Merge pull request #9 from jezdez/issue_9

_get_user_cached_perms is doing a dependent sub-query

README

@@ -52,6 +52,12 @@ html version using the setup.py::
 Changelog:
 ==========
 
+0.7 (2013-07-03):
+-----------------
+
+* No longer doing dependent sub-queries. It will be faster to do two small
+  queries instead of one with a dependent sub-query in the general case.
+
 0.6 (2013-06-13):
 -----------------
 

authority/permissions.py

@@ -48,8 +48,12 @@ def _get_user_cached_perms(self):
         """
         if not self.user:
             return {}, {}
+        group_pks = set(self.user.groups.values_list(
+            'pk',
+            flat=True,
+        ))
         perms = Permission.objects.filter(
-            Q(user__pk=self.user.pk) | Q(group__in=self.user.groups.all()),
+            Q(user__pk=self.user.pk) | Q(group__pk__in=group_pks),
         )
         user_permissions = {}
         group_permissions = {}

authority/tests.py

@@ -1,6 +1,5 @@
 from django import VERSION
 from django.conf import settings
-from django.contrib import auth
 from django.contrib.auth.models import Permission as DjangoPermission
 from django.contrib.auth.models import Group
 from django.db.models import Q
@@ -77,7 +76,7 @@ def test_delete(self):
         # test
         self.assertFalse(self.check.delete_user())
         self.assertTrue(self.check.delete_user(self.user))
-        
+
 
 class AssignBehaviourTest(TestCase):
     """
@@ -236,7 +235,7 @@ def test_has_user_perms(self):
         # Regardless of how many times has_user_perms is called, the number of
         # queries is the same.
         # Content type and permissions (2 queries)
-        with self.assertNumQueries(2):
+        with self.assertNumQueries(3):
             for _ in range(5):
                 # Need to assert it so the query actually gets executed.
                 assert not self.user_check.has_user_perms(
@@ -259,7 +258,7 @@ def test_has_user_perms_check_group(self):
         # Regardless of the number groups permissions, it should only take one
         # query to check both users and groups.
         # Content type and permissions (2 queries)
-        with self.assertNumQueries(2):
+        with self.assertNumQueries(3):
             self.user_check.has_user_perms(
                 'foo',
                 self.user,
@@ -273,7 +272,7 @@ def test_invalidate_user_permissions_cache(self):
         # For each time invalidate_permissions_cache gets called, you
         # will need to do one query to get content type and one to get
         # the permissions.
-        with self.assertNumQueries(4):
+        with self.assertNumQueries(6):
             for _ in range(5):
                 assert not self.user_check.has_user_perms(
                     'foo',
@@ -335,7 +334,7 @@ def test_has_user_perms_check_group_multiple(self):
         # gets created.
 
         # Check the number of queries.
-        with self.assertNumQueries(1):
+        with self.assertNumQueries(2):
             assert self.user_check.has_user_perms('foo', self.user, True, True)
 
         # Create a second group.
@@ -354,7 +353,7 @@ def test_has_user_perms_check_group_multiple(self):
         self.user_check.invalidate_permissions_cache()
 
         # Make sure it is the same number of queries.
-        with self.assertNumQueries(1):
+        with self.assertNumQueries(2):
             assert self.user_check.has_user_perms('foo', self.user, True, True)