Better Location code for lazy loading worlds

This fixes problems with worlds that are loaded after the Location object is created and should prevent memory leaks when a world is unloaded.

Essentials/src/com/earth2me/essentials/Essentials.java

@@ -19,6 +19,7 @@ package com.earth2me.essentials;
 
 import static com.earth2me.essentials.I18n._;
 import com.earth2me.essentials.api.*;
+import com.earth2me.essentials.craftbukkit.BetterLocation;
 import com.earth2me.essentials.craftbukkit.ItemDupeFix;
 import com.earth2me.essentials.listener.*;
 import com.earth2me.essentials.perm.PermissionsHandler;
@@ -230,6 +231,10 @@ public class Essentials extends JavaPlugin implements IEssentials
 		reloadList.add(jails);
 
 		pm.registerEvent(Type.ENTITY_EXPLODE, tntListener, Priority.High, this);
+		
+		pm.registerEvent(Type.WORLD_LOAD, BetterLocation.getListener(), Priority.Monitor, this);
+		pm.registerEvent(Type.WORLD_UNLOAD, BetterLocation.getListener(), Priority.Monitor, this);
+		getServer().getScheduler().scheduleAsyncRepeatingTask(this, BetterLocation.getListener(), 200, 200);
 
 		final EssentialsTimer timer = new EssentialsTimer(this);
 		getServer().getScheduler().scheduleSyncRepeatingTask(this, timer, 1, 100);
@@ -249,6 +254,7 @@ public class Essentials extends JavaPlugin implements IEssentials
 		i18n.onDisable();
 		Economy.setEss(null);
 		Trade.closeLog();
+		BetterLocation.cleanup();
 	}
 
 	@Override

Essentials/src/com/earth2me/essentials/craftbukkit/BetterLocation.java

@@ -0,0 +1,254 @@
+package com.earth2me.essentials.craftbukkit;
+
+import java.lang.ref.WeakReference;
+import java.util.*;
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.event.world.WorldLoadEvent;
+import org.bukkit.event.world.WorldUnloadEvent;
+
+
+public class BetterLocation extends Location
+{
+	private transient String worldName;
+	private static BetterLocationListener listener = new BetterLocationListener();
+
+	public static BetterLocationListener getListener()
+	{
+		return listener;
+	}
+
+	public static void cleanup()
+	{
+		synchronized (listener.locationMap)
+		{
+			listener.locationMap.clear();
+		}
+	}
+
+	public BetterLocation(final String worldName, final double x, final double y, final double z)
+	{
+		super(Bukkit.getWorld(worldName), x, y, z);
+		this.worldName = worldName;
+		addToMap(this);
+	}
+
+	public BetterLocation(final String worldName, final double x, final double y,
+						  final double z, final float yaw, final float pitch)
+	{
+		super(Bukkit.getWorld(worldName), x, y, z, yaw, pitch);
+		this.worldName = worldName;
+		addToMap(this);
+	}
+
+	public BetterLocation(final World world, final double x, final double y, final double z)
+	{
+		super(world, x, y, z);
+		if (world == null)
+		{
+			throw new WorldNotLoadedException();
+		}
+		this.worldName = world.getName();
+		addToMap(this);
+	}
+
+	public BetterLocation(final World world, final double x, final double y,
+						  final double z, final float yaw, final float pitch)
+	{
+		super(world, x, y, z, yaw, pitch);
+		if (world == null)
+		{
+			throw new WorldNotLoadedException();
+		}
+		this.worldName = world.getName();
+		addToMap(this);
+	}
+
+	public BetterLocation(final Location location)
+	{
+		super(location.getWorld(), location.getX(), location.getY(), location.getZ(), location.getYaw(), location.getPitch());
+		if (location.getWorld() == null)
+		{
+			throw new WorldNotLoadedException();
+		}
+		this.worldName = location.getWorld().getName();
+		addToMap(this);
+	}
+
+	@Override
+	public World getWorld()
+	{
+		World world = super.getWorld();
+		if (world == null)
+		{
+			world = Bukkit.getWorld(worldName);
+		}
+		if (world == null)
+		{
+			throw new WorldNotLoadedException();
+		}
+		else
+		{
+			super.setWorld(world);
+		}
+		return world;
+	}
+
+	@Override
+	public void setWorld(final World world)
+	{
+		if (world == null)
+		{
+			throw new WorldNotLoadedException();
+		}
+		if (!world.getName().equals(this.worldName))
+		{
+			getListener().removeLocation(this);
+			this.worldName = world.getName();
+			addToMap(this);
+		}
+		super.setWorld(world);
+	}
+
+	public String getWorldName()
+	{
+		return worldName;
+	}
+
+	private void addToMap(final BetterLocation location)
+	{
+		synchronized (listener.locationMap)
+		{
+			List<WeakReference<Location>> locations = listener.locationMap.get(location.getWorldName());
+			if (locations == null)
+			{
+				locations = new LinkedList<WeakReference<Location>>();
+				listener.locationMap.put(location.getWorldName(), locations);
+			}
+			locations.add(new WeakReference<Location>(location));
+		}
+	}
+
+
+	public static class WorldNotLoadedException extends RuntimeException
+	{
+		public WorldNotLoadedException()
+		{
+			super("World is not loaded.");
+		}
+	}
+
+
+	public static class BetterLocationListener extends org.bukkit.event.world.WorldListener implements Runnable
+	{
+		private static Random random = new Random();
+		private final transient Map<String, List<WeakReference<Location>>> locationMap = new HashMap<String, List<WeakReference<Location>>>();
+
+		@Override
+		public void onWorldLoad(final WorldLoadEvent event)
+		{
+			final String worldName = event.getWorld().getName();
+			synchronized (locationMap)
+			{
+				final List<WeakReference<Location>> locations = locationMap.get(worldName);
+				if (locations != null)
+				{
+					for (final Iterator<WeakReference<Location>> it = locations.iterator(); it.hasNext();)
+					{
+						final WeakReference<Location> weakReference = it.next();
+						final Location loc = weakReference.get();
+						if (loc == null)
+						{
+							it.remove();
+						}
+						else
+						{
+							loc.setWorld(event.getWorld());
+						}
+					}
+				}
+			}
+		}
+
+		@Override
+		public void onWorldUnload(final WorldUnloadEvent event)
+		{
+			final String worldName = event.getWorld().getName();
+			synchronized (locationMap)
+			{
+				final List<WeakReference<Location>> locations = locationMap.get(worldName);
+				if (locations != null)
+				{
+					for (final Iterator<WeakReference<Location>> it = locations.iterator(); it.hasNext();)
+					{
+						final WeakReference<Location> weakReference = it.next();
+						final Location loc = weakReference.get();
+						if (loc == null)
+						{
+							it.remove();
+						}
+						else
+						{
+							loc.setWorld(null);
+						}
+					}
+				}
+			}
+		}
+
+		@Override
+		public void run()
+		{
+			synchronized (locationMap)
+			{
+				// Pick a world by random
+				final Collection<List<WeakReference<Location>>> allWorlds = locationMap.values();
+				final int randomPick = (allWorlds.isEmpty() ? 0 : random.nextInt(allWorlds.size()));
+				List<WeakReference<Location>> locations = null;
+				final Iterator<List<WeakReference<Location>>> iterator = allWorlds.iterator();
+				for (int i = 0; iterator.hasNext() && i < randomPick; i++)
+				{
+					iterator.next();
+				}
+				if (iterator.hasNext())
+				{
+					locations = iterator.next();
+				}
+				if (locations != null)
+				{
+					for (final Iterator<WeakReference<Location>> it = locations.iterator(); it.hasNext();)
+					{
+						final WeakReference<Location> weakReference = it.next();
+						final Location loc = weakReference.get();
+						if (loc == null)
+						{
+							it.remove();
+						}
+					}
+				}
+			}
+		}
+
+		private void removeLocation(final BetterLocation location)
+		{
+			final String worldName = location.getWorldName();
+			synchronized (locationMap)
+			{
+				final List<WeakReference<Location>> locations = locationMap.get(worldName);
+				if (locations != null)
+				{
+					for (final Iterator<WeakReference<Location>> it = locations.iterator(); it.hasNext();)
+					{
+						final WeakReference<Location> weakReference = it.next();
+						final Location loc = weakReference.get();
+						if (loc == null || loc == location)
+						{
+							it.remove();
+						}
+					}
+				}
+			}
+		}
+	}
+}

Essentials/src/com/earth2me/essentials/craftbukkit/OfflineBedLocation.java

@@ -38,7 +38,7 @@ public class OfflineBedLocation
 				{
 					spawnWorld = cserver.getWorlds().get(0).getName();
 				}
-				return new Location(cserver.getWorld(spawnWorld), playerStorage.getInt("SpawnX"), playerStorage.getInt("SpawnY"), playerStorage.getInt("SpawnZ"));
+				return new BetterLocation(spawnWorld, playerStorage.getInt("SpawnX"), playerStorage.getInt("SpawnY"), playerStorage.getInt("SpawnZ"));
 			}
 			return null;
 		}

Essentials/src/com/earth2me/essentials/storage/BukkitConstructor.java

@@ -1,15 +1,14 @@
 package com.earth2me.essentials.storage;
 
 import com.earth2me.essentials.Essentials;
+import com.earth2me.essentials.craftbukkit.BetterLocation;
 import java.lang.reflect.Field;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.regex.Pattern;
-import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.Material;
-import org.bukkit.World;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.material.MaterialData;
@@ -281,12 +280,7 @@ public class BukkitConstructor extends Constructor
 				{
 					return null;
 				}
-				final World world = Bukkit.getWorld(worldName);
-				if (world == null)
-				{
-					return null;
-				}
-				return new Location(world, x, y, z, yaw, pitch);
+				return new BetterLocation(worldName, x, y, z, yaw, pitch);
 			}
 			return super.construct(node);
 		}

Essentials/src/com/earth2me/essentials/storage/YamlStorageWriter.java

@@ -1,5 +1,6 @@
 package com.earth2me.essentials.storage;
 
+import com.earth2me.essentials.craftbukkit.BetterLocation;
 import java.io.PrintWriter;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -24,12 +25,12 @@ public class YamlStorageWriter implements IStorageWriter
 	private transient static final Pattern NON_WORD_PATTERN = Pattern.compile("\\W");
 	private transient final PrintWriter writer;
 	private transient static final Yaml YAML = new Yaml();
-
+	
 	public YamlStorageWriter(final PrintWriter writer)
 	{
 		this.writer = writer;
 	}
-
+	
 	@Override
 	public void save(final StorageObject object)
 	{
@@ -46,7 +47,7 @@ public class YamlStorageWriter implements IStorageWriter
 			Logger.getLogger(YamlStorageWriter.class.getName()).log(Level.SEVERE, null, ex);
 		}
 	}
-
+	
 	private void writeToFile(final Object object, final int depth, final Class clazz) throws IllegalAccessException
 	{
 		for (Field field : clazz.getDeclaredFields())
@@ -55,7 +56,7 @@ public class YamlStorageWriter implements IStorageWriter
 			if (Modifier.isPrivate(modifier) && !Modifier.isTransient(modifier) && !Modifier.isStatic(modifier))
 			{
 				field.setAccessible(true);
-
+				
 				final Object data = field.get(object);
 				if (writeKey(field, depth, data))
 				{
@@ -86,7 +87,7 @@ public class YamlStorageWriter implements IStorageWriter
 			}
 		}
 	}
-
+	
 	private boolean writeKey(final Field field, final int depth, final Object data)
 	{
 		final boolean commentPresent = writeComment(field, depth);
@@ -110,7 +111,7 @@ public class YamlStorageWriter implements IStorageWriter
 		}
 		return false;
 	}
-
+	
 	private boolean writeComment(final Field field, final int depth)
 	{
 		final boolean commentPresent = field.isAnnotationPresent(Comment.class);
@@ -132,7 +133,7 @@ public class YamlStorageWriter implements IStorageWriter
 		}
 		return commentPresent;
 	}
-
+	
 	private void writeCollection(final Collection<Object> data, final int depth) throws IllegalAccessException
 	{
 		writer.println();
@@ -163,7 +164,7 @@ public class YamlStorageWriter implements IStorageWriter
 		}
 		writer.println();
 	}
-
+	
 	private void writeMap(final Map<Object, Object> data, final int depth) throws IllegalArgumentException, IllegalAccessException
 	{
 		writer.println();
@@ -200,7 +201,7 @@ public class YamlStorageWriter implements IStorageWriter
 			}
 		}
 	}
-
+	
 	private void writeIndention(final int depth)
 	{
 		for (int i = 0; i < depth; i++)
@@ -208,7 +209,7 @@ public class YamlStorageWriter implements IStorageWriter
 			writer.print("  ");
 		}
 	}
-
+	
 	private void writeScalar(final Object data)
 	{
 		if (data instanceof String || data instanceof Boolean || data instanceof Number)
@@ -248,7 +249,7 @@ public class YamlStorageWriter implements IStorageWriter
 			throw new UnsupportedOperationException();
 		}
 	}
-
+	
 	private void writeKey(final Object data)
 	{
 		if (data instanceof String || data instanceof Boolean || data instanceof Number)
@@ -286,12 +287,12 @@ public class YamlStorageWriter implements IStorageWriter
 			throw new UnsupportedOperationException();
 		}
 	}
-
+	
 	private void writeMaterial(final Object data)
 	{
 		writer.print(data.toString().toLowerCase(Locale.ENGLISH));
 	}
-
+	
 	private void writeMaterialData(final Object data)
 	{
 		final MaterialData matData = (MaterialData)data;
@@ -302,7 +303,7 @@ public class YamlStorageWriter implements IStorageWriter
 			writer.print(matData.getData());
 		}
 	}
-
+	
 	private void writeItemStack(final Object data)
 	{
 		final ItemStack itemStack = (ItemStack)data;
@@ -315,7 +316,7 @@ public class YamlStorageWriter implements IStorageWriter
 			writeEnchantmentLevel(entry);
 		}
 	}
-
+	
 	private void writeEnchantmentLevel(Object data)
 	{
 		final Entry<Enchantment, Integer> enchLevel = (Entry<Enchantment, Integer>)data;
@@ -323,13 +324,20 @@ public class YamlStorageWriter implements IStorageWriter
 		writer.print(':');
 		writer.print(enchLevel.getValue());
 	}
-
+	
 	private void writeLocation(final Location entry, final int depth)
 	{
 		writer.println();
 		writeIndention(depth);
 		writer.print("world: ");
-		writeScalar(entry.getWorld().getName());
+		if (entry instanceof BetterLocation)
+		{
+			writeScalar(((BetterLocation)entry).getWorldName());
+		}
+		else
+		{
+			writeScalar(entry.getWorld().getName());
+		}
 		writeIndention(depth);
 		writer.print("x: ");
 		writeScalar(entry.getX());

Essentials/src/com/earth2me/essentials/user/UserBase.java

@@ -4,6 +4,7 @@ import com.earth2me.essentials.Util;
 import com.earth2me.essentials.api.IEssentials;
 import com.earth2me.essentials.api.ISettings;
 import com.earth2me.essentials.api.InvalidNameException;
+import com.earth2me.essentials.craftbukkit.BetterLocation;
 import com.earth2me.essentials.craftbukkit.OfflineBedLocation;
 import com.earth2me.essentials.storage.AsyncStorageObjectHolder;
 import java.io.File;
@@ -31,7 +32,7 @@ public abstract class UserBase extends AsyncStorageObjectHolder<UserData> implem
 		Player.class, Entity.class, CommandSender.class, ServerOperator.class,
 		HumanEntity.class, ConfigurationSerializable.class, LivingEntity.class,
 		Permissible.class
-	}, excludes = IOfflinePlayer.class)
+	}, excludes = {IOfflinePlayer.class, OtherExcludes.class})
 	protected Player base;
 	protected transient OfflinePlayer offlinePlayer;
 
@@ -436,4 +437,14 @@ public abstract class UserBase extends AsyncStorageObjectHolder<UserData> implem
 			unlock();
 		}
 	}
+	
+	@Override
+	public Location getLocation()
+	{
+		return new BetterLocation(base.getLocation());
+	}
+	
+	public static interface OtherExcludes {
+		Location getLocation();
+	}
 }