[Python-checkins] CVS: python/dist/src/Lib copy_reg.py,1.5,1.6
Guido van Rossum
gvanrossum@users.sourceforge.net
Tue, 25 Sep 2001 09:26:00 -0700
Update of /cvsroot/python/python/dist/src/Lib
In directory usw-pr-cvs1:/tmp/cvs-serv12467/Lib
Modified Files:
copy_reg.py
Log Message:
- Provisional support for pickling new-style objects. (*)
- Made cls.__module__ writable.
- Ensure that obj.__dict__ is returned as {}, not None, even upon first
reference; it simply springs into life when you ask for it.
(*) The pickling support is provisional for the following reasons:
- It doesn't support classes with __slots__.
- It relies on additional support in copy_reg.py: the C method
__reduce__, defined in the object class, really calls calling
copy_reg._reduce(obj). Eventually the Python code in copy_reg.py
needs to be migrated to C, but I'd like to experiment with the
Python implementation first. The _reduce() code also relies on an
additional helper function, _reconstructor(), defined in
copy_reg.py; this should also be reimplemented in C.
Index: copy_reg.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/copy_reg.py,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -d -r1.5 -r1.6
*** copy_reg.py 2001/01/20 19:54:20 1.5
--- copy_reg.py 2001/09/25 16:25:58 1.6
***************
*** 34,35 ****
--- 34,64 ----
pickle(type(1j), pickle_complex, complex)
+
+ # Support for picking new-style objects
+
+ _dummy_classes = {}
+
+ def _reconstructor(cls, base, state):
+ dummy = _dummy_classes.get(base)
+ if dummy is None:
+ class dummy(base): pass
+ _dummy_classes[base] = dummy
+ obj = dummy(state)
+ obj._foo = 1; del obj._foo # hack to create __dict__
+ obj.__class__ = cls
+ return obj
+ _reconstructor.__safe_for_unpickling__ = 1
+
+ _HEAPTYPE = 1<<9
+
+ def _reduce(self):
+ for base in self.__class__.__mro__:
+ if not base.__flags__ & _HEAPTYPE:
+ break
+ else:
+ base = object # not really reachable
+ if base is object:
+ state = None
+ else:
+ state = base(self)
+ return _reconstructor, (self.__class__, base, state), self.__dict__