optimize file recursive rights

core/models.py

@@ -1057,20 +1057,38 @@ class SithFile(models.Model):
         if self.is_file and (self.file is None or self.file == ""):
             raise ValidationError(_("You must provide a file"))
 
-    def apply_rights_recursively(self, *, only_folders=False):
-        children = self.children.all()
+    def apply_rights_recursively(self, *, only_folders: bool = False) -> None:
+        """Apply the rights of this file to all children recursively.
+
+        Args:
+            only_folders: If True, only apply the rights to SithFiles that are folders.
+        """
+        file_ids = []
+        explored_ids = [self.id]
+        while len(explored_ids) > 0:  # find all children recursively
+            file_ids.extend(explored_ids)
+            next_level = SithFile.objects.filter(parent_id__in=explored_ids)
             if only_folders:
-            children = children.filter(is_folder=True)
-        for c in children:
-            c.copy_rights()
-            c.apply_rights_recursively(only_folders=only_folders)
+                next_level = next_level.filter(is_folder=True)
+            explored_ids = list(next_level.values_list("id", flat=True))
+        for through in (SithFile.view_groups.through, SithFile.edit_groups.through):
+            # force evaluation. Without this, the iterator yields nothing
+            groups = list(
+                through.objects.filter(sithfile_id=self.id).values_list(
+                    "group_id", flat=True
+                )
+            )
+            # delete previous rights
+            through.objects.filter(sithfile_id__in=file_ids).delete()
+            through.objects.bulk_create(  # create new rights
+                [through(sithfile_id=f, group_id=g) for f in file_ids for g in groups]
+            )
 
     def copy_rights(self):
         """Copy, if possible, the rights of the parent folder."""
         if self.parent is not None:
             self.edit_groups.set(self.parent.edit_groups.all())
             self.view_groups.set(self.parent.view_groups.all())
-            self.save()
 
     def move_to(self, parent):
         """Move a file to a new parent.

core/tests/test_family.py

@@ -22,7 +22,7 @@ class TestFetchFamilyApi(TestCase):
         #           <- user5
 
         cls.main_user = baker.make(User)
-        cls.users = baker.make(User, _quantity=17)
+        cls.users = baker.make(User, _quantity=17, _bulk_create=True)
         cls.main_user.godfathers.add(*cls.users[0:3])
         cls.main_user.godchildren.add(*cls.users[3:6])
         cls.users[1].godfathers.add(cls.users[6])

core/tests/test_files.py

@@ -1,4 +1,5 @@
 from io import BytesIO
+from itertools import cycle
 from typing import Callable
 from uuid import uuid4
 
@@ -10,9 +11,10 @@ from django.urls import reverse
 from model_bakery import baker
 from model_bakery.recipe import Recipe, foreign_key
 from PIL import Image
+from pytest_django.asserts import assertNumQueries
 
 from core.baker_recipes import board_user, subscriber_user
-from core.models import SithFile, User
+from core.models import Group, SithFile, User
 
 
 @pytest.mark.django_db
@@ -184,3 +186,36 @@ class TestUserProfilePicture:
         assert user.profile_pict is not None
         # uploaded images should be converted to WEBP
         assert Image.open(user.profile_pict.file).format == "WEBP"
+
+
+@pytest.mark.django_db
+def test_apply_rights_recursively():
+    """Test that the apply_rights_recursively method works as intended."""
+    files = [baker.make(SithFile)]
+    files.extend(baker.make(SithFile, _quantity=3, parent=files[0], _bulk_create=True))
+    files.extend(
+        baker.make(SithFile, _quantity=3, parent=iter(files[1:4]), _bulk_create=True)
+    )
+    files.extend(
+        baker.make(SithFile, _quantity=6, parent=cycle(files[4:7]), _bulk_create=True)
+    )
+
+    groups = list(baker.make(Group, _quantity=7))
+    files[0].view_groups.set(groups[:3])
+    files[0].edit_groups.set(groups[2:6])
+
+    # those groups should be erased after the function call
+    files[1].view_groups.set(groups[6:])
+
+    with assertNumQueries(10):
+        # 1 query for each level of depth (here 4)
+        # 1 query to get the view_groups of the first file
+        # 1 query to delete the previous view_groups
+        # 1 query apply the new view_groups
+        # same 3 queries for the edit_groups
+        files[0].apply_rights_recursively()
+    for file in SithFile.objects.filter(pk__in=[f.pk for f in files]).prefetch_related(
+        "view_groups", "edit_groups"
+    ):
+        assert set(file.view_groups.all()) == set(groups[:3])
+        assert set(file.edit_groups.all()) == set(groups[2:6])