gantt/nova/filters.py
Chris Behrens 770acb12ab Refactor scheduling filters
This changes the scheduling filters to use the code in nova/loadables.py
to locate filtering classes.  This also creates some base functionality
in nova/filters.py to be used by both the host scheduler and the cells
scheduler.

The scheduler_available_filters default has changed to
'nova.scheduler.filters.all_filters' which is better named compared to
the old setting of 'standard_filters'.  The old method is still
supported for those that have put it explicitly in their configs, but
it's marked as deprecated.

DocImpact

Change-Id: I84fdeafdba0275ab4b25f8857563bd7b1494bb69
2012-11-14 19:04:12 +00:00

54 lines
1.7 KiB
Python

# Copyright (c) 2011-2012 OpenStack, LLC.
# All Rights Reserved.
#
# 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.
"""
Filter support
"""
from nova import loadables
class BaseFilter(object):
"""Base class for all filter classes."""
def _filter_one(self, obj, filter_properties):
"""Return True if it passes the filter, False otherwise.
Override this in a subclass.
"""
return True
def filter_all(self, filter_obj_list, filter_properties):
"""Yield objects that pass the filter.
Can be overriden in a subclass, if you need to base filtering
decisions on all objects. Otherwise, one can just override
_filter_one() to filter a single object.
"""
for obj in filter_obj_list:
if self._filter_one(obj, filter_properties):
yield obj
class BaseFilterHandler(loadables.BaseLoader):
"""Base class to handle loading filter classes.
This class should be subclassed where one needs to use filters.
"""
def get_filtered_objects(self, filter_classes, objs,
filter_properties):
for filter_cls in filter_classes:
objs = filter_cls().filter_all(objs, filter_properties)
return list(objs)