Files
deb-python-taskflow/taskflow/engines/worker_based/protocol.py
Stanislav Kudriashev 88e7a40052 Update request expired property docsting
Change-Id: If5a9881227e3fe5484df63b3117e078321365699
2014-03-14 11:32:39 +02:00

127 lines
4.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! 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.
from concurrent import futures
from taskflow.engines.action_engine import executor
from taskflow.utils import misc
from taskflow.utils import persistence_utils as pu
from taskflow.utils import reflection
# NOTE(skudriashev): This is protocol events, not related to the task states.
PENDING = 'PENDING'
RUNNING = 'RUNNING'
SUCCESS = 'SUCCESS'
FAILURE = 'FAILURE'
PROGRESS = 'PROGRESS'
# Remote task actions.
EXECUTE = 'execute'
REVERT = 'revert'
# Remote task action to event map.
ACTION_TO_EVENT = {
EXECUTE: executor.EXECUTED,
REVERT: executor.REVERTED
}
# NOTE(skudriashev): A timeout which specifies request expiration period.
REQUEST_TIMEOUT = 60
# NOTE(skudriashev): A timeout which controls for how long a queue can be
# unused before it is automatically deleted. Unused means the queue has no
# consumers, the queue has not been redeclared, the `queue.get` has not been
# invoked for a duration of at least the expiration period. In our case this
# period is equal to the request timeout, once request is expired - queue is
# no longer needed.
QUEUE_EXPIRE_TIMEOUT = REQUEST_TIMEOUT
class Request(object):
"""Represents request with execution results. Every request is created in
the PENDING state and is expired within the given timeout.
"""
def __init__(self, task, uuid, action, arguments, progress_callback,
timeout, **kwargs):
self._task = task
self._task_cls = reflection.get_class_name(task)
self._uuid = uuid
self._action = action
self._event = ACTION_TO_EVENT[action]
self._arguments = arguments
self._progress_callback = progress_callback
self._kwargs = kwargs
self._watch = misc.StopWatch(duration=timeout).start()
self._state = PENDING
self.result = futures.Future()
def __repr__(self):
return "%s:%s" % (self._task_cls, self._action)
@property
def uuid(self):
return self._uuid
@property
def task_cls(self):
return self._task_cls
@property
def expired(self):
"""Check if request has expired.
When new request is created its state is set to the PENDING, creation
time is stored and timeout is given via constructor arguments.
Request is considered to be expired when it is in the PENDING state
for more then the given timeout (it is not considered to be expired
in any other state).
"""
if self._state == PENDING:
return self._watch.expired()
return False
def to_dict(self):
"""Return json-serializable request, converting all `misc.Failure`
objects into dictionaries.
"""
request = dict(task_cls=self._task_cls, task_name=self._task.name,
task_version=self._task.version, action=self._action,
arguments=self._arguments)
if 'result' in self._kwargs:
result = self._kwargs['result']
if isinstance(result, misc.Failure):
request['result'] = ('failure', pu.failure_to_dict(result))
else:
request['result'] = ('success', result)
if 'failures' in self._kwargs:
failures = self._kwargs['failures']
request['failures'] = {}
for task, failure in failures.items():
request['failures'][task] = pu.failure_to_dict(failure)
return request
def set_result(self, result):
self.result.set_result((self._task, self._event, result))
def set_running(self):
self._state = RUNNING
self._watch.stop()
def on_progress(self, event_data, progress):
self._progress_callback(self._task, event_data, progress)