AlkantarClanX12
Current Path : /lib64/python2.7/site-packages/dns/ |
Current File : //lib64/python2.7/site-packages/dns/wiredata.py |
# 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 # 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(str): def __getslice__(self, i, j): return j _unspecified_bound = _SliceUnspecifiedBound('')[1:] class WireData(str): # WireData is a string with stricter slicing def __getitem__(self, key): try: return WireData(super(WireData, self).__getitem__(key)) except IndexError: raise dns.exception.FormError def __getslice__(self, i, j): try: if j == _unspecified_bound: # handle the case where the right bound is unspecified j = len(self) if i < 0 or j < 0: raise dns.exception.FormError # If it's not an empty slice, access left and right bounds # to make sure they're valid if i != j: super(WireData, self).__getitem__(i) super(WireData, self).__getitem__(j - 1) return WireData(super(WireData, self).__getslice__(i, j)) except IndexError: raise dns.exception.FormError def __iter__(self): i = 0 while 1: try: yield self[i] i += 1 except dns.exception.FormError: raise StopIteration def unwrap(self): return str(self) def maybe_wrap(wire): if not isinstance(wire, WireData): return WireData(wire) else: return wire