Replaces functions in utils.py with openstack/common/timeutils.py

Fixes bug #1008628

1. Edit openstack-common.conf and import nova/openstack/common/timeutils.py
2. Move time related functions from utils.py to timeutils.py
3. Replace following functions in utils.py with timeutils.py
- isotime
- parse_isotime
- strtime
- parse_strtime
- normalize_time
- is_older_than
- utcnow_ts
- utcnow
- set_time_override
- advance_time_delta
- advance_time_seconds
- clear_time_override
4. Remove datetime related functions and datetime related unittests

Change-Id: I9a92be286fb071b6237dd39495d88dae106e2ce0

1 files changed, 109 insertions, 0 deletions

diff --git a/nova/openstack/common/timeutils.py b/nova/openstack/common/timeutils.py
new file mode 100644
index 000000000..5eeaf70aa
--- /dev/null
+++ b/nova/openstack/common/timeutils.py
@@ -0,0 +1,109 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+Time related utilities and helper functions.
+"""
+
+import calendar
+import datetime
+import time
+
+import iso8601
+
+
+TIME_FORMAT = "%Y-%m-%dT%H:%M:%S"
+PERFECT_TIME_FORMAT = "%Y-%m-%dT%H:%M:%S.%f"
+
+
+def isotime(at=None):
+    """Stringify time in ISO 8601 format"""
+    if not at:
+        at = utcnow()
+    str = at.strftime(TIME_FORMAT)
+    tz = at.tzinfo.tzname(None) if at.tzinfo else 'UTC'
+    str += ('Z' if tz == 'UTC' else tz)
+    return str
+
+
+def parse_isotime(timestr):
+    """Parse time from ISO 8601 format"""
+    try:
+        return iso8601.parse_date(timestr)
+    except iso8601.ParseError as e:
+        raise ValueError(e.message)
+    except TypeError as e:
+        raise ValueError(e.message)
+
+
+def strtime(at=None, fmt=PERFECT_TIME_FORMAT):
+    """Returns formatted utcnow."""
+    if not at:
+        at = utcnow()
+    return at.strftime(fmt)
+
+
+def parse_strtime(timestr, fmt=PERFECT_TIME_FORMAT):
+    """Turn a formatted time back into a datetime."""
+    return datetime.datetime.strptime(timestr, fmt)
+
+
+def normalize_time(timestamp):
+    """Normalize time in arbitrary timezone to UTC"""
+    offset = timestamp.utcoffset()
+    return timestamp.replace(tzinfo=None) - offset if offset else timestamp
+
+
+def is_older_than(before, seconds):
+    """Return True if before is older than seconds."""
+    return utcnow() - before > datetime.timedelta(seconds=seconds)
+
+
+def utcnow_ts():
+    """Timestamp version of our utcnow function."""
+    return calendar.timegm(utcnow().timetuple())
+
+
+def utcnow():
+    """Overridable version of utils.utcnow."""
+    if utcnow.override_time:
+        return utcnow.override_time
+    return datetime.datetime.utcnow()
+
+
+utcnow.override_time = None
+
+
+def set_time_override(override_time=datetime.datetime.utcnow()):
+    """Override utils.utcnow to return a constant time."""
+    utcnow.override_time = override_time
+
+
+def advance_time_delta(timedelta):
+    """Advance overriden time using a datetime.timedelta."""
+    assert(not utcnow.override_time is None)
+    utcnow.override_time += timedelta
+
+
+def advance_time_seconds(seconds):
+    """Advance overriden time by seconds."""
+    advance_time_delta(datetime.timedelta(0, seconds))
+
+
+def clear_time_override():
+    """Remove the overridden time."""
+    utcnow.override_time = None