Fix Fabric build script and implement the fabric-plugin

BlueMapCommon/src/main/java/de/bluecolored/bluemap/common/plugin/MapUpdateHandler.java

@@ -38,15 +38,18 @@
 
 public class MapUpdateHandler implements ServerEventListener {
 
-	public Multimap<MapType, Vector2i> updateBuffer;
+	private Plugin plugin;
 	
-	public MapUpdateHandler() {
+	private Multimap<MapType, Vector2i> updateBuffer;
+	
+	public MapUpdateHandler(Plugin plugin) {
+		this.plugin = plugin;
 		updateBuffer = MultimapBuilder.hashKeys().hashSetValues().build();
 	}
 	
 	@Override
 	public void onWorldSaveToDisk(final UUID world) {
-		RenderManager renderManager = Plugin.getInstance().getRenderManager();
+		RenderManager renderManager = plugin.getRenderManager();
 		
 		new Thread(() -> {
 			try {
@@ -106,7 +109,7 @@ private void updateChunk(UUID world, Vector2i chunkPos) {
 	
 	private void updateBlock(UUID world, Vector3i pos){
 		synchronized (updateBuffer) {
-			for (MapType mapType : Plugin.getInstance().getMapTypes()) {
+			for (MapType mapType : plugin.getMapTypes()) {
 				if (mapType.getWorld().getUUID().equals(world)) {
 					mapType.getWorld().invalidateChunkCache(mapType.getWorld().blockPosToChunkPos(pos));
 					
@@ -122,7 +125,7 @@ public int getUpdateBufferCount() {
 	}
 	
 	public void flushTileBuffer() {
-		RenderManager renderManager = Plugin.getInstance().getRenderManager();
+		RenderManager renderManager = plugin.getRenderManager();
 		
 		synchronized (updateBuffer) {
 			for (MapType map : updateBuffer.keySet()) {

BlueMapCommon/src/main/java/de/bluecolored/bluemap/common/plugin/Plugin.java

@@ -72,8 +72,6 @@ public class Plugin {
 
 	public static final String PLUGIN_ID = "bluemap";
 	public static final String PLUGIN_NAME = "BlueMap";
-
-	private static Plugin instance;
 	
 	private BlueMapAPIImpl api;
 	
@@ -104,8 +102,6 @@ public Plugin(String implementationType, ServerInterface serverInterface) {
 		
 		this.maps = new HashMap<>();
 		this.worlds = new HashMap<>();
-		
-		instance = this;
 	}
 	
 	public synchronized void load() throws IOException, ParseResourceException {
@@ -270,7 +266,7 @@ public synchronized void load() throws IOException, ParseResourceException {
 		periodicalSaveThread.start();
 		
 		//start map updater
-		this.updateHandler = new MapUpdateHandler();
+		this.updateHandler = new MapUpdateHandler(this);
 		serverInterface.registerListener(updateHandler);
 		
 		//create/update webfiles
@@ -427,8 +423,4 @@ public boolean isLoaded() {
 		return loaded;
 	}
 	
-	public static Plugin getInstance() {
-		return instance;
-	}
-	
 }

BlueMapFabric/build.gradle

@@ -5,7 +5,7 @@ plugins {
 }
 
 configurations {
-	compile.extendsFrom include
+	compile.extendsFrom shadowInclude
 }
 
 dependencies {
@@ -14,7 +14,7 @@ dependencies {
 	modImplementation "net.fabricmc:fabric-loader:0.8.2+build.194"
 	modImplementation "net.fabricmc.fabric-api:fabric-api:0.5.1+build.294-1.15"
 
-	compile (project(':BlueMapCommon')) {
+	shadowInclude (project(':BlueMapCommon')) {
     	//exclude dependencies provided by fabric
 		exclude group: 'com.google.guava', module: 'guava'
 		exclude group: 'com.google.code.gson', module: 'gson'
@@ -38,13 +38,7 @@ processResources {
 }
 
 shadowJar {
-	configurations = [project.configurations.compile]
-
-	dependencies {
-		include(dependency(':BlueMapCommon'))
-		include(dependency(':BlueMapCore'))
-		include(dependency(':BlueMapAPI'))
-	}
+	configurations = [project.configurations.shadowInclude]
 
 	//relocate 'com.flowpowered.math', 'de.bluecolored.shadow.flowpowered.math' //DON'T relocate this, because the API depends on it
 	relocate 'com.typesafe.config', 'de.bluecolored.shadow.typesafe.config'
@@ -52,7 +46,7 @@ shadowJar {
 	relocate 'ninja.leaping.configurate', 'de.bluecolored.shadow.ninja.leaping.configurate'
 	relocate 'org.yaml.snakeyaml', 'de.bluecolored.shadow.yaml.snakeyaml'
 
-	exclude '/mappings/*'
+	//exclude '/mappings/*'
 }
 
 task ramappedShadowJar(type: RemapJarTask) {
@@ -62,6 +56,7 @@ task ramappedShadowJar(type: RemapJarTask) {
 	addNestedDependencies = true
 	archiveName = "BlueMap-${version}-fabric.jar"
 }
+build.dependsOn ramappedShadowJar
 
 task sourcesJar(type: Jar, dependsOn: classes) {
 	classifier = "sources"

BlueMapFabric/src/main/java/de/bluecolored/bluemap/fabric/FabricEventForwarder.java

@@ -0,0 +1,95 @@
+package de.bluecolored.bluemap.fabric;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.UUID;
+
+import com.flowpowered.math.vector.Vector2i;
+import com.flowpowered.math.vector.Vector3i;
+
+import de.bluecolored.bluemap.common.plugin.serverinterface.ServerEventListener;
+import de.bluecolored.bluemap.core.logger.Logger;
+import de.bluecolored.bluemap.fabric.events.ChunkFinalizeCallback;
+import de.bluecolored.bluemap.fabric.events.WorldSaveCallback;
+import net.fabricmc.fabric.api.event.player.AttackBlockCallback;
+import net.fabricmc.fabric.api.event.player.UseBlockCallback;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Direction;
+import net.minecraft.world.World;
+
+public class FabricEventForwarder {
+
+	private FabricMod mod;
+	private Collection<ServerEventListener> eventListeners;
+	
+	public FabricEventForwarder(FabricMod mod) {
+		this.mod = mod;
+		this.eventListeners = new ArrayList<>(1);
+		
+		WorldSaveCallback.EVENT.register(this::onWorldSave);
+		ChunkFinalizeCallback.EVENT.register(this::onChunkFinalize);
+		AttackBlockCallback.EVENT.register(this::onBlockAttack);
+		UseBlockCallback.EVENT.register(this::onBlockUse);
+	}
+	
+	public void addEventListener(ServerEventListener listener) {
+		this.eventListeners.add(listener);
+	}
+	
+	public void removeAllListeners() {
+		this.eventListeners.clear();
+	}
+	
+
+	public ActionResult onBlockUse(PlayerEntity player, World world, Hand hand, BlockHitResult hitResult) {
+		if (world instanceof ServerWorld) {
+			onBlockChange((ServerWorld) world, hitResult.getBlockPos());
+		}
+		
+		return ActionResult.PASS;
+	}
+	
+	public ActionResult onBlockAttack(PlayerEntity player, World world, Hand hand, BlockPos pos, Direction direction) {
+		if (world instanceof ServerWorld) {
+			onBlockChange((ServerWorld) world, pos);
+		}
+		
+		return ActionResult.PASS;
+	}
+	
+	public void onBlockChange(ServerWorld world, BlockPos blockPos) {
+		Vector3i position = new Vector3i(blockPos.getX(), blockPos.getY(), blockPos.getZ());
+		
+		try {
+			UUID uuid = mod.getUUIDForWorld(world);
+			eventListeners.forEach(e -> e.onBlockChange(uuid, position));
+		} catch (IOException e) {
+			Logger.global.logError("Failed to get UUID for world: " + world, e);
+		}
+	}
+	
+	public void onWorldSave(ServerWorld world) {
+		try {
+			UUID uuid = mod.getUUIDForWorld(world);
+			eventListeners.forEach(e -> e.onWorldSaveToDisk(uuid));
+		} catch (IOException e) {
+			Logger.global.logError("Failed to get UUID for world: " + world, e);
+		}
+	}
+	
+	public void onChunkFinalize(ServerWorld world, Vector2i chunkPos) {
+		try {
+			UUID uuid = mod.getUUIDForWorld(world);
+			eventListeners.forEach(e -> e.onChunkFinishedGeneration(uuid, chunkPos));
+		} catch (IOException e) {
+			Logger.global.logError("Failed to get UUID for world: " + world, e);
+		}
+	}
+	
+}

BlueMapFabric/src/main/java/de/bluecolored/bluemap/fabric/FabricMod.java

@@ -2,62 +2,125 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutionException;
 
 import org.apache.logging.log4j.LogManager;
 
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+
 import de.bluecolored.bluemap.common.plugin.Plugin;
 import de.bluecolored.bluemap.common.plugin.commands.Commands;
 import de.bluecolored.bluemap.common.plugin.serverinterface.ServerEventListener;
 import de.bluecolored.bluemap.common.plugin.serverinterface.ServerInterface;
 import de.bluecolored.bluemap.core.logger.Logger;
+import de.bluecolored.bluemap.core.resourcepack.ParseResourceException;
 import net.fabricmc.api.ModInitializer;
+import net.fabricmc.fabric.api.event.server.ServerStartCallback;
+import net.fabricmc.fabric.api.event.server.ServerStopCallback;
 import net.fabricmc.fabric.api.registry.CommandRegistry;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.world.ServerWorld;
 
 public class FabricMod implements ModInitializer, ServerInterface {
+
+	private Plugin pluginInstance = null;
 	
-	private Plugin plugin;
+	private Map<File, UUID> worldUuids;
+	private FabricEventForwarder eventForwarder;
+	
+	private LoadingCache<ServerWorld, UUID> worldUuidCache;
+	
+	public FabricMod() {
+		Logger.global = new Log4jLogger(LogManager.getLogger(Plugin.PLUGIN_NAME));
+		
+		pluginInstance = new Plugin("fabric", this);
+		
+		this.worldUuids = new ConcurrentHashMap<>();
+		this.eventForwarder = new FabricEventForwarder(this);
+		this.worldUuidCache = CacheBuilder.newBuilder()
+				.weakKeys()
+				.maximumSize(1000)
+				.build(new CacheLoader<ServerWorld, UUID>() {
+					@Override
+					public UUID load(ServerWorld key) throws Exception {
+						return loadUUIDForWorld(key);
+					}
+				});
+	}
 	
 	@Override
 	public void onInitialize() {
-		Logger.global = new Log4jLogger(LogManager.getLogger(Plugin.PLUGIN_NAME));
-		
-		this.plugin = new Plugin("forge", this);
 		
 		//register commands
 		CommandRegistry.INSTANCE.register(true, dispatcher -> {
-			new Commands<>(plugin, dispatcher, fabricSource -> new FabricCommandSource(this, plugin, fabricSource));
+			new Commands<>(pluginInstance, dispatcher, fabricSource -> new FabricCommandSource(this, pluginInstance, fabricSource));
+		});
+		
+		ServerStartCallback.EVENT.register((MinecraftServer server) -> {
+			new Thread(()->{
+				Logger.global.logInfo("Loading BlueMap...");
+				
+				try {
+					pluginInstance.load();
+					Logger.global.logInfo("BlueMap loaded!");
+				} catch (IOException | ParseResourceException e) {
+					Logger.global.logError("Failed to load bluemap!", e);
+				}
+			}).start();
+		});
+		
+		ServerStopCallback.EVENT.register((MinecraftServer server) -> {
+			pluginInstance.unload();
+			Logger.global.logInfo("BlueMap unloaded!");
 		});
 	}
 	
-	public UUID getUUIDForWorld(ServerWorld world) throws IOException {
-		// TODO Auto-generated method stub
-		throw new UnsupportedOperationException("Not implemented!");
-	}
-
 	@Override
 	public void registerListener(ServerEventListener listener) {
-		// TODO Auto-generated method stub
-		throw new UnsupportedOperationException("Not implemented!");
+		eventForwarder.addEventListener(listener);
 	}
 
 	@Override
 	public void unregisterAllListeners() {
-		// TODO Auto-generated method stub
-		throw new UnsupportedOperationException("Not implemented!");
+		eventForwarder.removeAllListeners();
 	}
 
 	@Override
 	public UUID getUUIDForWorld(File worldFolder) throws IOException {
-		// TODO Auto-generated method stub
-		throw new UnsupportedOperationException("Not implemented!");
+		worldFolder = worldFolder.getCanonicalFile();
+		
+		UUID uuid = worldUuids.get(worldFolder);
+		if (uuid == null) {
+			uuid = UUID.randomUUID();
+			worldUuids.put(worldFolder, uuid);
+		}
+		
+		return uuid;
+	}
+
+	public UUID getUUIDForWorld(ServerWorld world) throws IOException {
+		try {
+			return worldUuidCache.get(world);
+		} catch (ExecutionException e) {
+			Throwable cause = e.getCause();
+			if (cause instanceof IOException) throw (IOException) cause;
+			else throw new IOException(cause);
+		}
+	}
+
+	private UUID loadUUIDForWorld(ServerWorld world) throws IOException {
+		File dimensionDir = world.getDimension().getType().getSaveDirectory(world.getSaveHandler().getWorldDir());
+		return getUUIDForWorld(dimensionDir);
 	}
 
 	@Override
 	public File getConfigFolder() {
-		// TODO Auto-generated method stub
-		throw new UnsupportedOperationException("Not implemented!");
+		return new File("config/bluemap");
 	}
 	
 }

BlueMapFabric/src/main/java/de/bluecolored/bluemap/fabric/events/ChunkFinalizeCallback.java

@@ -0,0 +1,19 @@
+package de.bluecolored.bluemap.fabric.events;
+
+import com.flowpowered.math.vector.Vector2i;
+
+import net.fabricmc.fabric.api.event.Event;
+import net.fabricmc.fabric.api.event.EventFactory;
+import net.minecraft.server.world.ServerWorld;
+
+public interface ChunkFinalizeCallback {
+	Event<ChunkFinalizeCallback> EVENT = EventFactory.createArrayBacked(ChunkFinalizeCallback.class,
+			(listeners) -> (world, chunkPos) -> {
+				for (ChunkFinalizeCallback event : listeners) {
+					event.onChunkFinalized(world, chunkPos);
+				}
+			}
+	);
+
+	void onChunkFinalized(ServerWorld world, Vector2i chunkPos);
+}

BlueMapFabric/src/main/java/de/bluecolored/bluemap/fabric/events/WorldSaveCallback.java

@@ -0,0 +1,17 @@
+package de.bluecolored.bluemap.fabric.events;
+
+import net.fabricmc.fabric.api.event.Event;
+import net.fabricmc.fabric.api.event.EventFactory;
+import net.minecraft.server.world.ServerWorld;
+
+public interface WorldSaveCallback {
+	Event<WorldSaveCallback> EVENT = EventFactory.createArrayBacked(WorldSaveCallback.class,
+			(listeners) -> (world) -> {
+				for (WorldSaveCallback event : listeners) {
+					event.onWorldSaved(world);
+				}
+			}
+	);
+
+	void onWorldSaved(ServerWorld world);
+}

BlueMapFabric/src/main/java/de/bluecolored/bluemap/fabric/mixin/MixinChunkGenerator.java

@@ -0,0 +1,32 @@
+package de.bluecolored.bluemap.fabric.mixin;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.flowpowered.math.vector.Vector2i;
+
+import de.bluecolored.bluemap.fabric.events.ChunkFinalizeCallback;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.world.ChunkRegion;
+import net.minecraft.world.IWorld;
+import net.minecraft.world.gen.chunk.ChunkGenerator;
+
+@Mixin(ChunkGenerator.class)
+public class MixinChunkGenerator {
+
+	@Shadow
+	@Final
+	protected IWorld world;
+	
+	@Inject(at = @At("RETURN"), method = "generateFeatures")
+	public void generateFeatures(ChunkRegion region, CallbackInfo ci) {
+		if (world instanceof ServerWorld) {
+			ChunkFinalizeCallback.EVENT.invoker().onChunkFinalized((ServerWorld) world, new Vector2i(region.getCenterChunkX(), region.getCenterChunkZ()));
+		}
+	}
+	
+}

BlueMapFabric/src/main/java/de/bluecolored/bluemap/fabric/mixin/MixinServerWorld.java

@@ -0,0 +1,21 @@
+package de.bluecolored.bluemap.fabric.mixin;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import de.bluecolored.bluemap.fabric.events.WorldSaveCallback;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.ProgressListener;
+import net.minecraft.world.SessionLockException;
+
+@Mixin(ServerWorld.class)
+public abstract class MixinServerWorld {
+
+	@Inject(at = @At("RETURN"), method = "save")
+	public void save(ProgressListener progressListener, boolean flush, boolean bl, CallbackInfo ci) throws SessionLockException {		
+		WorldSaveCallback.EVENT.invoker().onWorldSaved((ServerWorld) (Object) this);
+	}
+	
+}

BlueMapFabric/src/main/resources/bluemap-fabric-defaults.conf

@@ -0,0 +1,11 @@
+accept-download: false
+metrics: true
+renderThreadCount: -2
+data: "bluemap"
+webroot: "bluemap/web"
+useCookies: true
+webserver {
+	enabled: true
+	port: 8100
+	maxConnectionCount: 100
+}

BlueMapFabric/src/main/resources/bluemap-fabric.conf

@@ -0,0 +1,166 @@
+##                          ##
+##         BlueMap          ##
+##                          ##
+##  by Blue (Lukas Rieger)  ##
+##  http://bluecolored.de/  ##
+##                          ##
+
+# By changing the setting (accept-download) below to TRUE you are indicating that you have accepted mojang's EULA (https://account.mojang.com/documents/minecraft_eula),
+# you confirm that you own a license to Minecraft (Java Edition)
+# and you agree that BlueMap will download and use this file for you: %minecraft-client-url%
+# (Alternatively you can download the file yourself and store it here: <data>/minecraft-client-%minecraft-client-version%.jar)
+# This file contains resources that belong to mojang and you must not redistribute it or do anything else that is not compliant with mojang's EULA.
+# BlueMap uses resources in this file to generate the 3D-Models used for the map and texture them. (BlueMap will not work without those resources.)
+# %datetime-iso%
+accept-download: false
+
+# This changes the amount of threads that BlueMap will use to render the maps.
+# A higher value can improve render-speed but could impact performance on the host machine.
+# This should be always below or equal to the number of available processor-cores.
+# Zero or a negative value means the amount of of available processor-cores subtracted by the value.
+# (So a value of -2 with 6 cores results in 4 render-processes)
+# Default is -2
+renderThreadCount: -2
+
+# If this is true, BlueMap might send really basic metrics reports containg only the implementation-type and the version that is being used to https://metrics.bluecolored.de/bluemap/
+# This allows me to track the basic usage of BlueMap and helps me stay motivated to further develop this tool! Please leave it on :)
+# An example report looks like this: {"implementation":"forge","version":"%version%"}
+metrics: true
+
+# The folder where bluemap saves data-files it needs during runtime or to save e.g. the render-progress to resume it later.
+data: "bluemap"
+
+# The webroot of the website that displays the map.
+webroot: "bluemap/web"
+
+# Unncomment this to override the path where bluemap stores the data-files.
+# Default is "<webroot>/data"
+#webdata: "path/to/data/folder"
+
+# If the web-application should use cookies to save the configurations of a user.
+useCookies: true
+
+webserver {
+	# With this setting you can disable the integrated web-server.
+	# This is usefull if you want to only render the map-data for later use, or if you setup your own webserver.
+	# Default is enabled
+	enabled: true
+
+	# The IP-Adress that the webserver binds to.
+	# If this setting is commented out, bluemap tries to find the default ip-adress of your system.
+	# If you only want to access it locally use "localhost".
+	#ip: "localhost"
+	#ip: "127.0.0.1"
+
+	# The port that the webserver listenes to.
+	# Default is 8100
+	port: 8100
+
+	# Max number of simultaneous connections that the webserver allows
+	# Default is 100
+	maxConnectionCount: 100
+}
+
+# This is an array with multiple configured maps.
+# You can define multiple maps, for different worlds with different render-settings here
+maps: [
+
+	{
+		# The id of this map
+		# Should only contain word-charactes: [a-zA-Z0-9_]
+		# Changing this value breaks your existing renders.
+		id: "world"
+	
+		# The name of this map
+		# This defines the display name of this map, you can change this at any time.
+		# Default is the id of this map
+		name: "World"
+		
+		# The path to the save-folder of the world to render.
+		world: "world"
+		
+		# The position on the world where the map will be centered if you open it.
+		# You can change this at any time.
+		# This defaults to the world-spawn if you don't set it.
+		#startPos: [500, -820]
+		
+		# The color of thy sky as a hex-color
+		# You can change this at any time.
+		# Default is "#7dabff"
+		skyColor: "#7dabff"
+
+		# Defines the ambient light-strength that every block is recieving, regardless of the sunlight/blocklight.
+		# 0 is no ambient light, 1 is fully lighted.
+		# You can change this at any time.
+		# Default is 0
+		ambientLight: 0
+
+		# If this is false, BlueMap tries to omit all blocks that are not visible from above-ground.
+		# More specific: Block-Faces that have a sunlight/skylight value of 0 are removed.
+		# This improves the performance of the map on slower devices by a lot, but might cause some blocks to disappear that should normally be visible.
+		# Changing this value requires a re-render of the map.
+		# Default is false
+		renderCaves: false
+		
+		# With the below values you can limit the map-render.
+		# This can be used to ignore the nethers ceiling or render only a certain part of a world.
+		# Changing this values might require a re-render of the map, already rendered tiles outside the limits will not be deleted.
+		# Default is no min or max value (= infinite bounds)
+		#minX: -4000
+		#maxX: 4000
+		#minZ: -4000
+		#maxZ: 4000
+		#minY: 50
+		#maxY: 126
+				
+		# Using this, BlueMap pretends that every Block out of the defined render-bounds is AIR,
+		# this means you can see the blocks where the world is cut (instead of having a see-through/xray view).
+		# This has only an effect if you set some render-bounds above.
+		# Changing this value requires a re-render of the map.
+		# Default is true
+		renderEdges: true
+		
+		# With this set to true, the generated files for this world are compressed using gzip to save A LOT of space.
+		# Files will be only 5% as big with compression!
+		# Note: If you are using NGINX or Apache to host your map, you can configure them to serve the compressed files directly.
+		# This is much better than disabling the compression.
+		# Changing this value requires a re-render of the map.
+		# Default is true
+		useCompression: true
+	}
+	
+	# Here another example for the End-Map
+	# Things we don't want to change from default we can just omit
+	{
+		id: "end"
+		name: "End"
+		world: "world/DIM1"
+		
+		# We dont want a blue sky in the end
+		skyColor: "#080010"
+		
+		# In the end is no sky-light, so we need to enable this or we won't see anything.
+		renderCaves: true
+		
+		# Same here, we don't want a dark map. But not completely lighted, so we see the effect of e.g torches.
+		ambientLight: 0.6
+	}
+	
+	# Here another example for the Nether-Map
+	{
+		id: "nether"
+		name: "Nether"
+		world: "world/DIM-1"
+		
+		skyColor: "#290000"
+		
+		renderCaves: true
+		ambientLight: 0.6
+		
+		# We slice the whole world at y:90 so every block above 90 will be air.
+		# This way we don't render the nethers ceiling.
+		maxY: 90
+		renderEdges: true
+	}
+
+]

BlueMapFabric/src/main/resources/bluemap.mixins.json

@@ -1,13 +1,15 @@
 {
-  "required": true,
-  "minVersion": "0.8",
-  "package": "de.bluecolored.bluemap.fabric.mixin",
-  "compatibilityLevel": "JAVA_8",
-  "mixins": [
-  ],
-  "client": [
-  ],
-  "injectors": {
-    "defaultRequire": 1
-  }
-}
+	"required": true,
+	"minVersion": "0.8",
+	"package": "de.bluecolored.bluemap.fabric.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [],
+	"client": [],
+	"server": [
+		"MixinServerWorld",
+		"MixinChunkGenerator"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}

BlueMapForge/src/main/java/de/bluecolored/bluemap/forge/ForgeMod.java

@@ -31,10 +31,14 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.ExecutionException;
 
 import org.apache.logging.log4j.LogManager;
 
 import com.flowpowered.math.vector.Vector3i;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
 
 import de.bluecolored.bluemap.common.plugin.Plugin;
 import de.bluecolored.bluemap.common.plugin.commands.Commands;
@@ -59,12 +63,23 @@ public class ForgeMod implements ServerInterface {
 	private Map<String, UUID> worldUUIDs;
 	private Collection<ServerEventListener> eventListeners;
 	
+	private LoadingCache<ServerWorld, UUID> worldUuidCache;
+	
 	public ForgeMod() {
 		Logger.global = new Log4jLogger(LogManager.getLogger(Plugin.PLUGIN_NAME));
 		
 		this.bluemap = new Plugin("forge", this);
 		this.worldUUIDs = new HashMap<>();
 		this.eventListeners = new ArrayList<>(1);
+		this.worldUuidCache = CacheBuilder.newBuilder()
+				.weakKeys()
+				.maximumSize(1000)
+				.build(new CacheLoader<ServerWorld, UUID>() {
+					@Override
+					public UUID load(ServerWorld key) throws Exception {
+						return loadUUIDForWorld(key);
+					}
+				});
 		
 		MinecraftForge.EVENT_BUS.register(this);
 	}
@@ -175,6 +190,16 @@ public UUID getUUIDForWorld(File worldFolder) throws IOException {
 	}
 	
 	public UUID getUUIDForWorld(ServerWorld world) throws IOException {
+		try {
+			return worldUuidCache.get(world);
+		} catch (ExecutionException e) {
+			Throwable cause = e.getCause();
+			if (cause instanceof IOException) throw (IOException) cause;
+			else throw new IOException(cause);
+		}
+	}
+	
+	private UUID loadUUIDForWorld(ServerWorld world) throws IOException {
 		synchronized (worldUUIDs) {
 			String key = getFolderForWorld(world).getPath();