Sidebar performance issue and possible memory leak

[datokrat]

Problem

Open and close pages in the sidebar. Both operations will get slower and slower until they become unusable and freeze Athens. Here is what the profiler says:

As far as I understand, the map operations assoc and dissoc on (:right_sidebar/items app-db) become inefficient. I believe this a problem with the immutable data structures of CLJS, since (:right_sidebar/items app-db) contained only two elements, so that dissoc should definitely be fast. I suspect that the reduce-kv and sorted-map-by calls in :right-sidebar/open-item somehow modify the internal data structure of the map in a very unfortunate way. Very strange.

Demo

https://www.loom.com/share/b74d5768d029432b92f6cc05b02359d7

Athens version

BETA-82 (Electron, Linux)

[datokrat]

I think I found the problem. It has to do with the compare function, which is a closure that holds a reference to an earlier version of the map of sidebar items, which again has a compare function holding a reference to an earlier version of the map and so on.

I'll make a short video showing the evidence.

[datokrat]

See this demo:

https://www.loom.com/share/3a3c368f30ca4a939dc79917ede0e477

[datokrat]

Here is my PR for a fix. #1242