perf: avoid block snapshots in inventory click and close handlers

src/main/java/net/tfminecraft/thievery/door/ContainerManager.java

@@ -307,13 +307,15 @@ public void onInventoryClick(InventoryClickEvent event) {
         if (!(event.getWhoClicked() instanceof Player player)) return;
 
         Inventory inv = event.getInventory();
-        InventoryHolder holder = inv.getHolder();
+        // Fires on every inventory click, so avoid block-state snapshots here.
+        InventoryHolder holder = inv.getHolder(false);
 
         Location location;
 
         if (holder instanceof DoubleChest doubleChest) {
             // Always use the left side as the primary location
-            location = ((Chest) doubleChest.getLeftSide()).getBlock().getLocation();
+            if (!(doubleChest.getLeftSide(false) instanceof Chest left)) return;
+            location = left.getBlock().getLocation();
         } else if (holder instanceof Container container) {
             location = container.getBlock().getLocation();
         } else {
@@ -324,9 +326,10 @@ public void onInventoryClick(InventoryClickEvent event) {
         if (event.getClick() == ClickType.LEFT || event.getClick() == ClickType.SHIFT_LEFT) {
             if (event.getCurrentItem() == null || event.getCurrentItem().getType().isAir()) return;
 
-            ContainerData data = containerDataManager.loadContainerData(location);
+            // The cached owner skips the disk read for unowned containers.
+            if (containerDataManager.getOwner(location) == null) return;
 
-            if (data.getOwner() == null) return;
+            ContainerData data = containerDataManager.loadContainerData(location);
 
             if (!data.canAccess(player) && !player.hasPermission("thievery.admin")) {
                 long now = System.currentTimeMillis();

src/main/java/net/tfminecraft/thievery/player/InventoryManager.java

@@ -163,7 +163,7 @@ private void applySession(Player player, LoadoutSession session) {
     @EventHandler
     public void onInventoryClick(InventoryClickEvent e) {
         if (!(e.getWhoClicked() instanceof Player player)) return;
-        if (!(e.getView().getTopInventory().getHolder() instanceof LoadoutHolder holder)) return;
+        if (!(e.getView().getTopInventory().getHolder(false) instanceof LoadoutHolder holder)) return;
         if (!holder.getPlayerId().equals(player.getUniqueId())) return;
 
         e.setCancelled(true);
@@ -235,7 +235,7 @@ public void onInventoryClick(InventoryClickEvent e) {
     @EventHandler
     public void onInventoryClose(InventoryCloseEvent e) {
         if (!(e.getPlayer() instanceof Player player)) return;
-        if (!(e.getView().getTopInventory().getHolder() instanceof LoadoutHolder holder)) return;
+        if (!(e.getView().getTopInventory().getHolder(false) instanceof LoadoutHolder holder)) return;
         if (!holder.getPlayerId().equals(player.getUniqueId())) return;
 
         sessions.remove(player.getUniqueId());

src/main/java/net/tfminecraft/thievery/steal/StealGui.java

@@ -438,7 +438,7 @@ public static void updateTitle(Player player, StealGuiHolder holder, String titl
         if (player == null || !player.isOnline() || holder == null || title == null) {
             return;
         }
-        if (!(player.getOpenInventory().getTopInventory().getHolder() instanceof StealGuiHolder openHolder)) {
+        if (!(player.getOpenInventory().getTopInventory().getHolder(false) instanceof StealGuiHolder openHolder)) {
             return;
         }
         if (!openHolder.getPlayerId().equals(holder.getPlayerId()) || openHolder.getKind() != holder.getKind()) {

src/main/java/net/tfminecraft/thievery/steal/StealManager.java

@@ -112,7 +112,9 @@ public static StealGuiHolder getStealGuiHolder(Inventory inventory) {
         if (inventory == null) {
             return null;
         }
-        InventoryHolder inventoryHolder = inventory.getHolder();
+        // Runs on every inventory click and close, and every tick per session. getHolder() would copy a block
+        // inventory (a barrel reloads all of its items) just to answer this.
+        InventoryHolder inventoryHolder = inventory.getHolder(false);
         return inventoryHolder instanceof StealGuiHolder stealGuiHolder ? stealGuiHolder : null;
     }
 

src/test/java/net/tfminecraft/thievery/TestInventories.java

@@ -0,0 +1,21 @@
+package net.tfminecraft.thievery;
+
+import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.spy;
+
+import org.bukkit.inventory.Inventory;
+
+/** MockBukkit leaves Paper's non-snapshot getHolder(boolean) unimplemented; the plugin uses it on hot paths. */
+public final class TestInventories {
+
+    private TestInventories() {
+    }
+
+    /** A spy of {@code inventory} whose getHolder(boolean) answers with the wrapped inventory's holder. */
+    public static Inventory withHolderLookup(Inventory inventory) {
+        Inventory spied = spy(inventory);
+        doAnswer(call -> inventory.getHolder()).when(spied).getHolder(anyBoolean());
+        return spied;
+    }
+}

src/test/java/net/tfminecraft/thievery/door/ContainerManagerTest.java

@@ -5,6 +5,7 @@
 import java.util.*;
 import net.tfminecraft.rpcharacters.grave.GraveManager;
 import net.tfminecraft.thievery.utils.ToolResolver;
+import net.tfminecraft.thievery.TestInventories;
 import org.bukkit.*;
 import org.bukkit.block.*;
 import org.bukkit.entity.*;
@@ -114,7 +115,7 @@ record DoubleFixture(Block block, Chest left, Chest right, DoubleChest holder, D
     }
 
     @Test void clickingPluginMenuDoesNotInspectLocksOrAlertStaff() {
-        var inventory=Bukkit.createInventory(null,9,"Menu");
+        var inventory=TestInventories.withHolderLookup(Bukkit.createInventory(null,9,"Menu"));
         var event=mock(InventoryClickEvent.class);
         when(event.getWhoClicked()).thenReturn(player);
         when(event.getInventory()).thenReturn(inventory);
@@ -128,6 +129,36 @@ record DoubleFixture(Block block, Chest left, Chest right, DoubleChest holder, D
         verify(event,never()).setCancelled(true);
     }
 
+    @Test void takingFromUnownedContainerSkipsTheDataFileAndBlockSnapshot() {
+        var barrel=block(0,Material.BARREL); var inventory=TestInventories.withHolderLookup(((Container)barrel.getState()).getInventory());
+        var event=mock(InventoryClickEvent.class);
+        when(event.getWhoClicked()).thenReturn(player);
+        when(event.getInventory()).thenReturn(inventory);
+        when(event.getClick()).thenReturn(ClickType.LEFT);
+        when(event.getCurrentItem()).thenReturn(new ItemStack(Material.DIAMOND));
+
+        manager.onInventoryClick(event);
+
+        verify(storage).getOwner(barrel.getLocation());
+        verify(storage,never()).loadContainerData(any());
+        verify(inventory,never()).getHolder();
+    }
+
+    @Test void clickingDoubleChestWhoseLeftHalfIsNoLongerAChestIsIgnored() {
+        var inventory=mock(DoubleChestInventory.class); var leftless=mock(Inventory.class);
+        when(leftless.getHolder(false)).thenReturn(mock(org.bukkit.inventory.InventoryHolder.class));
+        when(inventory.getLeftSide()).thenReturn(leftless); when(inventory.getHolder(false)).thenReturn(new DoubleChest(inventory));
+        var event=mock(InventoryClickEvent.class);
+        when(event.getWhoClicked()).thenReturn(player);
+        when(event.getInventory()).thenReturn(inventory);
+        when(event.getClick()).thenReturn(ClickType.LEFT);
+        when(event.getCurrentItem()).thenReturn(new ItemStack(Material.DIAMOND));
+
+        assertDoesNotThrow(()->manager.onInventoryClick(event));
+
+        verifyNoInteractions(storage);
+    }
+
     @Test void accessToLeftHalfDoesNotAllowOpeningForeignRightHalfButStaffCanBypassSilently() {
         var chest=doubleChest();
         var left=lock(chest.block(),player.getUniqueId());
@@ -278,7 +309,7 @@ DoubleFixture doubleChest() {
         data.put(chest.left().getLocation(),new ContainerData(chest.left().getLocation(),UUID.randomUUID())); manager.onInventoryMoveItem(event); verify(event).setCancelled(true);
     }
     @Test void takingFromForeignContainerAlertsOnlyOptedInStaffAndThrottlesRepeats() {
-        var barrel=block(0,Material.BARREL); var inventory=((Container)barrel.getState()).getInventory(); var lock=lock(barrel,UUID.randomUUID());
+        var barrel=block(0,Material.BARREL); var inventory=TestInventories.withHolderLookup(((Container)barrel.getState()).getInventory()); var lock=lock(barrel,UUID.randomUUID());
         var staff=mock(Player.class); when(staff.getUniqueId()).thenReturn(UUID.randomUUID()); when(staff.hasPermission("thievery.admin")).thenReturn(true);
         var disabled=mock(Player.class); when(disabled.getUniqueId()).thenReturn(UUID.randomUUID()); when(disabled.hasPermission("thievery.admin")).thenReturn(true); var ordinary=mock(Player.class);
         manager.enableFeedback(staff);

src/test/java/net/tfminecraft/thievery/player/InventoryManagerTest.java

@@ -4,6 +4,7 @@
 import static org.mockito.Mockito.*;
 import java.util.*;
 import net.tfminecraft.thievery.Thievery;
+import net.tfminecraft.thievery.TestInventories;
 import net.tfminecraft.thievery.cache.Cache;
 import net.tfminecraft.thievery.category.ItemCategory;
 import net.tfminecraft.thievery.loader.CategoryLoader;
@@ -24,7 +25,7 @@ class InventoryManagerTest {
         MockBukkit.mock(); points=Cache.categoryPoints; Cache.categoryPoints=30; categories=new ArrayList<>(); byId=new HashMap<>();
         plugins=mockStatic(Thievery.class,RETURNS_DEEP_STUBS); var plugin=mock(Thievery.class); when(plugin.namespace()).thenReturn("thievery"); plugins.when(Thievery::getInstance).thenReturn(plugin);
         player=mock(Player.class); when(player.getUniqueId()).thenReturn(UUID.randomUUID()); data=new PlayerData(player.getUniqueId()); when(Thievery.getPlayerManager().get(player)).thenReturn(data);
-        view=mock(InventoryView.class); when(player.getOpenInventory()).thenReturn(view); doAnswer(call->{inventory=call.getArgument(0); when(view.getTopInventory()).thenReturn(inventory); return view;}).when(player).openInventory(any(Inventory.class));
+        view=mock(InventoryView.class); when(player.getOpenInventory()).thenReturn(view); doAnswer(call->{inventory=TestInventories.withHolderLookup(call.getArgument(0)); when(view.getTopInventory()).thenReturn(inventory); return view;}).when(player).openInventory(any(Inventory.class));
         loader=mockStatic(CategoryLoader.class); loader.when(CategoryLoader::getLoadoutCategories).thenReturn(categories); loader.when(()->CategoryLoader.getById(anyString())).thenAnswer(call->byId.get(call.getArgument(0))); manager=new InventoryManager();
     }
     @AfterEach void close() { loader.close(); plugins.close(); Cache.categoryPoints=points; MockBukkit.unmock(); }
@@ -33,7 +34,7 @@ ItemCategory category(String id,int cost) {
         when(category.getIconItem(anyBoolean())).thenAnswer(call->{var icon=new ItemStack(Material.PAPER); var meta=icon.getItemMeta(); meta.getPersistentDataContainer().set(Keys.categoryId,PersistentDataType.STRING,id); meta.setDisplayName(id+(call.getArgument(0,Boolean.class)?" active":" inactive")); icon.setItemMeta(meta); return icon;});
         categories.add(category); byId.put(id,category); return category;
     }
-    InventoryClickEvent click(int slot) { var event=mock(InventoryClickEvent.class); when(event.getWhoClicked()).thenReturn(player); when(event.getView()).thenReturn(view); when(event.getClickedInventory()).thenReturn(inventory); when(event.getSlot()).thenReturn(slot); if(slot>=0 && slot<inventory.getSize()) when(event.getCurrentItem()).thenReturn(inventory.getItem(slot)); return event; }
+    InventoryClickEvent click(int slot) { var event=mock(InventoryClickEvent.class); when(event.getWhoClicked()).thenReturn(player); when(event.getView()).thenReturn(view); when(event.getClickedInventory()).thenReturn(inventory); when(event.getSlot()).thenReturn(slot); if(slot>=0 && slot<inventory.getSize()) { var item=inventory.getItem(slot); when(event.getCurrentItem()).thenReturn(item); } return event; }
     @Test void confirmChargesOnlyNewSelectionsAndCancelDiscardsDraft() {
         category("saved",5); category("new",7); data.setActiveCategories(new ArrayList<>(List.of("saved"))); data.setPoints(10);
         manager.openLoadout(player); var holder=(LoadoutHolder)inventory.getHolder(); assertEquals(player.getUniqueId(),holder.getPlayerId()); assertEquals(0,holder.getPage()); assertNull(holder.getInventory()); assertEquals(54,inventory.getSize());
@@ -62,8 +63,8 @@ ItemCategory category(String id,int cost) {
     }
     @Test void otherOwnersAndOtherMenusAreIgnoredByClickAndCloseHandlers() {
         category("one",1); manager.openLoadout(player); var event=click(0); var close=mock(InventoryCloseEvent.class); when(close.getPlayer()).thenReturn(player); when(close.getView()).thenReturn(view);
-        var other=MockBukkit.getMock().createInventory(new LoadoutHolder(UUID.randomUUID(),0),54); when(view.getTopInventory()).thenReturn(other); manager.onInventoryClick(event); manager.onInventoryClose(close); verify(event,never()).setCancelled(true);
-        when(view.getTopInventory()).thenReturn(MockBukkit.getMock().createInventory(null,9)); manager.onInventoryClick(event); manager.onInventoryClose(close); verify(event,never()).setCancelled(true);
+        var other=TestInventories.withHolderLookup(MockBukkit.getMock().createInventory(new LoadoutHolder(UUID.randomUUID(),0),54)); when(view.getTopInventory()).thenReturn(other); manager.onInventoryClick(event); manager.onInventoryClose(close); verify(event,never()).setCancelled(true);
+        var menu=TestInventories.withHolderLookup(MockBukkit.getMock().createInventory(null,9)); when(view.getTopInventory()).thenReturn(menu); manager.onInventoryClick(event); manager.onInventoryClose(close); verify(event,never()).setCancelled(true);
         when(close.getPlayer()).thenReturn(mock(HumanEntity.class)); manager.onInventoryClose(close);
         when(view.getTopInventory()).thenReturn(inventory); manager.onInventoryClick(click(0)); manager.onInventoryClick(click(49)); assertEquals(List.of("one"),data.getActiveCategories());
     }

src/test/java/net/tfminecraft/thievery/steal/StealGuiTest.java

@@ -131,10 +131,10 @@ void robberyAlwaysReservesPouchSlot(int count) {
         UUID id=UUID.randomUUID(); var holder=new StealGuiHolder(id,StealGuiHolder.Kind.CHEST); var player=mock(Player.class,RETURNS_DEEP_STUBS);
         StealGui.updateTitle(null,holder,"new"); StealGui.updateTitle(player,holder,"new"); verify(player,never()).getOpenInventory();
         when(player.isOnline()).thenReturn(true); StealGui.updateTitle(player,null,"new"); StealGui.updateTitle(player,holder,null); verify(player,never()).getOpenInventory();
-        var view=player.getOpenInventory(); var top=view.getTopInventory(); when(top.getHolder()).thenReturn(null); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
-        when(top.getHolder()).thenReturn(new StealGuiHolder(UUID.randomUUID(),StealGuiHolder.Kind.CHEST)); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
-        when(top.getHolder()).thenReturn(new StealGuiHolder(id,StealGuiHolder.Kind.ROBBERY)); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
-        when(top.getHolder()).thenReturn(holder); when(view.getTitle()).thenReturn("new"); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
+        var view=player.getOpenInventory(); var top=view.getTopInventory(); when(top.getHolder(false)).thenReturn(null); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
+        when(top.getHolder(false)).thenReturn(new StealGuiHolder(UUID.randomUUID(),StealGuiHolder.Kind.CHEST)); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
+        when(top.getHolder(false)).thenReturn(new StealGuiHolder(id,StealGuiHolder.Kind.ROBBERY)); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
+        when(top.getHolder(false)).thenReturn(holder); when(view.getTitle()).thenReturn("new"); StealGui.updateTitle(player,holder,"new"); verify(view,never()).setTitle(anyString());
         when(view.getTitle()).thenReturn("old"); StealGui.updateTitle(player,holder,"new"); verify(view).setTitle("new");
     }
 }

src/test/java/net/tfminecraft/thievery/steal/StealManagerTest.java

@@ -37,18 +37,18 @@ class StealManagerTest {
         var manager=new StealManager(); UUID id=UUID.randomUUID(); var player=player(id); var reference=reference(id); manager.registerSession(reference);
         try(var bukkit=mockStatic(Bukkit.class)) {
             manager.tickAll(); verify(reference,never()).tick(any()); bukkit.when(()->Bukkit.getPlayer(id)).thenReturn(player); when(player.isOnline()).thenReturn(false); manager.tickAll(); verify(reference,never()).tick(any()); when(player.isOnline()).thenReturn(true);
-            var top=player.getOpenInventory().getTopInventory(); when(top.getHolder()).thenReturn(null); manager.tickAll();
-            when(top.getHolder()).thenReturn(new StealGuiHolder(id,StealGuiHolder.Kind.ROBBERY)); manager.tickAll();
-            when(top.getHolder()).thenReturn(new StealGuiHolder(UUID.randomUUID(),StealGuiHolder.Kind.CHEST)); manager.tickAll(); verify(reference,never()).tick(any());
-            when(top.getHolder()).thenReturn(new StealGuiHolder(id,StealGuiHolder.Kind.CHEST)); doAnswer(call->{manager.endSession(id,false); return null;}).when(reference).tick(player); manager.tickAll(); verify(reference).tick(player); assertFalse(manager.hasSession(id));
+            var top=player.getOpenInventory().getTopInventory(); when(top.getHolder(false)).thenReturn(null); manager.tickAll();
+            when(top.getHolder(false)).thenReturn(new StealGuiHolder(id,StealGuiHolder.Kind.ROBBERY)); manager.tickAll();
+            when(top.getHolder(false)).thenReturn(new StealGuiHolder(UUID.randomUUID(),StealGuiHolder.Kind.CHEST)); manager.tickAll(); verify(reference,never()).tick(any());
+            when(top.getHolder(false)).thenReturn(new StealGuiHolder(id,StealGuiHolder.Kind.CHEST)); doAnswer(call->{manager.endSession(id,false); return null;}).when(reference).tick(player); manager.tickAll(); verify(reference).tick(player); assertFalse(manager.hasSession(id));
         }
     }
     @Test void clickAndCloseEventsDispatchOnlyPlayerTheftInventoriesWithMatchingSessionKind() {
         var manager=new StealManager(); UUID id=UUID.randomUUID(); var player=player(id); var reference=reference(id);
         var click=mock(InventoryClickEvent.class,RETURNS_DEEP_STUBS); var close=mock(InventoryCloseEvent.class,RETURNS_DEEP_STUBS);
         var nonplayer=mock(HumanEntity.class); when(click.getWhoClicked()).thenReturn(nonplayer); when(close.getPlayer()).thenReturn(nonplayer); manager.onInventoryClick(click); manager.onInventoryClose(close);
-        when(click.getWhoClicked()).thenReturn(player); when(close.getPlayer()).thenReturn(player); when(click.getView().getTopInventory().getHolder()).thenReturn(null); when(close.getView().getTopInventory().getHolder()).thenReturn(null); manager.onInventoryClick(click); manager.onInventoryClose(close);
-        var holder=new StealGuiHolder(id,StealGuiHolder.Kind.CHEST); when(click.getView().getTopInventory().getHolder()).thenReturn(holder); when(close.getView().getTopInventory().getHolder()).thenReturn(holder); manager.onInventoryClick(click); manager.onInventoryClose(close);
+        when(click.getWhoClicked()).thenReturn(player); when(close.getPlayer()).thenReturn(player); when(click.getView().getTopInventory().getHolder(false)).thenReturn(null); when(close.getView().getTopInventory().getHolder(false)).thenReturn(null); manager.onInventoryClick(click); manager.onInventoryClose(close);
+        var holder=new StealGuiHolder(id,StealGuiHolder.Kind.CHEST); when(click.getView().getTopInventory().getHolder(false)).thenReturn(holder); when(close.getView().getTopInventory().getHolder(false)).thenReturn(holder); manager.onInventoryClick(click); manager.onInventoryClose(close);
         manager.registerSession(reference); when(reference.getKind()).thenReturn(StealGuiHolder.Kind.ROBBERY); manager.onInventoryClick(click); manager.onInventoryClose(close); verify(reference,never()).handleClick(any(),any()); verify(reference,never()).onClose(any());
         when(reference.getKind()).thenReturn(StealGuiHolder.Kind.CHEST); manager.onInventoryClick(click); verify(reference).handleClick(click,player); manager.onInventoryClose(close); verify(reference).onClose(player); assertFalse(manager.hasSession(id));
         assertNull(StealManager.getStealGuiHolder(null)); assertSame(holder,StealManager.getStealGuiHolder(click.getView().getTopInventory()));