fuel-web/nailgun/nailgun/orchestrator/priority_serializers.py

68 lines
2.0 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2013 Mirantis, Inc.
#
# 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.
class Priority(object):
"""Returns a priority sequence from hightest to lowest.
Node with priority 0 will be deployed first. We have a big step
because we want to allow user redefine deployment order and
he can use free space between prioriries.
:param step: an increment step
"""
#: default priority step
default_step = 100
def __init__(self, step=default_step):
self._step = step
self._priority = 0
def next(self):
self._priority += self._step
return self._priority
@property
def current(self):
return self._priority
class PriorityStrategy(object):
"""Set priorities for sequence of tasks using some strategy"""
def __init__(self):
#: priority sequence generator
self._priority = Priority()
def one_by_one(self, tasks):
"""Deploy given tasks one by one."""
for t in tasks:
t['priority'] = self._priority.next()
def in_parallel(self, tasks):
"""Deploy given tasks in parallel mode."""
self._priority.next()
for t in tasks:
t['priority'] = self._priority.current
def in_parallel_by(self, tasks, amount):
"""Deploy given nodes in parallel by chunks."""
for index, task in enumerate(tasks):
if index % amount == 0:
self._priority.next()
task['priority'] = self._priority.current