Paper/patches/server/0779-Remove-streams-for-villager-AI.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <spottedleaf@spottedleaf.dev>
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 e644bdd3a6f7c09a44149da03587b796674fa568..c67c448e0d8bdd788b94189651304110694c95da 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
@@ -30,11 +30,19 @@ public class GateBehavior<E extends LivingEntity> extends Behavior<E> {
 
     @Override
     protected boolean canStillUse(ServerLevel world, E entity, long time) {
-        return this.behaviors.stream().filter((task) -> {
-            return task.getStatus() == Behavior.Status.RUNNING;
-        }).anyMatch((task) -> {
-            return task.canStillUse(world, entity, time);
-        });
+        // Paper start - remove streams
+        List<ShufflingList.WeightedEntry<Behavior<? super E>>> entries = this.behaviors.entries;
+        for (int i = 0; i < entries.size(); i++) {
+            ShufflingList.WeightedEntry<Behavior<? super E>> entry = entries.get(i);
+            Behavior<? super E> behavior = entry.getData();
+            if (behavior.getStatus() == Status.RUNNING) {
+                if (behavior.canStillUse(world, entity, time)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+        // Paper end - remove streams
     }
 
     @Override
@@ -45,25 +53,35 @@ public class GateBehavior<E extends LivingEntity> extends Behavior<E> {
     @Override
     protected void start(ServerLevel world, E entity, long time) {
         this.orderPolicy.apply(this.behaviors);
-        this.runningPolicy.apply(this.behaviors.stream(), world, entity, time);
+        this.runningPolicy.apply(this.behaviors.entries, world, entity, time); // Paper - remove streams
     }
 
     @Override
     protected void tick(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 - remove streams
+        List<ShufflingList.WeightedEntry<Behavior<? super E>>> entries = this.behaviors.entries;
+        for (int i = 0; i < entries.size(); i++) {
+            ShufflingList.WeightedEntry<Behavior<? super E>> entry = entries.get(i);
+            Behavior<? super E> behavior = entry.getData();
+            if (behavior.getStatus() == Status.RUNNING) {
+                behavior.tickOrStop(world, entity, time);
+            }
+        }
+        // Paper end - remove streams
     }
 
     @Override
     protected void stop(ServerLevel world, E entity, long time) {
-        this.behaviors.stream().filter((task) -> {
-            return task.getStatus() == Behavior.Status.RUNNING;
-        }).forEach((task) -> {
-            task.doStop(world, entity, time);
-        });
+        // Paper start - remove streams
+        List<ShufflingList.WeightedEntry<Behavior<? super E>>> entries = this.behaviors.entries;
+        for (int i = 0; i < entries.size(); i++) {
+            ShufflingList.WeightedEntry<Behavior<? super E>> entry = entries.get(i);
+            Behavior<? super E> behavior = entry.getData();
+            if (behavior.getStatus() == Status.RUNNING) {
+                behavior.doStop(world, entity, time);
+            }
+        }
+        // Paper end - remove streams
         this.exitErasedMemories.forEach(entity.getBrain()::eraseMemory);
     }
 
@@ -94,25 +112,33 @@ public class GateBehavior<E extends LivingEntity> extends Behavior<E> {
     public static enum RunningPolicy {
         RUN_ONE {
             @Override
-            public <E extends LivingEntity> void apply(Stream<Behavior<? 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<Behavior<? super E>>> tasks, ServerLevel world, E entity, long time) {
+                for (int i = 0; i < tasks.size(); i++) {
+                    ShufflingList.WeightedEntry<Behavior<? super E>> task = tasks.get(i);
+                    Behavior<? super E> behavior = task.getData();
+                    if (behavior.getStatus() == Status.STOPPED && behavior.tryStart(world, entity, time)) {
+                        break;
+                    }
+                }
+                // Paper end - remove streams
             }
         },
         TRY_ALL {
             @Override
-            public <E extends LivingEntity> void apply(Stream<Behavior<? 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<Behavior<? super E>>> tasks, ServerLevel world, E entity, long time) {
+                for (int i = 0; i < tasks.size(); i++) {
+                    ShufflingList.WeightedEntry<Behavior<? super E>> task = tasks.get(i);
+                    Behavior<? super E> behavior = task.getData();
+                    if (behavior.getStatus() == Status.STOPPED) {
+                        behavior.tryStart(world, entity, time);
+                    }
+                }
+                // Paper end - remove streams
             }
         };
 
-        public abstract <E extends LivingEntity> void apply(Stream<Behavior<? super E>> tasks, ServerLevel world, E entity, long time);
+        public abstract <E extends LivingEntity> void apply(List<ShufflingList.WeightedEntry<Behavior<? 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 1bc34453933bc7590af45a5559a4fc75eb3e0c5c..204ca4fbd89bdadd902529f1f191df46fce3cace 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
@@ -12,7 +12,7 @@ import java.util.Random;
 import java.util.stream.Stream;
 
 public class ShufflingList<U> {
-    protected final List<ShufflingList.WeightedEntry<U>> entries;
+    public final List<ShufflingList.WeightedEntry<U>> entries; // Paper - public
     private final Random random = new Random();
     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 49f3b25d28072b61f5cc97260df61df892a58714..71f2692c83feafbb31f45427e6c738cb3881c82c 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
@@ -25,17 +25,20 @@ 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(8.0D, 4.0D, 8.0D), (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, 9.0D) && entity.hasLineOfSight(entityItem)) {
+        for (int i = 0; i < list.size(); i++) {
+            ItemEntity entityItem = list.get(i);
+            if (entity.hasLineOfSight(entityItem)) {
                 nearest = entityItem;
                 break;
             }
         }
+        // Paper end - remove streams
         brain.setMemory(MemoryModuleType.NEAREST_VISIBLE_WANTED_ITEM, Optional.ofNullable(nearest));
         // Paper end
     }
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
     }
 }