Paper/Spigot-Server-Patches/0681-do-not-create-unnecessary-copies-of-passenger-list.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: lukas81298 <lukas81298@gmail.com>
Date: Sun, 13 Dec 2020 13:42:55 +0100
Subject: [PATCH] do not create unnecessary copies of passenger list


diff --git a/src/main/java/net/minecraft/network/protocol/game/PacketPlayOutMount.java b/src/main/java/net/minecraft/network/protocol/game/PacketPlayOutMount.java
index edc6fff87c4abad2c123b1a46d6e5b792602b3be..5e739b26b6b5490b2c7651d3e9ff8649e776137e 100644
--- a/src/main/java/net/minecraft/network/protocol/game/PacketPlayOutMount.java
+++ b/src/main/java/net/minecraft/network/protocol/game/PacketPlayOutMount.java
@@ -15,7 +15,7 @@ public class PacketPlayOutMount implements Packet<PacketListenerPlayOut> {
 
     public PacketPlayOutMount(Entity entity) {
         this.a = entity.getId();
-        List<Entity> list = entity.getPassengers();
+        List<Entity> list = entity.passengers; // Paper - do not create a copy of the list
 
         this.b = new int[list.size()];
 
diff --git a/src/main/java/net/minecraft/server/level/EntityTrackerEntry.java b/src/main/java/net/minecraft/server/level/EntityTrackerEntry.java
index aa5ba862f18ff706f11b0b26cea55a904a5a9473..f65eb0168ed365e5c1b490c56ec84e3b7ff87c1d 100644
--- a/src/main/java/net/minecraft/server/level/EntityTrackerEntry.java
+++ b/src/main/java/net/minecraft/server/level/EntityTrackerEntry.java
@@ -103,10 +103,10 @@ public class EntityTrackerEntry {
 
     public final void tick() { this.a(); } // Paper - OBFHELPER
     public void a() {
-        List<Entity> list = this.tracker.getPassengers();
+        List<Entity> list = this.tracker.passengers; // Paper - do not copy list
 
         if (!list.equals(this.p)) {
-            this.p = list;
+            this.p = com.google.common.collect.ImmutableList.copyOf(list); // Paper - only copy list if something has changed
             this.broadcastIncludingSelf(new PacketPlayOutMount(this.tracker)); // CraftBukkit
         }
 
@@ -377,7 +377,7 @@ public class EntityTrackerEntry {
             }
         }
 
-        if (!this.tracker.getPassengers().isEmpty()) {
+        if (!this.tracker.passengers.isEmpty()) { // Paper - do not create copy of list
             consumer.accept(new PacketPlayOutMount(this.tracker));
         }
 
diff --git a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
index f3f906d8ffa195b100d5bd2d232ae8489d48d60d..5e5545f16daf20682e7984e1b4d3ffa0151ad1c1 100644
--- a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
@@ -2297,7 +2297,7 @@ Sections go from 0..16. Now whenever a section is not empty, it can potentially
                 list.add(entity);
             }
 
-            if (!entity.getPassengers().isEmpty()) {
+            if (!entity.passengers.isEmpty()) { // Paper - do not copy list
                 list1.add(entity);
             }
         }
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index bb3211d0177f569b018852fc2a9094431e952b02..f88af0aa6a86d7d2f7e12b710fce4d37c9ee421f 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -2223,7 +2223,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
     }
 
     protected boolean q(Entity entity) {
-        return this.getPassengers().size() < 1;
+        return this.passengers.size() < 1; // Paper - do not copy list
     }
 
     public final float getCollisionBorderSize() { return bg(); } // Paper - OBFHELPER
@@ -2319,7 +2319,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
     }
 
     public boolean isVehicle() {
-        return !this.getPassengers().isEmpty();
+        return !this.passengers.isEmpty(); // Paper - do not copy list
     }
 
     public boolean bt() {
@@ -3131,7 +3131,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
     }
 
     public boolean w(Entity entity) {
-        Iterator iterator = this.getPassengers().iterator();
+        Iterator iterator = this.passengers.iterator(); // Paper - do not copy list
 
         Entity entity1;
 
@@ -3147,7 +3147,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
     }
 
     public boolean a(Class<? extends Entity> oclass) {
-        Iterator iterator = this.getPassengers().iterator();
+        Iterator iterator = this.passengers.iterator(); // Paper - do not copy list
 
         Entity entity;
 
@@ -3164,7 +3164,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
 
     public Collection<Entity> getAllPassengers() {
         Set<Entity> set = Sets.newHashSet();
-        Iterator iterator = this.getPassengers().iterator();
+        Iterator iterator = this.passengers.iterator(); // Paper - do not copy list
 
         while (iterator.hasNext()) {
             Entity entity = (Entity) iterator.next();
@@ -3190,7 +3190,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
     private void a(boolean flag, Set<Entity> set) {
         Entity entity;
 
-        for (Iterator iterator = this.getPassengers().iterator(); iterator.hasNext(); entity.a(flag, set)) {
+        for (Iterator iterator = this.passengers.iterator(); iterator.hasNext(); entity.a(flag, set)) { // Paper - do not copy list
             entity = (Entity) iterator.next();
             if (!flag || EntityPlayer.class.isAssignableFrom(entity.getClass())) {
                 set.add(entity);
diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/PathfinderGoalTame.java b/src/main/java/net/minecraft/world/entity/ai/goal/PathfinderGoalTame.java
index ec51a5532576ce25465bacf61c716ddaffca514e..d285f5aa66fa81a2f56920c05afb4506cb82fa54 100644
--- a/src/main/java/net/minecraft/world/entity/ai/goal/PathfinderGoalTame.java
+++ b/src/main/java/net/minecraft/world/entity/ai/goal/PathfinderGoalTame.java
@@ -52,7 +52,7 @@ public class PathfinderGoalTame extends PathfinderGoal {
     @Override
     public void e() {
         if (!this.entity.isTamed() && this.entity.getRandom().nextInt(50) == 0) {
-            Entity entity = (Entity) this.entity.getPassengers().get(0);
+            Entity entity = this.entity.passengers.isEmpty() ? null : this.entity.passengers.get(0); // Paper - do not copy list, fixed array out of bounds exception as well
 
             if (entity == null) {
                 return;
diff --git a/src/main/java/net/minecraft/world/entity/animal/EntityPig.java b/src/main/java/net/minecraft/world/entity/animal/EntityPig.java
index d6e1697f64e60f2a567288c604a1690159955f37..676ca381a5e111fc15f319e73504e4e60dbf0d2b 100644
--- a/src/main/java/net/minecraft/world/entity/animal/EntityPig.java
+++ b/src/main/java/net/minecraft/world/entity/animal/EntityPig.java
@@ -86,7 +86,7 @@ public class EntityPig extends EntityAnimal implements ISteerable, ISaddleable {
     @Nullable
     @Override
     public Entity getRidingPassenger() {
-        return this.getPassengers().isEmpty() ? null : (Entity) this.getPassengers().get(0);
+        return this.passengers.isEmpty() ? null : (Entity) this.passengers.get(0); // Paper - do not copy list
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseAbstract.java b/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseAbstract.java
index d678e3164ecdb7f0c600597bcb39d1054dfbc4b2..1e41c45af6dbcf097d7d6104e63db637f199301a 100644
--- a/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseAbstract.java
+++ b/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseAbstract.java
@@ -972,7 +972,7 @@ public abstract class EntityHorseAbstract extends EntityAnimal implements IInven
     @Nullable
     @Override
     public Entity getRidingPassenger() {
-        return this.getPassengers().isEmpty() ? null : (Entity) this.getPassengers().get(0);
+        return this.passengers.isEmpty() ? null : (Entity) this.passengers.get(0); // Paper - do not copy list
     }
 
     @Nullable
diff --git a/src/main/java/net/minecraft/world/entity/monster/EntityRavager.java b/src/main/java/net/minecraft/world/entity/monster/EntityRavager.java
index 7781386da593a1c4f3ad7e7e8761767dda7cb66c..16d5cae64887b82e67eeb61ccb714e6125ff0c09 100644
--- a/src/main/java/net/minecraft/world/entity/monster/EntityRavager.java
+++ b/src/main/java/net/minecraft/world/entity/monster/EntityRavager.java
@@ -134,7 +134,7 @@ public class EntityRavager extends EntityRaider {
     @Nullable
     @Override
     public Entity getRidingPassenger() {
-        return this.getPassengers().isEmpty() ? null : (Entity) this.getPassengers().get(0);
+        return this.passengers.isEmpty() ? null : (Entity) this.passengers.get(0); // Paper - do not copy list
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/EntityBoat.java b/src/main/java/net/minecraft/world/entity/vehicle/EntityBoat.java
index 5ae7620be7b0b5fba6aab8173aed45dc28bf36e3..0e3fcf5facdac7f5d2d509f20cb45d5de38f72d4 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/EntityBoat.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/EntityBoat.java
@@ -316,7 +316,7 @@ public class EntityBoat extends Entity {
         super.tick();
         this.r();
         if (this.cs()) {
-            if (this.getPassengers().isEmpty() || !(this.getPassengers().get(0) instanceof EntityHuman)) {
+            if (this.passengers.isEmpty() || !(this.passengers.get(0) instanceof EntityHuman)) { // Paper - do not copy list
                 this.a(false, false);
             }
 
@@ -379,7 +379,7 @@ public class EntityBoat extends Entity {
                 Entity entity = (Entity) list.get(j);
 
                 if (!entity.w(this)) {
-                    if (flag && this.getPassengers().size() < 2 && !entity.isPassenger() && entity.getWidth() < this.getWidth() && entity instanceof EntityLiving && !(entity instanceof EntityWaterAnimal) && !(entity instanceof EntityHuman)) {
+                    if (flag && this.passengers.size() < 2 && !entity.isPassenger() && entity.getWidth() < this.getWidth() && entity instanceof EntityLiving && !(entity instanceof EntityWaterAnimal) && !(entity instanceof EntityHuman)) { // Paper - do not copy passenger list
                         entity.startRiding(this);
                     } else {
                         this.collide(entity);
@@ -726,8 +726,8 @@ public class EntityBoat extends Entity {
             float f = 0.0F;
             float f1 = (float) ((this.dead ? 0.009999999776482582D : this.bc()) + entity.bb());
 
-            if (this.getPassengers().size() > 1) {
-                int i = this.getPassengers().indexOf(entity);
+            if (this.passengers.size() > 1) { // Paper - do not copy list
+                int i = this.passengers.indexOf(entity); // Paper - do not copy list
 
                 if (i == 0) {
                     f = 0.2F;
@@ -746,7 +746,7 @@ public class EntityBoat extends Entity {
             entity.yaw += this.ak;
             entity.setHeadRotation(entity.getHeadRotation() + this.ak);
             this.a(entity);
-            if (entity instanceof EntityAnimal && this.getPassengers().size() > 1) {
+            if (entity instanceof EntityAnimal && this.passengers.size() > 1) { // Paper - do not copy list
                 int j = entity.getId() % 2 == 0 ? 90 : 270;
 
                 entity.n(((EntityAnimal) entity).aA + (float) j);
@@ -906,13 +906,13 @@ public class EntityBoat extends Entity {
 
     @Override
     protected boolean q(Entity entity) {
-        return this.getPassengers().size() < 2 && !this.a((Tag) TagsFluid.WATER);
+        return this.passengers.size() < 2 && !this.a((Tag) TagsFluid.WATER); // Paper - do not copy list
     }
 
     @Nullable
     @Override
     public Entity getRidingPassenger() {
-        List<Entity> list = this.getPassengers();
+        List<Entity> list = this.passengers; // Paper - do not copy list
 
         return list.isEmpty() ? null : (Entity) list.get(0);
     }
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/EntityMinecartAbstract.java b/src/main/java/net/minecraft/world/entity/vehicle/EntityMinecartAbstract.java
index c79474ffb455bb87bfdd98bc68b3dc8dfcdca45e..f2b905e5689ee419e9d83bb4ca671ef44ccb031f 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/EntityMinecartAbstract.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/EntityMinecartAbstract.java
@@ -560,7 +560,7 @@ public abstract class EntityMinecartAbstract extends Entity {
 
         vec3d1 = new Vec3D(d8 * d4 / d6, vec3d1.y, d8 * d5 / d6);
         this.setMot(vec3d1);
-        Entity entity = this.getPassengers().isEmpty() ? null : (Entity) this.getPassengers().get(0);
+        Entity entity = this.passengers.isEmpty() ? null : (Entity) this.passengers.get(0); // Paper - do not copy list
 
         if (entity instanceof EntityHuman) {
             Vec3D vec3d2 = entity.getMot();