105 lines
3.0 KiB
Python
105 lines
3.0 KiB
Python
# -*- coding: utf-8 -*-
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (C) 2012 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 collections
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import functools
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import inspect
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# These arguments are ones that we will skip when parsing for requirements
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# for a function to operate (when used as a task).
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AUTO_ARGS = ('self', 'context',)
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def _take_arg(a):
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if a in AUTO_ARGS:
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return False
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# In certain decorator cases it seems like we get the function to be
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# decorated as an argument, we don't want to take that as a real argument.
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if isinstance(a, collections.Callable):
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return False
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return True
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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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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 requires(*args, **kwargs):
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def decorator(f):
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if not hasattr(f, 'requires'):
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f.requires = set()
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if kwargs.pop('auto_extract', True):
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inspect_what = f
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if hasattr(f, '__wrapped__'):
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inspect_what = f.__wrapped__
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f_args = inspect.getargspec(inspect_what).args
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f.requires.update([a for a in f_args if _take_arg(a)])
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f.requires.update([a for a in args if _take_arg(a)])
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@wraps(f)
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def wrapper(*args, **kwargs):
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return f(*args, **kwargs)
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return wrapper
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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 or not args:
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return decorator
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else:
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if isinstance(args[0], collections.Callable):
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return decorator(args[0])
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else:
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return decorator
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def provides(*args, **kwargs):
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def decorator(f):
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if not hasattr(f, 'provides'):
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f.provides = set()
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f.provides.update([a for a in args if _take_arg(a)])
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@wraps(f)
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def wrapper(*args, **kwargs):
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return f(*args, **kwargs)
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return wrapper
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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 or not args:
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return decorator
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else:
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if isinstance(args[0], collections.Callable):
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return decorator(args[0])
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else:
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return decorator
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