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

package net.hoo2.auth.vmodem;

import ithakimodem.*;

class Com {
   static final int SPEED_DEFAULT   = 9600;
   static final int TIMEOUT_DEFAULT = 2000;
   static final String URL_DEFAULT  = "ithaki";

   Com () {
      modem_   = new Modem();
      speed_   = SPEED_DEFAULT;
      timeout_ = TIMEOUT_DEFAULT;
      modem_.setSpeed(speed_);
      modem_.setTimeout(timeout_);
   }
   Com (int speed, int timeout) {
      modem_   = new Modem();
      speed_   = speed;
      timeout_ = timeout;
      modem_.setSpeed(speed_);
      modem_.setTimeout(timeout_);
   }
   
   // get/set
   int  timeout ()      { return timeout_; }
   void timeout (int t) { 
      timeout_ = t;
      modem_.setTimeout(timeout_);
   }
   
   int  speed () { return speed_;  }
   void speed (int speed) {
      speed_ = speed;
      modem_.setSpeed(speed_);
   }
   

   boolean open (String url) { return modem_.open(url); }
   boolean open ()           { return modem_.open(URL_DEFAULT); }
   boolean close()           { return modem_.close(); }


   Transaction request (Transaction data, boolean ask, byte[] delimiter) {
      int ch =0;
      int i =0;

      _clear (data.response);
      if (ask) {
         modem_.write(data.code);
         modem_.write((int)'\r');
         data.departure = System.currentTimeMillis() - (long)((8*(data.code.length+1))*(1000.0/speed_));
      }
      do {
         try {
            ch = modem_.read();
         }
         catch (Exception e) {
            System.out.println (e.getMessage());
         }
         if (i == 0)
            data.arrival = System.currentTimeMillis() - (long)(8*(1000.0/speed_));
         data.response [i++] = (byte)ch;
      } while (!_detect (data.response, "\r\n\n\n".getBytes())
            && !_detect (data.response, "NO CARRIER".getBytes())
            && !_detect (data.response, delimiter)
            && ch != -1);
      
      return data;
   }
   
   private boolean _detect (byte[] response, byte[] pattern) {
      if (pattern != null) {
         for (int i =0 ; i<response.length - pattern.length ; ++i) {
            boolean detected = true;
            for (int j=0 ; j<pattern.length ; ++j) {
               if (response[i+j] != pattern[j]) {
                  detected = false;
                  break;
               }
            }
            if (detected)
               return true;
         }
      }
      return false;
   }

   private void _clear (byte[] buffer) {
      for (int i=0 ; i<buffer.length ; ++i)
         buffer[i] = 0;
   }

   private Modem modem_;
   private int   speed_;
   private int   timeout_;
   
}


class Transaction {
   byte[]   code;
   byte[]   response;
   long     departure;
   long     arrival;
   
   Transaction (byte[] code, byte[] response) {
      this.code      = code;
      this.response  = response;
      departure = arrival = 0;
   }
}