From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Gegy <gegy1000@gmail.com>
Date: Fri, 21 Jan 2022 10:19:06 -0500
Subject: [PATCH] lithium: shapes.blockstate_cache

Original code by CaffeineMC, licensed under GNU Lesser General Public License v3.0
You can find the original code on https://github.com/CaffeineMC/lithium-fabric (Yarn mappings)

diff --git a/src/main/java/me/jellysquid/mods/lithium/common/util/collections/Object2BooleanCacheTable.java b/src/main/java/me/jellysquid/mods/lithium/common/util/collections/Object2BooleanCacheTable.java
new file mode 100644
index 0000000000000000000000000000000000000000..a833ec84b2053c805dd33821cc08939c1cb79e96
--- /dev/null
+++ b/src/main/java/me/jellysquid/mods/lithium/common/util/collections/Object2BooleanCacheTable.java
@@ -0,0 +1,59 @@
+package me.jellysquid.mods.lithium.common.util.collections;
+
+import it.unimi.dsi.fastutil.HashCommon;
+import java.util.function.Predicate;
+import net.minecraft.util.Mth;
+
+/**
+ * A lossy hashtable implementation that stores a mapping between an object and a boolean.
+ * <p>
+ * Any hash collisions will result in an overwrite: this is safe because the correct value can always be recomputed,
+ * given that the given operator is deterministic.
+ * <p>
+ * This implementation is safe to use from multiple threads
+ */
+public final class Object2BooleanCacheTable<T> {
+    private final int mask;
+
+    private final Node<T>[] nodes;
+
+    private final Predicate<T> operator;
+
+    @SuppressWarnings("unchecked")
+    public Object2BooleanCacheTable(int capacity, Predicate<T> operator) {
+        int capacity1 = Mth.smallestEncompassingPowerOfTwo(capacity);
+        this.mask = capacity1 - 1;
+
+        this.nodes = (Node<T>[]) new Node[capacity1];
+
+        this.operator = operator;
+    }
+
+    private static <T> int hash(T key) {
+        return HashCommon.mix(key.hashCode());
+    }
+
+    public boolean get(T key) {
+        int idx = hash(key) & this.mask;
+
+        Node<T> node = this.nodes[idx];
+        if (node != null && key.equals(node.key)) {
+            return node.value;
+        }
+
+        boolean test = this.operator.test(key);
+        this.nodes[idx] = new Node<>(key, test);
+
+        return test;
+    }
+
+    static class Node<T> {
+        final T key;
+        final boolean value;
+
+        Node(T key, boolean value) {
+            this.key = key;
+            this.value = value;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/net/minecraft/world/level/block/Block.java b/src/main/java/net/minecraft/world/level/block/Block.java
index dfe1e522a747b894d43124b97eaceb0ab196ac44..1834470b549d8352317cf081173ff542c9faac1e 100644
--- a/src/main/java/net/minecraft/world/level/block/Block.java
+++ b/src/main/java/net/minecraft/world/level/block/Block.java
@@ -64,17 +64,19 @@ import net.minecraft.world.phys.shapes.BooleanOp;
 import net.minecraft.world.phys.shapes.Shapes;
 import net.minecraft.world.phys.shapes.VoxelShape;
 import org.slf4j.Logger;
+import me.jellysquid.mods.lithium.common.util.collections.Object2BooleanCacheTable; // JettPack
 
 public class Block extends BlockBehaviour implements ItemLike {
 
     private static final Logger LOGGER = LogUtils.getLogger();
     private final Holder.Reference<Block> builtInRegistryHolder;
     public static final IdMapper<BlockState> BLOCK_STATE_REGISTRY = new IdMapper<>();
-    private static final LoadingCache<VoxelShape, Boolean> SHAPE_FULL_BLOCK_CACHE = CacheBuilder.newBuilder().maximumSize(512L).weakKeys().build(new CacheLoader<VoxelShape, Boolean>() {
-        public Boolean load(VoxelShape voxelshape) {
-            return !Shapes.joinIsNotEmpty(Shapes.block(), voxelshape, BooleanOp.NOT_SAME);
-        }
-    });
+    // JettPack start - lithium: shapes.blockstate_cache
+    private static final Object2BooleanCacheTable<VoxelShape> FULL_CUBE_CACHE = new Object2BooleanCacheTable<>(
+            512,
+            shape -> !Shapes.joinIsNotEmpty(Shapes.block(), shape, BooleanOp.NOT_SAME)
+    );
+    // JettPack end
     public static final int UPDATE_NEIGHBORS = 1;
     public static final int UPDATE_CLIENTS = 2;
     public static final int UPDATE_INVISIBLE = 4;
@@ -281,7 +283,7 @@ public class Block extends BlockBehaviour implements ItemLike {
     }
 
     public static boolean isShapeFullBlock(VoxelShape shape) {
-        return (Boolean) Block.SHAPE_FULL_BLOCK_CACHE.getUnchecked(shape);
+        return FULL_CUBE_CACHE.get(shape); // JettPack - lithium: shapes.blockstate_cache
     }
 
     public boolean propagatesSkylightDown(BlockState state, BlockGetter world, BlockPos pos) {