json.RawMessage in RPCRequest to defer parsing

rpc/lib/client/http_client.go

@@ -67,11 +67,9 @@ func NewJSONRPCClient(remote string) *JSONRPCClient {
 }
 
 func (c *JSONRPCClient) Call(method string, params map[string]interface{}, result interface{}) (interface{}, error) {
-	request := types.RPCRequest{
-		JSONRPC: "2.0",
-		Method:  method,
-		Params:  params,
-		ID:      "",
+	request, err := types.MapToRequest("", method, params)
+	if err != nil {
+		return nil, err
 	}
 	requestBytes, err := json.Marshal(request)
 	if err != nil {

rpc/lib/client/ws_client.go

@@ -130,35 +130,31 @@ func (wsc *WSClient) receiveEventsRoutine() {
 // Subscribe to an event. Note the server must have a "subscribe" route
 // defined.
 func (wsc *WSClient) Subscribe(eventid string) error {
-	err := wsc.WriteJSON(types.RPCRequest{
-		JSONRPC: "2.0",
-		ID:      "",
-		Method:  "subscribe",
-		Params:  map[string]interface{}{"event": eventid},
-	})
+	params := map[string]interface{}{"event": eventid}
+	request, err := types.MapToRequest("", "subscribe", params)
+	if err == nil {
+		err = wsc.WriteJSON(request)
+	}
 	return err
 }
 
 // Unsubscribe from an event. Note the server must have a "unsubscribe" route
 // defined.
 func (wsc *WSClient) Unsubscribe(eventid string) error {
-	err := wsc.WriteJSON(types.RPCRequest{
-		JSONRPC: "2.0",
-		ID:      "",
-		Method:  "unsubscribe",
-		Params:  map[string]interface{}{"event": eventid},
-	})
+	params := map[string]interface{}{"event": eventid}
+	request, err := types.MapToRequest("", "unsubscribe", params)
+	if err == nil {
+		err = wsc.WriteJSON(request)
+	}
 	return err
 }
 
 // Call asynchronously calls a given method by sending an RPCRequest to the
 // server. Results will be available on ResultsCh, errors, if any, on ErrorsCh.
 func (wsc *WSClient) Call(method string, params map[string]interface{}) error {
-	err := wsc.WriteJSON(types.RPCRequest{
-		JSONRPC: "2.0",
-		Method:  method,
-		Params:  params,
-		ID:      "",
-	})
+	request, err := types.MapToRequest("", method, params)
+	if err == nil {
+		err = wsc.WriteJSON(request)
+	}
 	return err
 }

rpc/lib/rpc_test.go

@@ -306,12 +306,9 @@ func TestWSHandlesArrayParams(t *testing.T) {
 
 	val := "acbd"
 	params := []interface{}{val}
-	err = cl.WriteJSON(types.RPCRequest{
-		JSONRPC: "2.0",
-		ID:      "",
-		Method:  "echo_ws",
-		Params:  params,
-	})
+	request, err := types.ArrayToRequest("", "echo_ws", params)
+	require.Nil(t, err)
+	err = cl.WriteJSON(request)
 	require.Nil(t, err)
 
 	select {

rpc/lib/server/handlers.go

@@ -140,15 +140,23 @@ func makeJSONRPCHandler(funcMap map[string]*RPCFunc) http.HandlerFunc {
 	}
 }
 
-// Convert a []interface{} OR a map[string]interface{} to properly typed values
+// raw is unparsed json (from json.RawMessage).  It either has
+// and array or a map behind it, let's parse this all without resorting to wire...
 //
 // argsOffset should be 0 for RPC calls, and 1 for WS requests, where len(rpcFunc.args) != len(rpcFunc.argNames).
 // Example:
 //   rpcFunc.args = [rpctypes.WSRPCContext string]
 //   rpcFunc.argNames = ["arg"]
-func jsonParamsToArgs(rpcFunc *RPCFunc, paramsI interface{}, argsOffset int) ([]reflect.Value, error) {
+func jsonParamsToArgs(rpcFunc *RPCFunc, raw []byte, argsOffset int) ([]reflect.Value, error) {
 	values := make([]reflect.Value, len(rpcFunc.argNames))
 
+	// right now, this is the same as before, but the whole parsing is in one function...
+	var paramsI interface{}
+	err := json.Unmarshal(raw, &paramsI)
+	if err != nil {
+		return nil, err
+	}
+
 	switch params := paramsI.(type) {
 
 	case map[string]interface{}:
@@ -188,13 +196,13 @@ func jsonParamsToArgs(rpcFunc *RPCFunc, paramsI interface{}, argsOffset int) ([]
 }
 
 // Convert a []interface{} OR a map[string]interface{} to properly typed values
-func jsonParamsToArgsRPC(rpcFunc *RPCFunc, paramsI interface{}) ([]reflect.Value, error) {
-	return jsonParamsToArgs(rpcFunc, paramsI, 0)
+func jsonParamsToArgsRPC(rpcFunc *RPCFunc, params *json.RawMessage) ([]reflect.Value, error) {
+	return jsonParamsToArgs(rpcFunc, *params, 0)
 }
 
 // Same as above, but with the first param the websocket connection
-func jsonParamsToArgsWS(rpcFunc *RPCFunc, paramsI interface{}, wsCtx types.WSRPCContext) ([]reflect.Value, error) {
-	values, err := jsonParamsToArgs(rpcFunc, paramsI, 1)
+func jsonParamsToArgsWS(rpcFunc *RPCFunc, params *json.RawMessage, wsCtx types.WSRPCContext) ([]reflect.Value, error) {
+	values, err := jsonParamsToArgs(rpcFunc, *params, 1)
 	if err != nil {
 		return nil, err
 	}

rpc/lib/types/types.go

@@ -8,19 +8,37 @@ import (
 )
 
 type RPCRequest struct {
-	JSONRPC string      `json:"jsonrpc"`
-	ID      string      `json:"id"`
-	Method  string      `json:"method"`
-	Params  interface{} `json:"params"` // must be map[string]interface{} or []interface{}
+	JSONRPC string           `json:"jsonrpc"`
+	ID      string           `json:"id"`
+	Method  string           `json:"method"`
+	Params  *json.RawMessage `json:"params"` // must be map[string]interface{} or []interface{}
 }
 
-func NewRPCRequest(id string, method string, params map[string]interface{}) RPCRequest {
+func NewRPCRequest(id string, method string, params json.RawMessage) RPCRequest {
 	return RPCRequest{
 		JSONRPC: "2.0",
 		ID:      id,
 		Method:  method,
-		Params:  params,
+		Params:  &params,
+	}
+}
+
+func MapToRequest(id string, method string, params map[string]interface{}) (RPCRequest, error) {
+	payload, err := json.Marshal(params)
+	if err != nil {
+		return RPCRequest{}, err
+	}
+	request := NewRPCRequest(id, method, payload)
+	return request, nil
+}
+
+func ArrayToRequest(id string, method string, params []interface{}) (RPCRequest, error) {
+	payload, err := json.Marshal(params)
+	if err != nil {
+		return RPCRequest{}, err
 	}
+	request := NewRPCRequest(id, method, payload)
+	return request, nil
 }
 
 //----------------------------------------