/*
This file is part of web3.js.
web3.js 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.
web3.js 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 web3.js. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file jsonrpc.js
* @authors:
* Fabian Vogelsteller <fabian@ethereum.org>
* Marek Kotewicz <marek@ethdev.com>
* Aaron Kumavis <aaron@kumavis.me>
* @date 2015
*/
"use strict";
// Initialize Jsonrpc as a simple object with utility functions.
var Jsonrpc = {
// This is the starting counter for the Jsonrpc.id.
// Pick a random number between 0 and the maximum safe integer
messageId: Math.floor(Math.random() * Number.MAX_SAFE_INTEGER)
};
/**
* Should be called to valid json create payload object
*
* @method toPayload
* @param {Function} method of jsonrpc call, required
* @param {Array} params, an array of method params, optional
* @returns {Object} valid jsonrpc payload object
*/
Jsonrpc.toPayload = function (method, params) {
if (!method) {
throw new Error('JSONRPC method should be specified for params: "'+ JSON.stringify(params) +'"!');
}
if(Jsonrpc.messageId === Number.MAX_SAFE_INTEGER) {
// if the maximum safe integer has been reached, restart from a random number
Jsonrpc.messageId = Math.floor(Math.random() * Number.MAX_SAFE_INTEGER)
}
else {
// advance message ID
Jsonrpc.messageId++;
}
return {
jsonrpc: '2.0',
id: Jsonrpc.messageId,
method: method,
params: params || []
};
};
/**
* Should be called to check if jsonrpc response is valid
*
* @method isValidResponse
* @param {Object}
* @returns {Boolean} true if response is valid, otherwise false
*/
Jsonrpc.isValidResponse = function (response) {
return Array.isArray(response) ? response.every(validateSingleMessage) : validateSingleMessage(response);
function validateSingleMessage(message){
return !!message &&
!message.error &&
message.jsonrpc === '2.0' &&
(typeof message.id === 'number' || typeof message.id === 'string') &&
message.result !== undefined; // only undefined is not valid json object
}
};
/**
* Should be called to create batch payload object
*
* @method toBatchPayload
* @param {Array} messages, an array of objects with method (required) and params (optional) fields
* @returns {Array} batch payload
*/
Jsonrpc.toBatchPayload = function (messages) {
return messages.map(function (message) {
return Jsonrpc.toPayload(message.method, message.params);
});
};
module.exports = Jsonrpc;