Remove all usages of GT_ItemStack2 as Set/Map keys by using fastutil (#2465)

* Replace Maps in GT_OreDictUnificator with fastutil implementations with custom hasher

Removes the need to allocate a GT_ItemStack2 every time these Maps are accessed

* Replace local HashMaps with Reference2LongArrayMaps in GT_Recipe and fix if condition

* Remove GT_ItemStack2 usage from OrePrefixes

* Update GTNHLib requirement in @Mod annotation

* Don't modify stack argument when re-trying `setItemStack2DataMap` access with wildcard value

2 files changed, 41 insertions, 0 deletions

diff --git a/src/main/java/gregtech/api/objects/GT_ItemStack.java b/src/main/java/gregtech/api/objects/GT_ItemStack.java
index 210f807c5d..492655740d 100644
--- a/src/main/java/gregtech/api/objects/GT_ItemStack.java
+++ b/src/main/java/gregtech/api/objects/GT_ItemStack.java
@@ -7,6 +7,7 @@ import net.minecraft.item.ItemStack;
 import gregtech.api.enums.GT_Values;
 import gregtech.api.util.GT_Utility;
 import gregtech.api.util.item.ItemHolder;
+import it.unimi.dsi.fastutil.Hash;
 
 /**
  * An optimization of {@link ItemStack} to have a better {@code hashcode} and {@code equals} in order to improve
@@ -14,6 +15,25 @@ import gregtech.api.util.item.ItemHolder;
  */
 public class GT_ItemStack extends ItemHolder {
 
+    /**
+     * A better {@link Hash.Strategy} for {@link ItemStack}. Implementation originally from {@code GT_ItemStack2}.
+     */
+    public static final Hash.Strategy<ItemStack> ITEMSTACK_HASH_STRATEGY2 = new Hash.Strategy<>() {
+
+        @Override
+        public int hashCode(ItemStack o) {
+            return o.getItem()
+                .hashCode() * 38197 + Items.feather.getDamage(o);
+        }
+
+        @Override
+        public boolean equals(ItemStack a, ItemStack b) {
+            if (a == b) return true;
+            if (a == null || b == null) return false;
+            return a.getItem() == b.getItem() && Items.feather.getDamage(a) == Items.feather.getDamage(b);
+        }
+    };
+
     public final Item mItem;
     public final byte mStackSize;
     public final short mMetaData;
@@ -66,4 +86,22 @@ public class GT_ItemStack extends ItemHolder {
     public int hashCode() {
         return GT_Utility.stackToInt(toStack());
     }
+
+    /**
+     * @see #internalCopyStack(ItemStack, boolean)
+     */
+    public static ItemStack internalCopyStack(ItemStack aStack) {
+        return internalCopyStack(aStack, false);
+    }
+
+    /**
+     * Replicates the copy behavior of {@link #toStack()} but for normal {@link ItemStack}s.
+     *
+     * @param aStack   the stack to copy
+     * @param wildcard whether to use wildcard damage value
+     * @return a copy of the stack with stack size 1 and no NBT
+     */
+    public static ItemStack internalCopyStack(ItemStack aStack, boolean wildcard) {
+        return new ItemStack(aStack.getItem(), 1, wildcard ? GT_Values.W : Items.feather.getDamage(aStack));
+    }
 }
diff --git a/src/main/java/gregtech/api/objects/GT_ItemStack2.java b/src/main/java/gregtech/api/objects/GT_ItemStack2.java
index b137e78829..aa93876830 100644
--- a/src/main/java/gregtech/api/objects/GT_ItemStack2.java
+++ b/src/main/java/gregtech/api/objects/GT_ItemStack2.java
@@ -7,7 +7,10 @@ import net.minecraft.item.ItemStack;
  * GT_ItemStack, but with a better hashCode(). Due to this change, it should not be placed in the same hash based data
  * structure with GT_ItemStack. It also shouldn't be used to construct search query into a hash based data structure
  * that contains GT_ItemStack.
+ *
+ * @deprecated See {@link GT_ItemStack#ITEMSTACK_HASH_STRATEGY2}
  */
+@Deprecated
 public class GT_ItemStack2 extends GT_ItemStack {
 
     public GT_ItemStack2(Item aItem, long aStackSize, long aMetaData) {