You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
901 lines
32 KiB
901 lines
32 KiB
import os
|
|
import sys
|
|
import functools
|
|
import operator
|
|
import weakref
|
|
import inspect
|
|
|
|
PY2 = sys.version_info[0] == 2
|
|
PY3 = sys.version_info[0] == 3
|
|
|
|
if PY3:
|
|
string_types = str,
|
|
else:
|
|
string_types = basestring,
|
|
|
|
def with_metaclass(meta, *bases):
|
|
"""Create a base class with a metaclass."""
|
|
return meta("NewBase", bases, {})
|
|
|
|
class _ObjectProxyMethods(object):
|
|
|
|
# We use properties to override the values of __module__ and
|
|
# __doc__. If we add these in ObjectProxy, 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.
|
|
|
|
@property
|
|
def __module__(self):
|
|
return self.__wrapped__.__module__
|
|
|
|
@__module__.setter
|
|
def __module__(self, value):
|
|
self.__wrapped__.__module__ = value
|
|
|
|
@property
|
|
def __doc__(self):
|
|
return self.__wrapped__.__doc__
|
|
|
|
@__doc__.setter
|
|
def __doc__(self, value):
|
|
self.__wrapped__.__doc__ = value
|
|
|
|
# We similar use a property for __dict__. We need __dict__ to be
|
|
# explicit to ensure that vars() works as expected.
|
|
|
|
@property
|
|
def __dict__(self):
|
|
return self.__wrapped__.__dict__
|
|
|
|
# Need to also propagate the special __weakref__ attribute for case
|
|
# where decorating classes which will define this. If do not define
|
|
# it and use a function like inspect.getmembers() on a decorator
|
|
# class it will fail. This can't be in the derived classes.
|
|
|
|
@property
|
|
def __weakref__(self):
|
|
return self.__wrapped__.__weakref__
|
|
|
|
class _ObjectProxyMetaType(type):
|
|
def __new__(cls, name, bases, dictionary):
|
|
# Copy our special properties into the class so that they
|
|
# always take precedence over attributes of the same name added
|
|
# during construction of a derived class. This is to save
|
|
# duplicating the implementation for them in all derived classes.
|
|
|
|
dictionary.update(vars(_ObjectProxyMethods))
|
|
|
|
return type.__new__(cls, name, bases, dictionary)
|
|
|
|
class ObjectProxy(with_metaclass(_ObjectProxyMetaType)):
|
|
|
|
__slots__ = '__wrapped__'
|
|
|
|
def __init__(self, wrapped):
|
|
object.__setattr__(self, '__wrapped__', wrapped)
|
|
|
|
# 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:
|
|
object.__setattr__(self, '__qualname__', wrapped.__qualname__)
|
|
except AttributeError:
|
|
pass
|
|
|
|
@property
|
|
def __name__(self):
|
|
return self.__wrapped__.__name__
|
|
|
|
@__name__.setter
|
|
def __name__(self, value):
|
|
self.__wrapped__.__name__ = value
|
|
|
|
@property
|
|
def __class__(self):
|
|
return self.__wrapped__.__class__
|
|
|
|
@__class__.setter
|
|
def __class__(self, value):
|
|
self.__wrapped__.__class__ = value
|
|
|
|
@property
|
|
def __annotations__(self):
|
|
return self.__wrapped__.__anotations__
|
|
|
|
@__annotations__.setter
|
|
def __annotations__(self, value):
|
|
self.__wrapped__.__annotations__ = value
|
|
|
|
def __dir__(self):
|
|
return dir(self.__wrapped__)
|
|
|
|
def __str__(self):
|
|
return str(self.__wrapped__)
|
|
|
|
if PY3:
|
|
def __bytes__(self):
|
|
return bytes(self.__wrapped__)
|
|
|
|
def __repr__(self):
|
|
return '<%s at 0x%x for %s at 0x%x>' % (
|
|
type(self).__name__, id(self),
|
|
type(self.__wrapped__).__name__,
|
|
id(self.__wrapped__))
|
|
|
|
def __reversed__(self):
|
|
return reversed(self.__wrapped__)
|
|
|
|
if PY3:
|
|
def __round__(self):
|
|
return round(self.__wrapped__)
|
|
|
|
def __lt__(self, other):
|
|
return self.__wrapped__ < other
|
|
|
|
def __le__(self, other):
|
|
return self.__wrapped__ <= other
|
|
|
|
def __eq__(self, other):
|
|
return self.__wrapped__ == other
|
|
|
|
def __ne__(self, other):
|
|
return self.__wrapped__ != other
|
|
|
|
def __gt__(self, other):
|
|
return self.__wrapped__ > other
|
|
|
|
def __ge__(self, other):
|
|
return self.__wrapped__ >= other
|
|
|
|
def __hash__(self):
|
|
return hash(self.__wrapped__)
|
|
|
|
def __nonzero__(self):
|
|
return bool(self.__wrapped__)
|
|
|
|
def __bool__(self):
|
|
return bool(self.__wrapped__)
|
|
|
|
def __setattr__(self, name, value):
|
|
if name.startswith('_self_'):
|
|
object.__setattr__(self, name, value)
|
|
|
|
elif name == '__wrapped__':
|
|
object.__setattr__(self, name, value)
|
|
try:
|
|
object.__delattr__(self, '__qualname__')
|
|
except AttributeError:
|
|
pass
|
|
try:
|
|
object.__setattr__(self, '__qualname__', value.__qualname__)
|
|
except AttributeError:
|
|
pass
|
|
|
|
elif name == '__qualname__':
|
|
setattr(self.__wrapped__, name, value)
|
|
object.__setattr__(self, name, value)
|
|
|
|
elif hasattr(type(self), name):
|
|
object.__setattr__(self, name, value)
|
|
|
|
else:
|
|
setattr(self.__wrapped__, name, value)
|
|
|
|
def __getattr__(self, name):
|
|
# If we are being to lookup '__wrapped__' then the
|
|
# '__init__()' method cannot have been called.
|
|
|
|
if name == '__wrapped__':
|
|
raise ValueError('wrapper has not been initialised')
|
|
|
|
return getattr(self.__wrapped__, name)
|
|
|
|
def __delattr__(self, name):
|
|
if name.startswith('_self_'):
|
|
object.__delattr__(self, name)
|
|
|
|
elif name == '__wrapped__':
|
|
raise TypeError('__wrapped__ must be an object')
|
|
|
|
elif name == '__qualname__':
|
|
object.__delattr__(self, name)
|
|
delattr(self.__wrapped__, name)
|
|
|
|
elif hasattr(type(self), name):
|
|
object.__delattr__(self, name)
|
|
|
|
else:
|
|
delattr(self.__wrapped__, name)
|
|
|
|
def __add__(self, other):
|
|
return self.__wrapped__ + other
|
|
|
|
def __sub__(self, other):
|
|
return self.__wrapped__ - other
|
|
|
|
def __mul__(self, other):
|
|
return self.__wrapped__ * other
|
|
|
|
def __div__(self, other):
|
|
return operator.div(self.__wrapped__, other)
|
|
|
|
def __truediv__(self, other):
|
|
return operator.truediv(self.__wrapped__, other)
|
|
|
|
def __floordiv__(self, other):
|
|
return self.__wrapped__ // other
|
|
|
|
def __mod__(self, other):
|
|
return self.__wrapped__ % other
|
|
|
|
def __divmod__(self, other):
|
|
return divmod(self.__wrapped__, other)
|
|
|
|
def __pow__(self, other, *args):
|
|
return pow(self.__wrapped__, other, *args)
|
|
|
|
def __lshift__(self, other):
|
|
return self.__wrapped__ << other
|
|
|
|
def __rshift__(self, other):
|
|
return self.__wrapped__ >> other
|
|
|
|
def __and__(self, other):
|
|
return self.__wrapped__ & other
|
|
|
|
def __xor__(self, other):
|
|
return self.__wrapped__ ^ other
|
|
|
|
def __or__(self, other):
|
|
return self.__wrapped__ | other
|
|
|
|
def __radd__(self, other):
|
|
return other + self.__wrapped__
|
|
|
|
def __rsub__(self, other):
|
|
return other - self.__wrapped__
|
|
|
|
def __rmul__(self, other):
|
|
return other * self.__wrapped__
|
|
|
|
def __rdiv__(self, other):
|
|
return operator.div(other, self.__wrapped__)
|
|
|
|
def __rtruediv__(self, other):
|
|
return operator.truediv(other, self.__wrapped__)
|
|
|
|
def __rfloordiv__(self, other):
|
|
return other // self.__wrapped__
|
|
|
|
def __rmod__(self, other):
|
|
return other % self.__wrapped__
|
|
|
|
def __rdivmod__(self, other):
|
|
return divmod(other, self.__wrapped__)
|
|
|
|
def __rpow__(self, other, *args):
|
|
return pow(other, self.__wrapped__, *args)
|
|
|
|
def __rlshift__(self, other):
|
|
return other << self.__wrapped__
|
|
|
|
def __rrshift__(self, other):
|
|
return other >> self.__wrapped__
|
|
|
|
def __rand__(self, other):
|
|
return other & self.__wrapped__
|
|
|
|
def __rxor__(self, other):
|
|
return other ^ self.__wrapped__
|
|
|
|
def __ror__(self, other):
|
|
return other | self.__wrapped__
|
|
|
|
def __iadd__(self, other):
|
|
self.__wrapped__ += other
|
|
return self
|
|
|
|
def __isub__(self, other):
|
|
self.__wrapped__ -= other
|
|
return self
|
|
|
|
def __imul__(self, other):
|
|
self.__wrapped__ *= other
|
|
return self
|
|
|
|
def __idiv__(self, other):
|
|
self.__wrapped__ = operator.idiv(self.__wrapped__, other)
|
|
return self
|
|
|
|
def __itruediv__(self, other):
|
|
self.__wrapped__ = operator.itruediv(self.__wrapped__, other)
|
|
return self
|
|
|
|
def __ifloordiv__(self, other):
|
|
self.__wrapped__ //= other
|
|
return self
|
|
|
|
def __imod__(self, other):
|
|
self.__wrapped__ %= other
|
|
return self
|
|
|
|
def __ipow__(self, other):
|
|
self.__wrapped__ **= other
|
|
return self
|
|
|
|
def __ilshift__(self, other):
|
|
self.__wrapped__ <<= other
|
|
return self
|
|
|
|
def __irshift__(self, other):
|
|
self.__wrapped__ >>= other
|
|
return self
|
|
|
|
def __iand__(self, other):
|
|
self.__wrapped__ &= other
|
|
return self
|
|
|
|
def __ixor__(self, other):
|
|
self.__wrapped__ ^= other
|
|
return self
|
|
|
|
def __ior__(self, other):
|
|
self.__wrapped__ |= other
|
|
return self
|
|
|
|
def __neg__(self):
|
|
return -self.__wrapped__
|
|
|
|
def __pos__(self):
|
|
return +self.__wrapped__
|
|
|
|
def __abs__(self):
|
|
return abs(self.__wrapped__)
|
|
|
|
def __invert__(self):
|
|
return ~self.__wrapped__
|
|
|
|
def __int__(self):
|
|
return int(self.__wrapped__)
|
|
|
|
def __long__(self):
|
|
return long(self.__wrapped__)
|
|
|
|
def __float__(self):
|
|
return float(self.__wrapped__)
|
|
|
|
def __oct__(self):
|
|
return oct(self.__wrapped__)
|
|
|
|
def __hex__(self):
|
|
return hex(self.__wrapped__)
|
|
|
|
def __index__(self):
|
|
return operator.index(self.__wrapped__)
|
|
|
|
def __len__(self):
|
|
return len(self.__wrapped__)
|
|
|
|
def __contains__(self, value):
|
|
return value in self.__wrapped__
|
|
|
|
def __getitem__(self, key):
|
|
return self.__wrapped__[key]
|
|
|
|
def __setitem__(self, key, value):
|
|
self.__wrapped__[key] = value
|
|
|
|
def __delitem__(self, key):
|
|
del self.__wrapped__[key]
|
|
|
|
def __getslice__(self, i, j):
|
|
return self.__wrapped__[i:j]
|
|
|
|
def __setslice__(self, i, j, value):
|
|
self.__wrapped__[i:j] = value
|
|
|
|
def __delslice__(self, i, j):
|
|
del self.__wrapped__[i:j]
|
|
|
|
def __enter__(self):
|
|
return self.__wrapped__.__enter__()
|
|
|
|
def __exit__(self, *args, **kwargs):
|
|
return self.__wrapped__.__exit__(*args, **kwargs)
|
|
|
|
def __iter__(self):
|
|
return iter(self.__wrapped__)
|
|
|
|
class CallableObjectProxy(ObjectProxy):
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
return self.__wrapped__(*args, **kwargs)
|
|
|
|
class _FunctionWrapperBase(ObjectProxy):
|
|
|
|
__slots__ = ('_self_instance', '_self_wrapper', '_self_enabled',
|
|
'_self_binding', '_self_parent')
|
|
|
|
def __init__(self, wrapped, instance, wrapper, enabled=None,
|
|
binding='function', parent=None):
|
|
|
|
super(_FunctionWrapperBase, self).__init__(wrapped)
|
|
|
|
object.__setattr__(self, '_self_instance', instance)
|
|
object.__setattr__(self, '_self_wrapper', wrapper)
|
|
object.__setattr__(self, '_self_enabled', enabled)
|
|
object.__setattr__(self, '_self_binding', binding)
|
|
object.__setattr__(self, '_self_parent', parent)
|
|
|
|
def __get__(self, instance, owner):
|
|
# This method is actually doing double duty for both unbound and
|
|
# bound derived wrapper classes. It should possibly be broken up
|
|
# and the distinct functionality moved into the derived classes.
|
|
# Can't do that straight away due to some legacy code which is
|
|
# relying on it being here in this base class.
|
|
#
|
|
# The distinguishing attribute which determines whether we are
|
|
# being called in an unbound or bound wrapper is the parent
|
|
# attribute. If binding has never occurred, then the parent will
|
|
# be None.
|
|
#
|
|
# First therefore, is if we are called in an unbound wrapper. In
|
|
# this case we perform the binding.
|
|
#
|
|
# We have one special case to worry about here. This is where we
|
|
# are decorating a nested class. In this case the wrapped class
|
|
# would not have a __get__() method to call. In that case we
|
|
# simply return self.
|
|
#
|
|
# Note that we otherwise still do binding even if instance is
|
|
# None and accessing an unbound instance method from a class.
|
|
# This is because we need to be able to later detect that
|
|
# specific case as we will need to extract the instance from the
|
|
# first argument of those passed in.
|
|
|
|
if self._self_parent is None:
|
|
if not inspect.isclass(self.__wrapped__):
|
|
descriptor = self.__wrapped__.__get__(instance, owner)
|
|
|
|
return self.__bound_function_wrapper__(descriptor, instance,
|
|
self._self_wrapper, self._self_enabled,
|
|
self._self_binding, self)
|
|
|
|
return self
|
|
|
|
# Now we have the case of binding occurring a second time on what
|
|
# was already a bound function. In this case we would usually
|
|
# return ourselves again. This mirrors what Python does.
|
|
#
|
|
# The special case this time is where we were originally bound
|
|
# with an instance of None and we were likely an instance
|
|
# method. In that case we rebind against the original wrapped
|
|
# function from the parent again.
|
|
|
|
if self._self_instance is None and self._self_binding == 'function':
|
|
descriptor = self._self_parent.__wrapped__.__get__(
|
|
instance, owner)
|
|
|
|
return self._self_parent.__bound_function_wrapper__(
|
|
descriptor, instance, self._self_wrapper,
|
|
self._self_enabled, self._self_binding,
|
|
self._self_parent)
|
|
|
|
return self
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
# If enabled has been specified, then evaluate it at this point
|
|
# and if the wrapper is not to be executed, then simply return
|
|
# the bound function rather than a bound wrapper for the bound
|
|
# function. When evaluating enabled, if it is callable we call
|
|
# it, otherwise we evaluate it as a boolean.
|
|
|
|
if self._self_enabled is not None:
|
|
if callable(self._self_enabled):
|
|
if not self._self_enabled():
|
|
return self.__wrapped__(*args, **kwargs)
|
|
elif not self._self_enabled:
|
|
return self.__wrapped__(*args, **kwargs)
|
|
|
|
# This can occur where initial function wrapper was applied to
|
|
# a function that was already bound to an instance. In that case
|
|
# we want to extract the instance from the function and use it.
|
|
|
|
if self._self_binding == 'function':
|
|
if self._self_instance is None:
|
|
instance = getattr(self.__wrapped__, '__self__', None)
|
|
if instance is not None:
|
|
return self._self_wrapper(self.__wrapped__, instance,
|
|
args, kwargs)
|
|
|
|
# This is generally 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.__wrapped__, self._self_instance,
|
|
args, kwargs)
|
|
|
|
class BoundFunctionWrapper(_FunctionWrapperBase):
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
# If enabled has been specified, then evaluate it at this point
|
|
# and if the wrapper is not to be executed, then simply return
|
|
# the bound function rather than a bound wrapper for the bound
|
|
# function. When evaluating enabled, if it is callable we call
|
|
# it, otherwise we evaluate it as a boolean.
|
|
|
|
if self._self_enabled is not None:
|
|
if callable(self._self_enabled):
|
|
if not self._self_enabled():
|
|
return self.__wrapped__(*args, **kwargs)
|
|
elif not self._self_enabled:
|
|
return self.__wrapped__(*args, **kwargs)
|
|
|
|
# We need to do things different depending on whether we are
|
|
# likely wrapping an instance method vs a static method or class
|
|
# method.
|
|
|
|
if self._self_binding == 'function':
|
|
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.
|
|
|
|
if not args:
|
|
raise TypeError('missing 1 required positional argument')
|
|
|
|
instance, args = args[0], args[1:]
|
|
wrapped = functools.partial(self.__wrapped__, instance)
|
|
return self._self_wrapper(wrapped, instance, args, kwargs)
|
|
|
|
return self._self_wrapper(self.__wrapped__, self._self_instance,
|
|
args, kwargs)
|
|
|
|
else:
|
|
# As in this case we would be dealing with a classmethod or
|
|
# staticmethod, then _self_instance will only tell us whether
|
|
# when calling the classmethod or staticmethod they did it via an
|
|
# instance of the class it is bound to and not the case where
|
|
# done by the class type itself. We thus ignore _self_instance
|
|
# and use the __self__ attribute of the bound function instead.
|
|
# For a classmethod, this means instance will be the class type
|
|
# and for a staticmethod it will be None. This is probably the
|
|
# more useful thing we can pass through even though we loose
|
|
# knowledge of whether they were called on the instance vs the
|
|
# class type, as it reflects what they have available in the
|
|
# decoratored function.
|
|
|
|
instance = getattr(self.__wrapped__, '__self__', None)
|
|
|
|
return self._self_wrapper(self.__wrapped__, instance, args,
|
|
kwargs)
|
|
|
|
class FunctionWrapper(_FunctionWrapperBase):
|
|
|
|
__bound_function_wrapper__ = BoundFunctionWrapper
|
|
|
|
def __init__(self, wrapped, wrapper, enabled=None):
|
|
# What it is we are wrapping here could be anything. We need to
|
|
# try and detect specific cases though. In particular, we need
|
|
# to detect when we are given something that is a method of a
|
|
# class. Further, we need to know when it is likely an instance
|
|
# method, as opposed to a class or static method. This can
|
|
# become problematic though as there isn't strictly a fool proof
|
|
# method of knowing.
|
|
#
|
|
# The situations we could encounter when wrapping a method are:
|
|
#
|
|
# 1. The wrapper is being applied as part of a decorator which
|
|
# is a part of the class definition. In this case what we are
|
|
# given is the raw unbound function, classmethod or staticmethod
|
|
# wrapper objects.
|
|
#
|
|
# The problem here is that we will not know we are being applied
|
|
# in the context of the class being set up. This becomes
|
|
# important later for the case of an instance method, because in
|
|
# that case we just see it as a raw function and can't
|
|
# distinguish it from wrapping a normal function outside of
|
|
# a class context.
|
|
#
|
|
# 2. The wrapper is being applied when performing monkey
|
|
# patching of the class type afterwards and the method to be
|
|
# wrapped was retrieved direct from the __dict__ of the class
|
|
# type. This is effectively the same as (1) above.
|
|
#
|
|
# 3. The wrapper is being applied when performing monkey
|
|
# patching of the class type afterwards and the method to be
|
|
# wrapped was retrieved from the class type. In this case
|
|
# binding will have been performed where the instance against
|
|
# which the method is bound will be None at that point.
|
|
#
|
|
# This case is a problem because we can no longer tell if the
|
|
# method was a static method, plus if using Python3, we cannot
|
|
# tell if it was an instance method as the concept of an
|
|
# unnbound method no longer exists.
|
|
#
|
|
# 4. The wrapper is being applied when performing monkey
|
|
# patching of an instance of a class. In this case binding will
|
|
# have been perfomed where the instance was not None.
|
|
#
|
|
# This case is a problem because we can no longer tell if the
|
|
# method was a static method.
|
|
#
|
|
# Overall, 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.
|
|
#
|
|
# As to not being able to identify static methods properly, we
|
|
# just hope that that isn't something people are going to want
|
|
# to wrap, or if they do suggest they do it the correct way by
|
|
# ensuring that it is decorated in the class definition itself,
|
|
# or patch it in the __dict__ of the class type.
|
|
#
|
|
# So to get the best outcome we can, whenever we aren't sure what
|
|
# it is, we label it as a 'function'. If it was already bound and
|
|
# that is rebound later, we assume that it will be an instance
|
|
# method and try an cope with the possibility that the 'self'
|
|
# argument it being passed as an explicit argument and shuffle
|
|
# the arguments around to extract 'self' for use as the instance.
|
|
|
|
if isinstance(wrapped, classmethod):
|
|
binding = 'classmethod'
|
|
|
|
elif isinstance(wrapped, staticmethod):
|
|
binding = 'staticmethod'
|
|
|
|
elif hasattr(wrapped, '__self__'):
|
|
if inspect.isclass(wrapped.__self__):
|
|
binding = 'classmethod'
|
|
else:
|
|
binding = 'function'
|
|
|
|
else:
|
|
binding = 'function'
|
|
|
|
super(FunctionWrapper, self).__init__(wrapped, None, wrapper,
|
|
enabled, binding)
|
|
|
|
try:
|
|
if not os.environ.get('WRAPT_DISABLE_EXTENSIONS'):
|
|
from ._wrappers import (ObjectProxy, CallableObjectProxy,
|
|
FunctionWrapper, BoundFunctionWrapper, _FunctionWrapperBase)
|
|
except ImportError:
|
|
pass
|
|
|
|
# Helper functions for applying wrappers to existing functions.
|
|
|
|
def resolve_path(module, name):
|
|
if isinstance(module, string_types):
|
|
__import__(module)
|
|
module = sys.modules[module]
|
|
|
|
parent = module
|
|
|
|
path = name.split('.')
|
|
attribute = path[0]
|
|
|
|
original = getattr(parent, attribute)
|
|
for attribute in path[1:]:
|
|
parent = original
|
|
|
|
# We can't just always use getattr() because in doing
|
|
# that on a class it will cause binding to occur which
|
|
# will complicate things later and cause some things not
|
|
# to work. For the case of a class we therefore access
|
|
# the __dict__ directly. To cope though with the wrong
|
|
# class being given to us, or a method being moved into
|
|
# a base class, we need to walk the class hierarchy to
|
|
# work out exactly which __dict__ the method was defined
|
|
# in, as accessing it from __dict__ will fail if it was
|
|
# not actually on the class given. Fallback to using
|
|
# getattr() if we can't find it. If it truly doesn't
|
|
# exist, then that will fail.
|
|
|
|
if inspect.isclass(original):
|
|
for cls in inspect.getmro(original):
|
|
if attribute in vars(cls):
|
|
original = vars(cls)[attribute]
|
|
break
|
|
else:
|
|
original = getattr(original, attribute)
|
|
|
|
else:
|
|
original = getattr(original, attribute)
|
|
|
|
return (parent, attribute, original)
|
|
|
|
def apply_patch(parent, attribute, replacement):
|
|
setattr(parent, attribute, replacement)
|
|
|
|
def wrap_object(module, name, factory, args=(), kwargs={}):
|
|
(parent, attribute, original) = resolve_path(module, name)
|
|
wrapper = factory(original, *args, **kwargs)
|
|
apply_patch(parent, attribute, wrapper)
|
|
return wrapper
|
|
|
|
# Function for applying a proxy object to an attribute of a class
|
|
# instance. The wrapper works by defining an attribute of the same name
|
|
# on the class which is a descriptor and which intercepts access to the
|
|
# instance attribute. Note that this cannot be used on attributes which
|
|
# are themselves defined by a property object.
|
|
|
|
class AttributeWrapper(object):
|
|
|
|
def __init__(self, attribute, factory, args, kwargs):
|
|
self.attribute = attribute
|
|
self.factory = factory
|
|
self.args = args
|
|
self.kwargs = kwargs
|
|
|
|
def __get__(self, instance, owner):
|
|
value = instance.__dict__[self.attribute]
|
|
return self.factory(value, *self.args, **self.kwargs)
|
|
|
|
def __set__(self, instance, value):
|
|
instance.__dict__[self.attribute] = value
|
|
|
|
def __delete__(self, instance):
|
|
del instance.__dict__[self.attribute]
|
|
|
|
def wrap_object_attribute(module, name, factory, args=(), kwargs={}):
|
|
path, attribute = name.rsplit('.', 1)
|
|
parent = resolve_path(module, path)[2]
|
|
wrapper = AttributeWrapper(attribute, factory, args, kwargs)
|
|
apply_patch(parent, attribute, wrapper)
|
|
return wrapper
|
|
|
|
# Functions for creating a simple decorator using a FunctionWrapper,
|
|
# plus short cut functions for applying wrappers to functions. These are
|
|
# for use when doing monkey patching. For a more featured way of
|
|
# creating decorators see the decorator decorator instead.
|
|
|
|
def function_wrapper(wrapper):
|
|
def _wrapper(wrapped, instance, args, kwargs):
|
|
target_wrapped = args[0]
|
|
if instance is None:
|
|
target_wrapper = wrapper
|
|
elif inspect.isclass(instance):
|
|
target_wrapper = wrapper.__get__(None, instance)
|
|
else:
|
|
target_wrapper = wrapper.__get__(instance, type(instance))
|
|
return FunctionWrapper(target_wrapped, target_wrapper)
|
|
return FunctionWrapper(wrapper, _wrapper)
|
|
|
|
def wrap_function_wrapper(module, name, wrapper):
|
|
return wrap_object(module, name, FunctionWrapper, (wrapper,))
|
|
|
|
def patch_function_wrapper(module, name):
|
|
def _wrapper(wrapper):
|
|
return wrap_object(module, name, FunctionWrapper, (wrapper,))
|
|
return _wrapper
|
|
|
|
def transient_function_wrapper(module, name):
|
|
def _decorator(wrapper):
|
|
def _wrapper(wrapped, instance, args, kwargs):
|
|
target_wrapped = args[0]
|
|
if instance is None:
|
|
target_wrapper = wrapper
|
|
elif inspect.isclass(instance):
|
|
target_wrapper = wrapper.__get__(None, instance)
|
|
else:
|
|
target_wrapper = wrapper.__get__(instance, type(instance))
|
|
def _execute(wrapped, instance, args, kwargs):
|
|
(parent, attribute, original) = resolve_path(module, name)
|
|
replacement = FunctionWrapper(original, target_wrapper)
|
|
setattr(parent, attribute, replacement)
|
|
try:
|
|
return wrapped(*args, **kwargs)
|
|
finally:
|
|
setattr(parent, attribute, original)
|
|
return FunctionWrapper(target_wrapped, _execute)
|
|
return FunctionWrapper(wrapper, _wrapper)
|
|
return _decorator
|
|
|
|
# A weak function proxy. This will work on instance methods, class
|
|
# methods, static methods and regular functions. Special treatment is
|
|
# needed for the method types because the bound method is effectively a
|
|
# transient object and applying a weak reference to one will immediately
|
|
# result in it being destroyed and the weakref callback called. The weak
|
|
# reference is therefore applied to the instance the method is bound to
|
|
# and the original function. The function is then rebound at the point
|
|
# of a call via the weak function proxy.
|
|
|
|
def _weak_function_proxy_callback(ref, proxy, callback):
|
|
if proxy._self_expired:
|
|
return
|
|
|
|
proxy._self_expired = True
|
|
|
|
# This could raise an exception. We let it propagate back and let
|
|
# the weakref.proxy() deal with it, at which point it generally
|
|
# prints out a short error message direct to stderr and keeps going.
|
|
|
|
if callback is not None:
|
|
callback(proxy)
|
|
|
|
class WeakFunctionProxy(ObjectProxy):
|
|
|
|
__slots__ = ('_self_expired', '_self_instance')
|
|
|
|
def __init__(self, wrapped, callback=None):
|
|
# We need to determine if the wrapped function is actually a
|
|
# bound method. In the case of a bound method, we need to keep a
|
|
# reference to the original unbound function and the instance.
|
|
# This is necessary because if we hold a reference to the bound
|
|
# function, it will be the only reference and given it is a
|
|
# temporary object, it will almost immediately expire and
|
|
# the weakref callback triggered. So what is done is that we
|
|
# hold a reference to the instance and unbound function and
|
|
# when called bind the function to the instance once again and
|
|
# then call it. Note that we avoid using a nested function for
|
|
# the callback here so as not to cause any odd reference cycles.
|
|
|
|
_callback = callback and functools.partial(
|
|
_weak_function_proxy_callback, proxy=self,
|
|
callback=callback)
|
|
|
|
self._self_expired = False
|
|
|
|
if isinstance(wrapped, _FunctionWrapperBase):
|
|
self._self_instance = weakref.ref(wrapped._self_instance,
|
|
_callback)
|
|
|
|
if wrapped._self_parent is not None:
|
|
super(WeakFunctionProxy, self).__init__(
|
|
weakref.proxy(wrapped._self_parent, _callback))
|
|
|
|
else:
|
|
super(WeakFunctionProxy, self).__init__(
|
|
weakref.proxy(wrapped, _callback))
|
|
|
|
return
|
|
|
|
try:
|
|
self._self_instance = weakref.ref(wrapped.__self__, _callback)
|
|
|
|
super(WeakFunctionProxy, self).__init__(
|
|
weakref.proxy(wrapped.__func__, _callback))
|
|
|
|
except AttributeError:
|
|
self._self_instance = None
|
|
|
|
super(WeakFunctionProxy, self).__init__(
|
|
weakref.proxy(wrapped, _callback))
|
|
|
|
def __call__(self, *args, **kwargs):
|
|
# We perform a boolean check here on the instance and wrapped
|
|
# function as that will trigger the reference error prior to
|
|
# calling if the reference had expired.
|
|
|
|
instance = self._self_instance and self._self_instance()
|
|
function = self.__wrapped__ and self.__wrapped__
|
|
|
|
# If the wrapped function was originally a bound function, for
|
|
# which we retained a reference to the instance and the unbound
|
|
# function we need to rebind the function and then call it. If
|
|
# not just called the wrapped function.
|
|
|
|
if instance is None:
|
|
return self.__wrapped__(*args, **kwargs)
|
|
|
|
return function.__get__(instance, type(instance))(*args, **kwargs)
|