spigot/CraftBukkit-Patches/0135-Use-FastMatches-for-ItemStack-Dirty-Check.patch

From 5f5e60e80a1a80a53c0c9ab4be3524d79a0d6a38 Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
Date: Sun, 22 Feb 2015 12:27:40 +1100
Subject: [PATCH] Use FastMatches for ItemStack Dirty Check

The check to find dirty itemstacks and send update packets each tick can be very intensive as it checks the entire itemstack, including the entire NBT map. To save on this, 19/20 times we will simply compare the basic count/data/type. If for some strange reason the NBT of an item already existing in an inventory is changes, it will take up to 1 second to show, with an average time of half a second. This odd 0.5 second delay is far preferable to lag every tick, and shouldn't be noticed by anyone.

diff --git a/src/main/java/net/minecraft/server/Container.java b/src/main/java/net/minecraft/server/Container.java
index a985405a..686250ea 100644
--- a/src/main/java/net/minecraft/server/Container.java
+++ b/src/main/java/net/minecraft/server/Container.java
@@ -28,6 +28,7 @@ public abstract class Container {
     private final Set<Slot> h = Sets.newHashSet();
     protected List<ICrafting> listeners = Lists.newArrayList();
     private final Set<EntityHuman> i = Sets.newHashSet();
+    private int tickCount; // Spigot
 
     // CraftBukkit start
     public boolean checkReachable = true;
@@ -75,7 +76,7 @@ public abstract class Container {
             ItemStack itemstack = ((Slot) this.c.get(i)).getItem();
             ItemStack itemstack1 = (ItemStack) this.b.get(i);
 
-            if (!ItemStack.matches(itemstack1, itemstack)) {
+            if (!ItemStack.fastMatches(itemstack1, itemstack) || (tickCount % org.spigotmc.SpigotConfig.itemDirtyTicks == 0 && !ItemStack.matches(itemstack1, itemstack))) { // Spigot
                 itemstack1 = itemstack.isEmpty() ? ItemStack.a : itemstack.cloneItemStack();
                 this.b.set(i, itemstack1);
 
@@ -84,6 +85,7 @@ public abstract class Container {
                 }
             }
         }
+        tickCount++; // Spigot
 
     }
 
diff --git a/src/main/java/net/minecraft/server/ItemStack.java b/src/main/java/net/minecraft/server/ItemStack.java
index 00ffb05a..aca63be5 100644
--- a/src/main/java/net/minecraft/server/ItemStack.java
+++ b/src/main/java/net/minecraft/server/ItemStack.java
@@ -469,6 +469,18 @@ public final class ItemStack {
         return itemstack.isEmpty() && itemstack1.isEmpty() ? true : (!itemstack.isEmpty() && !itemstack1.isEmpty() ? (itemstack.tag == null && itemstack1.tag != null ? false : itemstack.tag == null || itemstack.tag.equals(itemstack1.tag)) : false);
     }
 
+    // Spigot Start
+    public static boolean fastMatches(ItemStack itemstack, ItemStack itemstack1) {
+        if (itemstack.isEmpty() && itemstack1.isEmpty()) {
+            return true;
+        }
+        if (!itemstack.isEmpty() && !itemstack1.isEmpty()) {
+            return itemstack.count == itemstack1.count && itemstack.item == itemstack1.item && itemstack.damage == itemstack1.damage;
+        }
+        return false;
+    }
+    // Spigot End
+
     public static boolean matches(ItemStack itemstack, ItemStack itemstack1) {
         return itemstack.isEmpty() && itemstack1.isEmpty() ? true : (!itemstack.isEmpty() && !itemstack1.isEmpty() ? itemstack.d(itemstack1) : false);
     }
diff --git a/src/main/java/org/spigotmc/SpigotConfig.java b/src/main/java/org/spigotmc/SpigotConfig.java
index 231b4fa5..d386a876 100644
--- a/src/main/java/org/spigotmc/SpigotConfig.java
+++ b/src/main/java/org/spigotmc/SpigotConfig.java
@@ -388,4 +388,9 @@ public class SpigotConfig
             Bukkit.getLogger().info( "Debug logging is disabled" );
         }
     }
+
+    public static int itemDirtyTicks;
+    private static void itemDirtyTicks() {
+        itemDirtyTicks = getInt("settings.item-dirty-ticks", 20);
+    }
 }
-- 
2.11.0