# Source code for cherrypy._cpreqbody

    """Request body processing for CherryPy.

    .. versionadded:: 3.2

    Application authors have complete control over the parsing of HTTP request
    entities. In short,
    :attr:`cherrypy.request.body<cherrypy._cprequest.Request.body>`
    is now always set to an instance of
    :class:`RequestBody<cherrypy._cpreqbody.RequestBody>`,
    and *that* class is a subclass of :class:`Entity<cherrypy._cpreqbody.Entity>`.

    When an HTTP request includes an entity body, it is often desirable to
    provide that information to applications in a form other than the raw bytes.
    Different content types demand different approaches. Examples:

     * For a GIF file, we want the raw bytes in a stream.
     * An HTML form is better parsed into its component fields, and each text field
       decoded from bytes to unicode.
     * A JSON body should be deserialized into a Python dict or list.

    When the request contains a Content-Type header, the media type is used as a
    key to look up a value in the
    :attr:`request.body.processors<cherrypy._cpreqbody.Entity.processors>` dict.
    If the full media
    type is not found, then the major type is tried; for example, if no processor
    is found for the 'image/jpeg' type, then we look for a processor for the
    'image' types altogether. If neither the full type nor the major type has a
    matching processor, then a default processor is used
    (:func:`default_proc<cherrypy._cpreqbody.Entity.default_proc>`). For most
    types, this means no processing is done, and the body is left unread as a
    raw byte stream. Processors are configurable in an 'on_start_resource' hook.

    Some processors, especially those for the 'text' types, attempt to decode bytes
    to unicode. If the Content-Type request header includes a 'charset' parameter,
    this is used to decode the entity. Otherwise, one or more default charsets may
    be attempted, although this decision is up to each processor. If a processor
    successfully decodes an Entity or Part, it should set the
    :attr:`charset<cherrypy._cpreqbody.Entity.charset>` attribute
    on the Entity or Part to the name of the successful charset, so that
    applications can easily re-encode or transcode the value if they wish.

    If the Content-Type of the request entity is of major type 'multipart', then
    the above parsing process, and possibly a decoding process, is performed for
    each part.

    For both the full entity and multipart parts, a Content-Disposition header may
    be used to fill :attr:`name<cherrypy._cpreqbody.Entity.name>` and
    :attr:`filename<cherrypy._cpreqbody.Entity.filename>` attributes on the
    request.body or the Part.

    .. _custombodyprocessors:

    Custom Processors
    =================

    You can add your own processors for any specific or major MIME type. Simply add
    it to the :attr:`processors<cherrypy._cprequest.Entity.processors>` dict in a
    hook/tool that runs at ``on_start_resource`` or ``before_request_body``.
    Here's the built-in JSON tool for an example::

        def json_in(force=True, debug=False):
            request = cherrypy.serving.request
            def json_processor(entity):
                '''Read application/json data into request.json.'''
                if not entity.headers.get("Content-Length", ""):
                    raise cherrypy.HTTPError(411)

                body = entity.fp.read()
                try:
                    request.json = json_decode(body)
                except ValueError:
                    raise cherrypy.HTTPError(400, 'Invalid JSON document')
            if force:
                request.body.processors.clear()
                request.body.default_proc = cherrypy.HTTPError(
                    415, 'Expected an application/json content type')
            request.body.processors['application/json'] = json_processor

    We begin by defining a new ``json_processor`` function to stick in the
    ``processors`` dictionary. All processor functions take a single argument,
    the ``Entity`` instance they are to process. It will be called whenever a
    request is received (for those URI's where the tool is turned on) which
    has a ``Content-Type`` of "application/json".

    First, it checks for a valid ``Content-Length`` (raising 411 if not valid),
    then reads the remaining bytes on the socket. The ``fp`` object knows its
    own length, so it won't hang waiting for data that never arrives. It will
    return when all data has been read. Then, we decode those bytes using
    Python's built-in ``json`` module, and stick the decoded result onto
    ``request.json`` . If it cannot be decoded, we raise 400.

    If the "force" argument is True (the default), the ``Tool`` clears the
    ``processors`` dict so that request entities of other ``Content-Types``
    aren't parsed at all. Since there's no entry for those invalid MIME
    types, the ``default_proc`` method of ``cherrypy.request.body`` is
    called. But this does nothing by default (usually to provide the page
    handler an opportunity to handle it.)
    But in our case, we want to raise 415, so we replace
    ``request.body.default_proc``
    with the error (``HTTPError`` instances, when called, raise themselves).

    If we were defining a custom processor, we can do so without making a ``Tool``.
    Just add the config entry::

        request.body.processors = {'application/json': json_processor}

    Note that you can only replace the ``processors`` dict wholesale this way,
    not update the existing one.
    """

    try:
        from io import DEFAULT_BUFFER_SIZE
    except ImportError:
        DEFAULT_BUFFER_SIZE = 8192
    import re
    import sys
    import tempfile
    from urllib.parse import unquote

    import cheroot.server

    import cherrypy
    from cherrypy._cpcompat import ntou
    from cherrypy.lib import httputil

    def unquote_plus(bs):
        """Bytes version of urllib.parse.unquote_plus."""
        bs = bs.replace(b'+', b' ')
        atoms = bs.split(b'%')
        for i in range(1, len(atoms)):
            item = atoms[i]
            try:
                pct = int(item[:2], 16)
                atoms[i] = bytes([pct]) + item[2:]
            except ValueError:
                pass
        return b''.join(atoms)

    # ------------------------------- Processors -------------------------------- #

    def process_urlencoded(entity):
        """Read application/x-www-form-urlencoded data into entity.params."""
        qs = entity.fp.read()
        for charset in entity.attempt_charsets:
            try:
                params = {}
                for aparam in qs.split(b'&'):
                    for pair in aparam.split(b';'):
                        if not pair:
                            continue

                        atoms = pair.split(b'=', 1)
                        if len(atoms) == 1:
                            atoms.append(b'')

                        key = unquote_plus(atoms[0]).decode(charset)
                        value = unquote_plus(atoms[1]).decode(charset)

                        if key in params:
                            if not isinstance(params[key], list):
                                params[key] = [params[key]]
                            params[key].append(value)
                        else:
                            params[key] = value
            except UnicodeDecodeError:
                pass
            else:
                entity.charset = charset
                break
        else:
            raise cherrypy.HTTPError(
                400, 'The request entity could not be decoded. The following '
                'charsets were attempted: %s' % repr(entity.attempt_charsets))

        # Now that all values have been successfully parsed and decoded,
        # apply them to the entity.params dict.
        for key, value in params.items():
            if key in entity.params:
                if not isinstance(entity.params[key], list):
                    entity.params[key] = [entity.params[key]]
                entity.params[key].append(value)
            else:
                entity.params[key] = value

    def process_multipart(entity):
        """Read all multipart parts into entity.parts."""
        ib = ''
        if 'boundary' in entity.content_type.params:
            # http://tools.ietf.org/html/rfc2046#section-5.1.1
            # "The grammar for parameters on the Content-type field is such that it
            # is often necessary to enclose the boundary parameter values in quotes
            # on the Content-type line"
            ib = entity.content_type.params['boundary'].strip('"')

        if not re.match('^[ -~]{0,200}[!-~]$', ib):
            raise ValueError('Invalid boundary in multipart form: %r' % (ib,))

        ib = ('--' + ib).encode('ascii')

        # Find the first marker
        while True:
            b = entity.readline()
            if not b:
                return

            b = b.strip()
            if b == ib:
                break

        # Read all parts
        while True:
            part = entity.part_class.from_fp(entity.fp, ib)
            entity.parts.append(part)
            part.process()
            if part.fp.done:
                break

    def process_multipart_form_data(entity):
        """Read all multipart/form-data parts into entity.parts or entity.params.
        """
        process_multipart(entity)

        kept_parts = []
        for part in entity.parts:
            if part.name is None:
                kept_parts.append(part)
            else:
                if part.filename is None:
                    # It's a regular field
                    value = part.fullvalue()
                else:
                    # It's a file upload. Retain the whole part so consumer code
                    # has access to its .file and .filename attributes.
                    value = part

                if part.name in entity.params:
                    if not isinstance(entity.params[part.name], list):
                        entity.params[part.name] = [entity.params[part.name]]
                    entity.params[part.name].append(value)
                else:
                    entity.params[part.name] = value

        entity.parts = kept_parts

    def _old_process_multipart(entity):
        """The behavior of 3.2 and lower.

        Deprecated and will be changed in 3.3.
        """
        process_multipart(entity)

        params = entity.params

        for part in entity.parts:
            if part.name is None:
                key = ntou('parts')
            else:
                key = part.name

            if part.filename is None:
                # It's a regular field
                value = part.fullvalue()
            else:
                # It's a file upload. Retain the whole part so consumer code
                # has access to its .file and .filename attributes.
                value = part

            if key in params:
                if not isinstance(params[key], list):
                    params[key] = [params[key]]
                params[key].append(value)
            else:
                params[key] = value

    # -------------------------------- Entities --------------------------------- #

    class Entity(object):
        """An HTTP request body, or MIME multipart body.

        This class collects information about the HTTP request entity. When a
        given entity is of MIME type "multipart", each part is parsed into its own
        Entity instance, and the set of parts stored in
        :attr:`entity.parts<cherrypy._cpreqbody.Entity.parts>`.

        Between the ``before_request_body`` and ``before_handler`` tools, CherryPy
        tries to process the request body (if any) by calling
        :func:`request.body.process<cherrypy._cpreqbody.RequestBody.process>`.
        This uses the ``content_type`` of the Entity to look up a suitable
        processor in
        :attr:`Entity.processors<cherrypy._cpreqbody.Entity.processors>`,
        a dict.
        If a matching processor cannot be found for the complete Content-Type,
        it tries again using the major type. For example, if a request with an
        entity of type "image/jpeg" arrives, but no processor can be found for
        that complete type, then one is sought for the major type "image". If a
        processor is still not found, then the
        :func:`default_proc<cherrypy._cpreqbody.Entity.default_proc>` method
        of the Entity is called (which does nothing by default; you can
        override this too).

        CherryPy includes processors for the "application/x-www-form-urlencoded"
        type, the "multipart/form-data" type, and the "multipart" major type.
        CherryPy 3.2 processes these types almost exactly as older versions.
        Parts are passed as arguments to the page handler using their
        ``Content-Disposition.name`` if given, otherwise in a generic "parts"
        argument. Each such part is either a string, or the
        :class:`Part<cherrypy._cpreqbody.Part>` itself if it's a file. (In this
        case it will have ``file`` and ``filename`` attributes, or possibly a
        ``value`` attribute). Each Part is itself a subclass of
        Entity, and has its own ``process`` method and ``processors`` dict.

        There is a separate processor for the "multipart" major type which is more
        flexible, and simply stores all multipart parts in
        :attr:`request.body.parts<cherrypy._cpreqbody.Entity.parts>`. You can
        enable it with::

            cherrypy.request.body.processors['multipart'] = \
                _cpreqbody.process_multipart

        in an ``on_start_resource`` tool.
        """

        # http://tools.ietf.org/html/rfc2046#section-4.1.2:
        # "The default character set, which must be assumed in the
        # absence of a charset parameter, is US-ASCII."
        # However, many browsers send data in utf-8 with no charset.
        attempt_charsets = ['utf-8']
        r"""A list of strings, each of which should be a known encoding.

        When the Content-Type of the request body warrants it, each of the given
        encodings will be tried in order. The first one to successfully decode the
        entity without raising an error is stored as
        :attr:`entity.charset<cherrypy._cpreqbody.Entity.charset>`. This defaults
        to ``['utf-8']`` (plus 'ISO-8859-1' for "text/\*" types, as required by
        `HTTP/1.1
        <http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1>`_),
        but ``['us-ascii', 'utf-8']`` for multipart parts.
        """

        charset = None
        """The successful decoding; see "attempt_charsets" above."""

        content_type = None
        """The value of the Content-Type request header.

        If the Entity is part of a multipart payload, this will be the
        Content-Type given in the MIME headers for this part.
        """

        default_content_type = 'application/x-www-form-urlencoded'
        """This defines a default ``Content-Type`` to use if no Content-Type header
        is given.

        The empty string is used for RequestBody, which results in the
        request body not being read or parsed at all. This is by design; a missing
        ``Content-Type`` header in the HTTP request entity is an error at best,
        and a security hole at worst. For multipart parts, however, the MIME spec
        declares that a part with no Content-Type defaults to "text/plain"
        (see :class:`Part<cherrypy._cpreqbody.Part>`).
        """

        filename = None
        """The ``Content-Disposition.filename`` header, if available."""

        fp = None
        """The readable socket file object."""

        headers = None
        """A dict of request/multipart header names and values.

        This is a copy of the ``request.headers`` for the ``request.body``;
        for multipart parts, it is the set of headers for that part.
        """

        length = None
        """The value of the ``Content-Length`` header, if provided."""

        name = None
        """The "name" parameter of the ``Content-Disposition`` header, if any."""

        params = None
        """
        If the request Content-Type is 'application/x-www-form-urlencoded' or
        multipart, this will be a dict of the params pulled from the entity
        body; that is, it will be the portion of request.params that come
        from the message body (sometimes called "POST params", although they
        can be sent with various HTTP method verbs). This value is set between
        the 'before_request_body' and 'before_handler' hooks (assuming that
        process_request_body is True)."""

        processors = {'application/x-www-form-urlencoded': process_urlencoded,
                      'multipart/form-data': process_multipart_form_data,
                      'multipart': process_multipart,
                      }
        """A dict of Content-Type names to processor methods."""

        parts = None
        """A list of Part instances if ``Content-Type`` is of major type
        "multipart"."""

        part_class = None
        """The class used for multipart parts.

        You can replace this with custom subclasses to alter the processing
        of multipart parts.
        """

        def __init__(self, fp, headers, params=None, parts=None):
            # Make an instance-specific copy of the class processors
            # so Tools, etc. can replace them per-request.
            self.processors = self.processors.copy()

            self.fp = fp
            self.headers = headers

            if params is None:
                params = {}
            self.params = params

            if parts is None:
                parts = []
            self.parts = parts

            # Content-Type
            self.content_type = headers.elements('Content-Type')
            if self.content_type:
                self.content_type = self.content_type[0]
            else:
                self.content_type = httputil.HeaderElement.from_str(
                    self.default_content_type)

            # Copy the class 'attempt_charsets', prepending any Content-Type
            # charset
            dec = self.content_type.params.get('charset', None)
            if dec:
                self.attempt_charsets = [dec] + [c for c in self.attempt_charsets
                                                 if c != dec]
            else:
                self.attempt_charsets = self.attempt_charsets[:]

            # Length
            self.length = None
            clen = headers.get('Content-Length', None)
            # If Transfer-Encoding is 'chunked', ignore any Content-Length.
            if (
                clen is not None and
                'chunked' not in headers.get('Transfer-Encoding', '')
            ):
                try:
                    self.length = int(clen)
                except ValueError:
                    pass

            # Content-Disposition
            self.name = None
            self.filename = None
            disp = headers.elements('Content-Disposition')
            if disp:
                disp = disp[0]
                if 'name' in disp.params:
                    self.name = disp.params['name']
                    if self.name.startswith('"') and self.name.endswith('"'):
                        self.name = self.name[1:-1]
                if 'filename' in disp.params:
                    self.filename = disp.params['filename']
                    if (
                        self.filename.startswith('"') and
                        self.filename.endswith('"')
                    ):
                        self.filename = self.filename[1:-1]
                if 'filename*' in disp.params:
                    # @see https://tools.ietf.org/html/rfc5987
                    encoding, lang, filename = disp.params['filename*'].split("'")
                    self.filename = unquote(str(filename), encoding)

        def read(self, size=None, fp_out=None):
            return self.fp.read(size, fp_out)

        def readline(self, size=None):
            return self.fp.readline(size)

        def readlines(self, sizehint=None):
            return self.fp.readlines(sizehint)

        def __iter__(self):
            return self

        def __next__(self):
            line = self.readline()
            if not line:
                raise StopIteration
            return line

        def next(self):
            return self.__next__()

        def read_into_file(self, fp_out=None):
            """Read the request body into fp_out (or make_file() if None).

            Return fp_out.
            """
            if fp_out is None:
                fp_out = self.make_file()
            self.read(fp_out=fp_out)
            return fp_out

        def make_file(self):
            """Return a file-like object into which the request body will be read.

            By default, this will return a TemporaryFile. Override as needed.
            See also :attr:`cherrypy._cpreqbody.Part.maxrambytes`.
            """
            return tempfile.TemporaryFile()

        def fullvalue(self):
            """Return this entity as a string, whether stored in a file or not."""
            if self.file:
                # It was stored in a tempfile. Read it.
                self.file.seek(0)
                value = self.file.read()
                self.file.seek(0)
            else:
                value = self.value
            value = self.decode_entity(value)
            return value

        def decode_entity(self, value):
            """Return a given byte encoded value as a string."""
            for charset in self.attempt_charsets:
                try:
                    value = value.decode(charset)
                except UnicodeDecodeError:
                    pass
                else:
                    self.charset = charset
                    return value
            else:
                raise cherrypy.HTTPError(
                    400,
                    'The request entity could not be decoded. The following '
                    'charsets were attempted: %s' % repr(self.attempt_charsets)
                )

        def process(self):
            """Execute the best-match processor for the given media type."""
            proc = None
            ct = self.content_type.value
            try:
                proc = self.processors[ct]
            except KeyError:
                toptype = ct.split('/', 1)[0]
                try:
                    proc = self.processors[toptype]
                except KeyError:
                    pass
            if proc is None:
                self.default_proc()
            else:
                proc(self)

        def default_proc(self):
            """Called if a more-specific processor is not found for the
            ``Content-Type``.
            """
            # Leave the fp alone for someone else to read. This works fine
            # for request.body, but the Part subclasses need to override this
            # so they can move on to the next part.
            pass

    class Part(Entity):
        """A MIME part entity, part of a multipart entity."""

        # "The default character set, which must be assumed in the absence of a
        # charset parameter, is US-ASCII."
        attempt_charsets = ['us-ascii', 'utf-8']
        r"""A list of strings, each of which should be a known encoding.

        When the Content-Type of the request body warrants it, each of the given
        encodings will be tried in order. The first one to successfully decode the
        entity without raising an error is stored as
        :attr:`entity.charset<cherrypy._cpreqbody.Entity.charset>`. This defaults
        to ``['utf-8']`` (plus 'ISO-8859-1' for "text/\*" types, as required by
        `HTTP/1.1
        <http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1>`_),
        but ``['us-ascii', 'utf-8']`` for multipart parts.
        """

        boundary = None
        """The MIME multipart boundary."""

        default_content_type = 'text/plain'
        """This defines a default ``Content-Type`` to use if no Content-Type header
        is given. The empty string is used for RequestBody, which results in the
        request body not being read or parsed at all. This is by design; a missing
        ``Content-Type`` header in the HTTP request entity is an error at best,
        and a security hole at worst. For multipart parts, however (this class),
        the MIME spec declares that a part with no Content-Type defaults to
        "text/plain".
        """

        # This is the default in stdlib cgi. We may want to increase it.
        maxrambytes = 1000
        """The threshold of bytes after which point the ``Part`` will store
        its data in a file (generated by
        :func:`make_file<cherrypy._cprequest.Entity.make_file>`)
        instead of a string. Defaults to 1000, just like the :mod:`cgi`
        module in Python's standard library.
        """

        def __init__(self, fp, headers, boundary):
            Entity.__init__(self, fp, headers)
            self.boundary = boundary
            self.file = None
            self.value = None

        @classmethod
        def from_fp(cls, fp, boundary):
            headers = cls.read_headers(fp)
            return cls(fp, headers, boundary)

        @classmethod
        def read_headers(cls, fp):
            headers = httputil.HeaderMap()
            while True:
                line = fp.readline()
                if not line:
                    # No more data--illegal end of headers
                    raise EOFError('Illegal end of headers.')

                if line == b'\r\n':
                    # Normal end of headers
                    break
                if not line.endswith(b'\r\n'):
                    raise ValueError('MIME requires CRLF terminators: %r' % line)

                if line[0] in b' \t':
                    # It's a continuation line.
                    v = line.strip().decode('ISO-8859-1')
                else:
                    k, v = line.split(b':', 1)
                    k = k.strip().decode('ISO-8859-1')
                    v = v.strip().decode('ISO-8859-1')

                existing = headers.get(k)
                if existing:
                    v = ', '.join((existing, v))
                headers[k] = v

            return headers

        def read_lines_to_boundary(self, fp_out=None):
            """Read bytes from self.fp and return or write them to a file.

            If the 'fp_out' argument is None (the default), all bytes read
            are returned in a single byte string.

            If the 'fp_out' argument is not None, it must be a file-like
            object that supports the 'write' method; all bytes read will be
            written to the fp, and that fp is returned.
            """
            endmarker = self.boundary + b'--'
            delim = b''
            prev_lf = True
            lines = []
            seen = 0
            while True:
                line = self.fp.readline(1 << 16)
                if not line:
                    raise EOFError('Illegal end of multipart body.')
                if line.startswith(b'--') and prev_lf:
                    strippedline = line.strip()
                    if strippedline == self.boundary:
                        break
                    if strippedline == endmarker:
                        self.fp.finish()
                        break

                line = delim + line

                if line.endswith(b'\r\n'):
                    delim = b'\r\n'
                    line = line[:-2]
                    prev_lf = True
                elif line.endswith(b'\n'):
                    delim = b'\n'
                    line = line[:-1]
                    prev_lf = True
                else:
                    delim = b''
                    prev_lf = False

                if fp_out is None:
                    lines.append(line)
                    seen += len(line)
                    if seen > self.maxrambytes:
                        fp_out = self.make_file()
                        for line in lines:
                            fp_out.write(line)
                else:
                    fp_out.write(line)

            if fp_out is None:
                result = b''.join(lines)
                return result
            else:
                fp_out.seek(0)
                return fp_out

        def default_proc(self):
            """Called if a more-specific processor is not found for the
            ``Content-Type``.
            """
            if self.filename:
                # Always read into a file if a .filename was given.
                self.file = self.read_into_file()
            else:
                result = self.read_lines_to_boundary()
                if isinstance(result, bytes):
                    self.value = result
                else:
                    self.file = result

        def read_into_file(self, fp_out=None):
            """Read the request body into fp_out (or make_file() if None).

            Return fp_out.
            """
            if fp_out is None:
                fp_out = self.make_file()
            self.read_lines_to_boundary(fp_out=fp_out)
            return fp_out

    Entity.part_class = Part

    inf = float('inf')

    class SizedReader:

        def __init__(self, fp, length, maxbytes, bufsize=DEFAULT_BUFFER_SIZE,
                     has_trailers=False):
            # Wrap our fp in a buffer so peek() works
            self.fp = fp
            self.length = length
            self.maxbytes = maxbytes
            self.buffer = b''
            self.bufsize = bufsize
            self.bytes_read = 0
            self.done = False
            self.has_trailers = has_trailers

        def read(self, size=None, fp_out=None):
            """Read bytes from the request body and return or write them to a file.

            A number of bytes less than or equal to the 'size' argument are
            read off the socket. The actual number of bytes read are tracked
            in self.bytes_read. The number may be smaller than 'size' when
            1) the client sends fewer bytes, 2) the 'Content-Length' request
            header specifies fewer bytes than requested, or 3) the number of
            bytes read exceeds self.maxbytes (in which case, 413 is raised).

            If the 'fp_out' argument is None (the default), all bytes read
            are returned in a single byte string.

            If the 'fp_out' argument is not None, it must be a file-like
            object that supports the 'write' method; all bytes read will be
            written to the fp, and None is returned.
            """

            if self.length is None:
                if size is None:
                    remaining = inf
                else:
                    remaining = size
            else:
                remaining = self.length - self.bytes_read
                if size and size < remaining:
                    remaining = size
            if remaining == 0:
                self.finish()
                if fp_out is None:
                    return b''
                else:
                    return None

            chunks = []

            # Read bytes from the buffer.
            if self.buffer:
                if remaining is inf:
                    data = self.buffer
                    self.buffer = b''
                else:
                    data = self.buffer[:remaining]
                    self.buffer = self.buffer[remaining:]
                datalen = len(data)
                remaining -= datalen

                # Check lengths.
                self.bytes_read += datalen
                if self.maxbytes and self.bytes_read > self.maxbytes:
                    raise cherrypy.HTTPError(413)

                # Store the data.
                if fp_out is None:
                    chunks.append(data)
                else:
                    fp_out.write(data)

            # Read bytes from the socket.
            while remaining > 0:
                chunksize = min(remaining, self.bufsize)
                try:
                    data = self.fp.read(chunksize)
                except Exception:
                    e = sys.exc_info()[1]
                    if e.__class__.__name__ == 'MaxSizeExceeded':
                        # Post data is too big
                        raise cherrypy.HTTPError(
                            413, 'Maximum request length: %r' % e.args[1])
                    else:
                        raise
                if not data:
                    self.finish()
                    break
                datalen = len(data)
                remaining -= datalen

                # Check lengths.
                self.bytes_read += datalen
                if self.maxbytes and self.bytes_read > self.maxbytes:
                    raise cherrypy.HTTPError(413)

                # Store the data.
                if fp_out is None:
                    chunks.append(data)
                else:
                    fp_out.write(data)

            if fp_out is None:
                return b''.join(chunks)

        def readline(self, size=None):
            """Read a line from the request body and return it."""
            chunks = []
            while size is None or size > 0:
                chunksize = self.bufsize
                if size is not None and size < self.bufsize:
                    chunksize = size
                data = self.read(chunksize)
                if not data:
                    break
                pos = data.find(b'\n') + 1
                if pos:
                    chunks.append(data[:pos])
                    remainder = data[pos:]
                    self.buffer += remainder
                    self.bytes_read -= len(remainder)
                    break
                else:
                    chunks.append(data)
            return b''.join(chunks)

        def readlines(self, sizehint=None):
            """Read lines from the request body and return them."""
            if self.length is not None:
                if sizehint is None:
                    sizehint = self.length - self.bytes_read
                else:
                    sizehint = min(sizehint, self.length - self.bytes_read)

            lines = []
            seen = 0
            while True:
                line = self.readline()
                if not line:
                    break
                lines.append(line)
                seen += len(line)
                if seen >= sizehint:
                    break
            return lines

        def finish(self):
            self.done = True
            if self.has_trailers and hasattr(self.fp, 'read_trailer_lines'):
                self.trailers = {}

                try:
                    for line in self.fp.read_trailer_lines():
                        if line[0] in b' \t':
                            # It's a continuation line.
                            v = line.strip()
                        else:
                            try:
                                k, v = line.split(b':', 1)
                            except ValueError:
                                raise ValueError('Illegal header line.')
                            k = k.strip().title()
                            v = v.strip()

                        if k in cheroot.server.comma_separated_headers:
                            existing = self.trailers.get(k)
                            if existing:
                                v = b', '.join((existing, v))
                        self.trailers[k] = v
                except Exception:
                    e = sys.exc_info()[1]
                    if e.__class__.__name__ == 'MaxSizeExceeded':
                        # Post data is too big
                        raise cherrypy.HTTPError(
                            413, 'Maximum request length: %r' % e.args[1])
                    else:
                        raise

    class RequestBody(Entity):
        """The entity of the HTTP request."""

        bufsize = 8 * 1024
        """The buffer size used when reading the socket."""

        # Don't parse the request body at all if the client didn't provide
        # a Content-Type header. See
        # https://github.com/cherrypy/cherrypy/issues/790
        default_content_type = ''
        """This defines a default ``Content-Type`` to use if no Content-Type header
        is given. The empty string is used for RequestBody, which results in the
        request body not being read or parsed at all. This is by design; a missing
        ``Content-Type`` header in the HTTP request entity is an error at best,
        and a security hole at worst. For multipart parts, however, the MIME spec
        declares that a part with no Content-Type defaults to "text/plain"
        (see :class:`Part<cherrypy._cpreqbody.Part>`).
        """

        maxbytes = None
        """Raise ``MaxSizeExceeded`` if more bytes than this are read from
        the socket.
        """

        def __init__(self, fp, headers, params=None, request_params=None):
            Entity.__init__(self, fp, headers, params)

            # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1
            # When no explicit charset parameter is provided by the
            # sender, media subtypes of the "text" type are defined
            # to have a default charset value of "ISO-8859-1" when
            # received via HTTP.
            if self.content_type.value.startswith('text/'):
                for c in ('ISO-8859-1', 'iso-8859-1', 'Latin-1', 'latin-1'):
                    if c in self.attempt_charsets:
                        break
                else:
                    self.attempt_charsets.append('ISO-8859-1')

            # Temporary fix while deprecating passing .parts as .params.
            self.processors['multipart'] = _old_process_multipart

            if request_params is None:
                request_params = {}
            self.request_params = request_params

        def process(self):
            """Process the request entity based on its Content-Type."""
            # "The presence of a message-body in a request is signaled by the
            # inclusion of a Content-Length or Transfer-Encoding header field in
            # the request's message-headers."
            # It is possible to send a POST request with no body, for example;
            # however, app developers are responsible in that case to set
            # cherrypy.request.process_body to False so this method isn't called.
            h = cherrypy.serving.request.headers
            if 'Content-Length' not in h and 'Transfer-Encoding' not in h:
                raise cherrypy.HTTPError(411)

            self.fp = SizedReader(self.fp, self.length,
                                  self.maxbytes, bufsize=self.bufsize,
                                  has_trailers='Trailer' in h)
            super(RequestBody, self).process()

            # Body params should also be a part of the request_params
            # add them in here.
            request_params = self.request_params
            for key, value in self.params.items():
                if key in request_params:
                    if not isinstance(request_params[key], list):
                        request_params[key] = [request_params[key]]
                    request_params[key].append(value)
                else:
                    request_params[key] = value