aea1f401eb
* Added missing period for doc strings * Correct syntax errors * Remove H402 from flake8 ignore list Change-Id: Ia8592bf99378e3658d6cca2ceb148bf9eb0b5de8
86 lines
3.2 KiB
Python
86 lines
3.2 KiB
Python
# -*- coding: utf-8 -*-
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (C) 2013 Rackspace Hosting Inc. All Rights Reserved.
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# Copyright (C) 2013 Yahoo! Inc. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import abc
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import six
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@six.add_metaclass(abc.ABCMeta)
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class JobBoard(object):
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"""A jobboard is an abstract representation of a place where jobs
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can be posted, reposted, claimed and transferred. There can be multiple
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implementations of this job board, depending on the desired semantics and
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capabilities of the underlying jobboard implementation.
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"""
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def __init__(self, name):
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self._name = name
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@property
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def name(self):
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"""The non-uniquely identifying name of this jobboard."""
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return self._name
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@abc.abstractmethod
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def consume(self, job):
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"""Permanently (and atomically) removes a job from the jobboard,
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signaling that this job has been completed by the entity assigned
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to that job.
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Only the entity that has claimed that job is able to consume a job.
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A job that has been consumed can not be reclaimed or reposted by
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another entity (job postings are immutable). Any entity consuming
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a unclaimed job (or a job they do not own) will cause an exception.
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"""
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@abc.abstractmethod
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def post(self, job):
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"""Atomically posts a given job to the jobboard, allowing others to
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attempt to claim that job (and subsequently work on that job).
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Once a job has been posted it can only be removed by consuming that
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job (after that job is claimed). Any entity can post or propose jobs
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to the jobboard (in the future this may be restricted).
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"""
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@abc.abstractmethod
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def claim(self, job, who):
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"""Atomically attempts to claim the given job for the entity and either
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succeeds or fails at claiming by throwing corresponding exceptions.
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If a job is claimed it is expected that the entity that claims that job
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will at sometime in the future work on that jobs flows and either fail
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at completing them (resulting in a reposting) or consume that job from
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the jobboard (signaling its completion).
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"""
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@abc.abstractmethod
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def repost(self, job):
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"""Atomically reposts the given job on the jobboard, allowing that job
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to be reclaimed by others. This would typically occur if the entity
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that has claimed the job has failed or is unable to complete the job
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or jobs it has claimed.
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Only the entity that has claimed that job can repost a job. Any entity
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reposting a unclaimed job (or a job they do not own) will cause an
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exception.
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"""
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