Typing in a conversation got progressively slower as its history grew.
The cause was not the input: every packet the node overhears was stored
in App state, so each one re-rendered the whole tree, including the
un-memoized MessageList. That cost scales with history length, and on a
busy mesh it saturated the main thread so keystrokes queued behind it.
Measured in Chromium with the real components, cost per overheard packet:
history before after
50 7.3ms ~0ms
500 48.5ms ~0ms
1000 97.7ms ~0ms
2000 228.4ms ~0ms
The packet stream now lives in a small external store that views subscribe
to individually, so only the map, visualizer, raw feed, and cracker re-render
when a packet arrives, so the chat view is no longer along for the ride.
This also retires useRawPacketStatsSession, whose session state was App
state for the same reason.
Ryan Gregg