec) CreateErrorResponse(id interface{}, err Error) interface{} {
-	return &jsonErrResponse{Version: jsonrpcVersion, Id: id, Error: jsonError{Code: err.ErrorCode(), Message: err.Error()}}
+	return &jsonErrResponse{Version: jsonrpcVersion, ID: id, Error: jsonError{Code: err.ErrorCode(), Message: err.Error()}}
 }
 
 // CreateErrorResponseWithInfo will create a JSON-RPC error response with the given id and error.
 // info is optional and contains additional information about the error. When an empty string is passed it is ignored.
 func (c *jsonCodec) CreateErrorResponseWithInfo(id interface{}, err Error, info interface{}) interface{} {
-	return &jsonErrResponse{Version: jsonrpcVersion, Id: id,
+	return &jsonErrResponse{Version: jsonrpcVersion, ID: id,
 		Error: jsonError{Code: err.ErrorCode(), Message: err.Error(), Data: info}}
 }
 

rpc/json_test.go

@@ -69,8 +69,8 @@ func TestJSONRequestParsing(t *testing.T) {
 		t.Fatalf("Expected method 'Add' but got '%s'", requests[0].method)
 	}
 
-	if rawId, ok := requests[0].id.(*json.RawMessage); ok {
+	if rawID, ok := requests[0].id.(*json.RawMessage); ok {
-		id, e := strconv.ParseInt(string(*rawId), 0, 64)
+		id, e := strconv.ParseInt(string(*rawID), 0, 64)
 		if e != nil {
 			t.Fatalf("%v", e)
 		}

rpc/server.go

@@ -29,7 +29,7 @@ import (
 	"gopkg.in/fatih/set.v0"
 )
 
-const MetadataApi = "rpc"
+const MetadataAPI = "rpc"
 
 // CodecOption specifies which type of messages this codec supports
 type CodecOption int
@@ -52,20 +52,20 @@ func NewServer() *Server {
 
 	// register a default service which will provide meta information about the RPC service such as the services and
 	// methods it offers.
-	rpcService := &RPCService{server}
+	rpcService := &Service{server}
-	server.RegisterName(MetadataApi, rpcService)
+	server.RegisterName(MetadataAPI, rpcService)
 
 	return server
 }
 
-// RPCService gives meta information about the server.
+// Service gives meta information about the server.
 // e.g. gives information about the loaded modules.
-type RPCService struct {
+type Service struct {
 	server *Server
 }
 
 // Modules returns the list of RPC services with their version number
-func (s *RPCService) Modules() map[string]string {
+func (s *Service) Modules() map[string]string {
 	modules := make(map[string]string)
 	for name := range s.server.services {
 		modules[name] = "1.0"

rpc/server_test.go

@@ -59,8 +59,8 @@ func (s *Service) Rets() (string, error) {
 	return "", nil
 }
 
-func (s *Service) InvalidRets1() (error, string) {
+func (s *Service) InvalidRets1() (string, error) {
-	return nil, ""
+	return "", nil
 }
 
 func (s *Service) InvalidRets2() (string, string) {

rpc/subscription.go

@@ -25,14 +25,14 @@ import (
 var (
 	// ErrNotificationsUnsupported is returned when the connection doesn't support notifications
 	ErrNotificationsUnsupported = errors.New("notifications not supported")
-	// ErrNotificationNotFound is returned when the notification for the given id is not found
+	// ErrSubscriptionNotFound is returned when the notification for the given id is not found
 	ErrSubscriptionNotFound = errors.New("subscription not found")
 )
 
 // ID defines a pseudo random number that is used to identify RPC subscriptions.
 type ID string
 
-// a Subscription is created by a notifier and tight to that notifier. The client can use
+// Subscription is created by a notifier and tight to that notifier. The client can use
 // this subscription to wait for an unsubscribe request for the client, see Err().
 type Subscription struct {
 	ID        ID

rpc/types.go

@@ -160,6 +160,7 @@ func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
+// Int64 casts the bn into int64.
 func (bn BlockNumber) Int64() int64 {
 	return (int64)(bn)
 }

rpc/utils.go

@@ -230,12 +230,12 @@ func NewID() ID {
 		}
 	}
 
-	rpcId := hex.EncodeToString(id)
+	rpcID := hex.EncodeToString(id)
 	// rpc ID's are RPC quantities, no leading zero's and 0 is 0x0
-	rpcId = strings.TrimLeft(rpcId, "0")
+	rpcID = strings.TrimLeft(rpcID, "0")
-	if rpcId == "" {
+	if rpcID == "" {
-		rpcId = "0"
+		rpcID = "0"
 	}
 
-	return ID("0x" + rpcId)
+	return ID("0x" + rpcID)
 }