pooledMap

function

function pooledMap<T, R>(poolLimit: number, array: Iterable<T> | AsyncIterable<T>, iteratorFn: (data: T) => Promise<R>): AsyncIterableIterator<R>

pooledMap transforms values from an (async) iterable into another async iterable. The transforms are done concurrently, with a max concurrency defined by the poolLimit.

If an error is thrown from iterableFn, no new transformations will begin. All currently executing transformations are allowed to finish and still yielded on success. After that, the rejections among them are gathered and thrown by the iterator in an AggregateError.

poolLimit: number

The maximum count of items being processed concurrently. Must be a positive integer.

array: Iterable<T> | AsyncIterable<T>

The input array for mapping.

iteratorFn: (data: T) => Promise<R>

The function to call for every item of the array.

Returns

The async iterator with the transformed values.

import { pooledMap } from "@ende/async/pool";
import { assertEquals } from "@ende/assert";

const results = pooledMap(
  2,
  [1, 2, 3],
  (i) => new Promise((r) => setTimeout(() => r(i), 1000)),
);

assertEquals(await Array.fromAsync(results), [1, 2, 3]);