You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
1.8 KiB
57 lines
1.8 KiB
import abc
|
|
|
|
from ..util import ABC
|
|
|
|
|
|
class ConnectionCharacteristic(ABC):
|
|
"""An abstract base for an object that can set, get and reset a
|
|
per-connection characteristic, typically one that gets reset when the
|
|
connection is returned to the connection pool.
|
|
|
|
transaction isolation is the canonical example, and the
|
|
``IsolationLevelCharacteristic`` implementation provides this for the
|
|
``DefaultDialect``.
|
|
|
|
The ``ConnectionCharacteristic`` class should call upon the ``Dialect`` for
|
|
the implementation of each method. The object exists strictly to serve as
|
|
a dialect visitor that can be placed into the
|
|
``DefaultDialect.connection_characteristics`` dictionary where it will take
|
|
effect for calls to :meth:`_engine.Connection.execution_options` and
|
|
related APIs.
|
|
|
|
.. versionadded:: 1.4
|
|
|
|
"""
|
|
|
|
__slots__ = ()
|
|
|
|
transactional = False
|
|
|
|
@abc.abstractmethod
|
|
def reset_characteristic(self, dialect, dbapi_conn):
|
|
"""Reset the characteristic on the connection to its default value."""
|
|
|
|
@abc.abstractmethod
|
|
def set_characteristic(self, dialect, dbapi_conn, value):
|
|
"""set characteristic on the connection to a given value."""
|
|
|
|
@abc.abstractmethod
|
|
def get_characteristic(self, dialect, dbapi_conn):
|
|
"""Given a DBAPI connection, get the current value of the
|
|
characteristic.
|
|
|
|
"""
|
|
|
|
|
|
class IsolationLevelCharacteristic(ConnectionCharacteristic):
|
|
transactional = True
|
|
|
|
def reset_characteristic(self, dialect, dbapi_conn):
|
|
dialect.reset_isolation_level(dbapi_conn)
|
|
|
|
def set_characteristic(self, dialect, dbapi_conn, value):
|
|
dialect.set_isolation_level(dbapi_conn, value)
|
|
|
|
def get_characteristic(self, dialect, dbapi_conn):
|
|
return dialect.get_isolation_level(dbapi_conn)
|