pooledMap

function · experimental

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

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

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.

poolLimit: number

The maximum count of items being processed concurrently.

Returns

The async iterator with the transformed values.

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

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

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

function · experimental

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

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

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.

options: PooledMapOptions

Configuration for concurrency and cancellation.

Returns

The async iterator with the transformed values.

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

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

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

import { pooledMap } from "@ende/async/unstable-pool";
import { assertRejects } from "@ende/assert";

const controller = new AbortController();
const results = pooledMap(
  [1, 2, 3, 4, 5],
  (i) => new Promise((r) => setTimeout(() => r(i), 1000)),
  { poolLimit: 2, signal: controller.signal },
);

controller.abort(new Error("cancelled"));

await assertRejects(
  () => Array.fromAsync(results),
  Error,
  "cancelled",
);

function · experimental

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