From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: JellySquid <jellysquid+atwork@protonmail.com>
Date: Fri, 31 Jul 2020 21:46:32 -0500
Subject: [PATCH] lithium MixinBiome

Original code by JellySquid, licensed under GNU Lesser General Public License v3.0
you can find the original code on https://github.com/jellysquid3/lithium-fabric/tree/1.16.x/fabric (Yarn mappings)

diff --git a/src/main/java/me/jellysquid/mods/lithium/common/util/collections/HashedList.java b/src/main/java/me/jellysquid/mods/lithium/common/util/collections/HashedList.java
new file mode 100644
index 0000000000000000000000000000000000000000..15cc7232e4edf6803e4b831ff094a748f95e1f9a
--- /dev/null
+++ b/src/main/java/me/jellysquid/mods/lithium/common/util/collections/HashedList.java
@@ -0,0 +1,171 @@
+package me.jellysquid.mods.lithium.common.util.collections;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Set;
+
+/**
+ * Wraps a {@link List} with a hash table which provides O(1) lookups for {@link Collection#contains(Object)}.
+ *
+ * @see <a href="https://github.com/jellysquid3/lithium-fabric/blob/1.16.x/fabric/src/main/java/me/jellysquid/mods/lithium/common/util/collections/HashedList.java">HashedList</a>
+ */
+public class HashedList<T> implements List<T> {
+    private final List<T> list;
+    private final Set<T> set;
+
+    private HashedList(List<T> list, Set<T> set) {
+        this.list = list;
+        this.set = set;
+    }
+
+    @Override
+    public int size() {
+        return this.list.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return this.list.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return this.set.contains(o);
+    }
+
+    @Override
+    public Iterator<T> iterator() {
+        return this.list.iterator();
+    }
+
+    @Override
+    public Object[] toArray() {
+        return this.list.toArray();
+    }
+
+    @Override
+    public <T1> T1[] toArray(T1[] a) {
+        return this.list.toArray(a);
+    }
+
+    @Override
+    public boolean add(T t) {
+        this.set.add(t);
+
+        return this.list.add(t);
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        this.set.remove(o);
+
+        return this.list.remove(o);
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> c) {
+        return this.set.containsAll(c);
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends T> c) {
+        this.set.addAll(c);
+
+        return this.list.addAll(c);
+    }
+
+    @Override
+    public boolean addAll(int index, Collection<? extends T> c) {
+        this.set.addAll(c);
+
+        return this.list.addAll(index, c);
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> c) {
+        this.set.removeAll(c);
+
+        return this.list.removeAll(c);
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+        this.set.retainAll(c);
+
+        return this.list.retainAll(c);
+    }
+
+    @Override
+    public void clear() {
+        this.set.clear();
+        this.list.clear();
+    }
+
+    @Override
+    public T get(int index) {
+        return this.list.get(index);
+    }
+
+    @Override
+    public T set(int index, T element) {
+        T prev = this.list.set(index, element);
+
+        if (prev != null) {
+            this.set.remove(prev);
+        }
+
+        this.set.add(element);
+
+        return prev;
+    }
+
+    @Override
+    public void add(int index, T element) {
+        this.set.add(element);
+
+        this.list.add(index, element);
+    }
+
+    @Override
+    public T remove(int index) {
+        T prev = this.list.remove(index);
+
+        if (prev != null) {
+            this.set.remove(prev);
+        }
+
+        return prev;
+    }
+
+    @Override
+    public int indexOf(Object o) {
+        return this.list.indexOf(o);
+    }
+
+    @Override
+    public int lastIndexOf(Object o) {
+        return this.list.lastIndexOf(o);
+    }
+
+    @Override
+    public ListIterator<T> listIterator() {
+        return this.list.listIterator();
+    }
+
+    @Override
+    public ListIterator<T> listIterator(int index) {
+        return this.list.listIterator(index);
+    }
+
+    @Override
+    public List<T> subList(int fromIndex, int toIndex) {
+        return this.list.subList(fromIndex, toIndex);
+    }
+
+    public static <T> HashedList<T> wrapper(List<T> list) {
+        return new HashedList<>(list, new HashSet<>(list)); // Yatopia - use hashset
+    }
+}
diff --git a/src/main/java/net/minecraft/server/BiomeSettingsMobs.java b/src/main/java/net/minecraft/server/BiomeSettingsMobs.java
index a18ca3f0001a771f21012bd39711f581efb2fef0..0f88b7b38b6191c3adbebdee82427275640c4197 100644
--- a/src/main/java/net/minecraft/server/BiomeSettingsMobs.java
+++ b/src/main/java/net/minecraft/server/BiomeSettingsMobs.java
@@ -113,7 +113,7 @@ public class BiomeSettingsMobs {
         private final Map<EnumCreatureType, List<BiomeSettingsMobs.c>> a = (Map) Stream.of(EnumCreatureType.values()).collect(Maps.toImmutableEnumMap((enumcreaturetype) -> {
             return enumcreaturetype;
         }, (enumcreaturetype) -> {
-            return new MobList(); // Use MobList instead of ArrayList
+            return me.jellysquid.mods.lithium.common.util.collections.HashedList.wrapper(new MobList()); // Use MobList instead of ArrayList // Yatopia - hashedlist
         }));
         // Paper end
         private final Map<EntityTypes<?>, BiomeSettingsMobs.b> b = Maps.newLinkedHashMap();