Further alleviating the time it takes to load chunks.

src/main/java/com/gmail/nossr50/listeners/WorldListener.java

@@ -2,11 +2,16 @@ package com.gmail.nossr50.listeners;
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 import org.bukkit.Chunk;
 import org.bukkit.TreeType;
 import org.bukkit.World;
 import org.bukkit.block.BlockState;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.FallingBlock;
+import org.bukkit.entity.LivingEntity;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
@@ -76,8 +81,17 @@ public class WorldListener implements Listener {
     @EventHandler
     public void onChunkLoad(ChunkLoadEvent event) {
         Chunk chunk = event.getChunk();
-        if (chunk.getEntities().length > 0) {
+        List<Entity> chunkMobs = new ArrayList(Arrays.asList(chunk.getEntities()));
+
+        if (chunkMobs.isEmpty())
+            return;
+
+        for(Entity entity : chunkMobs) {
+            if(!(entity instanceof LivingEntity) && !(entity instanceof FallingBlock))
+                continue;
+
             mcMMO.placeStore.loadChunk(chunk.getX(), chunk.getZ(), event.getWorld());
+            return;
         }
     }
 }

src/main/java/com/gmail/nossr50/util/blockmeta/chunkmeta/HashChunkManager.java

@@ -8,6 +8,7 @@ import java.io.ObjectOutputStream;
 import java.lang.Boolean;
 import java.lang.Integer;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -161,12 +162,13 @@ public class HashChunkManager implements ChunkManager {
 
         UUID key = world.getUID();
         boolean oldDataHasKey = oldData.containsKey(key);
+	boolean converted = false;
 
         if (!oldDataHasKey) {
             oldData.put(key, (new File(world.getWorldFolder(), "mcmmo_data")).exists());
         }
         else if (oldData.get(key)) {
-            convertChunk(new File(world.getWorldFolder(), "mcmmo_data"), cx, cz, world, true);
+            converted = convertChunk(new File(world.getWorldFolder(), "mcmmo_data"), cx, cz, world, true);
         }
 
         try {
@@ -174,31 +176,32 @@ public class HashChunkManager implements ChunkManager {
         }
         catch(Exception e) {}
 
-        if (in != null) {
-            store.put(world.getName() + "," + cx + "," + cz, in);
+        if (in == null || converted)
+            return;
 
-            List<UUID> mobs = in.getSpawnedMobs();
+        store.put(world.getName() + "," + cx + "," + cz, in);
 
-            if (mobs.isEmpty())
-                return;
+        List<UUID> mobs = in.getSpawnedMobs();
 
-            iteratingMobs = true;
+        if (mobs.isEmpty())
+            return;
 
-            for (LivingEntity entity : world.getLivingEntities()) {
-                if (mobs.contains(entity.getUniqueId()))
-                    addSpawnedMob(entity);
-            }
+        iteratingMobs = true;
 
-            for(FallingBlock entity: world.getEntitiesByClass(FallingBlock.class)) {
-                if (mobs.contains(entity.getUniqueId()))
-                    addSpawnedMob(entity);
-            }
+        List<Entity> chunkMobs = new ArrayList(Arrays.asList(world.getChunkAt(cx, cz).getEntities()));
 
-            if(safeToRemoveMobs)
-                iteratingMobs = false;
+        for (Entity entity : chunkMobs) {
+            if(!(entity instanceof LivingEntity) && !(entity instanceof FallingBlock))
+                continue;
 
-            in.clearSpawnedMobs();
+            if (mobs.contains(entity.getUniqueId()))
+                addSpawnedMob(entity);
         }
+
+        if(safeToRemoveMobs)
+            iteratingMobs = false;
+
+        in.clearSpawnedMobs();
     }
 
     @Override
@@ -546,14 +549,14 @@ public class HashChunkManager implements ChunkManager {
         convertChunk(dataDir, cx, cz, world, false);
     }
 
-    public synchronized void convertChunk(File dataDir, int cx, int cz, World world, boolean actually) {
+    public synchronized boolean convertChunk(File dataDir, int cx, int cz, World world, boolean actually) {
         if (!actually)
-            return;
-        if (!dataDir.exists()) return;
+            return false;
+        if (!dataDir.exists()) return false;
         File cxDir = new File(dataDir, "" + cx);
-        if (!cxDir.exists()) return;
+        if (!cxDir.exists()) return false;
         File czDir = new File(cxDir, "" + cz);
-        if (!czDir.exists()) return;
+        if (!czDir.exists()) return false;
 
         boolean conversionSet = false;
 
@@ -574,6 +577,8 @@ public class HashChunkManager implements ChunkManager {
             converter.start(world, cxDir, czDir);
             converters.add(converter);
         }
+
+	return true;
     }
 
     public boolean isSpawnedMob(Entity entity) {