API refactor

venv/lib/python3.12/site-packages/sqlalchemy/engine/characteristics.py

@@ -1,3 +1,9 @@
+# engine/characteristics.py
+# Copyright (C) 2005-2025 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
 from __future__ import annotations
 
 import abc
@@ -6,6 +12,7 @@ from typing import Any
 from typing import ClassVar
 
 if typing.TYPE_CHECKING:
+    from .base import Connection
     from .interfaces import DBAPIConnection
     from .interfaces import Dialect
 
@@ -38,13 +45,30 @@ class ConnectionCharacteristic(abc.ABC):
     def reset_characteristic(
         self, dialect: Dialect, dbapi_conn: DBAPIConnection
     ) -> None:
-        """Reset the characteristic on the connection to its default value."""
+        """Reset the characteristic on the DBAPI connection to its default
+        value."""
 
     @abc.abstractmethod
     def set_characteristic(
         self, dialect: Dialect, dbapi_conn: DBAPIConnection, value: Any
     ) -> None:
-        """set characteristic on the connection to a given value."""
+        """set characteristic on the DBAPI connection to a given value."""
+
+    def set_connection_characteristic(
+        self,
+        dialect: Dialect,
+        conn: Connection,
+        dbapi_conn: DBAPIConnection,
+        value: Any,
+    ) -> None:
+        """set characteristic on the :class:`_engine.Connection` to a given
+        value.
+
+        .. versionadded:: 2.0.30 - added to support elements that are local
+           to the :class:`_engine.Connection` itself.
+
+        """
+        self.set_characteristic(dialect, dbapi_conn, value)
 
     @abc.abstractmethod
     def get_characteristic(
@@ -55,8 +79,22 @@ class ConnectionCharacteristic(abc.ABC):
 
         """
 
+    def get_connection_characteristic(
+        self, dialect: Dialect, conn: Connection, dbapi_conn: DBAPIConnection
+    ) -> Any:
+        """Given a :class:`_engine.Connection`, get the current value of the
+        characteristic.
+
+        .. versionadded:: 2.0.30 - added to support elements that are local
+           to the :class:`_engine.Connection` itself.
+
+        """
+        return self.get_characteristic(dialect, dbapi_conn)
+
 
 class IsolationLevelCharacteristic(ConnectionCharacteristic):
+    """Manage the isolation level on a DBAPI connection"""
+
     transactional: ClassVar[bool] = True
 
     def reset_characteristic(
@@ -73,3 +111,45 @@ class IsolationLevelCharacteristic(ConnectionCharacteristic):
         self, dialect: Dialect, dbapi_conn: DBAPIConnection
     ) -> Any:
         return dialect.get_isolation_level(dbapi_conn)
+
+
+class LoggingTokenCharacteristic(ConnectionCharacteristic):
+    """Manage the 'logging_token' option of a :class:`_engine.Connection`.
+
+    .. versionadded:: 2.0.30
+
+    """
+
+    transactional: ClassVar[bool] = False
+
+    def reset_characteristic(
+        self, dialect: Dialect, dbapi_conn: DBAPIConnection
+    ) -> None:
+        pass
+
+    def set_characteristic(
+        self, dialect: Dialect, dbapi_conn: DBAPIConnection, value: Any
+    ) -> None:
+        raise NotImplementedError()
+
+    def set_connection_characteristic(
+        self,
+        dialect: Dialect,
+        conn: Connection,
+        dbapi_conn: DBAPIConnection,
+        value: Any,
+    ) -> None:
+        if value:
+            conn._message_formatter = lambda msg: "[%s] %s" % (value, msg)
+        else:
+            del conn._message_formatter
+
+    def get_characteristic(
+        self, dialect: Dialect, dbapi_conn: DBAPIConnection
+    ) -> Any:
+        raise NotImplementedError()
+
+    def get_connection_characteristic(
+        self, dialect: Dialect, conn: Connection, dbapi_conn: DBAPIConnection
+    ) -> Any:
+        return conn._execution_options.get("logging_token", None)