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downflux

downflux / ProgressManager

Class: ProgressManager

Defined in: packages/core/progress/ProgressManager.ts:20

Manages progress updates during ExecutionCoordinator execution.

Emits 'progress' events with the current state of the ExecutionCoordinator, which can be used for rendering progress in the UI or CLI.

The update method is used to update the current state of the ExecutionCoordinator and emit progress events at a controlled interval to avoid excessive updates.

Requires: must call init with ExecutionOptions before use to set up callbacks and options

Extends

  • EventEmitter

Constructors

Constructor

new ProgressManager(options?): ProgressManager

Defined in: node_modules/.pnpm/@types+node@25.6.0/node_modules/@types/node/events.d.ts:54

Parameters

options?

EventEmitterOptions

Returns

ProgressManager

Inherited from

EventEmitter.constructor

Methods

[captureRejectionSymbol]()?

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

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.[captureRejectionSymbol]

addListener()

addListener<E>(eventName, listener): this

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.addListener

eventNames()

eventNames(): (string | symbol)[]

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.eventNames

getMaxListeners()

getMaxListeners(): number

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.getMaxListeners

listenerCount()

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

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.listenerCount

listeners()

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

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.listeners

prependListener()

prependListener<E>(eventName, listener): this

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.prependListener

prependOnceListener()

prependOnceListener<E>(eventName, listener): this

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.prependOnceListener

rawListeners()

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

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.rawListeners

removeAllListeners()

removeAllListeners<E>(eventName?): this

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.removeAllListeners

removeListener()

removeListener<E>(eventName, listener): this

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.removeListener

setMaxListeners()

setMaxListeners(n): this

Defined in: node_modules/.pnpm/@types+node@25.6.0/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

Inherited from

EventEmitter.setMaxListeners

on()

on<E>(eventName, listener): this

Defined in: packages/core/progress/ProgressManager.ts:43

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 "progress"

Parameters

eventName

E

The name of the event.

listener

ProgressEvents[E]

The callback function

Returns

this

Since

v0.1.101

Overrides

EventEmitter.on

emit()

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

Defined in: packages/core/progress/ProgressManager.ts:47

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 "progress"

Parameters

eventName

E

args

...Parameters<ProgressEvents[E]>

Returns

boolean

Since

v0.1.26

Overrides

EventEmitter.emit

off()

off<E>(eventName, listener): this

Defined in: packages/core/progress/ProgressManager.ts:51

Alias for emitter.removeListener().

Type Parameters

E

E extends "progress"

Parameters

eventName

E

listener

ProgressEvents[E]

Returns

this

Since

v10.0.0

Overrides

EventEmitter.off

once()

once<E>(eventName, listener): this

Defined in: packages/core/progress/ProgressManager.ts:55

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 "progress"

Parameters

eventName

E

The name of the event.

listener

ProgressEvents[E]

The callback function

Returns

this

Since

v0.3.0

Overrides

EventEmitter.once

init()

init(options): void

Defined in: packages/core/progress/ProgressManager.ts:59

Parameters

options

ExecutionOptions

Returns

void

update()

update(params): void

Defined in: packages/core/progress/ProgressManager.ts:67

Parameters

params

Partial<JobProgressEvent>

Returns

void