| """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__ = "$Revision$" # 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 |
| import warnings |
| |
| __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, bin=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 not None and bin is not None: |
| raise ValueError, "can't specify both 'protocol' and 'bin'" |
| if bin is not None: |
| warnings.warn("The 'bin' argument to Pickler() is deprecated", |
| PendingDeprecationWarning) |
| protocol = bin |
| 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 + `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 + `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 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 |
| |
| # 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 + `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 + `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 + `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 + `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') |
| self.memoize(obj) |
| dispatch[UnicodeType] = save_unicode |
| |
| if StringType == UnicodeType: |
| # This is true for Jython |
| def save_string(self, obj, pack=struct.pack): |
| unicode = obj.isunicode() |
| |
| if self.bin: |
| if unicode: |
| obj = obj.encode("utf-8") |
| l = len(obj) |
| if l < 256 and not unicode: |
| self.write(SHORT_BINSTRING + chr(l) + obj) |
| else: |
| s = pack("<i", l) |
| if unicode: |
| self.write(BINUNICODE + s + obj) |
| else: |
| self.write(BINSTRING + s + obj) |
| else: |
| if unicode: |
| obj = obj.replace("\\", "\\u005c") |
| obj = obj.replace("\n", "\\u000a") |
| obj = obj.encode('raw-unicode-escape') |
| self.write(UNICODE + obj + '\n') |
| else: |
| self.write(STRING + `obj` + '\n') |
| self.memoize(obj) |
| dispatch[StringType] = save_string |
| |
| def save_tuple(self, obj): |
| write = self.write |
| proto = self.proto |
| |
| n = len(obj) |
| if n == 0: |
| if proto: |
| write(EMPTY_TUPLE) |
| else: |
| write(MARK + TUPLE) |
| return |
| |
| save = self.save |
| memo = self.memo |
| if n <= 3 and proto >= 2: |
| for element in obj: |
| save(element) |
| # Subtle. Same as in the big comment below. |
| if id(obj) in memo: |
| get = self.get(memo[id(obj)][0]) |
| write(POP * n + get) |
| else: |
| write(_tuplesize2code[n]) |
| self.memoize(obj) |
| return |
| |
| # proto 0 or proto 1 and tuple isn't empty, or proto > 1 and tuple |
| # has more than 3 elements. |
| write(MARK) |
| for element in obj: |
| save(element) |
| |
| if id(obj) in memo: |
| # Subtle. d was not in memo when we entered save_tuple(), so |
| # the process of saving the tuple's elements must have saved |
| # the tuple itself: the tuple is recursive. The proper action |
| # now is to throw away everything we put on the stack, and |
| # simply GET the tuple (it's already constructed). This check |
| # could have been done in the "for element" loop instead, but |
| # recursive tuples are a rare thing. |
| get = self.get(memo[id(obj)][0]) |
| if proto: |
| write(POP_MARK + get) |
| else: # proto 0 -- POP_MARK not available |
| write(POP * (n+1) + get) |
| return |
| |
| # No recursion. |
| self.write(TUPLE) |
| self.memoize(obj) |
| |
| dispatch[TupleType] = save_tuple |
| |
| # save_empty_tuple() isn't used by anything in Python 2.3. However, I |
| # found a Pickler subclass in Zope3 that calls it, so it's not harmless |
| # to remove it. |
| def save_empty_tuple(self, obj): |
| self.write(EMPTY_TUPLE) |
| |
| def save_list(self, obj): |
| write = self.write |
| |
| if self.bin: |
| write(EMPTY_LIST) |
| else: # proto 0 -- can't use EMPTY_LIST |
| write(MARK + LIST) |
| |
| self.memoize(obj) |
| self._batch_appends(iter(obj)) |
| |
| dispatch[ListType] = save_list |
| |
| # Keep in synch with cPickle's BATCHSIZE. Nothing will break if it gets |
| # out of synch, though. |
| _BATCHSIZE = 1000 |
| |
| def _batch_appends(self, items): |
| # Helper to batch up APPENDS sequences |
| save = self.save |
| write = self.write |
| |
| if not self.bin: |
| for x in items: |
| save(x) |
| write(APPEND) |
| return |
| |
| r = xrange(self._BATCHSIZE) |
| while items is not None: |
| tmp = [] |
| for i in r: |
| try: |
| x = items.next() |
| tmp.append(x) |
| except StopIteration: |
| items = None |
| break |
| n = len(tmp) |
| if n > 1: |
| write(MARK) |
| for x in tmp: |
| save(x) |
| write(APPENDS) |
| elif n: |
| save(tmp[0]) |
| write(APPEND) |
| # else tmp is empty, and we're done |
| |
| def save_dict(self, obj): |
| write = self.write |
| |
| if self.bin: |
| write(EMPTY_DICT) |
| else: # proto 0 -- can't use EMPTY_DICT |
| write(MARK + DICT) |
| |
| self.memoize(obj) |
| self._batch_setitems(obj.iteritems()) |
| |
| dispatch[DictionaryType] = save_dict |
| if not PyStringMap is None: |
| dispatch[PyStringMap] = save_dict |
| |
| def _batch_setitems(self, items): |
| # Helper to batch up SETITEMS sequences; proto >= 1 only |
| save = self.save |
| write = self.write |
| |
| if not self.bin: |
| for k, v in items: |
| save(k) |
| save(v) |
| write(SETITEM) |
| return |
| |
| r = xrange(self._BATCHSIZE) |
| while items is not None: |
| tmp = [] |
| for i in r: |
| try: |
| tmp.append(items.next()) |
| except StopIteration: |
| items = None |
| break |
| n = len(tmp) |
| if n > 1: |
| write(MARK) |
| for k, v in tmp: |
| save(k) |
| save(v) |
| write(SETITEMS) |
| elif n: |
| k, v = tmp[0] |
| save(k) |
| save(v) |
| write(SETITEM) |
| # else tmp is empty, and we're done |
| |
| def save_inst(self, obj): |
| cls = obj.__class__ |
| |
| memo = self.memo |
| write = self.write |
| save = self.save |
| |
| if hasattr(obj, '__getinitargs__'): |
| args = obj.__getinitargs__() |
| len(args) # XXX Assert it's a sequence |
| _keep_alive(args, memo) |
| else: |
| args = () |
| |
| write(MARK) |
| |
| if self.bin: |
| save(cls) |
| for arg in args: |
| save(arg) |
| write(OBJ) |
| else: |
| for arg in args: |
| save(arg) |
| write(INST + cls.__module__ + '\n' + cls.__name__ + '\n') |
| |
| self.memoize(obj) |
| |
| try: |
| getstate = obj.__getstate__ |
| except AttributeError: |
| stuff = obj.__dict__ |
| else: |
| stuff = getstate() |
| _keep_alive(stuff, memo) |
| save(stuff) |
| write(BUILD) |
| |
| dispatch[InstanceType] = save_inst |
| |
| def save_global(self, obj, name=None, pack=struct.pack): |
| write = self.write |
| memo = self.memo |
| |
| if name is None: |
| name = obj.__name__ |
| |
| module = getattr(obj, "__module__", None) |
| if module is None: |
| module = whichmodule(obj, name) |
| |
| try: |
| __import__(module) |
| mod = sys.modules[module] |
| klass = getattr(mod, name) |
| except (ImportError, KeyError, AttributeError): |
| raise PicklingError( |
| "Can't pickle %r: it's not found as %s.%s" % |
| (obj, module, name)) |
| else: |
| if klass is not obj: |
| raise PicklingError( |
| "Can't pickle %r: it's not the same object as %s.%s" % |
| (obj, module, name)) |
| |
| if self.proto >= 2: |
| code = _extension_registry.get((module, name)) |
| if code: |
| assert code > 0 |
| if code <= 0xff: |
| write(EXT1 + chr(code)) |
| elif code <= 0xffff: |
| write("%c%c%c" % (EXT2, code&0xff, code>>8)) |
| else: |
| write(EXT4 + pack("<i", code)) |
| return |
| |
| write(GLOBAL + module + '\n' + name + '\n') |
| self.memoize(obj) |
| |
| dispatch[ClassType] = save_global |
| dispatch[FunctionType] = save_global |
| dispatch[BuiltinFunctionType] = save_global |
| dispatch[TypeType] = save_global |
| |
| # Pickling helpers |
| |
| def _keep_alive(x, memo): |
| """Keeps a reference to the object x in the memo. |
| |
| Because we remember objects by their id, we have |
| to assure that possibly temporary objects are kept |
| alive by referencing them. |
| We store a reference at the id of the memo, which should |
| normally not be used unless someone tries to deepcopy |
| the memo itself... |
| """ |
| try: |
| memo[id(memo)].append(x) |
| except KeyError: |
| # aha, this is the first one :-) |
| memo[id(memo)]=[x] |
| |
| |
| # A cache for whichmodule(), mapping a function object to the name of |
| # the module in which the function was found. |
| |
| classmap = {} # called classmap for backwards compatibility |
| |
| def whichmodule(func, funcname): |
| """Figure out the module in which a function occurs. |
| |
| Search sys.modules for the module. |
| Cache in classmap. |
| Return a module name. |
| If the function cannot be found, return "__main__". |
| """ |
| # Python functions should always get an __module__ from their globals. |
| mod = getattr(func, "__module__", None) |
| if mod is not None: |
| return mod |
| if func in classmap: |
| return classmap[func] |
| |
| for name, module in sys.modules.items(): |
| if module is None: |
| continue # skip dummy package entries |
| if name != '__main__' and getattr(module, funcname, None) is func: |
| break |
| else: |
| name = '__main__' |
| classmap[func] = name |
| return name |
| |
| |
| # Unpickling machinery |
| |
| class Unpickler: |
| |
| def __init__(self, file): |
| """This takes a file-like object for reading a pickle data stream. |
| |
| The protocol version of the pickle is detected automatically, so no |
| proto argument is needed. |
| |
| The file-like object must have two methods, a read() method that |
| takes an integer argument, and a readline() method that requires no |
| arguments. Both methods should return a string. Thus file-like |
| object can be a file object opened for reading, a StringIO object, |
| or any other custom object that meets this interface. |
| """ |
| self.readline = file.readline |
| self.read = file.read |
| self.memo = {} |
| |
| def load(self): |
| """Read a pickled object representation from the open file. |
| |
| Return the reconstituted object hierarchy specified in the file. |
| """ |
| self.mark = object() # any new unique object |
| self.stack = [] |
| self.append = self.stack.append |
| read = self.read |
| dispatch = self.dispatch |
| try: |
| while 1: |
| key = read(1) |
| dispatch[key](self) |
| except _Stop, stopinst: |
| return stopinst.value |
| |
| # Return largest index k such that self.stack[k] is self.mark. |
| # If the stack doesn't contain a mark, eventually raises IndexError. |
| # This could be sped by maintaining another stack, of indices at which |
| # the mark appears. For that matter, the latter stack would suffice, |
| # and we wouldn't need to push mark objects on self.stack at all. |
| # Doing so is probably a good thing, though, since if the pickle is |
| # corrupt (or hostile) we may get a clue from finding self.mark embedded |
| # in unpickled objects. |
| def marker(self): |
| stack = self.stack |
| mark = self.mark |
| k = len(stack)-1 |
| while stack[k] is not mark: k = k-1 |
| return k |
| |
| dispatch = {} |
| |
| def load_eof(self): |
| raise EOFError |
| dispatch[''] = load_eof |
| |
| def load_proto(self): |
| proto = ord(self.read(1)) |
| if not 0 <= proto <= 2: |
| raise ValueError, "unsupported pickle protocol: %d" % proto |
| dispatch[PROTO] = load_proto |
| |
| def load_persid(self): |
| pid = self.readline()[:-1] |
| self.append(self.persistent_load(pid)) |
| dispatch[PERSID] = load_persid |
| |
| def load_binpersid(self): |
| pid = self.stack.pop() |
| self.append(self.persistent_load(pid)) |
| dispatch[BINPERSID] = load_binpersid |
| |
| def load_none(self): |
| self.append(None) |
| dispatch[NONE] = load_none |
| |
| def load_false(self): |
| self.append(False) |
| dispatch[NEWFALSE] = load_false |
| |
| def load_true(self): |
| self.append(True) |
| dispatch[NEWTRUE] = load_true |
| |
| def load_int(self): |
| data = self.readline() |
| if data == FALSE[1:]: |
| val = False |
| elif data == TRUE[1:]: |
| val = True |
| else: |
| try: |
| val = int(data) |
| except ValueError: |
| val = long(data) |
| self.append(val) |
| dispatch[INT] = load_int |
| |
| def load_binint(self): |
| self.append(mloads('i' + self.read(4))) |
| dispatch[BININT] = load_binint |
| |
| def load_binint1(self): |
| self.append(ord(self.read(1))) |
| dispatch[BININT1] = load_binint1 |
| |
| def load_binint2(self): |
| self.append(mloads('i' + self.read(2) + '\000\000')) |
| dispatch[BININT2] = load_binint2 |
| |
| def load_long(self): |
| self.append(long(self.readline()[:-1], 0)) |
| dispatch[LONG] = load_long |
| |
| def load_long1(self): |
| n = ord(self.read(1)) |
| bytes = self.read(n) |
| self.append(decode_long(bytes)) |
| dispatch[LONG1] = load_long1 |
| |
| def load_long4(self): |
| n = mloads('i' + self.read(4)) |
| bytes = self.read(n) |
| self.append(decode_long(bytes)) |
| dispatch[LONG4] = load_long4 |
| |
| def load_float(self): |
| self.append(float(self.readline()[:-1])) |
| dispatch[FLOAT] = load_float |
| |
| def load_binfloat(self, unpack=struct.unpack): |
| self.append(unpack('>d', self.read(8))[0]) |
| dispatch[BINFLOAT] = load_binfloat |
| |
| def load_string(self): |
| rep = self.readline()[:-1] |
| for q in "\"'": # double or single quote |
| if rep.startswith(q): |
| if not rep.endswith(q): |
| raise ValueError, "insecure string pickle" |
| rep = rep[len(q):-len(q)] |
| break |
| else: |
| raise ValueError, "insecure string pickle" |
| self.append(rep.decode("string-escape")) |
| dispatch[STRING] = load_string |
| |
| def load_binstring(self): |
| len = mloads('i' + self.read(4)) |
| self.append(self.read(len)) |
| dispatch[BINSTRING] = load_binstring |
| |
| def load_unicode(self): |
| self.append(unicode(self.readline()[:-1],'raw-unicode-escape')) |
| dispatch[UNICODE] = load_unicode |
| |
| def load_binunicode(self): |
| len = mloads('i' + self.read(4)) |
| self.append(unicode(self.read(len),'utf-8')) |
| dispatch[BINUNICODE] = load_binunicode |
| |
| def load_short_binstring(self): |
| len = ord(self.read(1)) |
| self.append(self.read(len)) |
| dispatch[SHORT_BINSTRING] = load_short_binstring |
| |
| def load_tuple(self): |
| k = self.marker() |
| self.stack[k:] = [tuple(self.stack[k+1:])] |
| dispatch[TUPLE] = load_tuple |
| |
| def load_empty_tuple(self): |
| self.stack.append(()) |
| dispatch[EMPTY_TUPLE] = load_empty_tuple |
| |
| def load_tuple1(self): |
| self.stack[-1] = (self.stack[-1],) |
| dispatch[TUPLE1] = load_tuple1 |
| |
| def load_tuple2(self): |
| self.stack[-2:] = [(self.stack[-2], self.stack[-1])] |
| dispatch[TUPLE2] = load_tuple2 |
| |
| def load_tuple3(self): |
| self.stack[-3:] = [(self.stack[-3], self.stack[-2], self.stack[-1])] |
| dispatch[TUPLE3] = load_tuple3 |
| |
| def load_empty_list(self): |
| self.stack.append([]) |
| dispatch[EMPTY_LIST] = load_empty_list |
| |
| def load_empty_dictionary(self): |
| self.stack.append({}) |
| dispatch[EMPTY_DICT] = load_empty_dictionary |
| |
| def load_list(self): |
| k = self.marker() |
| self.stack[k:] = [self.stack[k+1:]] |
| dispatch[LIST] = load_list |
| |
| def load_dict(self): |
| k = self.marker() |
| d = {} |
| items = self.stack[k+1:] |
| for i in range(0, len(items), 2): |
| key = items[i] |
| value = items[i+1] |
| d[key] = value |
| self.stack[k:] = [d] |
| dispatch[DICT] = load_dict |
| |
| # INST and OBJ differ only in how they get a class object. It's not |
| # only sensible to do the rest in a common routine, the two routines |
| # previously diverged and grew different bugs. |
| # klass is the class to instantiate, and k points to the topmost mark |
| # object, following which are the arguments for klass.__init__. |
| def _instantiate(self, klass, k): |
| args = tuple(self.stack[k+1:]) |
| del self.stack[k:] |
| instantiated = 0 |
| if (not args and |
| type(klass) is ClassType and |
| not hasattr(klass, "__getinitargs__")): |
| try: |
| value = _EmptyClass() |
| value.__class__ = klass |
| instantiated = 1 |
| except RuntimeError: |
| # In restricted execution, assignment to inst.__class__ is |
| # prohibited |
| pass |
| if not instantiated: |
| try: |
| value = klass(*args) |
| except TypeError, err: |
| raise TypeError, "in constructor for %s: %s" % ( |
| klass.__name__, str(err)), sys.exc_info()[2] |
| self.append(value) |
| |
| def load_inst(self): |
| module = self.readline()[:-1] |
| name = self.readline()[:-1] |
| klass = self.find_class(module, name) |
| self._instantiate(klass, self.marker()) |
| dispatch[INST] = load_inst |
| |
| def load_obj(self): |
| # Stack is ... markobject classobject arg1 arg2 ... |
| k = self.marker() |
| klass = self.stack.pop(k+1) |
| self._instantiate(klass, k) |
| dispatch[OBJ] = load_obj |
| |
| def load_newobj(self): |
| args = self.stack.pop() |
| cls = self.stack[-1] |
| obj = cls.__new__(cls, *args) |
| self.stack[-1] = obj |
| dispatch[NEWOBJ] = load_newobj |
| |
| def load_global(self): |
| module = self.readline()[:-1] |
| name = self.readline()[:-1] |
| klass = self.find_class(module, name) |
| self.append(klass) |
| dispatch[GLOBAL] = load_global |
| |
| def load_ext1(self): |
| code = ord(self.read(1)) |
| self.get_extension(code) |
| dispatch[EXT1] = load_ext1 |
| |
| def load_ext2(self): |
| code = mloads('i' + self.read(2) + '\000\000') |
| self.get_extension(code) |
| dispatch[EXT2] = load_ext2 |
| |
| def load_ext4(self): |
| code = mloads('i' + self.read(4)) |
| self.get_extension(code) |
| dispatch[EXT4] = load_ext4 |
| |
| def get_extension(self, code): |
| nil = [] |
| obj = _extension_cache.get(code, nil) |
| if obj is not nil: |
| self.append(obj) |
| return |
| key = _inverted_registry.get(code) |
| if not key: |
| raise ValueError("unregistered extension code %d" % code) |
| obj = self.find_class(*key) |
| _extension_cache[code] = obj |
| self.append(obj) |
| |
| def find_class(self, module, name): |
| # Subclasses may override this |
| __import__(module) |
| mod = sys.modules[module] |
| klass = getattr(mod, name) |
| return klass |
| |
| def load_reduce(self): |
| stack = self.stack |
| args = stack.pop() |
| func = stack[-1] |
| if args is None: |
| # A hack for Jim Fulton's ExtensionClass, now deprecated |
| warnings.warn("__basicnew__ special case is deprecated", |
| DeprecationWarning) |
| value = func.__basicnew__() |
| else: |
| value = func(*args) |
| stack[-1] = value |
| dispatch[REDUCE] = load_reduce |
| |
| def load_pop(self): |
| del self.stack[-1] |
| dispatch[POP] = load_pop |
| |
| def load_pop_mark(self): |
| k = self.marker() |
| del self.stack[k:] |
| dispatch[POP_MARK] = load_pop_mark |
| |
| def load_dup(self): |
| self.append(self.stack[-1]) |
| dispatch[DUP] = load_dup |
| |
| def load_get(self): |
| self.append(self.memo[self.readline()[:-1]]) |
| dispatch[GET] = load_get |
| |
| def load_binget(self): |
| i = ord(self.read(1)) |
| self.append(self.memo[`i`]) |
| dispatch[BINGET] = load_binget |
| |
| def load_long_binget(self): |
| i = mloads('i' + self.read(4)) |
| self.append(self.memo[`i`]) |
| dispatch[LONG_BINGET] = load_long_binget |
| |
| def load_put(self): |
| self.memo[self.readline()[:-1]] = self.stack[-1] |
| dispatch[PUT] = load_put |
| |
| def load_binput(self): |
| i = ord(self.read(1)) |
| self.memo[`i`] = self.stack[-1] |
| dispatch[BINPUT] = load_binput |
| |
| def load_long_binput(self): |
| i = mloads('i' + self.read(4)) |
| self.memo[`i`] = self.stack[-1] |
| dispatch[LONG_BINPUT] = load_long_binput |
| |
| def load_append(self): |
| stack = self.stack |
| value = stack.pop() |
| list = stack[-1] |
| list.append(value) |
| dispatch[APPEND] = load_append |
| |
| def load_appends(self): |
| stack = self.stack |
| mark = self.marker() |
| list = stack[mark - 1] |
| list.extend(stack[mark + 1:]) |
| del stack[mark:] |
| dispatch[APPENDS] = load_appends |
| |
| def load_setitem(self): |
| stack = self.stack |
| value = stack.pop() |
| key = stack.pop() |
| dict = stack[-1] |
| dict[key] = value |
| dispatch[SETITEM] = load_setitem |
| |
| def load_setitems(self): |
| stack = self.stack |
| mark = self.marker() |
| dict = stack[mark - 1] |
| for i in range(mark + 1, len(stack), 2): |
| dict[stack[i]] = stack[i + 1] |
| |
| del stack[mark:] |
| dispatch[SETITEMS] = load_setitems |
| |
| def load_build(self): |
| stack = self.stack |
| state = stack.pop() |
| inst = stack[-1] |
| setstate = getattr(inst, "__setstate__", None) |
| if setstate: |
| setstate(state) |
| return |
| slotstate = None |
| if isinstance(state, tuple) and len(state) == 2: |
| state, slotstate = state |
| if state: |
| try: |
| inst.__dict__.update(state) |
| except RuntimeError: |
| # XXX In restricted execution, the instance's __dict__ |
| # is not accessible. Use the old way of unpickling |
| # the instance variables. This is a semantic |
| # difference when unpickling in restricted |
| # vs. unrestricted modes. |
| # Note, however, that cPickle has never tried to do the |
| # .update() business, and always uses |
| # PyObject_SetItem(inst.__dict__, key, value) in a |
| # loop over state.items(). |
| for k, v in state.items(): |
| setattr(inst, k, v) |
| if slotstate: |
| for k, v in slotstate.items(): |
| setattr(inst, k, v) |
| dispatch[BUILD] = load_build |
| |
| def load_mark(self): |
| self.append(self.mark) |
| dispatch[MARK] = load_mark |
| |
| def load_stop(self): |
| value = self.stack.pop() |
| raise _Stop(value) |
| dispatch[STOP] = load_stop |
| |
| # Helper class for load_inst/load_obj |
| |
| class _EmptyClass: |
| pass |
| |
| # Encode/decode longs in linear time. |
| |
| import binascii as _binascii |
| |
| def encode_long(x): |
| r"""Encode a long to a two's complement little-endian binary string. |
| Note that 0L is a special case, returning an empty string, to save a |
| byte in the LONG1 pickling context. |
| |
| >>> encode_long(0L) |
| '' |
| >>> encode_long(255L) |
| '\xff\x00' |
| >>> encode_long(32767L) |
| '\xff\x7f' |
| >>> encode_long(-256L) |
| '\x00\xff' |
| >>> encode_long(-32768L) |
| '\x00\x80' |
| >>> encode_long(-128L) |
| '\x80' |
| >>> encode_long(127L) |
| '\x7f' |
| >>> |
| """ |
| |
| if x == 0: |
| return '' |
| if x > 0: |
| ashex = hex(x) |
| assert ashex.startswith("0x") |
| njunkchars = 2 + ashex.endswith('L') |
| nibbles = len(ashex) - njunkchars |
| if nibbles & 1: |
| # need an even # of nibbles for unhexlify |
| ashex = "0x0" + ashex[2:] |
| elif int(ashex[2], 16) >= 8: |
| # "looks negative", so need a byte of sign bits |
| ashex = "0x00" + ashex[2:] |
| else: |
| # Build the 256's-complement: (1L << nbytes) + x. The trick is |
| # to find the number of bytes in linear time (although that should |
| # really be a constant-time task). |
| ashex = hex(-x) |
| assert ashex.startswith("0x") |
| njunkchars = 2 + ashex.endswith('L') |
| nibbles = len(ashex) - njunkchars |
| if nibbles & 1: |
| # Extend to a full byte. |
| nibbles += 1 |
| nbits = nibbles * 4 |
| x += 1L << nbits |
| assert x > 0 |
| ashex = hex(x) |
| njunkchars = 2 + ashex.endswith('L') |
| newnibbles = len(ashex) - njunkchars |
| if newnibbles < nibbles: |
| ashex = "0x" + "0" * (nibbles - newnibbles) + ashex[2:] |
| if int(ashex[2], 16) < 8: |
| # "looks positive", so need a byte of sign bits |
| ashex = "0xff" + ashex[2:] |
| |
| if ashex.endswith('L'): |
| ashex = ashex[2:-1] |
| else: |
| ashex = ashex[2:] |
| assert len(ashex) & 1 == 0, (x, ashex) |
| binary = _binascii.unhexlify(ashex) |
| return binary[::-1] |
| |
| def decode_long(data): |
| r"""Decode a long from a two's complement little-endian binary string. |
| |
| >>> decode_long('') |
| 0L |
| >>> decode_long("\xff\x00") |
| 255L |
| >>> decode_long("\xff\x7f") |
| 32767L |
| >>> decode_long("\x00\xff") |
| -256L |
| >>> decode_long("\x00\x80") |
| -32768L |
| >>> decode_long("\x80") |
| -128L |
| >>> decode_long("\x7f") |
| 127L |
| """ |
| |
| nbytes = len(data) |
| if nbytes == 0: |
| return 0L |
| ashex = _binascii.hexlify(data[::-1]) |
| n = long(ashex, 16) # quadratic time before Python 2.3; linear now |
| if data[-1] >= '\x80': |
| n -= 1L << (nbytes * 8) |
| return n |
| |
| # Shorthands |
| |
| try: |
| from cStringIO import StringIO |
| except ImportError: |
| from StringIO import StringIO |
| |
| def dump(obj, file, protocol=None, bin=None): |
| Pickler(file, protocol, bin).dump(obj) |
| |
| def dumps(obj, protocol=None, bin=None): |
| file = StringIO() |
| Pickler(file, protocol, bin).dump(obj) |
| return file.getvalue() |
| |
| def load(file): |
| return Unpickler(file).load() |
| |
| def loads(str): |
| file = StringIO(str) |
| return Unpickler(file).load() |
| |
| # Doctest |
| |
| def _test(): |
| import doctest |
| return doctest.testmod() |
| |
| if __name__ == "__main__": |
| _test() |