openstack/taskflow
Code Issues Proposed changes

Use the notifier type in the task class/module directly

Browse Source 
Instead of having code that is some what like the notifier
code we already have, but is duplicated and is slightly different
in the task class just move the code that was in the task class (and
doing similar actions) to instead now use a notifier that is directly
contained in the task base class for internal task triggering of
internal task events.

Breaking change: alters the capabilities of the task to process
notifications itself, most actions now must go through the task
notifier property and instead use that (update_progress still exists
as a common utility method, since it's likely the most common type
of notification that will be used).

Removes the following methods from task base class (as they are
no longer needed with a notifier attribute):

- trigger (replaced with notifier.notify)
- autobind (removed, not replaced, can be created by the user
            of taskflow in a simple manner, without requiring
            functionality in taskflow)
- bind (replaced with notifier.register)
- unbind (replaced with notifier.unregister)
- listeners_iter (replaced with notifier.listeners_iter)

Due to this change we can now also correctly proxy back events from
remote tasks to the engine for correct proxying back to the original
task.

Fixes bug 1370766

Change-Id: Ic9dfef516d72e6e32e71dda30a1cb3522c9e0be6
This commit is contained in:
Joshua Harlow
2014-12-12 15:57:53 -08:00
committed by Joshua Harlow
parent cdfd8ece61
commit 1f4dd72e6e
17 changed files with 492 additions and 364 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
taskflow/engines/worker_based/server.py
View File

@@ -22,6 +22,7 @@ from taskflow.engines.worker_based import protocol as pr
from taskflow.engines.worker_based import proxy
from taskflow import logging
from taskflow.types import failure as ft
from taskflow.types import notifier as nt
from taskflow.utils import misc
LOG = logging.getLogger(__name__)
@@ -73,18 +74,23 @@ class Server(object):
All `failure.Failure` objects that have been converted to dict on the
remote side will now converted back to `failure.Failure` objects.
"""
action_args = dict(arguments=arguments, task_name=task_name)
# These arguments will eventually be given to the task executor
# so they need to be in a format it will accept (and using keyword
# argument names that it accepts)...
arguments = {
'arguments': arguments,
}
if result is not None:
data_type, data = result
if data_type == 'failure':
action_args['result'] = ft.Failure.from_dict(data)
arguments['result'] = ft.Failure.from_dict(data)
else:
action_args['result'] = data
arguments['result'] = data
if failures is not None:
action_args['failures'] = {}
arguments['failures'] = {}
for key, data in six.iteritems(failures):
action_args['failures'][key] = ft.Failure.from_dict(data)
return task_cls, action, action_args
arguments['failures'][key] = ft.Failure.from_dict(data)
return (task_cls, task_name, action, arguments)
@staticmethod
def _parse_message(message):
@@ -122,14 +128,13 @@ class Server(object):
exc_info=True)
return published
def _on_update_progress(self, reply_to, task_uuid, task, event_data,
progress):
"""Send task update progress notification."""
def _on_event(self, reply_to, task_uuid, event_type, details):
"""Send out a task event notification."""
# NOTE(harlowja): the executor that will trigger this using the
# task notification/listener mechanism will handle logging if this
# fails, so thats why capture is 'False' is used here.
self._reply(False, reply_to, task_uuid, pr.PROGRESS,
event_data=event_data, progress=progress)
self._reply(False, reply_to, task_uuid, pr.EVENT,
event_type=event_type, details=details)
def _process_notify(self, notify, message):
"""Process notify message and reply back."""
@@ -165,18 +170,15 @@ class Server(object):
message.delivery_tag, exc_info=True)
return
else:
# prepare task progress callback
progress_callback = functools.partial(self._on_update_progress,
reply_to, task_uuid)
# prepare reply callback
reply_callback = functools.partial(self._reply, True, reply_to,
task_uuid)
# parse request to get task name, action and action arguments
try:
task_cls, action, action_args = self._parse_request(**request)
action_args.update(task_uuid=task_uuid,
progress_callback=progress_callback)
bundle = self._parse_request(**request)
task_cls, task_name, action, arguments = bundle
arguments['task_uuid'] = task_uuid
except ValueError:
with misc.capture_failure() as failure:
LOG.warn("Failed to parse request contents from message %r",
@@ -206,12 +208,36 @@ class Server(object):
reply_callback(result=failure.to_dict())
return
else:
if not reply_callback(state=pr.RUNNING):
return
try:
task = endpoint.generate(name=task_name)
except Exception:
with misc.capture_failure() as failure:
LOG.warn("The '%s' task '%s' generation for request"
" message %r failed", endpoint, action,
message.delivery_tag, exc_info=True)
reply_callback(result=failure.to_dict())
return
else:
if not reply_callback(state=pr.RUNNING):
return
# perform task action
# associate *any* events this task emits with a proxy that will
# emit them back to the engine... for handling at the engine side
# of things...
if task.notifier.can_be_registered(nt.Notifier.ANY):
task.notifier.register(nt.Notifier.ANY,
functools.partial(self._on_event,
reply_to, task_uuid))
elif isinstance(task.notifier, nt.RestrictedNotifier):
# only proxy the allowable events then...
for event_type in task.notifier.events_iter():
task.notifier.register(event_type,
functools.partial(self._on_event,
reply_to, task_uuid))
# perform the task action
try:
result = handler(**action_args)
result = handler(task, **arguments)
except Exception:
with misc.capture_failure() as failure:
LOG.warn("The '%s' endpoint '%s' execution for request"