From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: PureGero <puregero@gmail.com>
Date: Sun, 26 Jun 2022 11:17:27 +1000
Subject: [PATCH] Optimize CraftServer.getWorld(UUID)

Original license: GPLv3
Original project: https://github.com/MultiPaper/MultiPaper

diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 8fb33258a4949f210eaaadb10effea01b1545ea8..65a8bb881720da73136a26e5031c9972b3cc03c2 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -45,6 +45,8 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import javax.imageio.ImageIO;
+
+import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap;
 import net.minecraft.advancements.Advancement;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.commands.Commands;
@@ -270,6 +272,7 @@ public final class CraftServer implements Server {
     protected final DedicatedServer console;
     protected final DedicatedPlayerList playerList;
     private final Map<String, World> worlds = new LinkedHashMap<String, World>();
+    private final Map<UUID, World> worldsByUUID = new Object2ObjectLinkedOpenHashMap<>(); // MultiPaper - optimize getWorld(UUID)
     private final Map<Class<?>, Registry<?>> registries = new HashMap<>();
     private YamlConfiguration configuration;
     private YamlConfiguration commandsConfiguration;
@@ -1377,6 +1380,7 @@ public final class CraftServer implements Server {
             this.getLogger().log(Level.SEVERE, null, ex);
         }
 
+        this.worldsByUUID.remove(world.getUID()); // MultiPaper - optimize getWorld(UUID)
         this.worlds.remove(world.getName().toLowerCase(java.util.Locale.ENGLISH));
         this.console.removeLevel(handle);
         return true;
@@ -1395,6 +1399,7 @@ public final class CraftServer implements Server {
 
     @Override
     public World getWorld(UUID uid) {
+        if (true) return this.worldsByUUID.get(uid); // MultiPaper - optimize getWorld(UUID)
         for (World world : this.worlds.values()) {
             if (world.getUID().equals(uid)) {
                 return world;
@@ -1418,6 +1423,7 @@ public final class CraftServer implements Server {
             System.out.println("World " + world.getName() + " is a duplicate of another world and has been prevented from loading. Please delete the uid.dat file from " + world.getName() + "'s world directory if you want to be able to load the duplicate world.");
             return;
         }
+        this.worldsByUUID.put(world.getUID(), world); // MultiPaper - optimize getWorld(UUID)
         this.worlds.put(world.getName().toLowerCase(java.util.Locale.ENGLISH), world);
         MultiPaper.broadcastPacketToExternalServers(new SubscribeToWorldPacket(world.getName())); // MultiPaper
     }