- recognize that do_rollback() and do_commit() work with a DBAPI connection,

whereas the other do_rollback_twophase(), savepoint etc. work with
:class:`.Connection`.  the context on these are different as twophase/savepoint
are available at the :class:`.Connection` level, whereas commit/rollback are needed
at a lower level as well.  Rename the argument to "dbapi_connection" when the conneciton
is in fact the DBAPI interface.
- start thinking about being able to track "autocommit" vs. "commit", but not sure
we have a need for this yet.
- have Pool call out to a Dialect for all rollback/commit/close operations now.  Pool
no longer calls DBAPI methods directly.  May use this for a workaround for [ticket:2611]
- add a new Pool event reset() to allow the pool's reset of the connection to be intercepted.
- remove methods in Informix dialect which appear to be hardcoding some isolation
settings on new Transaction only; the isolation API should be implemented for Informix.
also removed "flag" for transaction commit/rollback being not available; this should
be based on server/DBAPI version and we will need someone with test access in order
to help determine how this should work

1 files changed, 50 insertions, 2 deletions

diff --git a/lib/sqlalchemy/events.py b/lib/sqlalchemy/events.py
index 07661c919..5d2665779 100644
--- a/lib/sqlalchemy/events.py
+++ b/lib/sqlalchemy/events.py
@@ -336,6 +336,37 @@ class PoolEvents(event.Events):
 
         """
 
+    def reset(self, dbapi_con, con_record):
+        """Called before the "reset" action occurs for a pooled connection.
+
+        This event represents
+        when the ``rollback()`` method is called on the DBAPI connection
+        before it is returned to the pool.  The behavior of "reset" can
+        be controlled, including disabled, using the ``reset_on_return``
+        pool argument.
+
+
+        The :meth:`.PoolEvents.reset` event is usually followed by the
+        the :meth:`.PoolEvents.checkin` event is called, except in those
+        cases where the connection is discarded immediately after reset.
+
+        :param dbapi_con:
+          A raw DB-API connection
+
+        :param con_record:
+          The ``_ConnectionRecord`` that persistently manages the connection
+
+        .. versionadded:: 0.8
+
+        .. seealso::
+
+            :meth:`.ConnectionEvents.rollback`
+
+            :meth:`.ConnectionEvents.commit`
+
+        """
+
+
 
 class ConnectionEvents(event.Events):
     """Available events for :class:`.Connectable`, which includes
@@ -592,14 +623,31 @@ class ConnectionEvents(event.Events):
         """
 
     def rollback(self, conn):
-        """Intercept rollback() events.
+        """Intercept rollback() events, as initiated by a
+        :class:`.Transaction`.
+
+        Note that the :class:`.Pool` also "auto-rolls back"
+        a DBAPI connection upon checkin, if the ``reset_on_return``
+        flag is set to its default value of ``'rollback'``.
+        To intercept this
+        rollback, use the :meth:`.PoolEvents.reset` hook.
 
         :param conn: :class:`.Connection` object
 
+        .. seealso::
+
+            :meth:`.PoolEvents.reset`
+
         """
 
     def commit(self, conn):
-        """Intercept commit() events.
+        """Intercept commit() events, as initiated by a
+        :class:`.Transaction`.
+
+        Note that the :class:`.Pool` may also "auto-commit"
+        a DBAPI connection upon checkin, if the ``reset_on_return``
+        flag is set to the value ``'commit'``.  To intercept this
+        commit, use the :meth:`.PoolEvents.reset` hook.
 
         :param conn: :class:`.Connection` object
         """