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Class: AsyncUtils

Defined in: utils/AsyncUtils.ts:5

Utility methods for running large CPU workloads on the main thread without blocking the UI, by cooperatively yielding to the event loop

Constructors​

Constructor​

new AsyncUtils(): AsyncUtils

Returns​

AsyncUtils

Methods​

createYielder()​

static createYielder(options?): (opts?) => Promise<void>

Defined in: utils/AsyncUtils.ts:53

Creates a time-sliced yielder for loops whose iterations are too coarse or heterogeneous for AsyncUtils.forEach (e.g. nested loops).

Call the returned function at safe points inside a loop: it checks the abort signal on every call for fail-fast cancellation, and additionally yields to the event loop once the time budget since the last yield is exceeded. When within budget and not aborted, it is a cheap no-op.

Parameters​

options?​

Optional time (ms) to run before yielding

yieldMs?​

number

Returns​

The yielder, which takes an optional abort signal

(opts?) => Promise<void>

forEach()​

static forEach<T>(items, callback, options?): Promise<void>

Defined in: utils/AsyncUtils.ts:86

Invokes callback(item, index) for every element of items, yielding to the event loop whenever the time budget is exceeded so the UI stays responsive.

The abort signal is checked up front and after every yield, preserving fail-fast cancellation: an abort rejects with the signal's reason and no further iterations run.

Type Parameters​

T​

T

Parameters​

items​

ArrayLike<T>

The array-like collection to iterate over

callback​

(item, index) => void

Synchronous work to perform for each item and its index

options?​

Optional abort signal, time (ms) to run before yielding (yieldMs), and the number of iterations between budget checks (checkEvery)

checkEvery?​

number

signal?​

AbortSignal

yieldMs?​

number

Returns​

Promise<void>

A promise that resolves once every item has been visited, or rejects with the signal's reason

raceSignal()​

static raceSignal<T>(promise, options?): Promise<T>

Defined in: utils/AsyncUtils.ts:114

Returns a promise that resolves or rejects with the given promise, but rejects early if the given signal is aborted.

Type Parameters​

T​

T

Parameters​

promise​

Promise<T>

The promise to race against the abort signal

options?​

Optional abort signal to race against the promise

signal?​

AbortSignal

Returns​

Promise<T>

A promise that resolves or rejects based on the race condition

yield()​

static yield(): Promise<void>

Defined in: utils/AsyncUtils.ts:22

Yields control back to the event loop, allowing the browser to paint and process input before resuming.

Uses the native scheduler.yield() when available, otherwise falls back to a shared MessageChannel (a macrotask without setTimeout's clamping).

Returns​

Promise<void>

A promise that resolves once the event loop has been yielded to