The current system has bad performance when you've got 100,000+ tags.
I discovered that when the server returns 304, the browser gives the
ajax a 200 with the full response, and it's not clear to me if js can
know it got a 304. So, the tag set is being fully re-parsed from the
response on every page load. I was thinking that I should store that in
IndexedDB to avoid the parsing step, but... since the JSON.parse is
done by my common.get before it hits this function, it's meaningless.
Not to mention I still have to rebuild the datalist on every page since
of course that state isn't shared between tabs. Not worth the DB stuff.
We'll see what happens next.