Added filter operators

In this changeset, I refactored the DB filter system to support
comparison operators using a django-like syntax.
A filter can take 2 forms:

- "<FIELDNAME>" which is a syntactic sugar for "<FIELDNAME>__eq"
- "<FIELDNAME>__<OPERATOR>" where <OPERATOR> is the comparison operator
  to be used.

Here is the list of the supported operators:

- 'eq' (==)
- 'neq' (!=)
- 'gt' (>)
- 'gte' (>=)
- 'lt' (<)
- 'lte' (<=)
- 'in' (in)
- 'notin' (not in)

Change-Id: I53a61d50a3253342a40f0ff87cb5612ed57a3bd1

watcher/tests/db/test_audit.py

@@ -47,10 +47,12 @@ class TestDbAuditFilters(base.DbTestCase):
                 audit_template_id=self.audit_template.id, id=1, uuid=None)
         with freezegun.freeze_time(self.FAKE_OLD_DATE):
             self.audit2 = utils.create_test_audit(
-                audit_template_id=self.audit_template.id, id=2, uuid=None)
+                audit_template_id=self.audit_template.id, id=2, uuid=None,
+                state=audit_objects.State.FAILED)
         with freezegun.freeze_time(self.FAKE_OLDER_DATE):
             self.audit3 = utils.create_test_audit(
-                audit_template_id=self.audit_template.id, id=3, uuid=None)
+                audit_template_id=self.audit_template.id, id=3, uuid=None,
+                state=audit_objects.State.CANCELLED)
 
     def _soft_delete_audits(self):
         with freezegun.freeze_time(self.FAKE_TODAY):
@@ -225,6 +227,26 @@ class TestDbAuditFilters(base.DbTestCase):
             [self.audit1['id'], self.audit2['id']],
             [r.id for r in res])
 
+    def test_get_audit_list_filter_state_in(self):
+        res = self.dbapi.get_audit_list(
+            self.context,
+            filters={'state__in': (audit_objects.State.FAILED,
+                                   audit_objects.State.CANCELLED)})
+
+        self.assertEqual(
+            [self.audit2['id'], self.audit3['id']],
+            [r.id for r in res])
+
+    def test_get_audit_list_filter_state_notin(self):
+        res = self.dbapi.get_audit_list(
+            self.context,
+            filters={'state__notin': (audit_objects.State.FAILED,
+                                      audit_objects.State.CANCELLED)})
+
+        self.assertEqual(
+            [self.audit1['id']],
+            [r.id for r in res])
+
 
 class DbAuditTestCase(base.DbTestCase):