From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <40902469+Samsuik@users.noreply.github.com>
Date: Tue, 23 May 2023 23:07:20 +0100
Subject: [PATCH] Sakura Utils


diff --git a/src/main/java/me/samsuik/sakura/utils/collections/EntityTable.java b/src/main/java/me/samsuik/sakura/utils/collections/EntityTable.java
new file mode 100644
index 0000000000000000000000000000000000000000..54292c693f89ee1444f8b22f4c1488e95ef6bcde
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/utils/collections/EntityTable.java
@@ -0,0 +1,25 @@
+package me.samsuik.sakura.utils.collections;
+
+import it.unimi.dsi.fastutil.HashCommon;
+import net.minecraft.world.entity.Entity;
+
+public final class EntityTable {
+
+    private final Entity[] entities;
+    private final int mask;
+
+    public EntityTable(int size) {
+        int n = HashCommon.nextPowerOfTwo(size - 1);
+        entities = new Entity[n];
+        mask = n - 1;
+    }
+
+    public Entity locate(Entity entity) {
+        int pos = entity.blockPosition().hashCode();
+        int key = pos & mask;
+        Entity found = entities[key];
+        entities[key] = entity;
+        return found;
+    }
+
+}
diff --git a/src/main/java/me/samsuik/sakura/utils/collections/OrderedComparatorList.java b/src/main/java/me/samsuik/sakura/utils/collections/OrderedComparatorList.java
new file mode 100644
index 0000000000000000000000000000000000000000..239fc8823b32ae5c8f6e3bfd6ecdde0ccd1e5a8b
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/utils/collections/OrderedComparatorList.java
@@ -0,0 +1,51 @@
+package me.samsuik.sakura.utils.collections;
+
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+public final class OrderedComparatorList<T> extends ObjectArrayList<T> {
+
+    private final Comparator<T> comparator;
+    private boolean binarySearch = true;
+
+    public OrderedComparatorList(int capacity, Comparator<T> comparator) {
+        super(capacity);
+        this.comparator = Comparator.nullsLast(comparator);
+    }
+
+    public OrderedComparatorList(Comparator<T> comparator) {
+        this(DEFAULT_INITIAL_CAPACITY, comparator);
+    }
+
+    private void validateBounds(int index, T t, boolean up) {
+        if (index != 0 && comparator.compare(get(index - 1), t) > 0) {
+            binarySearch = false;
+        } else if (up && index < size() - 1 && comparator.compare(get(index + 1), t) < 0) {
+            binarySearch = false;
+        }
+    }
+
+    @Override
+    public boolean add(T t) {
+        validateBounds(size(), t, false);
+        return super.add(t);
+    }
+
+    @Override
+    public void add(int index, T t) {
+        validateBounds(index, t, true);
+        super.add(index, t);
+    }
+
+    @Override
+    public int indexOf(final Object k) {
+        if (binarySearch) {
+            return Math.max(Arrays.binarySearch(a, (T) k, comparator), -1);
+        } else {
+            return super.indexOf(k);
+        }
+    }
+
+}
diff --git a/src/main/java/me/samsuik/sakura/utils/collections/TrackedEntityChunkMap.java b/src/main/java/me/samsuik/sakura/utils/collections/TrackedEntityChunkMap.java
new file mode 100644
index 0000000000000000000000000000000000000000..267db86c5d12a804d2f9c868df996a3391910cbd
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/utils/collections/TrackedEntityChunkMap.java
@@ -0,0 +1,34 @@
+package me.samsuik.sakura.utils.collections;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+import it.unimi.dsi.fastutil.objects.ObjectCollection;
+import net.minecraft.server.level.ChunkMap;
+
+public final class TrackedEntityChunkMap extends Int2ObjectOpenHashMap<ChunkMap.TrackedEntity> {
+
+    private final ObjectArrayList<ChunkMap.TrackedEntity> entityList = new UnorderedIndexedList<>();
+
+    @Override
+    public ChunkMap.TrackedEntity put(int k, ChunkMap.TrackedEntity trackedEntity) {
+        ChunkMap.TrackedEntity tracked = super.put(k, trackedEntity);
+        // bad plugins may replace entries
+        if (tracked != null)
+            entityList.remove(trackedEntity);
+        entityList.add(trackedEntity);
+        return tracked;
+    }
+
+    @Override
+    public ChunkMap.TrackedEntity remove(int k) {
+        ChunkMap.TrackedEntity tracked = super.remove(k);
+        entityList.remove(tracked);
+        return tracked;
+    }
+
+    @Override
+    public ObjectCollection<ChunkMap.TrackedEntity> values() {
+        return entityList;
+    }
+
+}
diff --git a/src/main/java/me/samsuik/sakura/utils/collections/UnorderedIndexedList.java b/src/main/java/me/samsuik/sakura/utils/collections/UnorderedIndexedList.java
new file mode 100644
index 0000000000000000000000000000000000000000..4ca3bf6d6c7aec3a1b31e6ef4f863fa5c34888bd
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/utils/collections/UnorderedIndexedList.java
@@ -0,0 +1,65 @@
+package me.samsuik.sakura.utils.collections;
+
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+
+public final class UnorderedIndexedList<T> extends ObjectArrayList<T> {
+
+    private final Int2IntOpenHashMap elementToIndex = new Int2IntOpenHashMap();
+
+    {
+        elementToIndex.defaultReturnValue(-1);
+    }
+
+    public UnorderedIndexedList(int capacity) {
+        super(capacity);
+    }
+
+    public UnorderedIndexedList() {
+        super();
+    }
+
+    @Override
+    public boolean add(final T t) {
+        elementToIndex.put(t.hashCode(), size());
+        return super.add(t);
+    }
+
+    @Override
+    public T remove(final int index) {
+        final int tail = size() - 1;
+        final T at = a[index];
+
+        if (index != tail) {
+            final T tailObj = a[tail];
+            if (tailObj != null)
+                elementToIndex.put(tailObj.hashCode(), index);
+            a[index] = tailObj;
+        }
+
+        if (at != null)
+            elementToIndex.remove(at.hashCode());
+        a[tail] = null;
+        size = tail;
+        return at;
+    }
+
+    @Override
+    public void clear() {
+        elementToIndex.clear();
+        super.clear();
+    }
+
+    @Override
+    public int indexOf(final Object k) {
+        if (k == null) return -1;
+        // entities uses their id as a hashcode
+        return elementToIndex.get(k.hashCode());
+    }
+
+    @Override
+    public void add(final int index, final T t) {
+        throw new UnsupportedOperationException();
+    }
+
+}
diff --git a/src/main/java/me/samsuik/sakura/utils/objects/Expiry.java b/src/main/java/me/samsuik/sakura/utils/objects/Expiry.java
new file mode 100644
index 0000000000000000000000000000000000000000..93a5655d9dc355d0596c86ea7b592d14ff941476
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/utils/objects/Expiry.java
@@ -0,0 +1,21 @@
+package me.samsuik.sakura.utils.objects;
+
+public final class Expiry {
+
+    private long expireAt;
+    private final int inc;
+
+    public Expiry(long tick, int inc) {
+        this.expireAt = tick + inc;
+        this.inc = inc;
+    }
+
+    public void refresh(long tick) {
+        this.expireAt = tick + this.inc;
+    }
+
+    public boolean isExpired(long tick) {
+        return tick >= this.expireAt;
+    }
+
+}