PaperMC/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/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index e87e1b04e13593f1efa4d1c59cb9e433f2b3c694..534238688be75c53058dcfeabcdf86d9c0504089 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -2138,7 +2138,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
 
     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
@@ -2234,7 +2234,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
 
     public boolean isVehicle() {
-        return !this.getPassengers().isEmpty();
+        return !this.passengers.isEmpty(); // Paper - do not copy list
     }
 
     public boolean bt() {
@@ -3046,7 +3046,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
 
     public boolean w(Entity entity) {
-        Iterator iterator = this.getPassengers().iterator();
+        Iterator iterator = this.passengers.iterator(); // Paper - do not copy list
 
         Entity entity1;
 
@@ -3062,7 +3062,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
 
     public boolean a(Class<? extends Entity> oclass) {
-        Iterator iterator = this.getPassengers().iterator();
+        Iterator iterator = this.passengers.iterator(); // Paper - do not copy list
 
         Entity entity;
 
@@ -3079,7 +3079,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
 
     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();
@@ -3105,7 +3105,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     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/server/EntityBoat.java b/src/main/java/net/minecraft/server/EntityBoat.java
index baa4a61114e7460c74027e1519332f0dd9582647..15ce9f90306d062f36d1651d7426813e897523bf 100644
--- a/src/main/java/net/minecraft/server/EntityBoat.java
+++ b/src/main/java/net/minecraft/server/EntityBoat.java
@@ -272,7 +272,7 @@ 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);
             }
 
@@ -335,7 +335,7 @@ 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);
@@ -682,8 +682,8 @@ 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;
@@ -702,7 +702,7 @@ 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);
@@ -862,13 +862,13 @@ 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/server/EntityHorseAbstract.java b/src/main/java/net/minecraft/server/EntityHorseAbstract.java
index 2a91f07ca9c4dc0cb3b5aef5c9c1db7f69773530..5f9ee870697de306f595120bec05ba98d2fcb534 100644
--- a/src/main/java/net/minecraft/server/EntityHorseAbstract.java
+++ b/src/main/java/net/minecraft/server/EntityHorseAbstract.java
@@ -910,7 +910,7 @@ 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/server/EntityMinecartAbstract.java b/src/main/java/net/minecraft/server/EntityMinecartAbstract.java
index 022dfdc5b6af4b243e7e4da8660e8e41d04e1a30..be859a1b41254b299a507d03e453dc8efee6f3dd 100644
--- a/src/main/java/net/minecraft/server/EntityMinecartAbstract.java
+++ b/src/main/java/net/minecraft/server/EntityMinecartAbstract.java
@@ -522,7 +522,7 @@ 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();
diff --git a/src/main/java/net/minecraft/server/EntityPig.java b/src/main/java/net/minecraft/server/EntityPig.java
index ee94c2827cfc53f7a37e61d8c1c0c30a52374cf8..01ca5983cade997b1f0d27fdf495c74c6daa0922 100644
--- a/src/main/java/net/minecraft/server/EntityPig.java
+++ b/src/main/java/net/minecraft/server/EntityPig.java
@@ -39,7 +39,7 @@ 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/server/EntityRavager.java b/src/main/java/net/minecraft/server/EntityRavager.java
index fd1ac7df68a0caebe35290cdf7a9c37519342b61..e78f158d9c682c60d42c17e0f171d492552e4079 100644
--- a/src/main/java/net/minecraft/server/EntityRavager.java
+++ b/src/main/java/net/minecraft/server/EntityRavager.java
@@ -93,7 +93,7 @@ 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/server/EntityTrackerEntry.java b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
index 3960a975e74ed81c45819fe5e0f01c6c18252982..f2a9396c2ec64c79391782249db7507f12a69a9e 100644
--- a/src/main/java/net/minecraft/server/EntityTrackerEntry.java
+++ b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
@@ -74,10 +74,10 @@ 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
         }
 
@@ -348,7 +348,7 @@ 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/PacketPlayOutMount.java b/src/main/java/net/minecraft/server/PacketPlayOutMount.java
index 1d495e53fb4330ac4235721238d09e7163b2cd20..c4387df2f5c66c350184407b7f5a4db80542d1f6 100644
--- a/src/main/java/net/minecraft/server/PacketPlayOutMount.java
+++ b/src/main/java/net/minecraft/server/PacketPlayOutMount.java
@@ -12,7 +12,7 @@ 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/PathfinderGoalTame.java b/src/main/java/net/minecraft/server/PathfinderGoalTame.java
index fc831dc26eaeab802d5fee456d5c662fe3f8bdfd..8757c6487a433b1fa5c46b50c559aeca82f84b8d 100644
--- a/src/main/java/net/minecraft/server/PathfinderGoalTame.java
+++ b/src/main/java/net/minecraft/server/PathfinderGoalTame.java
@@ -47,7 +47,7 @@ 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/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
index 49008cdec739b19409fdaf1b0ed806a6c0e93200..e16cd5da219e41f16f9c04fd95b79fe5cf10f6b8 100644
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
@@ -2252,7 +2252,7 @@ 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);
             }
         }