Comment by timokoesters | Hacker News Reader

Comment by timokoesters | Hacker News Reader

- Sliding sync: This is great and I can't wait to see it in action.

I hope the performance problems on Element Android will be fixed as well. Sometimes it takes a second for me for a room to open after I clicked on it. Using Hydrogen in a web browser feels so much better.

- Fast remote joins: I think this treats the symptoms of a problem rather than the cause.

Rooms should not contain so much data. Do users really need a state event per room (+all their history) or can it be optimized to one state event per server? I'm in the process of writing an MSC for this.

Alternatively, instead of half-joining the room, you could add features to room 'peeking' so that you can fully interact with a remote room without persisting the room on the server at all.

Element Android’s UI performance problems are thanks to using Realm as a single source of truth and then calling it synchronously rather than async - this is being fixed currently irrespectively of sliding sync or element x etc.

For fast remote joins: however you express the state events per room, there’s no excuse to block joining the room on having all the state. In fact, the original driver for fast joins was me implementing peeking over federation in Dendrite and needing a fast way to look at the state in the room.

Unsure that having one membership event per server rather than per user is obviously a win - it’s the same amount of info in the end, plus you’ll hit the 65K event limit as well as increasing chance of races (within the server) if you put all users in the same event for a given server. Feel free to prove me wrong tho :)

On the other hand, we definitely need a way to delete irrelevant old state, and there’s a bunch of work happening around that currently.

What counts as "irrelevant old state"?

the obvious thing is “the fact this user used to be in the room and left”. nobody cares, unless you are looking at historical messages from when they were in the room.

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