Use FastUtil over Trove for maps/collections to reduce memory usage

This should significantly decrease the amount of RAM being used by Geyser. Previously it was using 300mb - 400mb on average. This has dropped it down to 80mb - 120mb. Ideally I'd like to decrease this value further, but that will require some more work.

connector/src/main/java/org/geysermc/connector/entity/Entity.java

@@ -34,6 +34,8 @@ import com.nukkitx.protocol.bedrock.data.EntityDataDictionary;
 import com.nukkitx.protocol.bedrock.data.EntityFlag;
 import com.nukkitx.protocol.bedrock.data.EntityFlags;
 import com.nukkitx.protocol.bedrock.packet.*;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import it.unimi.dsi.fastutil.longs.LongSet;
 import lombok.Getter;
 import lombok.Setter;
 import org.geysermc.connector.console.GeyserLogger;
@@ -69,7 +71,7 @@ public class Entity {
 
     protected boolean valid;
 
-    protected Set<Long> passengers = new HashSet<>();
+    protected LongSet passengers = new LongOpenHashSet();
     protected Map<AttributeType, Attribute> attributes = new HashMap<>();
     protected EntityDataDictionary metadata = new EntityDataDictionary();
 

connector/src/main/java/org/geysermc/connector/network/session/cache/EntityCache.java

@@ -25,6 +25,10 @@
 
 package org.geysermc.connector.network.session.cache;
 
+import it.unimi.dsi.fastutil.longs.Long2LongMap;
+import it.unimi.dsi.fastutil.longs.Long2LongOpenHashMap;
+import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
 import lombok.Getter;
 import org.geysermc.connector.entity.Entity;
 import org.geysermc.connector.entity.PlayerEntity;
@@ -41,8 +45,8 @@ public class EntityCache {
     private GeyserSession session;
 
     @Getter
-    private Map<Long, Entity> entities = new HashMap<>();
+    private Long2ObjectMap<Entity> entities = new Long2ObjectOpenHashMap<>();
-    private Map<Long, Long> entityIdTranslations = new HashMap<>();
+    private Long2LongMap entityIdTranslations = new Long2LongOpenHashMap();
     private Map<UUID, PlayerEntity> playerEntities = new HashMap<>();
     private Map<UUID, Long> bossbars = new HashMap<>();
 
@@ -62,13 +66,11 @@ public class EntityCache {
 
     public boolean removeEntity(Entity entity, boolean force) {
         if (entity != null && entity.isValid() && (force || entity.despawnEntity(session))) {
-            Long geyserId = entityIdTranslations.remove(entity.getEntityId());
+            long geyserId = entityIdTranslations.remove(entity.getEntityId());
-            if (geyserId != null) {
             entities.remove(geyserId);
             if (entity.is(PlayerEntity.class)) {
                 playerEntities.remove(entity.as(PlayerEntity.class).getUuid());
             }
-            }
             return true;
         }
         return false;

connector/src/main/java/org/geysermc/connector/network/session/cache/WindowCache.java

@@ -26,6 +26,8 @@
 package org.geysermc.connector.network.session.cache;
 
 import com.nukkitx.protocol.bedrock.packet.ModalFormRequestPacket;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import lombok.Getter;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.api.window.FormWindow;
@@ -38,7 +40,7 @@ public class WindowCache {
     private GeyserSession session;
 
     @Getter
-    private Map<Integer, FormWindow> windows = new HashMap<Integer, FormWindow>();
+    private Int2ObjectMap<FormWindow> windows = new Int2ObjectOpenHashMap<>();
 
     public WindowCache(GeyserSession session) {
         this.session = session;

connector/src/main/java/org/geysermc/connector/network/translators/item/ItemTranslator.java

@@ -79,7 +79,7 @@ public class ItemTranslator {
     }
 
     public ItemEntry getItem(ItemData data) {
-        for (ItemEntry itemEntry : Toolbox.ITEM_ENTRIES.valueCollection()) {
+        for (ItemEntry itemEntry : Toolbox.ITEM_ENTRIES.values()) {
             if (itemEntry.getBedrockId() == data.getId() && itemEntry.getBedrockData() == data.getDamage()) {
                 return itemEntry;
             }

connector/src/main/java/org/geysermc/connector/utils/Toolbox.java

@@ -7,8 +7,8 @@ import com.nukkitx.nbt.tag.CompoundTag;
 import com.nukkitx.nbt.tag.ListTag;
 import com.nukkitx.protocol.bedrock.packet.StartGamePacket;
 
-import gnu.trove.map.TIntObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
-import gnu.trove.map.hash.TIntObjectHashMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import org.geysermc.connector.GeyserConnector;
 import org.geysermc.connector.console.GeyserLogger;
 import org.geysermc.connector.network.translators.block.BlockEntry;
@@ -23,8 +23,8 @@ public class Toolbox {
     public static final Collection<StartGamePacket.ItemEntry> ITEMS = new ArrayList<>();
     public static ListTag<CompoundTag> BLOCKS;
 
-    public static final TIntObjectMap<ItemEntry> ITEM_ENTRIES = new TIntObjectHashMap<>();
+    public static final Int2ObjectMap<ItemEntry> ITEM_ENTRIES = new Int2ObjectOpenHashMap<>();
-    public static final TIntObjectMap<BlockEntry> BLOCK_ENTRIES = new TIntObjectHashMap<>();
+    public static final Int2ObjectMap<BlockEntry> BLOCK_ENTRIES = new Int2ObjectOpenHashMap<>();
 
     public static void init() {
         InputStream stream = GeyserConnector.class.getClassLoader().getResourceAsStream("bedrock/runtime_block_states.dat");

connector/src/main/java/org/geysermc/connector/world/chunk/BlockStorage.java

@@ -1,12 +1,15 @@
 package org.geysermc.connector.world.chunk;
 
 import com.nukkitx.network.VarInts;
-import gnu.trove.list.array.TIntArrayList;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.IntArrayList;
+import it.unimi.dsi.fastutil.ints.IntList;
 import org.geysermc.connector.world.GlobalBlockPalette;
 import org.geysermc.connector.world.chunk.bitarray.BitArray;
 import org.geysermc.connector.world.chunk.bitarray.BitArrayVersion;
 
+import java.util.function.IntConsumer;
+
 /**
  * Adapted from NukkitX: https://github.com/NukkitX/Nukkit
  */
@@ -14,7 +17,7 @@ public class BlockStorage {
 
     private static final int SIZE = 4096;
 
-    private final TIntArrayList palette;
+    private final IntList palette;
     private BitArray bitArray;
 
     public BlockStorage() {
@@ -23,11 +26,11 @@ public class BlockStorage {
 
     public BlockStorage(BitArrayVersion version) {
         this.bitArray = version.createPalette(SIZE);
-        this.palette = new TIntArrayList(16, -1);
+        this.palette = new IntArrayList(16);
         this.palette.add(0); // Air is at the start of every palette.
     }
 
-    private BlockStorage(BitArray bitArray, TIntArrayList palette) {
+    private BlockStorage(BitArray bitArray, IntArrayList palette) {
         this.palette = palette;
         this.bitArray = bitArray;
     }
@@ -57,10 +60,7 @@ public class BlockStorage {
         }
 
         VarInts.writeInt(buffer, palette.size());
-        palette.forEach(id -> {
+        palette.forEach((IntConsumer) id -> VarInts.writeInt(buffer, id));
-            VarInts.writeInt(buffer, id);
-            return true;
-        });
     }
 
     private void onResize(BitArrayVersion version) {
@@ -109,6 +109,6 @@ public class BlockStorage {
     }
 
     public BlockStorage copy() {
-        return new BlockStorage(this.bitArray.copy(), new TIntArrayList(this.palette));
+        return new BlockStorage(this.bitArray.copy(), new IntArrayList(this.palette));
     }
 }