add ydb deps

1 files changed, 1820 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Lib/pickle.py b/contrib/tools/python3/src/Lib/pickle.py
new file mode 100644
index 0000000000..f027e04320
--- /dev/null
+++ b/contrib/tools/python3/src/Lib/pickle.py
@@ -0,0 +1,1820 @@
+"""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(bytes) -> object
+
+Misc variables:
+
+    __version__
+    format_version
+    compatible_formats
+
+"""
+
+from types import FunctionType
+from copyreg import dispatch_table
+from copyreg import _extension_registry, _inverted_registry, _extension_cache
+from itertools import islice
+from functools import partial
+import sys
+from sys import maxsize
+from struct import pack, unpack
+import re
+import io
+import codecs
+import _compat_pickle
+
+__all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler",
+           "Unpickler", "dump", "dumps", "load", "loads"]
+
+try:
+    from _pickle import PickleBuffer
+    __all__.append("PickleBuffer")
+    _HAVE_PICKLE_BUFFER = True
+except ImportError:
+    _HAVE_PICKLE_BUFFER = False
+
+
+# Shortcut for use in isinstance testing
+bytes_types = (bytes, bytearray)
+
+# These are purely informational; no code uses these.
+format_version = "4.0"                  # File format version we write
+compatible_formats = ["1.0",            # Original protocol 0
+                      "1.1",            # Protocol 0 with INST added
+                      "1.2",            # Original protocol 1
+                      "1.3",            # Protocol 1 with BINFLOAT added
+                      "2.0",            # Protocol 2
+                      "3.0",            # Protocol 3
+                      "4.0",            # Protocol 4
+                      "5.0",            # Protocol 5
+                      ]                 # Old format versions we can read
+
+# This is the highest protocol number we know how to read.
+HIGHEST_PROTOCOL = 5
+
+# The protocol we write by default.  May be less than HIGHEST_PROTOCOL.
+# Only bump this if the oldest still supported version of Python already
+# includes it.
+DEFAULT_PROTOCOL = 4
+
+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
+
+# Protocol 4
+
+SHORT_BINUNICODE = b'\x8c'  # push short string; UTF-8 length < 256 bytes
+BINUNICODE8      = b'\x8d'  # push very long string
+BINBYTES8        = b'\x8e'  # push very long bytes string
+EMPTY_SET        = b'\x8f'  # push empty set on the stack
+ADDITEMS         = b'\x90'  # modify set by adding topmost stack items
+FROZENSET        = b'\x91'  # build frozenset from topmost stack items
+NEWOBJ_EX        = b'\x92'  # like NEWOBJ but work with keyword only arguments
+STACK_GLOBAL     = b'\x93'  # same as GLOBAL but using names on the stacks
+MEMOIZE          = b'\x94'  # store top of the stack in memo
+FRAME            = b'\x95'  # indicate the beginning of a new frame
+
+# Protocol 5
+
+BYTEARRAY8       = b'\x96'  # push bytearray
+NEXT_BUFFER      = b'\x97'  # push next out-of-band buffer
+READONLY_BUFFER  = b'\x98'  # make top of stack readonly
+
+__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$", x)])
+
+
+class _Framer:
+
+    _FRAME_SIZE_MIN = 4
+    _FRAME_SIZE_TARGET = 64 * 1024
+
+    def __init__(self, file_write):
+        self.file_write = file_write
+        self.current_frame = None
+
+    def start_framing(self):
+        self.current_frame = io.BytesIO()
+
+    def end_framing(self):
+        if self.current_frame and self.current_frame.tell() > 0:
+            self.commit_frame(force=True)
+            self.current_frame = None
+
+    def commit_frame(self, force=False):
+        if self.current_frame:
+            f = self.current_frame
+            if f.tell() >= self._FRAME_SIZE_TARGET or force:
+                data = f.getbuffer()
+                write = self.file_write
+                if len(data) >= self._FRAME_SIZE_MIN:
+                    # Issue a single call to the write method of the underlying
+                    # file object for the frame opcode with the size of the
+                    # frame. The concatenation is expected to be less expensive
+                    # than issuing an additional call to write.
+                    write(FRAME + pack("<Q", len(data)))
+
+                # Issue a separate call to write to append the frame
+                # contents without concatenation to the above to avoid a
+                # memory copy.
+                write(data)
+
+                # Start the new frame with a new io.BytesIO instance so that
+                # the file object can have delayed access to the previous frame
+                # contents via an unreleased memoryview of the previous
+                # io.BytesIO instance.
+                self.current_frame = io.BytesIO()
+
+    def write(self, data):
+        if self.current_frame:
+            return self.current_frame.write(data)
+        else:
+            return self.file_write(data)
+
+    def write_large_bytes(self, header, payload):
+        write = self.file_write
+        if self.current_frame:
+            # Terminate the current frame and flush it to the file.
+            self.commit_frame(force=True)
+
+        # Perform direct write of the header and payload of the large binary
+        # object. Be careful not to concatenate the header and the payload
+        # prior to calling 'write' as we do not want to allocate a large
+        # temporary bytes object.
+        # We intentionally do not insert a protocol 4 frame opcode to make
+        # it possible to optimize file.read calls in the loader.
+        write(header)
+        write(payload)
+
+
+class _Unframer:
+
+    def __init__(self, file_read, file_readline, file_tell=None):
+        self.file_read = file_read
+        self.file_readline = file_readline
+        self.current_frame = None
+
+    def readinto(self, buf):
+        if self.current_frame:
+            n = self.current_frame.readinto(buf)
+            if n == 0 and len(buf) != 0:
+                self.current_frame = None
+                n = len(buf)
+                buf[:] = self.file_read(n)
+                return n
+            if n < len(buf):
+                raise UnpicklingError(
+                    "pickle exhausted before end of frame")
+            return n
+        else:
+            n = len(buf)
+            buf[:] = self.file_read(n)
+            return n
+
+    def read(self, n):
+        if self.current_frame:
+            data = self.current_frame.read(n)
+            if not data and n != 0:
+                self.current_frame = None
+                return self.file_read(n)
+            if len(data) < n:
+                raise UnpicklingError(
+                    "pickle exhausted before end of frame")
+            return data
+        else:
+            return self.file_read(n)
+
+    def readline(self):
+        if self.current_frame:
+            data = self.current_frame.readline()
+            if not data:
+                self.current_frame = None
+                return self.file_readline()
+            if data[-1] != b'\n'[0]:
+                raise UnpicklingError(
+                    "pickle exhausted before end of frame")
+            return data
+        else:
+            return self.file_readline()
+
+    def load_frame(self, frame_size):
+        if self.current_frame and self.current_frame.read() != b'':
+            raise UnpicklingError(
+                "beginning of a new frame before end of current frame")
+        self.current_frame = io.BytesIO(self.file_read(frame_size))
+
+
+# Tools used for pickling.
+
+def _getattribute(obj, name):
+    for subpath in name.split('.'):
+        if subpath == '<locals>':
+            raise AttributeError("Can't get local attribute {!r} on {!r}"
+                                 .format(name, obj))
+        try:
+            parent = obj
+            obj = getattr(obj, subpath)
+        except AttributeError:
+            raise AttributeError("Can't get attribute {!r} on {!r}"
+                                 .format(name, obj)) from None
+    return obj, parent
+
+def whichmodule(obj, name):
+    """Find the module an object belong to."""
+    module_name = getattr(obj, '__module__', None)
+    if module_name is not None:
+        return module_name
+    # Protect the iteration by using a list copy of sys.modules against dynamic
+    # modules that trigger imports of other modules upon calls to getattr.
+    for module_name, module in sys.modules.copy().items():
+        if (module_name == '__main__'
+            or module_name == '__mp_main__'  # bpo-42406
+            or module is None):
+            continue
+        try:
+            if _getattribute(module, name)[0] is obj:
+                return module_name
+        except AttributeError:
+            pass
+    return '__main__'
+
+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''
+    nbytes = (x.bit_length() >> 3) + 1
+    result = x.to_bytes(nbytes, byteorder='little', signed=True)
+    if x < 0 and nbytes > 1:
+        if result[-1] == 0xff and (result[-2] & 0x80) != 0:
+            result = result[:-1]
+    return result
+
+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
+    """
+    return int.from_bytes(data, byteorder='little', signed=True)
+
+
+# Pickling machinery
+
+class _Pickler:
+
+    def __init__(self, file, protocol=None, *, fix_imports=True,
+                 buffer_callback=None):
+        """This takes a binary file for writing a pickle data stream.
+
+        The optional *protocol* argument tells the pickler to use the
+        given protocol; supported protocols are 0, 1, 2, 3, 4 and 5.
+        The default protocol is 4. It was introduced in Python 3.4, and
+        is incompatible with previous versions.
+
+        Specifying a negative protocol version selects the highest
+        protocol version supported.  The higher the protocol used, the
+        more recent the version of Python needed to read the pickle
+        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, an io.BytesIO instance, or any other custom
+        object that meets this interface.
+
+        If *fix_imports* is True and *protocol* is less than 3, pickle
+        will try to map the new Python 3 names to the old module names
+        used in Python 2, so that the pickle data stream is readable
+        with Python 2.
+
+        If *buffer_callback* is None (the default), buffer views are
+        serialized into *file* as part of the pickle stream.
+
+        If *buffer_callback* is not None, then it can be called any number
+        of times with a buffer view.  If the callback returns a false value
+        (such as None), the given buffer is out-of-band; otherwise the
+        buffer is serialized in-band, i.e. inside the pickle stream.
+
+        It is an error if *buffer_callback* is not None and *protocol*
+        is None or smaller than 5.
+        """
+        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)
+        if buffer_callback is not None and protocol < 5:
+            raise ValueError("buffer_callback needs protocol >= 5")
+        self._buffer_callback = buffer_callback
+        try:
+            self._file_write = file.write
+        except AttributeError:
+            raise TypeError("file must have a 'write' attribute")
+        self.framer = _Framer(self._file_write)
+        self.write = self.framer.write
+        self._write_large_bytes = self.framer.write_large_bytes
+        self.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, "_file_write"):
+            raise PicklingError("Pickler.__init__() was not called by "
+                                "%s.__init__()" % (self.__class__.__name__,))
+        if self.proto >= 2:
+            self.write(PROTO + pack("<B", self.proto))
+        if self.proto >= 4:
+            self.framer.start_framing()
+        self.save(obj)
+        self.write(STOP)
+        self.framer.end_framing()
+
+    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
+        idx = len(self.memo)
+        self.write(self.put(idx))
+        self.memo[id(obj)] = idx, obj
+
+    # Return a PUT (BINPUT, LONG_BINPUT) opcode string, with argument i.
+    def put(self, idx):
+        if self.proto >= 4:
+            return MEMOIZE
+        elif self.bin:
+            if idx < 256:
+                return BINPUT + pack("<B", idx)
+            else:
+                return LONG_BINPUT + pack("<I", idx)
+        else:
+            return PUT + repr(idx).encode("ascii") + b'\n'
+
+    # Return a GET (BINGET, LONG_BINGET) opcode string, with argument i.
+    def get(self, i):
+        if self.bin:
+            if i < 256:
+                return BINGET + pack("<B", i)
+            else:
+                return LONG_BINGET + pack("<I", i)
+
+        return GET + repr(i).encode("ascii") + b'\n'
+
+    def save(self, obj, save_persistent_id=True):
+        self.framer.commit_frame()
+
+        # 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 is not None:
+            self.write(self.get(x[0]))
+            return
+
+        rv = NotImplemented
+        reduce = getattr(self, "reducer_override", None)
+        if reduce is not None:
+            rv = reduce(obj)
+
+        if rv is NotImplemented:
+            # Check the type dispatch table
+            t = type(obj)
+            f = self.dispatch.get(t)
+            if f is not None:
+                f(self, obj)  # Call unbound method with explicit self
+                return
+
+            # Check private dispatch table if any, or else
+            # copyreg.dispatch_table
+            reduce = getattr(self, 'dispatch_table', dispatch_table).get(t)
+            if reduce is not None:
+                rv = reduce(obj)
+            else:
+                # Check for a class with a custom metaclass; treat as regular
+                # class
+                if issubclass(t, type):
+                    self.save_global(obj)
+                    return
+
+                # Check for a __reduce_ex__ method, fall back to __reduce__
+                reduce = getattr(obj, "__reduce_ex__", None)
+                if reduce is not None:
+                    rv = reduce(self.proto)
+                else:
+                    reduce = getattr(obj, "__reduce__", None)
+                    if reduce is not None:
+                        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 <= 6):
+            raise PicklingError("Tuple returned by %s must have "
+                                "two to six 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:
+            try:
+                self.write(PERSID + str(pid).encode("ascii") + b'\n')
+            except UnicodeEncodeError:
+                raise PicklingError(
+                    "persistent IDs in protocol 0 must be ASCII strings")
+
+    def save_reduce(self, func, args, state=None, listitems=None,
+                    dictitems=None, state_setter=None, *, obj=None):
+        # This API is called by some subclasses
+
+        if not isinstance(args, tuple):
+            raise PicklingError("args from save_reduce() must be a tuple")
+        if not callable(func):
+            raise PicklingError("func from save_reduce() must be callable")
+
+        save = self.save
+        write = self.write
+
+        func_name = getattr(func, "__name__", "")
+        if self.proto >= 2 and func_name == "__newobj_ex__":
+            cls, args, kwargs = args
+            if not hasattr(cls, "__new__"):
+                raise PicklingError("args[0] from {} args has no __new__"
+                                    .format(func_name))
+            if obj is not None and cls is not obj.__class__:
+                raise PicklingError("args[0] from {} args has the wrong class"
+                                    .format(func_name))
+            if self.proto >= 4:
+                save(cls)
+                save(args)
+                save(kwargs)
+                write(NEWOBJ_EX)
+            else:
+                func = partial(cls.__new__, cls, *args, **kwargs)
+                save(func)
+                save(())
+                write(REDUCE)
+        elif self.proto >= 2 and func_name == "__newobj__":
+            # A __reduce__ implementation can direct protocol 2 or newer 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
+            # 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:
+            # If the object is already in the memo, this means it is
+            # recursive. In this case, throw away everything we put on the
+            # stack, and fetch the object back from the memo.
+            if id(obj) in self.memo:
+                write(POP + self.get(self.memo[id(obj)][0]))
+            else:
+                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:
+            if state_setter is None:
+                save(state)
+                write(BUILD)
+            else:
+                # If a state_setter is specified, call it instead of load_build
+                # to update obj's with its previous state.
+                # First, push state_setter and its tuple of expected arguments
+                # (obj, state) onto the stack.
+                save(state_setter)
+                save(obj)  # simple BINGET opcode as obj is already memoized.
+                save(state)
+                write(TUPLE2)
+                # Trigger a state_setter(obj, state) function call.
+                write(REDUCE)
+                # The purpose of state_setter is to carry-out an
+                # inplace modification of obj. We do not care about what the
+                # method might return, so its output is eventually removed from
+                # the stack.
+                write(POP)
+
+    # 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(NEWTRUE if obj else NEWFALSE)
+        else:
+            self.write(TRUE if obj else FALSE)
+    dispatch[bool] = save_bool
+
+    def save_long(self, obj):
+        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 + pack("<B", obj))
+                    return
+                if obj <= 0xffff:
+                    self.write(BININT2 + pack("<H", obj))
+                    return
+            # Next check for 4-byte signed ints:
+            if -0x80000000 <= obj <= 0x7fffffff:
+                self.write(BININT + pack("<i", obj))
+                return
+        if self.proto >= 2:
+            encoded = encode_long(obj)
+            n = len(encoded)
+            if n < 256:
+                self.write(LONG1 + pack("<B", n) + encoded)
+            else:
+                self.write(LONG4 + pack("<i", n) + encoded)
+            return
+        if -0x80000000 <= obj <= 0x7fffffff:
+            self.write(INT + repr(obj).encode("ascii") + b'\n')
+        else:
+            self.write(LONG + repr(obj).encode("ascii") + b'L\n')
+    dispatch[int] = save_long
+
+    def save_float(self, obj):
+        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):
+        if self.proto < 3:
+            if not obj: # bytes object is empty
+                self.save_reduce(bytes, (), obj=obj)
+            else:
+                self.save_reduce(codecs.encode,
+                                 (str(obj, 'latin1'), 'latin1'), obj=obj)
+            return
+        n = len(obj)
+        if n <= 0xff:
+            self.write(SHORT_BINBYTES + pack("<B", n) + obj)
+        elif n > 0xffffffff and self.proto >= 4:
+            self._write_large_bytes(BINBYTES8 + pack("<Q", n), obj)
+        elif n >= self.framer._FRAME_SIZE_TARGET:
+            self._write_large_bytes(BINBYTES + pack("<I", n), obj)
+        else:
+            self.write(BINBYTES + pack("<I", n) + obj)
+        self.memoize(obj)
+    dispatch[bytes] = save_bytes
+
+    def save_bytearray(self, obj):
+        if self.proto < 5:
+            if not obj:  # bytearray is empty
+                self.save_reduce(bytearray, (), obj=obj)
+            else:
+                self.save_reduce(bytearray, (bytes(obj),), obj=obj)
+            return
+        n = len(obj)
+        if n >= self.framer._FRAME_SIZE_TARGET:
+            self._write_large_bytes(BYTEARRAY8 + pack("<Q", n), obj)
+        else:
+            self.write(BYTEARRAY8 + pack("<Q", n) + obj)
+        self.memoize(obj)
+    dispatch[bytearray] = save_bytearray
+
+    if _HAVE_PICKLE_BUFFER:
+        def save_picklebuffer(self, obj):
+            if self.proto < 5:
+                raise PicklingError("PickleBuffer can only pickled with "
+                                    "protocol >= 5")
+            with obj.raw() as m:
+                if not m.contiguous:
+                    raise PicklingError("PickleBuffer can not be pickled when "
+                                        "pointing to a non-contiguous buffer")
+                in_band = True
+                if self._buffer_callback is not None:
+                    in_band = bool(self._buffer_callback(obj))
+                if in_band:
+                    # Write data in-band
+                    # XXX The C implementation avoids a copy here
+                    if m.readonly:
+                        self.save_bytes(m.tobytes())
+                    else:
+                        self.save_bytearray(m.tobytes())
+                else:
+                    # Write data out-of-band
+                    self.write(NEXT_BUFFER)
+                    if m.readonly:
+                        self.write(READONLY_BUFFER)
+
+        dispatch[PickleBuffer] = save_picklebuffer
+
+    def save_str(self, obj):
+        if self.bin:
+            encoded = obj.encode('utf-8', 'surrogatepass')
+            n = len(encoded)
+            if n <= 0xff and self.proto >= 4:
+                self.write(SHORT_BINUNICODE + pack("<B", n) + encoded)
+            elif n > 0xffffffff and self.proto >= 4:
+                self._write_large_bytes(BINUNICODE8 + pack("<Q", n), encoded)
+            elif n >= self.framer._FRAME_SIZE_TARGET:
+                self._write_large_bytes(BINUNICODE + pack("<I", n), encoded)
+            else:
+                self.write(BINUNICODE + pack("<I", n) + encoded)
+        else:
+            obj = obj.replace("\\", "\\u005c")
+            obj = obj.replace("\0", "\\u0000")
+            obj = obj.replace("\n", "\\u000a")
+            obj = obj.replace("\r", "\\u000d")
+            obj = obj.replace("\x1a", "\\u001a")  # EOF on DOS
+            self.write(UNICODE + obj.encode('raw-unicode-escape') +
+                       b'\n')
+        self.memoize(obj)
+    dispatch[str] = save_str
+
+    def save_tuple(self, obj):
+        if not obj: # tuple is empty
+            if self.bin:
+                self.write(EMPTY_TUPLE)
+            else:
+                self.write(MARK + TUPLE)
+            return
+
+        n = len(obj)
+        save = self.save
+        memo = self.memo
+        if n <= 3 and self.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])
+                self.write(POP * n + get)
+            else:
+                self.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 = self.write
+        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 self.bin:
+                write(POP_MARK + get)
+            else:   # proto 0 -- POP_MARK not available
+                write(POP * (n+1) + get)
+            return
+
+        # No recursion.
+        write(TUPLE)
+        self.memoize(obj)
+
+    dispatch[tuple] = save_tuple
+
+    def save_list(self, obj):
+        if self.bin:
+            self.write(EMPTY_LIST)
+        else:   # proto 0 -- can't use EMPTY_LIST
+            self.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
+
+        it = iter(items)
+        while True:
+            tmp = list(islice(it, self._BATCHSIZE))
+            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
+            if n < self._BATCHSIZE:
+                return
+
+    def save_dict(self, obj):
+        if self.bin:
+            self.write(EMPTY_DICT)
+        else:   # proto 0 -- can't use EMPTY_DICT
+            self.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
+
+        it = iter(items)
+        while True:
+            tmp = list(islice(it, self._BATCHSIZE))
+            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
+            if n < self._BATCHSIZE:
+                return
+
+    def save_set(self, obj):
+        save = self.save
+        write = self.write
+
+        if self.proto < 4:
+            self.save_reduce(set, (list(obj),), obj=obj)
+            return
+
+        write(EMPTY_SET)
+        self.memoize(obj)
+
+        it = iter(obj)
+        while True:
+            batch = list(islice(it, self._BATCHSIZE))
+            n = len(batch)
+            if n > 0:
+                write(MARK)
+                for item in batch:
+                    save(item)
+                write(ADDITEMS)
+            if n < self._BATCHSIZE:
+                return
+    dispatch[set] = save_set
+
+    def save_frozenset(self, obj):
+        save = self.save
+        write = self.write
+
+        if self.proto < 4:
+            self.save_reduce(frozenset, (list(obj),), obj=obj)
+            return
+
+        write(MARK)
+        for item in obj:
+            save(item)
+
+        if id(obj) in self.memo:
+            # If the object is already in the memo, this means it is
+            # recursive. In this case, throw away everything we put on the
+            # stack, and fetch the object back from the memo.
+            write(POP_MARK + self.get(self.memo[id(obj)][0]))
+            return
+
+        write(FROZENSET)
+        self.memoize(obj)
+    dispatch[frozenset] = save_frozenset
+
+    def save_global(self, obj, name=None):
+        write = self.write
+        memo = self.memo
+
+        if name is None:
+            name = getattr(obj, '__qualname__', None)
+        if name is None:
+            name = obj.__name__
+
+        module_name = whichmodule(obj, name)
+        try:
+            __import__(module_name, level=0)
+            module = sys.modules[module_name]
+            obj2, parent = _getattribute(module, name)
+        except (ImportError, KeyError, AttributeError):
+            raise PicklingError(
+                "Can't pickle %r: it's not found as %s.%s" %
+                (obj, module_name, name)) from None
+        else:
+            if obj2 is not obj:
+                raise PicklingError(
+                    "Can't pickle %r: it's not the same object as %s.%s" %
+                    (obj, module_name, name))
+
+        if self.proto >= 2:
+            code = _extension_registry.get((module_name, name))
+            if code:
+                assert code > 0
+                if code <= 0xff:
+                    write(EXT1 + pack("<B", code))
+                elif code <= 0xffff:
+                    write(EXT2 + pack("<H", code))
+                else:
+                    write(EXT4 + pack("<i", code))
+                return
+        lastname = name.rpartition('.')[2]
+        if parent is module:
+            name = lastname
+        # Non-ASCII identifiers are supported only with protocols >= 3.
+        if self.proto >= 4:
+            self.save(module_name)
+            self.save(name)
+            write(STACK_GLOBAL)
+        elif parent is not module:
+            self.save_reduce(getattr, (parent, lastname))
+        elif self.proto >= 3:
+            write(GLOBAL + bytes(module_name, "utf-8") + b'\n' +
+                  bytes(name, "utf-8") + b'\n')
+        else:
+            if self.fix_imports:
+                r_name_mapping = _compat_pickle.REVERSE_NAME_MAPPING
+                r_import_mapping = _compat_pickle.REVERSE_IMPORT_MAPPING
+                if (module_name, name) in r_name_mapping:
+                    module_name, name = r_name_mapping[(module_name, name)]
+                elif module_name in r_import_mapping:
+                    module_name = r_import_mapping[module_name]
+            try:
+                write(GLOBAL + bytes(module_name, "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)) from None
+
+        self.memoize(obj)
+
+    def save_type(self, obj):
+        if obj is type(None):
+            return self.save_reduce(type, (None,), obj=obj)
+        elif obj is type(NotImplemented):
+            return self.save_reduce(type, (NotImplemented,), obj=obj)
+        elif obj is type(...):
+            return self.save_reduce(type, (...,), obj=obj)
+        return self.save_global(obj)
+
+    dispatch[FunctionType] = save_global
+    dispatch[type] = save_type
+
+
+# Unpickling machinery
+
+class _Unpickler:
+
+    def __init__(self, file, *, fix_imports=True,
+                 encoding="ASCII", errors="strict", buffers=None):
+        """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 argument *file* 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*
+        can be a binary file object opened for reading, an io.BytesIO
+        object, or any other custom object that meets this interface.
+
+        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.
+
+        If *buffers* is not None, it should be an iterable of buffer-enabled
+        objects that is consumed each time the pickle stream references
+        an out-of-band buffer view.  Such buffers have been given in order
+        to the *buffer_callback* of a Pickler object.
+
+        If *buffers* is None (the default), then the buffers are taken
+        from the pickle stream, assuming they are serialized there.
+        It is an error for *buffers* to be None if the pickle stream
+        was produced with a non-None *buffer_callback*.
+
+        Other optional arguments are *fix_imports*, *encoding* and
+        *errors*, which are used to control compatibility support for
+        pickle stream generated by Python 2.  If *fix_imports* is True,
+        pickle will try to map the old Python 2 names to the new names
+        used in Python 3.  The *encoding* and *errors* tell pickle how
+        to decode 8-bit string instances pickled by Python 2; these
+        default to 'ASCII' and 'strict', respectively. *encoding* can be
+        'bytes' to read these 8-bit string instances as bytes objects.
+        """
+        self._buffers = iter(buffers) if buffers is not None else None
+        self._file_readline = file.readline
+        self._file_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, "_file_read"):
+            raise UnpicklingError("Unpickler.__init__() was not called by "
+                                  "%s.__init__()" % (self.__class__.__name__,))
+        self._unframer = _Unframer(self._file_read, self._file_readline)
+        self.read = self._unframer.read
+        self.readinto = self._unframer.readinto
+        self.readline = self._unframer.readline
+        self.metastack = []
+        self.stack = []
+        self.append = self.stack.append
+        self.proto = 0
+        read = self.read
+        dispatch = self.dispatch
+        try:
+            while True:
+                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 a list of items pushed in the stack after last MARK instruction.
+    def pop_mark(self):
+        items = self.stack
+        self.stack = self.metastack.pop()
+        self.append = self.stack.append
+        return items
+
+    def persistent_load(self, pid):
+        raise UnpicklingError("unsupported persistent id encountered")
+
+    dispatch = {}
+
+    def load_proto(self):
+        proto = self.read(1)[0]
+        if not 0 <= proto <= HIGHEST_PROTOCOL:
+            raise ValueError("unsupported pickle protocol: %d" % proto)
+        self.proto = proto
+    dispatch[PROTO[0]] = load_proto
+
+    def load_frame(self):
+        frame_size, = unpack('<Q', self.read(8))
+        if frame_size > sys.maxsize:
+            raise ValueError("frame size > sys.maxsize: %d" % frame_size)
+        self._unframer.load_frame(frame_size)
+    dispatch[FRAME[0]] = load_frame
+
+    def load_persid(self):
+        try:
+            pid = self.readline()[:-1].decode("ascii")
+        except UnicodeDecodeError:
+            raise UnpicklingError(
+                "persistent IDs in protocol 0 must be ASCII strings")
+        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:
+            val = int(data, 0)
+        self.append(val)
+    dispatch[INT[0]] = load_int
+
+    def load_binint(self):
+        self.append(unpack('<i', self.read(4))[0])
+    dispatch[BININT[0]] = load_binint
+
+    def load_binint1(self):
+        self.append(self.read(1)[0])
+    dispatch[BININT1[0]] = load_binint1
+
+    def load_binint2(self):
+        self.append(unpack('<H', self.read(2))[0])
+    dispatch[BININT2[0]] = load_binint2
+
+    def load_long(self):
+        val = self.readline()[:-1]
+        if val and val[-1] == b'L'[0]:
+            val = val[:-1]
+        self.append(int(val, 0))
+    dispatch[LONG[0]] = load_long
+
+    def load_long1(self):
+        n = self.read(1)[0]
+        data = self.read(n)
+        self.append(decode_long(data))
+    dispatch[LONG1[0]] = load_long1
+
+    def load_long4(self):
+        n, = unpack('<i', self.read(4))
+        if n < 0:
+            # Corrupt or hostile pickle -- we never write one like this
+            raise UnpicklingError("LONG pickle has negative byte count")
+        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):
+        self.append(unpack('>d', self.read(8))[0])
+    dispatch[BINFLOAT[0]] = load_binfloat
+
+    def _decode_string(self, value):
+        # Used to allow strings from Python 2 to be decoded either as
+        # bytes or Unicode strings.  This should be used only with the
+        # STRING, BINSTRING and SHORT_BINSTRING opcodes.
+        if self.encoding == "bytes":
+            return value
+        else:
+            return value.decode(self.encoding, self.errors)
+
+    def load_string(self):
+        data = self.readline()[:-1]
+        # Strip outermost quotes
+        if len(data) >= 2 and data[0] == data[-1] and data[0] in b'"\'':
+            data = data[1:-1]
+        else:
+            raise UnpicklingError("the STRING opcode argument must be quoted")
+        self.append(self._decode_string(codecs.escape_decode(data)[0]))
+    dispatch[STRING[0]] = load_string
+
+    def load_binstring(self):
+        # Deprecated BINSTRING uses signed 32-bit length
+        len, = unpack('<i', self.read(4))
+        if len < 0:
+            raise UnpicklingError("BINSTRING pickle has negative byte count")
+        data = self.read(len)
+        self.append(self._decode_string(data))
+    dispatch[BINSTRING[0]] = load_binstring
+
+    def load_binbytes(self):
+        len, = unpack('<I', self.read(4))
+        if len > maxsize:
+            raise UnpicklingError("BINBYTES exceeds system's maximum size "
+                                  "of %d bytes" % maxsize)
+        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, = unpack('<I', self.read(4))
+        if len > maxsize:
+            raise UnpicklingError("BINUNICODE exceeds system's maximum size "
+                                  "of %d bytes" % maxsize)
+        self.append(str(self.read(len), 'utf-8', 'surrogatepass'))
+    dispatch[BINUNICODE[0]] = load_binunicode
+
+    def load_binunicode8(self):
+        len, = unpack('<Q', self.read(8))
+        if len > maxsize:
+            raise UnpicklingError("BINUNICODE8 exceeds system's maximum size "
+                                  "of %d bytes" % maxsize)
+        self.append(str(self.read(len), 'utf-8', 'surrogatepass'))
+    dispatch[BINUNICODE8[0]] = load_binunicode8
+
+    def load_binbytes8(self):
+        len, = unpack('<Q', self.read(8))
+        if len > maxsize:
+            raise UnpicklingError("BINBYTES8 exceeds system's maximum size "
+                                  "of %d bytes" % maxsize)
+        self.append(self.read(len))
+    dispatch[BINBYTES8[0]] = load_binbytes8
+
+    def load_bytearray8(self):
+        len, = unpack('<Q', self.read(8))
+        if len > maxsize:
+            raise UnpicklingError("BYTEARRAY8 exceeds system's maximum size "
+                                  "of %d bytes" % maxsize)
+        b = bytearray(len)
+        self.readinto(b)
+        self.append(b)
+    dispatch[BYTEARRAY8[0]] = load_bytearray8
+
+    def load_next_buffer(self):
+        if self._buffers is None:
+            raise UnpicklingError("pickle stream refers to out-of-band data "
+                                  "but no *buffers* argument was given")
+        try:
+            buf = next(self._buffers)
+        except StopIteration:
+            raise UnpicklingError("not enough out-of-band buffers")
+        self.append(buf)
+    dispatch[NEXT_BUFFER[0]] = load_next_buffer
+
+    def load_readonly_buffer(self):
+        buf = self.stack[-1]
+        with memoryview(buf) as m:
+            if not m.readonly:
+                self.stack[-1] = m.toreadonly()
+    dispatch[READONLY_BUFFER[0]] = load_readonly_buffer
+
+    def load_short_binstring(self):
+        len = self.read(1)[0]
+        data = self.read(len)
+        self.append(self._decode_string(data))
+    dispatch[SHORT_BINSTRING[0]] = load_short_binstring
+
+    def load_short_binbytes(self):
+        len = self.read(1)[0]
+        self.append(self.read(len))
+    dispatch[SHORT_BINBYTES[0]] = load_short_binbytes
+
+    def load_short_binunicode(self):
+        len = self.read(1)[0]
+        self.append(str(self.read(len), 'utf-8', 'surrogatepass'))
+    dispatch[SHORT_BINUNICODE[0]] = load_short_binunicode
+
+    def load_tuple(self):
+        items = self.pop_mark()
+        self.append(tuple(items))
+    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_empty_set(self):
+        self.append(set())
+    dispatch[EMPTY_SET[0]] = load_empty_set
+
+    def load_frozenset(self):
+        items = self.pop_mark()
+        self.append(frozenset(items))
+    dispatch[FROZENSET[0]] = load_frozenset
+
+    def load_list(self):
+        items = self.pop_mark()
+        self.append(items)
+    dispatch[LIST[0]] = load_list
+
+    def load_dict(self):
+        items = self.pop_mark()
+        d = {items[i]: items[i+1]
+             for i in range(0, len(items), 2)}
+        self.append(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, args):
+        if (args or not isinstance(klass, type) or
+            hasattr(klass, "__getinitargs__")):
+            try:
+                value = klass(*args)
+            except TypeError as err:
+                raise TypeError("in constructor for %s: %s" %
+                                (klass.__name__, str(err)), sys.exc_info()[2])
+        else:
+            value = klass.__new__(klass)
+        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.pop_mark())
+    dispatch[INST[0]] = load_inst
+
+    def load_obj(self):
+        # Stack is ... markobject classobject arg1 arg2 ...
+        args = self.pop_mark()
+        cls = args.pop(0)
+        self._instantiate(cls, args)
+    dispatch[OBJ[0]] = load_obj
+
+    def load_newobj(self):
+        args = self.stack.pop()
+        cls = self.stack.pop()
+        obj = cls.__new__(cls, *args)
+        self.append(obj)
+    dispatch[NEWOBJ[0]] = load_newobj
+
+    def load_newobj_ex(self):
+        kwargs = self.stack.pop()
+        args = self.stack.pop()
+        cls = self.stack.pop()
+        obj = cls.__new__(cls, *args, **kwargs)
+        self.append(obj)
+    dispatch[NEWOBJ_EX[0]] = load_newobj_ex
+
+    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_stack_global(self):
+        name = self.stack.pop()
+        module = self.stack.pop()
+        if type(name) is not str or type(module) is not str:
+            raise UnpicklingError("STACK_GLOBAL requires str")
+        self.append(self.find_class(module, name))
+    dispatch[STACK_GLOBAL[0]] = load_stack_global
+
+    def load_ext1(self):
+        code = self.read(1)[0]
+        self.get_extension(code)
+    dispatch[EXT1[0]] = load_ext1
+
+    def load_ext2(self):
+        code, = unpack('<H', self.read(2))
+        self.get_extension(code)
+    dispatch[EXT2[0]] = load_ext2
+
+    def load_ext4(self):
+        code, = unpack('<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:
+            if code <= 0: # note that 0 is forbidden
+                # Corrupt or hostile pickle.
+                raise UnpicklingError("EXT specifies code <= 0")
+            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.
+        sys.audit('pickle.find_class', module, name)
+        if self.proto < 3 and self.fix_imports:
+            if (module, name) in _compat_pickle.NAME_MAPPING:
+                module, name = _compat_pickle.NAME_MAPPING[(module, name)]
+            elif module in _compat_pickle.IMPORT_MAPPING:
+                module = _compat_pickle.IMPORT_MAPPING[module]
+        __import__(module, level=0)
+        if self.proto >= 4:
+            return _getattribute(sys.modules[module], name)[0]
+        else:
+            return getattr(sys.modules[module], name)
+
+    def load_reduce(self):
+        stack = self.stack
+        args = stack.pop()
+        func = stack[-1]
+        stack[-1] = func(*args)
+    dispatch[REDUCE[0]] = load_reduce
+
+    def load_pop(self):
+        if self.stack:
+            del self.stack[-1]
+        else:
+            self.pop_mark()
+    dispatch[POP[0]] = load_pop
+
+    def load_pop_mark(self):
+        self.pop_mark()
+    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])
+        try:
+            self.append(self.memo[i])
+        except KeyError:
+            msg = f'Memo value not found at index {i}'
+            raise UnpicklingError(msg) from None
+    dispatch[GET[0]] = load_get
+
+    def load_binget(self):
+        i = self.read(1)[0]
+        try:
+            self.append(self.memo[i])
+        except KeyError as exc:
+            msg = f'Memo value not found at index {i}'
+            raise UnpicklingError(msg) from None
+    dispatch[BINGET[0]] = load_binget
+
+    def load_long_binget(self):
+        i, = unpack('<I', self.read(4))
+        try:
+            self.append(self.memo[i])
+        except KeyError as exc:
+            msg = f'Memo value not found at index {i}'
+            raise UnpicklingError(msg) from None
+    dispatch[LONG_BINGET[0]] = load_long_binget
+
+    def load_put(self):
+        i = int(self.readline()[:-1])
+        if i < 0:
+            raise ValueError("negative PUT argument")
+        self.memo[i] = self.stack[-1]
+    dispatch[PUT[0]] = load_put
+
+    def load_binput(self):
+        i = self.read(1)[0]
+        if i < 0:
+            raise ValueError("negative BINPUT argument")
+        self.memo[i] = self.stack[-1]
+    dispatch[BINPUT[0]] = load_binput
+
+    def load_long_binput(self):
+        i, = unpack('<I', self.read(4))
+        if i > maxsize:
+            raise ValueError("negative LONG_BINPUT argument")
+        self.memo[i] = self.stack[-1]
+    dispatch[LONG_BINPUT[0]] = load_long_binput
+
+    def load_memoize(self):
+        memo = self.memo
+        memo[len(memo)] = self.stack[-1]
+    dispatch[MEMOIZE[0]] = load_memoize
+
+    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):
+        items = self.pop_mark()
+        list_obj = self.stack[-1]
+        try:
+            extend = list_obj.extend
+        except AttributeError:
+            pass
+        else:
+            extend(items)
+            return
+        # Even if the PEP 307 requires extend() and append() methods,
+        # fall back on append() if the object has no extend() method
+        # for backward compatibility.
+        append = list_obj.append
+        for item in items:
+            append(item)
+    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):
+        items = self.pop_mark()
+        dict = self.stack[-1]
+        for i in range(0, len(items), 2):
+            dict[items[i]] = items[i + 1]
+    dispatch[SETITEMS[0]] = load_setitems
+
+    def load_additems(self):
+        items = self.pop_mark()
+        set_obj = self.stack[-1]
+        if isinstance(set_obj, set):
+            set_obj.update(items)
+        else:
+            add = set_obj.add
+            for item in items:
+                add(item)
+    dispatch[ADDITEMS[0]] = load_additems
+
+    def load_build(self):
+        stack = self.stack
+        state = stack.pop()
+        inst = stack[-1]
+        setstate = getattr(inst, "__setstate__", None)
+        if setstate is not None:
+            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.metastack.append(self.stack)
+        self.stack = []
+        self.append = self.stack.append
+    dispatch[MARK[0]] = load_mark
+
+    def load_stop(self):
+        value = self.stack.pop()
+        raise _Stop(value)
+    dispatch[STOP[0]] = load_stop
+
+
+# Shorthands
+
+def _dump(obj, file, protocol=None, *, fix_imports=True, buffer_callback=None):
+    _Pickler(file, protocol, fix_imports=fix_imports,
+             buffer_callback=buffer_callback).dump(obj)
+
+def _dumps(obj, protocol=None, *, fix_imports=True, buffer_callback=None):
+    f = io.BytesIO()
+    _Pickler(f, protocol, fix_imports=fix_imports,
+             buffer_callback=buffer_callback).dump(obj)
+    res = f.getvalue()
+    assert isinstance(res, bytes_types)
+    return res
+
+def _load(file, *, fix_imports=True, encoding="ASCII", errors="strict",
+          buffers=None):
+    return _Unpickler(file, fix_imports=fix_imports, buffers=buffers,
+                     encoding=encoding, errors=errors).load()
+
+def _loads(s, /, *, fix_imports=True, encoding="ASCII", errors="strict",
+           buffers=None):
+    if isinstance(s, str):
+        raise TypeError("Can't load pickle from unicode string")
+    file = io.BytesIO(s)
+    return _Unpickler(file, fix_imports=fix_imports, buffers=buffers,
+                      encoding=encoding, errors=errors).load()
+
+# Use the faster _pickle if possible
+try:
+    from _pickle import (
+        PickleError,
+        PicklingError,
+        UnpicklingError,
+        Pickler,
+        Unpickler,
+        dump,
+        dumps,
+        load,
+        loads
+    )
+except ImportError:
+    Pickler, Unpickler = _Pickler, _Unpickler
+    dump, dumps, load, loads = _dump, _dumps, _load, _loads
+
+# Doctest
+def _test():
+    import doctest
+    return doctest.testmod()
+
+if __name__ == "__main__":
+    import argparse
+    parser = argparse.ArgumentParser(
+        description='display contents of the pickle files')
+    parser.add_argument(
+        'pickle_file', type=argparse.FileType('br'),
+        nargs='*', help='the pickle file')
+    parser.add_argument(
+        '-t', '--test', action='store_true',
+        help='run self-test suite')
+    parser.add_argument(
+        '-v', action='store_true',
+        help='run verbosely; only affects self-test run')
+    args = parser.parse_args()
+    if args.test:
+        _test()
+    else:
+        if not args.pickle_file:
+            parser.print_help()
+        else:
+            import pprint
+            for f in args.pickle_file:
+                obj = load(f)
+                pprint.pprint(obj)