aodh/ceilometer/transformer/__init__.py
Julien Danjou d06dcc69f5 Enable pep8 H403 checks
What a better thing to do on a Friday afternoon to chill out before the
week-end?

Change-Id: Ie264d2bff02794d80ddbecb95a6b2ff9a3840d44
2013-06-14 17:15:52 +02:00

71 lines
2.2 KiB
Python

# -*- encoding: utf-8 -*-
#
# Copyright © 2013 Intel Corp.
#
# Author: Yunhong Jiang <yunhong.jiang@intel.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.
import abc
from stevedore import extension
class TransformerExtensionManager(extension.ExtensionManager):
def __init__(self, namespace):
super(TransformerExtensionManager, self).__init__(
namespace=namespace,
invoke_on_load=False,
invoke_args=(),
invoke_kwds={}
)
self.by_name = dict((e.name, e) for e in self.extensions)
def get_ext(self, name):
return self.by_name[name]
class TransformerBase(object):
"""Base class for plugins that transform the counter."""
__metaclass__ = abc.ABCMeta
def __init__(self, **kwargs):
"""Setup transformer.
Each time a transformed is involved in a pipeline, a new transformer
instance is created and chained into the pipeline. i.e. transformer
instance is per pipeline. This helps if transformer need keep some
cache and per-pipeline information.
:param kwargs: The parameters that are defined in pipeline config file.
"""
super(TransformerBase, self).__init__()
@abc.abstractmethod
def handle_sample(self, context, counter, source):
"""Transform a counter.
:param context: Passed from the data collector.
:param counter: A counter.
:param source: Passed from data collector.
"""
def flush(self, context, source):
"""Flush counters cached previously.
:param context: Passed from the data collector.
:param source: Source of counters that are being published.
"""
return []