merged session from devin

1 files changed, 53 insertions, 0 deletions

diff --git a/nova/db/sqlalchemy/session.py b/nova/db/sqlalchemy/session.py
new file mode 100644
index 000000000..06e2ca8cd
--- /dev/null
+++ b/nova/db/sqlalchemy/session.py
@@ -0,0 +1,53 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from sqlalchemy import create_engine
+from sqlalchemy.orm import create_session
+from sqlalchemy.ext.declarative import declarative_base
+
+from nova import flags
+
+FLAGS = flags.FLAGS
+
+def managed_session(autocommit=True):
+    return SessionExecutionManager(autocommit=autocommit)
+
+
+class SessionExecutionManager:
+    _engine = None
+    _session = None
+    
+    def __init__(self, autocommit):
+        cls = SessionExecutionManager
+        if not cls._engine:
+            cls._engine = create_engine(FLAGS.sql_connection, echo=False)
+        self._session = create_session(bind=cls._engine,
+                                       autocommit=autocommit)
+                 
+        
+    def __enter__(self):
+        return self._session
+
+    def __exit__(self, type, value, traceback):
+        import pdb
+        if type or value or traceback:
+            pdb.set_trace()
+        # TODO(devcamcar): Rollback on exception.
+        # TODO(devcamcar): Log exceptions.
+        if self._session:
+            self._session.close()
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