easy-promise-queue
Easy promise queue. Set a concurrency to execute promises in the queue.
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What is it used for
It's a concurrent queue which can pause.
When its concurrency is set as 1(by default), it's a FIFO queue.
You can put Promises into this queue. Only X promises can be executed concurrently as your configuration.
You can pause/resume this queue at any time. When the queue is paused, ongoing promises will keep running until done though.
Installation
$ npm install easy-promise-queueUsage
How to import
commonJS:
const PromiseQueue = require("easy-promise-queue").default;es2015:
import PromiseQueue from 'easy-promise-queue';How to use
Add Promise thunk to run promise one by one:
let pq = new PromiseQueue({concurrency: 1});
pq.add(() => {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('task 1');
resolve();
}, 1000)
});
});
pq.add(() => {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('task 2');
resolve();
}, 1000)
});
});
// syntax sugar:
pq.add([promiseThunk, promiseThunk, promiseThunk]);
// is equal to:
pq.add(promiseThunk).add(promiseThunk).add(promiseThunk);
// is equal to:
pq.add(promiseThunk);
pq.add(promiseThunk);
pq.add(promiseThunk);
//The added promises will be executed one by one.How to pause the queue:
...
pq.pause();
// you can still add promise, however none of them will run.
pq.resume();
// Promises will resume to run.