Files
deb-python-taskflow/taskflow/patterns/distributed_flow.py
Angus Salkeld a7482eaa18 Fix most of the hacking rules
Hacking rules: H302, H303, H304, H401, H404

Change-Id: I38e62696724a99c5ebe74d95d477999bd91a2c9a
2013-06-26 11:04:42 +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 celery
import logging
from taskflow import logbook
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.
celery.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,))