get_relations() called multiple times on pre-identified related resources

[whatisgalen]

At this line:

if len(instanceids) > 0:
            related_resources = se.search(index=RESOURCES_INDEX, id=list(instanceids))
            if related_resources:
                for resource in related_resources["docs"]:
                    relations = get_relations(
                        resourceinstanceid=resource["_id"],
                        start=0,
                        limit=0,
                    )
                    if resource["found"]:
                        resource["_source"]["total_relations"] = relations["total"]

                        for descriptor_type in ("displaydescription", "displayname"):
                            descriptor = get_localized_descriptor(
                                resource, descriptor_type
                            )
                            if descriptor:
                                resource["_source"][descriptor_type] = descriptor
                            else:
                                resource["_source"][descriptor_type] = _("Undefined")

                        ret["related_resources"].append(resource["_source"])

the get_relations method is called on a related resource instance solely to provide a "total" number and is not used again. The overhead of this method:

def get_relations(
            resourceinstanceid, start, limit, resourceinstance_graphid=None
        ):
            final_query = Q(resourceinstanceidfrom_id=resourceinstanceid) | Q(
                resourceinstanceidto_id=resourceinstanceid
            )

            if resourceinstance_graphid:
                to_graph_id_filter = Q(
                    resourceinstancefrom_graphid_id=str(self.graph_id)
                ) & Q(resourceinstanceto_graphid_id=resourceinstance_graphid)
                from_graph_id_filter = Q(
                    resourceinstancefrom_graphid_id=resourceinstance_graphid
                ) & Q(resourceinstanceto_graphid_id=str(self.graph_id))
                final_query = final_query & (to_graph_id_filter | from_graph_id_filter)

            relations = {
                "total": models.ResourceXResource.objects.filter(final_query).count(),
                "relations": models.ResourceXResource.objects.filter(final_query)[
                    start:limit
                ],
            }

            return relations  # resourceinstance_graphid = "00000000-886a-374a-94a5-984f10715e3a"

...implies an ORM query every time.

This isn't actually needed. We can likely get this total figure elsewhere, but besides that this property total_relations doesn't appear to be used, also we already called this method earlier anyway:

resource_relations = get_relations(
            resourceinstanceid=self.resourceinstanceid,
            start=start,
            limit=limit,
            resourceinstance_graphid=resourceinstance_graphid,
        )

[whatisgalen]

completed by #11460