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-rw-r--r--testing/mochitest/pywebsocket3/mod_pywebsocket/extensions.py473
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diff --git a/testing/mochitest/pywebsocket3/mod_pywebsocket/extensions.py b/testing/mochitest/pywebsocket3/mod_pywebsocket/extensions.py
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+# Copyright 2012, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+# * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from __future__ import absolute_import
+from mod_pywebsocket import common
+from mod_pywebsocket import util
+from mod_pywebsocket.http_header_util import quote_if_necessary
+
+# The list of available server side extension processor classes.
+_available_processors = {}
+
+
+class ExtensionProcessorInterface(object):
+ def __init__(self, request):
+ self._logger = util.get_class_logger(self)
+
+ self._request = request
+ self._active = True
+
+ def request(self):
+ return self._request
+
+ def name(self):
+ return None
+
+ def check_consistency_with_other_processors(self, processors):
+ pass
+
+ def set_active(self, active):
+ self._active = active
+
+ def is_active(self):
+ return self._active
+
+ def _get_extension_response_internal(self):
+ return None
+
+ def get_extension_response(self):
+ if not self._active:
+ self._logger.debug('Extension %s is deactivated', self.name())
+ return None
+
+ response = self._get_extension_response_internal()
+ if response is None:
+ self._active = False
+ return response
+
+ def _setup_stream_options_internal(self, stream_options):
+ pass
+
+ def setup_stream_options(self, stream_options):
+ if self._active:
+ self._setup_stream_options_internal(stream_options)
+
+
+def _log_outgoing_compression_ratio(logger, original_bytes, filtered_bytes,
+ average_ratio):
+ # Print inf when ratio is not available.
+ ratio = float('inf')
+ if original_bytes != 0:
+ ratio = float(filtered_bytes) / original_bytes
+
+ logger.debug('Outgoing compression ratio: %f (average: %f)' %
+ (ratio, average_ratio))
+
+
+def _log_incoming_compression_ratio(logger, received_bytes, filtered_bytes,
+ average_ratio):
+ # Print inf when ratio is not available.
+ ratio = float('inf')
+ if filtered_bytes != 0:
+ ratio = float(received_bytes) / filtered_bytes
+
+ logger.debug('Incoming compression ratio: %f (average: %f)' %
+ (ratio, average_ratio))
+
+
+def _parse_window_bits(bits):
+ """Return parsed integer value iff the given string conforms to the
+ grammar of the window bits extension parameters.
+ """
+
+ if bits is None:
+ raise ValueError('Value is required')
+
+ # For non integer values such as "10.0", ValueError will be raised.
+ int_bits = int(bits)
+
+ # First condition is to drop leading zero case e.g. "08".
+ if bits != str(int_bits) or int_bits < 8 or int_bits > 15:
+ raise ValueError('Invalid value: %r' % bits)
+
+ return int_bits
+
+
+class _AverageRatioCalculator(object):
+ """Stores total bytes of original and result data, and calculates average
+ result / original ratio.
+ """
+ def __init__(self):
+ self._total_original_bytes = 0
+ self._total_result_bytes = 0
+
+ def add_original_bytes(self, value):
+ self._total_original_bytes += value
+
+ def add_result_bytes(self, value):
+ self._total_result_bytes += value
+
+ def get_average_ratio(self):
+ if self._total_original_bytes != 0:
+ return (float(self._total_result_bytes) /
+ self._total_original_bytes)
+ else:
+ return float('inf')
+
+
+class PerMessageDeflateExtensionProcessor(ExtensionProcessorInterface):
+ """permessage-deflate extension processor.
+
+ Specification:
+ http://tools.ietf.org/html/draft-ietf-hybi-permessage-compression-08
+ """
+
+ _SERVER_MAX_WINDOW_BITS_PARAM = 'server_max_window_bits'
+ _SERVER_NO_CONTEXT_TAKEOVER_PARAM = 'server_no_context_takeover'
+ _CLIENT_MAX_WINDOW_BITS_PARAM = 'client_max_window_bits'
+ _CLIENT_NO_CONTEXT_TAKEOVER_PARAM = 'client_no_context_takeover'
+
+ def __init__(self, request):
+ """Construct PerMessageDeflateExtensionProcessor."""
+
+ ExtensionProcessorInterface.__init__(self, request)
+ self._logger = util.get_class_logger(self)
+
+ self._preferred_client_max_window_bits = None
+ self._client_no_context_takeover = False
+
+ def name(self):
+ # This method returns "deflate" (not "permessage-deflate") for
+ # compatibility.
+ return 'deflate'
+
+ def _get_extension_response_internal(self):
+ for name in self._request.get_parameter_names():
+ if name not in [
+ self._SERVER_MAX_WINDOW_BITS_PARAM,
+ self._SERVER_NO_CONTEXT_TAKEOVER_PARAM,
+ self._CLIENT_MAX_WINDOW_BITS_PARAM
+ ]:
+ self._logger.debug('Unknown parameter: %r', name)
+ return None
+
+ server_max_window_bits = None
+ if self._request.has_parameter(self._SERVER_MAX_WINDOW_BITS_PARAM):
+ server_max_window_bits = self._request.get_parameter_value(
+ self._SERVER_MAX_WINDOW_BITS_PARAM)
+ try:
+ server_max_window_bits = _parse_window_bits(
+ server_max_window_bits)
+ except ValueError as e:
+ self._logger.debug('Bad %s parameter: %r',
+ self._SERVER_MAX_WINDOW_BITS_PARAM, e)
+ return None
+
+ server_no_context_takeover = self._request.has_parameter(
+ self._SERVER_NO_CONTEXT_TAKEOVER_PARAM)
+ if (server_no_context_takeover and self._request.get_parameter_value(
+ self._SERVER_NO_CONTEXT_TAKEOVER_PARAM) is not None):
+ self._logger.debug('%s parameter must not have a value: %r',
+ self._SERVER_NO_CONTEXT_TAKEOVER_PARAM,
+ server_no_context_takeover)
+ return None
+
+ # client_max_window_bits from a client indicates whether the client can
+ # accept client_max_window_bits from a server or not.
+ client_client_max_window_bits = self._request.has_parameter(
+ self._CLIENT_MAX_WINDOW_BITS_PARAM)
+ if (client_client_max_window_bits
+ and self._request.get_parameter_value(
+ self._CLIENT_MAX_WINDOW_BITS_PARAM) is not None):
+ self._logger.debug(
+ '%s parameter must not have a value in a '
+ 'client\'s opening handshake: %r',
+ self._CLIENT_MAX_WINDOW_BITS_PARAM,
+ client_client_max_window_bits)
+ return None
+
+ self._rfc1979_deflater = util._RFC1979Deflater(
+ server_max_window_bits, server_no_context_takeover)
+
+ # Note that we prepare for incoming messages compressed with window
+ # bits upto 15 regardless of the client_max_window_bits value to be
+ # sent to the client.
+ self._rfc1979_inflater = util._RFC1979Inflater()
+
+ self._framer = _PerMessageDeflateFramer(server_max_window_bits,
+ server_no_context_takeover)
+ self._framer.set_bfinal(False)
+ self._framer.set_compress_outgoing_enabled(True)
+
+ response = common.ExtensionParameter(self._request.name())
+
+ if server_max_window_bits is not None:
+ response.add_parameter(self._SERVER_MAX_WINDOW_BITS_PARAM,
+ str(server_max_window_bits))
+
+ if server_no_context_takeover:
+ response.add_parameter(self._SERVER_NO_CONTEXT_TAKEOVER_PARAM,
+ None)
+
+ if self._preferred_client_max_window_bits is not None:
+ if not client_client_max_window_bits:
+ self._logger.debug(
+ 'Processor is configured to use %s but '
+ 'the client cannot accept it',
+ self._CLIENT_MAX_WINDOW_BITS_PARAM)
+ return None
+ response.add_parameter(self._CLIENT_MAX_WINDOW_BITS_PARAM,
+ str(self._preferred_client_max_window_bits))
+
+ if self._client_no_context_takeover:
+ response.add_parameter(self._CLIENT_NO_CONTEXT_TAKEOVER_PARAM,
+ None)
+
+ self._logger.debug('Enable %s extension ('
+ 'request: server_max_window_bits=%s; '
+ 'server_no_context_takeover=%r, '
+ 'response: client_max_window_bits=%s; '
+ 'client_no_context_takeover=%r)' %
+ (self._request.name(), server_max_window_bits,
+ server_no_context_takeover,
+ self._preferred_client_max_window_bits,
+ self._client_no_context_takeover))
+
+ return response
+
+ def _setup_stream_options_internal(self, stream_options):
+ self._framer.setup_stream_options(stream_options)
+
+ def set_client_max_window_bits(self, value):
+ """If this option is specified, this class adds the
+ client_max_window_bits extension parameter to the handshake response,
+ but doesn't reduce the LZ77 sliding window size of its inflater.
+ I.e., you can use this for testing client implementation but cannot
+ reduce memory usage of this class.
+
+ If this method has been called with True and an offer without the
+ client_max_window_bits extension parameter is received,
+ - (When processing the permessage-deflate extension) this processor
+ declines the request.
+ - (When processing the permessage-compress extension) this processor
+ accepts the request.
+ """
+
+ self._preferred_client_max_window_bits = value
+
+ def set_client_no_context_takeover(self, value):
+ """If this option is specified, this class adds the
+ client_no_context_takeover extension parameter to the handshake
+ response, but doesn't reset inflater for each message. I.e., you can
+ use this for testing client implementation but cannot reduce memory
+ usage of this class.
+ """
+
+ self._client_no_context_takeover = value
+
+ def set_bfinal(self, value):
+ self._framer.set_bfinal(value)
+
+ def enable_outgoing_compression(self):
+ self._framer.set_compress_outgoing_enabled(True)
+
+ def disable_outgoing_compression(self):
+ self._framer.set_compress_outgoing_enabled(False)
+
+
+class _PerMessageDeflateFramer(object):
+ """A framer for extensions with per-message DEFLATE feature."""
+ def __init__(self, deflate_max_window_bits, deflate_no_context_takeover):
+ self._logger = util.get_class_logger(self)
+
+ self._rfc1979_deflater = util._RFC1979Deflater(
+ deflate_max_window_bits, deflate_no_context_takeover)
+
+ self._rfc1979_inflater = util._RFC1979Inflater()
+
+ self._bfinal = False
+
+ self._compress_outgoing_enabled = False
+
+ # True if a message is fragmented and compression is ongoing.
+ self._compress_ongoing = False
+
+ # Calculates
+ # (Total outgoing bytes supplied to this filter) /
+ # (Total bytes sent to the network after applying this filter)
+ self._outgoing_average_ratio_calculator = _AverageRatioCalculator()
+
+ # Calculates
+ # (Total bytes received from the network) /
+ # (Total incoming bytes obtained after applying this filter)
+ self._incoming_average_ratio_calculator = _AverageRatioCalculator()
+
+ def set_bfinal(self, value):
+ self._bfinal = value
+
+ def set_compress_outgoing_enabled(self, value):
+ self._compress_outgoing_enabled = value
+
+ def _process_incoming_message(self, message, decompress):
+ if not decompress:
+ return message
+
+ received_payload_size = len(message)
+ self._incoming_average_ratio_calculator.add_result_bytes(
+ received_payload_size)
+
+ message = self._rfc1979_inflater.filter(message)
+
+ filtered_payload_size = len(message)
+ self._incoming_average_ratio_calculator.add_original_bytes(
+ filtered_payload_size)
+
+ _log_incoming_compression_ratio(
+ self._logger, received_payload_size, filtered_payload_size,
+ self._incoming_average_ratio_calculator.get_average_ratio())
+
+ return message
+
+ def _process_outgoing_message(self, message, end, binary):
+ if not binary:
+ message = message.encode('utf-8')
+
+ if not self._compress_outgoing_enabled:
+ return message
+
+ original_payload_size = len(message)
+ self._outgoing_average_ratio_calculator.add_original_bytes(
+ original_payload_size)
+
+ message = self._rfc1979_deflater.filter(message,
+ end=end,
+ bfinal=self._bfinal)
+
+ filtered_payload_size = len(message)
+ self._outgoing_average_ratio_calculator.add_result_bytes(
+ filtered_payload_size)
+
+ _log_outgoing_compression_ratio(
+ self._logger, original_payload_size, filtered_payload_size,
+ self._outgoing_average_ratio_calculator.get_average_ratio())
+
+ if not self._compress_ongoing:
+ self._outgoing_frame_filter.set_compression_bit()
+ self._compress_ongoing = not end
+ return message
+
+ def _process_incoming_frame(self, frame):
+ if frame.rsv1 == 1 and not common.is_control_opcode(frame.opcode):
+ self._incoming_message_filter.decompress_next_message()
+ frame.rsv1 = 0
+
+ def _process_outgoing_frame(self, frame, compression_bit):
+ if (not compression_bit or common.is_control_opcode(frame.opcode)):
+ return
+
+ frame.rsv1 = 1
+
+ def setup_stream_options(self, stream_options):
+ """Creates filters and sets them to the StreamOptions."""
+ class _OutgoingMessageFilter(object):
+ def __init__(self, parent):
+ self._parent = parent
+
+ def filter(self, message, end=True, binary=False):
+ return self._parent._process_outgoing_message(
+ message, end, binary)
+
+ class _IncomingMessageFilter(object):
+ def __init__(self, parent):
+ self._parent = parent
+ self._decompress_next_message = False
+
+ def decompress_next_message(self):
+ self._decompress_next_message = True
+
+ def filter(self, message):
+ message = self._parent._process_incoming_message(
+ message, self._decompress_next_message)
+ self._decompress_next_message = False
+ return message
+
+ self._outgoing_message_filter = _OutgoingMessageFilter(self)
+ self._incoming_message_filter = _IncomingMessageFilter(self)
+ stream_options.outgoing_message_filters.append(
+ self._outgoing_message_filter)
+ stream_options.incoming_message_filters.append(
+ self._incoming_message_filter)
+
+ class _OutgoingFrameFilter(object):
+ def __init__(self, parent):
+ self._parent = parent
+ self._set_compression_bit = False
+
+ def set_compression_bit(self):
+ self._set_compression_bit = True
+
+ def filter(self, frame):
+ self._parent._process_outgoing_frame(frame,
+ self._set_compression_bit)
+ self._set_compression_bit = False
+
+ class _IncomingFrameFilter(object):
+ def __init__(self, parent):
+ self._parent = parent
+
+ def filter(self, frame):
+ self._parent._process_incoming_frame(frame)
+
+ self._outgoing_frame_filter = _OutgoingFrameFilter(self)
+ self._incoming_frame_filter = _IncomingFrameFilter(self)
+ stream_options.outgoing_frame_filters.append(
+ self._outgoing_frame_filter)
+ stream_options.incoming_frame_filters.append(
+ self._incoming_frame_filter)
+
+ stream_options.encode_text_message_to_utf8 = False
+
+
+_available_processors[common.PERMESSAGE_DEFLATE_EXTENSION] = (
+ PerMessageDeflateExtensionProcessor)
+
+
+def get_extension_processor(extension_request):
+ """Given an ExtensionParameter representing an extension offer received
+ from a client, configures and returns an instance of the corresponding
+ extension processor class.
+ """
+
+ processor_class = _available_processors.get(extension_request.name())
+ if processor_class is None:
+ return None
+ return processor_class(extension_request)
+
+
+# vi:sts=4 sw=4 et