Accessing indexedDB in ServiceWorker. Race condition

Question

There aren\'t many examples demonstrating indexedDB in a ServiceWorker yet, but the ones I saw were all structured like this:

const request = indexedDB.open(         


        

Answer 1

Opening the IDB every time the ServiceWorker starts up is unlikely to be optimal, you'll end up opening it even when it isn't used. Instead, open the db when you need it. A singleton is really useful here (see https://github.com/jakearchibald/svgomg/blob/master/src/js/utils/storage.js#L5), so you don't need to open IDB twice if it's used twice in its lifetime.

The "activate" event is a great place to open IDB and let any "onupdateneeded" events run, as the old version of ServiceWorker is out of the way.