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patches.py
98 lines
| 3.7 KiB
| text/x-python
|
PythonLexer
r1 | # -*- coding: utf-8 -*- | |||
r2487 | # Copyright (C) 2016-2018 RhodeCode GmbH | |||
r1 | # | |||
# This program is free software: you can redistribute it and/or modify | ||||
# it under the terms of the GNU Affero General Public License, version 3 | ||||
# (only), as published by the Free Software Foundation. | ||||
# | ||||
# This program is distributed in the hope that it will be useful, | ||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of | ||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||||
# GNU General Public License for more details. | ||||
# | ||||
# You should have received a copy of the GNU Affero General Public License | ||||
# along with this program. If not, see <http://www.gnu.org/licenses/>. | ||||
# | ||||
# This program is dual-licensed. If you wish to learn more about the | ||||
# RhodeCode Enterprise Edition, including its added features, Support services, | ||||
# and proprietary license terms, please see https://rhodecode.com/licenses/ | ||||
""" | ||||
Compatibility patches. | ||||
Please keep the following principles in mind: | ||||
* Keep imports local, so that importing this module does not cause too many | ||||
side effects by itself. | ||||
* Try to make patches idempotent, calling them multiple times should not do | ||||
harm. If that is not possible, ensure that the second call explodes. | ||||
""" | ||||
def inspect_getargspec(): | ||||
""" | ||||
r2351 | Pyramid rely on inspect.getargspec to lookup the signature of | |||
r1 | view functions. This is not compatible with cython, therefore we replace | |||
getargspec with a custom version. | ||||
Code is inspired by the inspect module from Python-3.4 | ||||
""" | ||||
import inspect | ||||
def _isCython(func): | ||||
""" | ||||
Private helper that checks if a function is a cython function. | ||||
""" | ||||
return func.__class__.__name__ == 'cython_function_or_method' | ||||
def unwrap(func): | ||||
""" | ||||
Get the object wrapped by *func*. | ||||
Follows the chain of :attr:`__wrapped__` attributes returning the last | ||||
object in the chain. | ||||
*stop* is an optional callback accepting an object in the wrapper chain | ||||
as its sole argument that allows the unwrapping to be terminated early | ||||
if the callback returns a true value. If the callback never returns a | ||||
true value, the last object in the chain is returned as usual. For | ||||
example, :func:`signature` uses this to stop unwrapping if any object | ||||
in the chain has a ``__signature__`` attribute defined. | ||||
:exc:`ValueError` is raised if a cycle is encountered. | ||||
""" | ||||
f = func # remember the original func for error reporting | ||||
memo = {id(f)} # Memoise by id to tolerate non-hashable objects | ||||
while hasattr(func, '__wrapped__'): | ||||
func = func.__wrapped__ | ||||
id_func = id(func) | ||||
if id_func in memo: | ||||
raise ValueError('wrapper loop when unwrapping {!r}'.format(f)) | ||||
memo.add(id_func) | ||||
return func | ||||
def custom_getargspec(func): | ||||
""" | ||||
Get the names and default values of a function's arguments. | ||||
A tuple of four things is returned: (args, varargs, varkw, defaults). | ||||
'args' is a list of the argument names (it may contain nested lists). | ||||
'varargs' and 'varkw' are the names of the * and ** arguments or None. | ||||
'defaults' is an n-tuple of the default values of the last n arguments. | ||||
""" | ||||
func = unwrap(func) | ||||
if inspect.ismethod(func): | ||||
func = func.im_func | ||||
if not inspect.isfunction(func): | ||||
if not _isCython(func): | ||||
raise TypeError('{!r} is not a Python or Cython function' | ||||
.format(func)) | ||||
args, varargs, varkw = inspect.getargs(func.func_code) | ||||
return inspect.ArgSpec(args, varargs, varkw, func.func_defaults) | ||||
inspect.getargspec = custom_getargspec | ||||