Fixed #35408 -- Optimized post-migrate permission creation.

co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

django/contrib/auth/management/__init__.py

@@ -46,6 +46,13 @@ def create_permissions(
     if not app_config.models_module:
         return
 
+    try:
+        Permission = apps.get_model("auth", "Permission")
+    except LookupError:
+        return
+    if not router.allow_migrate_model(using, Permission):
+        return
+
     # Ensure that contenttypes are created for this app. Needed if
     # 'django.contrib.auth' is in INSTALLED_APPS before
     # 'django.contrib.contenttypes'.
@@ -62,36 +69,33 @@ def create_permissions(
     try:
         app_config = apps.get_app_config(app_label)
         ContentType = apps.get_model("contenttypes", "ContentType")
-        Permission = apps.get_model("auth", "Permission")
     except LookupError:
         return
 
     if not router.allow_migrate_model(using, Permission):
         return
 
+    models = list(app_config.get_models())
+    # Grab all the content types from the current database.
+    ctypes = ContentType.objects.db_manager(using).get_for_models(
+        *models, for_concrete_models=False
+    )
     # This will hold the permissions we're looking for as
     # (content_type, (codename, name))
     searched_perms = []
-    # The codenames and ctypes that should exist.
-    ctypes = set()
-    for klass in app_config.get_models():
-        # Force looking up the content types in the current database
-        # before creating foreign keys to them.
-        ctype = ContentType.objects.db_manager(using).get_for_model(
-            klass, for_concrete_model=False
+    for model in models:
+        ctype = ctypes[model]
+        searched_perms.extend(
+            [(ctype, perm) for perm in _get_all_permissions(model._meta)]
         )
 
-        ctypes.add(ctype)
-        for perm in _get_all_permissions(klass._meta):
-            searched_perms.append((ctype, perm))
-
     # Find all the Permissions that have a content_type for a model we're
     # looking for.  We don't need to check for codenames since we already have
     # a list of the ones we're going to create.
     all_perms = set(
         Permission.objects.using(using)
         .filter(
-            content_type__in=ctypes,
+            content_type__in=set(ctypes.values()),
         )
         .values_list("content_type", "codename")
     )

tests/auth_tests/test_management.py

@@ -1528,7 +1528,7 @@ class CreatePermissionsMultipleDatabasesTests(TestCase):
 
     def test_set_permissions_fk_to_using_parameter(self):
         Permission.objects.using("other").delete()
-        with self.assertNumQueries(6, using="other") as captured_queries:
+        with self.assertNumQueries(4, using="other") as captured_queries:
             create_permissions(apps.get_app_config("auth"), verbosity=0, using="other")
         self.assertIn("INSERT INTO", captured_queries[-1]["sql"].upper())
         self.assertGreater(Permission.objects.using("other").count(), 0)

tests/contenttypes_tests/test_models.py

@@ -48,7 +48,7 @@ def test_lookup_cache(self):
 
     def test_get_for_models_creation(self):
         ContentType.objects.all().delete()
-        with self.assertNumQueries(4):
+        with self.assertNumQueries(2):
             cts = ContentType.objects.get_for_models(
                 ContentType, FooWithUrl, ProxyModel, ConcreteModel
             )