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![Guido van Rossum](/assets/img/avatar_default.png)
for bytes. This is the default protocol. It intentionally cannot be unpickled by Python 2.x. - When a pickle written by Python 2.x contains an (8-bit) str instance, this is now decoded to a (Unicode) str instance. The encoding used to do this defaults to ASCII, but can be overridden via two new keyword arguments to the Unpickler class. Previously this would create bytes instances, which is usually wrong: str instances are often used to pickle attribute names etc., and text is more common than binary data anyway.
1351 lines
43 KiB
Python
1351 lines
43 KiB
Python
"""Create portable serialized representations of Python objects.
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See module copy_reg for a mechanism for registering custom picklers.
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See module pickletools source for extensive comments.
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Classes:
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Pickler
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Unpickler
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Functions:
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dump(object, file)
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dumps(object) -> string
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load(file) -> object
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loads(string) -> object
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Misc variables:
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__version__
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format_version
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compatible_formats
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"""
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__version__ = "$Revision$" # Code version
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from types import FunctionType, BuiltinFunctionType
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from copy_reg import dispatch_table
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from copy_reg import _extension_registry, _inverted_registry, _extension_cache
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import marshal
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import sys
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import struct
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import re
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import io
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import codecs
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__all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler",
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"Unpickler", "dump", "dumps", "load", "loads"]
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# Shortcut for use in isinstance testing
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bytes_types = (bytes, bytearray, memoryview)
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# These are purely informational; no code uses these.
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format_version = "3.0" # File format version we write
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compatible_formats = ["1.0", # Original protocol 0
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"1.1", # Protocol 0 with INST added
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"1.2", # Original protocol 1
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"1.3", # Protocol 1 with BINFLOAT added
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"2.0", # Protocol 2
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"3.0", # Protocol 3
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] # Old format versions we can read
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# This is the highest protocol number we know how to read.
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HIGHEST_PROTOCOL = 3
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# The protocol we write by default. May be less than HIGHEST_PROTOCOL.
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# We intentionally write a protocol that Python 2.x cannot read;
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# there are too many issues with that.
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DEFAULT_PROTOCOL = 3
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# Why use struct.pack() for pickling but marshal.loads() for
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# unpickling? struct.pack() is 40% faster than marshal.dumps(), but
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# marshal.loads() is twice as fast as struct.unpack()!
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mloads = marshal.loads
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class PickleError(Exception):
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"""A common base class for the other pickling exceptions."""
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pass
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class PicklingError(PickleError):
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"""This exception is raised when an unpicklable object is passed to the
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dump() method.
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"""
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pass
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class UnpicklingError(PickleError):
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"""This exception is raised when there is a problem unpickling an object,
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such as a security violation.
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Note that other exceptions may also be raised during unpickling, including
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(but not necessarily limited to) AttributeError, EOFError, ImportError,
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and IndexError.
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"""
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pass
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# An instance of _Stop is raised by Unpickler.load_stop() in response to
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# the STOP opcode, passing the object that is the result of unpickling.
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class _Stop(Exception):
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def __init__(self, value):
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self.value = value
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# Jython has PyStringMap; it's a dict subclass with string keys
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try:
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from org.python.core import PyStringMap
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except ImportError:
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PyStringMap = None
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# Pickle opcodes. See pickletools.py for extensive docs. The listing
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# here is in kind-of alphabetical order of 1-character pickle code.
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# pickletools groups them by purpose.
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MARK = b'(' # push special markobject on stack
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STOP = b'.' # every pickle ends with STOP
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POP = b'0' # discard topmost stack item
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POP_MARK = b'1' # discard stack top through topmost markobject
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DUP = b'2' # duplicate top stack item
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FLOAT = b'F' # push float object; decimal string argument
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INT = b'I' # push integer or bool; decimal string argument
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BININT = b'J' # push four-byte signed int
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BININT1 = b'K' # push 1-byte unsigned int
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LONG = b'L' # push long; decimal string argument
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BININT2 = b'M' # push 2-byte unsigned int
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NONE = b'N' # push None
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PERSID = b'P' # push persistent object; id is taken from string arg
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BINPERSID = b'Q' # " " " ; " " " " stack
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REDUCE = b'R' # apply callable to argtuple, both on stack
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STRING = b'S' # push string; NL-terminated string argument
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BINSTRING = b'T' # push string; counted binary string argument
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SHORT_BINSTRING= b'U' # " " ; " " " " < 256 bytes
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UNICODE = b'V' # push Unicode string; raw-unicode-escaped'd argument
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BINUNICODE = b'X' # " " " ; counted UTF-8 string argument
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APPEND = b'a' # append stack top to list below it
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BUILD = b'b' # call __setstate__ or __dict__.update()
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GLOBAL = b'c' # push self.find_class(modname, name); 2 string args
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DICT = b'd' # build a dict from stack items
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EMPTY_DICT = b'}' # push empty dict
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APPENDS = b'e' # extend list on stack by topmost stack slice
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GET = b'g' # push item from memo on stack; index is string arg
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BINGET = b'h' # " " " " " " ; " " 1-byte arg
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INST = b'i' # build & push class instance
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LONG_BINGET = b'j' # push item from memo on stack; index is 4-byte arg
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LIST = b'l' # build list from topmost stack items
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EMPTY_LIST = b']' # push empty list
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OBJ = b'o' # build & push class instance
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PUT = b'p' # store stack top in memo; index is string arg
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BINPUT = b'q' # " " " " " ; " " 1-byte arg
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LONG_BINPUT = b'r' # " " " " " ; " " 4-byte arg
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SETITEM = b's' # add key+value pair to dict
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TUPLE = b't' # build tuple from topmost stack items
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EMPTY_TUPLE = b')' # push empty tuple
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SETITEMS = b'u' # modify dict by adding topmost key+value pairs
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BINFLOAT = b'G' # push float; arg is 8-byte float encoding
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TRUE = b'I01\n' # not an opcode; see INT docs in pickletools.py
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FALSE = b'I00\n' # not an opcode; see INT docs in pickletools.py
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# Protocol 2
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PROTO = b'\x80' # identify pickle protocol
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NEWOBJ = b'\x81' # build object by applying cls.__new__ to argtuple
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EXT1 = b'\x82' # push object from extension registry; 1-byte index
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EXT2 = b'\x83' # ditto, but 2-byte index
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EXT4 = b'\x84' # ditto, but 4-byte index
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TUPLE1 = b'\x85' # build 1-tuple from stack top
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TUPLE2 = b'\x86' # build 2-tuple from two topmost stack items
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TUPLE3 = b'\x87' # build 3-tuple from three topmost stack items
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NEWTRUE = b'\x88' # push True
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NEWFALSE = b'\x89' # push False
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LONG1 = b'\x8a' # push long from < 256 bytes
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LONG4 = b'\x8b' # push really big long
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_tuplesize2code = [EMPTY_TUPLE, TUPLE1, TUPLE2, TUPLE3]
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# Protocol 3 (Python 3.x)
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BINBYTES = b'B' # push bytes; counted binary string argument
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SHORT_BINBYTES = b'C' # " " ; " " " " < 256 bytes
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__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$",x)])
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# Pickling machinery
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class Pickler:
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def __init__(self, file, protocol=None):
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"""This takes a binary file for writing a pickle data stream.
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All protocols now read and write bytes.
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The optional protocol argument tells the pickler to use the
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given protocol; supported protocols are 0, 1, 2. The default
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protocol is 2; it's been supported for many years now.
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Protocol 1 is more efficient than protocol 0; protocol 2 is
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more efficient than protocol 1.
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Specifying a negative protocol version selects the highest
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protocol version supported. The higher the protocol used, the
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more recent the version of Python needed to read the pickle
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produced.
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The file parameter must have a write() method that accepts a single
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string argument. It can thus be an open file object, a StringIO
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object, or any other custom object that meets this interface.
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"""
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if protocol is None:
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protocol = DEFAULT_PROTOCOL
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if protocol < 0:
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protocol = HIGHEST_PROTOCOL
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elif not 0 <= protocol <= HIGHEST_PROTOCOL:
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raise ValueError("pickle protocol must be <= %d" % HIGHEST_PROTOCOL)
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self.write = file.write
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self.memo = {}
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self.proto = int(protocol)
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self.bin = protocol >= 1
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self.fast = 0
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def clear_memo(self):
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"""Clears the pickler's "memo".
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The memo is the data structure that remembers which objects the
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pickler has already seen, so that shared or recursive objects are
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pickled by reference and not by value. This method is useful when
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re-using picklers.
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"""
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self.memo.clear()
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def dump(self, obj):
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"""Write a pickled representation of obj to the open file."""
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if self.proto >= 2:
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self.write(PROTO + bytes([self.proto]))
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self.save(obj)
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self.write(STOP)
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def memoize(self, obj):
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"""Store an object in the memo."""
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# The Pickler memo is a dictionary mapping object ids to 2-tuples
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# that contain the Unpickler memo key and the object being memoized.
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# The memo key is written to the pickle and will become
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# the key in the Unpickler's memo. The object is stored in the
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# Pickler memo so that transient objects are kept alive during
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# pickling.
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# The use of the Unpickler memo length as the memo key is just a
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# convention. The only requirement is that the memo values be unique.
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# But there appears no advantage to any other scheme, and this
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# scheme allows the Unpickler memo to be implemented as a plain (but
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# growable) array, indexed by memo key.
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if self.fast:
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return
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assert id(obj) not in self.memo
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memo_len = len(self.memo)
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self.write(self.put(memo_len))
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self.memo[id(obj)] = memo_len, obj
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# Return a PUT (BINPUT, LONG_BINPUT) opcode string, with argument i.
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def put(self, i, pack=struct.pack):
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if self.bin:
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if i < 256:
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return BINPUT + bytes([i])
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else:
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return LONG_BINPUT + pack("<i", i)
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return PUT + repr(i).encode("ascii") + b'\n'
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# Return a GET (BINGET, LONG_BINGET) opcode string, with argument i.
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def get(self, i, pack=struct.pack):
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if self.bin:
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if i < 256:
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return BINGET + bytes([i])
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else:
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return LONG_BINGET + pack("<i", i)
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return GET + repr(i).encode("ascii") + b'\n'
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def save(self, obj):
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# Check for persistent id (defined by a subclass)
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pid = self.persistent_id(obj)
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if pid:
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self.save_pers(pid)
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return
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# Check the memo
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x = self.memo.get(id(obj))
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if x:
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self.write(self.get(x[0]))
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return
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# Check the type dispatch table
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t = type(obj)
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f = self.dispatch.get(t)
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if f:
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f(self, obj) # Call unbound method with explicit self
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return
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# Check for a class with a custom metaclass; treat as regular class
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try:
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issc = issubclass(t, type)
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except TypeError: # t is not a class (old Boost; see SF #502085)
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issc = 0
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if issc:
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self.save_global(obj)
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return
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# Check copy_reg.dispatch_table
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reduce = dispatch_table.get(t)
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if reduce:
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rv = reduce(obj)
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else:
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# Check for a __reduce_ex__ method, fall back to __reduce__
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reduce = getattr(obj, "__reduce_ex__", None)
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if reduce:
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rv = reduce(self.proto)
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else:
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reduce = getattr(obj, "__reduce__", None)
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if reduce:
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rv = reduce()
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else:
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raise PicklingError("Can't pickle %r object: %r" %
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(t.__name__, obj))
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# Check for string returned by reduce(), meaning "save as global"
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if isinstance(rv, str):
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self.save_global(obj, rv)
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return
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# Assert that reduce() returned a tuple
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if not isinstance(rv, tuple):
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raise PicklingError("%s must return string or tuple" % reduce)
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# Assert that it returned an appropriately sized tuple
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l = len(rv)
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if not (2 <= l <= 5):
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raise PicklingError("Tuple returned by %s must have "
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"two to five elements" % reduce)
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# Save the reduce() output and finally memoize the object
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self.save_reduce(obj=obj, *rv)
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def persistent_id(self, obj):
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# This exists so a subclass can override it
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return None
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def save_pers(self, pid):
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# Save a persistent id reference
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if self.bin:
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self.save(pid)
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self.write(BINPERSID)
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else:
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self.write(PERSID + str(pid).encode("ascii") + b'\n')
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def save_reduce(self, func, args, state=None,
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listitems=None, dictitems=None, obj=None):
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# This API is called by some subclasses
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# Assert that args is a tuple or None
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if not isinstance(args, tuple):
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raise PicklingError("args from reduce() should be a tuple")
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# Assert that func is callable
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if not hasattr(func, '__call__'):
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raise PicklingError("func from reduce should be callable")
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save = self.save
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write = self.write
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# Protocol 2 special case: if func's name is __newobj__, use NEWOBJ
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if self.proto >= 2 and getattr(func, "__name__", "") == "__newobj__":
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# A __reduce__ implementation can direct protocol 2 to
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# use the more efficient NEWOBJ opcode, while still
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# allowing protocol 0 and 1 to work normally. For this to
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# work, the function returned by __reduce__ should be
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# called __newobj__, and its first argument should be a
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# new-style class. The implementation for __newobj__
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# should be as follows, although pickle has no way to
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# verify this:
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#
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# def __newobj__(cls, *args):
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# return cls.__new__(cls, *args)
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#
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# Protocols 0 and 1 will pickle a reference to __newobj__,
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# while protocol 2 (and above) will pickle a reference to
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# cls, the remaining args tuple, and the NEWOBJ code,
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# which calls cls.__new__(cls, *args) at unpickling time
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# (see load_newobj below). If __reduce__ returns a
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# three-tuple, the state from the third tuple item will be
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# pickled regardless of the protocol, calling __setstate__
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# at unpickling time (see load_build below).
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#
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# Note that no standard __newobj__ implementation exists;
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# you have to provide your own. This is to enforce
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# compatibility with Python 2.2 (pickles written using
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# protocol 0 or 1 in Python 2.3 should be unpicklable by
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# Python 2.2).
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cls = args[0]
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if not hasattr(cls, "__new__"):
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raise PicklingError(
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"args[0] from __newobj__ args has no __new__")
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if obj is not None and cls is not obj.__class__:
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raise PicklingError(
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"args[0] from __newobj__ args has the wrong class")
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args = args[1:]
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save(cls)
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save(args)
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write(NEWOBJ)
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else:
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save(func)
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save(args)
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write(REDUCE)
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if obj is not None:
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self.memoize(obj)
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# More new special cases (that work with older protocols as
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# well): when __reduce__ returns a tuple with 4 or 5 items,
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# the 4th and 5th item should be iterators that provide list
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# items and dict items (as (key, value) tuples), or None.
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if listitems is not None:
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self._batch_appends(listitems)
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if dictitems is not None:
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self._batch_setitems(dictitems)
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if state is not None:
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save(state)
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write(BUILD)
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# Methods below this point are dispatched through the dispatch table
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dispatch = {}
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def save_none(self, obj):
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self.write(NONE)
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dispatch[type(None)] = save_none
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def save_bool(self, obj):
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if self.proto >= 2:
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self.write(obj and NEWTRUE or NEWFALSE)
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else:
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self.write(obj and TRUE or FALSE)
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dispatch[bool] = save_bool
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def save_int(self, obj, pack=struct.pack):
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if self.bin:
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# If the int is small enough to fit in a signed 4-byte 2's-comp
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# format, we can store it more efficiently than the general
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# case.
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# First one- and two-byte unsigned ints:
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if obj >= 0:
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if obj <= 0xff:
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self.write(BININT1 + bytes([obj]))
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return
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if obj <= 0xffff:
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self.write(BININT2 + bytes([obj&0xff, obj>>8]))
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return
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# Next check for 4-byte signed ints:
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high_bits = obj >> 31 # note that Python shift sign-extends
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if high_bits == 0 or high_bits == -1:
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# All high bits are copies of bit 2**31, so the value
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# fits in a 4-byte signed int.
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self.write(BININT + pack("<i", obj))
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return
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# Text pickle, or int too big to fit in signed 4-byte format.
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self.write(INT + repr(obj).encode("ascii") + b'\n')
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# XXX save_int is merged into save_long
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# dispatch[int] = save_int
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def save_long(self, obj, pack=struct.pack):
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if self.bin:
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# If the int is small enough to fit in a signed 4-byte 2's-comp
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# format, we can store it more efficiently than the general
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# case.
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# First one- and two-byte unsigned ints:
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if obj >= 0:
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if obj <= 0xff:
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self.write(BININT1 + bytes([obj]))
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return
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if obj <= 0xffff:
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self.write(BININT2 + bytes([obj&0xff, obj>>8]))
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return
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# Next check for 4-byte signed ints:
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high_bits = obj >> 31 # note that Python shift sign-extends
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if high_bits == 0 or high_bits == -1:
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# All high bits are copies of bit 2**31, so the value
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# fits in a 4-byte signed int.
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self.write(BININT + pack("<i", obj))
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return
|
|
if self.proto >= 2:
|
|
encoded = encode_long(obj)
|
|
n = len(encoded)
|
|
if n < 256:
|
|
self.write(LONG1 + bytes([n]) + encoded)
|
|
else:
|
|
self.write(LONG4 + pack("<i", n) + encoded)
|
|
return
|
|
self.write(LONG + repr(obj).encode("ascii") + b'\n')
|
|
dispatch[int] = 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).encode("ascii") + b'\n')
|
|
dispatch[float] = save_float
|
|
|
|
def save_bytes(self, obj, pack=struct.pack):
|
|
if self.proto < 3:
|
|
self.save_reduce(bytes, (list(obj),))
|
|
return
|
|
n = len(obj)
|
|
if n < 256:
|
|
self.write(SHORT_BINBYTES + bytes([n]) + bytes(obj))
|
|
else:
|
|
self.write(BINBYTES + pack("<i", n) + bytes(obj))
|
|
self.memoize(obj)
|
|
dispatch[bytes] = save_bytes
|
|
|
|
def save_str(self, obj, pack=struct.pack):
|
|
if self.bin:
|
|
encoded = obj.encode('utf-8')
|
|
n = len(encoded)
|
|
self.write(BINUNICODE + pack("<i", n) + encoded)
|
|
else:
|
|
obj = obj.replace("\\", "\\u005c")
|
|
obj = obj.replace("\n", "\\u000a")
|
|
self.write(UNICODE + bytes(obj.encode('raw-unicode-escape')) +
|
|
b'\n')
|
|
self.memoize(obj)
|
|
dispatch[str] = save_str
|
|
|
|
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[tuple] = 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[list] = save_list
|
|
|
|
_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 = range(self._BATCHSIZE)
|
|
while items is not None:
|
|
tmp = []
|
|
for i in r:
|
|
try:
|
|
x = next(items)
|
|
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(iter(obj.items()))
|
|
|
|
dispatch[dict] = save_dict
|
|
if PyStringMap is not 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 = range(self._BATCHSIZE)
|
|
while items is not None:
|
|
tmp = []
|
|
for i in r:
|
|
try:
|
|
tmp.append(next(items))
|
|
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_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 + bytes([code]))
|
|
elif code <= 0xffff:
|
|
write(EXT2 + bytes([code&0xff, code>>8]))
|
|
else:
|
|
write(EXT4 + pack("<i", code))
|
|
return
|
|
|
|
write(GLOBAL + bytes(module, "utf-8") + b'\n' +
|
|
bytes(name, "utf-8") + b'\n')
|
|
self.memoize(obj)
|
|
|
|
dispatch[FunctionType] = save_global
|
|
dispatch[BuiltinFunctionType] = save_global
|
|
dispatch[type] = 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 list(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, *, encoding="ASCII", errors="strict"):
|
|
"""This takes a binary file 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 bytes.
|
|
Thus file-like object can be a binary file object opened for
|
|
reading, a BytesIO object, or any other custom object that
|
|
meets this interface.
|
|
|
|
Optional keyword arguments are encoding and errors, which are
|
|
used to decode 8-bit string instances pickled by Python 2.x.
|
|
These default to 'ASCII' and 'strict', respectively.
|
|
"""
|
|
self.readline = file.readline
|
|
self.read = file.read
|
|
self.memo = {}
|
|
self.encoding = encoding
|
|
self.errors = errors
|
|
|
|
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)
|
|
if not key:
|
|
raise EOFError
|
|
assert isinstance(key, bytes_types)
|
|
dispatch[key[0]](self)
|
|
except _Stop as 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_proto(self):
|
|
proto = ord(self.read(1))
|
|
if not 0 <= proto <= HIGHEST_PROTOCOL:
|
|
raise ValueError("unsupported pickle protocol: %d" % proto)
|
|
dispatch[PROTO[0]] = load_proto
|
|
|
|
def load_persid(self):
|
|
pid = self.readline()[:-1]
|
|
self.append(self.persistent_load(pid))
|
|
dispatch[PERSID[0]] = load_persid
|
|
|
|
def load_binpersid(self):
|
|
pid = self.stack.pop()
|
|
self.append(self.persistent_load(pid))
|
|
dispatch[BINPERSID[0]] = load_binpersid
|
|
|
|
def load_none(self):
|
|
self.append(None)
|
|
dispatch[NONE[0]] = load_none
|
|
|
|
def load_false(self):
|
|
self.append(False)
|
|
dispatch[NEWFALSE[0]] = load_false
|
|
|
|
def load_true(self):
|
|
self.append(True)
|
|
dispatch[NEWTRUE[0]] = 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 = int(data)
|
|
self.append(val)
|
|
dispatch[INT[0]] = load_int
|
|
|
|
def load_binint(self):
|
|
self.append(mloads(b'i' + self.read(4)))
|
|
dispatch[BININT[0]] = load_binint
|
|
|
|
def load_binint1(self):
|
|
self.append(ord(self.read(1)))
|
|
dispatch[BININT1[0]] = load_binint1
|
|
|
|
def load_binint2(self):
|
|
self.append(mloads(b'i' + self.read(2) + b'\000\000'))
|
|
dispatch[BININT2[0]] = load_binint2
|
|
|
|
def load_long(self):
|
|
val = self.readline()[:-1].decode("ascii")
|
|
self.append(int(val, 0))
|
|
dispatch[LONG[0]] = load_long
|
|
|
|
def load_long1(self):
|
|
n = ord(self.read(1))
|
|
data = self.read(n)
|
|
self.append(decode_long(data))
|
|
dispatch[LONG1[0]] = load_long1
|
|
|
|
def load_long4(self):
|
|
n = mloads(b'i' + self.read(4))
|
|
data = self.read(n)
|
|
self.append(decode_long(data))
|
|
dispatch[LONG4[0]] = load_long4
|
|
|
|
def load_float(self):
|
|
self.append(float(self.readline()[:-1]))
|
|
dispatch[FLOAT[0]] = load_float
|
|
|
|
def load_binfloat(self, unpack=struct.unpack):
|
|
self.append(unpack('>d', self.read(8))[0])
|
|
dispatch[BINFLOAT[0]] = load_binfloat
|
|
|
|
def load_string(self):
|
|
orig = self.readline()
|
|
rep = orig[:-1]
|
|
for q in (b'"', b"'"): # 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: %r" % orig)
|
|
self.append(codecs.escape_decode(rep)[0])
|
|
dispatch[STRING[0]] = load_string
|
|
|
|
def load_binstring(self):
|
|
len = mloads(b'i' + self.read(4))
|
|
data = self.read(len)
|
|
value = str(data, self.encoding, self.errors)
|
|
self.append(value)
|
|
dispatch[BINSTRING[0]] = load_binstring
|
|
|
|
def load_binbytes(self):
|
|
len = mloads(b'i' + self.read(4))
|
|
self.append(self.read(len))
|
|
dispatch[BINBYTES[0]] = load_binbytes
|
|
|
|
def load_unicode(self):
|
|
self.append(str(self.readline()[:-1], 'raw-unicode-escape'))
|
|
dispatch[UNICODE[0]] = load_unicode
|
|
|
|
def load_binunicode(self):
|
|
len = mloads(b'i' + self.read(4))
|
|
self.append(str(self.read(len), 'utf-8'))
|
|
dispatch[BINUNICODE[0]] = load_binunicode
|
|
|
|
def load_short_binstring(self):
|
|
len = ord(self.read(1))
|
|
data = bytes(self.read(len))
|
|
value = str(data, self.encoding, self.errors)
|
|
self.append(value)
|
|
dispatch[SHORT_BINSTRING[0]] = load_short_binstring
|
|
|
|
def load_short_binbytes(self):
|
|
len = ord(self.read(1))
|
|
self.append(bytes(self.read(len)))
|
|
dispatch[SHORT_BINBYTES[0]] = load_short_binbytes
|
|
|
|
def load_tuple(self):
|
|
k = self.marker()
|
|
self.stack[k:] = [tuple(self.stack[k+1:])]
|
|
dispatch[TUPLE[0]] = load_tuple
|
|
|
|
def load_empty_tuple(self):
|
|
self.stack.append(())
|
|
dispatch[EMPTY_TUPLE[0]] = load_empty_tuple
|
|
|
|
def load_tuple1(self):
|
|
self.stack[-1] = (self.stack[-1],)
|
|
dispatch[TUPLE1[0]] = load_tuple1
|
|
|
|
def load_tuple2(self):
|
|
self.stack[-2:] = [(self.stack[-2], self.stack[-1])]
|
|
dispatch[TUPLE2[0]] = load_tuple2
|
|
|
|
def load_tuple3(self):
|
|
self.stack[-3:] = [(self.stack[-3], self.stack[-2], self.stack[-1])]
|
|
dispatch[TUPLE3[0]] = load_tuple3
|
|
|
|
def load_empty_list(self):
|
|
self.stack.append([])
|
|
dispatch[EMPTY_LIST[0]] = load_empty_list
|
|
|
|
def load_empty_dictionary(self):
|
|
self.stack.append({})
|
|
dispatch[EMPTY_DICT[0]] = load_empty_dictionary
|
|
|
|
def load_list(self):
|
|
k = self.marker()
|
|
self.stack[k:] = [self.stack[k+1:]]
|
|
dispatch[LIST[0]] = 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[0]] = 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
|
|
isinstance(klass, type) and
|
|
not hasattr(klass, "__getinitargs__")):
|
|
value = _EmptyClass()
|
|
value.__class__ = klass
|
|
instantiated = 1
|
|
if not instantiated:
|
|
try:
|
|
value = klass(*args)
|
|
except TypeError as 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[0]] = 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[0]] = 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[0]] = 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[0]] = load_global
|
|
|
|
def load_ext1(self):
|
|
code = ord(self.read(1))
|
|
self.get_extension(code)
|
|
dispatch[EXT1[0]] = load_ext1
|
|
|
|
def load_ext2(self):
|
|
code = mloads(b'i' + self.read(2) + b'\000\000')
|
|
self.get_extension(code)
|
|
dispatch[EXT2[0]] = load_ext2
|
|
|
|
def load_ext4(self):
|
|
code = mloads(b'i' + self.read(4))
|
|
self.get_extension(code)
|
|
dispatch[EXT4[0]] = 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
|
|
if isinstance(module, bytes_types):
|
|
module = module.decode("utf-8")
|
|
if isinstance(name, bytes_types):
|
|
name = name.decode("utf-8")
|
|
__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]
|
|
try:
|
|
value = func(*args)
|
|
except:
|
|
print(sys.exc_info())
|
|
print(func, args)
|
|
raise
|
|
stack[-1] = value
|
|
dispatch[REDUCE[0]] = load_reduce
|
|
|
|
def load_pop(self):
|
|
del self.stack[-1]
|
|
dispatch[POP[0]] = load_pop
|
|
|
|
def load_pop_mark(self):
|
|
k = self.marker()
|
|
del self.stack[k:]
|
|
dispatch[POP_MARK[0]] = load_pop_mark
|
|
|
|
def load_dup(self):
|
|
self.append(self.stack[-1])
|
|
dispatch[DUP[0]] = load_dup
|
|
|
|
def load_get(self):
|
|
self.append(self.memo[self.readline()[:-1].decode("ascii")])
|
|
dispatch[GET[0]] = load_get
|
|
|
|
def load_binget(self):
|
|
i = ord(self.read(1))
|
|
self.append(self.memo[repr(i)])
|
|
dispatch[BINGET[0]] = load_binget
|
|
|
|
def load_long_binget(self):
|
|
i = mloads(b'i' + self.read(4))
|
|
self.append(self.memo[repr(i)])
|
|
dispatch[LONG_BINGET[0]] = load_long_binget
|
|
|
|
def load_put(self):
|
|
self.memo[self.readline()[:-1].decode("ascii")] = self.stack[-1]
|
|
dispatch[PUT[0]] = load_put
|
|
|
|
def load_binput(self):
|
|
i = ord(self.read(1))
|
|
self.memo[repr(i)] = self.stack[-1]
|
|
dispatch[BINPUT[0]] = load_binput
|
|
|
|
def load_long_binput(self):
|
|
i = mloads(b'i' + self.read(4))
|
|
self.memo[repr(i)] = self.stack[-1]
|
|
dispatch[LONG_BINPUT[0]] = load_long_binput
|
|
|
|
def load_append(self):
|
|
stack = self.stack
|
|
value = stack.pop()
|
|
list = stack[-1]
|
|
list.append(value)
|
|
dispatch[APPEND[0]] = 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[0]] = load_appends
|
|
|
|
def load_setitem(self):
|
|
stack = self.stack
|
|
value = stack.pop()
|
|
key = stack.pop()
|
|
dict = stack[-1]
|
|
dict[key] = value
|
|
dispatch[SETITEM[0]] = 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[0]] = 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:
|
|
inst.__dict__.update(state)
|
|
if slotstate:
|
|
for k, v in slotstate.items():
|
|
setattr(inst, k, v)
|
|
dispatch[BUILD[0]] = load_build
|
|
|
|
def load_mark(self):
|
|
self.append(self.mark)
|
|
dispatch[MARK[0]] = load_mark
|
|
|
|
def load_stop(self):
|
|
value = self.stack.pop()
|
|
raise _Stop(value)
|
|
dispatch[STOP[0]] = 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 0 is a special case, returning an empty string, to save a
|
|
byte in the LONG1 pickling context.
|
|
|
|
>>> encode_long(0)
|
|
b''
|
|
>>> encode_long(255)
|
|
b'\xff\x00'
|
|
>>> encode_long(32767)
|
|
b'\xff\x7f'
|
|
>>> encode_long(-256)
|
|
b'\x00\xff'
|
|
>>> encode_long(-32768)
|
|
b'\x00\x80'
|
|
>>> encode_long(-128)
|
|
b'\x80'
|
|
>>> encode_long(127)
|
|
b'\x7f'
|
|
>>>
|
|
"""
|
|
|
|
if x == 0:
|
|
return b''
|
|
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 += 1 << 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 bytes(binary[::-1])
|
|
|
|
def decode_long(data):
|
|
r"""Decode a long from a two's complement little-endian binary string.
|
|
|
|
>>> decode_long(b'')
|
|
0
|
|
>>> decode_long(b"\xff\x00")
|
|
255
|
|
>>> decode_long(b"\xff\x7f")
|
|
32767
|
|
>>> decode_long(b"\x00\xff")
|
|
-256
|
|
>>> decode_long(b"\x00\x80")
|
|
-32768
|
|
>>> decode_long(b"\x80")
|
|
-128
|
|
>>> decode_long(b"\x7f")
|
|
127
|
|
"""
|
|
|
|
nbytes = len(data)
|
|
if nbytes == 0:
|
|
return 0
|
|
ashex = _binascii.hexlify(data[::-1])
|
|
n = int(ashex, 16) # quadratic time before Python 2.3; linear now
|
|
if data[-1] >= 0x80:
|
|
n -= 1 << (nbytes * 8)
|
|
return n
|
|
|
|
# Shorthands
|
|
|
|
def dump(obj, file, protocol=None):
|
|
Pickler(file, protocol).dump(obj)
|
|
|
|
def dumps(obj, protocol=None):
|
|
f = io.BytesIO()
|
|
Pickler(f, protocol).dump(obj)
|
|
res = f.getvalue()
|
|
assert isinstance(res, bytes_types)
|
|
return res
|
|
|
|
def load(file):
|
|
return Unpickler(file).load()
|
|
|
|
def loads(s):
|
|
if isinstance(s, str):
|
|
raise TypeError("Can't load pickle from unicode string")
|
|
file = io.BytesIO(s)
|
|
return Unpickler(file).load()
|
|
|
|
# Doctest
|
|
|
|
def _test():
|
|
import doctest
|
|
return doctest.testmod()
|
|
|
|
if __name__ == "__main__":
|
|
_test()
|