openstack/deb-python-taskflow
Code Issues Proposed changes

Merge "A few adjustments to the progress code"

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This commit is contained in:
Jenkins
2013-10-02 17:34:35 +00:00
committed by Gerrit Code Review
parent 58489a8fb1 c42b3a2ed5
commit 0b3de1c728
4 changed files with 213 additions and 54 deletions
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86
taskflow/engines/action_engine/task_action.py
View File

@@ -16,6 +16,9 @@
# 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 import exceptions
from taskflow.openstack.common import excutils
@@ -23,6 +26,22 @@ from taskflow.openstack.common import uuidutils
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)
ALREADY_FINISHED_STATES = (states.SUCCESS,)
NEVER_RAN_STATES = (states.PENDING,)
@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):
@@ -49,65 +68,66 @@ class TaskAction(base.Action):
def uuid(self):
return self._id
def _change_state(self, engine, state):
"""Check and update state of task."""
if state in (states.RUNNING, states.REVERTING, states.PENDING):
self._task.update_progress(0.0)
elif state in (states.SUCCESS, states.REVERTED):
self._task.update_progress(1.0)
engine.storage.set_task_state(self.uuid, state)
engine.on_task_state_change(self, state)
def _update_result(self, engine, state, result=None):
def _change_state(self, engine, state, result=None, progress=None):
"""Update result and change state."""
if state == states.PENDING:
if state in RESET_TASK_STATES:
engine.storage.reset(self.uuid)
else:
if state in SAVE_RESULT_STATES:
engine.storage.save(self.uuid, result, state)
engine.on_task_state_change(self, state, result)
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)
def _update_progress(self, task, event_data, progress, **kwargs):
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 _force_state(self, engine, state, progress, result=None):
self._change_state(engine, state, result=result, progress=progress)
self._task.update_progress(progress)
def execute(self, engine):
if engine.storage.get_task_state(self.uuid) == states.SUCCESS:
if engine.storage.get_task_state(self.uuid) in ALREADY_FINISHED_STATES:
# Skip tasks that already finished.
return
self._task.bind('update_progress', self._update_progress,
engine=engine)
self._force_state(engine, states.RUNNING, 0.0)
with _autobind(self._task,
'update_progress', self._on_update_progress,
engine=engine):
try:
kwargs = engine.storage.fetch_mapped_args(self._args_mapping)
self._change_state(engine, states.RUNNING)
result = self._task.execute(**kwargs)
except Exception:
failure = misc.Failure()
self._update_result(engine, states.FAILURE, failure)
self._change_state(engine, states.FAILURE, result=failure)
failure.reraise()
else:
self._update_result(engine, states.SUCCESS, result)
finally:
self._task.unbind('update_progress', self._update_progress)
self._force_state(engine, states.SUCCESS, 1.0, result=result)
def revert(self, engine):
if engine.storage.get_task_state(self.uuid) == states.PENDING:
if engine.storage.get_task_state(self.uuid) in NEVER_RAN_STATES:
# NOTE(imelnikov): in all the other states, the task
# execution was at least attempted, so we should give
# task a chance for cleanup
return
self._task.bind('update_progress', self._update_progress,
engine=engine)
self._force_state(engine, states.REVERTING, 0.0)
with _autobind(self._task,
'update_progress', self._on_update_progress,
engine=engine):
kwargs = engine.storage.fetch_mapped_args(self._args_mapping)
self._change_state(engine, states.REVERTING)
try:
self._task.revert(result=engine.storage.get(self._id),
**kwargs)
self._change_state(engine, states.REVERTED)
except Exception:
with excutils.save_and_reraise_exception():
self._change_state(engine, states.FAILURE)
else:
self._update_result(engine, states.PENDING)
finally:
self._task.unbind('update_progress', self._update_progress)
self._force_state(engine, states.REVERTED, 1.0)
self._force_state(engine, states.PENDING, 0.0)

17
taskflow/task.py
View File

@@ -18,11 +18,15 @@
# under the License.
import abc
import logging
import six
from taskflow.utils import misc
from taskflow.utils import reflection
LOG = logging.getLogger(__name__)
def _save_as_to_mapping(save_as):
"""Convert save_as to mapping name => index
@@ -118,8 +122,7 @@ class BaseTask(object):
# can be useful in resuming older versions of tasks. Standard
# major, minor version semantics apply.
self.version = (1, 0)
# List of callback functions to invoke when progress updated.
self._on_update_progress_notify = []
# Map of events => callback functions to invoke on task events.
self._events_listeners = {}
@property
@@ -159,6 +162,12 @@ class BaseTask(object):
:param progress: task progress float value between 0 and 1
:param kwargs: task specific progress information
"""
if progress > 1.0:
LOG.warn("Progress must be <= 1.0, clamping to upper bound")
progress = 1.0
if progress < 0.0:
LOG.warn("Progress must be >= 0.0, clamping to lower bound")
progress = 0.0
self._trigger('update_progress', progress, **kwargs)
def _trigger(self, event, *args, **kwargs):
@@ -166,7 +175,11 @@ class BaseTask(object):
if event in self._events_listeners:
for handler in self._events_listeners[event]:
event_data = self._events_listeners[event][handler]
try:
handler(self, event_data, *args, **kwargs)
except Exception:
LOG.exception("Failed calling `%s` on event '%s'",
reflection.get_callable_name(handler), event)
def bind(self, event, handler, **kwargs):
"""Attach a handler to an event for the task.

2
taskflow/tests/unit/test_action_engine.py
View File

@@ -120,7 +120,7 @@ class AutoSuspendingTask(TestTask):
engine.suspend()
return result
def revert(self, egnine, result):
def revert(self, engine, result):
super(AutoSuspendingTask, self).revert(**{'result': result})

126
taskflow/tests/unit/test_progress.py Normal file
View File

@@ -0,0 +1,126 @@
# -*- 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
from taskflow import task
from taskflow import test
from taskflow.engines.action_engine import engine as eng
from taskflow.patterns import linear_flow as lf
from taskflow.persistence.backends import impl_memory
from taskflow.utils import persistence_utils as p_utils
class ProgressTask(task.Task):
def __init__(self, name, segments):
super(ProgressTask, self).__init__(name=name)
self._segments = segments
def execute(self):
if self._segments <= 0:
return
for i in range(1, self._segments):
progress = float(i) / self._segments
self.update_progress(progress)
class TestProgress(test.TestCase):
def _make_engine(self, flow):
e = eng.SingleThreadedActionEngine(flow)
e.compile()
return e
def tearDown(self):
super(TestProgress, self).tearDown()
with contextlib.closing(impl_memory.MemoryBackend({})) as be:
with contextlib.closing(be.get_connection()) as conn:
conn.clear_all()
def test_sanity_progress(self):
fired_events = []
def notify_me(task, event_data, progress):
fired_events.append(progress)
ev_count = 5
t = ProgressTask("test", ev_count)
t.bind('update_progress', notify_me)
flo = lf.Flow("test")
flo.add(t)
e = self._make_engine(flo)
e.run()
self.assertEquals(ev_count + 1, len(fired_events))
self.assertEquals(1.0, fired_events[-1])
self.assertEquals(0.0, fired_events[0])
def test_no_segments_progress(self):
fired_events = []
def notify_me(task, event_data, progress):
fired_events.append(progress)
t = ProgressTask("test", 0)
t.bind('update_progress', notify_me)
flo = lf.Flow("test")
flo.add(t)
e = self._make_engine(flo)
e.run()
# 0.0 and 1.0 should be automatically fired
self.assertEquals(2, len(fired_events))
self.assertEquals(1.0, fired_events[-1])
self.assertEquals(0.0, fired_events[0])
def test_storage_progress(self):
with contextlib.closing(impl_memory.MemoryBackend({})) as be:
flo = lf.Flow("test")
flo.add(ProgressTask("test", 3))
b, fd = p_utils.temporary_flow_detail(be)
e = eng.SingleThreadedActionEngine(flo,
book=b, flow_detail=fd,
backend=be)
e.run()
t_uuid = e.storage.get_uuid_by_name("test")
end_progress = e.storage.get_task_progress(t_uuid)
self.assertEquals(1.0, end_progress)
td = fd.find(t_uuid)
self.assertEquals({'progress': 1.0}, td.meta)
def test_dual_storage_progress(self):
fired_events = []
def notify_me(task, event_data, progress):
fired_events.append(progress)
with contextlib.closing(impl_memory.MemoryBackend({})) as be:
t = ProgressTask("test", 5)
t.bind('update_progress', notify_me)
flo = lf.Flow("test")
flo.add(t)
b, fd = p_utils.temporary_flow_detail(be)
e = eng.SingleThreadedActionEngine(flo,
book=b, flow_detail=fd,
backend=be)
e.run()
t_uuid = e.storage.get_uuid_by_name("test")
end_progress = e.storage.get_task_progress(t_uuid)
self.assertEquals(1.0, end_progress)
td = fd.find(t_uuid)
self.assertEquals({'progress': 1.0}, td.meta)
self.assertEquals(6, len(fired_events))