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libtdevnc/webclients/novnc/include/websock.js

361 lines
9.2 KiB

/*
* Websock: high-performance binary WebSockets
* Copyright (C) 2012 Joel Martin
* Licensed under LGPL-3 (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: false, plusplus: false */
/*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 () {
function get_INCLUDE_URI() {
return (typeof INCLUDE_URI !== "undefined") ?
INCLUDE_URI : "include/";
}
var start = "<script src='" + get_INCLUDE_URI(),
end = "'><\/script>", extra = "";
window.WEB_SOCKET_SWF_LOCATION = 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();
}
extra += start + "web-socket-js/swfobject.js" + end;
extra += start + "web-socket-js/web_socket.js" + end;
document.write(extra);
}());
}
function Websock() {
"use strict";
var api = {}, // Public API
websocket = null, // WebSocket object
rQ = [], // Receive queue
rQi = 0, // Receive queue index
rQmax = 10000, // Max receive queue size before compacting
sQ = [], // Send queue
eventHandlers = {
'message' : function() {},
'open' : function() {},
'close' : function() {},
'error' : function() {}
},
test_mode = false;
//
// Queue public functions
//
function get_sQ() {
return sQ;
}
function get_rQ() {
return rQ;
}
function get_rQi() {
return rQi;
}
function set_rQi(val) {
rQi = val;
}
function rQlen() {
return rQ.length - rQi;
}
function rQpeek8() {
return (rQ[rQi] );
}
function rQshift8() {
return (rQ[rQi++] );
}
function rQunshift8(num) {
if (rQi === 0) {
rQ.unshift(num);
} else {
rQi -= 1;
rQ[rQi] = num;
}
}
function rQshift16() {
return (rQ[rQi++] << 8) +
(rQ[rQi++] );
}
function rQshift32() {
return (rQ[rQi++] << 24) +
(rQ[rQi++] << 16) +
(rQ[rQi++] << 8) +
(rQ[rQi++] );
}
function rQshiftStr(len) {
if (typeof(len) === 'undefined') { len = rQlen(); }
var arr = rQ.slice(rQi, rQi + len);
rQi += len;
return arr.map(function (num) {
return String.fromCharCode(num); } ).join('');
}
function rQshiftBytes(len) {
if (typeof(len) === 'undefined') { len = rQlen(); }
rQi += len;
return rQ.slice(rQi-len, rQi);
}
function rQslice(start, end) {
if (end) {
return rQ.slice(rQi + start, rQi + end);
} else {
return rQ.slice(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.
function rQwait(msg, num, goback) {
var rQlen = rQ.length - rQi; // Skip rQlen() function call
if (rQlen < num) {
if (goback) {
if (rQi < goback) {
throw("rQwait cannot backup " + goback + " bytes");
}
rQi -= goback;
}
//Util.Debug(" waiting for " + (num-rQlen) +
// " " + msg + " byte(s)");
return true; // true means need more data
}
return false;
}
//
// Private utility routines
//
function encode_message() {
/* base64 encode */
return Base64.encode(sQ);
}
function decode_message(data) {
//Util.Debug(">> decode_message: " + data);
/* base64 decode */
rQ = rQ.concat(Base64.decode(data, 0));
//Util.Debug(">> decode_message, rQ: " + rQ);
}
//
// Public Send functions
//
function flush() {
if (websocket.bufferedAmount !== 0) {
Util.Debug("bufferedAmount: " + websocket.bufferedAmount);
}
if (websocket.bufferedAmount < api.maxBufferedAmount) {
//Util.Debug("arr: " + arr);
//Util.Debug("sQ: " + sQ);
if (sQ.length > 0) {
websocket.send(encode_message(sQ));
sQ = [];
}
return true;
} else {
Util.Info("Delaying send, bufferedAmount: " +
websocket.bufferedAmount);
return false;
}
}
// overridable for testing
function send(arr) {
//Util.Debug(">> send_array: " + arr);
sQ = sQ.concat(arr);
return flush();
}
function send_string(str) {
//Util.Debug(">> send_string: " + str);
api.send(str.split('').map(
function (chr) { return chr.charCodeAt(0); } ) );
}
//
// Other public functions
function recv_message(e) {
//Util.Debug(">> recv_message: " + e.data.length);
try {
decode_message(e.data);
if (rQlen() > 0) {
eventHandlers.message();
// Compact the receive queue
if (rQ.length > rQmax) {
//Util.Debug("Compacting receive queue");
rQ = rQ.slice(rQi);
rQi = 0;
}
} else {
Util.Debug("Ignoring empty message");
}
} catch (exc) {
if (typeof exc.stack !== 'undefined') {
Util.Warn("recv_message, caught exception: " + exc.stack);
} else if (typeof exc.description !== 'undefined') {
Util.Warn("recv_message, caught exception: " + exc.description);
} else {
Util.Warn("recv_message, caught exception:" + exc);
}
if (typeof exc.name !== 'undefined') {
eventHandlers.error(exc.name + ": " + exc.message);
} else {
eventHandlers.error(exc);
}
}
//Util.Debug("<< recv_message");
}
// Set event handlers
function on(evt, handler) {
eventHandlers[evt] = handler;
}
function init() {
rQ = [];
rQi = 0;
sQ = [];
websocket = null;
}
function open(uri) {
init();
if (test_mode) {
websocket = {};
} else {
websocket = new WebSocket(uri, 'base64');
// TODO: future native binary support
//websocket = new WebSocket(uri, ['binary', 'base64']);
}
websocket.onmessage = recv_message;
websocket.onopen = function() {
Util.Debug(">> WebSock.onopen");
if (websocket.protocol) {
Util.Info("Server chose sub-protocol: " + websocket.protocol);
} else {
Util.Error("Server select no sub-protocol!: " + websocket.protocol);
}
eventHandlers.open();
Util.Debug("<< WebSock.onopen");
};
websocket.onclose = function(e) {
Util.Debug(">> WebSock.onclose");
eventHandlers.close(e);
Util.Debug("<< WebSock.onclose");
};
websocket.onerror = function(e) {
Util.Debug(">> WebSock.onerror: " + e);
eventHandlers.error(e);
Util.Debug("<< WebSock.onerror");
};
}
function close() {
if (websocket) {
if ((websocket.readyState === WebSocket.OPEN) ||
(websocket.readyState === WebSocket.CONNECTING)) {
Util.Info("Closing WebSocket connection");
websocket.close();
}
websocket.onmessage = function (e) { return; };
}
}
// Override internal functions for testing
// Takes a send function, returns reference to recv function
function testMode(override_send) {
test_mode = true;
api.send = override_send;
api.close = function () {};
return recv_message;
}
function constructor() {
// Configuration settings
api.maxBufferedAmount = 200;
// Direct access to send and receive queues
api.get_sQ = get_sQ;
api.get_rQ = get_rQ;
api.get_rQi = get_rQi;
api.set_rQi = set_rQi;
// Routines to read from the receive queue
api.rQlen = rQlen;
api.rQpeek8 = rQpeek8;
api.rQshift8 = rQshift8;
api.rQunshift8 = rQunshift8;
api.rQshift16 = rQshift16;
api.rQshift32 = rQshift32;
api.rQshiftStr = rQshiftStr;
api.rQshiftBytes = rQshiftBytes;
api.rQslice = rQslice;
api.rQwait = rQwait;
api.flush = flush;
api.send = send;
api.send_string = send_string;
api.on = on;
api.init = init;
api.open = open;
api.close = close;
api.testMode = testMode;
return api;
}
return constructor();
}