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72f1348b | 1 | /* |
44d384b9 | 2 | * Websock: high-performance buffering wrapper |
412d9306 | 3 | * Copyright (C) 2019 The noVNC Authors |
1d728ace | 4 | * Licensed under MPL 2.0 (see LICENSE.txt) |
72f1348b | 5 | * |
44d384b9 TS |
6 | * Websock is similar to the standard WebSocket / RTCDataChannel object |
7 | * but with extra 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 | |
6d6f0db0 SR |
17 | // this has performance issues in some versions Chromium, and |
18 | // doesn't gain a tremendous amount of performance increase in Firefox | |
19 | // at the moment. It may be valuable to turn it on in the future. | |
2b5f94fa | 20 | const MAX_RQ_GROW_SIZE = 40 * 1024 * 1024; // 40 MiB |
6d6f0db0 | 21 | |
44d384b9 TS |
22 | // Constants pulled from RTCDataChannelState enum |
23 | // https://developer.mozilla.org/en-US/docs/Web/API/RTCDataChannel/readyState#RTCDataChannelState_enum | |
24 | const DataChannel = { | |
25 | CONNECTING: "connecting", | |
26 | OPEN: "open", | |
27 | CLOSING: "closing", | |
28 | CLOSED: "closed" | |
29 | }; | |
30 | ||
31 | const ReadyStates = { | |
32 | CONNECTING: [WebSocket.CONNECTING, DataChannel.CONNECTING], | |
33 | OPEN: [WebSocket.OPEN, DataChannel.OPEN], | |
34 | CLOSING: [WebSocket.CLOSING, DataChannel.CLOSING], | |
35 | CLOSED: [WebSocket.CLOSED, DataChannel.CLOSED], | |
36 | }; | |
37 | ||
38 | // Properties a raw channel must have, WebSocket and RTCDataChannel are two examples | |
39 | const rawChannelProps = [ | |
40 | "send", | |
41 | "close", | |
42 | "binaryType", | |
43 | "onerror", | |
44 | "onmessage", | |
45 | "onopen", | |
46 | "protocol", | |
47 | "readyState", | |
48 | ]; | |
49 | ||
0e4808bf JD |
50 | export default class Websock { |
51 | constructor() { | |
44d384b9 | 52 | this._websocket = null; // WebSocket or RTCDataChannel object |
0e4808bf JD |
53 | |
54 | this._rQi = 0; // Receive queue index | |
55 | this._rQlen = 0; // Next write position in the receive queue | |
56 | this._rQbufferSize = 1024 * 1024 * 4; // Receive queue buffer size (4 MiB) | |
0e4808bf JD |
57 | // called in init: this._rQ = new Uint8Array(this._rQbufferSize); |
58 | this._rQ = null; // Receive queue | |
59 | ||
60 | this._sQbufferSize = 1024 * 10; // 10 KiB | |
61 | // called in init: this._sQ = new Uint8Array(this._sQbufferSize); | |
62 | this._sQlen = 0; | |
63 | this._sQ = null; // Send queue | |
64 | ||
65 | this._eventHandlers = { | |
66 | message: () => {}, | |
67 | open: () => {}, | |
68 | close: () => {}, | |
69 | error: () => {} | |
70 | }; | |
71 | } | |
72 | ||
6d6f0db0 | 73 | // Getters and Setters |
8a189a62 | 74 | get sQ() { |
6d6f0db0 | 75 | return this._sQ; |
0e4808bf | 76 | } |
6d6f0db0 | 77 | |
8a189a62 | 78 | get rQ() { |
6d6f0db0 | 79 | return this._rQ; |
0e4808bf | 80 | } |
6d6f0db0 | 81 | |
8a189a62 | 82 | get rQi() { |
6d6f0db0 | 83 | return this._rQi; |
0e4808bf | 84 | } |
6d6f0db0 | 85 | |
8a189a62 | 86 | set rQi(val) { |
6d6f0db0 | 87 | this._rQi = val; |
0e4808bf | 88 | } |
6d6f0db0 SR |
89 | |
90 | // Receive Queue | |
8a189a62 | 91 | get rQlen() { |
6d6f0db0 | 92 | return this._rQlen - this._rQi; |
0e4808bf | 93 | } |
6d6f0db0 | 94 | |
0e4808bf | 95 | rQpeek8() { |
6d6f0db0 | 96 | return this._rQ[this._rQi]; |
0e4808bf | 97 | } |
6d6f0db0 | 98 | |
8a189a62 JD |
99 | rQskipBytes(bytes) { |
100 | this._rQi += bytes; | |
101 | } | |
102 | ||
0e4808bf | 103 | rQshift8() { |
879e33ab | 104 | return this._rQshift(1); |
0e4808bf | 105 | } |
6d6f0db0 | 106 | |
0e4808bf | 107 | rQshift16() { |
879e33ab | 108 | return this._rQshift(2); |
0e4808bf | 109 | } |
6d6f0db0 | 110 | |
0e4808bf | 111 | rQshift32() { |
879e33ab JD |
112 | return this._rQshift(4); |
113 | } | |
114 | ||
115 | // TODO(directxman12): test performance with these vs a DataView | |
116 | _rQshift(bytes) { | |
117 | let res = 0; | |
118 | for (let byte = bytes - 1; byte >= 0; byte--) { | |
119 | res += this._rQ[this._rQi++] << (byte * 8); | |
120 | } | |
121 | return res; | |
0e4808bf | 122 | } |
6d6f0db0 | 123 | |
0e4808bf | 124 | rQshiftStr(len) { |
8a189a62 | 125 | if (typeof(len) === 'undefined') { len = this.rQlen; } |
db9daa98 SM |
126 | let str = ""; |
127 | // Handle large arrays in steps to avoid long strings on the stack | |
128 | for (let i = 0; i < len; i += 4096) { | |
f90c2a6d | 129 | let part = this.rQshiftBytes(Math.min(4096, len - i)); |
d9814c06 | 130 | str += String.fromCharCode.apply(null, part); |
db9daa98 SM |
131 | } |
132 | return str; | |
0e4808bf | 133 | } |
6d6f0db0 | 134 | |
0e4808bf | 135 | rQshiftBytes(len) { |
8a189a62 | 136 | if (typeof(len) === 'undefined') { len = this.rQlen; } |
6d6f0db0 SR |
137 | this._rQi += len; |
138 | return new Uint8Array(this._rQ.buffer, this._rQi - len, len); | |
0e4808bf | 139 | } |
6d6f0db0 | 140 | |
0e4808bf | 141 | rQshiftTo(target, len) { |
8a189a62 | 142 | if (len === undefined) { len = this.rQlen; } |
6d6f0db0 SR |
143 | // TODO: make this just use set with views when using a ArrayBuffer to store the rQ |
144 | target.set(new Uint8Array(this._rQ.buffer, this._rQi, len)); | |
145 | this._rQi += len; | |
0e4808bf | 146 | } |
6d6f0db0 | 147 | |
8a189a62 JD |
148 | rQslice(start, end = this.rQlen) { |
149 | return new Uint8Array(this._rQ.buffer, this._rQi + start, end - start); | |
0e4808bf | 150 | } |
6d6f0db0 SR |
151 | |
152 | // Check to see if we must wait for 'num' bytes (default to FBU.bytes) | |
153 | // to be available in the receive queue. Return true if we need to | |
154 | // wait (and possibly print a debug message), otherwise false. | |
0e4808bf | 155 | rQwait(msg, num, goback) { |
8a189a62 | 156 | if (this.rQlen < num) { |
6d6f0db0 SR |
157 | if (goback) { |
158 | if (this._rQi < goback) { | |
159 | throw new Error("rQwait cannot backup " + goback + " bytes"); | |
2cccf753 | 160 | } |
6d6f0db0 | 161 | this._rQi -= goback; |
2cccf753 | 162 | } |
6d6f0db0 SR |
163 | return true; // true means need more data |
164 | } | |
165 | return false; | |
0e4808bf | 166 | } |
72f1348b | 167 | |
6d6f0db0 | 168 | // Send Queue |
72f1348b | 169 | |
0e4808bf | 170 | flush() { |
44d384b9 | 171 | if (this._sQlen > 0 && ReadyStates.OPEN.indexOf(this._websocket.readyState) >= 0) { |
ea858bfa | 172 | this._websocket.send(this._encodeMessage()); |
6d6f0db0 SR |
173 | this._sQlen = 0; |
174 | } | |
0e4808bf | 175 | } |
6d6f0db0 | 176 | |
0e4808bf | 177 | send(arr) { |
6d6f0db0 SR |
178 | this._sQ.set(arr, this._sQlen); |
179 | this._sQlen += arr.length; | |
180 | this.flush(); | |
0e4808bf | 181 | } |
6d6f0db0 | 182 | |
ea858bfa | 183 | sendString(str) { |
651c23ec | 184 | this.send(str.split('').map(chr => chr.charCodeAt(0))); |
0e4808bf | 185 | } |
6d6f0db0 SR |
186 | |
187 | // Event Handlers | |
0e4808bf | 188 | off(evt) { |
651c23ec | 189 | this._eventHandlers[evt] = () => {}; |
0e4808bf | 190 | } |
6d6f0db0 | 191 | |
0e4808bf | 192 | on(evt, handler) { |
6d6f0db0 | 193 | this._eventHandlers[evt] = handler; |
0e4808bf | 194 | } |
6d6f0db0 | 195 | |
ea858bfa | 196 | _allocateBuffers() { |
6d6f0db0 SR |
197 | this._rQ = new Uint8Array(this._rQbufferSize); |
198 | this._sQ = new Uint8Array(this._sQbufferSize); | |
0e4808bf | 199 | } |
6d6f0db0 | 200 | |
0e4808bf | 201 | init() { |
ea858bfa | 202 | this._allocateBuffers(); |
6d6f0db0 SR |
203 | this._rQi = 0; |
204 | this._websocket = null; | |
0e4808bf | 205 | } |
6d6f0db0 | 206 | |
0e4808bf | 207 | open(uri, protocols) { |
44d384b9 TS |
208 | this.attach(new WebSocket(uri, protocols)); |
209 | } | |
210 | ||
211 | attach(rawChannel) { | |
6d6f0db0 SR |
212 | this.init(); |
213 | ||
44d384b9 TS |
214 | // Must get object and class methods to be compatible with the tests. |
215 | const channelProps = [...Object.keys(rawChannel), ...Object.getOwnPropertyNames(Object.getPrototypeOf(rawChannel))]; | |
216 | for (let i = 0; i < rawChannelProps.length; i++) { | |
217 | const prop = rawChannelProps[i]; | |
218 | if (channelProps.indexOf(prop) < 0) { | |
219 | throw new Error('Raw channel missing property: ' + prop); | |
220 | } | |
221 | } | |
6d6f0db0 | 222 | |
44d384b9 TS |
223 | this._websocket = rawChannel; |
224 | this._websocket.binaryType = "arraybuffer"; | |
ea858bfa | 225 | this._websocket.onmessage = this._recvMessage.bind(this); |
44d384b9 TS |
226 | |
227 | const onOpen = () => { | |
6d6f0db0 SR |
228 | Log.Debug('>> WebSock.onopen'); |
229 | if (this._websocket.protocol) { | |
230 | Log.Info("Server choose sub-protocol: " + this._websocket.protocol); | |
2cccf753 | 231 | } |
2cccf753 | 232 | |
6d6f0db0 SR |
233 | this._eventHandlers.open(); |
234 | Log.Debug("<< WebSock.onopen"); | |
651c23ec | 235 | }; |
44d384b9 TS |
236 | |
237 | // If the readyState cannot be found this defaults to assuming it's not open. | |
238 | const isOpen = ReadyStates.OPEN.indexOf(this._websocket.readyState) >= 0; | |
239 | if (isOpen) { | |
240 | onOpen(); | |
241 | } else { | |
242 | this._websocket.onopen = onOpen; | |
243 | } | |
244 | ||
651c23ec | 245 | this._websocket.onclose = (e) => { |
6d6f0db0 SR |
246 | Log.Debug(">> WebSock.onclose"); |
247 | this._eventHandlers.close(e); | |
248 | Log.Debug("<< WebSock.onclose"); | |
651c23ec | 249 | }; |
44d384b9 | 250 | |
651c23ec | 251 | this._websocket.onerror = (e) => { |
6d6f0db0 SR |
252 | Log.Debug(">> WebSock.onerror: " + e); |
253 | this._eventHandlers.error(e); | |
254 | Log.Debug("<< WebSock.onerror: " + e); | |
651c23ec | 255 | }; |
0e4808bf | 256 | } |
6d6f0db0 | 257 | |
0e4808bf | 258 | close() { |
6d6f0db0 | 259 | if (this._websocket) { |
44d384b9 TS |
260 | if (ReadyStates.CONNECTING.indexOf(this._websocket.readyState) >= 0 || |
261 | ReadyStates.OPEN.indexOf(this._websocket.readyState) >= 0) { | |
6d6f0db0 SR |
262 | Log.Info("Closing WebSocket connection"); |
263 | this._websocket.close(); | |
fcff386b | 264 | } |
6d6f0db0 | 265 | |
651c23ec | 266 | this._websocket.onmessage = () => {}; |
6d6f0db0 | 267 | } |
0e4808bf | 268 | } |
6d6f0db0 SR |
269 | |
270 | // private methods | |
ea858bfa | 271 | _encodeMessage() { |
6d6f0db0 SR |
272 | // Put in a binary arraybuffer |
273 | // according to the spec, you can send ArrayBufferViews with the send method | |
274 | return new Uint8Array(this._sQ.buffer, 0, this._sQlen); | |
0e4808bf | 275 | } |
6d6f0db0 | 276 | |
e8614e20 SM |
277 | // We want to move all the unread data to the start of the queue, |
278 | // e.g. compacting. | |
279 | // The function also expands the receive que if needed, and for | |
280 | // performance reasons we combine these two actions to avoid | |
281 | // unneccessary copying. | |
ea858bfa | 282 | _expandCompactRQ(minFit) { |
7d755d10 JAD |
283 | // if we're using less than 1/8th of the buffer even with the incoming bytes, compact in place |
284 | // instead of resizing | |
ea858bfa SM |
285 | const requiredBufferSize = (this._rQlen - this._rQi + minFit) * 8; |
286 | const resizeNeeded = this._rQbufferSize < requiredBufferSize; | |
7d755d10 | 287 | |
6d6f0db0 | 288 | if (resizeNeeded) { |
7d755d10 JAD |
289 | // Make sure we always *at least* double the buffer size, and have at least space for 8x |
290 | // the current amount of data | |
ea858bfa | 291 | this._rQbufferSize = Math.max(this._rQbufferSize * 2, requiredBufferSize); |
6d6f0db0 | 292 | } |
40037b6a | 293 | |
6d6f0db0 SR |
294 | // we don't want to grow unboundedly |
295 | if (this._rQbufferSize > MAX_RQ_GROW_SIZE) { | |
296 | this._rQbufferSize = MAX_RQ_GROW_SIZE; | |
ea858bfa | 297 | if (this._rQbufferSize - this.rQlen < minFit) { |
8727f598 | 298 | throw new Error("Receive Queue buffer exceeded " + MAX_RQ_GROW_SIZE + " bytes, and the new message could not fit"); |
40037b6a | 299 | } |
6d6f0db0 | 300 | } |
40037b6a | 301 | |
6d6f0db0 | 302 | if (resizeNeeded) { |
ea858bfa | 303 | const oldRQbuffer = this._rQ.buffer; |
6d6f0db0 | 304 | this._rQ = new Uint8Array(this._rQbufferSize); |
ea858bfa | 305 | this._rQ.set(new Uint8Array(oldRQbuffer, this._rQi, this._rQlen - this._rQi)); |
6d6f0db0 | 306 | } else { |
5b5b7474 | 307 | this._rQ.copyWithin(0, this._rQi, this._rQlen); |
6d6f0db0 | 308 | } |
40037b6a | 309 | |
6d6f0db0 SR |
310 | this._rQlen = this._rQlen - this._rQi; |
311 | this._rQi = 0; | |
0e4808bf | 312 | } |
40037b6a | 313 | |
e8614e20 | 314 | // push arraybuffer values onto the end of the receive que |
ea858bfa | 315 | _DecodeMessage(data) { |
2b5f94fa | 316 | const u8 = new Uint8Array(data); |
6d6f0db0 | 317 | if (u8.length > this._rQbufferSize - this._rQlen) { |
ea858bfa | 318 | this._expandCompactRQ(u8.length); |
6d6f0db0 SR |
319 | } |
320 | this._rQ.set(u8, this._rQlen); | |
321 | this._rQlen += u8.length; | |
0e4808bf | 322 | } |
fcff386b | 323 | |
ea858bfa SM |
324 | _recvMessage(e) { |
325 | this._DecodeMessage(e.data); | |
8a189a62 | 326 | if (this.rQlen > 0) { |
1678bf86 | 327 | this._eventHandlers.message(); |
1678bf86 | 328 | if (this._rQlen == this._rQi) { |
e8614e20 SM |
329 | // All data has now been processed, this means we |
330 | // can reset the receive queue. | |
1678bf86 PO |
331 | this._rQlen = 0; |
332 | this._rQi = 0; | |
2cccf753 | 333 | } |
1678bf86 PO |
334 | } else { |
335 | Log.Debug("Ignoring empty message"); | |
72f1348b | 336 | } |
6d6f0db0 | 337 | } |
0e4808bf | 338 | } |