fix: iterate over prefetched taxonomyorgs instead of filtering

to avoid re-querying.

Changes TaxonomyOrg.get_organizations to return the "all orgs" flag too,
which makes it useful in the rules.

openedx/core/djangoapps/content_tagging/models/base.py

@@ -67,19 +67,24 @@ def get_relationships(
 
     @classmethod
     def get_organizations(
-        cls, taxonomy: Taxonomy, rel_type: RelType
-    ) -> list[Organization]:
+        cls, taxonomy: Taxonomy, rel_type=RelType.OWNER,
+    ) -> tuple[bool, list[Organization]]:
         """
-        Returns the list of Organizations which have the given relationship to the taxonomy.
+        Returns a tuple containing:
+        * bool: flag indicating whether "all organizations" have the given relationship to the taxonomy
+        * orgs: list of Organizations which have the given relationship to the taxonomy
         """
-        rels = cls.objects.filter(
-            taxonomy=taxonomy,
-            rel_type=rel_type,
-        )
-        # A relationship with org=None means all Organizations
-        if rels.filter(org=None).exists():
-            return list(Organization.objects.all())
-        return [rel.org for rel in rels]
+        is_all_org = False
+        orgs = []
+        # Iterate over the taxonomyorgs instead of filtering to take advantage of prefetched data.
+        for taxonomy_org in taxonomy.taxonomyorg_set.all():
+            if taxonomy_org.rel_type == rel_type:
+                if taxonomy_org.org is None:
+                    is_all_org = True
+                else:
+                    orgs.append(taxonomy_org.org)
+
+        return (is_all_org, orgs)
 
 
 class ContentObjectTag(ObjectTag):

openedx/core/djangoapps/content_tagging/rest_api/v1/serializers.py

@@ -80,7 +80,11 @@ def get_all_orgs(self, obj) -> bool:
         """
         Return True if the taxonomy is associated with all orgs.
         """
-        return obj.taxonomyorg_set.filter(org__isnull=True).exists()
+        is_all_orgs = False
+        for taxonomy_org in obj.taxonomyorg_set.all():
+            if taxonomy_org.org_id is None:
+                return True
+        return False
 
     class Meta:
         model = TaxonomySerializer.Meta.model

openedx/core/djangoapps/content_tagging/rest_api/v1/tests/test_views.py

@@ -497,7 +497,7 @@ def test_list_taxonomy_query_count(self):
         url = TAXONOMY_ORG_LIST_URL + f'?org={self.orgA.short_name}&enabled=true'
 
         self.client.force_authenticate(user=self.staff)
-        with self.assertNumQueries(15):  # TODO Why so many queries?
+        with self.assertNumQueries(11):
             response = self.client.get(url)
 
         assert response.status_code == 200

openedx/core/djangoapps/content_tagging/rules.py

@@ -141,21 +141,12 @@ def can_view_taxonomy(user: UserType, taxonomy: oel_tagging.Taxonomy) -> bool:
     if oel_tagging.is_taxonomy_admin(user):
         return True
 
-    is_all_org = TaxonomyOrg.objects.filter(
-        taxonomy=taxonomy,
-        org=None,
-        rel_type=TaxonomyOrg.RelType.OWNER,
-    ).exists()
+    is_all_org, taxonomy_orgs = TaxonomyOrg.get_organizations(taxonomy)
 
     # Enabled all-org taxonomies can be viewed by any registred user
     if is_all_org:
         return taxonomy.enabled
 
-    taxonomy_orgs = TaxonomyOrg.get_organizations(
-        taxonomy=taxonomy,
-        rel_type=TaxonomyOrg.RelType.OWNER,
-    )
-
     # Org-level staff can view any taxonomy that is associated with one of their orgs.
     if is_org_admin(user, taxonomy_orgs):
         return True
@@ -191,21 +182,12 @@ def can_change_taxonomy(user: UserType, taxonomy: oel_tagging.Taxonomy) -> bool:
     if oel_tagging.is_taxonomy_admin(user):
         return True
 
-    is_all_org = TaxonomyOrg.objects.filter(
-        taxonomy=taxonomy,
-        org=None,
-        rel_type=TaxonomyOrg.RelType.OWNER,
-    ).exists()
+    is_all_org, taxonomy_orgs = TaxonomyOrg.get_organizations(taxonomy)
 
     # Only taxonomy admins can edit all org taxonomies
     if is_all_org:
         return False
 
-    taxonomy_orgs = TaxonomyOrg.get_organizations(
-        taxonomy=taxonomy,
-        rel_type=TaxonomyOrg.RelType.OWNER,
-    )
-
     # Org-level staff can edit any taxonomy that is associated with one of their orgs.
     if is_org_admin(user, taxonomy_orgs):
         return True