paket-queue

About

Croatian for "Pack", paket-queue is a promisified queue batch library that allows you to re-route individual calls to a function or method capable of handling batched data.

Usage

This library has been made with databases in mind, but can be used for literally any other purpose as it is abstracted. Let's say you have a class handling all database interactions, and you have a get and a getAll methods. And you want to make it so, when your application calls the get method 10 times or more, they get re-routed to the getAll method.

This is simple with paket-queue:

// Or `const { Queue } = require('paket-queue');` in CommonJS
import { Queue } from 'paket-queue';

class Provider {

	connection = new DatabaseConnection(/* arguments */);
	queue = new Queue(ids => this.getAll(ids), 10);

	get(id) {
		return queue.run(id, () => connection.get(id));
	}

	getAll(ids) {
		return connection.getAll(id);
	}

}

Now when you run Provider#get 10 times or more in the same tick, no call to connection.get will be done, instead, all the ids will be sent to Provider#getAll.

Batching

Another feature of paket-queue, is that it supports batching:

const results = await Promise.all([
	paket.run('foo', id => connection.get(id)),
	paket.run('foo', id => connection.get(id)),
	paket.run('foo', id => connection.get(id))
]);

This will internally count as a single item, and the return will be an array of 3 elements, all of which will be references of (meaning results[0] === results[1] && results[1] === results[2]), as get is only called once and the same value is passed to all of them.

Extending

While this library only exports the Queue class, it is possible to extend its functionality, e.g. increasing the timer to be of 50 milliseconds instead of the following tick can be achieved with the following:

// Or `const { Queue } = require('paket-queue');` in CommonJS
import { Queue } from 'paket-queue';

class MyQueue extends Queue {

	createTimer() {
		setTimeout(() => this.handleNextTick(), 50);
	}

}

In TypeScript, you can also do this, Queue#createTimer is protected, meaning it is accessible for Queue's extensions.

Contributing

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request!

Author

paket-queue © kyranet, released under the MIT License. Authored and maintained by kyranet.

Github kyranet - Twitter @kyranet_