plugeth/lib/websocket.js
2015-01-14 12:01:11 +01:00

99 lines
2.9 KiB
JavaScript

/*
This file is part of ethereum.js.
ethereum.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.
ethereum.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 ethereum.js. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file websocket.js
* @authors:
* Jeffrey Wilcke <jeff@ethdev.com>
* Marek Kotewicz <marek@ethdev.com>
* Marian Oancea <marian@ethdev.com>
* @date 2014
*/
// TODO: is these line is supposed to be here?
if (process.env.NODE_ENV !== 'build') {
var WebSocket = require('ws'); // jshint ignore:line
}
/**
* WebSocketProvider object prototype is implementing 'provider protocol'
* Should be used when we want to connect to ethereum backend over websockets
* It's compatible with go client
* The constructor allows to specify host uri
*/
var WebSocketProvider = function(host) {
// onmessage handlers
this.handlers = [];
// queue will be filled with messages if send is invoked before the ws is ready
this.queued = [];
this.ready = false;
this.ws = new WebSocket(host);
var self = this;
this.ws.onmessage = function(event) {
for(var i = 0; i < self.handlers.length; i++) {
self.handlers[i].call(self, JSON.parse(event.data), event);
}
};
this.ws.onopen = function() {
self.ready = true;
for (var i = 0; i < self.queued.length; i++) {
// Resend
self.send(self.queued[i]);
}
};
};
/// Prototype object method
/// Should be called when we want to send single api request to server
/// Asynchronous, it's using websockets
/// Response for the call will be received by ws.onmessage
/// @param payload is inner message object
WebSocketProvider.prototype.send = function(payload) {
if (this.ready) {
var data = JSON.stringify(payload);
this.ws.send(data);
} else {
this.queued.push(payload);
}
};
/// Prototype object method
/// Should be called to add handlers
WebSocketProvider.prototype.onMessage = function(handler) {
this.handlers.push(handler);
};
/// Prototype object method
/// Should be called to close websockets connection
WebSocketProvider.prototype.unload = function() {
this.ws.close();
};
/// Prototype object property
/// Should be used to set message handlers for this provider
Object.defineProperty(WebSocketProvider.prototype, "onmessage", {
set: function(provider) { this.onMessage(provider); }
});
if (typeof(module) !== "undefined")
module.exports = WebSocketProvider;