🆙 Database performance fixes

1. HabboManager - O(1) username lookup
Before: getHabbo(String) held a synchronized lock and iterated ALL online users every call
After: Secondary ConcurrentHashMap<String, Habbo> keyed by lowercase username → instant get() lookup, no lock contention

2. ItemsComponent - Batch DB saves
Before: dispose() spawned a separate thread per dirty item, each opening its own DB connection
After: Single connection, JDBC addBatch()/executeBatch() for both UPDATE and DELETE, flushed every 100 items. A user with 500 dirty items now does 5 batch executions instead of 500 thread spawns + 500 connections.

3. AcceptFriendRequestEvent - N+1 elimination
Before: For each offline user: query 1 (getOfflineHabboInfo by ID) → query 2 (load full Habbo by username) = 2 queries × up to 100 users = 200 queries
After: Single query by user ID directly = 1 query × up to 100 users = 100 queries (50% reduction)

4. RoomManager - Direct HashMap lookup
Before: getCategory(int id) iterated all categories checking getId() == id even though the map is already keyed by ID
After: Direct roomCategories.get(id) → O(1) instead of O(n)

Emulator/src/main/java/com/eu/habbo/habbohotel/rooms/RoomManager.java

@@ -179,12 +179,7 @@ public class RoomManager {
     }
 
     public RoomCategory getCategory(int id) {
-        for (RoomCategory category : this.roomCategories.values()) {
+        return this.roomCategories.get(id);
-            if (category.getId() == id)
-                return category;
-        }
-
-        return null;
     }
 
     public RoomCategory getCategory(String name) {
@@ -220,15 +215,8 @@ public class RoomManager {
     }
 
     public boolean hasCategory(int categoryId, Habbo habbo) {
-        for (RoomCategory category : this.roomCategories.values()) {
+        RoomCategory category = this.roomCategories.get(categoryId);
-            if (category.getId() == categoryId) {
+        return category != null && category.getMinRank() <= habbo.getHabboInfo().getRank().getId();
-                if (category.getMinRank() <= habbo.getHabboInfo().getRank().getId()) {
-                    return true;
-                }
-            }
-        }
-
-        return false;
     }
 
     public THashMap<Integer, RoomCategory> getRoomCategories() {

Emulator/src/main/java/com/eu/habbo/habbohotel/users/HabboManager.java

@@ -35,11 +35,13 @@ public class HabboManager {
     public static boolean NAMECHANGE_ENABLED = false;
 
     private final ConcurrentHashMap<Integer, Habbo> onlineHabbos;
+    private final ConcurrentHashMap<String, Habbo> onlineHabbosByName;
 
     public HabboManager() {
         long millis = System.currentTimeMillis();
 
         this.onlineHabbos = new ConcurrentHashMap<>();
+        this.onlineHabbosByName = new ConcurrentHashMap<>();
 
         LOGGER.info("Habbo Manager -> Loaded! ({} MS)", System.currentTimeMillis() - millis);
     }
@@ -80,10 +82,12 @@ public class HabboManager {
 
     public void addHabbo(Habbo habbo) {
         this.onlineHabbos.put(habbo.getHabboInfo().getId(), habbo);
+        this.onlineHabbosByName.put(habbo.getHabboInfo().getUsername().toLowerCase(), habbo);
     }
 
     public void removeHabbo(Habbo habbo) {
         this.onlineHabbos.remove(habbo.getHabboInfo().getId());
+        this.onlineHabbosByName.remove(habbo.getHabboInfo().getUsername().toLowerCase());
     }
 
     public Habbo getHabbo(int id) {
@@ -91,14 +95,7 @@ public class HabboManager {
     }
 
     public Habbo getHabbo(String username) {
-        synchronized (this.onlineHabbos) {
+        return this.onlineHabbosByName.get(username.toLowerCase());
-            for (Map.Entry<Integer, Habbo> map : this.onlineHabbos.entrySet()) {
-                if (map.getValue().getHabboInfo().getUsername().equalsIgnoreCase(username))
-                    return map.getValue();
-            }
-        }
-
-        return null;
     }
 
     public Habbo loadHabbo(String sso) {
@@ -178,14 +175,12 @@ public class HabboManager {
     }
 
     public void sendPacketToHabbosWithPermission(ServerMessage message, String perm) {
-        synchronized (this.onlineHabbos) {
         for (Habbo habbo : this.onlineHabbos.values()) {
             if (habbo.hasPermission(perm)) {
                 habbo.getClient().sendResponse(message);
             }
         }
     }
-    }
 
     public ConcurrentHashMap<Integer, Habbo> getOnlineHabbos() {
         return this.onlineHabbos;

Emulator/src/main/java/com/eu/habbo/habbohotel/users/inventory/ItemsComponent.java

@@ -159,14 +159,63 @@ public class ItemsComponent {
             }
 
             if (!this.items.isEmpty()) {
+                try (Connection connection = Emulator.getDatabase().getDataSource().getConnection()) {
+                    try (PreparedStatement updateStmt = connection.prepareStatement(
+                            "UPDATE items SET user_id = ?, room_id = ?, wall_pos = ?, x = ?, y = ?, z = ?, rot = ?, extra_data = ?, limited_data = ? WHERE id = ?")) {
+                        try (PreparedStatement deleteStmt = connection.prepareStatement(
+                                "DELETE FROM items WHERE id = ?")) {
+
+                            int updateCount = 0;
+                            int deleteCount = 0;
+
                             for (int i = this.items.size(); i-- > 0; ) {
                                 try {
                                     items.advance();
                                 } catch (NoSuchElementException e) {
                                     break;
                                 }
-                    if (items.value().needsUpdate())
+
-                        Emulator.getThreading().run(items.value());
+                                HabboItem item = items.value();
+                                if (item.needsDelete()) {
+                                    deleteStmt.setInt(1, item.getId());
+                                    deleteStmt.addBatch();
+                                    deleteCount++;
+                                    item.needsUpdate(false);
+                                    item.needsDelete(false);
+                                } else if (item.needsUpdate()) {
+                                    updateStmt.setInt(1, item.getUserId());
+                                    updateStmt.setInt(2, item.getRoomId());
+                                    updateStmt.setString(3, item.getWallPosition());
+                                    updateStmt.setInt(4, item.getX());
+                                    updateStmt.setInt(5, item.getY());
+                                    updateStmt.setDouble(6, item.getZ());
+                                    updateStmt.setInt(7, item.getRotation());
+                                    updateStmt.setString(8, item.getExtradata());
+                                    updateStmt.setString(9, item.getLimitedStack() + ":" + item.getLimitedSells());
+                                    updateStmt.setInt(10, item.getId());
+                                    updateStmt.addBatch();
+                                    updateCount++;
+                                    item.needsUpdate(false);
+                                }
+
+                                if (updateCount > 0 && updateCount % 100 == 0) {
+                                    updateStmt.executeBatch();
+                                }
+                                if (deleteCount > 0 && deleteCount % 100 == 0) {
+                                    deleteStmt.executeBatch();
+                                }
+                            }
+
+                            if (deleteCount % 100 != 0) {
+                                deleteStmt.executeBatch();
+                            }
+                            if (updateCount % 100 != 0) {
+                                updateStmt.executeBatch();
+                            }
+                        }
+                    }
+                } catch (SQLException e) {
+                    LOGGER.error("Caught SQL exception during batch item save", e);
                 }
             }
 

Emulator/src/main/java/com/eu/habbo/messages/incoming/friends/AcceptFriendRequestEvent.java

@@ -3,7 +3,6 @@ package com.eu.habbo.messages.incoming.friends;
 import com.eu.habbo.Emulator;
 import com.eu.habbo.habbohotel.messenger.Messenger;
 import com.eu.habbo.habbohotel.users.Habbo;
-import com.eu.habbo.habbohotel.users.HabboInfo;
 import com.eu.habbo.messages.incoming.MessageHandler;
 import com.eu.habbo.messages.outgoing.friends.FriendRequestErrorComposer;
 import org.slf4j.Logger;
@@ -14,7 +13,6 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 
-import static com.eu.habbo.habbohotel.users.HabboManager.getOfflineHabboInfo;
 
 public class AcceptFriendRequestEvent extends MessageHandler {
     private static final Logger LOGGER = LoggerFactory.getLogger(AcceptFriendRequestEvent.class);
@@ -44,18 +42,10 @@ public class AcceptFriendRequestEvent extends MessageHandler {
             Habbo target = Emulator.getGameEnvironment().getHabboManager().getHabbo(userId);
 
             if(target == null) {
-                HabboInfo habboInfo = getOfflineHabboInfo(userId);
+                try (Connection connection = Emulator.getDatabase().getDataSource().getConnection(); PreparedStatement statement = connection.prepareStatement("SELECT users.*, users_settings.block_friendrequests FROM users INNER JOIN users_settings ON users.id = users_settings.user_id WHERE users.id = ? LIMIT 1")) {
-
+                    statement.setInt(1, userId);
-                if(habboInfo == null) {
-                    this.client.sendResponse(new FriendRequestErrorComposer(FriendRequestErrorComposer.TARGET_NOT_FOUND));
-                    this.client.getHabbo().getMessenger().deleteFriendRequests(userId, this.client.getHabbo().getHabboInfo().getId());
-                    continue;
-                }
-
-                try (Connection connection = Emulator.getDatabase().getDataSource().getConnection(); PreparedStatement statement = connection.prepareStatement("SELECT users.*, users_settings.block_friendrequests FROM users INNER JOIN users_settings ON users.id = users_settings.user_id WHERE username = ? LIMIT 1")) {
-                    statement.setString(1, habboInfo.getUsername());
                     try (ResultSet set = statement.executeQuery()) {
-                        while (set.next()) {
+                        if (set.next()) {
                             target = new Habbo(set);
                         }
                     }