Files
deb-python-taskflow/taskflow/examples/delayed_return.py
Joshua Harlow 58f27fcd2d Remove direct usage of the deprecated notifier 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: Icc389e61613bc78e64083f0086f6f23aabd243d1
2014-10-19 19:55:41 -07:00

90 lines
2.8 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2014 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
import os
import sys
from concurrent import futures
logging.basicConfig(level=logging.ERROR)
self_dir = os.path.abspath(os.path.dirname(__file__))
top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__),
os.pardir,
os.pardir))
sys.path.insert(0, top_dir)
sys.path.insert(0, self_dir)
# INTRO: in this example linear_flow we will attach a listener to an engine
# and delay the return from a function until after the result of a task has
# occurred in that engine. The engine will continue running (in the background)
# while the function will have returned.
import taskflow.engines
from taskflow.listeners import base
from taskflow.patterns import linear_flow as lf
from taskflow import states
from taskflow import task
from taskflow.types import notifier
class PokeFutureListener(base.ListenerBase):
def __init__(self, engine, future, task_name):
super(PokeFutureListener, self).__init__(
engine,
task_listen_for=(notifier.Notifier.ANY,),
flow_listen_for=[])
self._future = future
self._task_name = task_name
def _task_receiver(self, state, details):
if state in (states.SUCCESS, states.FAILURE):
if details.get('task_name') == self._task_name:
if state == states.SUCCESS:
self._future.set_result(details['result'])
else:
failure = details['result']
self._future.set_exception(failure.exception)
class Hi(task.Task):
def execute(self):
# raise IOError("I broken")
return 'hi'
class Bye(task.Task):
def execute(self):
return 'bye'
def return_from_flow(pool):
wf = lf.Flow("root").add(Hi("hi"), Bye("bye"))
eng = taskflow.engines.load(wf, engine='serial')
f = futures.Future()
watcher = PokeFutureListener(eng, f, 'hi')
watcher.register()
pool.submit(eng.run)
return (eng, f.result())
with futures.ThreadPoolExecutor(1) as pool:
engine, hi_result = return_from_flow(pool)
print(hi_result)
print(engine.storage.get_flow_state())