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# Copyright (C) 2003-2007, 2009-2011 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 RRsets (an RRset is a named rdataset)"""
import dns.name
import dns.rdataset
import dns.rdataclass
import dns.renderer
from ._compat import string_types
class RRset(dns.rdataset.Rdataset):
"""A DNS RRset (named rdataset).
RRset inherits from Rdataset, and RRsets can be treated as
Rdatasets in most cases. There are, however, a few notable
exceptions. RRsets have different to_wire() and to_text() method
arguments, reflecting the fact that RRsets always have an owner
name.
"""
__slots__ = ['name', 'deleting']
def __init__(self, name, rdclass, rdtype, covers=dns.rdatatype.NONE,
deleting=None):
"""Create a new RRset."""
super(RRset, self).__init__(rdclass, rdtype, covers)
self.name = name
self.deleting = deleting
def _clone(self):
obj = super(RRset, self)._clone()
obj.name = self.name
obj.deleting = self.deleting
return obj
def __repr__(self):
if self.covers == 0:
ctext = ''
else:
ctext = '(' + dns.rdatatype.to_text(self.covers) + ')'
if self.deleting is not None:
dtext = ' delete=' + dns.rdataclass.to_text(self.deleting)
else:
dtext = ''
return '<DNS ' + str(self.name) + ' ' + \
dns.rdataclass.to_text(self.rdclass) + ' ' + \
dns.rdatatype.to_text(self.rdtype) + ctext + dtext + ' RRset>'
def __str__(self):
return self.to_text()
def __eq__(self, other):
"""Two RRsets are equal if they have the same name and the same
rdataset
@rtype: bool"""
if not isinstance(other, RRset):
return False
if self.name != other.name:
return False
return super(RRset, self).__eq__(other)
def match(self, name, rdclass, rdtype, covers, deleting=None):
"""Returns True if this rrset matches the specified class, type,
covers, and deletion state."""
if not super(RRset, self).match(rdclass, rdtype, covers):
return False
if self.name != name or self.deleting != deleting:
return False
return True
def to_text(self, origin=None, relativize=True, **kw):
"""Convert the RRset into DNS master file format.
@see: L{dns.name.Name.choose_relativity} for more information
on how I{origin} and I{relativize} determine the way names
are emitted.
Any additional keyword arguments are passed on to the rdata
to_text() method.
@param origin: The origin for relative names, or None.
@type origin: dns.name.Name object
@param relativize: True if names should names be relativized
@type relativize: bool"""
return super(RRset, self).to_text(self.name, origin, relativize,
self.deleting, **kw)
def to_wire(self, file, compress=None, origin=None, **kw):
"""Convert the RRset to wire format."""
return super(RRset, self).to_wire(self.name, file, compress, origin,
self.deleting, **kw)
def to_rdataset(self):
"""Convert an RRset into an Rdataset.
@rtype: dns.rdataset.Rdataset object
"""
return dns.rdataset.from_rdata_list(self.ttl, list(self))
def from_text_list(name, ttl, rdclass, rdtype, text_rdatas,
idna_codec=None):
"""Create an RRset with the specified name, TTL, class, and type, and with
the specified list of rdatas in text format.
@rtype: dns.rrset.RRset object
"""
if isinstance(name, string_types):
name = dns.name.from_text(name, None, idna_codec=idna_codec)
if isinstance(rdclass, string_types):
rdclass = dns.rdataclass.from_text(rdclass)
if isinstance(rdtype, string_types):
rdtype = dns.rdatatype.from_text(rdtype)
r = RRset(name, rdclass, rdtype)
r.update_ttl(ttl)
for t in text_rdatas:
rd = dns.rdata.from_text(r.rdclass, r.rdtype, t)
r.add(rd)
return r
def from_text(name, ttl, rdclass, rdtype, *text_rdatas):
"""Create an RRset with the specified name, TTL, class, and type and with
the specified rdatas in text format.
@rtype: dns.rrset.RRset object
"""
return from_text_list(name, ttl, rdclass, rdtype, text_rdatas)
def from_rdata_list(name, ttl, rdatas, idna_codec=None):
"""Create an RRset with the specified name and TTL, and with
the specified list of rdata objects.
@rtype: dns.rrset.RRset object
"""
if isinstance(name, string_types):
name = dns.name.from_text(name, None, idna_codec=idna_codec)
if len(rdatas) == 0:
raise ValueError("rdata list must not be empty")
r = None
for rd in rdatas:
if r is None:
r = RRset(name, rd.rdclass, rd.rdtype)
r.update_ttl(ttl)
r.add(rd)
return r
def from_rdata(name, ttl, *rdatas):
"""Create an RRset with the specified name and TTL, and with
the specified rdata objects.
@rtype: dns.rrset.RRset object
"""
return from_rdata_list(name, ttl, rdatas)
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