Appolo Thread

Handle your promises in priority queue and control execution concurrency

Installation

npm install appolo-promise-queue --save

Usage

import { Queue } from 'appolo-promise-queue';
import got = require('got');


let queue = new Queue({concurrency: 1});

let promise1 = queue.add(async () => got("somesite"));
let promise2 = queue.add(async () => got("somesite2"));

let [result,result2] = await Promise.all([promise1,promise2])

Api

Queue options:

• concurrency - max concurrent running promises default 1
• timeout - max wait time for promise to settle on the promise wil be rejected default null
• autoStart - start running promises as the added default true
• expire - max time the job can wait in the queue is when passed the job will be removed without execution of the promise
• timespan - time frame in milliseconds of concurrency jobs

const queue = new Queue({
    concurrency: 2, 
    timeout: 1000,
    autoStart: false,
    timespan:60000
});

add(fn,[options])

add job to queue with given Promise-returning/async function

options:

• timeout - override queue timeout for this job.
• priority - job priority in the queue greater priority will be scheduled first.
• expire - max time the job can wait in the queue before it removed.

returns promise when the origin promise settled;

const queue = new Queue();

await queue.add(async ()=>await "something",{timeout:1000,priority:100});

await queue.add(()=>Promise.resolve(),{expire:60000});

start()

Start (or resume) executing enqueued promises

stop()

stop queue execution

onDrain()

Returns a promise that settles when the queue becomes empty

onIdle()

Returns a promise that settles when the queue becomes empty, and all promises have completed

const queue = new Queue();

 queue.add(async ()=>await "something",{timeout:1000,priority:100})
 
 await queue.onIdle();

clear()

clear the queue

size

get current queue size

pending

get current running promises

concurrency

get or set current concurrency

isRunning

return true if queue is not stopped

isDrained

return true if queue is empty

isIdle

return true if queue is empty and no running promises

has(fn)

return true if given fn exists in queue;

remove(fn)

removes given fn from queue

Events

onDrainEvent

fires when queue becomes empty

const queue = new Queue();

 queue.add(async ()=>await "something",{timeout:1000,priority:100})
 
 queue.onDequeueEvent.on(()=>"do something");

onIdleEvent

fires when the queue becomes empty, and all promises have completed

onDequeueEvent

fires when promise pulled from queue and start excitation

onResolvedEvent

fires when promise resolved

License

MIT