virtualModem/src/net/hoo2/auth/vmodem/Echo.java

package net.hoo2.auth.vmodem;

class Echo {
   static final int ECHO_DURATION_DEFAULT = 240;
   static final int ECHO_BUFFER_SIZE      = 256;
   static final String ECHO_BEGIN         = "PSTART";
   static final String ECHO_END           = "PSTOP";

   private Com          com_;
   private Log          log_;
   private Transaction  transaction_;
   private int          duration_;
   private byte[]       code_;
   
   Echo (Com com, Log log, byte[] code, int duration) {
      com_        = com;
      log_        = log;
      duration_   = duration;
      transaction_= new Transaction(null, new byte[ECHO_BUFFER_SIZE]);
      code_       = code;
   }

   void caption (byte[] code) {
      String line;

      line = "Running ECHO with: " + new String(code);
      log_.write(line, true);

      transaction_ = com_.request (transaction_, null, null, null, false);
      line = new String(transaction_.getResponse());
      log_.out(line);
   }

   void run () {
      long start;
      long now;
      String line;

      start = System.currentTimeMillis();
      do {
         transaction_ = com_.request(transaction_, code_, ECHO_BEGIN.getBytes(), ECHO_END.getBytes(), false);
         line = new String(transaction_.code) + ": "
              + new String(transaction_.getResponse())
              + " Tr= " + (transaction_.arrival - transaction_.departure) + " [msec]";
         log_.write(line);
         now = System.currentTimeMillis();
      } while (now - start < duration_*1000);
   }
   
}