Holographic Displays

Confirmation

I have read the FAQ.
I have tested the latest development build of Holographic Displays and the bug is still present.
I have updated Spigot to the latest release for my particular Minecraft version.
I made sure the bug hasn't already been reported on the issue tracker.

Description

HolographicDisplays/plugin/src/main/java/me/filoghost/holographicdisplays/plugin/tick/TickingTask.java

Line 26 in 90e26af

private final WeakHashMap<Player, CachedPlayer> cachedPlayersMap;

The cachedPlayerMap in TickingTask seems to be leaking a lot of memory, especially on larger servers where there's a lot of players online concurrently. In the screenshot below, the map can be observed to be having about 3000 entries (over 500M of memory), even though there are less than 10 players online (this is on our hub server).

This seems to be caused by the CachedPlayer object holding a strong reference to Player, which is also the value's own key in the map. From WeakHashMap's javadoc:

Implementation note: The value objects in a WeakHashMap are held by ordinary strong references. Thus care should be taken to ensure that value objects do not strongly refer to their own keys, either directly or indirectly, since that will prevent the keys from being discarded.

How to reproduce

Install Holographic Displays build 186 or newer
Let players join server and wait
Take a heap dump / attach debugger or analyzer, and observe map growing in size

Server version

This server is running Purpur version git-Purpur-"66e5b11" (MC: 1.17.1) (Implementing API version 1.17.1-R0.1-SNAPSHOT) (Git: 66e5b11 on ver/1.17.1)