zun/zun/scheduler/base_filters.py
ShunliZhou 478e72dd74 Add scheduler hint
Add scheduler hint for server side.

Change-Id: Ia612b3585efc74a9d52432ce790897447514c05e
2017-06-05 08:42:25 +08:00

112 lines
4.5 KiB
Python

# 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 zun.scheduler import loadables
LOG = logging.getLogger(__name__)
class BaseFilter(object):
"""Base class for all filter classes."""
def _filter_one(self, obj, container, extra_spec):
"""Return True if it passes the filter, False otherwise."""
return True
def filter_all(self, filter_obj_list, container, extra_spec):
"""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, container, extra_spec):
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 or False,
if the filter needs to be run for the "index-th" instance in a
request, return True. Only need to override this if a filter
needs anything other than "first only" or "all" behaviour.
"""
if self.run_filter_once_per_request and index > 0:
return False
else:
return True
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, filters, objs, container, extra_spec,
index=0):
list_objs = list(objs)
LOG.debug("Starting with %d host(s)", len(list_objs))
part_filter_results = []
full_filter_results = []
log_msg = "%(cls_name)s: (start: %(start)s, end: %(end)s)"
for filter_ in filters:
if filter_.run_filter_for_index(index):
cls_name = filter_.__class__.__name__
start_count = len(list_objs)
objs = filter_.filter_all(list_objs, container, extra_spec)
if objs is None:
LOG.debug("Filter %s says to stop filtering", cls_name)
return
list_objs = list(objs)
end_count = len(list_objs)
part_filter_results.append(log_msg % {"cls_name": cls_name,
"start": start_count,
"end": end_count})
if list_objs:
remaining = [(getattr(obj, "host", obj),
getattr(obj, "nodename", ""))
for obj in list_objs]
full_filter_results.append((cls_name, remaining))
else:
LOG.info("Filter %s returned 0 hosts", cls_name)
full_filter_results.append((cls_name, None))
break
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:
cnt_uuid = container.uuid
msg_dict = {"cnt_uuid": cnt_uuid,
"str_results": str(full_filter_results)}
full_msg = ("Filtering removed all hosts for the request with "
"container ID "
"'%(cnt_uuid)s'. Filter results: %(str_results)s"
) % msg_dict
msg_dict["str_results"] = str(part_filter_results)
part_msg = ("Filtering removed all hosts for the request with "
"container ID "
"'%(cnt_uuid)s'. Filter results: %(str_results)s"
) % msg_dict
LOG.debug(full_msg)
LOG.info(part_msg)
return list_objs