List APIs: fix the stoken calculation for collections.

I'm not sure why it just wouldn't work with aggregate. I also couldn't get it
to work with annotate then aggregate or any other alternative.
This commit is contained in:
Tom Hacohen 2020-06-22 14:20:26 +03:00
parent 6117cac111
commit fcb58f0f4c

View File

@ -106,9 +106,15 @@ class BaseViewSet(viewsets.ModelViewSet):
return queryset, stoken_rev
def get_queryset_stoken(self, queryset):
aggr_fields = {x: Max(x) for x in self.stoken_id_fields}
aggr = queryset.aggregate(**aggr_fields)
maxid = max(map(lambda x: x or -1, aggr.values()))
aggr_field_names = ['max_{}'.format(i) for i, x in enumerate(self.stoken_id_fields)]
aggr_fields = {name: Max(field) for name, field in zip(aggr_field_names, self.stoken_id_fields)}
aggr = queryset.annotate(**aggr_fields).values(*aggr_field_names)
# FIXME: we are doing it in python instead of SQL because I just couldn't get aggregate to work over the
# annotated values. This should probably be fixed as it could be quite slow
maxid = -1
for row in aggr:
rowmaxid = max(map(lambda x: x or -1, row.values()))
maxid = max(maxid, rowmaxid)
new_stoken = (maxid >= 0) and Stoken.objects.get(id=maxid).uid
return queryset, new_stoken