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libtdevnc/webclients/novnc/include/websock.js

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/*
* Websock: high-performance binary WebSockets
* Copyright (C) 2012 Joel Martin
* Licensed under MPL 2.0 (see LICENSE.txt)
*
* Websock is similar to the standard WebSocket object but Websock
* enables communication with raw TCP sockets (i.e. the binary stream)
* via websockify. This is accomplished by base64 encoding the data
* stream between Websock and websockify.
*
* Websock has built-in receive queue buffering; the message event
* does not contain actual data but is simply a notification that
* there is new data available. Several rQ* methods are available to
* read binary data off of the receive queue.
*/
/*jslint browser: true, bitwise: true */
/*global Util, Base64 */
// Load Flash WebSocket emulator if needed
// To force WebSocket emulator even when native WebSocket available
//window.WEB_SOCKET_FORCE_FLASH = true;
// To enable WebSocket emulator debug:
//window.WEB_SOCKET_DEBUG=1;
if (window.WebSocket && !window.WEB_SOCKET_FORCE_FLASH) {
Websock_native = true;
} else if (window.MozWebSocket && !window.WEB_SOCKET_FORCE_FLASH) {
Websock_native = true;
window.WebSocket = window.MozWebSocket;
} else {
/* no builtin WebSocket so load web_socket.js */
Websock_native = false;
(function () {
window.WEB_SOCKET_SWF_LOCATION = Util.get_include_uri() +
"web-socket-js/WebSocketMain.swf";
if (Util.Engine.trident) {
Util.Debug("Forcing uncached load of WebSocketMain.swf");
window.WEB_SOCKET_SWF_LOCATION += "?" + Math.random();
}
Util.load_scripts(["web-socket-js/swfobject.js",
"web-socket-js/web_socket.js"]);
})();
}
function Websock() {
"use strict";
this._websocket = null; // WebSocket object
this._rQ = []; // Receive queue
this._rQi = 0; // Receive queue index
this._rQmax = 10000; // Max receive queue size before compacting
this._sQ = []; // Send queue
this._mode = 'base64'; // Current WebSocket mode: 'binary', 'base64'
this.maxBufferedAmount = 200;
this._eventHandlers = {
'message': function () {},
'open': function () {},
'close': function () {},
'error': function () {}
};
}
(function () {
"use strict";
Websock.prototype = {
// Getters and Setters
get_sQ: function () {
return this._sQ;
},
get_rQ: function () {
return this._rQ;
},
get_rQi: function () {
return this._rQi;
},
set_rQi: function (val) {
this._rQi = val;
},
// Receive Queue
rQlen: function () {
return this._rQ.length - this._rQi;
},
rQpeek8: function () {
return this._rQ[this._rQi];
},
rQshift8: function () {
return this._rQ[this._rQi++];
},
rQskip8: function () {
this._rQi++;
},
rQskipBytes: function (num) {
this._rQi += num;
},
rQunshift8: function (num) {
if (this._rQi === 0) {
this._rQ.unshift(num);
} else {
this._rQi--;
this._rQ[this._rQi] = num;
}
},
rQshift16: function () {
return (this._rQ[this._rQi++] << 8) +
this._rQ[this._rQi++];
},
rQshift32: function () {
return (this._rQ[this._rQi++] << 24) +
(this._rQ[this._rQi++] << 16) +
(this._rQ[this._rQi++] << 8) +
this._rQ[this._rQi++];
},
rQshiftStr: function (len) {
if (typeof(len) === 'undefined') { len = this.rQlen(); }
var arr = this._rQ.slice(this._rQi, this._rQi + len);
this._rQi += len;
return String.fromCharCode.apply(null, arr);
},
rQshiftBytes: function (len) {
if (typeof(len) === 'undefined') { len = this.rQlen(); }
this._rQi += len;
return this._rQ.slice(this._rQi - len, this._rQi);
},
rQslice: function (start, end) {
if (end) {
return this._rQ.slice(this._rQi + start, this._rQi + end);
} else {
return this._rQ.slice(this._rQi + start);
}
},
// Check to see if we must wait for 'num' bytes (default to FBU.bytes)
// to be available in the receive queue. Return true if we need to
// wait (and possibly print a debug message), otherwise false.
rQwait: function (msg, num, goback) {
var rQlen = this._rQ.length - this._rQi; // Skip rQlen() function call
if (rQlen < num) {
if (goback) {
if (this._rQi < goback) {
throw new Error("rQwait cannot backup " + goback + " bytes");
}
this._rQi -= goback;
}
return true; // true means need more data
}
return false;
},
// Send Queue
flush: function () {
if (this._websocket.bufferedAmount !== 0) {
Util.Debug("bufferedAmount: " + this._websocket.bufferedAmount);
}
if (this._websocket.bufferedAmount < this.maxBufferedAmount) {
if (this._sQ.length > 0) {
this._websocket.send(this._encode_message());
this._sQ = [];
}
return true;
} else {
Util.Info("Delaying send, bufferedAmount: " +
this._websocket.bufferedAmount);
return false;
}
},
send: function (arr) {
this._sQ = this._sQ.concat(arr);
return this.flush();
},
send_string: function (str) {
this.send(str.split('').map(function (chr) {
return chr.charCodeAt(0);
}));
},
// Event Handlers
on: function (evt, handler) {
this._eventHandlers[evt] = handler;
},
init: function (protocols, ws_schema) {
this._rQ = [];
this._rQi = 0;
this._sQ = [];
this._websocket = null;
// Check for full typed array support
var bt = false;
if (('Uint8Array' in window) &&
('set' in Uint8Array.prototype)) {
bt = true;
}
// Check for full binary type support in WebSockets
// Inspired by:
// https://github.com/Modernizr/Modernizr/issues/370
// https://github.com/Modernizr/Modernizr/blob/master/feature-detects/websockets/binary.js
var wsbt = false;
try {
if (bt && ('binaryType' in WebSocket.prototype ||
!!(new WebSocket(ws_schema + '://.').binaryType))) {
Util.Info("Detected binaryType support in WebSockets");
wsbt = true;
}
} catch (exc) {
// Just ignore failed test localhost connection
}
// Default protocols if not specified
if (typeof(protocols) === "undefined") {
if (wsbt) {
protocols = ['binary', 'base64'];
} else {
protocols = 'base64';
}
}
if (!wsbt) {
if (protocols === 'binary') {
throw new Error('WebSocket binary sub-protocol requested but not supported');
}
if (typeof(protocols) === 'object') {
var new_protocols = [];
for (var i = 0; i < protocols.length; i++) {
if (protocols[i] === 'binary') {
Util.Error('Skipping unsupported WebSocket binary sub-protocol');
} else {
new_protocols.push(protocols[i]);
}
}
if (new_protocols.length > 0) {
protocols = new_protocols;
} else {
throw new Error("Only WebSocket binary sub-protocol was requested and is not supported.");
}
}
}
return protocols;
},
open: function (uri, protocols) {
var ws_schema = uri.match(/^([a-z]+):\/\//)[1];
protocols = this.init(protocols, ws_schema);
this._websocket = new WebSocket(uri, protocols);
if (protocols.indexOf('binary') >= 0) {
this._websocket.binaryType = 'arraybuffer';
}
this._websocket.onmessage = this._recv_message.bind(this);
this._websocket.onopen = (function () {
Util.Debug('>> WebSock.onopen');
if (this._websocket.protocol) {
this._mode = this._websocket.protocol;
Util.Info("Server choose sub-protocol: " + this._websocket.protocol);
} else {
this._mode = 'base64';
Util.Error('Server select no sub-protocol!: ' + this._websocket.protocol);
}
this._eventHandlers.open();
Util.Debug("<< WebSock.onopen");
}).bind(this);
this._websocket.onclose = (function (e) {
Util.Debug(">> WebSock.onclose");
this._eventHandlers.close(e);
Util.Debug("<< WebSock.onclose");
}).bind(this);
this._websocket.onerror = (function (e) {
Util.Debug(">> WebSock.onerror: " + e);
this._eventHandlers.error(e);
Util.Debug("<< WebSock.onerror: " + e);
}).bind(this);
},
close: function () {
if (this._websocket) {
if ((this._websocket.readyState === WebSocket.OPEN) ||
(this._websocket.readyState === WebSocket.CONNECTING)) {
Util.Info("Closing WebSocket connection");
this._websocket.close();
}
this._websocket.onmessage = function (e) { return; };
}
},
// private methods
_encode_message: function () {
if (this._mode === 'binary') {
// Put in a binary arraybuffer
return (new Uint8Array(this._sQ)).buffer;
} else {
// base64 encode
return Base64.encode(this._sQ);
}
},
_decode_message: function (data) {
if (this._mode === 'binary') {
// push arraybuffer values onto the end
var u8 = new Uint8Array(data);
for (var i = 0; i < u8.length; i++) {
this._rQ.push(u8[i]);
}
} else {
// base64 decode and concat to end
this._rQ = this._rQ.concat(Base64.decode(data, 0));
}
},
_recv_message: function (e) {
try {
this._decode_message(e.data);
if (this.rQlen() > 0) {
this._eventHandlers.message();
// Compact the receive queue
if (this._rQ.length > this._rQmax) {
this._rQ = this._rQ.slice(this._rQi);
this._rQi = 0;
}
} else {
Util.Debug("Ignoring empty message");
}
} catch (exc) {
var exception_str = "";
if (exc.name) {
exception_str += "\n name: " + exc.name + "\n";
exception_str += " message: " + exc.message + "\n";
}
if (typeof exc.description !== 'undefined') {
exception_str += " description: " + exc.description + "\n";
}
if (typeof exc.stack !== 'undefined') {
exception_str += exc.stack;
}
if (exception_str.length > 0) {
Util.Error("recv_message, caught exception: " + exception_str);
} else {
Util.Error("recv_message, caught exception: " + exc);
}
if (typeof exc.name !== 'undefined') {
this._eventHandlers.error(exc.name + ": " + exc.message);
} else {
this._eventHandlers.error(exc);
}
}
}
};
})();