added support for batch requests

Author: Bas van Kervel

rpc/codec/codec.go

@@ -12,7 +12,7 @@ type Codec int
 // (de)serialization support for rpc interface
 type ApiCoder interface {
 	// Parse message to request from underlying stream
-	ReadRequest() (*shared.Request, error)
+	ReadRequest() ([]*shared.Request, bool, error)
 	// Parse response message from underlying stream
 	ReadResponse() (interface{}, error)
 	// Encode response to encoded form in underlying stream

rpc/codec/json.go

@@ -8,33 +8,53 @@ import (
 )
 
 const (
-	MAX_RESPONSE_SIZE = 64 * 1024
+	MAX_REQUEST_SIZE = 1024 * 1024
+	MAX_RESPONSE_SIZE = 1024 * 1024
 )
 
 // Json serialization support
 type JsonCodec struct {
 	c net.Conn
-	d *json.Decoder
-	e *json.Encoder
+	buffer []byte
+	bytesInBuffer int
 }
 
 // Create new JSON coder instance
 func NewJsonCoder(conn net.Conn) ApiCoder {
 	return &JsonCodec{
 		c: conn,
-		d: json.NewDecoder(conn),
-		e: json.NewEncoder(conn),
+		buffer: make([]byte, MAX_REQUEST_SIZE),
+		bytesInBuffer: 0,
 	}
 }
 
 // Serialize obj to JSON and write it to conn
-func (self *JsonCodec) ReadRequest() (*shared.Request, error) {
-	req := shared.Request{}
-	err := self.d.Decode(&req)
+func (self *JsonCodec) ReadRequest() (requests []*shared.Request, isBatch bool, err error) {
+	n, err := self.c.Read(self.buffer[self.bytesInBuffer:])
+	if err != nil {
+		self.bytesInBuffer = 0
+		return nil, false, err
+	}
+
+	self.bytesInBuffer += n
+
+	singleRequest := shared.Request{}
+	err = json.Unmarshal(self.buffer[:self.bytesInBuffer], &singleRequest)
 	if err == nil {
-		return &req, nil
+		self.bytesInBuffer = 0
+		requests := make([]*shared.Request, 1)
+		requests[0] = &singleRequest
+		return requests, false, nil
 	}
-	return nil, err
+
+	requests = make([]*shared.Request, 0)
+	err = json.Unmarshal(self.buffer[:self.bytesInBuffer], &requests)
+	if err == nil {
+		self.bytesInBuffer = 0
+		return requests, true, nil
+	}
+
+	return nil, false, err
 }
 
 func (self *JsonCodec) ReadResponse() (interface{}, error) {
@@ -66,7 +86,24 @@ func (self *JsonCodec) Encode(msg interface{}) ([]byte, error) {
 
 // Parse JSON data from conn to obj
 func (self *JsonCodec) WriteResponse(res interface{}) error {
-	return self.e.Encode(&res)
+	data, err := json.Marshal(res)
+	if err != nil {
+		self.c.Close()
+		return err
+	}
+
+	bytesWritten := 0
+
+	for bytesWritten < len(data) {
+		n, err := self.c.Write(data[bytesWritten:])
+		if err != nil {
+			self.c.Close()
+			return err
+		}
+		bytesWritten += n
+	}
+
+	return nil
 }
 
 // Close decoder and encoder

rpc/comms/comms.go

@@ -47,7 +47,7 @@ func handle(conn net.Conn, api shared.EthereumApi, c codec.Codec) {
 	codec := c.New(conn)
 
 	for {
-		req, err := codec.ReadRequest()
+		requests, isBatch, err := codec.ReadRequest()
 		if err == io.EOF {
 			codec.Close()
 			return
@@ -57,15 +57,35 @@ func handle(conn net.Conn, api shared.EthereumApi, c codec.Codec) {
 			return
 		}
 
-		var rpcResponse interface{}
-		res, err := api.Execute(req)
+		if isBatch {
+			responses := make([]*interface{}, len(requests))
+			responseCount := 0
+			for _, req := range requests {
+				res, err := api.Execute(req)
+				if req.Id != nil {
+					rpcResponse := shared.NewRpcResponse(req.Id, req.Jsonrpc, res, err)
+					responses[responseCount] = rpcResponse
+					responseCount += 1
+				}
+			}
 
-		rpcResponse = shared.NewRpcResponse(req.Id, req.Jsonrpc, res, err)
-		err = codec.WriteResponse(rpcResponse)
-		if err != nil {
-			glog.V(logger.Error).Infof("comms send err - %v\n", err)
-			codec.Close()
-			return
+			err = codec.WriteResponse(responses[:responseCount])
+			if err != nil {
+				glog.V(logger.Error).Infof("comms send err - %v\n", err)
+				codec.Close()
+				return
+			}
+		} else {
+			var rpcResponse interface{}
+			res, err := api.Execute(requests[0])
+
+			rpcResponse = shared.NewRpcResponse(requests[0].Id, requests[0].Jsonrpc, res, err)
+			err = codec.WriteResponse(rpcResponse)
+			if err != nil {
+				glog.V(logger.Error).Infof("comms send err - %v\n", err)
+				codec.Close()
+				return
+			}
 		}
 	}
 }