Cleanup: WebSocket Helper

File: websock.js
Tests Added: True
Changes:
- Cleaned up JSHint errors
- Converted to normal JS constructor pattern with "private" fields and
  methods now simply being prepended by underscores
- Added a "bind" polyfill for use in PhantomJS 1.x in util.js
- Added FakeWebSocket to fill in for actual WebSocket objects when
  testing
- Made exception handler actually log exception name and message,
  to console, in addition to stack trace
This commit is contained in:
Solly Ross
2014-05-22 16:57:55 -04:00
parent ee7d4c61c6
commit 2cccf7530c
3 changed files with 873 additions and 345 deletions

View File

@@ -14,7 +14,7 @@
* read binary data off of the receive queue.
*/
/*jslint browser: true, bitwise: false, plusplus: false */
/*jslint browser: true, bitwise: true */
/*global Util, Base64 */
@@ -43,382 +43,334 @@ if (window.WebSocket && !window.WEB_SOCKET_FORCE_FLASH) {
}
Util.load_scripts(["web-socket-js/swfobject.js",
"web-socket-js/web_socket.js"]);
}());
})();
}
function Websock() {
"use strict";
"use strict";
var api = {}, // Public API
websocket = null, // WebSocket object
mode = 'base64', // Current WebSocket mode: 'binary', 'base64'
rQ = [], // Receive queue
rQi = 0, // Receive queue index
rQmax = 10000, // Max receive queue size before compacting
sQ = [], // Send queue
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
eventHandlers = {
'message' : function() {},
'open' : function() {},
'close' : function() {},
'error' : function() {}
},
this._mode = 'base64'; // Current WebSocket mode: 'binary', 'base64'
this.maxBufferedAmount = 200;
test_mode = false;
//
// Queue public functions
//
function get_sQ() {
return sQ;
this._eventHandlers = {
'message': function () {},
'open': function () {},
'close': function () {},
'error': function () {}
};
}
function get_rQ() {
return rQ;
}
function get_rQi() {
return rQi;
}
function set_rQi(val) {
rQi = val;
}
(function () {
"use strict";
Websock.prototype = {
// Getters and Setters
get_sQ: function () {
return this._sQ;
},
function rQlen() {
return rQ.length - rQi;
}
get_rQ: function () {
return this._rQ;
},
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;
}
get_rQi: function () {
return this._rQi;
},
}
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 String.fromCharCode.apply(null, arr);
}
function rQshiftBytes(len) {
if (typeof(len) === 'undefined') { len = rQlen(); }
rQi += len;
return rQ.slice(rQi-len, rQi);
}
set_rQi: function (val) {
this._rQi = val;
},
function rQslice(start, end) {
if (end) {
return rQ.slice(rQi + start, rQi + end);
} else {
return rQ.slice(rQi + start);
}
}
// Receive Queue
rQlen: function () {
return this._rQ.length - this._rQi;
},
// 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");
rQpeek8: function () {
return this._rQ[this._rQi];
},
rQshift8: function () {
return this._rQ[this._rQi++];
},
rQunshift8: function (num) {
if (this._rQi === 0) {
this._rQ.unshift(num);
} else {
this._rQi--;
this._rQ[this._rQi] = num;
}
rQi -= goback;
}
//Util.Debug(" waiting for " + (num-rQlen) +
// " " + msg + " byte(s)");
return true; // true means need more data
}
return false;
}
},
//
// Private utility routines
//
rQshift16: function () {
return (this._rQ[this._rQi++] << 8) +
this._rQ[this._rQi++];
},
function encode_message() {
if (mode === 'binary') {
// Put in a binary arraybuffer
return (new Uint8Array(sQ)).buffer;
} else {
// base64 encode
return Base64.encode(sQ);
}
}
rQshift32: function () {
return (this._rQ[this._rQi++] << 24) +
(this._rQ[this._rQi++] << 16) +
(this._rQ[this._rQi++] << 8) +
this._rQ[this._rQi++];
},
function decode_message(data) {
//Util.Debug(">> decode_message: " + data);
if (mode === 'binary') {
// push arraybuffer values onto the end
var u8 = new Uint8Array(data);
for (var i = 0; i < u8.length; i++) {
rQ.push(u8[i]);
}
} else {
// base64 decode and concat to the end
rQ = rQ.concat(Base64.decode(data, 0));
}
//Util.Debug(">> decode_message, rQ: " + rQ);
}
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);
},
//
// 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;
rQslice: function (start, end) {
if (end) {
return this._rQ.slice(this._rQi + start, this._rQi + end);
} else {
return this._rQ.slice(this._rQi + start);
}
} 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");
}
},
// 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;
},
// Set event handlers
function on(evt, handler) {
eventHandlers[evt] = handler;
}
// Send Queue
function init(protocols, ws_schema) {
rQ = [];
rQi = 0;
sQ = [];
websocket = null;
flush: function () {
if (this._websocket.bufferedAmount !== 0) {
Util.Debug("bufferedAmount: " + this._websocket.bufferedAmount);
}
var bt = false,
wsbt = false,
try_binary = false;
if (this._websocket.bufferedAmount < this.maxBufferedAmount) {
if (this._sQ.length > 0) {
this._websocket.send(this._encode_message());
this._sQ = [];
}
// Check for full typed array support
if (('Uint8Array' in window) &&
('set' in Uint8Array.prototype)) {
bt = true;
}
// Check for full binary type support in WebSocket
// Inspired by:
// https://github.com/Modernizr/Modernizr/issues/370
// https://github.com/Modernizr/Modernizr/blob/master/feature-detects/websockets/binary.js
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 connections
}
return true;
} else {
Util.Info("Delaying send, bufferedAmount: " +
this._websocket.bufferedAmount);
return false;
}
},
// Default protocols if not specified
if (typeof(protocols) === "undefined") {
if (wsbt) {
protocols = ['binary', 'base64'];
} else {
protocols = 'base64';
}
}
send: function (arr) {
this._sQ = this._sQ.concat(arr);
return this.flush();
},
// If no binary support, make sure it was not requested
if (!wsbt) {
if (protocols === 'binary') {
throw("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");
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 {
new_protocols.push(protocols[i]);
protocols = 'base64';
}
}
if (new_protocols.length > 0) {
protocols = new_protocols;
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 {
throw("Only WebSocket binary sub-protocol was requested and not supported.");
// 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);
}
}
}
}
return protocols;
}
function open(uri, protocols) {
var ws_schema = uri.match(/^([a-z]+):\/\//)[1];
protocols = init(protocols, ws_schema);
if (test_mode) {
websocket = {};
} else {
websocket = new WebSocket(uri, protocols);
if (protocols.indexOf('binary') >= 0) {
websocket.binaryType = 'arraybuffer';
}
}
websocket.onmessage = recv_message;
websocket.onopen = function() {
Util.Debug(">> WebSock.onopen");
if (websocket.protocol) {
mode = websocket.protocol;
Util.Info("Server chose sub-protocol: " + websocket.protocol);
} else {
mode = 'base64';
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, data_mode) {
test_mode = true;
mode = data_mode;
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();
}
})();