843b487736
Instead of requiring iteration to be able to list new jobs and existing jobs so that they can be claimed, allow for attaching callbacks to the jobboard where instead of requiring iteration those callbacks will be automatically called by the jobboard internally when events are recieved. Breaking change: renames transition notifier to notifier since it is really not just a notifier for transitions but is a generic notifier of events occuring (and details about those events). This is an internal api so its not expected that this will cause any issues (it's not expected for external users to be creating instances of this class). Implements bp board-notification Change-Id: I2384d5e335ed9d17e29fec9a78699e3156fa225c
82 lines
2.6 KiB
Python
82 lines
2.6 KiB
Python
# -*- coding: utf-8 -*-
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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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from taskflow.utils import misc
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@six.add_metaclass(abc.ABCMeta)
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class EngineBase(object):
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"""Base for all engines implementations."""
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def __init__(self, flow, flow_detail, backend, conf):
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self._flow = flow
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self._flow_detail = flow_detail
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self._backend = backend
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if not conf:
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self._conf = {}
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else:
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self._conf = dict(conf)
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self._storage = None
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self.notifier = misc.Notifier()
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self.task_notifier = misc.Notifier()
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@property
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def storage(self):
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"""The storage unit for this flow."""
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if self._storage is None:
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self._storage = self._storage_cls(self._flow_detail, self._backend)
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return self._storage
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@abc.abstractproperty
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def _storage_cls(self):
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"""Storage class that will be used to generate storage objects."""
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@abc.abstractmethod
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def compile(self):
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"""Compiles the contained flow into a structure which the engine can
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use to run or if this can not be done then an exception is thrown
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indicating why this compilation could not be achieved.
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"""
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@abc.abstractmethod
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def prepare(self):
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"""Performs any pre-run, but post-compilation actions.
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NOTE(harlowja): During preparation it is currently assumed that the
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underlying storage will be initialized, all final dependencies
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will be verified, the tasks will be reset and the engine will enter
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the PENDING state.
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"""
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@abc.abstractmethod
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def run(self):
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"""Runs the flow in the engine to completion (or die trying)."""
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@abc.abstractmethod
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def suspend(self):
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"""Attempts to suspend the engine.
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If the engine is currently running tasks then this will attempt to
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suspend future work from being started (currently active tasks can
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not currently be preempted) and move the engine into a suspend state
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which can then later be resumed from.
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"""
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