# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2003-2017 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"""
# pylint seems to be confused about this one!
from collections.abc import MutableMapping # pylint: disable=no-name-in-module
import dns.name
class NameDict(MutableMapping):
"""A dictionary whose keys are dns.name.Name objects.
In addition to being like a regular Python dictionary, this
dictionary can also get the deepest match for a given key.
"""
__slots__ = ["max_depth", "max_depth_items", "__store"]
def __init__(self, *args, **kwargs):
super().__init__()
self.__store = dict()
#: the maximum depth of the keys that have ever been added
self.max_depth = 0
#: the number of items of maximum depth
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):
self.__store.pop(key)
if len(key) == 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 *name* in the dictionary.
The deepest match is the longest name in the dictionary which is
a superdomain of *name*. Note that *superdomain* includes matching
*name* itself.
*name*, a ``dns.name.Name``, the name to find.
Returns a ``(key, value)`` where *key* is the deepest
``dns.name.Name``, and *value* is the value associated with *key*.
"""
depth = len(name)
if depth > self.max_depth:
depth = self.max_depth
for i in range(-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)
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