Class: Dnsruby::RR::LOC

Inherits:
Dnsruby::RR show all
Defined in:
lib/dnsruby/resource/LOC.rb

Overview

Class for DNS Location (LOC) resource records. See RFC 1876 for details.

Constant Summary collapse

ClassValue =

:nodoc: all

nil
TypeValue =

:nodoc: all

Types::LOC
POWEROFTEN =

Powers of 10 from 0 to 9 (used to speed up calculations).

[1, 10, 100, 1_000, 10_000, 100_000, 1_000_000, 10_000_000, 100_000_000, 1_000_000_000]
REFERENCE_ALT =

Reference altitude in centimeters (see RFC 1876).

100_000 * 100
REFERENCE_LATLON =

Reference lat/lon (see RFC 1876).

2**31
CONV_SEC =

Conversions to/from thousandths of a degree.

1000
CONV_MIN = 
60 * CONV_SEC
CONV_DEG = 
60 * CONV_MIN
DEFAULT_MIN =

Defaults (from RFC 1876, Section 3).

0
DEFAULT_SEC = 
0
DEFAULT_SIZE = 
1
DEFAULT_HORIZ_PRE = 
10_000
DEFAULT_VERT_PRE = 
10

Constants inherited from Dnsruby::RR

ClassInsensitiveTypes

Instance Attribute Summary collapse

Attributes inherited from Dnsruby::RR

#klass, #name, #rdata, #ttl, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Dnsruby::RR

#<=>, #==, #clone, create, #eql?, find_class, get_class, get_num, #hash, implemented_rrs, #init_defaults, new_from_data, new_from_hash, new_from_string, #rdlength, #sameRRset, #to_s

Instance Attribute Details

#altitude ⇒ Object

The altitude of the center of the sphere described by the size method, in centimeters, from a base of 100,000m below the WGS 84 reference spheroid used by GPS.



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# File 'lib/dnsruby/resource/LOC.rb', line 48

def altitude
  @altitude
end

#horiz_pre ⇒ Object

The horizontal precision of the data, in centimeters.



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# File 'lib/dnsruby/resource/LOC.rb', line 33

def horiz_pre
  @horiz_pre
end

#latitude ⇒ Object

The latitude of the center of the sphere described by the size method, in thousandths of a second of arc. 2**31 represents the equator; numbers above that are north latitude.



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# File 'lib/dnsruby/resource/LOC.rb', line 39

def latitude
  @latitude
end

#longitude ⇒ Object

The longitude of the center of the sphere described by the size method, in thousandths of a second of arc. 2**31 represents the prime meridian; numbers above that are east longitude.



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# File 'lib/dnsruby/resource/LOC.rb', line 44

def longitude
  @longitude
end

#size ⇒ Object

The diameter of a sphere enclosing the described entity, in centimeters.



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# File 'lib/dnsruby/resource/LOC.rb', line 31

def size
  @size
end

#version ⇒ Object

The version number of the representation; programs should always check this. Dnsruby currently supports only version 0.



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# File 'lib/dnsruby/resource/LOC.rb', line 26

def version
  @version
end

#vert_pre ⇒ Object

The vertical precision of the data, in centimeters.



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# File 'lib/dnsruby/resource/LOC.rb', line 35

def vert_pre
  @vert_pre
end

Class Method Details

.decode_rdata(msg) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/LOC.rb', line 227

def self.decode_rdata(msg) #:nodoc: all
  version, = msg.get_unpack("C")
  if (version == 0)
    size, horiz_pre, vert_pre, latitude, longitude, altitude = msg.get_unpack('CCCNNN')
    size = precsize_ntoval(size)
    horiz_pre = precsize_ntoval(horiz_pre)
    vert_pre = precsize_ntoval(vert_pre)
    return self.new([version, size, horiz_pre, vert_pre, latitude, longitude, altitude])
  end
end

.precsize_ntoval(prec) ⇒ Object 



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# File 'lib/dnsruby/resource/LOC.rb', line 247

def self.precsize_ntoval(prec)
  mantissa = ((prec >> 4) & 0x0f) % 10;
  exponent = (prec & 0x0f) % 10;
  return mantissa * POWEROFTEN[exponent];
end

Instance Method Details

#dms2latlon(deg, min, sec, hem) ⇒ Object 



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# File 'lib/dnsruby/resource/LOC.rb', line 89

def dms2latlon(deg, min, sec, hem)
  retval=0

  retval = (deg * CONV_DEG) + (min * CONV_MIN) + (sec * CONV_SEC).round;
  retval = -retval if ((hem != nil) && ((hem == "S") || (hem == "W")));
  retval += REFERENCE_LATLON;
  return retval;
end

#encode_rdata(msg, canonical = false) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/LOC.rb', line 238

def encode_rdata(msg, canonical=false) #:nodoc: all
  msg.put_pack('C', @version)
  if (@version == 0)
    msg.put_pack('CCCNNN', precsize_valton(@size),
    precsize_valton(@horiz_pre), precsize_valton(@vert_pre),
    @latitude, @longitude, @altitude)
  end
end

#from_data(data) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/LOC.rb', line 123

def from_data(data) #:nodoc: all
  @version, @size, @horiz_pre, @vert_pre, @latitude, @longitude, @altitude = data
end

#from_hash(hash) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/LOC.rb', line 181

def from_hash(hash) #:nodoc: all
  super(hash)
  if (@size == nil)
    @size = DEFAULT_SIZE * 100
  end
  if @horiz_pre == nil
    @horiz_pre = DEFAULT_HORIZ_PRE * 100
  end
  if @vert_pre == nil
    @vert_pre = DEFAULT_VERT_PRE * 100
  end
end

#from_string(string) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/LOC.rb', line 127

def from_string(string) #:nodoc: all
  if (string &&
      string =~ /^ (\d+) \s+		# deg lat
   ((\d+) \s+)?		# min lat
   (([\d.]+) \s+)?	# sec lat
   (N|S) \s+		# hem lat
   (\d+) \s+		# deg lon
   ((\d+) \s+)?		# min lon
   (([\d.]+) \s+)?	# sec lon
   (E|W) \s+		# hem lon
   (-?[\d.]+) m? 	# altitude
   (\s+ ([\d.]+) m?)?	# size
   (\s+ ([\d.]+) m?)?	# horiz precision
   (\s+ ([\d.]+) m?)? 	# vert precision
    /ix)  #

    size = DEFAULT_SIZE

    #  What to do for other versions?
    version = 0;

    horiz_pre = DEFAULT_HORIZ_PRE
    vert_pre  = DEFAULT_VERT_PRE
    latdeg, latmin, latsec, lathem = $1.to_i, $3.to_i, $5.to_f, $6;
    londeg, lonmin, lonsec, lonhem = $7.to_i, $9.to_i, $11.to_f, $12
    alt = $13.to_i
    if ($15)
      size = $15.to_f
    end
    if ($17)
    horiz_pre = $17.to_f
    end
    if ($19)
      vert_pre = $19.to_f
    end

    latmin    = DEFAULT_MIN       unless latmin;
    latsec    = DEFAULT_SEC       unless latsec;
    lathem    = lathem.upcase;

    lonmin    = DEFAULT_MIN       unless lonmin;
    lonsec    = DEFAULT_SEC       unless lonsec;
    lonhem    = lonhem.upcase

    @version   = version;
    @size      = size * 100;
    @horiz_pre = horiz_pre * 100;
    @vert_pre  = vert_pre * 100;
    @latitude  = dms2latlon(latdeg, latmin, latsec, lathem);
    @longitude = dms2latlon(londeg, lonmin, lonsec, lonhem);
    @altitude  = alt * 100 + REFERENCE_ALT;
  end
end

#latlon ⇒ Object

Returns the latitude and longitude as floating-point degrees. Positive numbers represent north latitude or east longitude; negative numbers represent south latitude or west longitude.

lat, lon = rr.latlon
system("xearth", "-pos", "fixed #{lat} #{lon}")



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# File 'lib/dnsruby/resource/LOC.rb', line 105

def latlon
  retlat, retlon = nil

  if (@version == 0)
    retlat = latlon2deg(@latitude);
    retlon = latlon2deg(@longitude);
  end

  return retlat, retlon
end

#latlon2deg(rawmsec) ⇒ Object 



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# File 'lib/dnsruby/resource/LOC.rb', line 116

def latlon2deg(rawmsec)
  deg=0;

  deg = (rawmsec - reference_latlon) / CONV_DEG;
  return deg;
end

#latlon2dms(rawmsec, hems) ⇒ Object 



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# File 'lib/dnsruby/resource/LOC.rb', line 71

def latlon2dms(rawmsec, hems)
  #  Tried to use modulus here, but Perl dumped core if
  #  the value was >= 2**31.

  abs  = (rawmsec - REFERENCE_LATLON).abs;
  deg  = (abs / CONV_DEG).round;
  abs  -= deg * CONV_DEG;
  min  = (abs / CONV_MIN).round;
  abs -= min * CONV_MIN;
  sec  = (abs / CONV_SEC).round;  # $conv_sec
  abs -= sec * CONV_SEC;
  msec = abs;

  hem = hems[(rawmsec >= REFERENCE_LATLON ? 0 : 1), 1]

  return sprintf("%d %02d %02d.%03d %s", deg, min, sec, msec, hem);
end

#precsize_valton(val) ⇒ Object 



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# File 'lib/dnsruby/resource/LOC.rb', line 253

def precsize_valton(val)
  exponent = 0;
  while (val >= 10)
    val /= 10;
    exponent+=1
  end
  return (val.round << 4) | (exponent & 0x0f);
end

#rdata_to_string ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/LOC.rb', line 194

def rdata_to_string #:nodoc: all
  rdatastr=""

  if (defined?@version)
    if (@version == 0)
      lat       = @latitude;
      lon       = @longitude;
      altitude  = @altitude;
      size      = @size;
      horiz_pre = @horiz_pre;
      vert_pre  = @vert_pre;

      altitude   = (altitude - REFERENCE_ALT) / 100;
      size      /= 100;
      horiz_pre /= 100;
      vert_pre  /= 100;

      rdatastr = latlon2dms(lat, "NS") + " " +
      latlon2dms(lon, "EW") + " " +
      sprintf("%.2fm", altitude)  + " " +
      sprintf("%.2fm", size)      + " " +
      sprintf("%.2fm", horiz_pre) + " " +
      sprintf("%.2fm", vert_pre);
    else
      rdatastr = "; version " + @version + " not supported";
    end
  else
    rdatastr = '';
  end

  return rdatastr;
end