Async path processor bugfixes

Fix villager AI (and other mobs)
Fix piston stacktrace & piston breaking pathfinding

README.md

@@ -11,30 +11,46 @@
 
 ## Features
 
-### Primary
-- **Xymb Linear Format**: Saves about 50% of disk space in OW/Nether and 95% in The End.
-- **Auto update**: Automatic upstream updates.
-
 ### Notable
-- **Entity throttling & removal**: Tweak entity tick frequency & max entity per region.
+- **Xymb Linear Format**: A Region file format that reduces disk space usage by about 50%.
+- **Async Pathfinding**: Petal async pathfinding fixed & reworked.
 - **Technical Minecraft**: Enable Vanilla exploits such as sand duping, RNG manipulation...
 
+### Other
+- **Small optimizations**: Increase server efficiency by disabling unnecessary features.
+- **Commands**: Restore few commands that were previously removed by Folia.
+
 ### Configuration
 
 ```yaml
 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
-gameplay:
-  server-mod-name: Kaiiju
-  shared-random-for-players: true
+  async-path-processing:
+    enable: false
+    max-threads: 0
+    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:
@@ -42,25 +58,22 @@ 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
-- **Static view distance**: Reduce RAM usage / Region size with a "static" view distance.
-- **Native world conversion**: Convert region file format at startup.
 - **Stash deduplication**: Make giant dupe stashes possible and lagless.
+- **Multithreaded Tracker**: Rework Petal multithreaded tracker.
+
+## Open to contributions
+- **Native world conversion**: Convert region file format at startup.
+- **Performance patch**: Any significative performance patch.
 
 ## Building
 

gradle.properties

@@ -2,7 +2,7 @@ group = dev.kaiijumc.kaiiju
 version = 1.20.1-R0.1-SNAPSHOT
 mcVersion = 1.20.1
 
-foliaRef = daacd4255022f3a1bf74dd3e84f751be838678ac
+foliaRef = b2d7bdb0bb5c841b4ccd096c0181664664ce97b1
 
 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 61c6bc2859235874aefac71e9e55162f0a89f29f..24bd63c596c9f61f1e89ec5b001b7cb7a29a09ff 100644
+index c4d28d887b4cc71dc713b1e3f46bc80f4484a95d..f50507ab85282d261985ce9b186581f5a7a50f79 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 61c6bc2859235874aefac71e9e55162f0a89f29f..24bd63c596c9f61f1e89ec5b001b7cb7
          // 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 4774d3f357d62b0818b4713f8085d05be09eaa5c..1bbd8b475cdc57fb15ca05ffe122220a5539da10 100644
+index 7099a44a2322ab390c21e74668c8657dcc9e5e87..475554797ffc279243ac0d88f1e619c3dd07bc4b 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 1bbd8b475cdc57fb15ca05ffe122220a5539da10..7f39e36037d55278d15399196459e51b885c5d1e 100644
+index 475554797ffc279243ac0d88f1e619c3dd07bc4b..475d0f3dd38e0407fa120d57e7d89216836538dd 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 7f39e36037d55278d15399196459e51b885c5d1e..66509fa23bfcde70abd3917eb774cf48d5d6da93 100644
+index 475d0f3dd38e0407fa120d57e7d89216836538dd..245c3e63588379f51780963ba91bc6bf0a3feda6 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..761019f86983daaea4fface519e052f8fb6de1cd 100644
+index 245c3e63588379f51780963ba91bc6bf0a3feda6..6efc8b37d4ee929522f5646c972565b99aa45de3 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..761019f86983daaea4fface519e052f8
 +                            // Kaiiju start
 +                            if (kaiijuConfig.enableEntityThrottling) {
 +                                dev.kaiijumc.kaiiju.KaiijuEntityThrottler.EntityThrottlerReturn throttle = regionizedWorldData.entityThrottler.tickLimiterShouldSkip(entity);
-+                                if (throttle.remove) entity.remove(Entity.RemovalReason.DISCARDED);
++                                if (throttle.remove && !entity.hasCustomName()) entity.remove(Entity.RemovalReason.DISCARDED);
 +                                if (throttle.skip) return;
 +                            }
 +                            // Kaiiju end

patches/server/0025-Vanilla-end-portal-teleportation.patch

@@ -5,12 +5,15 @@ Subject: [PATCH] Vanilla end portal teleportation
 
 
 diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
-index b971f35b69a930dddcf603207f524dc95e09f0fd..135573308662845ecc73fde1c620345e1f372538 100644
+index b971f35b69a930dddcf603207f524dc95e09f0fd..03895d35c02ff9422aaa0177eb0aa40e03fdc925 100644
 --- a/src/main/java/net/minecraft/world/entity/Entity.java
 +++ b/src/main/java/net/minecraft/world/entity/Entity.java
-@@ -4031,10 +4031,15 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
+@@ -4029,12 +4029,17 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
+                         targetPos, 16, // load 16 blocks to be safe from block physics
+                         ca.spottedleaf.concurrentutil.executor.standard.PrioritisedExecutor.Priority.HIGH,
                          (chunks) -> {
-                             ServerLevel.makeObsidianPlatform(destination, null, targetPos);
+-                            ServerLevel.makeObsidianPlatform(destination, null, targetPos);
++                            //ServerLevel.makeObsidianPlatform(destination, null, targetPos); // Kaiiju - Vanilla end teleportation - moved down
  
 +                            // Kaiiju start - Vanilla end teleportation
 +                            Vec3 finalPos;
@@ -25,3 +28,23 @@ index b971f35b69a930dddcf603207f524dc95e09f0fd..135573308662845ecc73fde1c620345e
                              );
                          }
                      );
+@@ -4221,6 +4226,10 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
+         if (!this.canPortalAsync(takePassengers)) {
+             return false;
+         }
++        // Kaiiju start - sync end platform spawning & entity teleportation
++        final java.util.function.Consumer<Entity> tpComplete = type == PortalType.END && destination.getTypeKey() == LevelStem.END ?
++              e -> ServerLevel.makeObsidianPlatform(destination, null, ServerLevel.END_SPAWN_POINT) : teleportComplete;
++        // Kaiiju end
+ 
+         Vec3 initialPosition = this.position();
+         ChunkPos initialPositionChunk = new ChunkPos(
+@@ -4279,7 +4288,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
+             // place
+             passengerTree.root.placeInAsync(
+                 originWorld, destination, Entity.TELEPORT_FLAG_LOAD_CHUNK | (takePassengers ? Entity.TELEPORT_FLAG_TELEPORT_PASSENGERS : 0L),
+-                passengerTree, teleportComplete
++                passengerTree, tpComplete // Kaiiju - vanilla end teleportation
+             );
+         });
+ 

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

@@ -0,0 +1,458 @@
+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..67f69540e6c217070f8d2af8908d4eb6f2b5c1c1 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);
+     }
+@@ -115,7 +138,10 @@ public class ChestBlockEntity extends RandomizableContainerBlockEntity implement
+     @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);
+         }
+@@ -187,7 +213,10 @@ 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