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72f1348b JM |
1 | /* |
2 | * Websock: high-performance binary WebSockets | |
d58f8b51 | 3 | * Copyright (C) 2012 Joel Martin |
1d728ace | 4 | * Licensed under MPL 2.0 (see LICENSE.txt) |
72f1348b | 5 | * |
d2467189 PO |
6 | * Websock is similar to the standard WebSocket object but with extra |
7 | * buffer handling. | |
72f1348b JM |
8 | * |
9 | * Websock has built-in receive queue buffering; the message event | |
10 | * does not contain actual data but is simply a notification that | |
11 | * there is new data available. Several rQ* methods are available to | |
12 | * read binary data off of the receive queue. | |
13 | */ | |
14 | ||
6d6f0db0 | 15 | import * as Log from './util/logging.js'; |
ae510306 | 16 | |
3ae0bb09 | 17 | export default function Websock() { |
2cccf753 SR |
18 | "use strict"; |
19 | ||
20 | this._websocket = null; // WebSocket object | |
38781d93 | 21 | |
2cccf753 | 22 | this._rQi = 0; // Receive queue index |
38781d93 SR |
23 | this._rQlen = 0; // Next write position in the receive queue |
24 | this._rQbufferSize = 1024 * 1024 * 4; // Receive queue buffer size (4 MiB) | |
25 | this._rQmax = this._rQbufferSize / 8; | |
38781d93 SR |
26 | // called in init: this._rQ = new Uint8Array(this._rQbufferSize); |
27 | this._rQ = null; // Receive queue | |
2cccf753 | 28 | |
9ff86fb7 SR |
29 | this._sQbufferSize = 1024 * 10; // 10 KiB |
30 | // called in init: this._sQ = new Uint8Array(this._sQbufferSize); | |
31 | this._sQlen = 0; | |
32 | this._sQ = null; // Send queue | |
33 | ||
2cccf753 SR |
34 | this._eventHandlers = { |
35 | 'message': function () {}, | |
36 | 'open': function () {}, | |
37 | 'close': function () {}, | |
38 | 'error': function () {} | |
39 | }; | |
8727f598 | 40 | } |
72f1348b | 41 | |
6d6f0db0 SR |
42 | // this has performance issues in some versions Chromium, and |
43 | // doesn't gain a tremendous amount of performance increase in Firefox | |
44 | // at the moment. It may be valuable to turn it on in the future. | |
45 | var ENABLE_COPYWITHIN = false; | |
46 | ||
47 | var MAX_RQ_GROW_SIZE = 40 * 1024 * 1024; // 40 MiB | |
48 | ||
49 | var typedArrayToString = (function () { | |
50 | // This is only for PhantomJS, which doesn't like apply-ing | |
51 | // with Typed Arrays | |
52 | try { | |
53 | var arr = new Uint8Array([1, 2, 3]); | |
54 | String.fromCharCode.apply(null, arr); | |
55 | return function (a) { return String.fromCharCode.apply(null, a); }; | |
56 | } catch (ex) { | |
57 | return function (a) { | |
58 | return String.fromCharCode.apply( | |
59 | null, Array.prototype.slice.call(a)); | |
60 | }; | |
61 | } | |
62 | })(); | |
40037b6a | 63 | |
6d6f0db0 SR |
64 | Websock.prototype = { |
65 | // Getters and Setters | |
66 | get_sQ: function () { | |
67 | return this._sQ; | |
68 | }, | |
69 | ||
70 | get_rQ: function () { | |
71 | return this._rQ; | |
72 | }, | |
73 | ||
74 | get_rQi: function () { | |
75 | return this._rQi; | |
76 | }, | |
77 | ||
78 | set_rQi: function (val) { | |
79 | this._rQi = val; | |
80 | }, | |
81 | ||
82 | // Receive Queue | |
83 | rQlen: function () { | |
84 | return this._rQlen - this._rQi; | |
85 | }, | |
86 | ||
87 | rQpeek8: function () { | |
88 | return this._rQ[this._rQi]; | |
89 | }, | |
90 | ||
91 | rQshift8: function () { | |
92 | return this._rQ[this._rQi++]; | |
93 | }, | |
94 | ||
95 | rQskip8: function () { | |
96 | this._rQi++; | |
97 | }, | |
98 | ||
99 | rQskipBytes: function (num) { | |
100 | this._rQi += num; | |
101 | }, | |
102 | ||
103 | // TODO(directxman12): test performance with these vs a DataView | |
104 | rQshift16: function () { | |
105 | return (this._rQ[this._rQi++] << 8) + | |
106 | this._rQ[this._rQi++]; | |
107 | }, | |
108 | ||
109 | rQshift32: function () { | |
110 | return (this._rQ[this._rQi++] << 24) + | |
111 | (this._rQ[this._rQi++] << 16) + | |
112 | (this._rQ[this._rQi++] << 8) + | |
113 | this._rQ[this._rQi++]; | |
114 | }, | |
115 | ||
116 | rQshiftStr: function (len) { | |
117 | if (typeof(len) === 'undefined') { len = this.rQlen(); } | |
118 | var arr = new Uint8Array(this._rQ.buffer, this._rQi, len); | |
119 | this._rQi += len; | |
120 | return typedArrayToString(arr); | |
121 | }, | |
122 | ||
123 | rQshiftBytes: function (len) { | |
124 | if (typeof(len) === 'undefined') { len = this.rQlen(); } | |
125 | this._rQi += len; | |
126 | return new Uint8Array(this._rQ.buffer, this._rQi - len, len); | |
127 | }, | |
128 | ||
129 | rQshiftTo: function (target, len) { | |
130 | if (len === undefined) { len = this.rQlen(); } | |
131 | // TODO: make this just use set with views when using a ArrayBuffer to store the rQ | |
132 | target.set(new Uint8Array(this._rQ.buffer, this._rQi, len)); | |
133 | this._rQi += len; | |
134 | }, | |
135 | ||
136 | rQwhole: function () { | |
137 | return new Uint8Array(this._rQ.buffer, 0, this._rQlen); | |
138 | }, | |
139 | ||
140 | rQslice: function (start, end) { | |
141 | if (end) { | |
142 | return new Uint8Array(this._rQ.buffer, this._rQi + start, end - start); | |
143 | } else { | |
144 | return new Uint8Array(this._rQ.buffer, this._rQi + start, this._rQlen - this._rQi - start); | |
38781d93 | 145 | } |
6d6f0db0 SR |
146 | }, |
147 | ||
148 | // Check to see if we must wait for 'num' bytes (default to FBU.bytes) | |
149 | // to be available in the receive queue. Return true if we need to | |
150 | // wait (and possibly print a debug message), otherwise false. | |
151 | rQwait: function (msg, num, goback) { | |
152 | var rQlen = this._rQlen - this._rQi; // Skip rQlen() function call | |
153 | if (rQlen < num) { | |
154 | if (goback) { | |
155 | if (this._rQi < goback) { | |
156 | throw new Error("rQwait cannot backup " + goback + " bytes"); | |
2cccf753 | 157 | } |
6d6f0db0 | 158 | this._rQi -= goback; |
2cccf753 | 159 | } |
6d6f0db0 SR |
160 | return true; // true means need more data |
161 | } | |
162 | return false; | |
163 | }, | |
72f1348b | 164 | |
6d6f0db0 | 165 | // Send Queue |
72f1348b | 166 | |
6d6f0db0 | 167 | flush: function () { |
6d6f0db0 SR |
168 | if (this._sQlen > 0 && this._websocket.readyState === WebSocket.OPEN) { |
169 | this._websocket.send(this._encode_message()); | |
170 | this._sQlen = 0; | |
171 | } | |
172 | }, | |
173 | ||
174 | send: function (arr) { | |
175 | this._sQ.set(arr, this._sQlen); | |
176 | this._sQlen += arr.length; | |
177 | this.flush(); | |
178 | }, | |
179 | ||
180 | send_string: function (str) { | |
181 | this.send(str.split('').map(function (chr) { | |
182 | return chr.charCodeAt(0); | |
183 | })); | |
184 | }, | |
185 | ||
186 | // Event Handlers | |
187 | off: function (evt) { | |
188 | this._eventHandlers[evt] = function () {}; | |
189 | }, | |
190 | ||
191 | on: function (evt, handler) { | |
192 | this._eventHandlers[evt] = handler; | |
193 | }, | |
194 | ||
195 | _allocate_buffers: function () { | |
196 | this._rQ = new Uint8Array(this._rQbufferSize); | |
197 | this._sQ = new Uint8Array(this._sQbufferSize); | |
198 | }, | |
199 | ||
200 | init: function () { | |
201 | this._allocate_buffers(); | |
202 | this._rQi = 0; | |
203 | this._websocket = null; | |
204 | }, | |
205 | ||
206 | open: function (uri, protocols) { | |
6d6f0db0 SR |
207 | this.init(); |
208 | ||
209 | this._websocket = new WebSocket(uri, protocols); | |
210 | this._websocket.binaryType = 'arraybuffer'; | |
211 | ||
212 | this._websocket.onmessage = this._recv_message.bind(this); | |
213 | this._websocket.onopen = (function () { | |
214 | Log.Debug('>> WebSock.onopen'); | |
215 | if (this._websocket.protocol) { | |
216 | Log.Info("Server choose sub-protocol: " + this._websocket.protocol); | |
2cccf753 | 217 | } |
2cccf753 | 218 | |
6d6f0db0 SR |
219 | this._eventHandlers.open(); |
220 | Log.Debug("<< WebSock.onopen"); | |
221 | }).bind(this); | |
222 | this._websocket.onclose = (function (e) { | |
223 | Log.Debug(">> WebSock.onclose"); | |
224 | this._eventHandlers.close(e); | |
225 | Log.Debug("<< WebSock.onclose"); | |
226 | }).bind(this); | |
227 | this._websocket.onerror = (function (e) { | |
228 | Log.Debug(">> WebSock.onerror: " + e); | |
229 | this._eventHandlers.error(e); | |
230 | Log.Debug("<< WebSock.onerror: " + e); | |
231 | }).bind(this); | |
232 | }, | |
233 | ||
234 | close: function () { | |
235 | if (this._websocket) { | |
236 | if ((this._websocket.readyState === WebSocket.OPEN) || | |
237 | (this._websocket.readyState === WebSocket.CONNECTING)) { | |
238 | Log.Info("Closing WebSocket connection"); | |
239 | this._websocket.close(); | |
fcff386b | 240 | } |
6d6f0db0 SR |
241 | |
242 | this._websocket.onmessage = function (e) { return; }; | |
243 | } | |
244 | }, | |
245 | ||
246 | // private methods | |
247 | _encode_message: function () { | |
248 | // Put in a binary arraybuffer | |
249 | // according to the spec, you can send ArrayBufferViews with the send method | |
250 | return new Uint8Array(this._sQ.buffer, 0, this._sQlen); | |
251 | }, | |
252 | ||
253 | _expand_compact_rQ: function (min_fit) { | |
254 | var resizeNeeded = min_fit || this._rQlen - this._rQi > this._rQbufferSize / 2; | |
255 | if (resizeNeeded) { | |
256 | if (!min_fit) { | |
257 | // just double the size if we need to do compaction | |
258 | this._rQbufferSize *= 2; | |
259 | } else { | |
260 | // otherwise, make sure we satisy rQlen - rQi + min_fit < rQbufferSize / 8 | |
261 | this._rQbufferSize = (this._rQlen - this._rQi + min_fit) * 8; | |
40037b6a | 262 | } |
6d6f0db0 | 263 | } |
40037b6a | 264 | |
6d6f0db0 SR |
265 | // we don't want to grow unboundedly |
266 | if (this._rQbufferSize > MAX_RQ_GROW_SIZE) { | |
267 | this._rQbufferSize = MAX_RQ_GROW_SIZE; | |
268 | if (this._rQbufferSize - this._rQlen - this._rQi < min_fit) { | |
8727f598 | 269 | throw new Error("Receive Queue buffer exceeded " + MAX_RQ_GROW_SIZE + " bytes, and the new message could not fit"); |
40037b6a | 270 | } |
6d6f0db0 | 271 | } |
40037b6a | 272 | |
6d6f0db0 SR |
273 | if (resizeNeeded) { |
274 | var old_rQbuffer = this._rQ.buffer; | |
275 | this._rQmax = this._rQbufferSize / 8; | |
276 | this._rQ = new Uint8Array(this._rQbufferSize); | |
277 | this._rQ.set(new Uint8Array(old_rQbuffer, this._rQi)); | |
278 | } else { | |
279 | if (ENABLE_COPYWITHIN) { | |
280 | this._rQ.copyWithin(0, this._rQi); | |
40037b6a | 281 | } else { |
6d6f0db0 | 282 | this._rQ.set(new Uint8Array(this._rQ.buffer, this._rQi)); |
40037b6a | 283 | } |
6d6f0db0 | 284 | } |
40037b6a | 285 | |
6d6f0db0 SR |
286 | this._rQlen = this._rQlen - this._rQi; |
287 | this._rQi = 0; | |
288 | }, | |
40037b6a | 289 | |
6d6f0db0 SR |
290 | _decode_message: function (data) { |
291 | // push arraybuffer values onto the end | |
292 | var u8 = new Uint8Array(data); | |
293 | if (u8.length > this._rQbufferSize - this._rQlen) { | |
294 | this._expand_compact_rQ(u8.length); | |
295 | } | |
296 | this._rQ.set(u8, this._rQlen); | |
297 | this._rQlen += u8.length; | |
298 | }, | |
fcff386b | 299 | |
6d6f0db0 | 300 | _recv_message: function (e) { |
1678bf86 PO |
301 | this._decode_message(e.data); |
302 | if (this.rQlen() > 0) { | |
303 | this._eventHandlers.message(); | |
304 | // Compact the receive queue | |
305 | if (this._rQlen == this._rQi) { | |
306 | this._rQlen = 0; | |
307 | this._rQi = 0; | |
308 | } else if (this._rQlen > this._rQmax) { | |
309 | this._expand_compact_rQ(); | |
2cccf753 | 310 | } |
1678bf86 PO |
311 | } else { |
312 | Log.Debug("Ignoring empty message"); | |
72f1348b | 313 | } |
6d6f0db0 SR |
314 | } |
315 | }; |