Avoid manipulating null paths

README.md

@@ -11,14 +11,13 @@
 
 ## Features
 
-### Notable
+### Primary
-- **Xymb Linear Format**: A Region file format that reduces disk space usage by about 50%.
+- **Xymb Linear Format**: Saves about 50% of disk space in OW/Nether and 95% in The End.
-- **Async Pathfinding**: Petal async pathfinding fixed & reworked.
+- **Auto update**: Automatic upstream updates.
-- **Technical Minecraft**: Enable Vanilla exploits such as sand duping, RNG manipulation...
 
-### Other
+### Notable
-- **Small optimizations**: Increase server efficiency by disabling unnecessary features.
+- **Entity throttling & removal**: Tweak entity tick frequency & max entity per region.
-- **Commands**: Restore few commands that were previously removed by Folia.
+- **Technical Minecraft**: Enable Vanilla exploits such as sand duping, RNG manipulation...
 
 ### Configuration
 
@@ -26,31 +25,16 @@
 network:
   send-null-entity-packets: true
   alternate-keepalive: false
-  kick-player-on-bad-packet: true
-gameplay:
-  server-mod-name: Kaiiju
-  shared-random-for-players: true
-region-format:
-  debug: false
 optimization:
   disable-vanish-api: false
   disable-player-stats: false
   disable-arm-swing-event: false
   disable-ensure-tick-thread-checks: false
-  async-path-processing:
+gameplay:
-    enable: false
+  server-mod-name: Kaiiju
-    max-threads: 0
+  shared-random-for-players: true
-    keepalive: 60
-    queue-capacity: 4096
 world-settings:
   default:
-    gameplay:
-      fix-void-trading: true
-      break-redstone-on-top-of-trap-doors-early: true
-      fix-tripwire-state-inconsistency: true
-      safe-teleportation: true
-      sand-duplication: false
-      teleport-async-on-high-velocity: false
     region-format:
       format: ANVIL
       linear:
@@ -58,22 +42,25 @@ world-settings:
         crash-on-broken-symlink: true
     optimization:
       shulker-box-drop-contents-when-destroyed: true
-      optimize-hoppers: true
-      tick-when-empty: true
       enable-entity-throttling: false
       disable-achievements: false
       disable-creatures-spawn-events: false
       disable-dolphin-swim-to-treasure: false
+    gameplay:
+      fix-void-trading: true
+      optimize-hoppers: true
+      tick-when-empty: true
+      break-redstone-on-top-of-trap-doors-early: true
+      fix-tripwire-state-inconsistency: true
+      safe-teleportation: true
+      sand-duplication: false
 ```
 Documentation: [Kaiiju Wiki](https://github.com/KaiijuMC/Kaiiju/wiki/Configuration)
 
 ### Roadmap
-- **Stash deduplication**: Make giant dupe stashes possible and lagless.
+- **Static view distance**: Reduce RAM usage / Region size with a "static" view distance.
-- **Multithreaded Tracker**: Rework Petal multithreaded tracker.
-
-## Open to contributions
 - **Native world conversion**: Convert region file format at startup.
-- **Performance patch**: Any significative performance patch.
+- **Stash deduplication**: Make giant dupe stashes possible and lagless.
 
 ## Building
 

gradle.properties

@@ -2,7 +2,7 @@ group = dev.kaiijumc.kaiiju
 version = 1.20.1-R0.1-SNAPSHOT
 mcVersion = 1.20.1
 
-foliaRef = b2d7bdb0bb5c841b4ccd096c0181664664ce97b1
+foliaRef = daacd4255022f3a1bf74dd3e84f751be838678ac
 
 org.gradle.caching=true
 org.gradle.parallel=true

patches/server/0012-Crash-on-broken-symlink.patch

@@ -42,7 +42,7 @@ index abf5e2a06af9853b58ac9107cd6e9787c4185c66..389c68c0becd2f69dc1004d0b383f1a8
          long expectedChunks = (long)regionFiles.length * (32L * 32L);
  
 diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
-index c4d28d887b4cc71dc713b1e3f46bc80f4484a95d..f50507ab85282d261985ce9b186581f5a7a50f79 100644
+index 61c6bc2859235874aefac71e9e55162f0a89f29f..24bd63c596c9f61f1e89ec5b001b7cb7a29a09ff 100644
 --- a/src/main/java/net/minecraft/server/level/ChunkMap.java
 +++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
 @@ -269,7 +269,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
@@ -64,7 +64,7 @@ index c4d28d887b4cc71dc713b1e3f46bc80f4484a95d..f50507ab85282d261985ce9b186581f5
          // Paper start
          this.dataRegionManager = new io.papermc.paper.chunk.SingleThreadChunkRegionManager(this.level, 2, (1.0 / 3.0), 1, 6, "Data", DataRegionData::new, DataRegionSectionData::new);
 diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
-index 7099a44a2322ab390c21e74668c8657dcc9e5e87..475554797ffc279243ac0d88f1e619c3dd07bc4b 100644
+index 4774d3f357d62b0818b4713f8085d05be09eaa5c..1bbd8b475cdc57fb15ca05ffe122220a5539da10 100644
 --- a/src/main/java/net/minecraft/server/level/ServerLevel.java
 +++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
 @@ -426,8 +426,8 @@ public class ServerLevel extends Level implements WorldGenLevel {

patches/server/0013-Toggle-void-trading.patch

@@ -22,7 +22,7 @@ index f3f824d0ab1a2a72825c40b67192386479a0b34c..95ed6cb7b94797187d1011cab344e187
      }
  }
 diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
-index 475554797ffc279243ac0d88f1e619c3dd07bc4b..475d0f3dd38e0407fa120d57e7d89216836538dd 100644
+index 1bbd8b475cdc57fb15ca05ffe122220a5539da10..7f39e36037d55278d15399196459e51b885c5d1e 100644
 --- a/src/main/java/net/minecraft/server/level/ServerLevel.java
 +++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
 @@ -2838,7 +2838,7 @@ public class ServerLevel extends Level implements WorldGenLevel {

patches/server/0015-Toggle-tick-level-when-empty.patch

@@ -22,7 +22,7 @@ index 6d7356cc07da58b1cef8d8963e790251d765de2c..601b9867d839f4928ba993ee8f00df9c
  
      public boolean fixVoidTrading = true;
 diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
-index 475d0f3dd38e0407fa120d57e7d89216836538dd..245c3e63588379f51780963ba91bc6bf0a3feda6 100644
+index 7f39e36037d55278d15399196459e51b885c5d1e..66509fa23bfcde70abd3917eb774cf48d5d6da93 100644
 --- a/src/main/java/net/minecraft/server/level/ServerLevel.java
 +++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
 @@ -798,7 +798,7 @@ public class ServerLevel extends Level implements WorldGenLevel {

patches/server/0022-Entity-ticking-throttling-removal-to-prevent-lag.patch

@@ -319,7 +319,7 @@ index 991e4c19763a34a6fead88363e007c2d11aad836..24a2d3f496727790f63cb66a2534d442
          dev.kaiijumc.kaiiju.KaiijuConfig.registerCommands();
          // Kaiiju end
 diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
-index 245c3e63588379f51780963ba91bc6bf0a3feda6..6efc8b37d4ee929522f5646c972565b99aa45de3 100644
+index 245c3e63588379f51780963ba91bc6bf0a3feda6..761019f86983daaea4fface519e052f8fb6de1cd 100644
 --- a/src/main/java/net/minecraft/server/level/ServerLevel.java
 +++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
 @@ -822,6 +822,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
@@ -337,7 +337,7 @@ index 245c3e63588379f51780963ba91bc6bf0a3feda6..6efc8b37d4ee929522f5646c972565b9
 +                            // Kaiiju start
 +                            if (kaiijuConfig.enableEntityThrottling) {
 +                                dev.kaiijumc.kaiiju.KaiijuEntityThrottler.EntityThrottlerReturn throttle = regionizedWorldData.entityThrottler.tickLimiterShouldSkip(entity);
-+                                if (throttle.remove && !entity.hasCustomName()) entity.remove(Entity.RemovalReason.DISCARDED);
++                                if (throttle.remove) entity.remove(Entity.RemovalReason.DISCARDED);
 +                                if (throttle.skip) return;
 +                            }
 +                            // Kaiiju end

patches/server/0044-Improve-container-checking-with-a-bitset.patch

@@ -1,457 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Paul Sauve <paul@technove.co>
-Date: Tue, 1 Aug 2023 03:38:09 +0200
-Subject: [PATCH] Improve container checking with a bitset
-
-
-diff --git a/src/main/java/dev/kaiijumc/kaiiju/structs/ItemListWithBitset.java b/src/main/java/dev/kaiijumc/kaiiju/structs/ItemListWithBitset.java
-new file mode 100644
-index 0000000000000000000000000000000000000000..ee32b7c4a1ae1e23149694ecba5ab7bd347d6ca6
---- /dev/null
-+++ b/src/main/java/dev/kaiijumc/kaiiju/structs/ItemListWithBitset.java
-@@ -0,0 +1,114 @@
-+package dev.kaiijumc.kaiiju.structs;
-+
-+
-+import net.minecraft.core.NonNullList;
-+import net.minecraft.world.item.ItemStack;
-+import org.apache.commons.lang.Validate;
-+import org.jetbrains.annotations.NotNull;
-+
-+import java.util.AbstractList;
-+import java.util.Arrays;
-+import java.util.List;
-+
-+public class ItemListWithBitset extends AbstractList<ItemStack> {
-+    public static ItemListWithBitset fromList(List<ItemStack> list) {
-+        if (list instanceof ItemListWithBitset ours) {
-+            return ours;
-+        }
-+        return new ItemListWithBitset(list);
-+    }
-+
-+    private static ItemStack[] createArray(int size) {
-+        ItemStack[] array = new ItemStack[size];
-+        Arrays.fill(array, ItemStack.EMPTY);
-+        return array;
-+    }
-+
-+    private final ItemStack[] items;
-+
-+    private long bitSet = 0;
-+    private final long allBits;
-+
-+    private static class OurNonNullList extends NonNullList<ItemStack> {
-+        protected OurNonNullList(List<ItemStack> delegate) {
-+            super(delegate, ItemStack.EMPTY);
-+        }
-+    }
-+
-+    public final NonNullList<ItemStack> nonNullList = new OurNonNullList(this);
-+
-+    private ItemListWithBitset(List<ItemStack> list) {
-+        this(list.size());
-+
-+        for (int i = 0; i < list.size(); i++) {
-+            this.set(i, list.get(i));
-+        }
-+    }
-+
-+    public ItemListWithBitset(int size) {
-+        Validate.isTrue(size < Long.BYTES * 8, "size is too large");
-+
-+        this.items = createArray(size);
-+        this.allBits = ((1L << size) - 1);
-+    }
-+
-+    public boolean isCompletelyEmpty() {
-+        return this.bitSet == 0;
-+    }
-+
-+    public boolean hasFullStacks() {
-+        return (this.bitSet & this.allBits) == allBits;
-+    }
-+
-+    @Override
-+    public ItemStack set(int index, @NotNull ItemStack itemStack) {
-+        ItemStack existing = this.items[index];
-+
-+        this.items[index] = itemStack;
-+
-+        if (itemStack == ItemStack.EMPTY) {
-+            this.bitSet &= ~(1L << index);
-+        } else {
-+            this.bitSet |= 1L << index;
-+        }
-+
-+        return existing;
-+    }
-+
-+    @NotNull
-+    @Override
-+    public ItemStack get(int var0) {
-+        return this.items[var0];
-+    }
-+
-+    @Override
-+    public int size() {
-+        return this.items.length;
-+    }
-+
-+    @Override
-+    public void clear() {
-+        Arrays.fill(this.items, ItemStack.EMPTY);
-+    }
-+
-+    // these are unsupported for block inventories which have a static size
-+    @Override
-+    public void add(int var0, ItemStack var1) {
-+        throw new UnsupportedOperationException();
-+    }
-+
-+    @Override
-+    public ItemStack remove(int var0) {
-+        throw new UnsupportedOperationException();
-+    }
-+
-+    @Override
-+    public String toString() {
-+        return "ItemListWithBitset{" +
-+          "items=" + Arrays.toString(items) +
-+          ", bitSet=" + Long.toString(bitSet, 2) +
-+          ", allBits=" + Long.toString(allBits, 2) +
-+          ", size=" + this.items.length +
-+          '}';
-+    }
-+}
-diff --git a/src/main/java/net/minecraft/world/CompoundContainer.java b/src/main/java/net/minecraft/world/CompoundContainer.java
-index 241fec02e6869c638d3a160819b32173a081467b..62848ca68f532fa14241320df76d180c13072c34 100644
---- a/src/main/java/net/minecraft/world/CompoundContainer.java
-+++ b/src/main/java/net/minecraft/world/CompoundContainer.java
-@@ -64,6 +64,23 @@ public class CompoundContainer implements Container {
-         this.container2 = second;
-     }
- 
-+    // Kaiiju start - airplane - improve container checking with a bitset
-+    @Override
-+   public boolean hasEmptySlot(net.minecraft.core.Direction enumdirection) {
-+        return this.container1.hasEmptySlot(null) || this.container2.hasEmptySlot(null);
-+    }
-+
-+    @Override
-+   public boolean isCompletelyFull(net.minecraft.core.Direction enumdirection) {
-+        return this.container1.isCompletelyFull(null) && this.container2.isCompletelyFull(null);
-+    }
-+
-+    @Override
-+    public boolean isCompletelyEmpty(net.minecraft.core.Direction enumdirection) {
-+        return this.container1.isCompletelyEmpty(null) && this.container2.isCompletelyEmpty(null);
-+    }
-+    // Kaiiju end
-+
-     @Override
-     public int getContainerSize() {
-         return this.container1.getContainerSize() + this.container2.getContainerSize();
-diff --git a/src/main/java/net/minecraft/world/Container.java b/src/main/java/net/minecraft/world/Container.java
-index 04b1531572e8fff1e46fe1c94e7fc863841e0f66..ac1e21a4fc210424ea57c247d03914c54129de9c 100644
---- a/src/main/java/net/minecraft/world/Container.java
-+++ b/src/main/java/net/minecraft/world/Container.java
-@@ -13,6 +13,63 @@ import org.bukkit.craftbukkit.entity.CraftHumanEntity;
- // CraftBukkit end
- 
- public interface Container extends Clearable {
-+    // Kaiiju start - airplane - allow the inventory to override and optimize these frequent calls
-+    default boolean hasEmptySlot(@org.jetbrains.annotations.Nullable net.minecraft.core.Direction enumdirection) { // there is a slot with 0 items in it
-+        if (this instanceof WorldlyContainer worldlyContainer) {
-+            for (int i : worldlyContainer.getSlotsForFace(enumdirection)) {
-+                if (this.getItem(i).isEmpty()) {
-+                    return true;
-+                }
-+            }
-+        } else {
-+            int size = this.getContainerSize();
-+            for (int i = 0; i < size; i++) {
-+                if (this.getItem(i).isEmpty()) {
-+                    return true;
-+                }
-+            }
-+        }
-+        return false;
-+    }
-+
-+    default boolean isCompletelyFull(@org.jetbrains.annotations.Nullable net.minecraft.core.Direction enumdirection) { // every stack is maxed
-+        if (this instanceof WorldlyContainer worldlyContainer) {
-+            for (int i : worldlyContainer.getSlotsForFace(enumdirection)) {
-+                ItemStack itemStack = this.getItem(i);
-+                if (itemStack.getCount() < itemStack.getMaxStackSize()) {
-+                    return false;
-+                }
-+            }
-+        } else {
-+            int size = this.getContainerSize();
-+            for (int i = 0; i < size; i++) {
-+                ItemStack itemStack = this.getItem(i);
-+                if (itemStack.getCount() < itemStack.getMaxStackSize()) {
-+                    return false;
-+                }
-+            }
-+        }
-+        return true;
-+    }
-+
-+    default boolean isCompletelyEmpty(@org.jetbrains.annotations.Nullable net.minecraft.core.Direction enumdirection) {
-+        if (this instanceof WorldlyContainer worldlyContainer) {
-+            for (int i : worldlyContainer.getSlotsForFace(enumdirection)) {
-+                if (!this.getItem(i).isEmpty()) {
-+                    return false;
-+                }
-+            }
-+        } else {
-+            int size = this.getContainerSize();
-+            for (int i = 0; i < size; i++) {
-+                if (!this.getItem(i).isEmpty()) {
-+                    return false;
-+                }
-+            }
-+        }
-+        return true;
-+    }
-+    // Kaiiju end
- 
-     int LARGE_MAX_STACK_SIZE = 64;
-     int DEFAULT_DISTANCE_LIMIT = 8;
-diff --git a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java
-index 272095d7a09ab41227d741172735f66fd2798ce1..1f2e2d7726abd63bb46697697c91696387c819a2 100644
---- a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java
-+++ b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java
-@@ -28,6 +28,7 @@ import org.bukkit.inventory.InventoryHolder;
- public abstract class AbstractMinecartContainer extends AbstractMinecart implements ContainerEntity {
- 
-     private NonNullList<ItemStack> itemStacks;
-+    private dev.kaiijumc.kaiiju.structs.ItemListWithBitset itemStacksOptimized; // Kaiiju - airplane - implement ItemListWithBitset
-     @Nullable
-     public ResourceLocation lootTable;
-     public long lootTableSeed;
-@@ -89,12 +90,18 @@ public abstract class AbstractMinecartContainer extends AbstractMinecart impleme
- 
-     protected AbstractMinecartContainer(EntityType<?> type, Level world) {
-         super(type, world);
--        this.itemStacks = NonNullList.withSize(this.getContainerSize(), ItemStack.EMPTY); // CraftBukkit - SPIGOT-3513
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.itemStacksOptimized = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(this.getContainerSize()); // CraftBukkit - SPIGOT-3513
-+        this.itemStacks = this.itemStacksOptimized.nonNullList;
-+        // Kaiiju end
-     }
- 
-     protected AbstractMinecartContainer(EntityType<?> type, double x, double y, double z, Level world) {
-         super(type, world, x, y, z);
--        this.itemStacks = NonNullList.withSize(this.getContainerSize(), ItemStack.EMPTY); // CraftBukkit - SPIGOT-3513
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.itemStacksOptimized = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(this.getContainerSize()); // CraftBukkit - SPIGOT-3513
-+        this.itemStacks = this.itemStacksOptimized.nonNullList;
-+        // Kaiiju end
-     }
- 
-     @Override
-@@ -156,6 +163,10 @@ public abstract class AbstractMinecartContainer extends AbstractMinecart impleme
-     protected void readAdditionalSaveData(CompoundTag nbt) {
-         super.readAdditionalSaveData(nbt);
-         this.lootableData.loadNbt(nbt); // Paper
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.itemStacksOptimized = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(this.getContainerSize()); // CraftBukkit - SPIGOT-3513
-+        this.itemStacks = this.itemStacksOptimized.nonNullList;
-+        // Kaiiju end
-         this.readChestVehicleSaveData(nbt);
-     }
- 
-diff --git a/src/main/java/net/minecraft/world/level/block/entity/ChestBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/ChestBlockEntity.java
-index a71414397bd45ee7bcacfeef0041d80dfa25f114..93db8c056f1ec0f998b480cfdea3666cbc54603c 100644
---- a/src/main/java/net/minecraft/world/level/block/entity/ChestBlockEntity.java
-+++ b/src/main/java/net/minecraft/world/level/block/entity/ChestBlockEntity.java
-@@ -31,6 +31,7 @@ import org.bukkit.entity.HumanEntity;
- public class ChestBlockEntity extends RandomizableContainerBlockEntity implements LidBlockEntity {
- 
-     private static final int EVENT_SET_OPEN_COUNT = 1;
-+    private dev.kaiijumc.kaiiju.structs.ItemListWithBitset optimizedItems; // Kaiiju - airplane - implement ItemListWithBitset
-     private NonNullList<ItemStack> items;
-     public final ContainerOpenersCounter openersCounter;
-     private final ChestLidController chestLidController;
-@@ -65,9 +66,14 @@ public class ChestBlockEntity extends RandomizableContainerBlockEntity implement
-     }
-     // CraftBukkit end
- 
-+    private final boolean isNative = getClass().equals(ChestBlockEntity.class); // Kaiiju - airplane
-+
-     protected ChestBlockEntity(BlockEntityType<?> type, BlockPos pos, BlockState state) {
-         super(type, pos, state);
--        this.items = NonNullList.withSize(27, ItemStack.EMPTY);
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.optimizedItems = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(27);
-+        this.items = this.optimizedItems.nonNullList;
-+        // Kaiiju end
-         this.openersCounter = new ContainerOpenersCounter() {
-             @Override
-             protected void onOpen(Level world, BlockPos pos, BlockState state) {
-@@ -98,6 +104,23 @@ public class ChestBlockEntity extends RandomizableContainerBlockEntity implement
-         this.chestLidController = new ChestLidController();
-     }
- 
-+    // Kaiiju start - airplane - improve container checking with a bitset
-+    @Override
-+    public boolean hasEmptySlot(Direction enumdirection) {
-+        return isNative ? !this.optimizedItems.hasFullStacks() : super.hasEmptySlot(enumdirection);
-+    }
-+
-+    @Override
-+    public boolean isCompletelyFull(Direction enumdirection) {
-+        return isNative ? this.optimizedItems.hasFullStacks() && super.isCompletelyFull(enumdirection) : super.isCompletelyFull(enumdirection);
-+    }
-+
-+    @Override
-+    public boolean isCompletelyEmpty(Direction enumdirection) {
-+        return isNative && this.optimizedItems.isCompletelyEmpty() || super.isCompletelyEmpty(enumdirection);
-+    }
-+    // Kaiiju end
-+
-     public ChestBlockEntity(BlockPos pos, BlockState state) {
-         this(BlockEntityType.CHEST, pos, state);
-     }
-@@ -115,6 +138,10 @@ public class ChestBlockEntity extends RandomizableContainerBlockEntity implement
-     @Override
-     public void load(CompoundTag nbt) {
-         super.load(nbt);
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.optimizedItems = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(this.getContainerSize());
-+        this.items = this.optimizedItems.nonNullList;
-+        // Kaiiju end
-         this.items = NonNullList.withSize(this.getContainerSize(), ItemStack.EMPTY);
-         if (!this.tryLoadLootTable(nbt)) {
-             ContainerHelper.loadAllItems(nbt, this.items);
-@@ -187,7 +214,10 @@ public class ChestBlockEntity extends RandomizableContainerBlockEntity implement
- 
-     @Override
-     protected void setItems(NonNullList<ItemStack> list) {
--        this.items = list;
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.optimizedItems = dev.kaiijumc.kaiiju.structs.ItemListWithBitset.fromList(list);
-+        this.items = this.optimizedItems.nonNullList;
-+        // Kaiiju end
-     }
- 
-     @Override
-diff --git a/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java
-index 762b763f271c3208b4f8a7e346897207ec5beb6c..a212a62bc2b43b55e9040e2de8360d6e55a7dd86 100644
---- a/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java
-+++ b/src/main/java/net/minecraft/world/level/block/entity/HopperBlockEntity.java
-@@ -48,6 +48,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
-     public static final int MOVE_ITEM_SPEED = 8;
-     public static final int HOPPER_CONTAINER_SIZE = 5;
-     private NonNullList<ItemStack> items;
-+    private dev.kaiijumc.kaiiju.structs.ItemListWithBitset optimizedItems; // Kaiiju - airplane - implement ItemListWithBitset
-     private int cooldownTime;
-     private long tickedGameTime;
- 
-@@ -83,14 +84,37 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
- 
-     public HopperBlockEntity(BlockPos pos, BlockState state) {
-         super(BlockEntityType.HOPPER, pos, state);
--        this.items = NonNullList.withSize(5, ItemStack.EMPTY);
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.optimizedItems = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(5);
-+        this.items = this.optimizedItems.nonNullList;
-+        // Kaiiju end
-         this.cooldownTime = -1;
-     }
- 
-+    // Kaiiju start - airplane - improve container checking with a bitset
-+    @Override
-+    public boolean hasEmptySlot(Direction enumdirection) {
-+        return !this.optimizedItems.hasFullStacks();
-+    }
-+
-+    @Override
-+    public boolean isCompletelyFull(Direction enumdirection) {
-+        return this.optimizedItems.hasFullStacks() && super.isCompletelyFull(enumdirection);
-+    }
-+
-+    @Override
-+    public boolean isCompletelyEmpty(Direction enumdirection) {
-+        return this.optimizedItems.isCompletelyEmpty() || super.isCompletelyEmpty(enumdirection);
-+    }
-+    // Kaiiju end
-+
-     @Override
-     public void load(CompoundTag nbt) {
-         super.load(nbt);
--        this.items = NonNullList.withSize(this.getContainerSize(), ItemStack.EMPTY);
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.optimizedItems = new dev.kaiijumc.kaiiju.structs.ItemListWithBitset(this.getContainerSize());
-+        this.items = this.optimizedItems.nonNullList;
-+        // Kaiiju end
-         if (!this.tryLoadLootTable(nbt)) {
-             ContainerHelper.loadAllItems(nbt, this.items);
-         }
-@@ -162,7 +186,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
-                     flag = HopperBlockEntity.ejectItems(world, pos, state, (Container) blockEntity, blockEntity); // CraftBukkit
-                 }
- 
--                if (!blockEntity.inventoryFull()) {
-+                if (!blockEntity.optimizedItems.hasFullStacks() || !blockEntity.inventoryFull()) { // Kaiiju - airplane
-                     flag |= booleansupplier.getAsBoolean();
-                 }
- 
-@@ -455,11 +479,11 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
-     }
- 
-     private static boolean isFullContainer(Container inventory, Direction direction) {
--        return allMatch(inventory, direction, STACK_SIZE_TEST); // Paper - no streams
-+        return inventory.isCompletelyFull(direction); // Kaiiju - airplane - use bitsets
-     }
- 
-     private static boolean isEmptyContainer(Container inv, Direction facing) {
--        return allMatch(inv, facing, IS_EMPTY_TEST);
-+        return inv.isCompletelyEmpty(facing); // Kaiiju - airplane - use bitsets
-     }
- 
-     public static boolean suckInItems(Level world, Hopper hopper) {
-@@ -649,7 +673,7 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
- 
-         if (HopperBlockEntity.canPlaceItemInContainer(to, stack, slot, side)) {
-             boolean flag = false;
--            boolean flag1 = to.isEmpty();
-+            boolean flag1 = to.isCompletelyEmpty(side); // Kaiiju - airplane - use bitsets
- 
-             if (itemstack1.isEmpty()) {
-                 // Spigot start - SPIGOT-6693, InventorySubcontainer#setItem
-@@ -844,7 +868,10 @@ public class HopperBlockEntity extends RandomizableContainerBlockEntity implemen
- 
-     @Override
-     protected void setItems(NonNullList<ItemStack> list) {
--        this.items = list;
-+        // Kaiiju start - airplane - use ItemListWithBitset
-+        this.optimizedItems = dev.kaiijumc.kaiiju.structs.ItemListWithBitset.fromList(list);
-+        this.items = this.optimizedItems.nonNullList;
-+        // Kaiiju end
-     }
- 
-     public static void entityInside(Level world, BlockPos pos, BlockState state, Entity entity, HopperBlockEntity blockEntity) {
-diff --git a/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java
-index 081691f9710ff1115e4308f79ed49fbc38941193..648e28c5fba5c62e65f83fbb5ebc8836ffb166a9 100644
---- a/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java
-+++ b/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java
-@@ -95,14 +95,7 @@ public abstract class RandomizableContainerBlockEntity extends BaseContainerBloc
-     @Override
-     public boolean isEmpty() {
-         this.unpackLootTable((Player)null);
--        // Paper start
--        for (final ItemStack itemStack : this.getItems()) {
--            if (!itemStack.isEmpty()) {
--                return false;
--            }
--        }
--        return true;
--        // Paper end
-+        return this.isCompletelyEmpty(null); // Kaiiju - airplane - use super
-     }
- 
-     @Override