Package dns :: Module wiredata
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Source Code for Module dns.wiredata

 1  # Copyright (C) 2011 Nominum, Inc. 
 2  # 
 3  # Permission to use, copy, modify, and distribute this software and its 
 4  # documentation for any purpose with or without fee is hereby granted, 
 5  # provided that the above copyright notice and this permission notice 
 6  # appear in all copies. 
 7  # 
 8  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES 
 9  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
10  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR 
11  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
12  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
13  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 
14  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
15   
16  """DNS Wire Data Helper""" 
17   
18  import sys 
19   
20  import dns.exception 
21   
22 -class WireData(str):
23 # WireData is a string with stricter slicing
24 - def __getitem__(self, key):
25 try: 26 return WireData(super(WireData, self).__getitem__(key)) 27 except IndexError: 28 raise dns.exception.FormError
29 - def __getslice__(self, i, j):
30 try: 31 if j == sys.maxint: 32 # handle the case where the right bound is unspecified 33 j = len(self) 34 if i < 0 or j < 0: 35 raise dns.exception.FormError 36 # If it's not an empty slice, access left and right bounds 37 # to make sure they're valid 38 if i != j: 39 super(WireData, self).__getitem__(i) 40 super(WireData, self).__getitem__(j - 1) 41 return WireData(super(WireData, self).__getslice__(i, j)) 42 except IndexError: 43 raise dns.exception.FormError
44 - def __iter__(self):
45 i = 0 46 while 1: 47 try: 48 yield self[i] 49 i += 1 50 except dns.exception.FormError: 51 raise StopIteration
52 - def unwrap(self):
53 return str(self)
54
55 -def maybe_wrap(wire):
56 if not isinstance(wire, WireData): 57 return WireData(wire) 58 else: 59 return wire
60