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Class: UWSWebSocketShim

Defined in: service-core/src/http/uWS/WebSocket.ts:42

Wraps a uWS WebSocket handle and exposes an EventEmitter-based API compatible with what route handlers (e.g. AdminRoute) expect.

uWS WebSockets fire events via behavior callbacks on the route, not on the socket object itself. This shim bridges that gap by:

  • Forwarding message / close events from the route behavior to this emitter.
  • Exposing send(data, cb?) and close(code?, reason?) that delegate to uWS.

The Router's ws() implementation stores the shim in ws.getUserData() so that behavior callbacks can call shim.emit(...).

Extends​

  • EventEmitter

Implements​

Constructors​

Constructor​

new UWSWebSocketShim(ws): UWSWebSocketShim

Defined in: service-core/src/http/uWS/WebSocket.ts:46

Parameters​

ws​

WebSocket<any>

Returns​

UWSWebSocketShim

Overrides​

EventEmitter.constructor

Properties​

readyState​

readyState: number = 1

Defined in: service-core/src/http/uWS/WebSocket.ts:44

Implementation of​

IWebSocketShim.readyState

Methods​

[captureRejectionSymbol]()?​

optional [captureRejectionSymbol](error, event, ...args): void

Defined in: service-core/node_modules/@types/node/events.d.ts:87

The Symbol.for('nodejs.rejection') method is called in case a promise rejection happens when emitting an event and captureRejections is enabled on the emitter. It is possible to use events.captureRejectionSymbol in place of Symbol.for('nodejs.rejection').

import { EventEmitter, captureRejectionSymbol } from 'node:events';

class MyClass extends EventEmitter {
  constructor() {
    super({ captureRejections: true });
  }

  [captureRejectionSymbol](err, event, ...args) {
    console.log('rejection happened for', event, 'with', err, ...args);
    this.destroy(err);
  }

  destroy(err) {
    // Tear the resource down here.
  }
}

Parameters​

error​

Error

event​

string | symbol

args​

...any[]

Returns​

void

Since​

v13.4.0, v12.16.0

Implementation of​

IWebSocketShim.[captureRejectionSymbol]

Inherited from​

EventEmitter.[captureRejectionSymbol]

addListener()​

addListener<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:92

Alias for emitter.on(eventName, listener).

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

listener​

(...args) => void

Returns​

this

Since​

v0.1.26

Implementation of​

IWebSocketShim.addListener

Inherited from​

EventEmitter.addListener

close()​

close(code?, reason?): void

Defined in: service-core/src/http/uWS/WebSocket.ts:70

Closes the WebSocket connection with an optional code and reason.

Parameters​

code?​

number

reason?​

string

Returns​

void

Implementation of​

IWebSocketShim.close

emit()​

emit<E>(eventName, ...args): boolean

Defined in: service-core/node_modules/@types/node/events.d.ts:134

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

args​

...any[]

Returns​

boolean

Since​

v0.1.26

Implementation of​

IWebSocketShim.emit

Inherited from​

EventEmitter.emit

eventNames()​

eventNames(): (string | symbol)[]

Defined in: service-core/node_modules/@types/node/events.d.ts:154

Returns an array listing the events for which the emitter has registered listeners.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

Returns​

(string | symbol)[]

Since​

v6.0.0

Implementation of​

IWebSocketShim.eventNames

Inherited from​

EventEmitter.eventNames

getMaxListeners()​

getMaxListeners(): number

Defined in: service-core/node_modules/@types/node/events.d.ts:161

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to events.defaultMaxListeners.

Returns​

number

Since​

v1.0.0

Implementation of​

IWebSocketShim.getMaxListeners

Inherited from​

EventEmitter.getMaxListeners

listenerCount()​

listenerCount<E>(eventName, listener?): number

Defined in: service-core/node_modules/@types/node/events.d.ts:170

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

The name of the event being listened for

listener?​

(...args) => void

The event handler function

Returns​

number

Since​

v3.2.0

Implementation of​

IWebSocketShim.listenerCount

Inherited from​

EventEmitter.listenerCount

listeners()​

listeners<E>(eventName): (...args) => void[]

Defined in: service-core/node_modules/@types/node/events.d.ts:186

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

Returns​

(...args) => void[]

Since​

v0.1.26

Implementation of​

IWebSocketShim.listeners

Inherited from​

EventEmitter.listeners

off()​

off<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:191

Alias for emitter.removeListener().

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

listener​

(...args) => void

Returns​

this

Since​

v10.0.0

Implementation of​

IWebSocketShim.off

Inherited from​

EventEmitter.off

on()​

on<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:225

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

The name of the event.

listener​

(...args) => void

The callback function

Returns​

this

Since​

v0.1.101

Implementation of​

IWebSocketShim.on

Inherited from​

EventEmitter.on

once()​

once<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:256

Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

The name of the event.

listener​

(...args) => void

The callback function

Returns​

this

Since​

v0.3.0

Implementation of​

IWebSocketShim.once

Inherited from​

EventEmitter.once

prependListener()​

prependListener<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:275

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

The name of the event.

listener​

(...args) => void

The callback function

Returns​

this

Since​

v6.0.0

Implementation of​

IWebSocketShim.prependListener

Inherited from​

EventEmitter.prependListener

prependOnceListener()​

prependOnceListener<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:292

Adds a one-time listener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

The name of the event.

listener​

(...args) => void

The callback function

Returns​

this

Since​

v6.0.0

Implementation of​

IWebSocketShim.prependOnceListener

Inherited from​

EventEmitter.prependOnceListener

rawListeners()​

rawListeners<E>(eventName): (...args) => void[]

Defined in: service-core/node_modules/@types/node/events.d.ts:326

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

Returns​

(...args) => void[]

Since​

v9.4.0

Implementation of​

IWebSocketShim.rawListeners

Inherited from​

EventEmitter.rawListeners

removeAllListeners()​

removeAllListeners<E>(eventName?): this

Defined in: service-core/node_modules/@types/node/events.d.ts:338

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName?​

string | symbol

Returns​

this

Since​

v0.1.26

Implementation of​

IWebSocketShim.removeAllListeners

Inherited from​

EventEmitter.removeAllListeners

removeListener()​

removeListener<E>(eventName, listener): this

Defined in: service-core/node_modules/@types/node/events.d.ts:425

Removes the specified listener from the listener array for the event named eventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events behave as expected.

import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indexes of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

import { EventEmitter } from 'node:events';
const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters​

E​

E extends string | symbol

Parameters​

eventName​

string | symbol

listener​

(...args) => void

Returns​

this

Since​

v0.1.26

Implementation of​

IWebSocketShim.removeListener

Inherited from​

EventEmitter.removeListener

send()​

send(data, cb?): void

Defined in: service-core/src/http/uWS/WebSocket.ts:56

Sends data over the WebSocket connection.

Parameters​

data​

any

The data to send.

cb?​

(err?) => void

Optional callback invoked on completion or error.

Returns​

void

Implementation of​

IWebSocketShim.send

setMaxListeners()​

setMaxListeners(n): this

Defined in: service-core/node_modules/@types/node/events.d.ts:436

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters​

n​

number

Returns​

this

Since​

v0.3.5

Implementation of​

IWebSocketShim.setMaxListeners

Inherited from​

EventEmitter.setMaxListeners