Intro

queue is a simple queueing tool for JS.

Installation

``bash
npm install --save https://github.com/jrc03c/queue
`

Usage

Node / bundlers:

`js
const Queue = require("@jrc03c/queue")
`

Browser:

`html

`

Then:

`js
async function run(){
const timeBetweenJobs = 1000
const queue = new Queue(timeBetweenJobs)

// Option 1: append an async function to the queue, which returns an ID; then
// retrieve the result using the ID later.
const id1 = queue.append(async () => {
const response = await fetch(...)
return await response.json()
})

const result1 = await queue.retrieve(id)

// Option 2: Do both steps using the single process function.
const result2 = await queue.process(async () => {
const response = await fetch(...)
return await response.json()
})
}

run()
`

API

Queue

The Queue class is the primary tool in this library. As you append jobs (i.e., asynchronous functions) to the queue, the queue processes them one-at-a-time, in order, with a short pause after each job is finished.

$3

#### jobs

An array of "jobs" where each job is a dictionary containing id and fn properties.

#### results

A dictionary of ID-value pairs.

#### interval

The thing returned from setInterval when .start() is called.

#### isRunning

A boolean indicating whether or not the queue is actively processing jobs.

#### timeBetweenJobs

A number indicating a time in milliseconds to wait after each job finishes before starting the next job.

$3

#### new Queue(timeBetweenJobs=100)

The only argument to the Queue constructor is the amount of time (in milliseconds) to wait between jobs. The default value is 100 milliseconds.

#### .append(asyncFunction)

Appends an asynchronous function to the list of jobs to process and returns an ID that points to that job.

#### .retrieve(ID)

Returns a Promise that resolves to the output of the job.

#### .process(asyncFunction)

Returns a Promise that resolves to the output of the job. This function is exactly like calling .append(asyncFunction) and then .retrieve(ID).

#### .start()

Starts the processing of the list of jobs. Normally, this doesn't need to be called manually; it's called automatically as soon as a job is appended to the list of jobs.

#### .stop()

Stops the processing of the list of jobs. Any jobs that are being processed when this method is called will _not_ be stopped; they will finish as usual and store their results. Normally, this doesn't need to be called manually; it's called automatically as soon as the job list becomes empty.

#### .destroy()

Stops the processing of the list of jobs and then sets all properties to null`.