support ISO 8601 micro-second precision

Bug 1134802

Change-Id: I9cc3c9d9324314d293f01f047882eb6be06e02dd

openstack/common/timeutils.py

@@ -25,18 +25,22 @@
 import iso8601
 
 
-TIME_FORMAT = "%Y-%m-%dT%H:%M:%S"
-PERFECT_TIME_FORMAT = "%Y-%m-%dT%H:%M:%S.%f"
+# ISO 8601 extended time format with microseconds
+_ISO8601_TIME_FORMAT_SUBSECOND = '%Y-%m-%dT%H:%M:%S.%f'
+_ISO8601_TIME_FORMAT = '%Y-%m-%dT%H:%M:%S'
+PERFECT_TIME_FORMAT = _ISO8601_TIME_FORMAT_SUBSECOND
 
 
-def isotime(at=None):
+def isotime(at=None, subsecond=False):
     """Stringify time in ISO 8601 format"""
     if not at:
         at = utcnow()
-    str = at.strftime(TIME_FORMAT)
+    st = at.strftime(_ISO8601_TIME_FORMAT
+                     if not subsecond
+                     else _ISO8601_TIME_FORMAT_SUBSECOND)
     tz = at.tzinfo.tzname(None) if at.tzinfo else 'UTC'
-    str += ('Z' if tz == 'UTC' else tz)
-    return str
+    st += ('Z' if tz == 'UTC' else tz)
+    return st
 
 
 def parse_isotime(timestr):

tests/unit/test_timeutils.py

@@ -30,7 +30,10 @@ class TimeUtilsTest(utils.BaseTestCase):
     def setUp(self):
         super(TimeUtilsTest, self).setUp()
         self.skynet_self_aware_time_str = '1997-08-29T06:14:00Z'
+        self.skynet_self_aware_time_ms_str = '1997-08-29T06:14:00.000123Z'
         self.skynet_self_aware_time = datetime.datetime(1997, 8, 29, 6, 14, 0)
+        self.skynet_self_aware_ms_time = datetime.datetime(
+            1997, 8, 29, 6, 14, 0, 123)
         self.one_minute_before = datetime.datetime(1997, 8, 29, 6, 13, 0)
         self.one_minute_after = datetime.datetime(1997, 8, 29, 6, 15, 0)
         self.skynet_self_aware_time_perfect_str = '1997-08-29T06:14:00.000000'
@@ -44,12 +47,24 @@ def test_isotime(self):
             dt = timeutils.isotime()
             self.assertEqual(dt, self.skynet_self_aware_time_str)
 
+    def test_isotimei_micro_second_precision(self):
+        with mock.patch('datetime.datetime') as datetime_mock:
+            datetime_mock.utcnow.return_value = self.skynet_self_aware_ms_time
+            dt = timeutils.isotime(subsecond=True)
+            self.assertEqual(dt, self.skynet_self_aware_time_ms_str)
+
     def test_parse_isotime(self):
         expect = timeutils.parse_isotime(self.skynet_self_aware_time_str)
         skynet_self_aware_time_utc = self.skynet_self_aware_time.replace(
             tzinfo=iso8601.iso8601.UTC)
         self.assertEqual(skynet_self_aware_time_utc, expect)
 
+    def test_parse_isotime_micro_second_precision(self):
+        expect = timeutils.parse_isotime(self.skynet_self_aware_time_ms_str)
+        skynet_self_aware_time_ms_utc = self.skynet_self_aware_ms_time.replace(
+            tzinfo=iso8601.iso8601.UTC)
+        self.assertEqual(skynet_self_aware_time_ms_utc, expect)
+
     def test_strtime(self):
         expect = timeutils.strtime(self.skynet_self_aware_time_perfect)
         self.assertEqual(self.skynet_self_aware_time_perfect_str, expect)