Files
deb-python-taskflow/taskflow/engines/action_engine/task_action.py
Joshua Harlow 3c9871d8c3 Remove direct usage of the deprecated failure location
Internally we should be using the new location and not the
deprecated location wherever possible. This avoids emitting
warnings messages on our own code, which is a dirty habit.

Change-Id: Idac5a772eca7529d92542ada3be1cea092880e25
2014-10-21 15:37:44 -07:00

122 lines
5.1 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2012-2013 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 logging
from taskflow import states
from taskflow.types import failure
LOG = logging.getLogger(__name__)
SAVE_RESULT_STATES = (states.SUCCESS, states.FAILURE)
class TaskAction(object):
def __init__(self, storage, task_executor, notifier, walker_factory):
self._storage = storage
self._task_executor = task_executor
self._notifier = notifier
self._walker_factory = walker_factory
def _is_identity_transition(self, state, task, progress):
if state in SAVE_RESULT_STATES:
# saving result is never identity transition
return False
old_state = self._storage.get_atom_state(task.name)
if state != old_state:
# changing state is not identity transition by definition
return False
# NOTE(imelnikov): last thing to check is that the progress has
# changed, which means progress is not None and is different from
# what is stored in the database.
if progress is None:
return False
old_progress = self._storage.get_task_progress(task.name)
if old_progress != progress:
return False
return True
def change_state(self, task, state, result=None, progress=None):
if self._is_identity_transition(state, task, progress):
# NOTE(imelnikov): ignore identity transitions in order
# to avoid extra write to storage backend and, what's
# more important, extra notifications
return
if state in SAVE_RESULT_STATES:
self._storage.save(task.name, result, state)
else:
self._storage.set_atom_state(task.name, state)
if progress is not None:
self._storage.set_task_progress(task.name, progress)
task_uuid = self._storage.get_atom_uuid(task.name)
details = dict(task_name=task.name,
task_uuid=task_uuid,
result=result)
self._notifier.notify(state, details)
if progress is not None:
task.update_progress(progress)
def _on_update_progress(self, task, event_data, progress, **kwargs):
"""Should be called when task updates its progress."""
try:
self._storage.set_task_progress(task.name, 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 to %0.3f",
task, progress)
def schedule_execution(self, task):
self.change_state(task, states.RUNNING, progress=0.0)
scope_walker = self._walker_factory(task)
kwargs = self._storage.fetch_mapped_args(task.rebind,
atom_name=task.name,
scope_walker=scope_walker)
task_uuid = self._storage.get_atom_uuid(task.name)
return self._task_executor.execute_task(task, task_uuid, kwargs,
self._on_update_progress)
def complete_execution(self, task, result):
if isinstance(result, failure.Failure):
self.change_state(task, states.FAILURE, result=result)
else:
self.change_state(task, states.SUCCESS,
result=result, progress=1.0)
def schedule_reversion(self, task):
self.change_state(task, states.REVERTING, progress=0.0)
scope_walker = self._walker_factory(task)
kwargs = self._storage.fetch_mapped_args(task.rebind,
atom_name=task.name,
scope_walker=scope_walker)
task_uuid = self._storage.get_atom_uuid(task.name)
task_result = self._storage.get(task.name)
failures = self._storage.get_failures()
future = self._task_executor.revert_task(task, task_uuid, kwargs,
task_result, failures,
self._on_update_progress)
return future
def complete_reversion(self, task, rev_result):
if isinstance(rev_result, failure.Failure):
self.change_state(task, states.FAILURE)
else:
self.change_state(task, states.REVERTED, progress=1.0)
def wait_for_any(self, fs, timeout):
return self._task_executor.wait_for_any(fs, timeout)