Core/DBLayer: Add nicer api for SQLQueryHolders

src/server/game/Server/WorldSession.cpp

@@ -1124,13 +1124,7 @@ void WorldSession::ProcessQueryCallbacks()
 {
     _queryProcessor.ProcessReadyCallbacks();
     _transactionCallbacks.ProcessReadyCallbacks();
-
-    if (_realmAccountLoginCallback.valid() && _realmAccountLoginCallback.wait_for(std::chrono::seconds(0)) == std::future_status::ready)
-        InitializeSessionCallback(static_cast<LoginDatabaseQueryHolder*>(_realmAccountLoginCallback.get()));
-
-    //! HandlePlayerLoginOpcode
-    if (_charLoginCallback.valid() && _charLoginCallback.wait_for(std::chrono::seconds(0)) == std::future_status::ready)
-        HandlePlayerLogin(reinterpret_cast<LoginQueryHolder*>(_charLoginCallback.get()));
+    _queryHolderProcessor.ProcessReadyCallbacks();
 }
 
 TransactionCallback& WorldSession::AddTransactionCallback(TransactionCallback&& callback)
@@ -1138,6 +1132,11 @@ TransactionCallback& WorldSession::AddTransactionCallback(TransactionCallback&&
     return _transactionCallbacks.AddCallback(std::move(callback));
 }
 
+SQLQueryHolderCallback& WorldSession::AddQueryHolderCallback(SQLQueryHolderCallback&& callback)
+{
+    return _queryHolderProcessor.AddCallback(std::move(callback));
+}
+
 void WorldSession::InitWarden(BigNumber* k, std::string const& os)
 {
     if (os == "Win")
@@ -1213,10 +1212,13 @@ void WorldSession::InitializeSession()
         return;
     }
 
-    _realmAccountLoginCallback = CharacterDatabase.DelayQueryHolder(realmHolder);
+    AddQueryHolderCallback(CharacterDatabase.DelayQueryHolder(realmHolder)).AfterComplete([this](SQLQueryHolderBase* holder)
+    {
+        InitializeSessionCallback(static_cast<AccountInfoQueryHolderPerRealm*>(holder));
+    });
 }
 
-void WorldSession::InitializeSessionCallback(LoginDatabaseQueryHolder* realmHolder)
+void WorldSession::InitializeSessionCallback(CharacterDatabaseQueryHolder* realmHolder)
 {
     LoadAccountData(realmHolder->GetPreparedResult(AccountInfoQueryHolderPerRealm::GLOBAL_ACCOUNT_DATA), GLOBAL_CACHE_MASK);
     LoadTutorialsData(realmHolder->GetPreparedResult(AccountInfoQueryHolderPerRealm::TUTORIALS));