Improve uuid cache load times

[Warriorrrr]

Information

This PR fixes n/a

Details

Currently, the plugin can take a long time to load depending on the size of the uuids.bin file.

Proposed fix:

Replace the set implementation used by the uuid cache with a concurrenthasthmap backed set.

Environments tested:

OS: Ubuntu 20.04

Java version: 17.0.1

• Most recent Paper version (1.XX.Y, git-Paper-BUILD)
• CraftBukkit/Spigot/Paper 1.12.2
• CraftBukkit 1.8.8

Demonstration:

Before

[18:29:28 INFO]: [Essentials] Enabling Essentials v2.20.0-dev+15-20011b9
[18:36:02 INFO]: [Essentials] Loaded 38132 items from items.json.

Jstack

"Server thread" prio=7 os_prio=0 cpu=254434.36ms elapsed=256.38s tid=0x00007f33c4503e10 nid=0x37616e runnable [0x00007f33d81fa000] java.lang.Thread.State: RUNNABLE at java.util.concurrent.CopyOnWriteArrayList.indexOfRange(java.base@17.0.1/CopyOnWriteArrayList.java:193) at java.util.concurrent.CopyOnWriteArrayList.indexOf(java.base@17.0.1/CopyOnWriteArrayList.java:238) at java.util.concurrent.CopyOnWriteArrayList.contains(java.base@17.0.1/CopyOnWriteArrayList.java:230) at java.util.concurrent.CopyOnWriteArraySet.contains(java.base@17.0.1/CopyOnWriteArraySet.java:157) at com.earth2me.essentials.userstorage.ModernUUIDCache.loadCache(ModernUUIDCache.java:178) at com.earth2me.essentials.userstorage.ModernUUIDCache.(ModernUUIDCache.java:57) at com.earth2me.essentials.userstorage.ModernUserMap.(ModernUserMap.java:33) at com.earth2me.essentials.Essentials.onEnable(Essentials.java:313) at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:264) at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:370) at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:542) - locked <0x000000070a8aada0> (a org.bukkit.plugin.SimplePluginManager) at org.bukkit.craftbukkit.v1_19_R1.CraftServer.enablePlugin(CraftServer.java:565) at org.bukkit.craftbukkit.v1_19_R1.CraftServer.enablePlugins(CraftServer.java:479)

After

[18:53:41 INFO]: [Essentials] Enabling Essentials v2.20.0-dev+15-20011b9
[18:53:42 INFO]: [Essentials] Loaded 38132 items from items.json.