web3.js/lib/web3/syncing.js

93 lines
2.7 KiB
JavaScript

/*
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 syncing.js
* @authors:
* Fabian Vogelsteller <fabian@ethdev.com>
* @date 2015
*/
var formatters = require('./formatters');
var utils = require('../utils/utils');
/**
Adds the callback and sets up the methods, to iterate over the results.
@method pollSyncing
@param {Object} self
*/
var pollSyncing = function(self) {
var lastSyncState = false;
var onMessage = function (error, sync) {
if (error) {
return self.callbacks.forEach(function (callback) {
callback(error);
});
}
if(utils.isObject(sync))
sync = formatters.outputSyncingFormatter(sync);
self.callbacks.forEach(function (callback) {
if (lastSyncState !== sync) {
// call the callback with true first so the app can stop anything, before receiving the sync data
if(!lastSyncState && utils.isObject(sync))
callback(null, true);
// call on the next CPU cycle, so the actions of the sync stop can be processes first
setTimeout(function() {
callback(null, sync);
}, 1);
lastSyncState = sync;
}
});
};
self.requestManager.startPolling({
method: 'eth_syncing',
params: [],
}, self.pollId, onMessage, self.stopWatching.bind(self));
};
var IsSyncing = function (web3, callback) {
this._web3 = web3;
this.requestManager = web3._requestManager;
this.pollId = 'syncPoll_'+ Math.floor(Math.random() * 1000);
this.callbacks = [];
this.addCallback(callback);
pollSyncing(this);
return this;
};
IsSyncing.prototype.addCallback = function (callback) {
if(callback)
this.callbacks.push(callback);
return this;
};
IsSyncing.prototype.stopWatching = function () {
this._web3._requestManager.stopPolling(this.pollId);
this.callbacks = [];
};
module.exports = IsSyncing;