662 lines
29 KiB
Python
662 lines
29 KiB
Python
###############################################################################
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#
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# The MIT License (MIT)
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#
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# Copyright (c) Crossbar.io Technologies GmbH
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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#
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###############################################################################
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import zlib
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from autobahn.util import public
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from autobahn.websocket.compress_base import PerMessageCompressOffer, \
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PerMessageCompressOfferAccept, \
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PerMessageCompressResponse, \
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PerMessageCompressResponseAccept, \
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PerMessageCompress
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__all__ = (
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'PerMessageDeflateMixin',
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'PerMessageDeflateOffer',
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'PerMessageDeflateOfferAccept',
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'PerMessageDeflateResponse',
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'PerMessageDeflateResponseAccept',
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'PerMessageDeflate',
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)
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class PerMessageDeflateMixin(object):
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"""
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Mixin class for this extension.
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"""
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EXTENSION_NAME = "permessage-deflate"
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"""
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Name of this WebSocket extension.
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"""
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WINDOW_SIZE_PERMISSIBLE_VALUES = [9, 10, 11, 12, 13, 14, 15]
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"""
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Permissible value for window size parameter.
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Higher values use more memory, but produce smaller output. The default is 15.
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"""
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MEM_LEVEL_PERMISSIBLE_VALUES = [1, 2, 3, 4, 5, 6, 7, 8, 9]
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"""
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Permissible value for memory level parameter.
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Higher values use more memory, but are faster and produce smaller output. The default is 8.
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"""
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@public
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class PerMessageDeflateOffer(PerMessageCompressOffer, PerMessageDeflateMixin):
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"""
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Set of extension parameters for `permessage-deflate` WebSocket extension
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offered by a client to a server.
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"""
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@classmethod
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def parse(cls, params):
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"""
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Parses a WebSocket extension offer for `permessage-deflate` provided by a client to a server.
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:param params: Output from :func:`autobahn.websocket.WebSocketProtocol._parseExtensionsHeader`.
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:type params: list
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:returns: A new instance of :class:`autobahn.compress.PerMessageDeflateOffer`.
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:rtype: obj
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"""
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# extension parameter defaults
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accept_max_window_bits = False
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accept_no_context_takeover = True
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# accept_no_context_takeover = False # FIXME: this may change in draft
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request_max_window_bits = 0
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request_no_context_takeover = False
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# verify/parse client ("client-to-server direction") parameters of permessage-deflate offer
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for p in params:
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if len(params[p]) > 1:
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raise Exception("multiple occurrence of extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
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val = params[p][0]
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if p == 'client_max_window_bits':
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#
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# see: https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression-18
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# 8.1.2.2. client_max_window_bits
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# ".. This parameter has no value or a decimal integer value without
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# leading zeroes between 9 to 15 inclusive ..""
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# noinspection PySimplifyBooleanCheck
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if val is not True:
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try:
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val = int(val)
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except:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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if val not in PerMessageDeflateMixin.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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# FIXME (maybe): possibly forward/process the client hint!
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# accept_max_window_bits = val
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accept_max_window_bits = True
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else:
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accept_max_window_bits = True
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elif p == 'client_no_context_takeover':
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# noinspection PySimplifyBooleanCheck
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if val is not True:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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accept_no_context_takeover = True
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elif p == 'server_max_window_bits':
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try:
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val = int(val)
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except:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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if val not in PerMessageDeflateMixin.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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request_max_window_bits = val
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elif p == 'server_no_context_takeover':
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# noinspection PySimplifyBooleanCheck
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if val is not True:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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request_no_context_takeover = True
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else:
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raise Exception("illegal extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
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offer = cls(accept_no_context_takeover,
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accept_max_window_bits,
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request_no_context_takeover,
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request_max_window_bits)
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return offer
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def __init__(self,
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accept_no_context_takeover=True,
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accept_max_window_bits=True,
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request_no_context_takeover=False,
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request_max_window_bits=0):
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"""
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:param accept_no_context_takeover: When ``True``, the client accepts the "no context takeover" feature.
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:type accept_no_context_takeover: bool
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:param accept_max_window_bits: When ``True``, the client accepts setting "max window size".
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:type accept_max_window_bits: bool
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:param request_no_context_takeover: When ``True``, the client request the "no context takeover" feature.
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:type request_no_context_takeover: bool
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:param request_max_window_bits: When non-zero, the client requests the given "max window size" (must be
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and integer from the interval ``[9..15]``).
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:type request_max_window_bits: int
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"""
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if type(accept_no_context_takeover) != bool:
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raise Exception("invalid type %s for accept_no_context_takeover" % type(accept_no_context_takeover))
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self.accept_no_context_takeover = accept_no_context_takeover
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if type(accept_max_window_bits) != bool:
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raise Exception("invalid type %s for accept_max_window_bits" % type(accept_max_window_bits))
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self.accept_max_window_bits = accept_max_window_bits
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if type(request_no_context_takeover) != bool:
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raise Exception("invalid type %s for request_no_context_takeover" % type(request_no_context_takeover))
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self.request_no_context_takeover = request_no_context_takeover
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if request_max_window_bits != 0 and request_max_window_bits not in self.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("invalid value %s for request_max_window_bits - permissible values %s" % (request_max_window_bits, self.WINDOW_SIZE_PERMISSIBLE_VALUES))
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self.request_max_window_bits = request_max_window_bits
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def get_extension_string(self):
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"""
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Returns the WebSocket extension configuration string as sent to the server.
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:returns: PMCE configuration string.
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:rtype: str
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"""
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pmce_string = self.EXTENSION_NAME
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if self.accept_no_context_takeover:
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pmce_string += "; client_no_context_takeover"
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if self.accept_max_window_bits:
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pmce_string += "; client_max_window_bits"
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if self.request_no_context_takeover:
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pmce_string += "; server_no_context_takeover"
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if self.request_max_window_bits != 0:
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pmce_string += "; server_max_window_bits=%d" % self.request_max_window_bits
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return pmce_string
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def __json__(self):
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"""
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Returns a JSON serializable object representation.
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:returns: JSON serializable representation.
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:rtype: dict
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"""
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return {'extension': self.EXTENSION_NAME,
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'accept_no_context_takeover': self.accept_no_context_takeover,
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'accept_max_window_bits': self.accept_max_window_bits,
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'request_no_context_takeover': self.request_no_context_takeover,
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'request_max_window_bits': self.request_max_window_bits}
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def __repr__(self):
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"""
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Returns Python object representation that can be eval'ed to reconstruct the object.
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:returns: Python string representation.
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:rtype: str
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"""
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return "PerMessageDeflateOffer(accept_no_context_takeover = %s, accept_max_window_bits = %s, request_no_context_takeover = %s, request_max_window_bits = %s)" % (self.accept_no_context_takeover, self.accept_max_window_bits, self.request_no_context_takeover, self.request_max_window_bits)
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@public
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class PerMessageDeflateOfferAccept(PerMessageCompressOfferAccept, PerMessageDeflateMixin):
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"""
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Set of parameters with which to accept an `permessage-deflate` offer
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from a client by a server.
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"""
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def __init__(self,
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offer,
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request_no_context_takeover=False,
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request_max_window_bits=0,
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no_context_takeover=None,
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window_bits=None,
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mem_level=None,
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max_message_size=None):
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"""
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:param offer: The offer being accepted.
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:type offer: Instance of :class:`autobahn.compress.PerMessageDeflateOffer`.
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:param request_no_context_takeover: When ``True``, the server requests the "no context takeover" feature.
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:type request_no_context_takeover: bool
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:param request_max_window_bits: When non-zero, the server requests the given "max window size" (must be
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and integer from the interval ``[9..15]``).
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:param request_max_window_bits: int
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:param no_context_takeover: Override server ("server-to-client direction") context takeover (this must
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be compatible with the offer).
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:type no_context_takeover: bool
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:param window_bits: Override server ("server-to-client direction") window size (this must be
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compatible with the offer).
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:type window_bits: int
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:param mem_level: Set server ("server-to-client direction") memory level.
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:type mem_level: int
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"""
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if not isinstance(offer, PerMessageDeflateOffer):
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raise Exception("invalid type %s for offer" % type(offer))
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self.offer = offer
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if type(request_no_context_takeover) != bool:
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raise Exception("invalid type %s for request_no_context_takeover" % type(request_no_context_takeover))
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if request_no_context_takeover and not offer.accept_no_context_takeover:
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raise Exception("invalid value %s for request_no_context_takeover - feature unsupported by client" % request_no_context_takeover)
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self.request_no_context_takeover = request_no_context_takeover
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if request_max_window_bits != 0 and request_max_window_bits not in self.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("invalid value %s for request_max_window_bits - permissible values %s" % (request_max_window_bits, self.WINDOW_SIZE_PERMISSIBLE_VALUES))
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if request_max_window_bits != 0 and not offer.accept_max_window_bits:
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raise Exception("invalid value %s for request_max_window_bits - feature unsupported by client" % request_max_window_bits)
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self.request_max_window_bits = request_max_window_bits
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if no_context_takeover is not None:
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if type(no_context_takeover) != bool:
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raise Exception("invalid type %s for no_context_takeover" % type(no_context_takeover))
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if offer.request_no_context_takeover and not no_context_takeover:
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raise Exception("invalid value %s for no_context_takeover - client requested feature" % no_context_takeover)
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self.no_context_takeover = no_context_takeover
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if window_bits is not None:
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if window_bits not in self.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("invalid value %s for window_bits - permissible values %s" % (window_bits, self.WINDOW_SIZE_PERMISSIBLE_VALUES))
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if offer.request_max_window_bits != 0 and window_bits > offer.request_max_window_bits:
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raise Exception("invalid value %s for window_bits - client requested lower maximum value" % window_bits)
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self.window_bits = window_bits
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if mem_level is not None:
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if mem_level not in self.MEM_LEVEL_PERMISSIBLE_VALUES:
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raise Exception("invalid value %s for mem_level - permissible values %s" % (mem_level, self.MEM_LEVEL_PERMISSIBLE_VALUES))
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self.mem_level = mem_level
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self.max_message_size = max_message_size # clamp/check values..?
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def get_extension_string(self):
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"""
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Returns the WebSocket extension configuration string as sent to the server.
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:returns: PMCE configuration string.
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:rtype: str
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"""
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pmce_string = self.EXTENSION_NAME
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if self.offer.request_no_context_takeover:
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pmce_string += "; server_no_context_takeover"
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if self.offer.request_max_window_bits != 0:
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pmce_string += "; server_max_window_bits=%d" % self.offer.request_max_window_bits
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if self.request_no_context_takeover:
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pmce_string += "; client_no_context_takeover"
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if self.request_max_window_bits != 0:
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pmce_string += "; client_max_window_bits=%d" % self.request_max_window_bits
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return pmce_string
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def __json__(self):
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"""
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Returns a JSON serializable object representation.
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:returns: JSON serializable representation.
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:rtype: dict
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"""
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return {
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'extension': self.EXTENSION_NAME,
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'offer': self.offer.__json__(),
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'request_no_context_takeover': self.request_no_context_takeover,
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'request_max_window_bits': self.request_max_window_bits,
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'no_context_takeover': self.no_context_takeover,
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'window_bits': self.window_bits,
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'mem_level': self.mem_level,
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'max_message_size': self.max_message_size,
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}
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def __repr__(self):
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"""
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Returns Python object representation that can be eval'ed to reconstruct the object.
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:returns: Python string representation.
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:rtype: str
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"""
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return "PerMessageDeflateOfferAccept(offer = %s, request_no_context_takeover = %s, request_max_window_bits = %s, no_context_takeover = %s, window_bits = %s, mem_level = %s, max_message_size = %s)" % (self.offer.__repr__(), self.request_no_context_takeover, self.request_max_window_bits, self.no_context_takeover, self.window_bits, self.mem_level, self.max_message_size)
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@public
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class PerMessageDeflateResponse(PerMessageCompressResponse, PerMessageDeflateMixin):
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"""
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Set of parameters for `permessage-deflate` responded by server.
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"""
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@classmethod
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def parse(cls, params):
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"""
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Parses a WebSocket extension response for `permessage-deflate` provided by a server to a client.
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:param params: Output from :func:`autobahn.websocket.WebSocketProtocol._parseExtensionsHeader`.
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:type params: list
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:returns: A new instance of :class:`autobahn.compress.PerMessageDeflateResponse`.
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:rtype: obj
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"""
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client_max_window_bits = 0
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client_no_context_takeover = False
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server_max_window_bits = 0
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server_no_context_takeover = False
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for p in params:
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if len(params[p]) > 1:
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raise Exception("multiple occurrence of extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
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val = params[p][0]
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if p == 'client_max_window_bits':
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try:
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val = int(val)
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except:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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if val not in PerMessageDeflateMixin.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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client_max_window_bits = val
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elif p == 'client_no_context_takeover':
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# noinspection PySimplifyBooleanCheck
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if val is not True:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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client_no_context_takeover = True
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elif p == 'server_max_window_bits':
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try:
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val = int(val)
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except:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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if val not in PerMessageDeflateMixin.WINDOW_SIZE_PERMISSIBLE_VALUES:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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server_max_window_bits = val
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elif p == 'server_no_context_takeover':
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# noinspection PySimplifyBooleanCheck
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if val is not True:
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raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
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else:
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server_no_context_takeover = True
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else:
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raise Exception("illegal extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
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response = cls(client_max_window_bits,
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client_no_context_takeover,
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server_max_window_bits,
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server_no_context_takeover)
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return response
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def __init__(self,
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client_max_window_bits,
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client_no_context_takeover,
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server_max_window_bits,
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server_no_context_takeover):
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"""
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:param client_max_window_bits: FIXME
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:type client_max_window_bits: int
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:param client_no_context_takeover: FIXME
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:type client_no_context_takeover: bool
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:param server_max_window_bits: FIXME
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:type server_max_window_bits: int
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:param server_no_context_takeover: FIXME
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:type server_no_context_takeover: bool
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"""
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self.client_max_window_bits = client_max_window_bits
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self.client_no_context_takeover = client_no_context_takeover
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self.server_max_window_bits = server_max_window_bits
|
|
self.server_no_context_takeover = server_no_context_takeover
|
|
|
|
def __json__(self):
|
|
"""
|
|
Returns a JSON serializable object representation.
|
|
|
|
:returns: JSON serializable representation.
|
|
:rtype: dict
|
|
"""
|
|
return {'extension': self.EXTENSION_NAME,
|
|
'client_max_window_bits': self.client_max_window_bits,
|
|
'client_no_context_takeover': self.client_no_context_takeover,
|
|
'server_max_window_bits': self.server_max_window_bits,
|
|
'server_no_context_takeover': self.server_no_context_takeover}
|
|
|
|
def __repr__(self):
|
|
"""
|
|
Returns Python object representation that can be eval'ed to reconstruct the object.
|
|
|
|
:returns: Python string representation.
|
|
:rtype: str
|
|
"""
|
|
return "PerMessageDeflateResponse(client_max_window_bits = %s, client_no_context_takeover = %s, server_max_window_bits = %s, server_no_context_takeover = %s)" % (self.client_max_window_bits, self.client_no_context_takeover, self.server_max_window_bits, self.server_no_context_takeover)
|
|
|
|
|
|
@public
|
|
class PerMessageDeflateResponseAccept(PerMessageCompressResponseAccept, PerMessageDeflateMixin):
|
|
"""
|
|
Set of parameters with which to accept an `permessage-deflate` response
|
|
from a server by a client.
|
|
"""
|
|
|
|
def __init__(self,
|
|
response,
|
|
no_context_takeover=None,
|
|
window_bits=None,
|
|
mem_level=None,
|
|
max_message_size=None):
|
|
"""
|
|
|
|
:param response: The response being accepted.
|
|
:type response: Instance of :class:`autobahn.compress.PerMessageDeflateResponse`.
|
|
:param no_context_takeover: Override client ("client-to-server direction") context takeover (this must be compatible with response).
|
|
:type no_context_takeover: bool
|
|
:param window_bits: Override client ("client-to-server direction") window size (this must be compatible with response).
|
|
:type window_bits: int
|
|
:param mem_level: Set client ("client-to-server direction") memory level.
|
|
:type mem_level: int
|
|
"""
|
|
if not isinstance(response, PerMessageDeflateResponse):
|
|
raise Exception("invalid type %s for response" % type(response))
|
|
|
|
self.response = response
|
|
|
|
if no_context_takeover is not None:
|
|
if type(no_context_takeover) != bool:
|
|
raise Exception("invalid type %s for no_context_takeover" % type(no_context_takeover))
|
|
|
|
if response.client_no_context_takeover and not no_context_takeover:
|
|
raise Exception("invalid value %s for no_context_takeover - server requested feature" % no_context_takeover)
|
|
|
|
self.no_context_takeover = no_context_takeover
|
|
|
|
if window_bits is not None:
|
|
if window_bits not in self.WINDOW_SIZE_PERMISSIBLE_VALUES:
|
|
raise Exception("invalid value %s for window_bits - permissible values %s" % (window_bits, self.WINDOW_SIZE_PERMISSIBLE_VALUES))
|
|
|
|
if response.client_max_window_bits != 0 and window_bits > response.client_max_window_bits:
|
|
raise Exception("invalid value %s for window_bits - server requested lower maximum value" % window_bits)
|
|
|
|
self.window_bits = window_bits
|
|
|
|
if mem_level is not None:
|
|
if mem_level not in self.MEM_LEVEL_PERMISSIBLE_VALUES:
|
|
raise Exception("invalid value %s for mem_level - permissible values %s" % (mem_level, self.MEM_LEVEL_PERMISSIBLE_VALUES))
|
|
|
|
self.mem_level = mem_level
|
|
self.max_message_size = max_message_size
|
|
|
|
def __json__(self):
|
|
"""
|
|
Returns a JSON serializable object representation.
|
|
|
|
:returns: JSON serializable representation.
|
|
:rtype: dict
|
|
"""
|
|
return {'extension': self.EXTENSION_NAME,
|
|
'response': self.response.__json__(),
|
|
'no_context_takeover': self.no_context_takeover,
|
|
'window_bits': self.window_bits,
|
|
'mem_level': self.mem_level}
|
|
|
|
def __repr__(self):
|
|
"""
|
|
Returns Python object representation that can be eval'ed to reconstruct the object.
|
|
|
|
:returns: Python string representation.
|
|
:rtype: str
|
|
"""
|
|
return "PerMessageDeflateResponseAccept(response = %s, no_context_takeover = %s, window_bits = %s, mem_level = %s)" % (self.response.__repr__(), self.no_context_takeover, self.window_bits, self.mem_level)
|
|
|
|
|
|
# noinspection PyArgumentList
|
|
class PerMessageDeflate(PerMessageCompress, PerMessageDeflateMixin):
|
|
"""
|
|
`permessage-deflate` WebSocket extension processor.
|
|
"""
|
|
DEFAULT_WINDOW_BITS = zlib.MAX_WBITS
|
|
DEFAULT_MEM_LEVEL = 8
|
|
|
|
@classmethod
|
|
def create_from_response_accept(cls, is_server, accept):
|
|
# accept: instance of PerMessageDeflateResponseAccept
|
|
pmce = cls(
|
|
is_server,
|
|
accept.response.server_no_context_takeover,
|
|
accept.no_context_takeover if accept.no_context_takeover is not None else accept.response.client_no_context_takeover,
|
|
accept.response.server_max_window_bits,
|
|
accept.window_bits if accept.window_bits is not None else accept.response.client_max_window_bits,
|
|
accept.mem_level,
|
|
accept.max_message_size,
|
|
)
|
|
return pmce
|
|
|
|
@classmethod
|
|
def create_from_offer_accept(cls, is_server, accept):
|
|
# accept: instance of PerMessageDeflateOfferAccept
|
|
pmce = cls(is_server,
|
|
accept.no_context_takeover if accept.no_context_takeover is not None else accept.offer.request_no_context_takeover,
|
|
accept.request_no_context_takeover,
|
|
accept.window_bits if accept.window_bits is not None else accept.offer.request_max_window_bits,
|
|
accept.request_max_window_bits,
|
|
accept.mem_level,
|
|
accept.max_message_size,)
|
|
return pmce
|
|
|
|
def __init__(self,
|
|
is_server,
|
|
server_no_context_takeover,
|
|
client_no_context_takeover,
|
|
server_max_window_bits,
|
|
client_max_window_bits,
|
|
mem_level,
|
|
max_message_size=None):
|
|
self._is_server = is_server
|
|
|
|
self.server_no_context_takeover = server_no_context_takeover
|
|
self.client_no_context_takeover = client_no_context_takeover
|
|
|
|
self.server_max_window_bits = server_max_window_bits if server_max_window_bits != 0 else self.DEFAULT_WINDOW_BITS
|
|
self.client_max_window_bits = client_max_window_bits if client_max_window_bits != 0 else self.DEFAULT_WINDOW_BITS
|
|
|
|
self.mem_level = mem_level if mem_level else self.DEFAULT_MEM_LEVEL
|
|
self.max_message_size = max_message_size # None means "no limit"
|
|
|
|
self._compressor = None
|
|
self._decompressor = None
|
|
|
|
def __json__(self):
|
|
return {'extension': self.EXTENSION_NAME,
|
|
'is_server': self._is_server,
|
|
'server_no_context_takeover': self.server_no_context_takeover,
|
|
'client_no_context_takeover': self.client_no_context_takeover,
|
|
'server_max_window_bits': self.server_max_window_bits,
|
|
'client_max_window_bits': self.client_max_window_bits,
|
|
'mem_level': self.mem_level}
|
|
|
|
def __repr__(self):
|
|
return "PerMessageDeflate(is_server = %s, server_no_context_takeover = %s, client_no_context_takeover = %s, server_max_window_bits = %s, client_max_window_bits = %s, mem_level = %s)" % (self._is_server, self.server_no_context_takeover, self.client_no_context_takeover, self.server_max_window_bits, self.client_max_window_bits, self.mem_level)
|
|
|
|
def start_compress_message(self):
|
|
# compressobj([level[, method[, wbits[, mem_level[, strategy]]]]])
|
|
# http://bugs.python.org/issue19278
|
|
# http://hg.python.org/cpython/rev/c54c8e71b79a
|
|
if self._is_server:
|
|
if self._compressor is None or self.server_no_context_takeover:
|
|
self._compressor = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -self.server_max_window_bits, self.mem_level)
|
|
else:
|
|
if self._compressor is None or self.client_no_context_takeover:
|
|
self._compressor = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -self.client_max_window_bits, self.mem_level)
|
|
|
|
def compress_message_data(self, data):
|
|
return self._compressor.compress(data)
|
|
|
|
def end_compress_message(self):
|
|
data = self._compressor.flush(zlib.Z_SYNC_FLUSH)
|
|
return data[:-4]
|
|
|
|
def start_decompress_message(self):
|
|
if self._is_server:
|
|
if self._decompressor is None or self.client_no_context_takeover:
|
|
self._decompressor = zlib.decompressobj(-self.client_max_window_bits)
|
|
else:
|
|
if self._decompressor is None or self.server_no_context_takeover:
|
|
self._decompressor = zlib.decompressobj(-self.server_max_window_bits)
|
|
|
|
def decompress_message_data(self, data):
|
|
if self.max_message_size is not None:
|
|
return self._decompressor.decompress(data, self.max_message_size)
|
|
return self._decompressor.decompress(data)
|
|
|
|
def end_decompress_message(self):
|
|
# Eat stripped LEN and NLEN field of a non-compressed block added
|
|
# for Z_SYNC_FLUSH.
|
|
self._decompressor.decompress(b'\x00\x00\xff\xff')
|