database: add static variables to prevent having multiple sessions

core/data/database.py

@@ -15,6 +15,13 @@ from core.utils import Utils
 
 
 class Data:
+    current_schema_version = 4
+    engine = None
+    session = None
+    user = None
+    arcade = None
+    card = None
+    base = None
     def __init__(self, cfg: CoreConfig) -> None:
         self.config = cfg
 
@@ -24,22 +31,32 @@ class Data:
         else:
             self.__url = f"{self.config.database.protocol}://{self.config.database.username}:{self.config.database.password}@{self.config.database.host}/{self.config.database.name}?charset=utf8mb4"
 
-        self.__engine = create_engine(self.__url, pool_recycle=3600)
-        session = sessionmaker(bind=self.__engine, autoflush=True, autocommit=True)
-        self.session = scoped_session(session)
+        if Data.engine is None:
+            Data.engine = create_engine(self.__url, pool_recycle=3600)
+            self.__engine = Data.engine
 
-        self.user = UserData(self.config, self.session)
-        self.arcade = ArcadeData(self.config, self.session)
-        self.card = CardData(self.config, self.session)
-        self.base = BaseData(self.config, self.session)
-        self.current_schema_version = 4
+        if Data.session is None:
+            s = sessionmaker(bind=Data.engine, autoflush=True, autocommit=True)
+            Data.session = scoped_session(s)
+
+        if Data.user is None:
+            Data.user = UserData(self.config, self.session)
+        
+        if Data.arcade is None:
+            Data.arcade = ArcadeData(self.config, self.session)
+        
+        if Data.card is None:
+            Data.card = CardData(self.config, self.session)
+        
+        if Data.base is None:
+            Data.base = BaseData(self.config, self.session)
 
-        log_fmt_str = "[%(asctime)s] %(levelname)s | Database | %(message)s"
-        log_fmt = logging.Formatter(log_fmt_str)
         self.logger = logging.getLogger("database")
 
         # Prevent the logger from adding handlers multiple times
         if not getattr(self.logger, "handler_set", None):            
+            log_fmt_str = "[%(asctime)s] %(levelname)s | Database | %(message)s"
+            log_fmt = logging.Formatter(log_fmt_str)
             fileHandler = TimedRotatingFileHandler(
                 "{0}/{1}.log".format(self.config.server.log_dir, "db"),
                 encoding="utf-8",