Files
deb-python-taskflow/taskflow/engines/action_engine/task_action.py
Greg Hill 46fc1dd9ee add the ability to inject arguments into tasks at task creation
Similar to the rebind functionality that lets you rename parameters
from those in the store, inject lets you inject arbitrary key/value
pairs that will be sent to your task at task creation time.  This allows
for flow and flow factories to reuse tasks with differing parameters
without jumping through a lot of hoops.

Change-Id: If167962811d22054b89d7d35a33d4ec5cb2cd648
Implements: blueprint wbe-workers-endpoints-constructors
2014-05-28 09:24:49 -05:00

103 lines
4.3 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_name=task.name)
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_name=task.name)
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)