xeth, rpc: implement eth_estimateGas. Closes #930

1 files changed, 21 insertions, 4 deletions

diff --git a/rpc/api.go b/rpc/api.go
index d53a9917d..774d26ea2 100644
--- a/rpc/api.go
+++ b/rpc/api.go
@@ -186,16 +186,24 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 			return err
 		}
 		*reply = v
-	case "eth_call":
-		args := new(CallArgs)
-		if err := json.Unmarshal(req.Params, &args); err != nil {
+	case "eth_estimateGas":
+		_, gas, err := api.doCall(req.Params)
+		if err != nil {
 			return err
 		}
 
-		v, err := api.xethAtStateNum(args.BlockNumber).Call(args.From, args.To, args.Value.String(), args.Gas.String(), args.GasPrice.String(), args.Data)
+		// TODO unwrap the parent method's ToHex call
+		if len(gas) == 0 {
+			*reply = newHexData([]byte{})
+		} else {
+			*reply = newHexData(gas)
+		}
+	case "eth_call":
+		v, _, err := api.doCall(req.Params)
 		if err != nil {
 			return err
 		}
+
 		// TODO unwrap the parent method's ToHex call
 		if v == "0x0" {
 			*reply = newHexData([]byte{})
@@ -571,3 +579,12 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 	glog.V(logger.Detail).Infof("Reply: %T %s\n", reply, reply)
 	return nil
 }
+
+func (api *EthereumApi) doCall(params json.RawMessage) (string, string, error) {
+	args := new(CallArgs)
+	if err := json.Unmarshal(params, &args); err != nil {
+		return "", "", err
+	}
+
+	return api.xethAtStateNum(args.BlockNumber).Call(args.From, args.To, args.Value.String(), args.Gas.String(), args.GasPrice.String(), args.Data)
+}