Auditorium (v1) becomes unresponsive when lots of users are moving around

[0xdevalias]

I've tested the venue page with around 1000 audiences.

..snip..

I've noticed that the page becomes somewhat unresponsive when there are a lot of people moving around. This might be an issue when an event starts up and suddenly a whole bunch of people trying find spots.

Originally posted by @soichih in #1434

[0xdevalias]

Also, I've noticed that the page becomes somewhat unresponsive when there are a lot of people moving around. This might be an issue when an event starts up and suddenly a whole bunch of people trying find spots.

@soichih Yeah, that doesn't surprise me to be honest. The current implementation/memoisation there definitely isn't super performance optimised at the moment.

I would have to look at it closer again to be certain, but from memory there are way more things crammed into a single useMemo than there should be (which will cause it to break memoisation more often than it should), as well as the 'seat grid' being a fairly inefficient n^2 nested loop currently, creating a fairly large amount of div elements (which can be a little overwhelming in itself), as well as probably not being laid out in the best way (causing them to need to be redrawn more often)

We have a somewhat similar grid pattern implemented on the PartyMap Map, that is using slightly newer/better code (abstracted into some hooks). Though even that code isn't perfect, and likely still isn't as efficient as it could be.

Breaking down the useMemo into smaller 'relevant chunks' is probably the easier of the 2 issues here.

Finding an efficient way to refactor the n^2 nested loops used to build the 'grid of seats' is probably the harder problem, but I expect may lead to the best gains here. My gut feel is that there should be a way for us to represent it in a fairly 'flat' way using CSS grid, or flexbox, or similar; but haven't had the opportunity to dive into that and really figure it out yet.

Originally posted by @0xdevalias in #1434 (comment)