From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: CullanP <cullanpage@gmail.com>
Date: Thu, 3 Mar 2016 02:13:38 -0600
Subject: [PATCH] Avoid hopper searches if there are no items

Hoppers searching for items and minecarts is the most expensive part of hopper ticking.
We keep track of the number of minecarts and items in a chunk.
If there are no items in the chunk, we skip searching for items.
If there are no minecarts in the chunk, we skip searching for them.

Usually hoppers aren't near items, so we can skip most item searches.
And since minecart hoppers are used _very_ rarely near we can avoid alot of searching there.

Combined, this adds up a lot.

diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 91bd27148f5b699b72d56844ded76e0e25e2693c..a4f446eff2a9e7f8ab99b156d0efe45d60e6c575 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -991,7 +991,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                 }
             }
 
-        });
+        }, predicate == net.minecraft.world.entity.EntitySelector.CONTAINER_ENTITY_SELECTOR); // Paper
         return list;
     }
 
diff --git a/src/main/java/net/minecraft/world/level/entity/EntitySection.java b/src/main/java/net/minecraft/world/level/entity/EntitySection.java
index 9a7b2602c2549dd03ad097c4a922a10a5e869645..5342eafe25614d262eeb39fa517a242e27d998f6 100644
--- a/src/main/java/net/minecraft/world/level/entity/EntitySection.java
+++ b/src/main/java/net/minecraft/world/level/entity/EntitySection.java
@@ -12,6 +12,10 @@ public class EntitySection<T> {
     protected static final Logger LOGGER = LogManager.getLogger();
     private final ClassInstanceMultiMap<T> storage;
     private Visibility chunkStatus;
+    // Paper start - track number of items and minecarts
+    public int itemCount;
+    public int inventoryEntityCount;
+    // Paper end
 
     public EntitySection(Class<T> entityClass, Visibility status) {
         this.chunkStatus = status;
@@ -19,10 +23,24 @@ public class EntitySection<T> {
     }
 
     public void add(T obj) {
+        // Paper start
+        if (obj instanceof net.minecraft.world.entity.item.ItemEntity) {
+            this.itemCount++;
+        } else if (obj instanceof net.minecraft.world.Container) {
+            this.inventoryEntityCount++;
+        }
+        // Paper end
         this.storage.add(obj);
     }
 
     public boolean remove(T obj) {
+        // Paper start
+        if (obj instanceof net.minecraft.world.entity.item.ItemEntity) {
+            this.itemCount--;
+        } else if (obj instanceof net.minecraft.world.Container) {
+            this.inventoryEntityCount--;
+        }
+        // Paper end
         return this.storage.remove(obj);
     }
 
@@ -39,7 +57,7 @@ public class EntitySection<T> {
         for(T object : this.storage.find(type.getBaseClass())) {
             U object2 = (U)type.tryCast(object);
             if (object2 != null && filter.test(object2)) {
-                action.accept((T)object2);
+                action.accept(object2); // Paper - decompile fix
             }
         }
 
diff --git a/src/main/java/net/minecraft/world/level/entity/EntitySectionStorage.java b/src/main/java/net/minecraft/world/level/entity/EntitySectionStorage.java
index 067138e3983959347d19754e668bb7a1f702bad0..24552500307c42f9f3dc5c4d9ba73a84a787423a 100644
--- a/src/main/java/net/minecraft/world/level/entity/EntitySectionStorage.java
+++ b/src/main/java/net/minecraft/world/level/entity/EntitySectionStorage.java
@@ -105,7 +105,7 @@ public class EntitySectionStorage<T extends EntityAccess> {
 
     public LongSet getAllChunksWithExistingSections() {
         LongSet longSet = new LongOpenHashSet();
-        this.sections.keySet().forEach((sectionPos) -> {
+        this.sections.keySet().forEach((java.util.function.LongConsumer) (sectionPos) -> { // Paper - decompile fix
             longSet.add(getChunkKeyFromSectionKey(sectionPos));
         });
         return longSet;
@@ -118,13 +118,20 @@ public class EntitySectionStorage<T extends EntityAccess> {
     }
 
     public void getEntities(AABB box, Consumer<T> action) {
+        // Paper start
+        this.getEntities(box, action, false);
+    }
+    public void getEntities(AABB box, Consumer<T> action, boolean isContainerSearch) {
+        // Paper end
         this.forEachAccessibleSection(box, (entitySection) -> {
+            if (isContainerSearch && entitySection.inventoryEntityCount <= 0) return; // Paper
             entitySection.getEntities(createBoundingBoxCheck(box), action);
         });
     }
 
     public <U extends T> void getEntities(EntityTypeTest<T, U> filter, AABB box, Consumer<U> action) {
         this.forEachAccessibleSection(box, (entitySection) -> {
+            if (filter.getBaseClass() == net.minecraft.world.entity.item.ItemEntity.class && entitySection.itemCount <= 0) return; // Paper
             entitySection.getEntities(filter, createBoundingBoxCheck(box), action);
         });
     }
diff --git a/src/main/java/net/minecraft/world/level/entity/LevelEntityGetter.java b/src/main/java/net/minecraft/world/level/entity/LevelEntityGetter.java
index 9723a0ad61548c8c6c4c5ef20a150d5b17d80afd..da1ad0b2679e392ed81b50c15f012c63cb5c939e 100644
--- a/src/main/java/net/minecraft/world/level/entity/LevelEntityGetter.java
+++ b/src/main/java/net/minecraft/world/level/entity/LevelEntityGetter.java
@@ -17,6 +17,7 @@ public interface LevelEntityGetter<T extends EntityAccess> {
     <U extends T> void get(EntityTypeTest<T, U> filter, Consumer<U> action);
 
     void get(AABB box, Consumer<T> action);
+    void get(AABB box, Consumer<T> action, boolean isContainerSearch); // Paper
 
     <U extends T> void get(EntityTypeTest<T, U> filter, AABB box, Consumer<U> action);
 }
diff --git a/src/main/java/net/minecraft/world/level/entity/LevelEntityGetterAdapter.java b/src/main/java/net/minecraft/world/level/entity/LevelEntityGetterAdapter.java
index d5129c12c79eb6fe6b7e5f8eed4d24226423f5fd..3b13f6ea36a3bfecabe09221eb5c48dddab119db 100644
--- a/src/main/java/net/minecraft/world/level/entity/LevelEntityGetterAdapter.java
+++ b/src/main/java/net/minecraft/world/level/entity/LevelEntityGetterAdapter.java
@@ -38,7 +38,13 @@ public class LevelEntityGetterAdapter<T extends EntityAccess> implements LevelEn
 
     @Override
     public void get(AABB box, Consumer<T> action) {
-        this.sectionStorage.getEntities(box, action);
+        // Paper start
+        this.get(box, action, false);
+    }
+    @Override
+    public void get(AABB box, Consumer<T> action, boolean isContainerSearch) {
+        this.sectionStorage.getEntities(box, action, isContainerSearch);
+        // Paper end
     }
 
     @Override