246 lines
9.1 KiB
Python
246 lines
9.1 KiB
Python
import functools
|
|
|
|
from . import six
|
|
|
|
class _WrapperOverrideMethods(object):
|
|
|
|
@property
|
|
def __module__(self):
|
|
return self._self_wrapped.__module__
|
|
|
|
@__module__.setter
|
|
def __module__(self, value):
|
|
self._self_wrapped.__module__ = value
|
|
|
|
@property
|
|
def __doc__(self):
|
|
return self._self_wrapped.__doc__
|
|
|
|
@__doc__.setter
|
|
def __doc__(self, value):
|
|
self._self_wrapped.__doc__ = value
|
|
|
|
class _WrapperBaseMetaType(type):
|
|
def __new__(cls, name, bases, dictionary):
|
|
# We use properties to override the values of __module__ and
|
|
# __doc__. If we add these in _WrapperBase, the derived class
|
|
# __dict__ will still be setup to have string variants of these
|
|
# attributes and the rules of descriptors means that they
|
|
# appear to take precedence over the properties in the base
|
|
# class. To avoid that, we copy the properties into the derived
|
|
# class type itself via a meta class. In that way the
|
|
# properties will always take precedence.
|
|
|
|
dictionary.update(vars(_WrapperOverrideMethods))
|
|
return type.__new__(cls, name, bases, dictionary)
|
|
|
|
class _WrapperBase(six.with_metaclass(_WrapperBaseMetaType)):
|
|
|
|
def __init__(self, wrapped, wrapper, target=None):
|
|
self._self_wrapped = wrapped
|
|
self._self_wrapper = wrapper
|
|
|
|
# Python 3.2+ has the __wrapped__ attribute which is meant to
|
|
# hold a reference to the inner most wrapped object when there
|
|
# are multiple decorators. We handle __wrapped__ and also
|
|
# duplicate that functionality for Python 2, although it will
|
|
# only go as far as what is below our own wrappers when there is
|
|
# more than one for Python 2.
|
|
|
|
if target is None:
|
|
try:
|
|
self._self_target = wrapped.__wrapped__
|
|
except AttributeError:
|
|
self._self_target = wrapped
|
|
else:
|
|
self._self_target = target
|
|
|
|
# Python 3.2+ has the __qualname__ attribute, but it does not
|
|
# allow it to be overridden using a property and it must instead
|
|
# be an actual string object instead.
|
|
|
|
try:
|
|
if target is None:
|
|
self.__qualname__ = wrapped.__qualname__
|
|
else:
|
|
self.__qualname__ = target.__qualname__
|
|
except AttributeError:
|
|
pass
|
|
|
|
# Although __name__ can be overridden with a property in all
|
|
# Python versions, updating it writes it back to an internal C
|
|
# structure which can be accessed at C code level, so not sure
|
|
# if overriding it as a property is sufficient in all cases.
|
|
|
|
try:
|
|
if target is None:
|
|
self. __name__ = wrapped.__name__
|
|
else:
|
|
self.__name__ = target.__name__
|
|
except AttributeError:
|
|
pass
|
|
|
|
def __setattr__(self, name, value):
|
|
if name.startswith('_self_'):
|
|
object.__setattr__(self, name, value)
|
|
elif name in ('__name__', '__qualname__'):
|
|
object.__setattr__(self, name, value)
|
|
setattr(self._self_wrapped, name, value)
|
|
else:
|
|
setattr(self._self_wrapped, name, value)
|
|
|
|
def __getattr__(self, name):
|
|
return getattr(self._self_wrapped, name)
|
|
|
|
@property
|
|
def __class__(self):
|
|
return self._self_wrapped.__class__
|
|
|
|
@__class__.setter
|
|
def __class__(self, value):
|
|
self._self_wrapped.__class__ = value
|
|
|
|
@property
|
|
def __annotations__(self):
|
|
return self._self_wrapped.__anotations__
|
|
|
|
@__annotations__.setter
|
|
def __annotations__(self, value):
|
|
self._self_wrapped.__annotations__ = value
|
|
|
|
@property
|
|
def __wrapped__(self):
|
|
return self._self_target
|
|
|
|
@__wrapped__.setter
|
|
def __wrapped__(self, value):
|
|
self._self_wrapped.__wrapped__ = value
|
|
|
|
def __dir__(self):
|
|
return dir(self._self_wrapped)
|
|
|
|
def __eq__(self, other):
|
|
return self._self_target == other
|
|
|
|
def __ne__(self, other):
|
|
result = self.__eq__(other)
|
|
if result is NotImplemented:
|
|
return result
|
|
return not result
|
|
|
|
def __hash__(self):
|
|
return hash(self._self_target)
|
|
|
|
def __repr__(self):
|
|
return '<%s for %s>' % (type(self).__name__, str(self._self_target))
|
|
|
|
def __enter__(self):
|
|
return self._self_wrapped.__enter__()
|
|
|
|
def __exit__(self, *args, **kwargs):
|
|
return self._self_wrapped.__exit__(*args, **kwargs)
|
|
|
|
def __iter__(self):
|
|
return iter(self._self_wrapped)
|
|
|
|
class _BoundFunctionWrapper(_WrapperBase):
|
|
|
|
def __init__(self, wrapped, instance, wrapper, target=None, params={}):
|
|
super(_BoundFunctionWrapper, self).__init__(wrapped, wrapper, target)
|
|
self._self_instance = instance
|
|
self._self_params = params
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
return self._self_wrapper(self._self_wrapped, self._self_instance,
|
|
args, kwargs, **self._self_params)
|
|
|
|
class _BoundMethodWrapper(_WrapperBase):
|
|
|
|
def __init__(self, wrapped, instance, wrapper, target=None, params={}):
|
|
super(_BoundMethodWrapper, self).__init__(wrapped, wrapper, target)
|
|
self._self_instance = instance
|
|
self._self_params = params
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
if self._self_instance is None:
|
|
# This situation can occur where someone is calling the
|
|
# instancemethod via the class type and passing the instance
|
|
# as the first argument. We need to shift the args before
|
|
# making the call to the wrapper and effectively bind the
|
|
# instance to the wrapped function using a partial so the
|
|
# wrapper doesn't see anything as being different.
|
|
|
|
instance, args = args[0], args[1:]
|
|
wrapped = functools.partial(self._self_wrapped, instance)
|
|
return self._self_wrapper(wrapped, instance, args, kwargs,
|
|
**self._self_params)
|
|
|
|
return self._self_wrapper(self._self_wrapped, self._self_instance,
|
|
args, kwargs, **self._self_params)
|
|
|
|
class FunctionWrapper(_WrapperBase):
|
|
|
|
def __init__(self, wrapped, wrapper, target=None, params={}):
|
|
super(FunctionWrapper, self).__init__(wrapped, wrapper, target)
|
|
self._self_params = params
|
|
|
|
# We need to do special fixups on the args in the case of an
|
|
# instancemethod where called via the class and the instance is
|
|
# passed explicitly as the first argument. Defer to the
|
|
# _BoundMethodWrapper for these specific fixups when we believe
|
|
# it is likely an instancemethod. That is, anytime it isn't
|
|
# classmethod or staticmethod.
|
|
#
|
|
# Note that there isn't strictly a fool proof method of knowing
|
|
# which is occuring because if a decorator using this code wraps
|
|
# other decorators and they are poorly implemented they can
|
|
# throw away important information needed to determine it. Some
|
|
# ways that it could be determined in Python 2 are also not
|
|
# possible in Python 3 due to the concept of unbound methods
|
|
# being done away with.
|
|
#
|
|
# Anyway, the best we can do is look at the original type of the
|
|
# object which was wrapped prior to any binding being done and
|
|
# see if it is an instance of classmethod or staticmethod. In
|
|
# the case where other decorators are between us and them, if
|
|
# they do not propagate the __class__ attribute so that the
|
|
# isinstance() checks works, then likely this will do the wrong
|
|
# thing where classmethod and staticmethod are used.
|
|
#
|
|
# Since it is likely to be very rare that anyone even puts
|
|
# decorators around classmethod and staticmethod, likelihood of
|
|
# that being an issue is very small, so we accept it and suggest
|
|
# that those other decorators be fixed. It is also only an issue
|
|
# if a decorator wants to actually do things with the arguments.
|
|
# For the case of a classmethod the class wouldn't be known
|
|
# anyway, as it is only added in by the classmethod decorator
|
|
# later.
|
|
|
|
if isinstance(self._self_wrapped, (classmethod, staticmethod)):
|
|
self._self_wrapper_type = _BoundFunctionWrapper
|
|
else:
|
|
self._self_wrapper_type = _BoundMethodWrapper
|
|
|
|
def __get__(self, instance, owner):
|
|
descriptor = self._self_wrapped.__get__(instance, owner)
|
|
|
|
return self._self_wrapper_type(descriptor, instance,
|
|
self._self_wrapper, self._self_target, self._self_params)
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
# This is invoked when the wrapped function is being called as a
|
|
# normal function and is not bound to a class as an instance
|
|
# method. This is also invoked in the case where the wrapped
|
|
# function was a method, but this wrapper was in turn wrapped
|
|
# using the staticmethod decorator.
|
|
|
|
return self._self_wrapper(self._self_wrapped, None, args,
|
|
kwargs, **self._self_params)
|
|
|
|
try:
|
|
from ._wrappers import FunctionWrapper as C_FunctionWrapper
|
|
PY_FunctionWrapper = FunctionWrapper
|
|
FunctionWrapper = C_FunctionWrapper
|
|
except ImportError:
|
|
pass
|