Better usage of cache for groups and clubs related operations (#634)

* Better usage of cache for group retrieval

* Cache clearing on object deletion or update

* replace signals by save and delete override

* add is_anonymous check in is_owned_by

Add in many is_owned_by(self, user) methods that user is not anonymous. Since many of those functions do db queries, this should reduce a little bit the load of the db.

* Stricter usage of User.is_in_group

Constrain the parameters that can be passed to the function to make sure only a str or an int can be used. Also force to explicitly specify if the group id or the group name is used.

* write test and correct bugs

* remove forgotten populate commands

* Correct test

core/tests.py

@@ -15,13 +15,18 @@
 #
 
 import os
+from datetime import timedelta
 
+from django.core.cache import cache
 from django.test import Client, TestCase
 from django.urls import reverse
 from django.core.management import call_command
+from django.utils.timezone import now
 
-from core.models import User, Group, Page
+from club.models import Membership
+from core.models import User, Group, Page, AnonymousUser
 from core.markdown import markdown
+from sith import settings
 
 """
 to run these tests :
@@ -457,3 +462,150 @@ class FileHandlingTest(TestCase):
         )
         self.assertTrue(response.status_code == 200)
         self.assertTrue("ls</a>" in str(response.content))
+
+
+class UserIsInGroupTest(TestCase):
+    """
+    Test that the User.is_in_group() and AnonymousUser.is_in_group()
+    work as intended
+    """
+
+    @classmethod
+    def setUpTestData(cls):
+        from club.models import Club
+
+        cls.root_group = Group.objects.get(name="Root")
+        cls.public = Group.objects.get(name="Public")
+        cls.subscribers = Group.objects.get(name="Subscribers")
+        cls.old_subscribers = Group.objects.get(name="Old subscribers")
+        cls.accounting_admin = Group.objects.get(name="Accounting admin")
+        cls.com_admin = Group.objects.get(name="Communication admin")
+        cls.counter_admin = Group.objects.get(name="Counter admin")
+        cls.banned_alcohol = Group.objects.get(name="Banned from buying alcohol")
+        cls.banned_counters = Group.objects.get(name="Banned from counters")
+        cls.banned_subscription = Group.objects.get(name="Banned to subscribe")
+        cls.sas_admin = Group.objects.get(name="SAS admin")
+        cls.club = Club.objects.create(
+            name="Fake Club",
+            unix_name="fake-club",
+            address="Fake address",
+        )
+        cls.main_club = Club.objects.get(id=1)
+
+    def setUp(self) -> None:
+        self.toto = User.objects.create(
+            username="toto", first_name="a", last_name="b", email="a.b@toto.fr"
+        )
+        self.skia = User.objects.get(username="skia")
+
+    def assert_in_public_group(self, user):
+        self.assertTrue(user.is_in_group(pk=self.public.id))
+        self.assertTrue(user.is_in_group(name=self.public.name))
+
+    def assert_in_club_metagroups(self, user, club):
+        meta_groups_board = club.unix_name + settings.SITH_BOARD_SUFFIX
+        meta_groups_members = club.unix_name + settings.SITH_MEMBER_SUFFIX
+        self.assertFalse(user.is_in_group(name=meta_groups_board))
+        self.assertFalse(user.is_in_group(name=meta_groups_members))
+
+    def assert_only_in_public_group(self, user):
+        self.assert_in_public_group(user)
+        for group in (
+            self.root_group,
+            self.banned_counters,
+            self.accounting_admin,
+            self.sas_admin,
+            self.subscribers,
+            self.old_subscribers,
+        ):
+            self.assertFalse(user.is_in_group(pk=group.pk))
+            self.assertFalse(user.is_in_group(name=group.name))
+        meta_groups_board = self.club.unix_name + settings.SITH_BOARD_SUFFIX
+        meta_groups_members = self.club.unix_name + settings.SITH_MEMBER_SUFFIX
+        self.assertFalse(user.is_in_group(name=meta_groups_board))
+        self.assertFalse(user.is_in_group(name=meta_groups_members))
+
+    def test_anonymous_user(self):
+        """
+        Test that anonymous users are only in the public group
+        """
+        user = AnonymousUser()
+        self.assert_only_in_public_group(user)
+
+    def test_not_subscribed_user(self):
+        """
+        Test that users who never subscribed are only in the public group
+        """
+        self.assert_only_in_public_group(self.toto)
+
+    def test_wrong_parameter_fail(self):
+        """
+        Test that when neither the pk nor the name argument is given,
+        the function raises a ValueError
+        """
+        with self.assertRaises(ValueError):
+            self.toto.is_in_group()
+
+    def test_number_queries(self):
+        """
+        Test that the number of db queries is stable
+        and that less queries are made when making a new call
+        """
+        # make sure Skia is in at least one group
+        self.skia.groups.add(Group.objects.first().pk)
+        skia_groups = self.skia.groups.all()
+
+        group_in = skia_groups.first()
+        cache.clear()
+        # Test when the user is in the group
+        with self.assertNumQueries(2):
+            self.skia.is_in_group(pk=group_in.id)
+        with self.assertNumQueries(0):
+            self.skia.is_in_group(pk=group_in.id)
+
+        ids = skia_groups.values_list("pk", flat=True)
+        group_not_in = Group.objects.exclude(pk__in=ids).first()
+        cache.clear()
+        # Test when the user is not in the group
+        with self.assertNumQueries(2):
+            self.skia.is_in_group(pk=group_not_in.id)
+        with self.assertNumQueries(0):
+            self.skia.is_in_group(pk=group_not_in.id)
+
+    def test_cache_properly_cleared_membership(self):
+        """
+        Test that when the membership of a user end,
+        the cache is properly invalidated
+        """
+        membership = Membership.objects.create(
+            club=self.club, user=self.toto, end_date=None
+        )
+        meta_groups_members = self.club.unix_name + settings.SITH_MEMBER_SUFFIX
+        cache.clear()
+        self.assertTrue(self.toto.is_in_group(name=meta_groups_members))
+        self.assertEqual(
+            membership, cache.get(f"membership_{self.club.id}_{self.toto.id}")
+        )
+        membership.end_date = now() - timedelta(minutes=5)
+        membership.save()
+        cached_membership = cache.get(f"membership_{self.club.id}_{self.toto.id}")
+        self.assertEqual(cached_membership, "not_member")
+        self.assertFalse(self.toto.is_in_group(name=meta_groups_members))
+
+    def test_cache_properly_cleared_group(self):
+        """
+        Test that when a user is removed from a group,
+        the is_in_group_method return False when calling it again
+        """
+        self.toto.groups.add(self.com_admin.pk)
+        self.assertTrue(self.toto.is_in_group(pk=self.com_admin.pk))
+
+        self.toto.groups.remove(self.com_admin.pk)
+        self.assertFalse(self.toto.is_in_group(pk=self.com_admin.pk))
+
+    def test_not_existing_group(self):
+        """
+        Test that searching for a not existing group
+        returns False
+        """
+        self.assertFalse(self.skia.is_in_group(name="This doesn't exist"))