Files
deb-python-taskflow/taskflow/engines/action_engine/task_action.py
Anastasia Karpinska 86920f05b2 Exception when scheduling task with invalid state
Since GraphAnalyzer checks for tasks and retries to be scheduled we
have to raise an exception when it tries to schedule a task with
invalid state.

Change-Id: Ib9eb1ffaf7d0d1b3fd6a9b49504ef508778dd3ee
2014-03-28 16:03:47 +02:00

101 lines
4.1 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 exceptions
from taskflow import states
from taskflow.utils import misc
LOG = logging.getLogger(__name__)
SAVE_RESULT_STATES = (states.SUCCESS, states.FAILURE)
class TaskAction(object):
def __init__(self, storage, task_executor, notifier):
self._storage = storage
self._task_executor = task_executor
self._notifier = notifier
def change_state(self, task, state, result=None, progress=None):
old_state = self._storage.get_atom_state(task.name)
if old_state == state:
return state != states.PENDING
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)
return True
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):
if not self.change_state(task, states.RUNNING, progress=0.0):
raise exceptions.InvalidState("Task %s is in invalid state and"
" can't be executed" % task.name)
kwargs = self._storage.fetch_mapped_args(task.rebind)
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, misc.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):
if not self.change_state(task, states.REVERTING, progress=0.0):
raise exceptions.InvalidState("Task %s is in invalid state and"
" can't be reverted" % task.name)
kwargs = self._storage.fetch_mapped_args(task.rebind)
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, misc.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)