pseudo-ish code change queue

queue.js

const saveQueue = [
  slide,
  slide1,
  slide2,
  slide
];

const attemptedSlides = {};
const running = false;

addToQueue (slide) {
  saveQueue.push(slide);

  if (!running) {
    processQueue();
  }
}

processQueue() {
  const itemToSave = saveQueue.shift();

  if (typeof itemToSave !== 'undefined') {
    running = true;
    
    if (attemptedSlides[itemToSave.id]){
      attemptedSlides[itemToSave.id] ++;
    } else {
      attemptedSlides[itemToSave.id] = 1;
    }

    saveFunction(itemToSave).then(() => {
      attemptedSlides[itemToSave.id] = undefined;
      setTimeout(processQueue, 0); // setTimeout to release the thread
    }, () => {
      if (attemptedSlides[itemToSave.id] < 3) {
        saveQueue.unshift(itemToSave);
        setTimeout(processQueue, 100); // wait 100 ms to see if things get better
      } else {
        setTimeout(processQueue, 0); // exceeded attempts... sorry man
      }
    });
  } else {
    running = false;
  }
}

Seems pretty legit!

a couple other things I am thinking about... the particular item in the queue should probably only exist once. So If I save a new thing it should replace the existing instance of the thing that is in the queue. Since we are doing PUTs instead of PATCHs.

It should probably notify the user in some way that things are less then optimal... and have a smarter retry based around the response codes.

I am also trying to decide between a deep clone when the item is added or just letting it be passed by reference. Pass by reference makes the dedupe easy because you just check to see if that thing is already enqueued and then bail on adding it if it is. Where as the deep clone would allow you to do gradual updates of the object.

I am leaning towards no deep clone... seems a little more elegant to me.