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 8e5e773fffcb17d20328903d1b1fc9d9e0aefa3e..11a02c8259a039bbe229c5626055bceef9308b5a 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -965,7 +965,7 @@ 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 524f3c42964eb83c9109bcc548a1075f1e295411..e9aee7d11798c3bd990466f101e9e342686de11c 100644
--- a/src/main/java/net/minecraft/world/level/entity/EntitySection.java
+++ b/src/main/java/net/minecraft/world/level/entity/EntitySection.java
@@ -13,6 +13,10 @@ public class EntitySection<T extends EntityAccess> {
     private static final Logger LOGGER = LogUtils.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;
@@ -20,10 +24,24 @@ public class EntitySection<T extends EntityAccess> {
     }
 
     public void add(T entity) {
+        // Paper start
+        if (entity instanceof net.minecraft.world.entity.item.ItemEntity) {
+            this.itemCount++;
+        } else if (entity instanceof net.minecraft.world.Container) {
+            this.inventoryEntityCount++;
+        }
+        // Paper end
         this.storage.add(entity);
     }
 
     public boolean remove(T entity) {
+        // Paper start
+        if (entity instanceof net.minecraft.world.entity.item.ItemEntity) {
+            this.itemCount--;
+        } else if (entity instanceof net.minecraft.world.Container) {
+            this.inventoryEntityCount--;
+        }
+        // Paper end
         return this.storage.remove(entity);
     }
 
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 4c1e7c219e1ca153be4423347bd239ebaec4a31d..f54ca6383298848b2ee7108c41fcea593f924881 100644
--- a/src/main/java/net/minecraft/world/level/entity/EntitySectionStorage.java
+++ b/src/main/java/net/minecraft/world/level/entity/EntitySectionStorage.java
@@ -112,13 +112,20 @@ 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.forEachAccessibleNonEmptySection(box, (section) -> {
+            if (isContainerSearch && section.inventoryEntityCount <= 0) return; // Paper
             section.getEntities(box, action);
         });
     }
 
     public <U extends T> void getEntities(EntityTypeTest<T, U> filter, AABB box, Consumer<U> action) {
         this.forEachAccessibleNonEmptySection(box, (section) -> {
+            if (filter.getBaseClass() == net.minecraft.world.entity.item.ItemEntity.class && section.itemCount <= 0) return; // Paper
             section.getEntities(filter, 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
