oslo.utils/oslo_utils/fixture.py
Ben Nemec 9fdcf64720 Fix docstring formatting nit in uuidsentinel
This doesn't actually appear in the docs because it's a private class,
but if we ever made it public we want it to format the code block
correctly.

Change-Id: Ia79b58d6d7847b65f946763c82a25ce8d8e581fb
2018-08-28 15:25:18 +00:00

93 lines
2.9 KiB
Python

# Copyright 2015 OpenStack Foundation
# 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.
"""
Test fixtures.
.. versionadded:: 1.3
"""
import threading
import fixtures
from oslo_utils import timeutils
from oslo_utils import uuidutils
class TimeFixture(fixtures.Fixture):
"""A fixture for overriding the time returned by timeutils.utcnow().
:param override_time: datetime instance or list thereof. If not given,
defaults to the current UTC time.
"""
def __init__(self, override_time=None):
super(TimeFixture, self).__init__()
self._override_time = override_time
def setUp(self):
super(TimeFixture, self).setUp()
timeutils.set_time_override(self._override_time)
self.addCleanup(timeutils.clear_time_override)
def advance_time_delta(self, timedelta):
"""Advance overridden time using a datetime.timedelta."""
timeutils.advance_time_delta(timedelta)
def advance_time_seconds(self, seconds):
"""Advance overridden time by seconds."""
timeutils.advance_time_seconds(seconds)
class _UUIDSentinels(object):
"""Registry of dynamically created, named, random UUID strings.
An instance of this class will dynamically generate attributes as they are
referenced, associating a random UUID string with each. Thereafter,
referring to the same attribute will give the same UUID for the life of the
instance. Plan accordingly.
Usage::
from oslo_utils.fixture import uuidsentinel as uuids
...
foo = uuids.foo
do_a_thing(foo)
# Referencing the same sentinel again gives the same value
assert foo == uuids.foo
# But a different one will be different
assert foo != uuids.bar
"""
def __init__(self):
self._sentinels = {}
self._lock = threading.Lock()
def __getattr__(self, name):
if name.startswith('_'):
raise ValueError('Sentinels must not start with _')
with self._lock:
if name not in self._sentinels:
self._sentinels[name] = uuidutils.generate_uuid()
return self._sentinels[name]
# Singleton sentinel instance. Caveat emptor: using this multiple times in the
# same process (including across multiple modules) will result in the same
# values
uuidsentinel = _UUIDSentinels()