openethereum/js/src/api/transport/jsonRpcBase.js
2017-04-06 17:13:53 +02:00

146 lines
3.1 KiB
JavaScript

// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity 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 General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
import EventEmitter from 'eventemitter3';
import { Logging } from '../subscriptions';
export default class JsonRpcBase extends EventEmitter {
constructor () {
super();
this._id = 1;
this._debug = false;
this._connected = false;
this._middlewareList = Promise.resolve([]);
}
encode (method, params) {
const json = JSON.stringify({
jsonrpc: '2.0',
method: method,
params: params,
id: this._id++
});
return json;
}
addMiddleware (Middleware) {
this._middlewareList = Promise
.all([
Middleware,
this._middlewareList
])
.then(([Middleware, middlewareList]) => {
// Do nothing if `handlerPromise` resolves to a null-y value.
if (Middleware == null) {
return middlewareList;
}
// don't mutate the original array
return middlewareList.concat([new Middleware(this)]);
});
}
_wrapSuccessResult (result) {
return {
id: this._id,
jsonrpc: '2.0',
result
};
}
_wrapErrorResult (error) {
return {
id: this._id,
jsonrpc: '2.0',
error: {
code: error.code,
message: error.text
}
};
}
execute (method, ...params) {
return this._middlewareList.then((middlewareList) => {
for (const middleware of middlewareList) {
const res = middleware.handle(method, params);
if (res != null) {
return Promise
.resolve(res)
.then((res) => {
const result = this._wrapSuccessResult(res);
const json = this.encode(method, params);
Logging.send(method, params, { json, result });
return res;
});
}
}
return this._execute(method, params);
});
}
_execute () {
throw new Error('Missing implementation of JsonRpcBase#_execute');
}
_setConnected () {
if (!this._connected) {
this._connected = true;
this.emit('open');
}
}
_setDisconnected () {
if (this._connected) {
this._connected = false;
this.emit('close');
}
}
get id () {
return this._id;
}
get isDebug () {
return this._debug;
}
get isConnected () {
return this._connected;
}
setDebug (flag) {
this._debug = flag;
}
error (error) {
if (this.isDebug) {
console.error(error);
}
}
log (log) {
if (this.isDebug) {
console.log(log);
}
}
}