Files
deb-python-taskflow/taskflow/engines/action_engine/task_action.py
Ivan A. Melnikov ac23e607ae Be more careful when passing result to revert()
Instead of passing result as separate keyword argument (which may
lead to strange TypeError exception) we put it to kwargs dict.

Change-Id: I899763e047badeadfd367aa1f06ba4cf6c1b0951
2013-10-24 17:07:49 +04:00

125 lines
4.6 KiB
Python

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (C) 2012 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.
import contextlib
import logging
from taskflow.engines.action_engine import base_action as base
from taskflow.openstack.common import excutils
from taskflow import states
from taskflow.utils import misc
LOG = logging.getLogger(__name__)
RESET_TASK_STATES = (states.PENDING,)
SAVE_RESULT_STATES = (states.SUCCESS, states.FAILURE)
@contextlib.contextmanager
def _autobind(task, bind_name, bind_func, **kwargs):
try:
task.bind(bind_name, bind_func, **kwargs)
yield task
finally:
task.unbind(bind_name, bind_func)
class TaskAction(base.Action):
def __init__(self, task, task_id):
self._task = task
self._id = task_id
@property
def name(self):
return self._task.name
@property
def uuid(self):
return self._id
def _change_state(self, engine, state, result=None, progress=None):
"""Update result and change state."""
old_state = engine.storage.get_task_state(self.uuid)
if not states.check_task_transition(old_state, state):
return False
if state in RESET_TASK_STATES:
engine.storage.reset(self.uuid)
if state in SAVE_RESULT_STATES:
engine.storage.save(self.uuid, result, state)
else:
engine.storage.set_task_state(self.uuid, state)
if progress is not None:
engine.storage.set_task_progress(self.uuid, progress)
engine._on_task_state_change(self, state, result=result)
return True
def _on_update_progress(self, task, event_data, progress, **kwargs):
"""Update task progress value that stored in engine."""
try:
engine = event_data['engine']
engine.storage.set_task_progress(self.uuid, progress, kwargs)
except Exception:
# Update progress callbacks should never fail, so capture and log
# the emitted exception instead of raising it.
LOG.exception("Failed setting task progress for %s (%s) to %0.3f",
task, self.uuid, progress)
def _change_state_update_task(self, engine, state, progress, result=None):
stated_changed = self._change_state(engine, state,
result=result, progress=progress)
if not stated_changed:
return False
self._task.update_progress(progress)
return True
def execute(self, engine):
if not self._change_state_update_task(engine, states.RUNNING, 0.0):
return
with _autobind(self._task,
'update_progress', self._on_update_progress,
engine=engine):
try:
kwargs = engine.storage.fetch_mapped_args(self._task.rebind)
result = self._task.execute(**kwargs)
except Exception:
failure = misc.Failure()
self._change_state(engine, states.FAILURE, result=failure)
failure.reraise()
self._change_state_update_task(engine, states.SUCCESS, 1.0,
result=result)
def revert(self, engine):
if not self._change_state_update_task(engine, states.REVERTING, 0.0):
# NOTE(imelnikov): in all the other states, the task
# execution was at least attempted, so we should give
# task a chance for cleanup
return
with _autobind(self._task,
'update_progress', self._on_update_progress,
engine=engine):
kwargs = engine.storage.fetch_mapped_args(self._task.rebind)
kwargs['result'] = engine.storage.get(self._id)
try:
self._task.revert(**kwargs)
except Exception:
with excutils.save_and_reraise_exception():
self._change_state(engine, states.FAILURE)
self._change_state_update_task(engine, states.REVERTED, 1.0)
self._change_state_update_task(engine, states.PENDING, 0.0)