isRecipeInputEqual optimization (#351)

* Optimize GT_Recipe.isRecipeInputEqual

Used HEAVILY to catch duplicate recipes during game startup. Worst-case, it
would result in 5 GT_OreDictUnificator.get calls for each pair of inputs.
Instead, this is closer to 1 + 1/N, and as an added bonus, the modified
unification it now uses doesn't copy its output only for it to be discarded
immediately after comparison.

Apart from inproved startup times, this might make a small difference when
machines switch recipes.

I am making an assumption that
GT_OreDictUnificator.get(true, GT_OreDictUnificator.get(false, stack))
is equivalent to a just GT_OreDictUnificator.get(false, stack), and the
original code only double-unificated because it was easier to code. If this
turns out to be false, there's still some performance gain from factoring
out the tStack unification, but some of the optimization here would be lost.

* Changed method visibility according to PR feedback

2 files changed, 56 insertions, 2 deletions

diff --git a/src/main/java/gregtech/api/util/GT_OreDictUnificator.java b/src/main/java/gregtech/api/util/GT_OreDictUnificator.java
index 9d9b45cecf..188af9cfaa 100644
--- a/src/main/java/gregtech/api/util/GT_OreDictUnificator.java
+++ b/src/main/java/gregtech/api/util/GT_OreDictUnificator.java
@@ -156,6 +156,59 @@ public class GT_OreDictUnificator {
         return GT_Utility.copyAmount(aStack.stackSize, rStack);
     }
 
+    /** Doesn't copy the returned stack or set quantity. Be careful and do not mutate it;
+     * intended only to optimize comparisons */
+    static ItemStack get_nocopy(boolean aUseBlackList, ItemStack aStack) {
+        if (GT_Utility.isStackInvalid(aStack)) return null;
+        ItemData tPrefixMaterial = getAssociation(aStack);
+        ItemStack rStack = null;
+        if (tPrefixMaterial == null || !tPrefixMaterial.hasValidPrefixMaterialData() || (aUseBlackList && tPrefixMaterial.mBlackListed))
+            return aStack;
+        if (aUseBlackList && !GregTech_API.sUnificationEntriesRegistered && isBlacklisted(aStack)) {
+            tPrefixMaterial.mBlackListed = true;
+            return aStack;
+        }
+        if (tPrefixMaterial.mUnificationTarget == null)
+            tPrefixMaterial.mUnificationTarget = sName2StackMap.get(tPrefixMaterial.toString());
+        rStack = tPrefixMaterial.mUnificationTarget;
+        if (GT_Utility.isStackInvalid(rStack)) return aStack;
+        assert rStack != null;
+        rStack.setTagCompound(aStack.getTagCompound());
+        return rStack;
+    }
+
+    /** Compares the first argument against an already-unificated second argument as if
+     * aUseBlackList was both true and false. */
+    public static boolean isInputStackEqual(ItemStack aStack, ItemStack unified_tStack) {
+        boolean alreadyCompared = false;
+        if (GT_Utility.isStackInvalid(aStack)) return false;
+        ItemData tPrefixMaterial = getAssociation(aStack);
+        ItemStack rStack = null;
+        if (tPrefixMaterial == null || !tPrefixMaterial.hasValidPrefixMaterialData())
+            return GT_Utility.areStacksEqual(aStack, unified_tStack, true);
+        else if(tPrefixMaterial.mBlackListed) {
+            if (GT_Utility.areStacksEqual(aStack, unified_tStack, true))
+                return true;
+            else
+                alreadyCompared = true;
+        }
+        if (!alreadyCompared && !GregTech_API.sUnificationEntriesRegistered && isBlacklisted(aStack)) {
+            tPrefixMaterial.mBlackListed = true;
+            if (GT_Utility.areStacksEqual(aStack, unified_tStack, true))
+                return true;
+            else
+                alreadyCompared = true;
+        }
+        if (tPrefixMaterial.mUnificationTarget == null)
+            tPrefixMaterial.mUnificationTarget = sName2StackMap.get(tPrefixMaterial.toString());
+        rStack = tPrefixMaterial.mUnificationTarget;
+        if (GT_Utility.isStackInvalid(rStack))
+            return !alreadyCompared && GT_Utility.areStacksEqual(aStack, unified_tStack, true);
+        assert rStack != null;
+        rStack.setTagCompound(aStack.getTagCompound());
+        return GT_Utility.areStacksEqual(rStack, unified_tStack, true);
+    }
+
     public static List<ItemStack> getNonUnifiedStacks(Object obj) {
     	synchronized (sUnificationTable) {
     		if (sUnificationTable.isEmpty() && !sItemStack2DataMap.isEmpty()) {
diff --git a/src/main/java/gregtech/api/util/GT_Recipe.java b/src/main/java/gregtech/api/util/GT_Recipe.java
index bf091695c7..537d92b365 100644
--- a/src/main/java/gregtech/api/util/GT_Recipe.java
+++ b/src/main/java/gregtech/api/util/GT_Recipe.java
@@ -389,11 +389,12 @@ public class GT_Recipe implements Comparable<GT_Recipe> {
         if (mInputs.length > 0 && aInputs == null) return false;
 
         for (ItemStack tStack : mInputs) {
-            if (tStack != null) {
+            ItemStack unified_tStack = GT_OreDictUnificator.get_nocopy(true, tStack);
+            if (unified_tStack != null) {
                 amt = tStack.stackSize;
                 boolean temp = true;
                 for (ItemStack aStack : aInputs) {
-                    if ((GT_Utility.areUnificationsEqual(aStack, tStack, true) || GT_Utility.areUnificationsEqual(GT_OreDictUnificator.get(false, aStack), tStack, true))) {
+                    if (GT_OreDictUnificator.isInputStackEqual(aStack, unified_tStack)) {
                         if (GTppRecipeHelper) {//remove once the fix is out
                             if (GT_Utility.areStacksEqual(aStack, Ic2Items.FluidCell.copy(), true) || GT_Utility.areStacksEqual(aStack, ItemList.Tool_DataStick.get(1L), true) || GT_Utility.areStacksEqual(aStack, ItemList.Tool_DataOrb.get(1L), true)) {
                                 if (!GT_Utility.areStacksEqual(aStack, tStack, false))