mirror of https://github.com/morpheus65535/bazarr
104 lines
3.6 KiB
Python
104 lines
3.6 KiB
Python
|
# Copyright (C) 2011 Nominum, Inc.
|
||
|
|
#
|
||
|
|
# Permission to use, copy, modify, and distribute this software and its
|
||
|
|
# documentation for any purpose with or without fee is hereby granted,
|
||
|
|
# provided that the above copyright notice and this permission notice
|
||
|
|
# appear in all copies.
|
||
|
|
#
|
||
|
|
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
|
||
|
|
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
||
|
|
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
|
||
|
|
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
||
|
|
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
||
|
|
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
|
||
|
|
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||
|
|
|
||
|
|
"""DNS Wire Data Helper"""
|
||
|
|
|
||
|
|
import sys
|
||
|
|
|
||
|
|
import dns.exception
|
||
|
|
from ._compat import binary_type, string_types
|
||
|
|
|
||
|
|
# Figure out what constant python passes for an unspecified slice bound.
|
||
|
|
# It's supposed to be sys.maxint, yet on 64-bit windows sys.maxint is 2^31 - 1
|
||
|
|
# but Python uses 2^63 - 1 as the constant. Rather than making pointless
|
||
|
|
# extra comparisons, duplicating code, or weakening WireData, we just figure
|
||
|
|
# out what constant Python will use.
|
||
|
|
|
||
|
|
|
||
|
|
class _SliceUnspecifiedBound(binary_type):
|
||
|
|
|
||
|
|
def __getitem__(self, key):
|
||
|
|
return key.stop
|
||
|
|
|
||
|
|
if sys.version_info < (3,):
|
||
|
|
def __getslice__(self, i, j): # pylint: disable=getslice-method
|
||
|
|
return self.__getitem__(slice(i, j))
|
||
|
|
|
||
|
|
_unspecified_bound = _SliceUnspecifiedBound()[1:]
|
||
|
|
|
||
|
|
|
||
|
|
class WireData(binary_type):
|
||
|
|
# WireData is a string with stricter slicing
|
||
|
|
|
||
|
|
def __getitem__(self, key):
|
||
|
|
try:
|
||
|
|
if isinstance(key, slice):
|
||
|
|
# make sure we are not going outside of valid ranges,
|
||
|
|
# do stricter control of boundaries than python does
|
||
|
|
# by default
|
||
|
|
start = key.start
|
||
|
|
stop = key.stop
|
||
|
|
|
||
|
|
if sys.version_info < (3,):
|
||
|
|
if stop == _unspecified_bound:
|
||
|
|
# handle the case where the right bound is unspecified
|
||
|
|
stop = len(self)
|
||
|
|
|
||
|
|
if start < 0 or stop < 0:
|
||
|
|
raise dns.exception.FormError
|
||
|
|
# If it's not an empty slice, access left and right bounds
|
||
|
|
# to make sure they're valid
|
||
|
|
if start != stop:
|
||
|
|
super(WireData, self).__getitem__(start)
|
||
|
|
super(WireData, self).__getitem__(stop - 1)
|
||
|
|
else:
|
||
|
|
for index in (start, stop):
|
||
|
|
if index is None:
|
||
|
|
continue
|
||
|
|
elif abs(index) > len(self):
|
||
|
|
raise dns.exception.FormError
|
||
|
|
|
||
|
|
return WireData(super(WireData, self).__getitem__(
|
||
|
|
slice(start, stop)))
|
||
|
|
return bytearray(self.unwrap())[key]
|
||
|
|
except IndexError:
|
||
|
|
raise dns.exception.FormError
|
||
|
|
|
||
|
|
if sys.version_info < (3,):
|
||
|
|
def __getslice__(self, i, j): # pylint: disable=getslice-method
|
||
|
|
return self.__getitem__(slice(i, j))
|
||
|
|
|
||
|
|
def __iter__(self):
|
||
|
|
i = 0
|
||
|
|
while 1:
|
||
|
|
try:
|
||
|
|
yield self[i]
|
||
|
|
i += 1
|
||
|
|
except dns.exception.FormError:
|
||
|
|
raise StopIteration
|
||
|
|
|
||
|
|
def unwrap(self):
|
||
|
|
return binary_type(self)
|
||
|
|
|
||
|
|
|
||
|
|
def maybe_wrap(wire):
|
||
|
|
if isinstance(wire, WireData):
|
||
|
|
return wire
|
||
|
|
elif isinstance(wire, binary_type):
|
||
|
|
return WireData(wire)
|
||
|
|
elif isinstance(wire, string_types):
|
||
|
|
return WireData(wire.encode())
|
||
|
|
raise ValueError("unhandled type %s" % type(wire))
|