// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package rpc implements the Ethereum JSON-RPC API.
package rpc
import (
"encoding/json"
"fmt"
"reflect"
"sync/atomic"
"github.com/ethereum/go-ethereum/rpc/comms"
"github.com/ethereum/go-ethereum/rpc/shared"
)
// Xeth is a native API interface to a remote node.
type Xeth struct {
client comms.EthereumClient
reqId uint32
}
// NewXeth constructs a new native API interface to a remote node.
func NewXeth(client comms.EthereumClient) *Xeth {
return &Xeth{
client: client,
}
}
// Call invokes a method with the given parameters are the remote node.
func (self *Xeth) Call(method string, params []interface{}) (map[string]interface{}, error) {
// Assemble the json RPC request
data, err := json.Marshal(params)
if err != nil {
return nil, err
}
req := &shared.Request{
Id: atomic.AddUint32(&self.reqId, 1),
Jsonrpc: "2.0",
Method: method,
Params: data,
}
// Send the request over and retrieve the response
if err := self.client.Send(req); err != nil {
return nil, err
}
res, err := self.client.Recv()
if err != nil {
return nil, err
}
// Ensure the response is valid, and extract the results
success, isSuccessResponse := res.(*shared.SuccessResponse)
failure, isFailureResponse := res.(*shared.ErrorResponse)
switch {
case isFailureResponse:
return nil, fmt.Errorf("Method invocation failed: %v", failure.Error)
case isSuccessResponse:
return success.Result.(map[string]interface{}), nil
default:
return nil, fmt.Errorf("Invalid response type: %v", reflect.TypeOf(res))
}
}
