Class: Lancat::Sender

Inherits:
Object
  • Object
show all
Defined in:
lib/lancat/sender.rb

Instance Method Summary collapse

Constructor Details

#initialize(verbose, timeout, input) ⇒ Sender

Returns a new instance of Sender.



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# File 'lib/lancat/sender.rb', line 6

def initialize(verbose, timeout, input)
  @verbose = verbose
  @timeout = timeout
  @input = input
end

Instance Method Details

#start ⇒ Object 



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# File 'lib/lancat/sender.rb', line 12

def start
  server = TCPServer.new(0)
  begin
    _, port, _, _ = server.addr(:numeric)

    STDERR.puts "Listening on port #{port}..." if @verbose

    # keep broadcasting packet indicating our IP/port, stop after timeout
    # or after a connection arrives
    client = nil
    multicast_sock = UDPSocket.new(Socket::AF_INET)
    begin
      multicast_sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_MULTICAST_LOOP, [1].pack('i'))
      multicast_sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_TTL, [1].pack('i'))

      msg = [port].pack('S>')

      for i in 1..@timeout
        STDERR.puts "Broadcast attempt #{i}..." if @verbose
        multicast_sock.send(msg, 0, MULTICAST_ADDR, MULTICAST_PORT)
        sleep 1

        begin
          client = server.accept_nonblock
          break if not client.nil?
        rescue IO::WaitReadable
          # ignore
        end
      end
    ensure
      multicast_sock.close
    end

    abort 'lancat: Timeout' if client.nil?

    _, _, _, remote = client.peeraddr(:numeric)
    STDERR.puts "Connection from #{remote}, writing data..." if @verbose

    loop do
      begin
        data = STDIN.readpartial(4096)
        client.write(data)
      rescue EOFError
        break
      end
    end
  ensure
    server.close
  end

  STDERR.puts 'Transfer complete.' if @verbose
end