@sapphire/async-queue

What is @sapphire/async-queue?

@sapphire/async-queue is a utility for managing asynchronous tasks in a sequential manner. It ensures that tasks are executed one after another, preventing race conditions and ensuring order.

What are @sapphire/async-queue's main functionalities?

Basic Queue Usage

This code demonstrates the basic usage of @sapphire/async-queue. It creates a queue and ensures that task1 and task2 are executed sequentially.

const { AsyncQueue } = require('@sapphire/async-queue');

const queue = new AsyncQueue();

async function task1() {
  await queue.wait();
  console.log('Task 1 started');
  setTimeout(() => {
    console.log('Task 1 completed');
    queue.shift();
  }, 1000);
}

async function task2() {
  await queue.wait();
  console.log('Task 2 started');
  setTimeout(() => {
    console.log('Task 2 completed');
    queue.shift();
  }, 500);
}

task1();
task2();

Handling Errors in Queue

This code demonstrates how to handle errors within the queue. Even if a task throws an error, the queue continues to process the next task.

const { AsyncQueue } = require('@sapphire/async-queue');

const queue = new AsyncQueue();

async function taskWithError() {
  await queue.wait();
  console.log('Task with error started');
  setTimeout(() => {
    console.log('Task with error encountered an error');
    queue.shift();
    throw new Error('Task error');
  }, 1000);
}

async function taskAfterError() {
  await queue.wait();
  console.log('Task after error started');
  setTimeout(() => {
    console.log('Task after error completed');
    queue.shift();
  }, 500);
}

taskWithError().catch(console.error);
taskAfterError();

Other packages similar to @sapphire/async-queue

async

The 'async' package provides a wide range of utilities for working with asynchronous JavaScript. It includes functions for parallel and sequential execution, among others. Compared to @sapphire/async-queue, 'async' offers more comprehensive functionality but can be more complex to use for simple sequential task management.

p-queue

The 'p-queue' package is a promise queue with concurrency control. It allows you to manage the execution of promises with a specified concurrency level. While 'p-queue' offers more advanced features like concurrency control, @sapphire/async-queue focuses on simple sequential execution.

queue

The 'queue' package is a simple and efficient queue implementation for Node.js. It supports basic queue operations and is easy to use. Compared to @sapphire/async-queue, it lacks built-in support for asynchronous task management but can be extended for such use cases.

README

@sapphire/async-queue

Sequential asynchronous lock-based queue for promises.

Table of Contents

• Features
• Installation
• Usage
• Buy us some doughnuts
• Contributors

Features

• Written in TypeScript
• Bundled with esbuild so it can be used in NodeJS and browsers
• Offers CommonJS, ESM, and UMD bundles
• Fully tested

Installation

You can use the following command to install this package, or replace npm install with your package manager of choice.

npm install @sapphire/async-queue

Usage

Note: While this section uses require, the imports match 1:1 with ESM imports. For example const { AsyncQueue } = require('@sapphire/async-queue') equals import { AsyncQueue } from '@sapphire/async-queue'.

// Require the AsyncQueue class
const { AsyncQueue } = require('@sapphire/async-queue');

const queue = new AsyncQueue();

async function request(url, options) {
	// Wait and lock the queue
	await queue.wait();

	try {
		// Perform the operation sequentially
		return await fetch(url, options);
	} finally {
		// Unlock the next promise in the queue
		queue.shift();
	}
}

request(someUrl1, someOptions1);
// Will call fetch() immediately

request(someUrl2, someOptions2);
// Will call fetch() after the first finished

request(someUrl3, someOptions3);
// Will call fetch() after the second finished

---

Buy us some doughnuts

Sapphire Community is and always will be open source, even if we don't get donations. That being said, we know there are amazing people who may still want to donate just to show their appreciation. Thank you very much in advance!

We accept donations through Open Collective, Ko-fi, PayPal, Patreon, and GitHub Sponsorships. You can use the buttons below to donate through your method of choice.

Donate With	Address
Open Collective	Click Here
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PayPal	Click Here

Contributors

Please make sure to read the Contributing Guide before making a pull request.

Thank you to all the people who already contributed to Sapphire!