Ensure the statistics are sorted

Sort the statistics by the period start date before
returning them, and restore the test that verifies
this behavior.

bug 1151345

Change-Id: I4f05ea049b7609cea9dab947738b7aabf3f062ef
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>

ceilometer/storage/impl_mongodb.py

@@ -20,6 +20,7 @@
 
 import copy
 import datetime
+import operator
 import re
 import urlparse
 
@@ -519,7 +520,8 @@ def get_meter_statistics(self, event_filter, period=None):
             query=q,
         )
 
-        return [r['value'] for r in results['results']]
+        return sorted((r['value'] for r in results['results']),
+                      key=operator.itemgetter('period_start'))
 
     def get_volume_sum(self, event_filter):
         """Return the sum of the volume field for the events

tests/storage/base.py

@@ -804,9 +804,6 @@ def test_by_user_period(self):
         self.assertEqual(set(r['period_end'] for r in results),
                          set([datetime.datetime(2012, 9, 25, 12, 28),
                               datetime.datetime(2012, 9, 25, 14, 28)]))
-        '''
-        # FXIME(llu) Temporary comment out to pass Jenkins unittest.
-        # Will resume this after bug #1151345 is fixed.
         r = results[0]
         self.assertEqual(r['period_start'],
                          datetime.datetime(2012, 9, 25, 10, 28))
@@ -824,7 +821,6 @@ def test_by_user_period(self):
                          datetime.datetime(2012, 9, 25, 10, 30))
         self.assertEqual(r['duration_end'],
                          datetime.datetime(2012, 9, 25, 11, 31))
-        '''
 
     def test_by_project(self):
         f = storage.EventFilter(