Source Code for Module dns.namedict

  1  # Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license 
  2   
  3  # Copyright (C) 2003-2017 Nominum, Inc. 
  4  # Copyright (C) 2016 Coresec Systems AB 
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 21  # WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL CORESEC 
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 27   
 28  """DNS name dictionary""" 
 29   
 30  import collections 
 31  import dns.name 
 32  from ._compat import xrange 
 33   
 34   
 35 -class NameDict(collections.MutableMapping): 
 36      """A dictionary whose keys are dns.name.Name objects. 
 37   
 38      In addition to being like a regular Python dictionary, this 
 39      dictionary can also get the deepest match for a given key. 
 40      """ 
 41   
 42      __slots__ = ["max_depth", "max_depth_items", "__store"] 
 43   
 44 -    def __init__(self, *args, **kwargs): 
 45          super(NameDict, self).__init__() 
 46          self.__store = dict() 
 47          #: the maximum depth of the keys that have ever been added 
 48          self.max_depth = 0 
 49          #: the number of items of maximum depth 
 50          self.max_depth_items = 0 
 51          self.update(dict(*args, **kwargs)) 
 52   
 53 -    def __update_max_depth(self, key): 
 54          if len(key) == self.max_depth: 
 55              self.max_depth_items = self.max_depth_items + 1 
 56          elif len(key) > self.max_depth: 
 57              self.max_depth = len(key) 
 58              self.max_depth_items = 1 
 59   
 60 -    def __getitem__(self, key): 
 61          return self.__store[key] 
 62   
 63 -    def __setitem__(self, key, value): 
 64          if not isinstance(key, dns.name.Name): 
 65              raise ValueError('NameDict key must be a name') 
 66          self.__store[key] = value 
 67          self.__update_max_depth(key) 
 68   
 69 -    def __delitem__(self, key): 
 70          value = self.__store.pop(key) 
 71          if len(value) == self.max_depth: 
 72              self.max_depth_items = self.max_depth_items - 1 
 73          if self.max_depth_items == 0: 
 74              self.max_depth = 0 
 75              for k in self.__store: 
 76                  self.__update_max_depth(k) 
 77   
 78 -    def __iter__(self): 
 79          return iter(self.__store) 
 80   
 81 -    def __len__(self): 
 82          return len(self.__store) 
 83   
 84 -    def has_key(self, key): 
 85          return key in self.__store 
 86   
 87 -    def get_deepest_match(self, name): 
 88          """Find the deepest match to *fname* in the dictionary. 
 89   
 90          The deepest match is the longest name in the dictionary which is 
 91          a superdomain of *name*.  Note that *superdomain* includes matching 
 92          *name* itself. 
 93   
 94          *name*, a ``dns.name.Name``, the name to find. 
 95   
 96          Returns a ``(key, value)`` where *key* is the deepest 
 97          ``dns.name.Name``, and *value* is the value associated with *key*. 
 98          """ 
 99   
100          depth = len(name) 
101          if depth > self.max_depth: 
102              depth = self.max_depth 
103          for i in xrange(-depth, 0): 
104              n = dns.name.Name(name[i:]) 
105              if n in self: 
106                  return (n, self[n]) 
107          v = self[dns.name.empty] 
108          return (dns.name.empty, v) 
109