Read NPC building owners once instead of per building at boot

Building.runAfterLoad ran GET_UID_ENUM for every building (~47k queries).
One query now reads the NPC owner IDs before the building load; runtime
loads also check the NPC cache. City load reads ownerIsNPC before NPCs
are cached, so a pass after the NPC load would not work.

Value changes: none. ownerIsNPC is still true exactly when the owner's
object.type is 'npc' (dev DB: 388 buildings, 24 owners).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/db/handlers/dbBuildingHandler.java

@@ -28,6 +28,7 @@ import java.time.LocalDateTime;
 import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.concurrent.ConcurrentHashMap;
 
 public class dbBuildingHandler extends dbHandlerBase {
@@ -100,6 +101,26 @@ public class dbBuildingHandler extends dbHandlerBase {
         return buildings;
     }
 
+    public HashSet<Integer> GET_NPC_BUILDING_OWNERS() {
+
+        HashSet<Integer> npcOwners = new HashSet<>();
+
+        try (Connection connection = DbManager.getConnection();
+             PreparedStatement preparedStatement = connection.prepareStatement("SELECT DISTINCT `obj_building`.`ownerUUID` FROM `obj_building` INNER JOIN `object` ON `object`.`UID` = `obj_building`.`ownerUUID` WHERE `object`.`type` = 'npc';")) {
+
+            ResultSet rs = preparedStatement.executeQuery();
+
+            while (rs.next())
+                npcOwners.add(rs.getInt("ownerUUID"));
+
+        } catch (SQLException e) {
+            Logger.error(e);
+        }
+
+        Logger.info("read: " + npcOwners.size() + " NPC building owners");
+        return npcOwners;
+    }
+
     public Building GET_BUILDINGBYUUID(int uuid) {
 
         if (uuid == 0)

src/engine/gameManager/BuildingManager.java

@@ -31,6 +31,7 @@ import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.EnumSet;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ThreadLocalRandom;
 
@@ -44,6 +45,7 @@ public enum BuildingManager {
     public static HashMap<Integer, ConcurrentHashMap<Integer, BuildingFriends>> _buildingFriends = new HashMap<>();
     public static HashMap<Integer, ConcurrentHashMap<Integer, Condemned>> _buildingCondemned = new HashMap<>();
     public static HashMap<Integer, ArrayList<Vector3fImmutable>> _buildingPatrolPoints = new HashMap<>();
+    public static HashSet<Integer> _npcBuildingOwners = new HashSet<>();
 
     public static int getAvailableSlot(Building building) {
 

src/engine/objects/Building.java

@@ -1027,15 +1027,10 @@ public class Building extends AbstractWorldObject {
             }
         }
 
-        // Submit upgrade job if building is currently set to rank.
+        // City load reads ownerIsNPC before NPCs are cached, so boot uses the owner set read ahead of buildings.
 
-        try {
-            DbObjectType objectType = DbManager.BuildingQueries.GET_UID_ENUM(this.ownerUUID);
-            this.ownerIsNPC = (objectType == DbObjectType.NPC);
-        } catch (Exception e) {
-            this.ownerIsNPC = false;
-            Logger.error("Failed to find Object Type for owner " + this.ownerUUID + " Location " + this.getLoc().toString());
-        }
+        this.ownerIsNPC = BuildingManager._npcBuildingOwners.contains(this.ownerUUID)
+                || DbManager.inCache(GameObjectType.NPC, this.ownerUUID);
 
         // Reference friend and condemn lists from BuildingManager
 

src/engine/server/world/WorldServer.java

@@ -529,6 +529,7 @@ public class WorldServer {
         Logger.info("Loading all Zones");
         DbManager.ZoneQueries.GET_ALL_ZONES();
         Logger.info("Loading all Buildings");
+        BuildingManager._npcBuildingOwners = DbManager.BuildingQueries.GET_NPC_BUILDING_OWNERS();
         DbManager.BuildingQueries.GET_ALL_BUILDINGS();
         Logger.info("Loading all Cities");
         DbManager.CityQueries.GET_ALL_CITIES();