deb-python-autobahn/autobahn/autobahn/websocket/compress_bzip2.py

442 lines
18 KiB
Python

###############################################################################
#
# The MIT License (MIT)
#
# Copyright (c) Tavendo GmbH
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
###############################################################################
from __future__ import absolute_import
import bz2
from autobahn.websocket.compress_base import PerMessageCompressOffer, \
PerMessageCompressOfferAccept, \
PerMessageCompressResponse, \
PerMessageCompressResponseAccept, \
PerMessageCompress
__all__ = (
'PerMessageBzip2Mixin',
'PerMessageBzip2Offer',
'PerMessageBzip2OfferAccept',
'PerMessageBzip2Response',
'PerMessageBzip2ResponseAccept',
'PerMessageBzip2',
)
class PerMessageBzip2Mixin:
"""
Mixin class for this extension.
"""
EXTENSION_NAME = "permessage-bzip2"
"""
Name of this WebSocket extension.
"""
COMPRESS_LEVEL_PERMISSIBLE_VALUES = [1, 2, 3, 4, 5, 6, 7, 8, 9]
"""
Permissible value for compression level parameter.
"""
class PerMessageBzip2Offer(PerMessageCompressOffer, PerMessageBzip2Mixin):
"""
Set of extension parameters for `permessage-bzip2` WebSocket extension
offered by a client to a server.
"""
@classmethod
def parse(cls, params):
"""
Parses a WebSocket extension offer for `permessage-bzip2` provided by a client to a server.
:param params: Output from :func:`autobahn.websocket.WebSocketProtocol._parseExtensionsHeader`.
:type params: list
:returns: object -- A new instance of :class:`autobahn.compress.PerMessageBzip2Offer`.
"""
# extension parameter defaults
##
acceptMaxCompressLevel = False
requestMaxCompressLevel = 0
##
# verify/parse client ("client-to-server direction") parameters of permessage-bzip2 offer
##
for p in params:
if len(params[p]) > 1:
raise Exception("multiple occurrence of extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
val = params[p][0]
if p == 'client_max_compress_level':
# noinspection PySimplifyBooleanCheck
if val is not True:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
else:
acceptMaxCompressLevel = True
elif p == 'server_max_compress_level':
try:
val = int(val)
except:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
if val not in PerMessageBzip2Mixin.COMPRESS_LEVEL_PERMISSIBLE_VALUES:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
else:
requestMaxCompressLevel = val
else:
raise Exception("illegal extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
offer = cls(acceptMaxCompressLevel,
requestMaxCompressLevel)
return offer
def __init__(self,
acceptMaxCompressLevel=True,
requestMaxCompressLevel=0):
"""
Constructor.
:param acceptMaxCompressLevel: Iff true, client accepts "maximum compression level" parameter.
:type acceptMaxCompressLevel: bool
:param requestMaxCompressLevel: Iff non-zero, client requests given "maximum compression level" - must be 1-9.
:type requestMaxCompressLevel: int
"""
if type(acceptMaxCompressLevel) != bool:
raise Exception("invalid type %s for acceptMaxCompressLevel" % type(acceptMaxCompressLevel))
self.acceptMaxCompressLevel = acceptMaxCompressLevel
if requestMaxCompressLevel != 0 and requestMaxCompressLevel not in self.COMPRESS_LEVEL_PERMISSIBLE_VALUES:
raise Exception("invalid value %s for requestMaxCompressLevel - permissible values %s" % (requestMaxCompressLevel, self.COMPRESS_LEVEL_PERMISSIBLE_VALUES))
self.requestMaxCompressLevel = requestMaxCompressLevel
def getExtensionString(self):
"""
Returns the WebSocket extension configuration string as sent to the server.
:returns: str -- PMCE configuration string.
"""
pmceString = self.EXTENSION_NAME
if self.acceptMaxCompressLevel:
pmceString += "; client_max_compress_level"
if self.requestMaxCompressLevel != 0:
pmceString += "; server_max_compress_level=%d" % self.requestMaxCompressLevel
return pmceString
def __json__(self):
"""
Returns a JSON serializable object representation.
:returns: object -- JSON serializable representation.
"""
return {'extension': self.EXTENSION_NAME,
'acceptMaxCompressLevel': self.acceptMaxCompressLevel,
'requestMaxCompressLevel': self.requestMaxCompressLevel}
def __repr__(self):
"""
Returns Python object representation that can be eval'ed to reconstruct the object.
:returns: str -- Python string representation.
"""
return "PerMessageBzip2Offer(acceptMaxCompressLevel = %s, requestMaxCompressLevel = %s)" % (self.acceptMaxCompressLevel, self.requestMaxCompressLevel)
class PerMessageBzip2OfferAccept(PerMessageCompressOfferAccept, PerMessageBzip2Mixin):
"""
Set of parameters with which to accept an `permessage-bzip2` offer
from a client by a server.
"""
def __init__(self,
offer,
requestMaxCompressLevel=0,
compressLevel=None):
"""
Constructor.
:param offer: The offer being accepted.
:type offer: Instance of :class:`autobahn.compress.PerMessageBzip2Offer`.
:param requestMaxCompressLevel: Iff non-zero, server requests given "maximum compression level" - must be 1-9.
:type requestMaxCompressLevel: int
:param compressLevel: Override server ("server-to-client direction") compress level (this must be compatible with offer).
:type compressLevel: int
"""
if not isinstance(offer, PerMessageBzip2Offer):
raise Exception("invalid type %s for offer" % type(offer))
self.offer = offer
if requestMaxCompressLevel != 0 and requestMaxCompressLevel not in self.COMPRESS_LEVEL_PERMISSIBLE_VALUES:
raise Exception("invalid value %s for requestMaxCompressLevel - permissible values %s" % (requestMaxCompressLevel, self.COMPRESS_LEVEL_PERMISSIBLE_VALUES))
if requestMaxCompressLevel != 0 and not offer.acceptMaxCompressLevel:
raise Exception("invalid value %s for requestMaxCompressLevel - feature unsupported by client" % requestMaxCompressLevel)
self.requestMaxCompressLevel = requestMaxCompressLevel
if compressLevel is not None:
if compressLevel not in self.COMPRESS_LEVEL_PERMISSIBLE_VALUES:
raise Exception("invalid value %s for compressLevel - permissible values %s" % (compressLevel, self.COMPRESS_LEVEL_PERMISSIBLE_VALUES))
if offer.requestMaxCompressLevel != 0 and compressLevel > offer.requestMaxCompressLevel:
raise Exception("invalid value %s for compressLevel - client requested lower maximum value" % compressLevel)
self.compressLevel = compressLevel
def getExtensionString(self):
"""
Returns the WebSocket extension configuration string as sent to the server.
:returns: str -- PMCE configuration string.
"""
pmceString = self.EXTENSION_NAME
if self.offer.requestMaxCompressLevel != 0:
pmceString += "; server_max_compress_level=%d" % self.offer.requestMaxCompressLevel
if self.requestMaxCompressLevel != 0:
pmceString += "; client_max_compress_level=%d" % self.requestMaxCompressLevel
return pmceString
def __json__(self):
"""
Returns a JSON serializable object representation.
:returns: object -- JSON serializable representation.
"""
return {'extension': self.EXTENSION_NAME,
'offer': self.offer.__json__(),
'requestMaxCompressLevel': self.requestMaxCompressLevel,
'compressLevel': self.compressLevel}
def __repr__(self):
"""
Returns Python object representation that can be eval'ed to reconstruct the object.
:returns: str -- Python string representation.
"""
return "PerMessageBzip2Accept(offer = %s, requestMaxCompressLevel = %s, compressLevel = %s)" % (self.offer.__repr__(), self.requestMaxCompressLevel, self.compressLevel)
class PerMessageBzip2Response(PerMessageCompressResponse, PerMessageBzip2Mixin):
"""
Set of parameters for `permessage-bzip2` responded by server.
"""
@classmethod
def parse(cls, params):
"""
Parses a WebSocket extension response for `permessage-bzip2` provided by a server to a client.
:param params: Output from :func:`autobahn.websocket.WebSocketProtocol._parseExtensionsHeader`.
:type params: list
:returns: object -- A new instance of :class:`autobahn.compress.PerMessageBzip2Response`.
"""
client_max_compress_level = 0
server_max_compress_level = 0
for p in params:
if len(params[p]) > 1:
raise Exception("multiple occurrence of extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
val = params[p][0]
if p == 'client_max_compress_level':
try:
val = int(val)
except:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
if val not in PerMessageBzip2Mixin.COMPRESS_LEVEL_PERMISSIBLE_VALUES:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
else:
client_max_compress_level = val
elif p == 'server_max_compress_level':
try:
val = int(val)
except:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
if val not in PerMessageBzip2Mixin.COMPRESS_LEVEL_PERMISSIBLE_VALUES:
raise Exception("illegal extension parameter value '%s' for parameter '%s' of extension '%s'" % (val, p, cls.EXTENSION_NAME))
else:
server_max_compress_level = val
else:
raise Exception("illegal extension parameter '%s' for extension '%s'" % (p, cls.EXTENSION_NAME))
response = cls(client_max_compress_level,
server_max_compress_level)
return response
def __init__(self,
client_max_compress_level,
server_max_compress_level):
self.client_max_compress_level = client_max_compress_level
self.server_max_compress_level = server_max_compress_level
def __json__(self):
"""
Returns a JSON serializable object representation.
:returns: object -- JSON serializable representation.
"""
return {'extension': self.EXTENSION_NAME,
'client_max_compress_level': self.client_max_compress_level,
'server_max_compress_level': self.server_max_compress_level}
def __repr__(self):
"""
Returns Python object representation that can be eval'ed to reconstruct the object.
:returns: str -- Python string representation.
"""
return "PerMessageBzip2Response(client_max_compress_level = %s, server_max_compress_level = %s)" % (self.client_max_compress_level, self.server_max_compress_level)
class PerMessageBzip2ResponseAccept(PerMessageCompressResponseAccept, PerMessageBzip2Mixin):
"""
Set of parameters with which to accept an `permessage-bzip2` response
from a server by a client.
"""
def __init__(self,
response,
compressLevel=None):
"""
Constructor.
:param response: The response being accepted.
:type response: Instance of :class:`autobahn.compress.PerMessageBzip2Response`.
:param compressLevel: Override client ("client-to-server direction") compress level (this must be compatible with response).
:type compressLevel: int
"""
if not isinstance(response, PerMessageBzip2Response):
raise Exception("invalid type %s for response" % type(response))
self.response = response
if compressLevel is not None:
if compressLevel not in self.WINDOW_SIZE_PERMISSIBLE_VALUES:
raise Exception("invalid value %s for compressLevel - permissible values %s" % (compressLevel, self.COMPRESS_LEVEL_PERMISSIBLE_VALUES))
if response.client_max_compress_level != 0 and compressLevel > response.client_max_compress_level:
raise Exception("invalid value %s for compressLevel - server requested lower maximum value" % compressLevel)
self.compressLevel = compressLevel
def __json__(self):
"""
Returns a JSON serializable object representation.
:returns: object -- JSON serializable representation.
"""
return {'extension': self.EXTENSION_NAME,
'response': self.response.__json__(),
'compressLevel': self.compressLevel}
def __repr__(self):
"""
Returns Python object representation that can be eval'ed to reconstruct the object.
:returns: str -- Python string representation.
"""
return "PerMessageBzip2ResponseAccept(response = %s, compressLevel = %s)" % (self.response.__repr__(), self.compressLevel)
class PerMessageBzip2(PerMessageCompress, PerMessageBzip2Mixin):
"""
`permessage-bzip2` WebSocket extension processor.
"""
DEFAULT_COMPRESS_LEVEL = 9
@classmethod
def createFromResponseAccept(cls, isServer, accept):
pmce = cls(isServer,
accept.response.server_max_compress_level,
accept.compressLevel if accept.compressLevel is not None else accept.response.client_max_compress_level)
return pmce
@classmethod
def createFromOfferAccept(cls, isServer, accept):
pmce = cls(isServer,
accept.compressLevel if accept.compressLevel is not None else accept.offer.requestMaxCompressLevel,
accept.requestMaxCompressLevel)
return pmce
def __init__(self,
isServer,
server_max_compress_level,
client_max_compress_level):
self._isServer = isServer
self._compressor = None
self._decompressor = None
self.server_max_compress_level = server_max_compress_level if server_max_compress_level != 0 else self.DEFAULT_COMPRESS_LEVEL
self.client_max_compress_level = client_max_compress_level if client_max_compress_level != 0 else self.DEFAULT_COMPRESS_LEVEL
def __json__(self):
return {'extension': self.EXTENSION_NAME,
'isServer': self._isServer,
'server_max_compress_level': self.server_max_compress_level,
'client_max_compress_level': self.client_max_compress_level}
def __repr__(self):
return "PerMessageBzip2(isServer = %s, server_max_compress_level = %s, client_max_compress_level = %s)" % (self._isServer, self.server_max_compress_level, self.client_max_compress_level)
def startCompressMessage(self):
if self._isServer:
if self._compressor is None:
self._compressor = bz2.BZ2Compressor(self.server_max_compress_level)
else:
if self._compressor is None:
self._compressor = bz2.BZ2Compressor(self.client_max_compress_level)
def compressMessageData(self, data):
return self._compressor.compress(data)
def endCompressMessage(self):
data = self._compressor.flush()
# there seems to be no "flush without close stream", and after
# full flush, compressor must not be reused
self._compressor = None
return data
def startDecompressMessage(self):
if self._decompressor is None:
self._decompressor = bz2.BZ2Decompressor()
def decompressMessageData(self, data):
return self._decompressor.decompress(data)
def endDecompressMessage(self):
self._decompressor = None