Clean up some dimension manager code and add a command to list dimensions (#4902)

src/main/java/net/minecraftforge/common/DimensionManager.java

@@ -24,17 +24,22 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Hashtable;
+import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.concurrent.ConcurrentMap;
 
-import it.unimi.dsi.fastutil.ints.IntArrayList;
-import it.unimi.dsi.fastutil.ints.IntListIterator;
+import it.unimi.dsi.fastutil.ints.Int2ObjectLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMaps;
+import it.unimi.dsi.fastutil.ints.IntIterator;
+import it.unimi.dsi.fastutil.ints.IntLinkedOpenHashSet;
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntRBTreeSet;
 import it.unimi.dsi.fastutil.ints.IntSet;
 import it.unimi.dsi.fastutil.ints.IntSets;
+import it.unimi.dsi.fastutil.ints.IntSortedSet;
 
 import com.google.common.collect.HashMultiset;
 import com.google.common.collect.Lists;
@@ -71,10 +76,10 @@ public class DimensionManager
 
     private static boolean hasInit = false;
 
-    private static final Hashtable<Integer, WorldServer> worlds = new Hashtable<>();
-    private static final Hashtable<Integer, Dimension> dimensions = new Hashtable<>();
+    private static final Int2ObjectMap<WorldServer> worlds = Int2ObjectMaps.synchronize(new Int2ObjectLinkedOpenHashMap<>());
+    private static final Int2ObjectMap<Dimension> dimensions = Int2ObjectMaps.synchronize(new Int2ObjectLinkedOpenHashMap<>());
     private static final IntSet keepLoaded = IntSets.synchronize(new IntOpenHashSet());
-    private static final IntArrayList unloadQueue = new IntArrayList();
+    private static final IntSet unloadQueue = IntSets.synchronize(new IntLinkedOpenHashSet());
     private static final BitSet dimensionMap = new BitSet(Long.SIZE << 4);
     private static final ConcurrentMap<World, World> weakWorldMap = new MapMaker().weakKeys().weakValues().makeMap();
     private static final Multiset<Integer> leakedWorlds = HashMultiset.create();
@@ -86,17 +91,27 @@ public class DimensionManager
     {
         int[] ret = new int[dimensions.size()];
         int x = 0;
-        for (Map.Entry<Integer, Dimension> ent : dimensions.entrySet())
+        for (Int2ObjectMap.Entry<Dimension> ent : dimensions.int2ObjectEntrySet())
         {
             if (ent.getValue().type == type)
             {
-                ret[x++] = ent.getKey();
+                ret[x++] = ent.getIntKey();
             }
         }
 
         return Arrays.copyOf(ret, x);
     }
 
+    public static Map<DimensionType, IntSortedSet> getRegisteredDimensions()
+    {
+        Map<DimensionType, IntSortedSet> map = new IdentityHashMap<>();
+        for (Int2ObjectMap.Entry<Dimension> entry : dimensions.int2ObjectEntrySet())
+        {
+            map.computeIfAbsent(entry.getValue().type, k -> new IntRBTreeSet()).add(entry.getIntKey());
+        }
+        return map;
+    }
+
     public static void init()
     {
         if (hasInit)
@@ -182,9 +197,10 @@ public class DimensionManager
         }
         return getIDs();
     }
+
     public static Integer[] getIDs()
     {
-        return worlds.keySet().toArray(new Integer[worlds.size()]); //Only loaded dims, since usually used to cycle through loaded worlds
+        return worlds.keySet().toArray(new Integer[0]); // Only loaded dims, since usually used to cycle through loaded worlds
     }
 
     public static void setWorld(int id, @Nullable WorldServer world, MinecraftServer server)
@@ -211,9 +227,9 @@ public class DimensionManager
         if (worlds.get( 1) != null)
             tmp.add(worlds.get( 1));
 
-        for (Entry<Integer, WorldServer> entry : worlds.entrySet())
+        for (Int2ObjectMap.Entry<WorldServer> entry : worlds.int2ObjectEntrySet())
         {
-            int dim = entry.getKey();
+            int dim = entry.getIntKey();
             if (dim >= -1 && dim <= 1)
             {
                 continue;
@@ -221,7 +237,7 @@ public class DimensionManager
             tmp.add(entry.getValue());
         }
 
-        server.worlds = tmp.toArray(new WorldServer[tmp.size()]);
+        server.worlds = tmp.toArray(new WorldServer[0]);
     }
 
     public static void initDimension(int dim)
@@ -257,12 +273,21 @@ public class DimensionManager
 
     public static WorldServer getWorld(int id)
     {
+        return getWorld(id, false);
+    }
+
+    public static WorldServer getWorld(int id, boolean resetUnloadDelay)
+    {
+        if (resetUnloadDelay && unloadQueue.contains(id))
+        {
+            dimensions.get(id).ticksWaited = 0;
+        }
         return worlds.get(id);
     }
 
     public static WorldServer[] getWorlds()
     {
-        return worlds.values().toArray(new WorldServer[worlds.size()]);
+        return worlds.values().toArray(new WorldServer[0]);
     }
 
     static
@@ -276,8 +301,9 @@ public class DimensionManager
      */
     public static Integer[] getStaticDimensionIDs()
     {
-        return dimensions.keySet().toArray(new Integer[dimensions.keySet().size()]);
+        return dimensions.keySet().toArray(new Integer[0]);
     }
+
     public static WorldProvider createProviderFor(int dim)
     {
         try
@@ -322,7 +348,6 @@ public class DimensionManager
 
     /**
      * Queues a dimension to unload, if it can be unloaded.
-     * If the dimension is already queued, it will reset the delay to unload.
      * @param id The id of the dimension
      */
     public static void unloadWorld(int id)
@@ -330,14 +355,9 @@ public class DimensionManager
         WorldServer world = worlds.get(id);
         if (world == null || !canUnloadWorld(world)) return;
 
-        if (!unloadQueue.contains(id))
+        if (unloadQueue.add(id))
         {
             FMLLog.log.debug("Queueing dimension {} to unload", id);
-            unloadQueue.add(id);
-        }
-        else
-        {
-            dimensions.get(id).ticksWaited = 0;
         }
     }
 
@@ -347,12 +367,14 @@ public class DimensionManager
     }
 
     /*
-    * To be called by the server at the appropriate time, do not call from mod code.
-    */
-    public static void unloadWorlds(Hashtable<Integer, long[]> worldTickTimes) {
-        IntListIterator queueIterator = unloadQueue.iterator();
-        while (queueIterator.hasNext()) {
-            int id = queueIterator.next();
+     * To be called by the server at the appropriate time, do not call from mod code.
+     */
+    public static void unloadWorlds(Hashtable<Integer, long[]> worldTickTimes)
+    {
+        IntIterator queueIterator = unloadQueue.iterator();
+        while (queueIterator.hasNext())
+        {
+            int id = queueIterator.nextInt();
             Dimension dimension = dimensions.get(id);
             if (dimension.ticksWaited < ForgeModContainer.dimensionUnloadQueueDelay)
             {
@@ -428,8 +450,10 @@ public class DimensionManager
         dimensionMap.clear();
         if (compoundTag == null)
         {
-            for (Integer id : dimensions.keySet())
+            IntIterator iterator = dimensions.keySet().iterator();
+            while (iterator.hasNext())
             {
+                int id = iterator.nextInt();
                 if (id >= 0)
                 {
                     dimensionMap.set(id);

src/main/java/net/minecraftforge/server/command/CommandDimensions.java

@@ -0,0 +1,68 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2018.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.server.command;
+
+import it.unimi.dsi.fastutil.ints.IntSortedSet;
+import net.minecraft.command.CommandBase;
+import net.minecraft.command.CommandException;
+import net.minecraft.command.ICommandSender;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.text.TextComponentString;
+import net.minecraft.world.DimensionType;
+import net.minecraftforge.common.DimensionManager;
+
+import java.util.Map;
+
+public class CommandDimensions extends CommandBase
+{
+    @Override
+    public String getName()
+    {
+        return "dimensions";
+    }
+
+    @Override
+    public String getUsage(ICommandSender sender)
+    {
+        return "commands.forge.dimensions.usage";
+    }
+
+    @Override
+    public int getRequiredPermissionLevel()
+    {
+        return 0;
+    }
+
+    @Override
+    public boolean checkPermission(MinecraftServer server, ICommandSender sender)
+    {
+        return true;
+    }
+
+    @Override
+    public void execute(MinecraftServer server, ICommandSender sender, String[] args) throws CommandException
+    {
+        sender.sendMessage(TextComponentHelper.createComponentTranslation(sender, "commands.forge.dimensions.list"));
+        for (Map.Entry<DimensionType, IntSortedSet> entry : DimensionManager.getRegisteredDimensions().entrySet())
+        {
+            sender.sendMessage(new TextComponentString(entry.getKey().getName() + ": " + entry.getValue()));
+        }
+    }
+}

src/main/java/net/minecraftforge/server/command/ForgeCommand.java

@@ -33,6 +33,7 @@ public class ForgeCommand extends CommandTreeBase
         super.addSubcommand(new CommandGenerate());
         super.addSubcommand(new CommandEntity());
         super.addSubcommand(new CommandSetDimension());
+        super.addSubcommand(new CommandDimensions());
         super.addSubcommand(new CommandTreeHelp(this));
     }