aodh/ceilometer/storage/base.py
Doug Hellmann b345efa0be Reduce complexity of storage engine API
In the process of implementing the first storage
backend I realized that the proposed API was
much more complicated than necessary. This
changeset streamlines the API to make it easier
to implement the plugins.

- add ceilometer.storage.get_connection() convenience function
- add get_volume_max() method
- clean up query arg handling by using EventFilter
- tighten up the DB query API by removing separate "by_user"
  and "by_project" methods

Change-Id: Id4dffcc59dbee44fd4670bbe55b5e3380ea240e5
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
2012-06-29 17:11:59 -04:00

130 lines
3.7 KiB
Python

# -*- encoding: utf-8 -*-
#
# 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 classes for storage engines
"""
import abc
from ceilometer import log
LOG = log.getLogger(__name__)
class StorageEngine(object):
"""Base class for storage engines.
"""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def register_opts(self, conf):
"""Register any configuration options used by this engine.
"""
@abc.abstractmethod
def get_connection(self, conf):
"""Return a Connection instance based on the configuration settings.
"""
class Connection(object):
"""Base class for storage system connections.
"""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def __init__(self, conf):
"""Constructor"""
@abc.abstractmethod
def record_metering_data(self, data):
"""Write the data to the backend storage system.
:param data: a dictionary such as returned by
ceilometer.meter.meter_message_from_counter
"""
@abc.abstractmethod
def get_users(self, source=None):
"""Return an iterable of user id strings.
:param source: Optional source filter.
"""
@abc.abstractmethod
def get_projects(self, source=None):
"""Return an iterable of project id strings.
:param source: Optional source filter.
"""
@abc.abstractmethod
def get_resources(self, user=None, project=None, source=None):
"""Return an iterable of dictionaries containing resource information.
{ 'resource_id': UUID of the resource,
'project_id': UUID of project owning the resource,
'user_id': UUID of user owning the resource,
'timestamp': UTC datetime of last update to the resource,
'metadata': most current metadata for the resource,
'meter': list of the meters reporting data for the resource,
}
:param user: Optional resource owner.
:param project: Optional resource owner.
:param source: Optional source filter.
"""
@abc.abstractmethod
def get_raw_events(self, event_filter):
"""Return an iterable of raw event data.
"""
@abc.abstractmethod
def get_volume_sum(self, event_filter):
"""Return the sum of the volume field for the events
described by the query parameters.
The filter must have a meter value set.
{ 'resource_id': UUID string for the resource,
'value': The sum for the volume.
}
"""
@abc.abstractmethod
def get_volume_max(self, event_filter):
"""Return the maximum of the volume field for the events
described by the query parameters.
The filter must have a meter value set.
{ 'resource_id': UUID string for the resource,
'value': The max for the volume.
}
"""
@abc.abstractmethod
def get_duration_sum(self, event_filter):
"""Return the sum of time for the events described by the
query parameters.
The filter must have a meter value set.
"""