PaperMC/patches/server/0726-Remove-streams-for-villager-AI.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Thu, 27 Aug 2020 20:51:40 -0700
Subject: [PATCH] Remove streams for villager AI


diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java b/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java
index b45c4f50705f80163d44d9e588f86a5770f5be38..10cbb80c7cd9ba30150d8d935c0d115719c35509 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java
@@ -52,7 +52,7 @@ public class GateBehavior<E extends LivingEntity> implements BehaviorControl<E>
         if (this.hasRequiredMemories(entity)) {
             this.status = Behavior.Status.RUNNING;
             this.orderPolicy.apply(this.behaviors);
-            this.runningPolicy.apply(this.behaviors.stream(), world, entity, time);
+            this.runningPolicy.apply(this.behaviors.entries, world, entity, time);
             return true;
         } else {
             return false;
@@ -61,11 +61,13 @@ public class GateBehavior<E extends LivingEntity> implements BehaviorControl<E>
 
     @Override
     public final void tickOrStop(ServerLevel world, E entity, long time) {
-        this.behaviors.stream().filter((task) -> {
-            return task.getStatus() == Behavior.Status.RUNNING;
-        }).forEach((task) -> {
-            task.tickOrStop(world, entity, time);
-        });
+        // Paper start
+        for (BehaviorControl<? super E> task : this.behaviors) {
+            if (task.getStatus() == Behavior.Status.RUNNING) {
+                task.tickOrStop(world, entity, time);
+            }
+        }
+        // Paper end
         if (this.behaviors.stream().noneMatch((task) -> {
             return task.getStatus() == Behavior.Status.RUNNING;
         })) {
@@ -77,11 +79,11 @@ public class GateBehavior<E extends LivingEntity> implements BehaviorControl<E>
     @Override
     public final void doStop(ServerLevel world, E entity, long time) {
         this.status = Behavior.Status.STOPPED;
-        this.behaviors.stream().filter((task) -> {
-            return task.getStatus() == Behavior.Status.RUNNING;
-        }).forEach((task) -> {
-            task.doStop(world, entity, time);
-        });
+        for (BehaviorControl<? super E> behavior : this.behaviors) {
+            if (behavior.getStatus() == Behavior.Status.RUNNING) {
+                behavior.doStop(world, entity, time);
+            }
+        }
         this.exitErasedMemories.forEach(entity.getBrain()::eraseMemory);
     }
 
@@ -117,25 +119,31 @@ public class GateBehavior<E extends LivingEntity> implements BehaviorControl<E>
     public static enum RunningPolicy {
         RUN_ONE {
             @Override
-            public <E extends LivingEntity> void apply(Stream<BehaviorControl<? super E>> tasks, ServerLevel world, E entity, long time) {
-                tasks.filter((task) -> {
-                    return task.getStatus() == Behavior.Status.STOPPED;
-                }).filter((task) -> {
-                    return task.tryStart(world, entity, time);
-                }).findFirst();
+            // Paper start - remove streams
+            public <E extends LivingEntity> void apply(List<ShufflingList.WeightedEntry<BehaviorControl<? super E>>> tasks, ServerLevel world, E entity, long time) {
+                for (ShufflingList.WeightedEntry<BehaviorControl<? super E>> task : tasks) {
+                    final BehaviorControl<? super E> behavior = task.getData();
+                    if (behavior.getStatus() == Behavior.Status.STOPPED && behavior.tryStart(world, entity, time)) {
+                        break;
+                    }
+                }
+                // Paper end - remove streams
             }
         },
         TRY_ALL {
             @Override
-            public <E extends LivingEntity> void apply(Stream<BehaviorControl<? super E>> tasks, ServerLevel world, E entity, long time) {
-                tasks.filter((task) -> {
-                    return task.getStatus() == Behavior.Status.STOPPED;
-                }).forEach((task) -> {
-                    task.tryStart(world, entity, time);
-                });
+            // Paper start - remove streams
+            public <E extends LivingEntity> void apply(List<ShufflingList.WeightedEntry<BehaviorControl<? super E>>> tasks, ServerLevel world, E entity, long time) {
+                for (ShufflingList.WeightedEntry<BehaviorControl<? super E>> task : tasks) {
+                    final BehaviorControl<? super E> behavior = task.getData();
+                    if (behavior.getStatus() == Behavior.Status.STOPPED) {
+                        behavior.tryStart(world, entity, time);
+                    }
+                }
+                // Paper end - remove streams
             }
         };
 
-        public abstract <E extends LivingEntity> void apply(Stream<BehaviorControl<? super E>> tasks, ServerLevel world, E entity, long time);
+        public abstract <E extends LivingEntity> void apply(List<ShufflingList.WeightedEntry<BehaviorControl<? super E>>> tasks, ServerLevel world, E entity, long time); // Paper - remove streams
     }
 }
diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java b/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java
index 731ef21dbbd25d6924717de42f4569a9b5935643..fe3ab3d388f0481fb0db06b7f730f868dbf8e8a5 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java
@@ -14,7 +14,7 @@ import java.util.stream.Stream;
 import net.minecraft.util.RandomSource;
 
 public class ShufflingList<U> implements Iterable<U> {
-    protected final List<ShufflingList.WeightedEntry<U>> entries;
+    public final List<ShufflingList.WeightedEntry<U>> entries; // Paper - public
     private final RandomSource random = RandomSource.create();
     private final boolean isUnsafe; // Paper
 
diff --git a/src/main/java/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java b/src/main/java/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java
index 1dfcc5cba6ffb463acf161a23fff1ca452184290..2c4517850a9692f1c2b1332b58e8312fe1166772 100644
--- a/src/main/java/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java
+++ b/src/main/java/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java
@@ -25,13 +25,16 @@ public class NearestItemSensor extends Sensor<Mob> {
     protected void doTick(ServerLevel world, Mob entity) {
         Brain<?> brain = entity.getBrain();
         List<ItemEntity> list = world.getEntitiesOfClass(ItemEntity.class, entity.getBoundingBox().inflate(32.0D, 16.0D, 32.0D), (itemEntity) -> {
-            return true;
+            return itemEntity.closerThan(entity, 9.0D) && entity.wantsToPickUp(itemEntity.getItem()); // Paper - move predicate into getEntities
         });
-        list.sort(Comparator.comparingDouble(entity::distanceToSqr));
+        list.sort((e1, e2) -> Double.compare(entity.distanceToSqr(e1), entity.distanceToSqr(e2))); // better to take the sort perf hit than using line of sight more than we need to.
+        // Paper start - remove streams
         // Paper start - remove streams in favour of lists
         ItemEntity nearest = null;
-        for (ItemEntity entityItem : list) {
-            if (entity.wantsToPickUp(entityItem.getItem()) && entityItem.closerThan(entity, 32.0D) && entity.hasLineOfSight(entityItem)) {
+        for (int i = 0; i < list.size(); i++) {
+            ItemEntity entityItem = list.get(i);
+            if (entity.hasLineOfSight(entityItem)) {
+                // Paper end - remove streams
                 nearest = entityItem;
                 break;
             }
diff --git a/src/main/java/net/minecraft/world/entity/ai/sensing/PlayerSensor.java b/src/main/java/net/minecraft/world/entity/ai/sensing/PlayerSensor.java
index 312775d0430f793720211dc29bb293503e799d11..75d9c4f011b5a97def215784c92bb57bbb35d06b 100644
--- a/src/main/java/net/minecraft/world/entity/ai/sensing/PlayerSensor.java
+++ b/src/main/java/net/minecraft/world/entity/ai/sensing/PlayerSensor.java
@@ -21,25 +21,30 @@ public class PlayerSensor extends Sensor<LivingEntity> {
 
     @Override
     protected void doTick(ServerLevel world, LivingEntity entity) {
-        List<Player> players = new java.util.ArrayList<>(world.players());
-        players.removeIf(player -> !EntitySelector.NO_SPECTATORS.test(player) || !entity.closerThan(player, 16.0D));
-        players.sort(Comparator.comparingDouble(entity::distanceTo));
+        // Paper start - remove streams
+        List<Player> players = (List)world.getNearbyPlayers(entity, entity.getX(), entity.getY(), entity.getZ(), 16.0D, EntitySelector.NO_SPECTATORS);
+        players.sort((e1, e2) -> Double.compare(entity.distanceToSqr(e1), entity.distanceToSqr(e2)));
         Brain<?> brain = entity.getBrain();
 
         brain.setMemory(MemoryModuleType.NEAREST_PLAYERS, players);
 
-        Player nearest = null, nearestTargetable = null;
-        for (Player player : players) {
-            if (Sensor.isEntityTargetable(entity, player)) {
-                if (nearest == null) nearest = player;
-                if (Sensor.isEntityAttackable(entity, player)) {
-                    nearestTargetable = player;
-                    break; // Both variables are assigned, no reason to loop further
-                }
+        Player firstTargetable = null;
+        Player firstAttackable = null;
+        for (int index = 0, len = players.size(); index < len; ++index) {
+            Player player = players.get(index);
+            if (firstTargetable == null && isEntityTargetable(entity, player)) {
+                firstTargetable = player;
+            }
+            if (firstAttackable == null && isEntityAttackable(entity, player)) {
+                firstAttackable = player;
+            }
+
+            if (firstAttackable != null && firstTargetable != null) {
+                break;
             }
         }
-        brain.setMemory(MemoryModuleType.NEAREST_VISIBLE_PLAYER, nearest);
-        brain.setMemory(MemoryModuleType.NEAREST_VISIBLE_ATTACKABLE_PLAYER, nearestTargetable);
-        // Paper end
+        brain.setMemory(MemoryModuleType.NEAREST_VISIBLE_PLAYER, firstTargetable);
+        brain.setMemory(MemoryModuleType.NEAREST_VISIBLE_ATTACKABLE_PLAYER, Optional.ofNullable(firstAttackable));
+        // Paper end - remove streams
     }
 }