[Python-checkins] python/dist/src/Lib pickle.py,1.109,1.110

2003年1月28日 08:34:25 -0800

Update of /cvsroot/python/python/dist/src/Lib
In directory sc8-pr-cvs1:/tmp/cvs-serv24598
Modified Files:
	pickle.py 
Log Message:
Made save() fit on a page, while adding comments. (I moved some type
checks to save_reduce(), which can also be called from a subclass.)
Also tweaked some more comments.
Index: pickle.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/pickle.py,v
retrieving revision 1.109
retrieving revision 1.110
diff -C2 -d -r1.109 -r1.110
*** pickle.py	28 Jan 2003 16:23:33 -0000	1.109
--- pickle.py	28 Jan 2003 16:34:19 -0000	1.110
***************
*** 33,36 ****
--- 33,37 ----
 import struct
 import re
+ import warnings

 __all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler",
***************
*** 40,44 ****
 format_version = "2.0" # File format version we write
 compatible_formats = ["1.0", # Original protocol 0
! "1.1", # Protocol 0 with class supprt added
 "1.2", # Original protocol 1
 "1.3", # Protocol 1 with BINFLOAT added
--- 41,45 ----
 format_version = "2.0" # File format version we write
 compatible_formats = ["1.0", # Original protocol 0
! "1.1", # Protocol 0 with INST added
 "1.2", # Original protocol 1
 "1.3", # Protocol 1 with BINFLOAT added
***************
*** 250,277 ****

 def save(self, obj):
 pid = self.persistent_id(obj)
! if pid is not None:
 self.save_pers(pid)
 return

! memo = self.memo
! d = id(obj)
! if d in memo:
! self.write(self.get(memo[d][0]))
 return

 t = type(obj)
! try:
! f = self.dispatch[t]
! except KeyError:
! pass
! else:
! f(self, obj)
 return

! # The dispatch table doesn't know about type t.
 try:
 issc = issubclass(t, TypeType)
! except TypeError: # t is not a class
 issc = 0
 if issc:
--- 251,277 ----

 def save(self, obj):
+ # Check for persistent id (defined by a subclass)
 pid = self.persistent_id(obj)
! if pid:
 self.save_pers(pid)
 return

! # Check the memo
! x = self.memo.get(id(obj))
! if x:
! self.write(self.get(x[0]))
 return

+ # Check the type dispatch table
 t = type(obj)
! f = self.dispatch.get(t)
! if f:
! f(self, obj) # Call unbound method with explicit self
 return

! # Check for a class with a custom metaclass; treat as regular class
 try:
 issc = issubclass(t, TypeType)
! except TypeError: # t is not a class (old Boost; see SF #502085)
 issc = 0
 if issc:
***************
*** 279,329 ****
 return

! try:
! reduce = dispatch_table[t]
! except KeyError:
! try:
! reduce = obj.__reduce__
! except AttributeError:
! raise PicklingError, \
! "can't pickle %s object: %s" % (`t.__name__`,
! `obj`)
! else:
! tup = reduce()
 else:
! tup = reduce(obj)

! if type(tup) is StringType:
! self.save_global(obj, tup)
 return

! if type(tup) is not TupleType:
! raise PicklingError, "Value returned by %s must be a " \
! "tuple" % reduce
! 
! l = len(tup)
! 
! if (l != 2) and (l != 3):
! raise PicklingError, "tuple returned by %s must contain " \
! "only two or three elements" % reduce
! 
! callable = tup[0]
! arg_tup = tup[1]

! if l > 2:
! state = tup[2]
! else:
 state = None

! if type(arg_tup) is not TupleType and arg_tup is not None:
! raise PicklingError, "Second element of tuple returned " \
! "by %s must be a tuple" % reduce
! 
! self.save_reduce(callable, arg_tup, state)
 self.memoize(obj)

 def persistent_id(self, obj):
 return None

 def save_pers(self, pid):
 if self.bin:
 self.save(pid)
--- 279,324 ----
 return

! # Check copy_reg.dispatch_table
! reduce = dispatch_table.get(t)
! if reduce:
! rv = reduce(obj)
 else:
! # Check for __reduce__ method
! reduce = getattr(obj, "__reduce__", None)
! if not reduce:
! raise PicklingError("Can't pickle %r object: %r" %
! (t.__name__, obj))
! rv = reduce()

! # Check for string returned by reduce(), meaning "save as global"
! if type(rv) is StringType:
! self.save_global(obj, rv)
 return

! # Assert that reduce() returned a tuple
! if type(rv) is not TupleType:
! raise PicklingError("%s must return string or tuple" % reduce)

! # Assert that it returned a 2-tuple or 3-tuple, and unpack it
! l = len(rv)
! if l == 2:
! func, args = rv
 state = None
+ elif l == 3:
+ func, args, state = rv
+ else:
+ raise PicklingError("Tuple returned by %s must have "
+ "exactly two or three elements" % reduce)

! # Save the reduce() output and finally memoize the object
! self.save_reduce(func, args, state)
 self.memoize(obj)

 def persistent_id(self, obj):
+ # This exists so a subclass can override it
 return None

 def save_pers(self, pid):
+ # Save a persistent id reference
 if self.bin:
 self.save(pid)
***************
*** 332,345 ****
 self.write(PERSID + str(pid) + '\n')

! def save_reduce(self, acallable, arg_tup, state = None):
! write = self.write
! save = self.save

! if not callable(acallable):
! raise PicklingError("__reduce__() must return callable as "
! "first argument, not %s" % `acallable`)

! save(acallable)
! save(arg_tup)
 write(REDUCE)

--- 327,353 ----
 self.write(PERSID + str(pid) + '\n')

! def save_reduce(self, func, args, state=None):
! # This API is be called by some subclasses

! # Assert that args is a tuple or None
! if not isinstance(args, TupleType):
! if args is None:
! # A hack for Jim Fulton's ExtensionClass, now deprecated.
! # See load_reduce()
! warnings.warn("__basicnew__ special case is deprecated",
! DeprecationWarning)
! else:
! raise PicklingError(
! "args from reduce() should be a tuple")

! # Assert that func is callable
! if not callable(func):
! raise PicklingError("func from reduce should be callable")
! 
! save = self.save
! write = self.write
! 
! save(func)
! save(args)
 write(REDUCE)

***************
*** 348,351 ****
--- 356,361 ----
 write(BUILD)

+ # Methods below this point are dispatched through the dispatch table
+ 
 dispatch = {}

***************
*** 1029,1035 ****

 if arg_tup is None:
! import warnings
! warnings.warn("The None return argument form of __reduce__ is "
! "deprecated. Return a tuple of arguments instead.",
 DeprecationWarning)
 value = callable.__basicnew__()
--- 1039,1044 ----

 if arg_tup is None:
! # A hack for Jim Fulton's ExtensionClass, now deprecated
! warnings.warn("__basicnew__ special case is deprecated",
 DeprecationWarning)
 value = callable.__basicnew__()