deb-heat/heat/engine/timestamp.py
Zane Bitter 388ee0257f Fix garbled docstrings
The process of bringing us into compliance with the H405 pep8 rule has left
us with a lot of docstrings that either don't follow the recommendations of
PEP0257, are misleading, wrong, or nonsensical. This patch attempts to fix
them up.

Change-Id: Icfe90b5ba3102a7e13ab659038a8b2af9019e9e6
2015-11-10 11:12:36 -05:00

44 lines
1.6 KiB
Python

#
# 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.
from heat.common import exception
class Timestamp(object):
"""A descriptor for writing a timestamp to the database."""
def __init__(self, db_fetch, attribute):
"""Initialise the timestamp descriptor.
Initialise with a function to fetch the database representation of an
object (given a context and ID) and the name of the attribute to
retrieve.
"""
self.db_fetch = db_fetch
self.attribute = attribute
def __get__(self, obj, obj_class):
"""Get timestamp for the given object and class."""
if obj is None or obj.id is None:
return None
o = self.db_fetch(obj.context, obj.id)
return getattr(o, self.attribute)
def __set__(self, obj, timestamp):
"""Update the timestamp for the given object."""
if obj.id is None:
raise exception.ResourceNotAvailable(resource_name=obj.name)
o = self.db_fetch(obj.context, obj.id)
o.update_and_save({self.attribute: timestamp})