--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/pip/_vendor/msgpack/fallback.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,1027 @@
+"""Fallback pure Python implementation of msgpack"""
+
+import sys
+import struct
+import warnings
+
+
+if sys.version_info[0] == 2:
+    PY2 = True
+    int_types = (int, long)
+    def dict_iteritems(d):
+        return d.iteritems()
+else:
+    PY2 = False
+    int_types = int
+    unicode = str
+    xrange = range
+    def dict_iteritems(d):
+        return d.items()
+
+if sys.version_info < (3, 5):
+    # Ugly hack...
+    RecursionError = RuntimeError
+
+    def _is_recursionerror(e):
+        return len(e.args) == 1 and isinstance(e.args[0], str) and \
+            e.args[0].startswith('maximum recursion depth exceeded')
+else:
+    def _is_recursionerror(e):
+        return True
+
+if hasattr(sys, 'pypy_version_info'):
+    # cStringIO is slow on PyPy, StringIO is faster.  However: PyPy's own
+    # StringBuilder is fastest.
+    from __pypy__ import newlist_hint
+    try:
+        from __pypy__.builders import BytesBuilder as StringBuilder
+    except ImportError:
+        from __pypy__.builders import StringBuilder
+    USING_STRINGBUILDER = True
+    class StringIO(object):
+        def __init__(self, s=b''):
+            if s:
+                self.builder = StringBuilder(len(s))
+                self.builder.append(s)
+            else:
+                self.builder = StringBuilder()
+        def write(self, s):
+            if isinstance(s, memoryview):
+                s = s.tobytes()
+            elif isinstance(s, bytearray):
+                s = bytes(s)
+            self.builder.append(s)
+        def getvalue(self):
+            return self.builder.build()
+else:
+    USING_STRINGBUILDER = False
+    from io import BytesIO as StringIO
+    newlist_hint = lambda size: []
+
+
+from .exceptions import (
+    BufferFull,
+    OutOfData,
+    ExtraData,
+    FormatError,
+    StackError,
+)
+
+from . import ExtType
+
+
+EX_SKIP                 = 0
+EX_CONSTRUCT            = 1
+EX_READ_ARRAY_HEADER    = 2
+EX_READ_MAP_HEADER      = 3
+
+TYPE_IMMEDIATE          = 0
+TYPE_ARRAY              = 1
+TYPE_MAP                = 2
+TYPE_RAW                = 3
+TYPE_BIN                = 4
+TYPE_EXT                = 5
+
+DEFAULT_RECURSE_LIMIT = 511
+
+
+def _check_type_strict(obj, t, type=type, tuple=tuple):
+    if type(t) is tuple:
+        return type(obj) in t
+    else:
+        return type(obj) is t
+
+
+def _get_data_from_buffer(obj):
+    try:
+        view = memoryview(obj)
+    except TypeError:
+        # try to use legacy buffer protocol if 2.7, otherwise re-raise
+        if PY2:
+            view = memoryview(buffer(obj))
+            warnings.warn("using old buffer interface to unpack %s; "
+                          "this leads to unpacking errors if slicing is used and "
+                          "will be removed in a future version" % type(obj),
+                          RuntimeWarning, stacklevel=3)
+        else:
+            raise
+    if view.itemsize != 1:
+        raise ValueError("cannot unpack from multi-byte object")
+    return view
+
+
+def unpack(stream, **kwargs):
+    warnings.warn(
+        "Direct calling implementation's unpack() is deprecated, Use msgpack.unpack() or unpackb() instead.",
+        DeprecationWarning, stacklevel=2)
+    data = stream.read()
+    return unpackb(data, **kwargs)
+
+
+def unpackb(packed, **kwargs):
+    """
+    Unpack an object from `packed`.
+
+    Raises ``ExtraData`` when *packed* contains extra bytes.
+    Raises ``ValueError`` when *packed* is incomplete.
+    Raises ``FormatError`` when *packed* is not valid msgpack.
+    Raises ``StackError`` when *packed* contains too nested.
+    Other exceptions can be raised during unpacking.
+
+    See :class:`Unpacker` for options.
+    """
+    unpacker = Unpacker(None, max_buffer_size=len(packed), **kwargs)
+    unpacker.feed(packed)
+    try:
+        ret = unpacker._unpack()
+    except OutOfData:
+        raise ValueError("Unpack failed: incomplete input")
+    except RecursionError as e:
+        if _is_recursionerror(e):
+            raise StackError
+        raise
+    if unpacker._got_extradata():
+        raise ExtraData(ret, unpacker._get_extradata())
+    return ret
+
+
+if sys.version_info < (2, 7, 6):
+    def _unpack_from(f, b, o=0):
+        """Explicit typcast for legacy struct.unpack_from"""
+        return struct.unpack_from(f, bytes(b), o)
+else:
+    _unpack_from = struct.unpack_from
+
+
+class Unpacker(object):
+    """Streaming unpacker.
+
+    arguments:
+
+    :param file_like:
+        File-like object having `.read(n)` method.
+        If specified, unpacker reads serialized data from it and :meth:`feed()` is not usable.
+
+    :param int read_size:
+        Used as `file_like.read(read_size)`. (default: `min(16*1024, max_buffer_size)`)
+
+    :param bool use_list:
+        If true, unpack msgpack array to Python list.
+        Otherwise, unpack to Python tuple. (default: True)
+
+    :param bool raw:
+        If true, unpack msgpack raw to Python bytes (default).
+        Otherwise, unpack to Python str (or unicode on Python 2) by decoding
+        with UTF-8 encoding (recommended).
+        Currently, the default is true, but it will be changed to false in
+        near future.  So you must specify it explicitly for keeping backward
+        compatibility.
+
+        *encoding* option which is deprecated overrides this option.
+
+    :param bool strict_map_key:
+        If true, only str or bytes are accepted for map (dict) keys.
+        It's False by default for backward-compatibility.
+        But it will be True from msgpack 1.0.
+
+    :param callable object_hook:
+        When specified, it should be callable.
+        Unpacker calls it with a dict argument after unpacking msgpack map.
+        (See also simplejson)
+
+    :param callable object_pairs_hook:
+        When specified, it should be callable.
+        Unpacker calls it with a list of key-value pairs after unpacking msgpack map.
+        (See also simplejson)
+
+    :param str encoding:
+        Encoding used for decoding msgpack raw.
+        If it is None (default), msgpack raw is deserialized to Python bytes.
+
+    :param str unicode_errors:
+        (deprecated) Used for decoding msgpack raw with *encoding*.
+        (default: `'strict'`)
+
+    :param int max_buffer_size:
+        Limits size of data waiting unpacked.  0 means system's INT_MAX (default).
+        Raises `BufferFull` exception when it is insufficient.
+        You should set this parameter when unpacking data from untrusted source.
+
+    :param int max_str_len:
+        Deprecated, use *max_buffer_size* instead.
+        Limits max length of str. (default: max_buffer_size or 1024*1024)
+
+    :param int max_bin_len:
+        Deprecated, use *max_buffer_size* instead.
+        Limits max length of bin. (default: max_buffer_size or 1024*1024)
+
+    :param int max_array_len:
+        Limits max length of array.
+        (default: max_buffer_size or 128*1024)
+
+    :param int max_map_len:
+        Limits max length of map.
+        (default: max_buffer_size//2 or 32*1024)
+
+    :param int max_ext_len:
+        Deprecated, use *max_buffer_size* instead.
+        Limits max size of ext type.  (default: max_buffer_size or 1024*1024)
+
+    Example of streaming deserialize from file-like object::
+
+        unpacker = Unpacker(file_like, raw=False, max_buffer_size=10*1024*1024)
+        for o in unpacker:
+            process(o)
+
+    Example of streaming deserialize from socket::
+
+        unpacker = Unpacker(raw=False, max_buffer_size=10*1024*1024)
+        while True:
+            buf = sock.recv(1024**2)
+            if not buf:
+                break
+            unpacker.feed(buf)
+            for o in unpacker:
+                process(o)
+
+    Raises ``ExtraData`` when *packed* contains extra bytes.
+    Raises ``OutOfData`` when *packed* is incomplete.
+    Raises ``FormatError`` when *packed* is not valid msgpack.
+    Raises ``StackError`` when *packed* contains too nested.
+    Other exceptions can be raised during unpacking.
+    """
+
+    def __init__(self, file_like=None, read_size=0, use_list=True, raw=True, strict_map_key=False,
+                 object_hook=None, object_pairs_hook=None, list_hook=None,
+                 encoding=None, unicode_errors=None, max_buffer_size=0,
+                 ext_hook=ExtType,
+                 max_str_len=-1,
+                 max_bin_len=-1,
+                 max_array_len=-1,
+                 max_map_len=-1,
+                 max_ext_len=-1):
+        if encoding is not None:
+            warnings.warn(
+                "encoding is deprecated, Use raw=False instead.",
+                DeprecationWarning, stacklevel=2)
+
+        if unicode_errors is None:
+            unicode_errors = 'strict'
+
+        if file_like is None:
+            self._feeding = True
+        else:
+            if not callable(file_like.read):
+                raise TypeError("`file_like.read` must be callable")
+            self.file_like = file_like
+            self._feeding = False
+
+        #: array of bytes fed.
+        self._buffer = bytearray()
+        #: Which position we currently reads
+        self._buff_i = 0
+
+        # When Unpacker is used as an iterable, between the calls to next(),
+        # the buffer is not "consumed" completely, for efficiency sake.
+        # Instead, it is done sloppily.  To make sure we raise BufferFull at
+        # the correct moments, we have to keep track of how sloppy we were.
+        # Furthermore, when the buffer is incomplete (that is: in the case
+        # we raise an OutOfData) we need to rollback the buffer to the correct
+        # state, which _buf_checkpoint records.
+        self._buf_checkpoint = 0
+
+        if max_str_len == -1:
+            max_str_len = max_buffer_size or 1024*1024
+        if max_bin_len == -1:
+            max_bin_len = max_buffer_size or 1024*1024
+        if max_array_len == -1:
+            max_array_len = max_buffer_size or 128*1024
+        if max_map_len == -1:
+            max_map_len = max_buffer_size//2 or 32*1024
+        if max_ext_len == -1:
+            max_ext_len = max_buffer_size or 1024*1024
+
+        self._max_buffer_size = max_buffer_size or 2**31-1
+        if read_size > self._max_buffer_size:
+            raise ValueError("read_size must be smaller than max_buffer_size")
+        self._read_size = read_size or min(self._max_buffer_size, 16*1024)
+        self._raw = bool(raw)
+        self._strict_map_key = bool(strict_map_key)
+        self._encoding = encoding
+        self._unicode_errors = unicode_errors
+        self._use_list = use_list
+        self._list_hook = list_hook
+        self._object_hook = object_hook
+        self._object_pairs_hook = object_pairs_hook
+        self._ext_hook = ext_hook
+        self._max_str_len = max_str_len
+        self._max_bin_len = max_bin_len
+        self._max_array_len = max_array_len
+        self._max_map_len = max_map_len
+        self._max_ext_len = max_ext_len
+        self._stream_offset = 0
+
+        if list_hook is not None and not callable(list_hook):
+            raise TypeError('`list_hook` is not callable')
+        if object_hook is not None and not callable(object_hook):
+            raise TypeError('`object_hook` is not callable')
+        if object_pairs_hook is not None and not callable(object_pairs_hook):
+            raise TypeError('`object_pairs_hook` is not callable')
+        if object_hook is not None and object_pairs_hook is not None:
+            raise TypeError("object_pairs_hook and object_hook are mutually "
+                            "exclusive")
+        if not callable(ext_hook):
+            raise TypeError("`ext_hook` is not callable")
+
+    def feed(self, next_bytes):
+        assert self._feeding
+        view = _get_data_from_buffer(next_bytes)
+        if (len(self._buffer) - self._buff_i + len(view) > self._max_buffer_size):
+            raise BufferFull
+
+        # Strip buffer before checkpoint before reading file.
+        if self._buf_checkpoint > 0:
+            del self._buffer[:self._buf_checkpoint]
+            self._buff_i -= self._buf_checkpoint
+            self._buf_checkpoint = 0
+
+        # Use extend here: INPLACE_ADD += doesn't reliably typecast memoryview in jython
+        self._buffer.extend(view)
+
+    def _consume(self):
+        """ Gets rid of the used parts of the buffer. """
+        self._stream_offset += self._buff_i - self._buf_checkpoint
+        self._buf_checkpoint = self._buff_i
+
+    def _got_extradata(self):
+        return self._buff_i < len(self._buffer)
+
+    def _get_extradata(self):
+        return self._buffer[self._buff_i:]
+
+    def read_bytes(self, n):
+        return self._read(n)
+
+    def _read(self, n):
+        # (int) -> bytearray
+        self._reserve(n)
+        i = self._buff_i
+        self._buff_i = i+n
+        return self._buffer[i:i+n]
+
+    def _reserve(self, n):
+        remain_bytes = len(self._buffer) - self._buff_i - n
+
+        # Fast path: buffer has n bytes already
+        if remain_bytes >= 0:
+            return
+
+        if self._feeding:
+            self._buff_i = self._buf_checkpoint
+            raise OutOfData
+
+        # Strip buffer before checkpoint before reading file.
+        if self._buf_checkpoint > 0:
+            del self._buffer[:self._buf_checkpoint]
+            self._buff_i -= self._buf_checkpoint
+            self._buf_checkpoint = 0
+
+        # Read from file
+        remain_bytes = -remain_bytes
+        while remain_bytes > 0:
+            to_read_bytes = max(self._read_size, remain_bytes)
+            read_data = self.file_like.read(to_read_bytes)
+            if not read_data:
+                break
+            assert isinstance(read_data, bytes)
+            self._buffer += read_data
+            remain_bytes -= len(read_data)
+
+        if len(self._buffer) < n + self._buff_i:
+            self._buff_i = 0  # rollback
+            raise OutOfData
+
+    def _read_header(self, execute=EX_CONSTRUCT):
+        typ = TYPE_IMMEDIATE
+        n = 0
+        obj = None
+        self._reserve(1)
+        b = self._buffer[self._buff_i]
+        self._buff_i += 1
+        if b & 0b10000000 == 0:
+            obj = b
+        elif b & 0b11100000 == 0b11100000:
+            obj = -1 - (b ^ 0xff)
+        elif b & 0b11100000 == 0b10100000:
+            n = b & 0b00011111
+            typ = TYPE_RAW
+            if n > self._max_str_len:
+                raise ValueError("%s exceeds max_str_len(%s)", n, self._max_str_len)
+            obj = self._read(n)
+        elif b & 0b11110000 == 0b10010000:
+            n = b & 0b00001111
+            typ = TYPE_ARRAY
+            if n > self._max_array_len:
+                raise ValueError("%s exceeds max_array_len(%s)", n, self._max_array_len)
+        elif b & 0b11110000 == 0b10000000:
+            n = b & 0b00001111
+            typ = TYPE_MAP
+            if n > self._max_map_len:
+                raise ValueError("%s exceeds max_map_len(%s)", n, self._max_map_len)
+        elif b == 0xc0:
+            obj = None
+        elif b == 0xc2:
+            obj = False
+        elif b == 0xc3:
+            obj = True
+        elif b == 0xc4:
+            typ = TYPE_BIN
+            self._reserve(1)
+            n = self._buffer[self._buff_i]
+            self._buff_i += 1
+            if n > self._max_bin_len:
+                raise ValueError("%s exceeds max_bin_len(%s)" % (n, self._max_bin_len))
+            obj = self._read(n)
+        elif b == 0xc5:
+            typ = TYPE_BIN
+            self._reserve(2)
+            n = _unpack_from(">H", self._buffer, self._buff_i)[0]
+            self._buff_i += 2
+            if n > self._max_bin_len:
+                raise ValueError("%s exceeds max_bin_len(%s)" % (n, self._max_bin_len))
+            obj = self._read(n)
+        elif b == 0xc6:
+            typ = TYPE_BIN
+            self._reserve(4)
+            n = _unpack_from(">I", self._buffer, self._buff_i)[0]
+            self._buff_i += 4
+            if n > self._max_bin_len:
+                raise ValueError("%s exceeds max_bin_len(%s)" % (n, self._max_bin_len))
+            obj = self._read(n)
+        elif b == 0xc7:  # ext 8
+            typ = TYPE_EXT
+            self._reserve(2)
+            L, n = _unpack_from('Bb', self._buffer, self._buff_i)
+            self._buff_i += 2
+            if L > self._max_ext_len:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (L, self._max_ext_len))
+            obj = self._read(L)
+        elif b == 0xc8:  # ext 16
+            typ = TYPE_EXT
+            self._reserve(3)
+            L, n = _unpack_from('>Hb', self._buffer, self._buff_i)
+            self._buff_i += 3
+            if L > self._max_ext_len:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (L, self._max_ext_len))
+            obj = self._read(L)
+        elif b == 0xc9:  # ext 32
+            typ = TYPE_EXT
+            self._reserve(5)
+            L, n = _unpack_from('>Ib', self._buffer, self._buff_i)
+            self._buff_i += 5
+            if L > self._max_ext_len:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (L, self._max_ext_len))
+            obj = self._read(L)
+        elif b == 0xca:
+            self._reserve(4)
+            obj = _unpack_from(">f", self._buffer, self._buff_i)[0]
+            self._buff_i += 4
+        elif b == 0xcb:
+            self._reserve(8)
+            obj = _unpack_from(">d", self._buffer, self._buff_i)[0]
+            self._buff_i += 8
+        elif b == 0xcc:
+            self._reserve(1)
+            obj = self._buffer[self._buff_i]
+            self._buff_i += 1
+        elif b == 0xcd:
+            self._reserve(2)
+            obj = _unpack_from(">H", self._buffer, self._buff_i)[0]
+            self._buff_i += 2
+        elif b == 0xce:
+            self._reserve(4)
+            obj = _unpack_from(">I", self._buffer, self._buff_i)[0]
+            self._buff_i += 4
+        elif b == 0xcf:
+            self._reserve(8)
+            obj = _unpack_from(">Q", self._buffer, self._buff_i)[0]
+            self._buff_i += 8
+        elif b == 0xd0:
+            self._reserve(1)
+            obj = _unpack_from("b", self._buffer, self._buff_i)[0]
+            self._buff_i += 1
+        elif b == 0xd1:
+            self._reserve(2)
+            obj = _unpack_from(">h", self._buffer, self._buff_i)[0]
+            self._buff_i += 2
+        elif b == 0xd2:
+            self._reserve(4)
+            obj = _unpack_from(">i", self._buffer, self._buff_i)[0]
+            self._buff_i += 4
+        elif b == 0xd3:
+            self._reserve(8)
+            obj = _unpack_from(">q", self._buffer, self._buff_i)[0]
+            self._buff_i += 8
+        elif b == 0xd4:  # fixext 1
+            typ = TYPE_EXT
+            if self._max_ext_len < 1:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (1, self._max_ext_len))
+            self._reserve(2)
+            n, obj = _unpack_from("b1s", self._buffer, self._buff_i)
+            self._buff_i += 2
+        elif b == 0xd5:  # fixext 2
+            typ = TYPE_EXT
+            if self._max_ext_len < 2:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (2, self._max_ext_len))
+            self._reserve(3)
+            n, obj = _unpack_from("b2s", self._buffer, self._buff_i)
+            self._buff_i += 3
+        elif b == 0xd6:  # fixext 4
+            typ = TYPE_EXT
+            if self._max_ext_len < 4:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (4, self._max_ext_len))
+            self._reserve(5)
+            n, obj = _unpack_from("b4s", self._buffer, self._buff_i)
+            self._buff_i += 5
+        elif b == 0xd7:  # fixext 8
+            typ = TYPE_EXT
+            if self._max_ext_len < 8:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (8, self._max_ext_len))
+            self._reserve(9)
+            n, obj = _unpack_from("b8s", self._buffer, self._buff_i)
+            self._buff_i += 9
+        elif b == 0xd8:  # fixext 16
+            typ = TYPE_EXT
+            if self._max_ext_len < 16:
+                raise ValueError("%s exceeds max_ext_len(%s)" % (16, self._max_ext_len))
+            self._reserve(17)
+            n, obj = _unpack_from("b16s", self._buffer, self._buff_i)
+            self._buff_i += 17
+        elif b == 0xd9:
+            typ = TYPE_RAW
+            self._reserve(1)
+            n = self._buffer[self._buff_i]
+            self._buff_i += 1
+            if n > self._max_str_len:
+                raise ValueError("%s exceeds max_str_len(%s)", n, self._max_str_len)
+            obj = self._read(n)
+        elif b == 0xda:
+            typ = TYPE_RAW
+            self._reserve(2)
+            n, = _unpack_from(">H", self._buffer, self._buff_i)
+            self._buff_i += 2
+            if n > self._max_str_len:
+                raise ValueError("%s exceeds max_str_len(%s)", n, self._max_str_len)
+            obj = self._read(n)
+        elif b == 0xdb:
+            typ = TYPE_RAW
+            self._reserve(4)
+            n, = _unpack_from(">I", self._buffer, self._buff_i)
+            self._buff_i += 4
+            if n > self._max_str_len:
+                raise ValueError("%s exceeds max_str_len(%s)", n, self._max_str_len)
+            obj = self._read(n)
+        elif b == 0xdc:
+            typ = TYPE_ARRAY
+            self._reserve(2)
+            n, = _unpack_from(">H", self._buffer, self._buff_i)
+            self._buff_i += 2
+            if n > self._max_array_len:
+                raise ValueError("%s exceeds max_array_len(%s)", n, self._max_array_len)
+        elif b == 0xdd:
+            typ = TYPE_ARRAY
+            self._reserve(4)
+            n, = _unpack_from(">I", self._buffer, self._buff_i)
+            self._buff_i += 4
+            if n > self._max_array_len:
+                raise ValueError("%s exceeds max_array_len(%s)", n, self._max_array_len)
+        elif b == 0xde:
+            self._reserve(2)
+            n, = _unpack_from(">H", self._buffer, self._buff_i)
+            self._buff_i += 2
+            if n > self._max_map_len:
+                raise ValueError("%s exceeds max_map_len(%s)", n, self._max_map_len)
+            typ = TYPE_MAP
+        elif b == 0xdf:
+            self._reserve(4)
+            n, = _unpack_from(">I", self._buffer, self._buff_i)
+            self._buff_i += 4
+            if n > self._max_map_len:
+                raise ValueError("%s exceeds max_map_len(%s)", n, self._max_map_len)
+            typ = TYPE_MAP
+        else:
+            raise FormatError("Unknown header: 0x%x" % b)
+        return typ, n, obj
+
+    def _unpack(self, execute=EX_CONSTRUCT):
+        typ, n, obj = self._read_header(execute)
+
+        if execute == EX_READ_ARRAY_HEADER:
+            if typ != TYPE_ARRAY:
+                raise ValueError("Expected array")
+            return n
+        if execute == EX_READ_MAP_HEADER:
+            if typ != TYPE_MAP:
+                raise ValueError("Expected map")
+            return n
+        # TODO should we eliminate the recursion?
+        if typ == TYPE_ARRAY:
+            if execute == EX_SKIP:
+                for i in xrange(n):
+                    # TODO check whether we need to call `list_hook`
+                    self._unpack(EX_SKIP)
+                return
+            ret = newlist_hint(n)
+            for i in xrange(n):
+                ret.append(self._unpack(EX_CONSTRUCT))
+            if self._list_hook is not None:
+                ret = self._list_hook(ret)
+            # TODO is the interaction between `list_hook` and `use_list` ok?
+            return ret if self._use_list else tuple(ret)
+        if typ == TYPE_MAP:
+            if execute == EX_SKIP:
+                for i in xrange(n):
+                    # TODO check whether we need to call hooks
+                    self._unpack(EX_SKIP)
+                    self._unpack(EX_SKIP)
+                return
+            if self._object_pairs_hook is not None:
+                ret = self._object_pairs_hook(
+                    (self._unpack(EX_CONSTRUCT),
+                     self._unpack(EX_CONSTRUCT))
+                    for _ in xrange(n))
+            else:
+                ret = {}
+                for _ in xrange(n):
+                    key = self._unpack(EX_CONSTRUCT)
+                    if self._strict_map_key and type(key) not in (unicode, bytes):
+                        raise ValueError("%s is not allowed for map key" % str(type(key)))
+                    ret[key] = self._unpack(EX_CONSTRUCT)
+                if self._object_hook is not None:
+                    ret = self._object_hook(ret)
+            return ret
+        if execute == EX_SKIP:
+            return
+        if typ == TYPE_RAW:
+            if self._encoding is not None:
+                obj = obj.decode(self._encoding, self._unicode_errors)
+            elif self._raw:
+                obj = bytes(obj)
+            else:
+                obj = obj.decode('utf_8')
+            return obj
+        if typ == TYPE_EXT:
+            return self._ext_hook(n, bytes(obj))
+        if typ == TYPE_BIN:
+            return bytes(obj)
+        assert typ == TYPE_IMMEDIATE
+        return obj
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        try:
+            ret = self._unpack(EX_CONSTRUCT)
+            self._consume()
+            return ret
+        except OutOfData:
+            self._consume()
+            raise StopIteration
+        except RecursionError:
+            raise StackError
+
+    next = __next__
+
+    def skip(self):
+        self._unpack(EX_SKIP)
+        self._consume()
+
+    def unpack(self):
+        try:
+            ret = self._unpack(EX_CONSTRUCT)
+        except RecursionError:
+            raise StackError
+        self._consume()
+        return ret
+
+    def read_array_header(self):
+        ret = self._unpack(EX_READ_ARRAY_HEADER)
+        self._consume()
+        return ret
+
+    def read_map_header(self):
+        ret = self._unpack(EX_READ_MAP_HEADER)
+        self._consume()
+        return ret
+
+    def tell(self):
+        return self._stream_offset
+
+
+class Packer(object):
+    """
+    MessagePack Packer
+
+    usage:
+
+        packer = Packer()
+        astream.write(packer.pack(a))
+        astream.write(packer.pack(b))
+
+    Packer's constructor has some keyword arguments:
+
+    :param callable default:
+        Convert user type to builtin type that Packer supports.
+        See also simplejson's document.
+
+    :param bool use_single_float:
+        Use single precision float type for float. (default: False)
+
+    :param bool autoreset:
+        Reset buffer after each pack and return its content as `bytes`. (default: True).
+        If set this to false, use `bytes()` to get content and `.reset()` to clear buffer.
+
+    :param bool use_bin_type:
+        Use bin type introduced in msgpack spec 2.0 for bytes.
+        It also enables str8 type for unicode.
+
+    :param bool strict_types:
+        If set to true, types will be checked to be exact. Derived classes
+        from serializeable types will not be serialized and will be
+        treated as unsupported type and forwarded to default.
+        Additionally tuples will not be serialized as lists.
+        This is useful when trying to implement accurate serialization
+        for python types.
+
+    :param str encoding:
+        (deprecated) Convert unicode to bytes with this encoding. (default: 'utf-8')
+
+    :param str unicode_errors:
+        Error handler for encoding unicode. (default: 'strict')
+    """
+    def __init__(self, default=None, encoding=None, unicode_errors=None,
+                 use_single_float=False, autoreset=True, use_bin_type=False,
+                 strict_types=False):
+        if encoding is None:
+            encoding = 'utf_8'
+        else:
+            warnings.warn(
+                "encoding is deprecated, Use raw=False instead.",
+                DeprecationWarning, stacklevel=2)
+
+        if unicode_errors is None:
+            unicode_errors = 'strict'
+
+        self._strict_types = strict_types
+        self._use_float = use_single_float
+        self._autoreset = autoreset
+        self._use_bin_type = use_bin_type
+        self._encoding = encoding
+        self._unicode_errors = unicode_errors
+        self._buffer = StringIO()
+        if default is not None:
+            if not callable(default):
+                raise TypeError("default must be callable")
+        self._default = default
+
+    def _pack(self, obj, nest_limit=DEFAULT_RECURSE_LIMIT,
+              check=isinstance, check_type_strict=_check_type_strict):
+        default_used = False
+        if self._strict_types:
+            check = check_type_strict
+            list_types = list
+        else:
+            list_types = (list, tuple)
+        while True:
+            if nest_limit < 0:
+                raise ValueError("recursion limit exceeded")
+            if obj is None:
+                return self._buffer.write(b"\xc0")
+            if check(obj, bool):
+                if obj:
+                    return self._buffer.write(b"\xc3")
+                return self._buffer.write(b"\xc2")
+            if check(obj, int_types):
+                if 0 <= obj < 0x80:
+                    return self._buffer.write(struct.pack("B", obj))
+                if -0x20 <= obj < 0:
+                    return self._buffer.write(struct.pack("b", obj))
+                if 0x80 <= obj <= 0xff:
+                    return self._buffer.write(struct.pack("BB", 0xcc, obj))
+                if -0x80 <= obj < 0:
+                    return self._buffer.write(struct.pack(">Bb", 0xd0, obj))
+                if 0xff < obj <= 0xffff:
+                    return self._buffer.write(struct.pack(">BH", 0xcd, obj))
+                if -0x8000 <= obj < -0x80:
+                    return self._buffer.write(struct.pack(">Bh", 0xd1, obj))
+                if 0xffff < obj <= 0xffffffff:
+                    return self._buffer.write(struct.pack(">BI", 0xce, obj))
+                if -0x80000000 <= obj < -0x8000:
+                    return self._buffer.write(struct.pack(">Bi", 0xd2, obj))
+                if 0xffffffff < obj <= 0xffffffffffffffff:
+                    return self._buffer.write(struct.pack(">BQ", 0xcf, obj))
+                if -0x8000000000000000 <= obj < -0x80000000:
+                    return self._buffer.write(struct.pack(">Bq", 0xd3, obj))
+                if not default_used and self._default is not None:
+                    obj = self._default(obj)
+                    default_used = True
+                    continue
+                raise OverflowError("Integer value out of range")
+            if check(obj, (bytes, bytearray)):
+                n = len(obj)
+                if n >= 2**32:
+                    raise ValueError("%s is too large" % type(obj).__name__)
+                self._pack_bin_header(n)
+                return self._buffer.write(obj)
+            if check(obj, unicode):
+                if self._encoding is None:
+                    raise TypeError(
+                        "Can't encode unicode string: "
+                        "no encoding is specified")
+                obj = obj.encode(self._encoding, self._unicode_errors)
+                n = len(obj)
+                if n >= 2**32:
+                    raise ValueError("String is too large")
+                self._pack_raw_header(n)
+                return self._buffer.write(obj)
+            if check(obj, memoryview):
+                n = len(obj) * obj.itemsize
+                if n >= 2**32:
+                    raise ValueError("Memoryview is too large")
+                self._pack_bin_header(n)
+                return self._buffer.write(obj)
+            if check(obj, float):
+                if self._use_float:
+                    return self._buffer.write(struct.pack(">Bf", 0xca, obj))
+                return self._buffer.write(struct.pack(">Bd", 0xcb, obj))
+            if check(obj, ExtType):
+                code = obj.code
+                data = obj.data
+                assert isinstance(code, int)
+                assert isinstance(data, bytes)
+                L = len(data)
+                if L == 1:
+                    self._buffer.write(b'\xd4')
+                elif L == 2:
+                    self._buffer.write(b'\xd5')
+                elif L == 4:
+                    self._buffer.write(b'\xd6')
+                elif L == 8:
+                    self._buffer.write(b'\xd7')
+                elif L == 16:
+                    self._buffer.write(b'\xd8')
+                elif L <= 0xff:
+                    self._buffer.write(struct.pack(">BB", 0xc7, L))
+                elif L <= 0xffff:
+                    self._buffer.write(struct.pack(">BH", 0xc8, L))
+                else:
+                    self._buffer.write(struct.pack(">BI", 0xc9, L))
+                self._buffer.write(struct.pack("b", code))
+                self._buffer.write(data)
+                return
+            if check(obj, list_types):
+                n = len(obj)
+                self._pack_array_header(n)
+                for i in xrange(n):
+                    self._pack(obj[i], nest_limit - 1)
+                return
+            if check(obj, dict):
+                return self._pack_map_pairs(len(obj), dict_iteritems(obj),
+                                               nest_limit - 1)
+            if not default_used and self._default is not None:
+                obj = self._default(obj)
+                default_used = 1
+                continue
+            raise TypeError("Cannot serialize %r" % (obj, ))
+
+    def pack(self, obj):
+        try:
+            self._pack(obj)
+        except:
+            self._buffer = StringIO()  # force reset
+            raise
+        if self._autoreset:
+            ret = self._buffer.getvalue()
+            self._buffer = StringIO()
+            return ret
+
+    def pack_map_pairs(self, pairs):
+        self._pack_map_pairs(len(pairs), pairs)
+        if self._autoreset:
+            ret = self._buffer.getvalue()
+            self._buffer = StringIO()
+            return ret
+
+    def pack_array_header(self, n):
+        if n >= 2**32:
+            raise ValueError
+        self._pack_array_header(n)
+        if self._autoreset:
+            ret = self._buffer.getvalue()
+            self._buffer = StringIO()
+            return ret
+
+    def pack_map_header(self, n):
+        if n >= 2**32:
+            raise ValueError
+        self._pack_map_header(n)
+        if self._autoreset:
+            ret = self._buffer.getvalue()
+            self._buffer = StringIO()
+            return ret
+
+    def pack_ext_type(self, typecode, data):
+        if not isinstance(typecode, int):
+            raise TypeError("typecode must have int type.")
+        if not 0 <= typecode <= 127:
+            raise ValueError("typecode should be 0-127")
+        if not isinstance(data, bytes):
+            raise TypeError("data must have bytes type")
+        L = len(data)
+        if L > 0xffffffff:
+            raise ValueError("Too large data")
+        if L == 1:
+            self._buffer.write(b'\xd4')
+        elif L == 2:
+            self._buffer.write(b'\xd5')
+        elif L == 4:
+            self._buffer.write(b'\xd6')
+        elif L == 8:
+            self._buffer.write(b'\xd7')
+        elif L == 16:
+            self._buffer.write(b'\xd8')
+        elif L <= 0xff:
+            self._buffer.write(b'\xc7' + struct.pack('B', L))
+        elif L <= 0xffff:
+            self._buffer.write(b'\xc8' + struct.pack('>H', L))
+        else:
+            self._buffer.write(b'\xc9' + struct.pack('>I', L))
+        self._buffer.write(struct.pack('B', typecode))
+        self._buffer.write(data)
+
+    def _pack_array_header(self, n):
+        if n <= 0x0f:
+            return self._buffer.write(struct.pack('B', 0x90 + n))
+        if n <= 0xffff:
+            return self._buffer.write(struct.pack(">BH", 0xdc, n))
+        if n <= 0xffffffff:
+            return self._buffer.write(struct.pack(">BI", 0xdd, n))
+        raise ValueError("Array is too large")
+
+    def _pack_map_header(self, n):
+        if n <= 0x0f:
+            return self._buffer.write(struct.pack('B', 0x80 + n))
+        if n <= 0xffff:
+            return self._buffer.write(struct.pack(">BH", 0xde, n))
+        if n <= 0xffffffff:
+            return self._buffer.write(struct.pack(">BI", 0xdf, n))
+        raise ValueError("Dict is too large")
+
+    def _pack_map_pairs(self, n, pairs, nest_limit=DEFAULT_RECURSE_LIMIT):
+        self._pack_map_header(n)
+        for (k, v) in pairs:
+            self._pack(k, nest_limit - 1)
+            self._pack(v, nest_limit - 1)
+
+    def _pack_raw_header(self, n):
+        if n <= 0x1f:
+            self._buffer.write(struct.pack('B', 0xa0 + n))
+        elif self._use_bin_type and n <= 0xff:
+            self._buffer.write(struct.pack('>BB', 0xd9, n))
+        elif n <= 0xffff:
+            self._buffer.write(struct.pack(">BH", 0xda, n))
+        elif n <= 0xffffffff:
+            self._buffer.write(struct.pack(">BI", 0xdb, n))
+        else:
+            raise ValueError('Raw is too large')
+
+    def _pack_bin_header(self, n):
+        if not self._use_bin_type:
+            return self._pack_raw_header(n)
+        elif n <= 0xff:
+            return self._buffer.write(struct.pack('>BB', 0xc4, n))
+        elif n <= 0xffff:
+            return self._buffer.write(struct.pack(">BH", 0xc5, n))
+        elif n <= 0xffffffff:
+            return self._buffer.write(struct.pack(">BI", 0xc6, n))
+        else:
+            raise ValueError('Bin is too large')
+
+    def bytes(self):
+        """Return internal buffer contents as bytes object"""
+        return self._buffer.getvalue()
+
+    def reset(self):
+        """Reset internal buffer.
+
+        This method is usaful only when autoreset=False.
+        """
+        self._buffer = StringIO()
+
+    def getbuffer(self):
+        """Return view of internal buffer."""
+        if USING_STRINGBUILDER or PY2:
+            return memoryview(self.bytes())
+        else:
+            return self._buffer.getbuffer()