promise queue javascript code example

Example: promise queue javascript

// promise queue
const Queue = require('promise-queue');
var maxConcurrent = 1;
var maxQueue = Infinity;
var queue = new Queue(maxConcurrent, maxQueue);

(async () => {
    const promises = [];
    // logic here
    function getDownloader() {
        return async () => {
            await new Promise((res, rej) => {
                setTimeout(() => {
                    console.log("hello data");
                    res();
                }, 3000);
            })
        };
    }

    for (let i = 0; i < 4; i++) {
        promises.push(queue.add(getDownloader()))
    }

    const start = Date.now()
    await Promise.all(promises)
    console.log(Date.now() - start)

})()