Merge "Add get_counts() to InstanceMappingList"

nova/objects/instance_mapping.py

@@ -17,6 +17,7 @@ from oslo_utils import versionutils
 import six
 from sqlalchemy.orm import joinedload
 from sqlalchemy.sql import false
+from sqlalchemy.sql import func
 from sqlalchemy.sql import or_
 
 from nova import context as nova_context
@@ -294,7 +295,8 @@ class InstanceMappingList(base.ObjectListBase, base.NovaObject):
     # Version 1.0: Initial version
     # Version 1.1: Added get_by_cell_id method.
     # Version 1.2: Added get_by_instance_uuids method
-    VERSION = '1.2'
+    # Version 1.3: Added get_counts()
+    VERSION = '1.3'
 
     fields = {
         'objects': fields.ListOfObjectsField('InstanceMapping'),
@@ -391,3 +393,42 @@ class InstanceMappingList(base.ObjectListBase, base.NovaObject):
             context, cell_uuid, project_id, limit)
         return base.obj_make_list(context, cls(), objects.InstanceMapping,
                 db_mappings)
+
+    @staticmethod
+    @db_api.api_context_manager.reader
+    def _get_counts_in_db(context, project_id, user_id=None):
+        project_query = context.session.query(
+            func.count(api_models.InstanceMapping.id)).\
+            filter_by(queued_for_delete=False).\
+            filter_by(project_id=project_id)
+        project_result = project_query.scalar()
+        counts = {'project': {'instances': project_result}}
+        if user_id:
+            user_result = project_query.filter_by(user_id=user_id).scalar()
+            counts['user'] = {'instances': user_result}
+        return counts
+
+    @base.remotable_classmethod
+    def get_counts(cls, context, project_id, user_id=None):
+        """Get the counts of InstanceMapping objects in the database.
+
+        The count is used to represent the count of instances for the purpose
+        of counting quota usage. Instances that are queued_for_deleted=True are
+        not included in the count (deleted and SOFT_DELETED instances).
+        Instances that are queued_for_deleted=None are not included in the
+        count because we are not certain about whether or not they are deleted.
+        When counting quota usage, we will fall back on the legacy counting
+        method and count instances, cores, and ram from cell databases if any
+        unmigrated instance mappings (user_id=None or queued_for_delete=None)
+        are detected, to avoid using a potentially inaccurate count.
+
+        :param context: The request context for database access
+        :param project_id: The project_id to count across
+        :param user_id: The user_id to count across
+        :returns: A dict containing the project-scoped counts and user-scoped
+                  counts if user_id is specified. For example:
+
+                    {'project': {'instances': <count across project>},
+                     'user': {'instances': <count across user>}}
+        """
+        return cls._get_counts_in_db(context, project_id, user_id=user_id)

nova/tests/functional/db/test_instance_mapping.py

@@ -577,3 +577,31 @@ class InstanceMappingListTestCase(test.NoDBTestCase):
                                                    cm.uuid,
                                                    None))
         self.assertEqual(2, len(ims))
+
+    def test_get_counts(self):
+        create_mapping(project_id='fake-project', user_id='fake-user',
+                       queued_for_delete=False)
+        # mapping with another user
+        create_mapping(project_id='fake-project', user_id='other-user',
+                       queued_for_delete=False)
+        # mapping in another project
+        create_mapping(project_id='other-project', user_id='fake-user',
+                       queued_for_delete=False)
+        # queued_for_delete=True, should not be counted
+        create_mapping(project_id='fake-project', user_id='fake-user',
+                       queued_for_delete=True)
+        # queued_for_delete=None (not yet migrated), should not be counted
+        create_mapping(project_id='fake-project', user_id='fake-user',
+                       queued_for_delete=None)
+
+        # Count only across a project
+        counts = instance_mapping.InstanceMappingList.get_counts(
+            self.context, 'fake-project')
+        self.assertEqual(2, counts['project']['instances'])
+        self.assertNotIn('user', counts)
+
+        # Count across a project and a user
+        counts = instance_mapping.InstanceMappingList.get_counts(
+            self.context, 'fake-project', user_id='fake-user')
+        self.assertEqual(2, counts['project']['instances'])
+        self.assertEqual(1, counts['user']['instances'])

nova/tests/unit/objects/test_objects.py

@@ -1086,7 +1086,7 @@ object_data = {
     'InstanceInfoCache': '1.5-cd8b96fefe0fc8d4d337243ba0bf0e1e',
     'InstanceList': '2.4-d2c5723da8c1d08e07cb00160edfd292',
     'InstanceMapping': '1.2-3bd375e65c8eb9c45498d2f87b882e03',
-    'InstanceMappingList': '1.2-ee638619aa3d8a82a59c0c83bfa64d78',
+    'InstanceMappingList': '1.3-d34b6ebb076d542ae0f8b440534118da',
     'InstanceNUMACell': '1.4-7c1eb9a198dee076b4de0840e45f4f55',
     'InstanceNUMATopology': '1.3-ec0030cb0402a49c96da7051c037082a',
     'InstancePCIRequest': '1.3-f6d324f1c337fad4f34892ed5f484c9a',