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/*
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 autoprovider.js
* @authors:
* Marek Kotewicz <marek@ethdev.com>
* Marian Oancea <marian@ethdev.com>
* @date 2014
*/
/*
* @brief if qt object is available, uses QtProvider,
* if not tries to connect over websockets
* if it fails, it uses HttpRpcProvider
*/
// TODO: is these line is supposed to be here?
if (process.env.NODE_ENV !== 'build') {
var WebSocket = require('ws'); // jshint ignore:line
var web3 = require('./web3'); // jshint ignore:line
}
/**
* AutoProvider object prototype is implementing 'provider protocol'
* Automatically tries to setup correct provider(Qt, WebSockets or HttpRpc)
* First it checkes if we are ethereum browser (if navigator.qt object is available)
* if yes, we are using QtProvider
* if no, we check if it is possible to establish websockets connection with ethereum (ws://localhost:40404/eth is default)
* if it's not possible, we are using httprpc provider (http://localhost:8080)
* The constructor allows you to specify uris on which we are trying to connect over http or websockets
* You can do that by passing objects with fields httrpc and websockets
*/
var AutoProvider = function (userOptions) {
if (web3.haveProvider()) {
return;
}
// before we determine what provider we are, we have to cache request
this.sendQueue = [];
this.onmessageQueue = [];
if (navigator.qt) {
this.provider = new web3.providers.QtProvider();
return;
}
userOptions = userOptions || {};
var options = {
httprpc: userOptions.httprpc || 'http://localhost:8080',
websockets: userOptions.websockets || 'ws://localhost:40404/eth'
};
var self = this;
var closeWithSuccess = function (success) {
ws.close();
if (success) {
self.provider = new web3.providers.WebSocketProvider(options.websockets);
} else {
self.provider = new web3.providers.HttpRpcProvider(options.httprpc);
self.poll = self.provider.poll.bind(self.provider);
}
self.sendQueue.forEach(function (payload) {
self.provider(payload);
});
self.onmessageQueue.forEach(function (handler) {
self.provider.onmessage = handler;
});
};
var ws = new WebSocket(options.websockets);
ws.onopen = function() {
closeWithSuccess(true);
};
ws.onerror = function() {
closeWithSuccess(false);
};
};
/// Sends message forward to the provider, that is being used
/// if provider is not yet set, enqueues the message
AutoProvider.prototype.send = function (payload) {
if (this.provider) {
this.provider.send(payload);
return;
}
this.sendQueue.push(payload);
};
/// On incoming message sends the message to the provider that is currently being used
Object.defineProperty(AutoProvider.prototype, 'onmessage', {
set: function (handler) {
if (this.provider) {
this.provider.onmessage = handler;
return;
}
this.onmessageQueue.push(handler);
}
});
module.exports = AutoProvider;
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