[#1038] Improve performance of viewing hierarchy, avoiding groups as …

…SQLAlchemy objects.

ckan/model/group.py

@@ -197,15 +197,16 @@ def get_children_group_hierarchy(self, type='group'):
         hierarchy. The ordering is such that children always come after their
         parent.
 
-        :rtype: a list of tuples, each one a Group and the ID of its parent
-        group.
+        :rtype: a list of tuples, each one a Group ID, name and title and then
+        the ID of its parent group.
 
-        e.g. >>> dept-health.get_children_group_hierarchy()
-             [(<Group nhs>, u'8a163ba7-5146-4325-90c8-fe53b25e28d0'),
-              (<Group wirral-ccg>, u'06e6dbf5-d801-40a1-9dc0-6785340b2ab4'),
-              (<Group newport-ccg>, u'd2e25b41-720c-4ba7-bc8f-bb34b185b3dd')]
+        e.g. 
+        >>> dept-health.get_children_group_hierarchy()
+        [(u'8ac0...', u'national-health-service', u'National Health Service', u'e041...'), 
+         (u'b468...', u'nhs-wirral-ccg', u'NHS Wirral CCG', u'8ac0...')]
         '''
-        results = meta.Session.query(Group, 'parent_id').\
+        results = meta.Session.query(Group.id, Group.name, Group.title,
+                                     'parent_id').\
             from_statement(HIERARCHY_DOWNWARDS_CTE).\
             params(id=self.id, type=type).all()
         return results
@@ -242,7 +243,8 @@ def groups_allowed_to_be_its_parent(self, type='group'):
 
         '''
         all_groups = self.all(group_type=type)
-        excluded_groups = set(group.name for group, id_ in
+        excluded_groups = set(group_name
+                              for group_id, group_name, group_title, parent in
                               self.get_children_group_hierarchy(type=type))
         excluded_groups.add(self.name)
         return [group for group in all_groups
@@ -398,7 +400,7 @@ def __repr__(self):
     WHERE m.table_id = c.group_id AND m.table_name = 'group'
           AND m.state = 'active'
 )
-SELECT G.*, child.depth, child.table_id as parent_id FROM child
+SELECT G.id, G.name, G.title, child.depth, child.table_id as parent_id FROM child
     INNER JOIN public.group G ON G.id = child.group_id
     WHERE G.type = :type AND G.state='active'
     ORDER BY child.depth ASC;"""

ckan/tests/models/test_group.py

@@ -93,7 +93,7 @@ def _search_results(self, query, is_org=False):
         return set([group.name for group in results])
 
 name_set_from_dicts = lambda groups: set([group['name'] for group in groups])
-name_set_from_group_tuple = lambda tuples: set([t[0].name for t in tuples])
+name_set_from_group_tuple = lambda tuples: set([t[1] for t in tuples])
 name_set_from_groups = lambda groups: set([group.name for group in groups])
 names_from_groups = lambda groups: [group.name for group in groups]
 
@@ -122,8 +122,8 @@ def test_get_children_group_hierarchy__from_top_2(self):
         # the first group must be NHS or Food Standards Agency - i.e. on the
         # first level down
         nhs = groups[0]
-        assert_in(nhs[0].name, ('national-health-service', 'food-standards-agency'))
-        assert_equal(model.Group.get(nhs[1]).name, 'department-of-health')
+        assert_in(nhs[1], ('national-health-service', 'food-standards-agency'))
+        assert_equal(model.Group.get(nhs[3]).name, 'department-of-health')
 
     def test_get_children_group_hierarchy__from_top(self):
         assert_equal(name_set_from_group_tuple(model.Group.by_name(u'department-of-health').\