text: # Copyright (C) 2003-2005 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.
  
  import struct
  
  import dns.exception
  import dns.rdata
  import dns.name
  
  class SOA(dns.rdata.Rdata):
      """SOA record
  
      @ivar mname: the SOA MNAME (master name) field
      @type mname: dns.name.Name object
      @ivar rname: the SOA RNAME (responsible name) field
      @type rname: dns.name.Name object
      @ivar serial: The zone's serial number
      @type serial: int
      @ivar refresh: The zone's refresh value (in seconds)
      @type refresh: int
      @ivar retry: The zone's retry value (in seconds)
      @type retry: int
      @ivar expire: The zone's expiration value (in seconds)
      @type expire: int
      @ivar minimum: The zone's negative caching time (in seconds, called
      "minimum" for historical reasons)
      @type minimum: int
      @see: RFC 1035"""
  
      __slots__ = ['mname', 'rname', 'serial', 'refresh', 'retry', 'expire',
                   'minimum']
      
      def __init__(self, rdclass, rdtype, mname, rname, serial, refresh, retry,
                   expire, minimum):
          super(SOA, self).__init__(rdclass, rdtype)
          self.mname = mname
          self.rname = rname
          self.serial = serial
          self.refresh = refresh
          self.retry = retry
          self.expire = expire
          self.minimum = minimum
  
      def to_text(self, origin=None, relativize=True, **kw):
          mname = self.mname.choose_relativity(origin, relativize)
          rname = self.rname.choose_relativity(origin, relativize)
          return '%s %s %d %d %d %d %d' % (
              mname, rname, self.serial, self.refresh, self.retry,
              self.expire, self.minimum )
          
      def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
          mname = tok.get_name()
          rname = tok.get_name()
          mname = mname.choose_relativity(origin, relativize)
          rname = rname.choose_relativity(origin, relativize)
          serial = tok.get_uint32()
          refresh = tok.get_ttl()
          retry = tok.get_ttl()
          expire = tok.get_ttl()
          minimum = tok.get_ttl()
          tok.get_eol()
          return cls(rdclass, rdtype, mname, rname, serial, refresh, retry,
                     expire, minimum )
      
      from_text = classmethod(from_text)
  
      def to_wire(self, file, compress = None, origin = None):
          self.mname.to_wire(file, compress, origin)
          self.rname.to_wire(file, compress, origin)
          five_ints = struct.pack('!IIIII', self.serial, self.refresh,
                                  self.retry, self.expire, self.minimum)
          file.write(five_ints)
          
      def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
          (mname, cused) = dns.name.from_wire(wire[: current + rdlen], current)
          current += cused
          rdlen -= cused
          (rname, cused) = dns.name.from_wire(wire[: current + rdlen], current)
          current += cused
          rdlen -= cused
          if rdlen != 20:
              raise dns.exception.FormError
          five_ints = struct.unpack('!IIIII',
                                    wire[current : current + rdlen])
          if not origin is None:
              mname = mname.relativize(origin)
              rname = rname.relativize(origin)
          return cls(rdclass, rdtype, mname, rname,
                     five_ints[0], five_ints[1], five_ints[2], five_ints[3],
                     five_ints[4])
  
      from_wire = classmethod(from_wire)
  
      def choose_relativity(self, origin = None, relativize = True):
          self.mname = self.mname.choose_relativity(origin, relativize)
          self.rname = self.rname.choose_relativity(origin, relativize)
  
      def _cmp(self, other):
          v = cmp(self.mname, other.mname)
          if v == 0:
              v = cmp(self.rname, other.rname)
              if v == 0:
                  self_ints = struct.pack('!IIIII', self.serial, self.refresh,
                                          self.retry, self.expire, self.minimum)
                  other_ints = struct.pack('!IIIII', other.serial, other.refresh,
                                           other.retry, other.expire,
                                           other.minimum)
                  v = cmp(self_ints, other_ints)
          return v
  