deb-ceilometer/ceilometer/transformer/__init__.py
gordon chung c79b598259 add flexible grouping key
all transformers will now require a grouping key. the pipeline will
take grouping keys from all transformers in it's definition. using
the set of keys, the values will be pulled from the datapoint, hashed,
and sent to a pipeline. if no transformers are applied, samples will
be grouped by resource_id and events will be grouped by event_type.

Implement blueprint distributed-coordinated-notifications

Change-Id: Ief462d19655c238e5951881a58e183084d37ac13
2015-08-20 08:46:45 -04:00

81 lines
2.4 KiB
Python

#
# Copyright 2013 Intel Corp.
#
# 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
import collections
import six
@six.add_metaclass(abc.ABCMeta)
class TransformerBase(object):
"""Base class for plugins that transform the sample."""
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, sample):
"""Transform a sample.
:param context: Passed from the data collector.
:param sample: A sample.
"""
@abc.abstractproperty
def grouping_keys(self):
"""Keys used to group transformer."""
def flush(self, context):
"""Flush samples cached previously.
:param context: Passed from the data collector.
"""
return []
class Namespace(object):
"""Encapsulates the namespace.
Encapsulation is done by wrapping the evaluation of the configured rule.
This allows nested dicts to be accessed in the attribute style,
and missing attributes to yield false when used in a boolean expression.
"""
def __init__(self, seed):
self.__dict__ = collections.defaultdict(lambda: Namespace({}))
self.__dict__.update(seed)
for k, v in six.iteritems(self.__dict__):
if isinstance(v, dict):
self.__dict__[k] = Namespace(v)
def __getattr__(self, attr):
return self.__dict__[attr]
def __getitem__(self, key):
return self.__dict__[key]
def __nonzero__(self):
return len(self.__dict__) > 0
__bool__ = __nonzero__