Qler

 

Excruciatingly simple synchronous queuing for node, with concurrency support. It provides similar functionality to p-queue, with the ability to lock concurrency based on a key.

Used in production at https://wellpaid.io.

Installation

``sh
npm install qler


or


yarn add qler
`

API

- queue(fn, key) - queue a promise that returns a promise. Will never run two fns with the same key.
- cancel() - will cancel all remaining queue items and reject any remaining queue promises.
- wait() - wait for all previously queued promises to complete. Returns a promise.

Usage

$3

Execute two functions in sequence, without blocking main thread.

`js
import Qler from "qler";

const myQueue = Qler();

myQueue
.queue(async () => await sleep(2)) // Wait for 2 seconds
.then(() => console.log(Function 1 executed after 2 seconds!));

myQueue
.queue(async () => await sleep(2)) // Wait for 2 seconds
.then(() => console.log(Function 2 executed after 4 seconds!));
`

$3

`js
import Qler from "qler";

const myQueue = Qler(2);

myQueue
.queue(async () => await sleep(2)) // Wait for 2 seconds
.then(() => console.log(Function 1 executed after 2 seconds!));

myQueue
.queue(async () => await sleep(2)) // Wait for 2 seconds
.then(() => console.log(Function 2 executed after 2 seconds!));

myQueue
.queue(async () => await sleep(2)) // Wait for 2 seconds
.then(() => console.log(Function 3 executed after 4 seconds!));
`

$3

Keyed concurrency allows you to limit concurrency to certain function calls. If two or more queued function calls share the same key, they won't be run concurrently.

`js
import Qler from "qler";

const myQueue = Qler(2);

myQueue
.queue(async () => await sleep(2), "foo") // Wait for 2 seconds and key on 'foo'
.then(() => console.log(Function 1 executed after 2 seconds!));

myQueue
.queue(async () => await sleep(2), "foo") // Wait for 2 seconds and key on 'foo'
.then(() => console.log(Function 2 executed after 4 seconds!));

myQueue
.queue(async () => await sleep(2), "bar") // Wait for 2 seconds and key on 'bar'
.then(() => console.log(Function 3 executed after 2 seconds!));
``

License

MIT © Chris Villa