PaperMC/Spigot-Server-Patches/0269-Optimize-Hoppers.patch

From 7cd85ceb045d6fc847caa3af14fde0c9ac06e7cf Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 27 Apr 2016 22:09:52 -0400
Subject: [PATCH] Optimize Hoppers

* Removes unnecessary extra calls to .update() that are very expensive
* Lots of itemstack cloning removed. Only clone if the item is actually moved
* Return true when a plugin cancels inventory move item event instead of false, as false causes pulls to cycle through all items.
  However, pushes do not exhibit the same behavior, so this is not something plugins could of been relying on.
* Add option (Default on) to cooldown hoppers when they fail to move an item due to full inventory
* Skip subsequent InventoryMoveItemEvents if a plugin does not use the item after first event fire for an iteration

diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 9fd76dcc90..363e03b65d 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -489,4 +489,12 @@ public class PaperWorldConfig {
         squidMaxSpawnHeight = getDouble("squid-spawn-height.maximum", 0.0D);
     }
 
+    public boolean cooldownHopperWhenFull = true;
+    public boolean disableHopperMoveEvents = false;
+    private void hopperOptimizations() {
+        cooldownHopperWhenFull = getBoolean("hopper.cooldown-when-full", cooldownHopperWhenFull);
+        log("Cooldown Hoppers when Full: " + (cooldownHopperWhenFull ? "enabled" : "disabled"));
+        disableHopperMoveEvents = getBoolean("hopper.disable-move-event", disableHopperMoveEvents);
+        log("Hopper Move Item Events: " + (disableHopperMoveEvents ? "disabled" : "enabled"));
+    }
 }
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index fcf6bac08f..3092913f5b 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -876,6 +876,7 @@ public abstract class MinecraftServer implements ICommandListener, Runnable, IAs
 
             // if (i == 0 || this.getAllowNether()) {
                 WorldServer worldserver = this.worlds.get(i);
+                TileEntityHopper.skipHopperEvents = worldserver.paperConfig.disableHopperMoveEvents || org.bukkit.event.inventory.InventoryMoveItemEvent.getHandlerList().getRegisteredListeners().length == 0;
 
                 this.methodProfiler.a(() -> {
                     return worldserver.getWorldData().getName();
diff --git a/src/main/java/net/minecraft/server/TileEntity.java b/src/main/java/net/minecraft/server/TileEntity.java
index 30d3e19de8..54bfbfc6bc 100644
--- a/src/main/java/net/minecraft/server/TileEntity.java
+++ b/src/main/java/net/minecraft/server/TileEntity.java
@@ -60,6 +60,7 @@ public abstract class TileEntity implements KeyedObject {
         return (MinecraftKey) TileEntity.f.b(oclass);
     }
 
+    static boolean IGNORE_TILE_UPDATES = false; // Paper
     public World getWorld() {
         return this.world;
     }
@@ -138,6 +139,7 @@ public abstract class TileEntity implements KeyedObject {
 
     public void update() {
         if (this.world != null) {
+            if (IGNORE_TILE_UPDATES) return; // Paper
             IBlockData iblockdata = this.world.getType(this.position);
 
             this.g = iblockdata.getBlock().toLegacyData(iblockdata);
diff --git a/src/main/java/net/minecraft/server/TileEntityHopper.java b/src/main/java/net/minecraft/server/TileEntityHopper.java
index e9315f2d5c..5198a590a7 100644
--- a/src/main/java/net/minecraft/server/TileEntityHopper.java
+++ b/src/main/java/net/minecraft/server/TileEntityHopper.java
@@ -196,6 +196,154 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
         return false;
     }
 
+    // Paper start - Optimize Hoppers
+    private static boolean skipPullModeEventFire = false;
+    private static boolean skipPushModeEventFire = false;
+    static boolean skipHopperEvents = false;
+
+    private boolean hopperPush(IInventory iinventory, EnumDirection enumdirection) {
+        skipPushModeEventFire = skipHopperEvents;
+        boolean foundItem = false;
+        for (int i = 0; i < this.getSize(); ++i) {
+            if (!this.getItem(i).isEmpty()) {
+                foundItem = true;
+                ItemStack origItemStack = this.getItem(i);
+                ItemStack itemstack = origItemStack;
+
+                final int origCount = origItemStack.getCount();
+                final int moved = Math.min(world.spigotConfig.hopperAmount, origCount);
+                origItemStack.setCount(moved);
+
+                // We only need to fire the event once to give protection plugins a chance to cancel this event
+                // Because nothing uses getItem, every event call should end up the same result.
+                if (!skipPushModeEventFire) {
+                    itemstack = callPushMoveEvent(iinventory, itemstack);
+                    if (itemstack == null) { // cancelled
+                        origItemStack.setCount(origCount);
+                        return false;
+                    }
+                }
+                final ItemStack itemstack2 = addItem(this, iinventory, itemstack, enumdirection);
+                final int remaining = itemstack2.getCount();
+                if (remaining != moved) {
+                    origItemStack = origItemStack.cloneItemStack();
+                    origItemStack.setCount(origCount - moved + remaining);
+                    this.setItem(i, origItemStack);
+                    iinventory.update();
+                    return true;
+                }
+                origItemStack.setCount(origCount);
+            }
+        }
+        if (foundItem && world.paperConfig.cooldownHopperWhenFull) { // Inventory was full - cooldown
+            this.setCooldown(world.spigotConfig.hopperTransfer);
+        }
+        return false;
+    }
+
+    private static boolean hopperPull(IHopper ihopper, IInventory iinventory, int i) {
+        ItemStack origItemStack = iinventory.getItem(i);
+        ItemStack itemstack = origItemStack;
+        final int origCount = origItemStack.getCount();
+        final World world = ihopper.getWorld();
+        final int moved = Math.min(world.spigotConfig.hopperAmount, origCount);
+        itemstack.setCount(moved);
+
+        if (!skipPullModeEventFire) {
+            itemstack = callPullMoveEvent(ihopper, iinventory, itemstack);
+            if (itemstack == null) { // cancelled
+                origItemStack.setCount(origCount);
+                // Drastically improve performance by returning true.
+                // No plugin could of relied on the behavior of false as the other call
+                // site for IMIE did not exhibit the same behavior
+                return true;
+            }
+        }
+
+        final ItemStack itemstack2 = addItem(iinventory, ihopper, itemstack, null);
+        final int remaining = itemstack2.getCount();
+        if (remaining != moved) {
+            origItemStack = origItemStack.cloneItemStack();
+            origItemStack.setCount(origCount - moved + remaining);
+            IGNORE_TILE_UPDATES = true;
+            iinventory.setItem(i, origItemStack);
+            IGNORE_TILE_UPDATES = false;
+            iinventory.update();
+            return true;
+        }
+        origItemStack.setCount(origCount);
+
+        if (world.paperConfig.cooldownHopperWhenFull) {
+            cooldownHopper(ihopper);
+        }
+
+        return false;
+    }
+
+    private ItemStack callPushMoveEvent(IInventory iinventory, ItemStack itemstack) {
+        Inventory destinationInventory = getInventory(iinventory);
+        InventoryMoveItemEvent event = new InventoryMoveItemEvent(this.getOwner(false).getInventory(),
+                CraftItemStack.asCraftMirror(itemstack), destinationInventory, true);
+        boolean result = event.callEvent();
+        if (!event.calledGetItem && !event.calledSetItem) {
+            skipPushModeEventFire = true;
+        }
+        if (!result) {
+            cooldownHopper(this);
+            return null;
+        }
+
+        if (event.calledSetItem) {
+            return CraftItemStack.asNMSCopy(event.getItem());
+        } else {
+            return itemstack;
+        }
+    }
+
+    private static ItemStack callPullMoveEvent(IHopper hopper, IInventory iinventory, ItemStack itemstack) {
+        Inventory sourceInventory = getInventory(iinventory);
+        Inventory destination = getInventory(hopper);
+
+        InventoryMoveItemEvent event = new InventoryMoveItemEvent(sourceInventory,
+                // Mirror is safe as we no plugins ever use this item
+                CraftItemStack.asCraftMirror(itemstack), destination, false);
+        boolean result = event.callEvent();
+        if (!event.calledGetItem && !event.calledSetItem) {
+            skipPullModeEventFire = true;
+        }
+        if (!result) {
+            cooldownHopper(hopper);
+            return null;
+        }
+
+        if (event.calledSetItem) {
+            return CraftItemStack.asNMSCopy(event.getItem());
+        } else {
+            return itemstack;
+        }
+    }
+
+    private static Inventory getInventory(IInventory iinventory) {
+        Inventory sourceInventory;// Have to special case large chests as they work oddly
+        if (iinventory instanceof InventoryLargeChest) {
+            sourceInventory = new org.bukkit.craftbukkit.inventory.CraftInventoryDoubleChest((InventoryLargeChest) iinventory);
+        } else if (iinventory instanceof TileEntity) {
+            sourceInventory = ((TileEntity) iinventory).getOwner(false).getInventory();
+        } else {
+            sourceInventory = iinventory.getOwner().getInventory();
+        }
+        return sourceInventory;
+    }
+
+    private static void cooldownHopper(IHopper hopper) {
+        if (hopper instanceof TileEntityHopper) {
+            ((TileEntityHopper) hopper).setCooldown(hopper.getWorld().spigotConfig.hopperTransfer);
+        } else if (hopper instanceof EntityMinecartHopper) {
+            ((EntityMinecartHopper) hopper).setCooldown(hopper.getWorld().spigotConfig.hopperTransfer / 2);
+        }
+    }
+
+    // Paper end
     private boolean s() {
         IInventory iinventory = this.I();
 
@@ -207,6 +355,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
             if (this.a(iinventory, enumdirection)) {
                 return false;
             } else {
+                return hopperPush(iinventory, enumdirection); /* // Paper - disable rest
                 for (int i = 0; i < this.getSize(); ++i) {
                     if (!this.getItem(i).isEmpty()) {
                         ItemStack itemstack = this.getItem(i).cloneItemStack();
@@ -248,7 +397,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
                     }
                 }
 
-                return false;
+                return false;*/ // Paper - end commenting out replaced block for Hopper Optimizations
             }
         }
     }
@@ -326,6 +475,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
             if (b(iinventory, enumdirection)) {
                 return false;
             }
+            skipPullModeEventFire = skipHopperEvents; // Paper
 
             if (iinventory instanceof IWorldInventory) {
                 IWorldInventory iworldinventory = (IWorldInventory) iinventory;
@@ -368,6 +518,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
         ItemStack itemstack = iinventory.getItem(i);
 
         if (!itemstack.isEmpty() && b(iinventory, itemstack, i, enumdirection)) {
+            return hopperPull(ihopper, iinventory, i); /* // Paper - disable rest
             ItemStack itemstack1 = itemstack.cloneItemStack();
             // ItemStack itemstack2 = addItem(iinventory, ihopper, iinventory.splitStack(i, 1), (EnumDirection) null);
             // CraftBukkit start - Call event on collection of items from inventories into the hopper
@@ -408,7 +559,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
             }
 
             itemstack1.subtract(origCount - itemstack2.getCount()); // Spigot
-            iinventory.setItem(i, itemstack1);
+            iinventory.setItem(i, itemstack1);*/ // Paper - end commenting out replaced block for Hopper Optimizations
         }
 
         return false;
@@ -422,7 +573,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
             return false;
         } else {
             // CraftBukkit start
-            InventoryPickupItemEvent event = new InventoryPickupItemEvent(iinventory1.getOwner().getInventory(), (org.bukkit.entity.Item) entityitem.getBukkitEntity());
+            InventoryPickupItemEvent event = new InventoryPickupItemEvent(getInventory(iinventory1), (org.bukkit.entity.Item) entityitem.getBukkitEntity()); // Paper - avoid snapshot creation
             entityitem.world.getServer().getPluginManager().callEvent(event);
             if (event.isCancelled()) {
                 return false;
@@ -477,7 +628,9 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
             boolean flag1 = iinventory1.x_();
 
             if (itemstack1.isEmpty()) {
+                IGNORE_TILE_UPDATES = true; // Paper
                 iinventory1.setItem(i, itemstack);
+                IGNORE_TILE_UPDATES = false; // Paper
                 itemstack = ItemStack.a;
                 flag = true;
             } else if (a(itemstack1, itemstack)) {
-- 
2.18.0