summaryrefslogtreecommitdiffstats
path: root/nova/scheduler/filters/__init__.py
blob: 0bd0698264b4afd693c32b223954df5d77139369 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
# Copyright (c) 2011 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.

"""
Scheduler host filters
"""

from nova import filters
from nova.openstack.common import log as logging

LOG = logging.getLogger(__name__)


class BaseHostFilter(filters.BaseFilter):
    """Base class for host filters."""
    def _filter_one(self, obj, filter_properties):
        """Return True if the object passes the filter, otherwise False."""
        return self.host_passes(obj, filter_properties)

    def host_passes(self, host_state, filter_properties):
        """Return True if the HostState passes the filter, otherwise False.
        Override this in a subclass.
        """
        raise NotImplementedError()


class HostFilterHandler(filters.BaseFilterHandler):
    def __init__(self):
        super(HostFilterHandler, self).__init__(BaseHostFilter)


def all_filters():
    """Return a list of filter classes found in this directory.

    This method is used as the default for available scheduler filters
    and should return a list of all filter classes available.
    """
    return HostFilterHandler().get_all_classes()


def standard_filters():
    """Deprecated.  Configs should change to use all_filters()."""
    LOG.deprecated(_("Use 'nova.scheduler.filters.all_filters' instead "
            "of 'nova.scheduler.filters.standard_filters'"))
    return all_filters()