Package dns :: Module rrset |
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# Source Code for Module dns.rrset

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     15
     16  """DNS RRsets (an RRset is a named rdataset)"""
     17
     18  import dns.name
     19  import dns.rdataset
     20  import dns.rdataclass
     21  import dns.renderer
     22
     23 -class RRset(dns.rdataset.Rdataset):
     24      """A DNS RRset (named rdataset).
     25
     26      RRset inherits from Rdataset, and RRsets can be treated as
     27      Rdatasets in most cases.  There are, however, a few notable
     28      exceptions.  RRsets have different to_wire() and to_text() method
     29      arguments, reflecting the fact that RRsets always have an owner
     30      name.
     31      """
     32
     33      __slots__ = ['name', 'deleting']
     34
     35 -    def __init__(self, name, rdclass, rdtype, covers=dns.rdatatype.NONE,
     36                   deleting=None):
     37          """Create a new RRset."""
     38
     39          super(RRset, self).__init__(rdclass, rdtype, covers)
     40          self.name = name
     41          self.deleting = deleting
     42
     43 -    def _clone(self):
     44          obj = super(RRset, self)._clone()
     45          obj.name = self.name
     46          obj.deleting = self.deleting
     47          return obj
     48
     49 -    def __repr__(self):
     50          if self.covers == 0:
     51              ctext = ''
     52          else:
     53              ctext = '(' + dns.rdatatype.to_text(self.covers) + ')'
     54          if not self.deleting is None:
     55              dtext = ' delete=' + dns.rdataclass.to_text(self.deleting)
     56          else:
     57              dtext = ''
     58          return '<DNS ' + str(self.name) + ' ' + \
     59                 dns.rdataclass.to_text(self.rdclass) + ' ' + \
     60                 dns.rdatatype.to_text(self.rdtype) + ctext + dtext + ' RRset>'
     61
     62 -    def __str__(self):
     63          return self.to_text()
     64
     65 -    def __eq__(self, other):
     66          """Two RRsets are equal if they have the same name and the same
     67          rdataset
     68
     69          @rtype: bool"""
     70          if not isinstance(other, RRset):
     71              return False
     72          if self.name != other.name:
     73              return False
     74          return super(RRset, self).__eq__(other)
     75
     76 -    def match(self, name, rdclass, rdtype, covers, deleting=None):
     77          """Returns True if this rrset matches the specified class, type,
     78          covers, and deletion state."""
     79
     80          if not super(RRset, self).match(rdclass, rdtype, covers):
     81              return False
     82          if self.name != name or self.deleting != deleting:
     83              return False
     84          return True
     85
     86 -    def to_text(self, origin=None, relativize=True, **kw):
     87          """Convert the RRset into DNS master file format.
     88
     89          @see: L{dns.name.Name.choose_relativity} for more information
     90          on how I{origin} and I{relativize} determine the way names
     91          are emitted.
     92
     93          Any additional keyword arguments are passed on to the rdata
     94          to_text() method.
     95
     96          @param origin: The origin for relative names, or None.
     97          @type origin: dns.name.Name object
     98          @param relativize: True if names should names be relativized
     99          @type relativize: bool"""
    100
    101          return super(RRset, self).to_text(self.name, origin, relativize,
    102                                            self.deleting, **kw)
    103
    104 -    def to_wire(self, file, compress=None, origin=None, **kw):
    105          """Convert the RRset to wire format."""
    106
    107          return super(RRset, self).to_wire(self.name, file, compress, origin,
    108                                            self.deleting, **kw)
    109
    110 -    def to_rdataset(self):
    111          """Convert an RRset into an Rdataset.
    112
    113          @rtype: dns.rdataset.Rdataset object
    114          """
    115          return dns.rdataset.from_rdata_list(self.ttl, list(self))
    116
    117
    118 -def from_text_list(name, ttl, rdclass, rdtype, text_rdatas):
    119      """Create an RRset with the specified name, TTL, class, and type, and with
    120      the specified list of rdatas in text format.
    121
    122      @rtype: dns.rrset.RRset object
    123      """
    124
    125      if isinstance(name, (str, unicode)):
    126          name = dns.name.from_text(name, None)
    127      if isinstance(rdclass, (str, unicode)):
    128          rdclass = dns.rdataclass.from_text(rdclass)
    129      if isinstance(rdtype, (str, unicode)):
    130          rdtype = dns.rdatatype.from_text(rdtype)
    131      r = RRset(name, rdclass, rdtype)
    132      r.update_ttl(ttl)
    133      for t in text_rdatas:
    134          rd = dns.rdata.from_text(r.rdclass, r.rdtype, t)
    135          r.add(rd)
    136      return r
    137
    138 -def from_text(name, ttl, rdclass, rdtype, *text_rdatas):
    139      """Create an RRset with the specified name, TTL, class, and type and with
    140      the specified rdatas in text format.
    141
    142      @rtype: dns.rrset.RRset object
    143      """
    144
    145      return from_text_list(name, ttl, rdclass, rdtype, text_rdatas)
    146
    147 -def from_rdata_list(name, ttl, rdatas):
    148      """Create an RRset with the specified name and TTL, and with
    149      the specified list of rdata objects.
    150
    151      @rtype: dns.rrset.RRset object
    152      """
    153
    154      if isinstance(name, (str, unicode)):
    155          name = dns.name.from_text(name, None)
    156
    157      if len(rdatas) == 0:
    158          raise ValueError("rdata list must not be empty")
    159      r = None
    160      for rd in rdatas:
    161          if r is None:
    162              r = RRset(name, rd.rdclass, rd.rdtype)
    163              r.update_ttl(ttl)
    164              first_time = False
    165          r.add(rd)
    166      return r
    167
    168 -def from_rdata(name, ttl, *rdatas):
    169      """Create an RRset with the specified name and TTL, and with
    170      the specified rdata objects.
    171
    172      @rtype: dns.rrset.RRset object
    173      """
    174
    175      return from_rdata_list(name, ttl, rdatas)
    176