"""Create portable serialized representations of Python objects.
See module copyreg for a mechanism for registering custom picklers.
See module pickletools source for extensive comments.
from types import FunctionType
from copyreg import dispatch_table
from copyreg import _extension_registry, _inverted_registry, _extension_cache
from itertools import islice
from functools import partial
from struct import pack, unpack
__all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler",
"Unpickler", "dump", "dumps", "load", "loads"]
from _pickle import PickleBuffer
__all__.append("PickleBuffer")
_HAVE_PICKLE_BUFFER = True
_HAVE_PICKLE_BUFFER = False
# Shortcut for use in isinstance testing
bytes_types = (bytes, bytearray)
# These are purely informational; no code uses these.
format_version = "4.0" # 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
] # Old format versions we can read
# This is the highest protocol number we know how to read.
# The protocol we write by default. May be less than HIGHEST_PROTOCOL.
# Only bump this if the oldest still supported version of Python already
class PickleError(Exception):
"""A common base class for the other pickling exceptions."""
class PicklingError(PickleError):
"""This exception is raised when an unpicklable object is passed to the
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,
# 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.
def __init__(self, value):
# Jython has PyStringMap; it's a dict subclass with string keys
from org.python.core import PyStringMap
# 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 = b'(' # push special markobject on stack
STOP = b'.' # every pickle ends with STOP
POP = b'0' # discard topmost stack item
POP_MARK = b'1' # discard stack top through topmost markobject
DUP = b'2' # duplicate top stack item
FLOAT = b'F' # push float object; decimal string argument
INT = b'I' # push integer or bool; decimal string argument
BININT = b'J' # push four-byte signed int
BININT1 = b'K' # push 1-byte unsigned int
LONG = b'L' # push long; decimal string argument
BININT2 = b'M' # push 2-byte unsigned int
PERSID = b'P' # push persistent object; id is taken from string arg
BINPERSID = b'Q' # " " " ; " " " " stack
REDUCE = b'R' # apply callable to argtuple, both on stack
STRING = b'S' # push string; NL-terminated string argument
BINSTRING = b'T' # push string; counted binary string argument
SHORT_BINSTRING= b'U' # " " ; " " " " < 256 bytes
UNICODE = b'V' # push Unicode string; raw-unicode-escaped'd argument
BINUNICODE = b'X' # " " " ; counted UTF-8 string argument
APPEND = b'a' # append stack top to list below it
BUILD = b'b' # call __setstate__ or __dict__.update()
GLOBAL = b'c' # push self.find_class(modname, name); 2 string args
DICT = b'd' # build a dict from stack items
EMPTY_DICT = b'}' # push empty dict
APPENDS = b'e' # extend list on stack by topmost stack slice
GET = b'g' # push item from memo on stack; index is string arg
BINGET = b'h' # " " " " " " ; " " 1-byte arg
INST = b'i' # build & push class instance
LONG_BINGET = b'j' # push item from memo on stack; index is 4-byte arg
LIST = b'l' # build list from topmost stack items
EMPTY_LIST = b']' # push empty list
OBJ = b'o' # build & push class instance
PUT = b'p' # store stack top in memo; index is string arg
BINPUT = b'q' # " " " " " ; " " 1-byte arg
LONG_BINPUT = b'r' # " " " " " ; " " 4-byte arg
SETITEM = b's' # add key+value pair to dict
TUPLE = b't' # build tuple from topmost stack items
EMPTY_TUPLE = b')' # push empty tuple
SETITEMS = b'u' # modify dict by adding topmost key+value pairs
BINFLOAT = b'G' # push float; arg is 8-byte float encoding
TRUE = b'I01\n' # not an opcode; see INT docs in pickletools.py
FALSE = b'I00\n' # not an opcode; see INT docs in pickletools.py
PROTO = b'\x80' # identify pickle protocol
NEWOBJ = b'\x81' # build object by applying cls.__new__ to argtuple
EXT1 = b'\x82' # push object from extension registry; 1-byte index
EXT2 = b'\x83' # ditto, but 2-byte index
EXT4 = b'\x84' # ditto, but 4-byte index
TUPLE1 = b'\x85' # build 1-tuple from stack top
TUPLE2 = b'\x86' # build 2-tuple from two topmost stack items
TUPLE3 = b'\x87' # build 3-tuple from three topmost stack items
NEWTRUE = b'\x88' # push True
NEWFALSE = b'\x89' # push False
LONG1 = b'\x8a' # push long from < 256 bytes
LONG4 = b'\x8b' # push really big long
_tuplesize2code = [EMPTY_TUPLE, TUPLE1, TUPLE2, TUPLE3]
# Protocol 3 (Python 3.x)
BINBYTES = b'B' # push bytes; counted binary string argument
SHORT_BINBYTES = b'C' # " " ; " " " " < 256 bytes
SHORT_BINUNICODE = b'\x8c' # push short string; UTF-8 length < 256 bytes
BINUNICODE8 = b'\x8d' # push very long string
BINBYTES8 = b'\x8e' # push very long bytes string
EMPTY_SET = b'\x8f' # push empty set on the stack
ADDITEMS = b'\x90' # modify set by adding topmost stack items
FROZENSET = b'\x91' # build frozenset from topmost stack items
NEWOBJ_EX = b'\x92' # like NEWOBJ but work with keyword only arguments
STACK_GLOBAL = b'\x93' # same as GLOBAL but using names on the stacks
MEMOIZE = b'\x94' # store top of the stack in memo
FRAME = b'\x95' # indicate the beginning of a new frame
BYTEARRAY8 = b'\x96' # push bytearray
NEXT_BUFFER = b'\x97' # push next out-of-band buffer
READONLY_BUFFER = b'\x98' # make top of stack readonly
__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$", x)])
_FRAME_SIZE_TARGET = 64 * 1024
def __init__(self, file_write):
self.file_write = file_write
self.current_frame = None
self.current_frame = io.BytesIO()
if self.current_frame and self.current_frame.tell() > 0:
self.commit_frame(force=True)
self.current_frame = None
def commit_frame(self, force=False):
if f.tell() >= self._FRAME_SIZE_TARGET or force:
if len(data) >= self._FRAME_SIZE_MIN:
# Issue a single call to the write method of the underlying
# file object for the frame opcode with the size of the
# frame. The concatenation is expected to be less expensive
# than issuing an additional call to write.
write(FRAME + pack("<Q", len(data)))
# Issue a separate call to write to append the frame
# contents without concatenation to the above to avoid a
# Start the new frame with a new io.BytesIO instance so that
# the file object can have delayed access to the previous frame
# contents via an unreleased memoryview of the previous
self.current_frame = io.BytesIO()
return self.current_frame.write(data)
return self.file_write(data)
def write_large_bytes(self, header, payload):
# Terminate the current frame and flush it to the file.
self.commit_frame(force=True)
# Perform direct write of the header and payload of the large binary
# object. Be careful not to concatenate the header and the payload
# prior to calling 'write' as we do not want to allocate a large
# temporary bytes object.
# We intentionally do not insert a protocol 4 frame opcode to make
# it possible to optimize file.read calls in the loader.
def __init__(self, file_read, file_readline, file_tell=None):
self.file_read = file_read
self.file_readline = file_readline
self.current_frame = None
n = self.current_frame.readinto(buf)
if n == 0 and len(buf) != 0:
self.current_frame = None
buf[:] = self.file_read(n)
"pickle exhausted before end of frame")
buf[:] = self.file_read(n)
data = self.current_frame.read(n)
self.current_frame = None
"pickle exhausted before end of frame")
data = self.current_frame.readline()
self.current_frame = None
return self.file_readline()
"pickle exhausted before end of frame")
return self.file_readline()
def load_frame(self, frame_size):
if self.current_frame and self.current_frame.read() != b'':
"beginning of a new frame before end of current frame")
self.current_frame = io.BytesIO(self.file_read(frame_size))
# Tools used for pickling.
def _getattribute(obj, name):
for subpath in name.split('.'):
if subpath == '<locals>':
raise AttributeError("Can't get local attribute {!r} on {!r}"
obj = getattr(obj, subpath)
raise AttributeError("Can't get attribute {!r} on {!r}"
.format(name, obj)) from None
def whichmodule(obj, name):
"""Find the module an object belong to."""
module_name = getattr(obj, '__module__', None)
if module_name is not None:
# Protect the iteration by using a list copy of sys.modules against dynamic
# modules that trigger imports of other modules upon calls to getattr.
for module_name, module in sys.modules.copy().items():
if (module_name == '__main__'
or module_name == '__mp_main__' # bpo-42406
if _getattribute(module, name)[0] is obj:
r"""Encode a long to a two's complement little-endian binary string.
Note that 0 is a special case, returning an empty string, to save a
byte in the LONG1 pickling context.
nbytes = (x.bit_length() >> 3) + 1
result = x.to_bytes(nbytes, byteorder='little', signed=True)
if result[-1] == 0xff and (result[-2] & 0x80) != 0:
r"""Decode a long from a two's complement little-endian binary string.
>>> decode_long(b"\xff\x00")
>>> decode_long(b"\xff\x7f")
>>> decode_long(b"\x00\xff")
>>> decode_long(b"\x00\x80")
return int.from_bytes(data, byteorder='little', signed=True)
def __init__(self, file, protocol=None, *, fix_imports=True,
"""This takes a binary file for writing a pickle data stream.
The optional *protocol* argument tells the pickler to use the
given protocol; supported protocols are 0, 1, 2, 3, 4 and 5.
The default protocol is 4. It was introduced in Python 3.4, and
is incompatible with previous versions.
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
The *file* argument must have a write() method that accepts a
single bytes argument. It can thus be a file object opened for
binary writing, an io.BytesIO instance, or any other custom
object that meets this interface.
If *fix_imports* is True and *protocol* is less than 3, pickle
will try to map the new Python 3 names to the old module names
used in Python 2, so that the pickle data stream is readable
If *buffer_callback* is None (the default), buffer views are
serialized into *file* as part of the pickle stream.
If *buffer_callback* is not None, then it can be called any number
of times with a buffer view. If the callback returns a false value
(such as None), the given buffer is out-of-band; otherwise the
buffer is serialized in-band, i.e. inside the pickle stream.
It is an error if *buffer_callback* is not None and *protocol*
is None or smaller than 5.
protocol = DEFAULT_PROTOCOL
protocol = HIGHEST_PROTOCOL
elif not 0 <= protocol <= HIGHEST_PROTOCOL:
raise ValueError("pickle protocol must be <= %d" % HIGHEST_PROTOCOL)
if buffer_callback is not None and protocol < 5:
raise ValueError("buffer_callback needs protocol >= 5")
self._buffer_callback = buffer_callback
self._file_write = file.write
raise TypeError("file must have a 'write' attribute")
self.framer = _Framer(self._file_write)
self.write = self.framer.write
self._write_large_bytes = self.framer.write_large_bytes
self.proto = int(protocol)
self.fix_imports = fix_imports and protocol < 3
"""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.
"""Write a pickled representation of obj to the open file."""
# Check whether Pickler was initialized correctly. This is
# only needed to mimic the behavior of _pickle.Pickler.dump().
if not hasattr(self, "_file_write"):
raise PicklingError("Pickler.__init__() was not called by "
"%s.__init__()" % (self.__class__.__name__,))
self.write(PROTO + pack("<B", self.proto))
self.framer.start_framing()
self.framer.end_framing()
"""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
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