Class: Nesser::Packer

Inherits:
Object
  • Object
show all
Defined in:
lib/nesser/packets/packer.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Packer

Returns a new instance of Packer.



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# File 'lib/nesser/packets/packer.rb', line 22

def initialize()
  @data = ''
  @segment_cache = {}
end

Instance Method Details

#get ⇒ Object 



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# File 'lib/nesser/packets/packer.rb', line 131

def get()
  return @data
end

#pack(format, *data) ⇒ Object 



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# File 'lib/nesser/packets/packer.rb', line 32

def pack(format, *data)
  @data += data.pack(format)
end

#pack_name(name, dry_run: false, compress: true) ⇒ Object 



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# File 'lib/nesser/packets/packer.rb', line 86

def pack_name(name, dry_run:false, compress:true)
  length = 0
  validate!(name)

  # `name` becomes nil at the end, unless there's a comma on the end, in
  # which case it's a 0-length string
  while name and name.length() > 0
    if compress && @segment_cache[name]
      # User a pointer if we've already done this
      if not dry_run
        @data += [0xc000 | @segment_cache[name]].pack("n")
      end

      # If we use break here, we get a bad NUL terminator
      return length + 2
    end

    # Log where we put this segment
    if not dry_run
      @segment_cache[name] = @data.length
    end

    # Get the next label
    segment, name = name.split(/\./, 2)

    # Encode it into the string
    if not dry_run
      @data += [segment.length(), segment].pack("Ca*")
    end
    length += 1 + segment.length()
  end

  # Always be null terminating
  if not dry_run
    @data += "\0"
  end
  length += 1

  return length
end