Files
deb-python-taskflow/taskflow/patterns/distributed_flow.py
Angus Salkeld 339e43d03b Fix the current flake8 errors
The test pip ordering was resulting in the pep8 rules not really
running so this fixes that up and the resulting errors so we can
get a clean run.

Change-Id: Icc27be05cd513c4f04135c7e768007dbf9d07b10
2013-06-26 11:03:23 +10:00

88 lines
3.2 KiB
Python

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
# Copyright (C) 2013 Rackspace Hosting Inc. 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.
import logging
from taskflow import logbook
from celery import chord
LOG = logging.getLogger(__name__)
class Flow(object):
"""A linear chain of independent tasks that can be applied as one unit or
rolled back as one unit."""
def __init__(self, name, parents=None):
self.name = name
self.root = None
self._tasks = []
logbook.add_workflow(name)
def chain_listeners(self, context, initial_task, callback_task):
""" Register one listener for a task """
if self.root is None:
initial_task.name = '%s.%s' % (self.name, initial_task.name)
self.root = initial_task.s(context)
self._tasks.append(initial_task)
LOG.info('WF %s root task set to %s', self.name, initial_task.name)
callback_task.name = '%s.%s' % (self.name, callback_task.name)
self._tasks.append(callback_task)
initial_task.link(callback_task.s(context))
def split_listeners(self, context, initial_task, callback_tasks):
""" Register multiple listeners for one task """
if self.root is None:
initial_task.name = '%s.%s' % (self.name, initial_task.name)
self.root = initial_task.s(context)
self._tasks.append(initial_task)
LOG.info('WF %s root task set to %s', self.name, initial_task.name)
for task in callback_tasks:
task.name = '%s.%s' % (self.name, task.name)
self._tasks.append(task)
initial_task.link(task.s(context))
def merge_listeners(self, context, initial_tasks, callback_task):
""" Register one listener for multiple tasks """
header = []
if self.root is None:
self.root = []
for task in initial_tasks:
task.name = '%s.%s' % (self.name, task.name)
self._tasks.append(task)
header.append(task.s(context))
if isinstance(self.root, list):
self.root.append(task.s(context))
LOG.info('WF %s added root task %s' %
(self.name, task.name))
callback_task.name = '%s.%s' % (self.name, callback_task.name)
self._tasks.append(callback_task)
# TODO(jlucci): Need to set up chord so that it's not executed
# immediately.
c = chord(header, body=callback_task)
def run(self, context, *args, **kwargs):
""" Start root task and kick off workflow """
self.root(context)
LOG.info('WF %s has been started' % (self.name,))