Merge pull request #37 from etclabscore/feat/server-method-alias

jsonrpc: add RPCServer.AliasMethod method

Author: magik6k

handler.go

@@ -194,10 +194,16 @@ func (s *RPCServer) handle(ctx context.Context, req request, w func(func(io.Writ
 
 	handler, ok := s.methods[req.Method]
 	if !ok {
-		rpcError(w, &req, rpcMethodNotFound, fmt.Errorf("method '%s' not found", req.Method))
-		stats.Record(ctx, metrics.RPCInvalidMethod.M(1))
-		done(false)
-		return
+		aliasTo, ok := s.aliasedMethods[req.Method]
+		if ok {
+			handler, ok = s.methods[aliasTo]
+		}
+		if !ok {
+			rpcError(w, &req, rpcMethodNotFound, fmt.Errorf("method '%s' not found", req.Method))
+			stats.Record(ctx, metrics.RPCInvalidMethod.M(1))
+			done(false)
+			return
+		}
 	}
 
 	if len(req.Params) != handler.nParams {

server.go

@@ -19,7 +19,11 @@ const (
 
 // RPCServer provides a jsonrpc 2.0 http server handler
 type RPCServer struct {
-	methods map[string]rpcHandler
+	methods        map[string]rpcHandler
+
+	// aliasedMethods contains a map of alias:original method names.
+	// These are used as fallbacks if a method is not found by the given method name.
+	aliasedMethods map[string]string
 
 	paramDecoders map[reflect.Type]ParamDecoder
 
@@ -35,6 +39,7 @@ func NewServer(opts ...ServerOption) *RPCServer {
 
 	return &RPCServer{
 		methods:        map[string]rpcHandler{},
+		aliasedMethods: map[string]string{},
 		paramDecoders:  config.paramDecoders,
 		maxRequestSize: config.maxRequestSize,
 	}
@@ -123,4 +128,8 @@ func (s *RPCServer) Register(namespace string, handler interface{}) {
 	s.register(namespace, handler)
 }
 
+func (s *RPCServer) AliasMethod(alias, original string) {
+	s.aliasedMethods[alias] = original
+}
+
 var _ error = &respError{}