Leaf/patches/server/0043-Optimize-Minecart-collisions.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Dreeam <61569423+Dreeam-qwq@users.noreply.github.com>
Date: Sat, 6 Apr 2024 22:57:41 -0400
Subject: [PATCH] Optimize Minecart collisions

Skip tick collisions to to prevent lag causing by massive stacked Minecart
Useful for anarchy server.

diff --git a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java
index eb5bd5cfd131042e366872bf599a315d83dc732b..9bf74e76a2b2fef92bef37fbaee2171b7f7a357d 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecart.java
@@ -5,7 +5,8 @@ import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 import com.google.common.collect.UnmodifiableIterator;
 import com.mojang.datafixers.util.Pair;
-import java.util.Iterator;
+
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import javax.annotation.Nullable;
@@ -389,15 +390,15 @@ public abstract class AbstractMinecart extends VehicleEntity {
                 this.level().getCraftServer().getPluginManager().callEvent(new org.bukkit.event.vehicle.VehicleMoveEvent(vehicle, from, to));
             }
             // CraftBukkit end
-            if (this.getMinecartType() == AbstractMinecart.Type.RIDEABLE && this.getDeltaMovement().horizontalDistanceSqr() > 0.01D) {
+            // Leaf start - Optimize Minecart collision handling
+            // The logic below is used to get list of entities around Minecart
+            // and handle behaviors for their collisions with each other
+            if (!org.dreeam.leaf.config.modules.opt.OptimizeMinecart.enabled || this.tickCount % org.dreeam.leaf.config.modules.opt.OptimizeMinecart.skipTickCount == 0) {
+            if (this.getMinecartType() == AbstractMinecart.Type.RIDEABLE && (org.dreeam.leaf.config.modules.opt.OptimizeMinecart.enabled || this.getDeltaMovement().horizontalDistanceSqr() > 0.01D)) {
                 List<Entity> list = this.level().getEntities((Entity) this, this.getBoundingBox().inflate(0.20000000298023224D, 0.0D, 0.20000000298023224D), EntitySelector.pushableBy(this));
 
                 if (!list.isEmpty()) {
-                    Iterator iterator = list.iterator();
-
-                    while (iterator.hasNext()) {
-                        Entity entity = (Entity) iterator.next();
-
+                    for (Entity entity : list) {
                         if (!(entity instanceof Player) && !(entity instanceof IronGolem) && !(entity instanceof AbstractMinecart) && !this.isVehicle() && !entity.isPassenger()) {
                             // CraftBukkit start
                             VehicleEntityCollisionEvent collisionEvent = new VehicleEntityCollisionEvent(vehicle, entity.getBukkitEntity());
@@ -424,11 +425,7 @@ public abstract class AbstractMinecart extends VehicleEntity {
                     }
                 }
             } else {
-                Iterator iterator1 = this.level().getEntities(this, this.getBoundingBox().inflate(0.20000000298023224D, 0.0D, 0.20000000298023224D)).iterator();
-
-                while (iterator1.hasNext()) {
-                    Entity entity1 = (Entity) iterator1.next();
-
+                for (Entity entity1 : this.level().getEntities(this, this.getBoundingBox().inflate(0.20000000298023224D, 0.0D, 0.20000000298023224D))) {
                     if (!this.hasPassenger(entity1) && entity1.isPushable() && entity1 instanceof AbstractMinecart) {
                         // CraftBukkit start
                         VehicleEntityCollisionEvent collisionEvent = new VehicleEntityCollisionEvent(vehicle, entity1.getBukkitEntity());
@@ -442,6 +439,8 @@ public abstract class AbstractMinecart extends VehicleEntity {
                     }
                 }
             }
+            }
+            // Leaf end
 
             this.updateInWaterStateAndDoFluidPushing();
             if (this.isInLava()) {
diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index ff05efe0b78defe3d25905b6a2984bdb646fcff3..820f5dc02f89a54fab00942a3eaa72f006b3bd89 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -1572,12 +1572,14 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         return this.getChunk(chunkX, chunkZ, ChunkStatus.FULL, false);
     }
 
+    // Leaf start - Optimize predicate call
     @Override
-    public List<Entity> getEntities(@Nullable Entity except, AABB box, Predicate<? super Entity> predicate) {
+    public List<Entity> getEntities(@Nullable Entity except, AABB box, @Nullable Predicate<? super Entity> predicate) {
         List<Entity> list = Lists.newArrayList();
-        ((ServerLevel)this).getEntityLookup().getEntities(except, box, list, predicate); // Paper - optimise this call
-        return list;
+        ((ServerLevel) this).getEntityLookup().getEntities(except, box, list, null); // Paper - optimise this call
+        return predicate != null ? list.stream().filter(predicate).toList() : list;
     }
+    // Leaf end
 
     @Override
     public <T extends Entity> List<T> getEntities(EntityTypeTest<Entity, T> filter, AABB box, Predicate<? super T> predicate) {
diff --git a/src/main/java/org/dreeam/leaf/config/modules/opt/OptimizeMinecart.java b/src/main/java/org/dreeam/leaf/config/modules/opt/OptimizeMinecart.java
new file mode 100644
index 0000000000000000000000000000000000000000..a891454eb9b83d50ef3e8914efbb013f88a6b3fd
--- /dev/null
+++ b/src/main/java/org/dreeam/leaf/config/modules/opt/OptimizeMinecart.java
@@ -0,0 +1,28 @@
+package org.dreeam.leaf.config.modules.opt;
+
+import org.dreeam.leaf.config.ConfigInfo;
+import org.dreeam.leaf.config.EnumConfigCategory;
+import org.dreeam.leaf.config.IConfigModule;
+
+public class OptimizeMinecart implements IConfigModule {
+
+    @Override
+    public EnumConfigCategory getCategory() {
+        return EnumConfigCategory.PERFORMANCE;
+    }
+
+    @Override
+    public String getBaseName() {
+        return "optimize_minecart";
+    }
+
+    @ConfigInfo(baseName = "enabled", comments = """
+            Enable this feature to handle large amount of stacked Minecart better.
+            By skipping tick collisions to reduce expense getting entities list 
+            and bukkit event calls, useful for the anarchy server.
+            """)
+    public static boolean enabled = false;
+
+    @ConfigInfo(baseName = "skip-tick-count")
+    public static int skipTickCount = 30;
+}