--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/openstack/neutron/files/evs/db/api.py	Mon Mar 31 16:44:02 2014 -0700
@@ -0,0 +1,71 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2014, Oracle and/or its affiliates. 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.
+#
+# @author: Girish Moodalbail, Oracle, Inc.
+#
+
+import sqlalchemy as sa
+from sqlalchemy.ext import declarative
+from sqlalchemy import orm
+
+from oslo.config import cfg
+
+from quantum.context import ContextBase
+from quantum.db import model_base
+
+
+EVS_DB_BASE = declarative.declarative_base(cls=model_base.QuantumBaseV2)
+EVS_DB_ENGINE = None
+EVS_DB_MAKER = None
+
+
+class EVSContext(ContextBase):
+    @property
+    def session(self):
+        return self._session
+
+    @session.setter
+    def session(self, session):
+        self._session = session
+
+
+def configure_db():
+    global EVS_DB_ENGINE
+    if not EVS_DB_ENGINE:
+        sql_connection = cfg.CONF.DATABASE.sql_connection
+        if not sql_connection:
+            sql_connection = 'sqlite:////var/lib/quantum/quantum.sqlite'
+        EVS_DB_ENGINE = sa.create_engine(sql_connection, echo=True)
+        EVS_DB_BASE.metadata.create_all(EVS_DB_ENGINE)
+
+
+def get_session(autocommit=True, expire_on_commit=False):
+    global EVS_DB_ENGINE, EVS_DB_MAKER
+    assert EVS_DB_ENGINE
+    if not EVS_DB_MAKER:
+        EVS_DB_MAKER = orm.sessionmaker(bind=EVS_DB_ENGINE,
+                                        autocommit=autocommit,
+                                        expire_on_commit=expire_on_commit)
+    return EVS_DB_MAKER()
+
+
+def get_evs_context(context):
+    """Overrides the Quantum DB session with EVS DB session"""
+
+    evs_context = EVSContext.from_dict(context.to_dict())
+    evs_context.session = get_session()
+
+    return evs_context