feat(Core): GUID recycler (#1820)

Automatically recycle GUIDs, thus avoiding crashes when reaching the
limit of data type "int" in MySQL.

src/server/game/Globals/ObjectMgr.cpp

@@ -6198,7 +6198,12 @@ void ObjectMgr::SetHighestGuids()
 
     result = WorldDatabase.Query("SELECT MAX(guid) FROM creature");
     if (result)
+    {
         _hiCreatureGuid = (*result)[0].GetUInt32()+1;
+        _hiCreatureRecycledGuid = _hiCreatureGuid;
+        _hiCreatureRecycledGuidMax = _hiCreatureRecycledGuid + 10000;
+        _hiCreatureGuid = _hiCreatureRecycledGuidMax + 1;
+    }
 
     result = CharacterDatabase.Query("SELECT MAX(guid) FROM item_instance");
     if (result)
@@ -6212,7 +6217,12 @@ void ObjectMgr::SetHighestGuids()
 
     result = WorldDatabase.Query("SELECT MAX(guid) FROM gameobject");
     if (result)
+    {
         _hiGoGuid = (*result)[0].GetUInt32()+1;
+        _hiGoRecycledGuid = _hiGoGuid;
+        _hiGoRecycledGuidMax = _hiGoRecycledGuid + 1;
+        _hiGoGuid = _hiGoRecycledGuidMax + 1;
+    }
 
     result = WorldDatabase.Query("SELECT MAX(guid) FROM transports");
     if (result)
@@ -6341,6 +6351,31 @@ uint32 ObjectMgr::GenerateLowGuid(HighGuid guidhigh)
     }
 }
 
+uint32 ObjectMgr::GenerateRecycledLowGuid(HighGuid guidHigh)
+{
+    switch (guidHigh)
+    {
+        case HIGHGUID_UNIT:
+        {
+            ASSERT(_hiCreatureRecycledGuid < 0x00FFFFFE && "Creature recycled guid overflow!");
+            if (_hiCreatureRecycledGuid < _hiCreatureRecycledGuidMax)
+                return _hiCreatureRecycledGuid++;
+            break;
+        }
+        case HIGHGUID_GAMEOBJECT:
+        {
+            ASSERT(_hiGoRecycledGuid < 0x00FFFFFE && "Gameobject recycled guid overflow!");
+            if (_hiGoRecycledGuid < _hiGoRecycledGuidMax)
+                return _hiGoRecycledGuid++;
+            break;
+        }
+        default: // Default case is not handled by the recycler
+            break;
+    }
+
+    return GenerateLowGuid(guidHigh);
+}
+
 void ObjectMgr::LoadGameObjectLocales()
 {
     uint32 oldMSTime = getMSTime();

src/server/game/Globals/ObjectMgr.h

@@ -1057,6 +1057,7 @@ class ObjectMgr
 
         void SetHighestGuids();
         uint32 GenerateLowGuid(HighGuid guidhigh);
+        uint32 GenerateRecycledLowGuid(HighGuid guidHigh);
         uint32 GenerateAuctionID();
         uint64 GenerateEquipmentSetGuid();
         uint32 GenerateMailID();
@@ -1354,6 +1355,11 @@ class ObjectMgr
         uint32 _hiCorpseGuid; ACE_Thread_Mutex _hiCorpseGuidMutex;
         uint32 _hiMoTransGuid; ACE_Thread_Mutex _hiMoTransGuidMutex;
 
+        uint32 _hiCreatureRecycledGuidMax;
+        uint32 _hiCreatureRecycledGuid;
+        uint32 _hiGoRecycledGuidMax;
+        uint32 _hiGoRecycledGuid;
+
         QuestMap _questTemplates;
         std::vector<Quest*> _questTemplatesFast; // pussywizard
 

src/server/scripts/Commands/cs_gobject.cpp

@@ -137,7 +137,7 @@ public:
         Map* map = player->GetMap();
 
         GameObject* object = sObjectMgr->IsGameObjectStaticTransport(objectInfo->entry) ? new StaticTransport() : new GameObject();
-        uint32 guidLow = sObjectMgr->GenerateLowGuid(HIGHGUID_GAMEOBJECT);
+        uint32 guidLow = sObjectMgr->GenerateRecycledLowGuid(HIGHGUID_GAMEOBJECT);
 
         if (!object->Create(guidLow, objectInfo->entry, map, player->GetPhaseMaskForSpawn(), x, y, z, o, G3D::Quat(), 0, GO_STATE_READY))
         {

src/server/scripts/Commands/cs_npc.cpp

@@ -212,7 +212,7 @@ public:
         if (Transport* tt = chr->GetTransport())
             if (MotionTransport* trans = tt->ToMotionTransport())
             {
-                uint32 guid = sObjectMgr->GenerateLowGuid(HIGHGUID_UNIT);
+                uint32 guid = sObjectMgr->GenerateRecycledLowGuid(HIGHGUID_UNIT);
                 CreatureData& data = sObjectMgr->NewOrExistCreatureData(guid);
                 data.id = id;
                 data.phaseMask = chr->GetPhaseMaskForSpawn();
@@ -230,7 +230,7 @@ public:
             }
 
         Creature* creature = new Creature();
-        if (!creature->Create(sObjectMgr->GenerateLowGuid(HIGHGUID_UNIT), map, chr->GetPhaseMaskForSpawn(), id, 0, x, y, z, o))
+        if (!creature->Create(sObjectMgr->GenerateRecycledLowGuid(HIGHGUID_UNIT), map, chr->GetPhaseMaskForSpawn(), id, 0, x, y, z, o))
         {
             delete creature;
             return false;