mirror of
https://github.com/python/cpython.git
synced 2024-12-16 21:34:44 +08:00
d9dfaa9487
or dumping pickles with a 2.x-compatible protocol, in order to make data sharing and migration easier. This behaviour can be disabled using the new `fix_imports` optional argument.
1381 lines
46 KiB
Python
1381 lines
46 KiB
Python
"""Create portable serialized representations of Python objects.
|
|
|
|
See module copyreg 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 FunctionType, BuiltinFunctionType
|
|
from copyreg import dispatch_table
|
|
from copyreg import _extension_registry, _inverted_registry, _extension_cache
|
|
import marshal
|
|
import sys
|
|
import struct
|
|
import re
|
|
import io
|
|
import codecs
|
|
import _compat_pickle
|
|
|
|
__all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler",
|
|
"Unpickler", "dump", "dumps", "load", "loads"]
|
|
|
|
# Shortcut for use in isinstance testing
|
|
bytes_types = (bytes, bytearray)
|
|
|
|
# These are purely informational; no code uses these.
|
|
format_version = "3.0" # 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
|
|
"3.0", # Protocol 3
|
|
] # Old format versions we can read
|
|
|
|
# This is the highest protocol number we know how to read.
|
|
HIGHEST_PROTOCOL = 3
|
|
|
|
# The protocol we write by default. May be less than HIGHEST_PROTOCOL.
|
|
# We intentionally write a protocol that Python 2.x cannot read;
|
|
# there are too many issues with that.
|
|
DEFAULT_PROTOCOL = 3
|
|
|
|
# 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
|
|
|
|
# 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
|
|
NONE = b'N' # push None
|
|
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
|
|
|
|
# Protocol 2
|
|
|
|
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
|
|
|
|
__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$",x)])
|
|
|
|
# Pickling machinery
|
|
|
|
class _Pickler:
|
|
|
|
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. The default
|
|
protocol is 3; a backward-incompatible protocol designed for
|
|
Python 3.0.
|
|
|
|
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 argument must have a write() method that accepts a single
|
|
bytes argument. It can thus be a file object opened for binary
|
|
writing, a 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.x names to the old module names used in Python
|
|
2.x, so that the pickle data stream is readable with Python 2.x.
|
|
"""
|
|
if protocol is None:
|
|
protocol = DEFAULT_PROTOCOL
|
|
if protocol < 0:
|
|
protocol = HIGHEST_PROTOCOL
|
|
elif not 0 <= protocol <= HIGHEST_PROTOCOL:
|
|
raise ValueError("pickle protocol must be <= %d" % HIGHEST_PROTOCOL)
|
|
try:
|
|
self.write = file.write
|
|
except AttributeError:
|
|
raise TypeError("file must have a 'write' attribute")
|
|
self.memo = {}
|
|
self.proto = int(protocol)
|
|
self.bin = protocol >= 1
|
|
self.fast = 0
|
|
self.fix_imports = fix_imports and protocol < 3
|
|
|
|
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."""
|
|
# Check whether Pickler was initialized correctly. This is
|
|
# only needed to mimic the behavior of _pickle.Pickler.dump().
|
|
if not hasattr(self, "write"):
|
|
raise PicklingError("Pickler.__init__() was not called by "
|
|
"%s.__init__()" % (self.__class__.__name__,))
|
|
if self.proto >= 2:
|
|
self.write(PROTO + bytes([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 + bytes([i])
|
|
else:
|
|
return LONG_BINPUT + pack("<i", i)
|
|
|
|
return PUT + repr(i).encode("ascii") + b'\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 + bytes([i])
|
|
else:
|
|
return LONG_BINGET + pack("<i", i)
|
|
|
|
return GET + repr(i).encode("ascii") + b'\n'
|
|
|
|
def save(self, obj, save_persistent_id=True):
|
|
# Check for persistent id (defined by a subclass)
|
|
pid = self.persistent_id(obj)
|
|
if pid is not None and save_persistent_id:
|
|
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, type)
|
|
except TypeError: # t is not a class (old Boost; see SF #502085)
|
|
issc = 0
|
|
if issc:
|
|
self.save_global(obj)
|
|
return
|
|
|
|
# Check copyreg.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 isinstance(rv, str):
|
|
self.save_global(obj, rv)
|
|
return
|
|
|
|
# Assert that reduce() returned a tuple
|
|
if not isinstance(rv, tuple):
|
|
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, save_persistent_id=False)
|
|
self.write(BINPERSID)
|
|
else:
|
|
self.write(PERSID + str(pid).encode("ascii") + b'\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
|
|
if not isinstance(args, tuple):
|
|
raise PicklingError("args from save_reduce() should be a tuple")
|
|
|
|
# Assert that func is callable
|
|
if not hasattr(func, '__call__'):
|
|
raise PicklingError("func from save_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[type(None)] = 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_long(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 + bytes([obj]))
|
|
return
|
|
if obj <= 0xffff:
|
|
self.write(BININT2 + bytes([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
|
|
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'L\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),), obj=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
|
|
|
|
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(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
|
|
|
|
items = iter(items)
|
|
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(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
|
|
|
|
items = iter(items)
|
|
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, level=0)
|
|
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
|
|
# Non-ASCII identifiers are supported only with protocols >= 3.
|
|
if self.proto >= 3:
|
|
write(GLOBAL + bytes(module, "utf-8") + b'\n' +
|
|
bytes(name, "utf-8") + b'\n')
|
|
else:
|
|
if self.fix_imports:
|
|
if (module, name) in _compat_pickle.REVERSE_NAME_MAPPING:
|
|
module, name = _compat_pickle.REVERSE_NAME_MAPPING[(module, name)]
|
|
if module in _compat_pickle.REVERSE_IMPORT_MAPPING:
|
|
module = _compat_pickle.REVERSE_IMPORT_MAPPING[module]
|
|
try:
|
|
write(GLOBAL + bytes(module, "ascii") + b'\n' +
|
|
bytes(name, "ascii") + b'\n')
|
|
except UnicodeEncodeError:
|
|
raise PicklingError(
|
|
"can't pickle global identifier '%s.%s' using "
|
|
"pickle protocol %i" % (module, name, self.proto))
|
|
|
|
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, *, fix_imports=True,
|
|
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 *fix_imports*, *encoding* and *errors*,
|
|
which are used to control compatiblity support for pickle stream
|
|
generated by Python 2.x. If *fix_imports* is True, pickle will try to
|
|
map the old Python 2.x names to the new names used in Python 3.x. The
|
|
*encoding* and *errors* tell pickle how 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
|
|
self.proto = 0
|
|
self.fix_imports = fix_imports
|
|
|
|
def load(self):
|
|
"""Read a pickled object representation from the open file.
|
|
|
|
Return the reconstituted object hierarchy specified in the file.
|
|
"""
|
|
# Check whether Unpickler was initialized correctly. This is
|
|
# only needed to mimic the behavior of _pickle.Unpickler.dump().
|
|
if not hasattr(self, "read"):
|
|
raise UnpicklingError("Unpickler.__init__() was not called by "
|
|
"%s.__init__()" % (self.__class__.__name__,))
|
|
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
|
|
|
|
def persistent_load(self, pid):
|
|
raise UnpicklingError("unsupported persistent id encountered")
|
|
|
|
dispatch = {}
|
|
|
|
def load_proto(self):
|
|
proto = ord(self.read(1))
|
|
if not 0 <= proto <= HIGHEST_PROTOCOL:
|
|
raise ValueError("unsupported pickle protocol: %d" % proto)
|
|
self.proto = proto
|
|
dispatch[PROTO[0]] = load_proto
|
|
|
|
def load_persid(self):
|
|
pid = self.readline()[:-1].decode("ascii")
|
|
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, 0)
|
|
except ValueError:
|
|
val = int(data, 0)
|
|
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")
|
|
if val and val[-1] == 'L':
|
|
val = val[:-1]
|
|
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]
|
|
.decode(self.encoding, self.errors))
|
|
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.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.append([])
|
|
dispatch[EMPTY_LIST[0]] = load_empty_list
|
|
|
|
def load_empty_dictionary(self):
|
|
self.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 = False
|
|
if (not args and
|
|
isinstance(klass, type) and
|
|
not hasattr(klass, "__getinitargs__")):
|
|
value = _EmptyClass()
|
|
value.__class__ = klass
|
|
instantiated = True
|
|
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].decode("ascii")
|
|
name = self.readline()[:-1].decode("ascii")
|
|
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].decode("utf-8")
|
|
name = self.readline()[:-1].decode("utf-8")
|
|
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 self.proto < 3 and self.fix_imports:
|
|
if (module, name) in _compat_pickle.NAME_MAPPING:
|
|
module, name = _compat_pickle.NAME_MAPPING[(module, name)]
|
|
if module in _compat_pickle.IMPORT_MAPPING:
|
|
module = _compat_pickle.IMPORT_MAPPING[module]
|
|
__import__(module, level=0)
|
|
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):
|
|
i = int(self.readline()[:-1])
|
|
self.append(self.memo[i])
|
|
dispatch[GET[0]] = load_get
|
|
|
|
def load_binget(self):
|
|
i = self.read(1)[0]
|
|
self.append(self.memo[i])
|
|
dispatch[BINGET[0]] = load_binget
|
|
|
|
def load_long_binget(self):
|
|
i = mloads(b'i' + self.read(4))
|
|
self.append(self.memo[i])
|
|
dispatch[LONG_BINGET[0]] = load_long_binget
|
|
|
|
def load_put(self):
|
|
i = int(self.readline()[:-1])
|
|
self.memo[i] = self.stack[-1]
|
|
dispatch[PUT[0]] = load_put
|
|
|
|
def load_binput(self):
|
|
i = self.read(1)[0]
|
|
self.memo[i] = self.stack[-1]
|
|
dispatch[BINPUT[0]] = load_binput
|
|
|
|
def load_long_binput(self):
|
|
i = mloads(b'i' + self.read(4))
|
|
self.memo[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 = inst.__dict__
|
|
intern = sys.intern
|
|
for k, v in state.items():
|
|
if type(k) is str:
|
|
inst_dict[intern(k)] = v
|
|
else:
|
|
inst_dict[k] = v
|
|
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
|
|
|
|
# Use the faster _pickle if possible
|
|
try:
|
|
from _pickle import *
|
|
except ImportError:
|
|
Pickler, Unpickler = _Pickler, _Unpickler
|
|
|
|
# Shorthands
|
|
|
|
def dump(obj, file, protocol=None, *, fix_imports=True):
|
|
Pickler(file, protocol, fix_imports=fix_imports).dump(obj)
|
|
|
|
def dumps(obj, protocol=None, *, fix_imports=True):
|
|
f = io.BytesIO()
|
|
Pickler(f, protocol, fix_imports=fix_imports).dump(obj)
|
|
res = f.getvalue()
|
|
assert isinstance(res, bytes_types)
|
|
return res
|
|
|
|
def load(file, *, fix_imports=True, encoding="ASCII", errors="strict"):
|
|
return Unpickler(file, fix_imports=fix_imports,
|
|
encoding=encoding, errors=errors).load()
|
|
|
|
def loads(s, *, fix_imports=True, encoding="ASCII", errors="strict"):
|
|
if isinstance(s, str):
|
|
raise TypeError("Can't load pickle from unicode string")
|
|
file = io.BytesIO(s)
|
|
return Unpickler(file, fix_imports=fix_imports,
|
|
encoding=encoding, errors=errors).load()
|
|
|
|
# Doctest
|
|
def _test():
|
|
import doctest
|
|
return doctest.testmod()
|
|
|
|
if __name__ == "__main__":
|
|
_test()
|