/usr/lib/python2.7/dist-packages/framework/patterns/decorator.py is in fso-frameworkd 0.10.1-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 | """
Decorator module, see
http://www.phyast.pitt.edu/~micheles/python/documentation.html
for the documentation and below for the licence.
"""
## The basic trick is to generate the source code for the decorated function
## with the right signature and to evaluate it.
## Uncomment the statement 'print >> sys.stderr, func_src' in _decorator
## to understand what is going on.
__all__ = ["decorator", "new_wrapper", "getinfo"]
import inspect, sys
try:
set
except NameError:
from sets import Set as set
def getinfo(func):
"""
Returns an info dictionary containing:
- name (the name of the function : str)
- argnames (the names of the arguments : list)
- defaults (the values of the default arguments : tuple)
- signature (the signature : str)
- doc (the docstring : str)
- module (the module name : str)
- dict (the function __dict__ : str)
>>> def f(self, x=1, y=2, *args, **kw): pass
>>> info = getinfo(f)
>>> info["name"]
'f'
>>> info["argnames"]
['self', 'x', 'y', 'args', 'kw']
>>> info["defaults"]
(1, 2)
>>> info["signature"]
'self, x, y, *args, **kw'
"""
assert inspect.ismethod(func) or inspect.isfunction(func)
regargs, varargs, varkwargs, defaults = inspect.getargspec(func)
argnames = list(regargs)
if varargs:
argnames.append(varargs)
if varkwargs:
argnames.append(varkwargs)
signature = inspect.formatargspec(regargs, varargs, varkwargs, defaults,
formatvalue=lambda value: "")[1:-1]
return dict(name=func.__name__, argnames=argnames, signature=signature,
defaults = func.func_defaults, doc=func.__doc__,
module=func.__module__, dict=func.__dict__,
globals=func.func_globals, closure=func.func_closure)
# akin to functools.update_wrapper
def update_wrapper(wrapper, model, infodict=None):
infodict = infodict or getinfo(model)
try:
wrapper.__name__ = infodict['name']
except: # Python version < 2.4
pass
wrapper.__doc__ = infodict['doc']
wrapper.__module__ = infodict['module']
wrapper.__dict__.update(infodict['dict'])
wrapper.func_defaults = infodict['defaults']
wrapper.undecorated = model
return wrapper
def new_wrapper(wrapper, model):
"""
An improvement over functools.update_wrapper. The wrapper is a generic
callable object. It works by generating a copy of the wrapper with the
right signature and by updating the copy, not the original.
Moreovoer, 'model' can be a dictionary with keys 'name', 'doc', 'module',
'dict', 'defaults'.
"""
if isinstance(model, dict):
infodict = model
else: # assume model is a function
infodict = getinfo(model)
assert not '_wrapper_' in infodict["argnames"], (
'"_wrapper_" is a reserved argument name!')
src = "lambda %(signature)s: _wrapper_(%(signature)s)" % infodict
funcopy = eval(src, dict(_wrapper_=wrapper))
return update_wrapper(funcopy, model, infodict)
# helper used in decorator_factory
def __call__(self, func):
return new_wrapper(lambda *a, **k : self.call(func, *a, **k), func)
def decorator_factory(cls):
"""
Take a class with a ``.caller`` method and return a callable decorator
object. It works by adding a suitable __call__ method to the class;
it raises a TypeError if the class already has a nontrivial __call__
method.
"""
attrs = set(dir(cls))
if '__call__' in attrs:
raise TypeError('You cannot decorate a class with a nontrivial '
'__call__ method')
if 'call' not in attrs:
raise TypeError('You cannot decorate a class without a '
'.call method')
cls.__call__ = __call__
return cls
def decorator(caller):
"""
General purpose decorator factory: takes a caller function as
input and returns a decorator with the same attributes.
A caller function is any function like this::
def caller(func, *args, **kw):
# do something
return func(*args, **kw)
Here is an example of usage:
>>> @decorator
... def chatty(f, *args, **kw):
... print "Calling %r" % f.__name__
... return f(*args, **kw)
>>> chatty.__name__
'chatty'
>>> @chatty
... def f(): pass
...
>>> f()
Calling 'f'
decorator can also take in input a class with a .caller method; in this
case it converts the class into a factory of callable decorator objects.
See the documentation for an example.
"""
if inspect.isclass(caller):
return decorator_factory(caller)
def _decorator(func): # the real meat is here
infodict = getinfo(func)
argnames = infodict['argnames']
assert not ('_call_' in argnames or '_func_' in argnames), (
'You cannot use _call_ or _func_ as argument names!')
src = "lambda %(signature)s: _call_(_func_, %(signature)s)" % infodict
# import sys; print >> sys.stderr, src # for debugging purposes
dec_func = eval(src, dict(_func_=func, _call_=caller))
return update_wrapper(dec_func, func, infodict)
return update_wrapper(_decorator, caller)
if __name__ == "__main__":
import doctest; doctest.testmod()
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