SakuraMC/patches/server/0048-Reduce-entity-tracker-player-updates.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <40902469+Samsuik@users.noreply.github.com>
Date: Thu, 30 Nov 2023 15:54:49 +0000
Subject: [PATCH] Reduce entity tracker player updates


diff --git a/src/main/java/net/minecraft/network/protocol/game/VecDeltaCodec.java b/src/main/java/net/minecraft/network/protocol/game/VecDeltaCodec.java
index 33d9131e9c75ef23cd637f5d6c39a2704a0c92a5..715994cbcb6c4dfa016eb9af49b40cde95ab16e7 100644
--- a/src/main/java/net/minecraft/network/protocol/game/VecDeltaCodec.java
+++ b/src/main/java/net/minecraft/network/protocol/game/VecDeltaCodec.java
@@ -47,4 +47,10 @@ public class VecDeltaCodec {
     public void setBase(Vec3 pos) {
         this.base = pos;
     }
+
+    // Sakura start
+    public Vec3 getBase() {
+        return base;
+    }
+    // Sakura end
 }
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index 24e0eaf25b2b366fd0e63a530c90f233c11d1bca..a09ac6167757b29ca2c6c78f1fd38039e8c19534 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -1159,6 +1159,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         try {
             for (TrackedEntity tracker : this.entityMap.values()) {
                 // update tracker entry
+                if (!tracker.shouldLookForPlayers()) continue; // Sakura - delay entities looking for nearby players
                 tracker.updatePlayers(tracker.entity.getPlayersInTrackRange());
             }
         } finally {
@@ -1333,6 +1334,14 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             this.lastSectionPos = SectionPos.of((EntityAccess) entity);
         }
 
+        // Sakura start - delay entities looking for nearby players
+        boolean shouldLookForPlayers() {
+            return entity instanceof net.minecraft.world.entity.player.Player // always update players
+                || entity.tickCount % serverEntity.updateInterval == 0
+                || serverEntity.travelledDistanceSquared() > range * range;
+        }
+        // Sakura end
+
         // Paper start - use distance map to optimise tracker
         com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> lastTrackerCandidates;
 
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index f7d8aaededd39ce52a9d0105f66fd759635b5288..be3eb957c8cf1bb5f5e2f448be73c0a14f245a4a 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -64,7 +64,7 @@ public class ServerEntity {
     private static final int FORCED_TELEPORT_PERIOD = 400;
     private final ServerLevel level;
     private final Entity entity;
-    private final int updateInterval;
+    final int updateInterval; // Sakura - private -> package
     private final boolean trackDelta;
     private final Consumer<Packet<?>> broadcast;
     private final VecDeltaCodec positionCodec = new VecDeltaCodec();
@@ -82,6 +82,12 @@ public class ServerEntity {
     // CraftBukkit start
     final Set<ServerPlayerConnection> trackedPlayers; // Paper - private -> package
 
+    // Sakura start
+    double travelledDistanceSquared() {
+        return entity.position().distanceToSqr(positionCodec.getBase());
+    }
+    // Sakura end
+
     public ServerEntity(ServerLevel worldserver, Entity entity, int i, boolean flag, Consumer<Packet<?>> consumer, Set<ServerPlayerConnection> trackedPlayers) {
         this.trackedPlayers = trackedPlayers;
         // CraftBukkit end