cafe-grader-web

Location: cafe-grader-web/lib/assets/Lib/copyreg.py - annotation

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Commit Description:
Merge pull request #17 from nattee/master...
Commit Description:
Merge pull request #17 from nattee/master upgrade to current working snapshot
References:
r715:88baf2c40c51 merge default
File last commit:
r584:056392c00e67 merge java
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lib/assets/Lib/copyreg.py | 196 lines | 6.6 KiB | text/x-python | PythonLexer |
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merge with algo and add brython files that were missing
 r584 """Helper to provide extensibility for pickle.
This is only useful to add pickle support for extension types defined in
C, not for instances of user-defined classes.
"""
__all__ = ["pickle", "constructor",
"add_extension", "remove_extension", "clear_extension_cache"]
dispatch_table = {}
def pickle(ob_type, pickle_function, constructor_ob=None):
if not callable(pickle_function):
raise TypeError("reduction functions must be callable")
dispatch_table[ob_type] = pickle_function
# The constructor_ob function is a vestige of safe for unpickling.
# There is no reason for the caller to pass it anymore.
if constructor_ob is not None:
constructor(constructor_ob)
def constructor(object):
if not callable(object):
raise TypeError("constructors must be callable")
# Example: provide pickling support for complex numbers.
try:
complex
except NameError:
pass
else:
def pickle_complex(c):
return complex, (c.real, c.imag)
pickle(complex, pickle_complex, complex)
# Support for pickling new-style objects
def _reconstructor(cls, base, state):
if base is object:
obj = object.__new__(cls)
else:
obj = base.__new__(cls, state)
if base.__init__ != object.__init__:
base.__init__(obj, state)
return obj
_HEAPTYPE = 1<<9
# Python code for object.__reduce_ex__ for protocols 0 and 1
def _reduce_ex(self, proto):
assert proto < 2
for base in self.__class__.__mro__:
if hasattr(base, '__flags__') and not base.__flags__ & _HEAPTYPE:
break
else:
base = object # not really reachable
if base is object:
state = None
else:
if base is self.__class__:
raise TypeError("can't pickle %s objects" % base.__name__)
state = base(self)
args = (self.__class__, base, state)
try:
getstate = self.__getstate__
except AttributeError:
if getattr(self, "__slots__", None):
raise TypeError("a class that defines __slots__ without "
"defining __getstate__ cannot be pickled")
try:
dict = self.__dict__
except AttributeError:
dict = None
else:
dict = getstate()
if dict:
return _reconstructor, args, dict
else:
return _reconstructor, args
# Helper for __reduce_ex__ protocol 2
def __newobj__(cls, *args):
return cls.__new__(cls, *args)
def _slotnames(cls):
"""Return a list of slot names for a given class.
This needs to find slots defined by the class and its bases, so we
can't simply return the __slots__ attribute. We must walk down
the Method Resolution Order and concatenate the __slots__ of each
class found there. (This assumes classes don't modify their
__slots__ attribute to misrepresent their slots after the class is
defined.)
"""
# Get the value from a cache in the class if possible
names = cls.__dict__.get("__slotnames__")
if names is not None:
return names
# Not cached -- calculate the value
names = []
if not hasattr(cls, "__slots__"):
# This class has no slots
pass
else:
# Slots found -- gather slot names from all base classes
for c in cls.__mro__:
if "__slots__" in c.__dict__:
slots = c.__dict__['__slots__']
# if class has a single slot, it can be given as a string
if isinstance(slots, str):
slots = (slots,)
for name in slots:
# special descriptors
if name in ("__dict__", "__weakref__"):
continue
# mangled names
elif name.startswith('__') and not name.endswith('__'):
names.append('_%s%s' % (c.__name__, name))
else:
names.append(name)
# Cache the outcome in the class if at all possible
try:
cls.__slotnames__ = names
except:
pass # But don't die if we can't
return names
# A registry of extension codes. This is an ad-hoc compression
# mechanism. Whenever a global reference to <module>, <name> is about
# to be pickled, the (<module>, <name>) tuple is looked up here to see
# if it is a registered extension code for it. Extension codes are
# universal, so that the meaning of a pickle does not depend on
# context. (There are also some codes reserved for local use that
# don't have this restriction.) Codes are positive ints; 0 is
# reserved.
_extension_registry = {} # key -> code
_inverted_registry = {} # code -> key
_extension_cache = {} # code -> object
# Don't ever rebind those names: pickling grabs a reference to them when
# it's initialized, and won't see a rebinding.
def add_extension(module, name, code):
"""Register an extension code."""
code = int(code)
if not 1 <= code <= 0x7fffffff:
raise ValueError("code out of range")
key = (module, name)
if (_extension_registry.get(key) == code and
_inverted_registry.get(code) == key):
return # Redundant registrations are benign
if key in _extension_registry:
raise ValueError("key %s is already registered with code %s" %
(key, _extension_registry[key]))
if code in _inverted_registry:
raise ValueError("code %s is already in use for key %s" %
(code, _inverted_registry[code]))
_extension_registry[key] = code
_inverted_registry[code] = key
def remove_extension(module, name, code):
"""Unregister an extension code. For testing only."""
key = (module, name)
if (_extension_registry.get(key) != code or
_inverted_registry.get(code) != key):
raise ValueError("key %s is not registered with code %s" %
(key, code))
del _extension_registry[key]
del _inverted_registry[code]
if code in _extension_cache:
del _extension_cache[code]
def clear_extension_cache():
_extension_cache.clear()
# Standard extension code assignments
# Reserved ranges
# First Last Count Purpose
# 1 127 127 Reserved for Python standard library
# 128 191 64 Reserved for Zope
# 192 239 48 Reserved for 3rd parties
# 240 255 16 Reserved for private use (will never be assigned)
# 256 Inf Inf Reserved for future assignment
# Extension codes are assigned by the Python Software Foundation.