130 lines
5.2 KiB
Python
130 lines
5.2 KiB
Python
# Copyright (c) 2011-2012 OpenStack Foundation.
|
|
# 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 oslo_log import log as logging
|
|
|
|
from cinder.scheduler import base_handler
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
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 overridden 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
|
|
|
|
# Set to true in a subclass if a filter only needs to be run once
|
|
# for each request rather than for each instance
|
|
run_filter_once_per_request = False
|
|
|
|
def run_filter_for_index(self, index):
|
|
"""Return True if the filter needs to be run for n-th instances.
|
|
|
|
Only need to override this if a filter needs anything other than
|
|
"first only" or "all" behaviour.
|
|
"""
|
|
return not (self.run_filter_once_per_request and index > 0)
|
|
|
|
|
|
class BaseFilterHandler(base_handler.BaseHandler):
|
|
"""Base class to handle loading filter classes.
|
|
|
|
This class should be subclassed where one needs to use filters.
|
|
"""
|
|
|
|
def _log_filtration(self, full_filter_results,
|
|
part_filter_results, filter_properties):
|
|
# Log the filtration history
|
|
rspec = filter_properties.get("request_spec", {})
|
|
msg_dict = {"vol_id": rspec.get("volume_id", ""),
|
|
"str_results": full_filter_results}
|
|
LOG.debug("Filtering removed all hosts for the request with "
|
|
"volume ID '%(vol_id)s'. Filter results: %(str_results)s",
|
|
msg_dict)
|
|
msg_dict["str_results"] = ', '.join(
|
|
"%(cls_name)s: (start: %(start)s, end: %(end)s)" % {
|
|
"cls_name": value[0], "start": value[1], "end": value[2]}
|
|
for value in part_filter_results)
|
|
LOG.info("Filtering removed all hosts for the request with "
|
|
"volume ID '%(vol_id)s'. Filter results: %(str_results)s",
|
|
msg_dict)
|
|
|
|
def get_filtered_objects(self, filter_classes, objs,
|
|
filter_properties, index=0):
|
|
"""Get objects after filter
|
|
|
|
:param filter_classes: filters that will be used to filter the
|
|
objects
|
|
:param objs: objects that will be filtered
|
|
:param filter_properties: client filter properties
|
|
:param index: This value needs to be increased in the caller
|
|
function of get_filtered_objects when handling
|
|
each resource.
|
|
"""
|
|
list_objs = list(objs)
|
|
LOG.debug("Starting with %d host(s)", len(list_objs))
|
|
# The 'part_filter_results' list just tracks the number of hosts
|
|
# before and after the filter, unless the filter returns zero
|
|
# hosts, in which it records the host/nodename for the last batch
|
|
# that was removed. Since the full_filter_results can be very large,
|
|
# it is only recorded if the LOG level is set to debug.
|
|
part_filter_results = []
|
|
full_filter_results = []
|
|
for filter_cls in filter_classes:
|
|
cls_name = filter_cls.__name__
|
|
start_count = len(list_objs)
|
|
filter_class = filter_cls()
|
|
|
|
if filter_class.run_filter_for_index(index):
|
|
objs = filter_class.filter_all(list_objs, filter_properties)
|
|
if objs is None:
|
|
LOG.info("Filter %s returned 0 hosts", cls_name)
|
|
full_filter_results.append((cls_name, None))
|
|
list_objs = None
|
|
break
|
|
|
|
list_objs = list(objs)
|
|
end_count = len(list_objs)
|
|
part_filter_results.append((cls_name, start_count, end_count))
|
|
remaining = [getattr(obj, "host", obj)
|
|
for obj in list_objs]
|
|
full_filter_results.append((cls_name, remaining))
|
|
|
|
LOG.debug("Filter %(cls_name)s returned "
|
|
"%(obj_len)d host(s)",
|
|
{'cls_name': cls_name, 'obj_len': len(list_objs)})
|
|
if not list_objs:
|
|
self._log_filtration(full_filter_results,
|
|
part_filter_results, filter_properties)
|
|
return list_objs
|