- refactor pool a bit so that intent between ConnectionRecord/ConnectionFairy is clear;

make sure that the DBAPI connection passed to the reset-on-return events/dialect hooks
is also a "fairy", so that dictionaries like "info" are available.  [ticket:2770]
- rework the execution_options system so that the dialect is given the job of making
any immediate adjustments based on a set event.  move the "isolation level" logic to use
this new system.   Also work things out so that even engine-level execution options
can be used for things like isolation level; the dialect attaches a connect-event
handler in this case to handle the task.
- to support this new system as well as further extensibiltiy of execution options
add events engine_connect(), set_connection_execution_options(), set_engine_execution_options()

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py
index 2ad7002c4..3e8e96a42 100644
--- a/lib/sqlalchemy/engine/default.py
+++ b/lib/sqlalchemy/engine/default.py
@@ -19,6 +19,7 @@ from ..sql import compiler, expression
 from .. import exc, types as sqltypes, util, pool, processors
 import codecs
 import weakref
+from .. import event
 
 AUTOCOMMIT_REGEXP = re.compile(
             r'\s*(?:UPDATE|INSERT|CREATE|DELETE|DROP|ALTER)',
@@ -289,6 +290,24 @@ class DefaultDialect(interfaces.Dialect):
         opts.update(url.query)
         return [[], opts]
 
+    def set_engine_execution_options(self, engine, opts):
+        if 'isolation_level' in opts:
+            isolation_level = opts['isolation_level']
+            @event.listens_for(engine, "engine_connect")
+            def set_isolation(connection, branch):
+                if not branch:
+                    self._set_connection_isolation(connection, isolation_level)
+
+    def set_connection_execution_options(self, connection, opts):
+        if 'isolation_level' in opts:
+            self._set_connection_isolation(connection, opts['isolation_level'])
+
+    def _set_connection_isolation(self, connection, level):
+        self.set_isolation_level(connection.connection, level)
+        connection.connection._connection_record.\
+            finalize_callback.append(self.reset_isolation_level)
+
+
     def do_begin(self, dbapi_connection):
         pass