Source code for taskflow.types.timing

# -*- 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
#    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 threading

[docs]class Timeout(object): """An object which represents a timeout. This object has the ability to be interrupted before the actual timeout is reached. """ def __init__(self, value, event_factory=threading.Event): if value < 0: raise ValueError("Timeout value must be greater or" " equal to zero and not '%s'" % (value)) self._value = value self._event = event_factory() @property def value(self): """Immutable value of the internally used timeout.""" return self._value
[docs] def interrupt(self): """Forcefully set the timeout (releases any waiters).""" self._event.set()
[docs] def is_stopped(self): """Returns if the timeout has been interrupted.""" return self._event.is_set()
[docs] def wait(self): """Block current thread (up to timeout) and wait until interrupted.""" self._event.wait(self._value)
[docs] def reset(self): """Reset so that interruption (and waiting) can happen again.""" self._event.clear()
[docs]def convert_to_timeout(value=None, default_value=None, event_factory=threading.Event): """Converts a given value to a timeout instance (and returns it). Does nothing if the value provided is already a timeout instance. """ if value is None: value = default_value if isinstance(value, (int, float, str)): return Timeout(float(value), event_factory=event_factory) elif isinstance(value, Timeout): return value else: raise ValueError("Invalid timeout literal '%s'" % (value))