aodh/ceilometer/compute/plugin.py
liuqing 522b7ffb32 Remove redudent space in doc string
In file ceilometer/compute/plugin.py, there are some redudent
spaces, the patch will remove them and make the code more pleasure:)

Change-Id: I1a896366bab3344422d905b30b24cbb8f257ddde
2014-07-22 16:33:31 +08:00

55 lines
1.8 KiB
Python

#
# Copyright 2012 New Dream Network, LLC (DreamHost)
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
#
# 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.
"""Base class for plugins used by the compute agent.
"""
import abc
import six
from ceilometer.openstack.common import timeutils
from ceilometer import plugin
@six.add_metaclass(abc.ABCMeta)
class ComputePollster(plugin.PollsterBase):
"""Base class for plugins.
It supports the polling API on the compute node.
"""
@abc.abstractmethod
def get_samples(self, manager, cache, resources):
"""Return a sequence of Counter instances from polling the resources.
:param manager: The service manager invoking the plugin
:param cache: A dictionary for passing data between plugins
:param resources: The resources to examine (expected to be instances)
"""
def _record_poll_time(self):
"""Method records current time as the poll time.
:return: time in seconds since the last poll time was recorded
"""
current_time = timeutils.utcnow()
duration = None
if hasattr(self, '_last_poll_time'):
duration = timeutils.delta_seconds(self._last_poll_time,
current_time)
self._last_poll_time = current_time
return duration