From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Bacteriawa <A3167717663@hotmail.com>
Date: Tue, 21 Apr 2026 01:41:14 +0800
Subject: [PATCH] Kaiiju: Entity tick and removal limiter

Co-authored by: Xymb <xymb@endcrystal.me>
As part of: Kaiiju (https://github.com/KaiijuMC/Kaiiju/blob/c2b7aec8f7b418a39a2ec408e6411e6f752379da/patches/server/0021-Entity-ticking-throttling-removal-to-prevent-lag.patch)
Licensed under: GPL-3.0 (https://github.com/KaiijuMC/Kaiiju/blob/c2b7aec8f7b418a39a2ec408e6411e6f752379da/LICENSE)

diff --git a/io/papermc/paper/threadedregions/RegionizedWorldData.java b/io/papermc/paper/threadedregions/RegionizedWorldData.java
index 3333fc2a564531ece613ed2ac77db99c59ec7390..df9a8fba86b61d2d2f82e40e0f317cab84faa2ff 100644
--- a/io/papermc/paper/threadedregions/RegionizedWorldData.java
+++ b/io/papermc/paper/threadedregions/RegionizedWorldData.java
@@ -354,6 +354,7 @@ public final class RegionizedWorldData {
     private final IteratorSafeOrderedReferenceSet<Mob> navigatingMobs = new IteratorSafeOrderedReferenceSet<>();
     public final ReferenceList<Entity> trackerEntities = new ReferenceList<>(EMPTY_ENTITY_ARRAY); // Moonrise - entity tracker
     public final ReferenceList<Entity> trackerUnloadedEntities = new ReferenceList<>(EMPTY_ENTITY_ARRAY); // Moonrise - entity tracker
+    public final dev.kaiijumc.kaiiju.KaiijuEntityThrottler entityThrottler = new dev.kaiijumc.kaiiju.KaiijuEntityThrottler(); // Kaiiju
 
     // block ticking
     private final ObjectLinkedOpenHashSet<BlockEventData> blockEvents = new ObjectLinkedOpenHashSet<>();
diff --git a/net/minecraft/server/level/ServerLevel.java b/net/minecraft/server/level/ServerLevel.java
index 878a00bb28223b2719b4ce7c5d715e0346364770..e89d2af26ffe83e71cfb733cfdbec542f845f4e5 100644
--- a/net/minecraft/server/level/ServerLevel.java
+++ b/net/minecraft/server/level/ServerLevel.java
@@ -912,6 +912,7 @@ public class ServerLevel extends Level implements WorldGenLevel, ServerEntityGet
             }
 
             foliaProfiler.startTimer(ca.spottedleaf.leafprofiler.LProfilerRegistry.ACTIVATE_ENTITIES); try { // Folia - profiler
+                if (dev.kaiijumc.kaiiju.KaiijuEntityLimits.enabled) regionizedWorldData.entityThrottler.tickLimiterStart(); // Kaiiju
             io.papermc.paper.entity.activation.ActivationRange.activateEntities(this); // Paper - EAR
             } finally { foliaProfiler.stopTimer(ca.spottedleaf.leafprofiler.LProfilerRegistry.ACTIVATE_ENTITIES); } // Folia - profiler
             foliaProfiler.startTimer(ca.spottedleaf.leafprofiler.LProfilerRegistry.ENTITY_TICK); try { // Folia - profiler
@@ -933,6 +934,13 @@ public class ServerLevel extends Level implements WorldGenLevel, ServerEntityGet
 
                                         entity.stopRiding();
                                     }
+                                    // Kaiiju start
+                                    if (dev.kaiijumc.kaiiju.KaiijuEntityLimits.enabled) {
+                                        dev.kaiijumc.kaiiju.KaiijuEntityThrottler.EntityThrottlerReturn throttle = regionizedWorldData.entityThrottler.tickLimiterShouldSkip(entity);
+                                        if (throttle.remove && !entity.hasCustomName()) entity.remove(Entity.RemovalReason.DISCARDED);
+                                        if (throttle.skip) return;
+                                    }
+                                    // Kaiiju end
 
                                     profiler.push("tick");
                                     this.guardEntityTick(this::tickNonPassenger, entity);
@@ -942,6 +950,7 @@ public class ServerLevel extends Level implements WorldGenLevel, ServerEntityGet
                         }
                     }
                 );
+                if (dev.kaiijumc.kaiiju.KaiijuEntityLimits.enabled) regionizedWorldData.entityThrottler.tickLimiterFinish(regionizedWorldData); // Kaiiju
             } finally { foliaProfiler.stopTimer(ca.spottedleaf.leafprofiler.LProfilerRegistry.ENTITY_TICK); } // Folia - profiler
             if (this.paperConfig().unsupportedSettings.ticking.blockEntities) { // Paper - option to disable ticking
             profiler.popPush("blockEntities");
diff --git a/net/minecraft/world/entity/EntityType.java b/net/minecraft/world/entity/EntityType.java
index 6efaa78faca15c7a48bdffb24480d1bac29f3ba8..31619890f1bd4f458b6f9a31fac8cefaafe09e8e 100644
--- a/net/minecraft/world/entity/EntityType.java
+++ b/net/minecraft/world/entity/EntityType.java
@@ -73,6 +73,7 @@ public class EntityType<T extends Entity> implements EntityTypeTest<Entity, T>,
     private final float spawnDimensionsScale;
     private final FeatureFlagSet requiredFeatures;
     private final boolean allowedInPeaceful;
+    public volatile dev.kaiijumc.kaiiju.KaiijuEntityLimits.EntityLimit entityLimit;
 
     public static Identifier getKey(final EntityType<?> type) {
         return BuiltInRegistries.ENTITY_TYPE.getKey(type);