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72 lines
1.9 KiB
72 lines
1.9 KiB
"""Helper to provide extensibility for pickle/cPickle. |
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This is only useful to add pickle support for extension types defined in |
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C, not for instances of user-defined classes. |
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""" |
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from types import ClassType as _ClassType |
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__all__ = ["pickle","constructor"] |
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dispatch_table = {} |
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safe_constructors = {} |
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def pickle(ob_type, pickle_function, constructor_ob=None): |
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if type(ob_type) is _ClassType: |
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raise TypeError("copy_reg is not intended for use with classes") |
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if not callable(pickle_function): |
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raise TypeError("reduction functions must be callable") |
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dispatch_table[ob_type] = pickle_function |
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if constructor_ob is not None: |
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constructor(constructor_ob) |
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def constructor(object): |
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if not callable(object): |
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raise TypeError("constructors must be callable") |
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safe_constructors[object] = 1 |
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# Example: provide pickling support for complex numbers. |
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def pickle_complex(c): |
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return complex, (c.real, c.imag) |
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pickle(type(1j), pickle_complex, complex) |
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# Support for picking new-style objects |
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def _reconstructor(cls, base, state): |
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obj = base.__new__(cls, state) |
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base.__init__(obj, state) |
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return obj |
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_reconstructor.__safe_for_unpickling__ = 1 |
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_HEAPTYPE = 1<<9 |
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def _reduce(self): |
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for base in self.__class__.__mro__: |
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if hasattr(base, '__flags__') and not base.__flags__ & _HEAPTYPE: |
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break |
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else: |
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base = object # not really reachable |
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if base is object: |
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state = None |
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else: |
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if base is self.__class__: |
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raise TypeError, "can't pickle %s objects" % base.__name__ |
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state = base(self) |
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args = (self.__class__, base, state) |
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try: |
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getstate = self.__getstate__ |
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except AttributeError: |
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try: |
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dict = self.__dict__ |
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except AttributeError: |
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dict = None |
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else: |
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dict = getstate() |
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if dict: |
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return _reconstructor, args, dict |
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else: |
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return _reconstructor, args
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