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