forked from pladaria/reconnecting-websocket
/
reconnecting-websocket.ts
436 lines (381 loc) · 12.5 KB
/
reconnecting-websocket.ts
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
/*!
* Reconnecting WebSocket
* by Pedro Ladaria <pedro.ladaria@gmail.com>
* https://github.com/pladaria/reconnecting-websocket
* License MIT
*/
import {CloseEvent, ErrorEvent, Event, EventListener, WebSocketEventMap} from './events';
import RNTimer from "react-native-background-timer";
const _setTimeout = RNTimer ? (callback: () => void, time: number) => RNTimer.setTimeout(callback, time) : setTimeout;
const _clearTimeout = RNTimer ? (time: number) => RNTimer.clearTimeout(time) : clearTimeout;
const getGlobalWebSocket = (): WebSocket | undefined => {
if (typeof WebSocket !== 'undefined') {
// @ts-ignore
return WebSocket;
}
};
/**
* Returns true if given argument looks like a WebSocket class
*/
const isWebSocket = (w: any) => typeof w === 'function' && w.CLOSING === 2;
export type Options = {
WebSocket?: any;
maxReconnectionDelay?: number;
minReconnectionDelay?: number;
reconnectionDelayGrowFactor?: number;
minUptime?: number;
connectionTimeout?: number;
maxRetries?: number;
debug?: boolean;
};
const DEFAULT = {
maxReconnectionDelay: 10000,
minReconnectionDelay: 1000 + Math.random() * 4000,
minUptime: 5000,
reconnectionDelayGrowFactor: 1.3,
connectionTimeout: 4000,
maxRetries: Infinity,
debug: false,
};
export type UrlProvider = string | (() => string) | (() => Promise<string>);
export type ListenersMap = {
error: Array<((event: ErrorEvent) => void)>;
message: Array<((event: MessageEvent) => void)>;
open: Array<((event: Event) => void)>;
close: Array<((event: CloseEvent) => void)>;
};
export default class ReconnectingWebSocket {
private _ws?: WebSocket;
private _listeners: ListenersMap = {
error: [],
message: [],
open: [],
close: [],
};
private _retryCount = -1;
private _uptimeTimeout: any;
private _connectTimeout: any;
private _shouldReconnect = true;
private _connectLock = false;
private _binaryType = 'blob';
private readonly _url: UrlProvider;
private readonly _protocols?: string | string[];
private readonly _options: Options;
private readonly eventToHandler = new Map<keyof WebSocketEventMap, any>([
['open', this._handleOpen.bind(this)],
['close', this._handleClose.bind(this)],
['error', this._handleError.bind(this)],
['message', this._handleMessage.bind(this)],
]);
constructor(url: UrlProvider, protocols?: string | string[], options: Options = {}) {
this._url = url;
this._protocols = protocols;
this._options = options;
this._connect();
}
static get CONNECTING() {
return 0;
}
static get OPEN() {
return 1;
}
static get CLOSING() {
return 2;
}
static get CLOSED() {
return 3;
}
get CONNECTING() {
return ReconnectingWebSocket.CONNECTING;
}
get OPEN() {
return ReconnectingWebSocket.OPEN;
}
get CLOSING() {
return ReconnectingWebSocket.CLOSING;
}
get CLOSED() {
return ReconnectingWebSocket.CLOSED;
}
get binaryType(): string {
return this._ws ? this._ws.binaryType : this._binaryType;
}
set binaryType(value: string) {
this._binaryType = value;
if (this._ws) {
// @ts-ignore
this._ws.binaryType = value;
}
}
/**
* Returns the number or connection retries
*/
get retryCount(): number {
return Math.max(this._retryCount, 0);
}
/**
* The number of bytes of data that have been queued using calls to send() but not yet
* transmitted to the network. This value resets to zero once all queued data has been sent.
* This value does not reset to zero when the connection is closed; if you keep calling send(),
* this will continue to climb. Read only
*/
get bufferedAmount(): number {
return this._ws ? this._ws.bufferedAmount : 0;
}
/**
* The extensions selected by the server. This is currently only the empty string or a list of
* extensions as negotiated by the connection
*/
get extensions(): string {
return this._ws ? this._ws.extensions : '';
}
/**
* A string indicating the name of the sub-protocol the server selected;
* this will be one of the strings specified in the protocols parameter when creating the
* WebSocket object
*/
get protocol(): string {
return this._ws ? this._ws.protocol : '';
}
/**
* The current state of the connection; this is one of the Ready state constants
*/
get readyState(): number {
return this._ws ? this._ws.readyState : ReconnectingWebSocket.CONNECTING;
}
/**
* The URL as resolved by the constructor
*/
get url(): string {
return this._ws ? this._ws.url : '';
}
/**
* An event listener to be called when the WebSocket connection's readyState changes to CLOSED
*/
public onclose?: (event: CloseEvent) => void = undefined;
/**
* An event listener to be called when an error occurs
*/
public onerror?: (event: Event) => void = undefined;
/**
* An event listener to be called when a message is received from the server
*/
public onmessage?: (event: MessageEvent) => void = undefined;
/**
* An event listener to be called when the WebSocket connection's readyState changes to OPEN;
* this indicates that the connection is ready to send and receive data
*/
public onopen?: (event: Event) => void = undefined;
/**
* Closes the WebSocket connection or connection attempt, if any. If the connection is already
* CLOSED, this method does nothing
*/
public close(code?: number, reason?: string) {
this._shouldReconnect = false;
if (!this._ws || this._ws.readyState === this.CLOSED) {
return;
}
this._ws.close(code, reason);
}
/**
* Closes the WebSocket connection or connection attempt and connects again.
* Resets retry counter;
*/
public reconnect(code?: number, reason?: string) {
this._shouldReconnect = true;
this._retryCount = -1;
if (!this._ws || this._ws.readyState === this.CLOSED) {
this._connect();
}
this._disconnect(code, reason);
this._connect();
}
/**
* Enqueues the specified data to be transmitted to the server over the WebSocket connection
*/
public send(data: string | ArrayBuffer | Blob | ArrayBufferView) {
if (this._ws) {
this._ws.send(data);
}
}
/**
* Register an event handler of a specific event type
*/
public addEventListener<K extends keyof WebSocketEventMap>(
type: K,
listener: ((event: WebSocketEventMap[K]) => void),
): void {
if (this._listeners[type]) {
// @ts-ignore
this._listeners[type].push(listener);
}
}
/**
* Removes an event listener
*/
public removeEventListener<K extends keyof WebSocketEventMap>(
type: K,
listener: ((event: WebSocketEventMap[K]) => void),
): void {
if (this._listeners[type]) {
// @ts-ignore
this._listeners[type] = this._listeners[type].filter(l => l !== listener);
}
}
private _debug(...params: any[]) {
if (this._options.debug) {
// tslint:disable-next-line
console.log('RWS>', ...params);
}
}
private _getNextDelay() {
let delay = 0;
if (this._retryCount > 0) {
const {
reconnectionDelayGrowFactor = DEFAULT.reconnectionDelayGrowFactor,
minReconnectionDelay = DEFAULT.minReconnectionDelay,
maxReconnectionDelay = DEFAULT.maxReconnectionDelay,
} = this._options;
delay =
minReconnectionDelay + Math.pow(this._retryCount - 1, reconnectionDelayGrowFactor);
if (delay > maxReconnectionDelay) {
delay = maxReconnectionDelay;
}
}
this._debug('next delay', delay);
return delay;
}
private _wait(): Promise<void> {
return new Promise(resolve => {
_setTimeout(resolve, this._getNextDelay());
});
}
/**
* @return Promise<string>
*/
private _getNextUrl(urlProvider: UrlProvider): Promise<string> {
if (typeof urlProvider === 'string') {
return Promise.resolve(urlProvider);
}
if (typeof urlProvider === 'function') {
const url = urlProvider();
if (typeof url === 'string') {
return Promise.resolve(url);
}
if (url.then) {
return url;
}
}
throw Error('Invalid URL');
}
private _connect() {
if (this._connectLock) {
return;
}
this._connectLock = true;
const {
maxRetries = DEFAULT.maxRetries,
connectionTimeout = DEFAULT.connectionTimeout,
WebSocket = getGlobalWebSocket(),
} = this._options;
if (this._retryCount >= maxRetries) {
this._debug('max retries reached', this._retryCount, '>=', maxRetries);
return;
}
this._retryCount++;
this._debug('connect', this._retryCount);
this._removeListeners();
if (!isWebSocket(WebSocket)) {
throw Error('No valid WebSocket class provided');
}
this._wait()
.then(() => this._getNextUrl(this._url))
.then(url => {
this._debug('connect', {url, protocols: this._protocols});
this._ws = new WebSocket(url, this._protocols);
// @ts-ignore
this._ws!.binaryType = this._binaryType;
this._connectLock = false;
this._addListeners();
this._connectTimeout = _setTimeout(() => this._handleTimeout(), connectionTimeout);
});
}
private _handleTimeout() {
this._debug('timeout event');
this._handleError(new ErrorEvent(Error('TIMEOUT'), this));
}
private _disconnect(code?: number, reason?: string) {
_clearTimeout(this._connectTimeout);
if (!this._ws) {
return;
}
this._removeListeners();
try {
this._ws.close(code, reason);
this._handleClose(new CloseEvent(code, reason, this));
} catch (error) {
// ignore
}
}
private _acceptOpen() {
this._retryCount = 0;
}
private _handleOpen(event: Event) {
this._debug('open event');
const {minUptime = DEFAULT.minUptime} = this._options;
_clearTimeout(this._connectTimeout);
this._uptimeTimeout = _setTimeout(() => this._acceptOpen(), minUptime);
this._debug('assign binary type');
// @ts-ignore
this._ws!.binaryType = this._binaryType;
if (this.onopen) {
this.onopen(event);
}
this._listeners.open.forEach(listener => listener(event));
}
private _handleMessage(event: MessageEvent) {
this._debug('message event');
if (this.onmessage) {
this.onmessage(event);
}
this._listeners.message.forEach(listener => listener(event));
}
private _handleError(event: ErrorEvent) {
this._debug('error event', event.message);
this._disconnect(undefined, event.message === 'TIMEOUT' ? 'timeout' : undefined);
if (this.onerror) {
this.onerror(event);
}
this._debug('exec error listeners');
this._listeners.error.forEach(listener => listener(event));
this._connect();
}
private _handleClose(event: CloseEvent) {
this._debug('close event');
if (this.onclose) {
this.onclose(event);
}
this._listeners.close.forEach(listener => listener(event));
}
/**
* Remove event listeners to WebSocket instance
*/
private _removeListeners() {
if (!this._ws) {
return;
}
this._debug('removeListeners');
for (const [type, handler] of this.eventToHandler) {
this._ws.removeEventListener(type, handler);
}
}
/**
* Assign event listeners to WebSocket instance
*/
private _addListeners() {
this._debug('addListeners');
for (const [type, handler] of this.eventToHandler) {
this._ws!.addEventListener(type, handler);
}
}
}