# Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
# Copyright (C) 2016 Coresec Systems AB
#
# 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.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND CORESEC SYSTEMS AB DISCLAIMS ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL CORESEC
# SYSTEMS AB 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 name dictionary"""
import collections
import dns.name
from ._compat import xrange
class NameDict(collections.MutableMapping):
"""A dictionary whose keys are dns.name.Name objects.
@ivar max_depth: the maximum depth of the keys that have ever been
added to the dictionary.
@type max_depth: int
@ivar max_depth_items: the number of items of maximum depth
@type max_depth_items: int
"""
__slots__ = ["max_depth", "max_depth_items", "__store"]
def __init__(self, *args, **kwargs):
self.__store = dict()
self.max_depth = 0
self.max_depth_items = 0
self.update(dict(*args, **kwargs))
def __update_max_depth(self, key):
if len(key) == self.max_depth:
self.max_depth_items = self.max_depth_items + 1
elif len(key) > self.max_depth:
self.max_depth = len(key)
self.max_depth_items = 1
def __getitem__(self, key):
return self.__store[key]
def __setitem__(self, key, value):
if not isinstance(key, dns.name.Name):
raise ValueError('NameDict key must be a name')
self.__store[key] = value
self.__update_max_depth(key)
def __delitem__(self, key):
value = self.__store.pop(key)
if len(value) == self.max_depth:
self.max_depth_items = self.max_depth_items - 1
if self.max_depth_items == 0:
self.max_depth = 0
for k in self.__store:
self.__update_max_depth(k)
def __iter__(self):
return iter(self.__store)
def __len__(self):
return len(self.__store)
def has_key(self, key):
return key in self.__store
def get_deepest_match(self, name):
"""Find the deepest match to I{name} in the dictionary.
The deepest match is the longest name in the dictionary which is
a superdomain of I{name}.
@param name: the name
@type name: dns.name.Name object
@rtype: (key, value) tuple
"""
depth = len(name)
if depth > self.max_depth:
depth = self.max_depth
for i in xrange(-depth, 0):
n = dns.name.Name(name[i:])
if n in self:
return (n, self[n])
v = self[dns.name.empty]
return (dns.name.empty, v)
