use a full ConnectionCharacteristic for logging_token

Fixed issue in the
:paramref:`_engine.Connection.execution_options.logging_token` option,
where changing the value of ``logging_token`` on a connection that has
already logged messages would not be updated to reflect the new logging
token.  This in particular prevented the use of
:meth:`_orm.Session.connection` to change the option on the connection,
since the BEGIN logging message would already have been emitted.

Fixes: #11210
Change-Id: I0ddade3778215259a6eacde3a67e09d30bc3257b
(cherry picked from commit a124a593c86325389a92903d2b61f40c34f6d6e2)

diff --git a/doc/build/changelog/unreleased_20/11210.rst b/doc/build/changelog/unreleased_20/11210.rst
new file mode 100644 (file)
index 0000000..088f07d
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/11210.rst
@@ -0,0 +1,11 @@
+.. change::
+    :tags: bug, engine
+    :tickets: 11210
+
+    Fixed issue in the
+    :paramref:`_engine.Connection.execution_options.logging_token` option,
+    where changing the value of ``logging_token`` on a connection that has
+    already logged messages would not be updated to reflect the new logging
+    token.  This in particular prevented the use of
+    :meth:`_orm.Session.connection` to change the option on the connection,
+    since the BEGIN logging message would already have been emitted.

diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index 403ec452b9a2f2c947636c18c2529510722f3f83..83d1cc1317a17b6af857f299bf701508b7ba673a 100644 (file)
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -174,13 +174,9 @@ class Connection(ConnectionEventsTarget, inspection.Inspectable["Inspector"]):
         if self._has_events or self.engine._has_events:
             self.dispatch.engine_connect(self)
 
-    @util.memoized_property
-    def _message_formatter(self) -> Any:
-        if "logging_token" in self._execution_options:
-            token = self._execution_options["logging_token"]
-            return lambda msg: "[%s] %s" % (token, msg)
-        else:
-            return None
+    # this can be assigned differently via
+    # characteristics.LoggingTokenCharacteristic
+    _message_formatter: Any = None
 
     def _log_info(self, message: str, *arg: Any, **kw: Any) -> None:
         fmt = self._message_formatter

diff --git a/lib/sqlalchemy/engine/characteristics.py b/lib/sqlalchemy/engine/characteristics.py
index 7dd3a2f31e3f1320be5fd049f68aa9bb9463968f..97b17fbdfb64e3760fedfa474082496294e01d73 100644 (file)
--- a/lib/sqlalchemy/engine/characteristics.py
+++ b/lib/sqlalchemy/engine/characteristics.py
@@ -12,6 +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
 
@@ -44,13 +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(
@@ -61,8 +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(
@@ -79,3 +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)

diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py
index 90cafe4f4ba9ae33ba01750fd1888473163d776b..b8eacc032ed21a53df96abcee69321b68b9f3d25 100644 (file)
--- a/lib/sqlalchemy/engine/default.py
+++ b/lib/sqlalchemy/engine/default.py
@@ -168,7 +168,10 @@ class DefaultDialect(Dialect):
     tuple_in_values = False
 
     connection_characteristics = util.immutabledict(
-        {"isolation_level": characteristics.IsolationLevelCharacteristic()}
+        {
+            "isolation_level": characteristics.IsolationLevelCharacteristic(),
+            "logging_token": characteristics.LoggingTokenCharacteristic(),
+        }
     )
 
     engine_config_types: Mapping[str, Any] = util.immutabledict(
@@ -660,7 +663,7 @@ class DefaultDialect(Dialect):
         if connection.in_transaction():
             trans_objs = [
                 (name, obj)
-                for name, obj, value in characteristic_values
+                for name, obj, _ in characteristic_values
                 if obj.transactional
             ]
             if trans_objs:
@@ -673,8 +676,10 @@ class DefaultDialect(Dialect):
                 )
 
         dbapi_connection = connection.connection.dbapi_connection
-        for name, characteristic, value in characteristic_values:
-            characteristic.set_characteristic(self, dbapi_connection, value)
+        for _, characteristic, value in characteristic_values:
+            characteristic.set_connection_characteristic(
+                self, connection, dbapi_connection, value
+            )
         connection.connection._connection_record.finalize_callback.append(
             functools.partial(self._reset_characteristics, characteristics)
         )

diff --git a/test/engine/test_logging.py b/test/engine/test_logging.py
index a498ec85c8377bbd897948be49a0bff06faf3245..119d553320199e3d81954bf5e962dbe3c939f41d 100644 (file)
--- a/test/engine/test_logging.py
+++ b/test/engine/test_logging.py
@@ -990,6 +990,43 @@ class LoggingTokenTest(fixtures.TestBase):
         c2.close()
         c3.close()
 
+    def test_logging_token_option_connection_updates(self, token_engine):
+        """test #11210"""
+
+        eng = token_engine
+
+        c1 = eng.connect().execution_options(logging_token="my_name_1")
+
+        self._assert_token_in_execute(c1, "my_name_1")
+
+        c1.execution_options(logging_token="my_name_2")
+
+        self._assert_token_in_execute(c1, "my_name_2")
+
+        c1.execution_options(logging_token=None)
+
+        self._assert_no_tokens_in_execute(c1)
+
+        c1.close()
+
+    def test_logging_token_option_not_transactional(self, token_engine):
+        """test #11210"""
+
+        eng = token_engine
+
+        c1 = eng.connect()
+
+        with c1.begin():
+            self._assert_no_tokens_in_execute(c1)
+
+            c1.execution_options(logging_token="my_name_1")
+
+            self._assert_token_in_execute(c1, "my_name_1")
+
+        self._assert_token_in_execute(c1, "my_name_1")
+
+        c1.close()
+
     def test_logging_token_option_engine(self, token_engine):
         eng = token_engine