38a9908be4
Make decorator code lean and mean by employing FunctorTask to implement them. This results in: - making everything we call 'task' to provide same interface; - encouraging distinction between task classes and task instances; - code becoming simpler. Implements: blueprint refactor-decorators Change-Id: I43f4ae2db2b7a20f294e2f2d91d53e151a60b139
84 lines
2.5 KiB
Python
84 lines
2.5 KiB
Python
# -*- coding: utf-8 -*-
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (C) 2012-2013 Yahoo! Inc. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import functools
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from taskflow import functor_task
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from taskflow import utils
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def wraps(fn):
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"""This will not be needed in python 3.2 or greater which already has this
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built-in to its functools.wraps method.
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"""
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def wrapper(f):
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f = functools.wraps(fn)(f)
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f.__wrapped__ = getattr(fn, '__wrapped__', fn)
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return f
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return wrapper
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def locked(f):
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@wraps(f)
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def wrapper(self, *args, **kwargs):
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with self._lock:
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return f(self, *args, **kwargs)
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return wrapper
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def _original_function(fun):
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"""Get original function from static or class method"""
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if isinstance(fun, staticmethod):
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return fun.__get__(object())
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elif isinstance(fun, classmethod):
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return fun.__get__(object()).im_func
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return fun
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def task(*args, **kwargs):
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"""Decorates a given function so that it can be used as a task"""
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def decorator(f):
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def task_factory(execute_with, **factory_kwargs):
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merged = kwargs.copy()
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merged.update(factory_kwargs)
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# NOTE(imelnikov): we can't capture f here because for
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# bound methods and bound class methods the object it
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# is bound to is yet unknown at the moment
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return functor_task.FunctorTask(execute_with, **merged)
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w_f = _original_function(f)
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setattr(w_f, utils.TASK_FACTORY_ATTRIBUTE, task_factory)
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return f
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# This is needed to handle when the decorator has args or the decorator
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# doesn't have args, python is rather weird here...
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if kwargs:
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if args:
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raise TypeError('task decorator takes 0 positional arguments,'
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'%s given' % len(args))
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return decorator
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else:
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if len(args) == 1:
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return decorator(args[0])
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else:
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return decorator
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