PaperMC/patches/unapplied/server/1034-Improve-performance-of-mass-crafts.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Sun, 13 Aug 2023 15:41:52 -0700
Subject: [PATCH] Improve performance of mass crafts

When the server crafts all available items in CraftingMenu or InventoryMenu the game
checks either 4 or 9 times for each individual craft for a matching recipe for that container.
This check can be expensive if 64 total crafts are being performed with the recipe matching logic
being run 64 * 9 + 64 times. A breakdown of those times is below. This patch caches the last matching
recipe so that it is checked first and only if it doesn't match does the rest of the matching logic run.

Shift-click crafts are processed one at a time, so shift clicking on an item in the result of a iron block craft
where all the 9 inputs are full stacks of iron will run 64 iron block crafts. For each of those crafts, the
'remaining' blocks are calculated. This is due to recipes that have leftover items like buckets. This is done
for each craft, and done once to get the full 9 leftover items which are usually air. Then 1 item is removed
from each of the 9 inputs and each time that happens, logic is triggered to update the result itemstack. So
for each craft, that logic is run 9 times (hence the 64 * 9). The + 64 is from the 64 checks for remaining items.

After this patch, the full iteration over all recipes checking for a match should run once for a full craft to find the
initial recipe match. Then that recipe will be checked first for all future recipe match checks.

diff --git a/src/main/java/net/minecraft/world/inventory/CraftingMenu.java b/src/main/java/net/minecraft/world/inventory/CraftingMenu.java
index 7a0c1a55a211035bbca7b97293e94b04ae308bae..c3800bdd5096cb06e085e28f6bf0f65586ecf11e 100644
--- a/src/main/java/net/minecraft/world/inventory/CraftingMenu.java
+++ b/src/main/java/net/minecraft/world/inventory/CraftingMenu.java
@@ -76,7 +76,8 @@ public class CraftingMenu extends RecipeBookMenu<CraftingContainer> {
         if (!world.isClientSide) {
             ServerPlayer entityplayer = (ServerPlayer) player;
             ItemStack itemstack = ItemStack.EMPTY;
-            Optional<RecipeHolder<CraftingRecipe>> optional = world.getServer().getRecipeManager().getRecipeFor(RecipeType.CRAFTING, craftingInventory, world);
+            final RecipeHolder<?> currentRecipe = craftingInventory.getCurrentRecipe(); // Paper - Perf: Improve mass crafting; check last recipe used first
+            Optional<RecipeHolder<CraftingRecipe>> optional = currentRecipe == null ? world.getServer().getRecipeManager().getRecipeFor(RecipeType.CRAFTING, craftingInventory, world) : world.getServer().getRecipeManager().getRecipeFor(RecipeType.CRAFTING, craftingInventory, world, currentRecipe.id()).map(com.mojang.datafixers.util.Pair::getSecond); // Paper - Perf: Improve mass crafting; check last recipe used first
 
             if (optional.isPresent()) {
                 RecipeHolder<CraftingRecipe> recipeholder = (RecipeHolder) optional.get();
diff --git a/src/main/java/net/minecraft/world/inventory/ResultSlot.java b/src/main/java/net/minecraft/world/inventory/ResultSlot.java
index 113460eff5121788fce44d6569ec07deb9701b20..accf752e7615f775483830f81bd0df30e40d3c7f 100644
--- a/src/main/java/net/minecraft/world/inventory/ResultSlot.java
+++ b/src/main/java/net/minecraft/world/inventory/ResultSlot.java
@@ -58,7 +58,7 @@ public class ResultSlot extends Slot {
     @Override
     public void onTake(Player player, ItemStack stack) {
         this.checkTakeAchievements(stack);
-        NonNullList<ItemStack> nonNullList = player.level().getRecipeManager().getRemainingItemsFor(RecipeType.CRAFTING, this.craftSlots, player.level());
+        NonNullList<ItemStack> nonNullList = player.level().getRecipeManager().getRemainingItemsFor(RecipeType.CRAFTING, this.craftSlots, player.level(), this.craftSlots.getCurrentRecipe() != null ? this.craftSlots.getCurrentRecipe().id() : null); // Paper - Perf: Improve mass crafting; check last recipe used first
 
         for (int i = 0; i < nonNullList.size(); i++) {
             ItemStack itemStack = this.craftSlots.getItem(i);
diff --git a/src/main/java/net/minecraft/world/item/crafting/RecipeManager.java b/src/main/java/net/minecraft/world/item/crafting/RecipeManager.java
index a0ab3c55826af292d1cdac05648139b4d31f1376..d87124f5356180a37e581febc6141fdc5f1395a7 100644
--- a/src/main/java/net/minecraft/world/item/crafting/RecipeManager.java
+++ b/src/main/java/net/minecraft/world/item/crafting/RecipeManager.java
@@ -122,13 +122,16 @@ public class RecipeManager extends SimpleJsonResourceReloadListener {
             RecipeHolder<T> recipeholder = (RecipeHolder) map.get(id);
 
             if (recipeholder != null && recipeholder.value().matches(inventory, world)) {
+                inventory.setCurrentRecipe(recipeholder); // Paper - Perf: Improve mass crafting
                 return Optional.of(Pair.of(id, recipeholder));
             }
         }
 
+        inventory.setCurrentRecipe(null); // Paper - Perf: Improve mass crafting;; clear before it might be set again
         return map.entrySet().stream().filter((entry) -> {
             return ((RecipeHolder) entry.getValue()).value().matches(inventory, world);
         }).findFirst().map((entry) -> {
+            inventory.setCurrentRecipe(entry.getValue()); // Paper - Perf: Improve mass crafting
             return Pair.of((ResourceLocation) entry.getKey(), (RecipeHolder) entry.getValue());
         });
     }
@@ -150,7 +153,12 @@ public class RecipeManager extends SimpleJsonResourceReloadListener {
     }
 
     public <C extends Container, T extends Recipe<C>> NonNullList<ItemStack> getRemainingItemsFor(RecipeType<T> type, C inventory, Level world) {
-        Optional<RecipeHolder<T>> optional = this.getRecipeFor(type, inventory, world);
+        // Paper start - Perf: Improve mass crafting;; check last recipe used first
+        return this.getRemainingItemsFor(type, inventory, world, null);
+    }
+    public <C extends Container, T extends Recipe<C>> NonNullList<ItemStack> getRemainingItemsFor(RecipeType<T> type, C inventory, Level world, @Nullable ResourceLocation firstToCheck) {
+        Optional<RecipeHolder<T>> optional = firstToCheck == null ? this.getRecipeFor(type, inventory, world) : this.getRecipeFor(type, inventory, world, firstToCheck).map(Pair::getSecond);
+        // Paper end - Perf: Improve mass crafting
 
         if (optional.isPresent()) {
             return ((RecipeHolder) optional.get()).value().getRemainingItems(inventory);