"""Create portable serialized representations of Python objects. See module cPickle for a (much) faster implementation.See module copy_reg for a mechanism for registering custom picklers.See module pickletools source for extensive comments. Classes: Pickler Unpickler Functions: dump(object, file) dumps(object) -> string load(file) -> object loads(string) -> object Misc variables: __version__ format_version compatible_formats """ __version__ = "$Revision: 38432 $" # Code version from types import *from copy_reg import dispatch_tablefrom copy_reg import _extension_registry, _inverted_registry, _extension_cacheimport marshalimport sysimport structimport re __all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler", "Unpickler", "dump", "dumps", "load", "loads"] # These are purely informational; no code uses these.format_version = "2.0" # File format version we writecompatible_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 "2.0", # Protocol 2 ] # Old format versions we can read # Keep in synch with cPickle. This is the highest protocol number we# know how to read.HIGHEST_PROTOCOL = 2 # Why use struct.pack() for pickling but marshal.loads() for# unpickling? struct.pack() is 40% faster than marshal.dumps(), but# marshal.loads() is twice as fast as struct.unpack()!mloads = marshal.loads class PickleError(Exception): """A common base class for the other pickling exceptions.""" pass class PicklingError(PickleError): """This exception is raised when an unpicklable object is passed to the dump() method. """ pass class UnpicklingError(PickleError): """This exception is raised when there is a problem unpickling an object, such as a security violation. Note that other exceptions may also be raised during unpickling, including (but not necessarily limited to) AttributeError, EOFError, ImportError, and IndexError. """ pass # An instance of _Stop is raised by Unpickler.load_stop() in response to# the STOP opcode, passing the object that is the result of unpickling.class _Stop(Exception): def __init__(self, value): self.value = value # Jython has PyStringMap; it's a dict subclass with string keystry: from org.python.core import PyStringMapexcept ImportError: PyStringMap = None # UnicodeType may or may not be exported (normally imported from types)try: UnicodeTypeexcept NameError: UnicodeType = None # Pickle opcodes. See pickletools.py for extensive docs. The listing# here is in kind-of alphabetical order of 1-character pickle code.# pickletools groups them by purpose. MARK = '(' # push special markobject on stackSTOP = '.' # every pickle ends with STOPPOP = '0' # discard topmost stack itemPOP_MARK = '1' # discard stack top through topmost markobjectDUP = '2' # duplicate top stack itemFLOAT = 'F' # push float object; decimal string argumentINT = 'I' # push integer or bool; decimal string argumentBININT = 'J' # push four-byte signed intBININT1 = 'K' # push 1-byte unsigned intLONG = 'L' # push long; decimal string argumentBININT2 = 'M' # push 2-byte unsigned intNONE = 'N' # push NonePERSID = 'P' # push persistent object; id is taken from string argBINPERSID = 'Q' # " " " ; " " " " stackREDUCE = 'R' # apply callable to argtuple, both on stackSTRING = 'S' # push string; NL-terminated string argumentBINSTRING = 'T' # push string; counted binary string argumentSHORT_BINSTRING = 'U' # " " ; " " " " < 256 bytesUNICODE = 'V' # push Unicode string; raw-unicode-escaped'd argumentBINUNICODE = 'X' # " " " ; counted UTF-8 string argumentAPPEND = 'a' # append stack top to list below itBUILD = 'b' # call __setstate__ or __dict__.update()GLOBAL = 'c' # push self.find_class(modname, name); 2 string argsDICT = 'd' # build a dict from stack itemsEMPTY_DICT = '}' # push empty dictAPPENDS = 'e' # extend list on stack by topmost stack sliceGET = 'g' # push item from memo on stack; index is string argBINGET = 'h' # " " " " " " ; " " 1-byte argINST = 'i' # build & push class instanceLONG_BINGET = 'j' # push item from memo on stack; index is 4-byte argLIST = 'l' # build list from topmost stack itemsEMPTY_LIST = ']' # push empty listOBJ = 'o' # build & push class instancePUT = 'p' # store stack top in memo; index is string argBINPUT = 'q' # " " " " " ; " " 1-byte argLONG_BINPUT = 'r' # " " " " " ; " " 4-byte argSETITEM = 's' # add key+value pair to dictTUPLE = 't' # build tuple from topmost stack itemsEMPTY_TUPLE = ')' # push empty tupleSETITEMS = 'u' # modify dict by adding topmost key+value pairsBINFLOAT = 'G' # push float; arg is 8-byte float encoding TRUE = 'I01\n' # not an opcode; see INT docs in pickletools.pyFALSE = 'I00\n' # not an opcode; see INT docs in pickletools.py # Protocol 2 PROTO = '\x80' # identify pickle protocolNEWOBJ = '\x81' # build object by applying cls.__new__ to argtupleEXT1 = '\x82' # push object from extension registry; 1-byte indexEXT2 = '\x83' # ditto, but 2-byte indexEXT4 = '\x84' # ditto, but 4-byte indexTUPLE1 = '\x85' # build 1-tuple from stack topTUPLE2 = '\x86' # build 2-tuple from two topmost stack itemsTUPLE3 = '\x87' # build 3-tuple from three topmost stack itemsNEWTRUE = '\x88' # push TrueNEWFALSE = '\x89' # push FalseLONG1 = '\x8a' # push long from < 256 bytesLONG4 = '\x8b' # push really big long _tuplesize2code = [EMPTY_TUPLE, TUPLE1, TUPLE2, TUPLE3] __all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$",x)])del x # Pickling machinery class Pickler: def __init__(self, file, protocol=None): """This takes a file-like object for writing a pickle data stream. The optional protocol argument tells the pickler to use the given protocol; supported protocols are 0, 1, 2. The default protocol is 0, to be backwards compatible. (Protocol 0 is the only protocol that can be written to a file opened in text mode and read back successfully. When using a protocol higher than 0, make sure the file is opened in binary mode, both when pickling and unpickling.) Protocol 1 is more efficient than protocol 0; protocol 2 is more efficient than protocol 1. Specifying a negative protocol version selects the highest protocol version supported. The higher the protocol used, the more recent the version of Python needed to read the pickle produced. The file parameter must have a write() method that accepts a single string argument. It can thus be an open file object, a StringIO object, or any other custom object that meets this interface. """ if protocol is None: protocol = 0 if protocol < 0: protocol = HIGHEST_PROTOCOL elif not 0 <= protocol <= HIGHEST_PROTOCOL: raise ValueError("pickle protocol must be <= %d" % HIGHEST_PROTOCOL) self.write = file.write self.memo = {} self.proto = int(protocol) self.bin = protocol >= 1 self.fast = 0 def clear_memo(self): """Clears the pickler's "memo". The memo is the data structure that remembers which objects the pickler has already seen, so that shared or recursive objects are pickled by reference and not by value. This method is useful when re-using picklers. """ self.memo.clear() def dump(self, obj): """Write a pickled representation of obj to the open file.""" if self.proto >= 2: self.write(PROTO + chr(self.proto)) self.save(obj) self.write(STOP) def memoize(self, obj): """Store an object in the memo.""" # The Pickler memo is a dictionary mapping object ids to 2-tuples # that contain the Unpickler memo key and the object being memoized. # The memo key is written to the pickle and will become # the key in the Unpickler's memo. The object is stored in the # Pickler memo so that transient objects are kept alive during # pickling. # The use of the Unpickler memo length as the memo key is just a # convention. The only requirement is that the memo values be unique. # But there appears no advantage to any other scheme, and this # scheme allows the Unpickler memo to be implemented as a plain (but # growable) array, indexed by memo key. if self.fast: return assert id(obj) not in self.memo memo_len = len(self.memo) self.write(self.put(memo_len)) self.memo[id(obj)] = memo_len, obj # Return a PUT (BINPUT, LONG_BINPUT) opcode string, with argument i. def put(self, i, pack=struct.pack): if self.bin: if i < 256: return BINPUT + chr(i) else: return LONG_BINPUT + pack("<i", i) return PUT + repr(i) + '\n' # Return a GET (BINGET, LONG_BINGET) opcode string, with argument i. def get(self, i, pack=struct.pack): if self.bin: if i < 256: return BINGET + chr(i) else: return LONG_BINGET + pack("<i", i) return GET + repr(i) + '\n' 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: self.save_global(obj) return # Check copy_reg.dispatch_table reduce = dispatch_table.get(t) if reduce: rv = reduce(obj) else: # Check for a __reduce_ex__ method, fall back to __reduce__ reduce = getattr(obj, "__reduce_ex__", None) if reduce: rv = reduce(self.proto) else: reduce = getattr(obj, "__reduce__", None) if reduce: rv = reduce() else: raise PicklingError("Can't pickle %r object: %r" % (t.__name__, obj)) # 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 an appropriately sized tuple l = len(rv) if not (2 <= l <= 5): raise PicklingError("Tuple returned by %s must have " "two to five elements" % reduce) # Save the reduce() output and finally memoize the object self.save_reduce(obj=obj, *rv) 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) self.write(BINPERSID) else: self.write(PERSID + str(pid) + '\n') def save_reduce(self, func, args, state=None, listitems=None, dictitems=None, obj=None): # This API is called by some subclasses # Assert that args is a tuple or None if not isinstance(args, TupleType): 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 # Protocol 2 special case: if func's name is __newobj__, use NEWOBJ if self.proto >= 2 and getattr(func, "__name__", "") == "__newobj__": # A __reduce__ implementation can direct protocol 2 to # use the more efficient NEWOBJ opcode, while still # allowing protocol 0 and 1 to work normally. For this to # work, the function returned by __reduce__ should be # called __newobj__, and its first argument should be a # new-style class. The implementation for __newobj__ # should be as follows, although pickle has no way to # verify this: # # def __newobj__(cls, *args): # return cls.__new__(cls, *args) # # Protocols 0 and 1 will pickle a reference to __newobj__, # while protocol 2 (and above) will pickle a reference to # cls, the remaining args tuple, and the NEWOBJ code, # which calls cls.__new__(cls, *args) at unpickling time # (see load_newobj below). If __reduce__ returns a # three-tuple, the state from the third tuple item will be # pickled regardless of the protocol, calling __setstate__ # at unpickling time (see load_build below). # # Note that no standard __newobj__ implementation exists; # you have to provide your own. This is to enforce # compatibility with Python 2.2 (pickles written using # protocol 0 or 1 in Python 2.3 should be unpicklable by # Python 2.2). cls = args[0] if not hasattr(cls, "__new__"): raise PicklingError( "args[0] from __newobj__ args has no __new__") if obj is not None and cls is not obj.__class__: raise PicklingError( "args[0] from __newobj__ args has the wrong class") args = args[1:] save(cls) save(args) write(NEWOBJ) else: save(func) save(args) write(REDUCE) if obj is not None: self.memoize(obj) # More new special cases (that work with older protocols as # well): when __reduce__ returns a tuple with 4 or 5 items, # the 4th and 5th item should be iterators that provide list # items and dict items (as (key, value) tuples), or None. if listitems is not None: self._batch_appends(listitems) if dictitems is not None: self._batch_setitems(dictitems) if state is not None: save(state) write(BUILD) # Methods below this point are dispatched through the dispatch table dispatch = {} def save_none(self, obj): self.write(NONE) dispatch[NoneType] = save_none def save_bool(self, obj): if self.proto >= 2: self.write(obj and NEWTRUE or NEWFALSE) else: self.write(obj and TRUE or FALSE) dispatch[bool] = save_bool def save_int(self, obj, pack=struct.pack): if self.bin: # If the int is small enough to fit in a signed 4-byte 2's-comp # format, we can store it more efficiently than the general # case. # First one- and two-byte unsigned ints: if obj >= 0: if obj <= 0xff: self.write(BININT1 + chr(obj)) return if obj <= 0xffff: self.write("%c%c%c" % (BININT2, obj&0xff, obj>>8)) return # Next check for 4-byte signed ints: high_bits = obj >> 31 # note that Python shift sign-extends if high_bits == 0 or high_bits == -1: # All high bits are copies of bit 2**31, so the value # fits in a 4-byte signed int. self.write(BININT + pack("<i", obj)) return # Text pickle, or int too big to fit in signed 4-byte format. self.write(INT + repr(obj) + '\n') dispatch[IntType] = save_int def save_long(self, obj, pack=struct.pack): if self.proto >= 2: bytes = encode_long(obj) n = len(bytes) if n < 256: self.write(LONG1 + chr(n) + bytes) else: self.write(LONG4 + pack("<i", n) + bytes) return self.write(LONG + repr(obj) + '\n') dispatch[LongType] = save_long def save_float(self, obj, pack=struct.pack): if self.bin: self.write(BINFLOAT + pack('>d', obj)) else: self.write(FLOAT + repr(obj) + '\n') dispatch[FloatType] = save_float def save_string(self, obj, pack=struct.pack): if self.bin: n = len(obj) if n < 256: self.write(SHORT_BINSTRING + chr(n) + obj) else: self.write(BINSTRING + pack("<i", n) + obj) else: self.write(STRING + repr(obj) + '\n') self.memoize(obj) dispatch[StringType] = save_string def save_unicode(self, obj, pack=struct.pack): if self.bin: encoding = obj.encode('utf-8') n = len(encoding) self.write(BINUNICODE + pack("<i", n) + encoding) else: obj = obj.replace("\\", "\\u005c") obj = obj.replace("\n", "\\u000a") self.write(UNICODE + obj.encode('raw-unicode-escape') + '\n')Lines 1–500 of 1383. 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"""Create portable serialized representations of Python objects. See module cPickle for a (much) faster implementation. See module copy_reg for a mechanism for registering custom picklers. See module pickletools source for extensive comments. Classes: Pickler Unpickler Functions: dump(object, file) dumps(object) -> string load(file) -> object loads(string) -> object Misc variables: __version__ format_version compatible_formats """ __version__ = "$Revision: 38432 $" # Code version from types import * from copy_reg import dispatch_table from copy_reg import _extension_registry, _inverted_registry, _extension_cache import marshal import sys import struct import re __all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler", "Unpickler", "dump", "dumps", "load", "loads"] # These are purely informational; no code uses these. 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 "2.0", # Protocol 2 ] # Old format versions we can read # Keep in synch with cPickle. This is the highest protocol number we # know how to read. HIGHEST_PROTOCOL = 2 # Why use struct.pack() for pickling but marshal.loads() for # unpickling? struct.pack() is 40% faster than marshal.dumps(), but # marshal.loads() is twice as fast as struct.unpack()! mloads = marshal.loads class PickleError(Exception): """A common base class for the other pickling exceptions.""" pass class PicklingError(PickleError): """This exception is raised when an unpicklable object is passed to the dump() method. """ pass class UnpicklingError(PickleError): """This exception is raised when there is a problem unpickling an object, such as a security violation. Note that other exceptions may also be raised during unpickling, including (but not necessarily limited to) AttributeError, EOFError, ImportError, and IndexError. """ pass # An instance of _Stop is raised by Unpickler.load_stop() in response to # the STOP opcode, passing the object that is the result of unpickling. class _Stop(Exception): def __init__(self, value): self.value = value # Jython has PyStringMap; it's a dict subclass with string keys try: from org.python.core import PyStringMap except ImportError: PyStringMap = None # UnicodeType may or may not be exported (normally imported from types) try: UnicodeType except NameError: UnicodeType = None # Pickle opcodes. See pickletools.py for extensive docs. The listing # here is in kind-of alphabetical order of 1-character pickle code. # pickletools groups them by purpose. MARK = '(' # push special markobject on stack STOP = '.' # every pickle ends with STOP POP = '0' # discard topmost stack item POP_MARK = '1' # discard stack top through topmost markobject DUP = '2' # duplicate top stack item FLOAT = 'F' # push float object; decimal string argument INT = 'I' # push integer or bool; decimal string argument BININT = 'J' # push four-byte signed int BININT1 = 'K' # push 1-byte unsigned int LONG = 'L' # push long; decimal string argument BININT2 = 'M' # push 2-byte unsigned int NONE = 'N' # push None PERSID = 'P' # push persistent object; id is taken from string arg BINPERSID = 'Q' # " " " ; " " " " stack REDUCE = 'R' # apply callable to argtuple, both on stack STRING = 'S' # push string; NL-terminated string argument BINSTRING = 'T' # push string; counted binary string argument SHORT_BINSTRING = 'U' # " " ; " " " " < 256 bytes UNICODE = 'V' # push Unicode string; raw-unicode-escaped'd argument BINUNICODE = 'X' # " " " ; counted UTF-8 string argument APPEND = 'a' # append stack top to list below it BUILD = 'b' # call __setstate__ or __dict__.update() GLOBAL = 'c' # push self.find_class(modname, name); 2 string args DICT = 'd' # build a dict from stack items EMPTY_DICT = '}' # push empty dict APPENDS = 'e' # extend list on stack by topmost stack slice GET = 'g' # push item from memo on stack; index is string arg BINGET = 'h' # " " " " " " ; " " 1-byte arg INST = 'i' # build & push class instance LONG_BINGET = 'j' # push item from memo on stack; index is 4-byte arg LIST = 'l' # build list from topmost stack items EMPTY_LIST = ']' # push empty list OBJ = 'o' # build & push class instance PUT = 'p' # store stack top in memo; index is string arg BINPUT = 'q' # " " " " " ; " " 1-byte arg LONG_BINPUT = 'r' # " " " " " ; " " 4-byte arg SETITEM = 's' # add key+value pair to dict TUPLE = 't' # build tuple from topmost stack items EMPTY_TUPLE = ')' # push empty tuple SETITEMS = 'u' # modify dict by adding topmost key+value pairs BINFLOAT = 'G' # push float; arg is 8-byte float encoding TRUE = 'I01\n' # not an opcode; see INT docs in pickletools.py FALSE = 'I00\n' # not an opcode; see INT docs in pickletools.py # Protocol 2 PROTO = '\x80' # identify pickle protocol NEWOBJ = '\x81' # build object by applying cls.__new__ to argtuple EXT1 = '\x82' # push object from extension registry; 1-byte index EXT2 = '\x83' # ditto, but 2-byte index EXT4 = '\x84' # ditto, but 4-byte index TUPLE1 = '\x85' # build 1-tuple from stack top TUPLE2 = '\x86' # build 2-tuple from two topmost stack items TUPLE3 = '\x87' # build 3-tuple from three topmost stack items NEWTRUE = '\x88' # push True NEWFALSE = '\x89' # push False LONG1 = '\x8a' # push long from < 256 bytes LONG4 = '\x8b' # push really big long _tuplesize2code = [EMPTY_TUPLE, TUPLE1, TUPLE2, TUPLE3] __all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$",x)]) del x # Pickling machinery class Pickler: def __init__(self, file, protocol=None): """This takes a file-like object for writing a pickle data stream. The optional protocol argument tells the pickler to use the given protocol; supported protocols are 0, 1, 2. The default protocol is 0, to be backwards compatible. (Protocol 0 is the only protocol that can be written to a file opened in text mode and read back successfully. When using a protocol higher than 0, make sure the file is opened in binary mode, both when pickling and unpickling.) Protocol 1 is more efficient than protocol 0; protocol 2 is more efficient than protocol 1. Specifying a negative protocol version selects the highest protocol version supported. The higher the protocol used, the more recent the version of Python needed to read the pickle produced. The file parameter must have a write() method that accepts a single string argument. It can thus be an open file object, a StringIO object, or any other custom object that meets this interface. """ if protocol is None: protocol = 0 if protocol < 0: protocol = HIGHEST_PROTOCOL elif not 0 <= protocol <= HIGHEST_PROTOCOL: raise ValueError("pickle protocol must be <= %d" % HIGHEST_PROTOCOL) self.write = file.write self.memo = {} self.proto = int(protocol) self.bin = protocol >= 1 self.fast = 0 def clear_memo(self): """Clears the pickler's "memo". The memo is the data structure that remembers which objects the pickler has already seen, so that shared or recursive objects are pickled by reference and not by value. This method is useful when re-using picklers. """ self.memo.clear() def dump(self, obj): """Write a pickled representation of obj to the open file.""" if self.proto >= 2: self.write(PROTO + chr(self.proto)) self.save(obj) self.write(STOP) def memoize(self, obj): """Store an object in the memo.""" # The Pickler memo is a dictionary mapping object ids to 2-tuples # that contain the Unpickler memo key and the object being memoized. # The memo key is written to the pickle and will become # the key in the Unpickler's memo. The object is stored in the # Pickler memo so that transient objects are kept alive during # pickling. # The use of the Unpickler memo length as the memo key is just a # convention. The only requirement is that the memo values be unique. # But there appears no advantage to any other scheme, and this # scheme allows the Unpickler memo to be implemented as a plain (but # growable) array, indexed by memo key. if self.fast: return assert id(obj) not in self.memo memo_len = len(self.memo) self.write(self.put(memo_len)) self.memo[id(obj)] = memo_len, obj # Return a PUT (BINPUT, LONG_BINPUT) opcode string, with argument i. def put(self, i, pack=struct.pack): if self.bin: if i < 256: return BINPUT + chr(i) else: return LONG_BINPUT + pack("<i", i) return PUT + repr(i) + '\n' # Return a GET (BINGET, LONG_BINGET) opcode string, with argument i. def get(self, i, pack=struct.pack): if self.bin: if i < 256: return BINGET + chr(i) else: return LONG_BINGET + pack("<i", i) return GET + repr(i) + '\n' 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: self.save_global(obj) return # Check copy_reg.dispatch_table reduce = dispatch_table.get(t) if reduce: rv = reduce(obj) else: # Check for a __reduce_ex__ method, fall back to __reduce__ reduce = getattr(obj, "__reduce_ex__", None) if reduce: rv = reduce(self.proto) else: reduce = getattr(obj, "__reduce__", None) if reduce: rv = reduce() else: raise PicklingError("Can't pickle %r object: %r" % (t.__name__, obj)) # 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 an appropriately sized tuple l = len(rv) if not (2 <= l <= 5): raise PicklingError("Tuple returned by %s must have " "two to five elements" % reduce) # Save the reduce() output and finally memoize the object self.save_reduce(obj=obj, *rv) 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) self.write(BINPERSID) else: self.write(PERSID + str(pid) + '\n') def save_reduce(self, func, args, state=None, listitems=None, dictitems=None, obj=None): # This API is called by some subclasses # Assert that args is a tuple or None if not isinstance(args, TupleType): 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 # Protocol 2 special case: if func's name is __newobj__, use NEWOBJ if self.proto >= 2 and getattr(func, "__name__", "") == "__newobj__": # A __reduce__ implementation can direct protocol 2 to # use the more efficient NEWOBJ opcode, while still # allowing protocol 0 and 1 to work normally. For this to # work, the function returned by __reduce__ should be # called __newobj__, and its first argument should be a # new-style class. The implementation for __newobj__ # should be as follows, although pickle has no way to # verify this: # # def __newobj__(cls, *args): # return cls.__new__(cls, *args) # # Protocols 0 and 1 will pickle a reference to __newobj__, # while protocol 2 (and above) will pickle a reference to # cls, the remaining args tuple, and the NEWOBJ code, # which calls cls.__new__(cls, *args) at unpickling time # (see load_newobj below). If __reduce__ returns a # three-tuple, the state from the third tuple item will be # pickled regardless of the protocol, calling __setstate__ # at unpickling time (see load_build below). # # Note that no standard __newobj__ implementation exists; # you have to provide your own. This is to enforce # compatibility with Python 2.2 (pickles written using # protocol 0 or 1 in Python 2.3 should be unpicklable by # Python 2.2). cls = args[0] if not hasattr(cls, "__new__"): raise PicklingError( "args[0] from __newobj__ args has no __new__") if obj is not None and cls is not obj.__class__: raise PicklingError( "args[0] from __newobj__ args has the wrong class") args = args[1:] save(cls) save(args) write(NEWOBJ) else: save(func) save(args) write(REDUCE) if obj is not None: self.memoize(obj) # More new special cases (that work with older protocols as # well): when __reduce__ returns a tuple with 4 or 5 items, # the 4th and 5th item should be iterators that provide list # items and dict items (as (key, value) tuples), or None. if listitems is not None: self._batch_appends(listitems) if dictitems is not None: self._batch_setitems(dictitems) if state is not None: save(state) write(BUILD) # Methods below this point are dispatched through the dispatch table dispatch = {} def save_none(self, obj): self.write(NONE) dispatch[NoneType] = save_none def save_bool(self, obj): if self.proto >= 2: self.write(obj and NEWTRUE or NEWFALSE) else: self.write(obj and TRUE or FALSE) dispatch[bool] = save_bool def save_int(self, obj, pack=struct.pack): if self.bin: # If the int is small enough to fit in a signed 4-byte 2's-comp # format, we can store it more efficiently than the general # case. # First one- and two-byte unsigned ints: if obj >= 0: if obj <= 0xff: self.write(BININT1 + chr(obj)) return if obj <= 0xffff: self.write("%c%c%c" % (BININT2, obj&0xff, obj>>8)) return # Next check for 4-byte signed ints: high_bits = obj >> 31 # note that Python shift sign-extends if high_bits == 0 or high_bits == -1: # All high bits are copies of bit 2**31, so the value # fits in a 4-byte signed int. self.write(BININT + pack("<i", obj)) return # Text pickle, or int too big to fit in signed 4-byte format. self.write(INT + repr(obj) + '\n') dispatch[IntType] = save_int def save_long(self, obj, pack=struct.pack): if self.proto >= 2: bytes = encode_long(obj) n = len(bytes) if n < 256: self.write(LONG1 + chr(n) + bytes) else: self.write(LONG4 + pack("<i", n) + bytes) return self.write(LONG + repr(obj) + '\n') dispatch[LongType] = save_long def save_float(self, obj, pack=struct.pack): if self.bin: self.write(BINFLOAT + pack('>d', obj)) else: self.write(FLOAT + repr(obj) + '\n') dispatch[FloatType] = save_float def save_string(self, obj, pack=struct.pack): if self.bin: n = len(obj) if n < 256: self.write(SHORT_BINSTRING + chr(n) + obj) else: self.write(BINSTRING + pack("<i", n) + obj) else: self.write(STRING + repr(obj) + '\n') self.memoize(obj) dispatch[StringType] = save_string def save_unicode(self, obj, pack=struct.pack): if self.bin: encoding = obj.encode('utf-8') n = len(encoding) self.write(BINUNICODE + pack("<i", n) + encoding) else: obj = obj.replace("\\", "\\u005c") obj = obj.replace("\n", "\\u000a") self.write(UNICODE + obj.encode('raw-unicode-escape') + '\n')