Implement DataDriver for sqlalchemy storage backend

Partially Implements blueprint sql-storage-driver

Change-Id: I84b67ac50e88645ef69a42860021d72c86a6d018

marconi/queues/storage/sqlalchemy/driver.py

@@ -0,0 +1,67 @@
+# Copyright (c) 2013 Red Hat, Inc.
+#
+# 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.
+
+import sqlalchemy as sa
+
+from oslo.config import cfg
+
+from marconi.common import decorators
+from marconi.queues import storage
+from marconi.queues.storage.sqlalchemy import tables
+
+
+_SQLALCHEMY_OPTIONS = [
+    cfg.StrOpt('database', default=':memory:',
+               help='Sqlalchemy database to use.')
+]
+
+_SQLALCHEMY_GROUP = 'drivers:storage:sqlalchemy'
+
+
+class DataDriver(storage.DataDriverBase):
+
+    def __init__(self, conf, cache):
+        super(DataDriver, self).__init__(conf, cache)
+
+        self.conf.register_opts(_SQLALCHEMY_OPTIONS, group=_SQLALCHEMY_GROUP)
+        self.sqlalchemy_conf = self.conf[_SQLALCHEMY_GROUP]
+
+        self.__path = self.sqlalchemy_conf.database
+
+    @decorators.lazy_property(write=False)
+    def engine(self, *args, **kwargs):
+        engine = sa.create_engine(*args, **kwargs)
+        tables.metadata.create_all(engine, checkfirst=True)
+        return engine
+
+    @decorators.lazy_property(write=False)
+    def connection(self):
+        return self.engine.connect()
+
+    def close_connection(self):
+        self.connection.close()
+
+    @decorators.lazy_property(write=False)
+    def queue_controller(self):
+        return None
+
+    @decorators.lazy_property(write=False)
+    def message_controller(self):
+        return None
+
+    @decorators.lazy_property(write=False)
+    def claim_controller(self):
+        return None