fetch_things2: Assert that a sort order is provided.

Otherwise you end up in a bizarro infinite loop.

r2/r2/lib/count.py

@@ -22,6 +22,7 @@
 
 from r2.models import Link, Subreddit
 from r2.lib import utils
+from r2.lib.db.operators import desc
 from pylons import g
 
 count_period = g.rising_period
@@ -40,7 +41,7 @@ def get_link_counts(period = count_period):
     return dict((l._fullname, (0, l.sr_id)) for l in links)
 
 def get_sr_counts():
-    srs = utils.fetch_things2(Subreddit._query())
+    srs = utils.fetch_things2(Subreddit._query(sort=desc("_date")))
 
     return dict((sr._fullname, sr._ups) for sr in srs)
 

r2/r2/lib/utils/utils.py

@@ -770,6 +770,9 @@ def fetch_things2(query, chunk_size = 100, batch_fn = None, chunks = False):
     """Incrementally run query with a limit of chunk_size until there are
     no results left. batch_fn transforms the results for each chunk
     before returning."""
+
+    assert query._sort, "you must specify the sort order in your query!"
+
     orig_rules = deepcopy(query._rules)
     query._limit = chunk_size
     items = list(query)