// sendRPC sends an RPC out to the wire. // Returns the response (for now, as the call is synchronous). func (c *Client) sendRPC(rpc hrpc.Call) error { // Header. c.id++ reqheader := &pb.RequestHeader{ CallId: &c.id, MethodName: proto.String(rpc.GetName()), RequestParam: proto.Bool(true), } payload, err := rpc.Serialize() if err != nil { return fmt.Errorf("Failed to serialize RPC: %s", err) } payloadLen := proto.EncodeVarint(uint64(len(payload))) headerData, err := proto.Marshal(reqheader) if err != nil { return fmt.Errorf("Failed to marshal Get request: %s", err) } buf := make([]byte, 5, 4+1+len(headerData)+len(payloadLen)+len(payload)) binary.BigEndian.PutUint32(buf, uint32(cap(buf)-4)) buf[4] = byte(len(headerData)) buf = append(buf, headerData...) buf = append(buf, payloadLen...) buf = append(buf, payload...) c.sentRPCsMutex.Lock() c.sentRPCs[c.id] = rpc c.sentRPCsMutex.Unlock() err = c.write(buf) if err != nil { return UnrecoverableError{err} } return nil }