"""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 | |
__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 hasattr(func, '__call__'): | |
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') | |
self.memoize(obj) | |
dispatch[UnicodeType] = save_unicode | |
if StringType is 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 + repr(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] | |
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[repr(i)]) | |
dispatch[BINGET] = load_binget | |
def load_long_binget(self): | |
i = mloads('i' + self.read(4)) | |
self.append(self.memo[repr(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[repr(i)] = self.stack[-1] | |
dispatch[BINPUT] = load_binput | |
def load_long_binput(self): | |
i = mloads('i' + self.read(4)) | |
self.memo[repr(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: | |
d = inst.__dict__ | |
try: | |
for k, v in state.iteritems(): | |
d[intern(k)] = v | |
# keys in state don't have to be strings | |
# don't blow up, but don't go out of our way | |
except TypeError: | |
d.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): | |
Pickler(file, protocol).dump(obj) | |
def dumps(obj, protocol=None): | |
file = StringIO() | |
Pickler(file, protocol).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() |