promise-pull-queue

A promise queue class for handling pull based async tasks. Pushed results will be pulled in-order and pulled-deferreds will be resolve in-order as results are received.

Installation

``sh
npm i --save promise-pull-queue
`

Usage

#### Supports both ESM and CommonJS

`js
// esm
import PullQueue from 'promise-pull-queue
// commonjs
const PullQueue = require('promise-pull-queue').default
``

#### Push promised results onto the queue and pull them later

`js
import PullQueue from 'promise-pull-queue

const queue = PullQueue()
queue.push(Promise.resolve(100))
queue.push(Promise.resolve(200))
queue.push(Promise.resolve(300))

// some time later
await queue.pull() // 100
await queue.pull() // 200
await queue.pull() // 300
``

#### Pull promised results off the queue and wait for future results

`js
import PullQueue from 'promise-pull-queue

const queue = PullQueue()

let resolve1
const p1 = new Promise(resolve => {
resolve1 = resolve
})
let resolve2
const p2 = new Promise(resolve => {
resolve2 = resolve
})
let resolve3
const p3 = new Promise(resolve => {
resolve3 = resolve
})

queue.push(p1)
queue.push(p2)
queue.push(p3)

setTimeout(() => {
// promises resolved later
resolve1(100)
resolve2(200)
resolve3(300)
}, 100)

// wait for promised results
await Promise.all([
queue.pull(), // 100
queue.pull(), // 200
queue.pull() // 300
])
``

#### Pull deferred results off the queue and wait for future promised results

`js
import PullQueue from 'promise-pull-queue

const queue = PullQueue()

setTimeout(() => {
// promised results pushed later
queue.push(Promise.resolve(100))
queue.push(Promise.resolve(200))
queue.push(Promise.resolve(300))
}, 100)

// wait for results, before any are pushed
await Promise.all([
queue.pull(), // 100
queue.pull(), // 200
queue.pull() // 300
])
``

#### Pull deferred results off the queue and wait for future promised results, but cancel some

`js
import PullQueue from 'promise-pull-queue

const queue = PullQueue()

setTimeout(() => {
// promised results pushed later
queue.push(Promise.resolve(100))
queue.push(Promise.resolve(200))
queue.push(Promise.resolve(300))
}, 100)

// wait for results, before any are pushed
const controller = new AbortController()
controller.abort()
await Promise.all([
queue.pull(controller.signal), // [AbortError aborted]
queue.pull(), // 100
queue.pull(), // 200
queue.pull() // 300
]) // [AbortError aborted]
```

License

MIT