Optimize addon runs endpoint

documentcloud/addons/serializers.py

@@ -68,16 +68,19 @@ def __init__(self, *args, **kwargs):
 
     @extend_schema_field(serializers.BooleanField())
     def get_active(self, obj):
-
         if hasattr(obj, "active"):
             # pre calculate active for efficiency
             return obj.active
-
         request = self.context.get("request")
         if not request:
             return False
-
-        return request.user.active_addons.filter(pk=obj.pk).exists()
+        if not hasattr(self, "_active_pks"):
+            # build the pinned-addon PK set once per serializer (one query for the page)
+            # instead of an EXISTS per addon.
+            self._active_pks = set(
+                request.user.active_addons.values_list("pk", flat=True)
+            )
+        return obj.pk in self._active_pks
 
     class Meta:
         model = AddOn

documentcloud/addons/tests/test_views.py

@@ -351,6 +351,23 @@ def test_filter_domain_no_partial_host_match(self, client):
         assert response.status_code == status.HTTP_200_OK
         assert response.json()["results"] == []
 
+    def test_list_expand_query_count(self, client, django_assert_num_queries):
+        """
+        Expanding addon+event must not scale queries with the number of runs.
+        Query count stays flat (the run's addon/github_account/event are
+        select_related'd and get_active reads a cached PK set).
+        """
+        user = UserFactory(is_staff=True)
+        client.force_authenticate(user=user)
+        url = "/api/addon_runs/?expand=addon,event&per_page=100"
+
+        for expected_count in range(1, 11):
+            AddOnRunFactory(user=user, addon=AddOnFactory())
+            with django_assert_num_queries(7):
+                response = client.get(url)
+            assert response.status_code == status.HTTP_200_OK
+            assert len(response.json()["results"]) == expected_count
+
 
 @pytest.mark.django_db()
 class TestAddOnEventAPI:

documentcloud/addons/views.py

@@ -729,7 +729,7 @@ def get_queryset(self):
         """Only fetch add-on runs viewable to this user"""
         queryset = AddOnRun.objects.get_viewable(self.request.user)
         if is_expanded(self.request, "addon"):
-            queryset = queryset.select_related("addon")
+            queryset = queryset.select_related("addon", "addon__github_account")
         if is_expanded(self.request, "event"):
             queryset = queryset.select_related("event")
         return queryset