steem-block-db/jsonrpc.go

107 lines
2.1 KiB
Go

package main
// thanks to https://github.com/onrik/ethrpc/blob/master/ethrpc.go for
// example
import (
"bytes"
"encoding/json"
"fmt"
log "github.com/sirupsen/logrus"
"io"
"io/ioutil"
"net/http"
)
type httpRPCClient interface {
Post(url string, contentType string, body io.Reader) (*http.Response, error)
}
type JSONRPCError struct {
Code int `json:"code"`
Message string `json:"message"`
}
func (err JSONRPCError) Error() string {
return fmt.Sprintf("Error %d (%s)", err.Code, err.Message)
}
type JSONRPCResponse struct {
ID string `json:"id"`
JSONRPC string `json:"jsonrpc"`
Result json.RawMessage `json:"result"`
Error *JSONRPCError `json:"error"`
}
type JSONRPCRequest struct {
ID string `json:"id"`
JSONRPC string `json:"jsonrpc"`
Method string `json:"method"`
Params []json.RawMessage `json:"params"`
}
type JSONRPC struct {
url string
client httpRPCClient
Debug bool
log *log.Logger
}
// New create new rpc client with given url
func NewJSONRPC(url string, options ...func(rpc *JSONRPC)) *JSONRPC {
rpc := &JSONRPC{
url: url,
client: http.DefaultClient,
}
rpc.log = log.New()
for _, option := range options {
option(rpc)
}
return rpc
}
// Call returns raw response of method call
func (rpc *JSONRPC) Call(method string, params ...json.RawMessage) (json.RawMessage, error) {
request := JSONRPCRequest{
ID: "1",
JSONRPC: "2.0",
Method: method,
Params: params,
}
body, err := json.Marshal(request)
if err != nil {
return nil, err
}
response, err := rpc.client.Post(rpc.url, "application/json", bytes.NewBuffer(body))
if response != nil {
defer response.Body.Close()
}
if err != nil {
return nil, err
}
data, err := ioutil.ReadAll(response.Body)
if err != nil {
return nil, err
}
if rpc.Debug {
rpc.log.Println(fmt.Sprintf("%s\nRequest: %s\nResponse: %s\n", method, body, data))
}
resp := new(JSONRPCResponse)
if err := json.Unmarshal(data, resp); err != nil {
return nil, err
}
if resp.Error != nil {
return nil, *resp.Error
}
return resp.Result, nil
}