Mark content_ids as deferred and drop 65535 conditional for subquerying

Author: Andrew Cheng

pulpcore/app/models/repository.py

@@ -997,11 +997,7 @@ def get_content(self, content_qs=None):
         if content_qs is None:
             content_qs = Content.objects
 
-        content_ids = self.content_ids
-        if len(content_ids) >= 65535:
-            # Workaround for PostgreSQL's limit on the number of parameters in a query
-            content_ids = self.content_ids_subquery()
-        return content_qs.filter(pk__in=content_ids)
+        return content_qs.filter(pk__in=self.content_ids_subquery())
 
     def content_ids_subquery(self):
         """

pulpcore/app/viewsets/base.py

@@ -157,7 +157,7 @@ def get_resource_model(uri):
         return match.func.cls.queryset.model
 
     @staticmethod
-    def get_resource(uri, model=None):
+    def get_resource(uri, model=None, deferred_fields=None):
         """
         Resolve a resource URI/PRN to an instance of the resource.
 
@@ -168,6 +168,9 @@ def get_resource(uri, model=None):
             uri (str): A resource URI/PRN.
             model (django.models.Model): A model class. If not provided, the method automatically
                 determines the used model from the resource URI/PRN.
+            deferred_fields (iterable): Optional field names to defer when loading the resource, so
+                large columns are not fetched from the database. Field names that do not exist on
+                the resolved model are ignored.
 
         Returns:
             django.models.Model: The resource fetched from the DB.
@@ -207,7 +210,13 @@ def get_resource(uri, model=None):
                     kwargs[key] = value
 
         try:
-            return model.objects.get(**kwargs)
+            manager = model.objects
+            if deferred_fields:
+                model_fields = {field.name for field in model._meta.concrete_fields}
+                to_defer = [name for name in deferred_fields if name in model_fields]
+                if to_defer:
+                    manager = manager.defer(*to_defer)
+            return manager.get(**kwargs)
         except model.MultipleObjectsReturned:
             raise DRFValidationError(
                 detail=_("URI {u} matches more than one {m}.").format(

pulpcore/app/viewsets/custom_filters.py

@@ -145,9 +145,12 @@ def get_repository_version(value):
                 detail=_("No value supplied for repository version filter")
             )
 
-        object = NamedModelViewSet.get_resource(value)
+        # content_ids is only consumed as a database-side subquery (see
+        # RepositoryVersion.content_ids_subquery), so defer the potentially huge array column here
+        # to keep it from being loaded into Python when resolving the version.
+        object = NamedModelViewSet.get_resource(value, deferred_fields=("content_ids",))
         if isinstance(object, Repository):
-            object = object.latest_version()
+            object = object.versions.complete().defer("content_ids").last()
         if not isinstance(object, RepositoryVersion):
             raise serializers.ValidationError(
                 detail=_("URI {u} not found for {m}.").format(u=value, m="repositoryversion")