Queue promises into pool limiting concurrency
Install with npm:
$ npm install --save promise-pool-ext
import { Pool } from 'promise-pool-ext';
const pool = Pool({ concurrency: 10 });
// queue array of functions, returns Promise < array of function results >
pool([
() => new Promise((resolve) => { /* do async logic here */ }),
async () => { /* do async logic here */ }
]);
// queue function, returns Promise < function result >
pool(async () => { /* do async logic here */ });See tests for more examples
import { PoolManager } from 'promise-pool-ext';
const manager = PoolManager({
check1: {
if: () => false, // when not true returned, promise is not resolved and undefined is returned
fn: () => { /* return async logic */ }
},
check2: {
requires: ['check1'],
fn: ({ check1 }) => {
if (check1) { /* return async logic */ }
}
},
data: {
requires: ['check1', 'check2'],
fn: ({ check1, check2 }) => {
if (check1 && check2) { /* return async logic */ }
}
}
}, { concurrency: 10 });
// returns Promise < data.fn result >
manager.get('data');See tests for more examples
How many promises can resolve in parallel.
Maximum amount of time in ms that a promise can take to resolve before a failure is returned.
If 0 or undefined is passes, no timeout is enforced.
When a promise is rejected or an error is thrown, the returned promise is rejected once all promises in batch have completed execution.
As an example, when making a lot of external requests one can hit limits of the external API or the node runtime itself. This library makes it easy to limit the amount of parallel executions.