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

package net.hoo2.auth.vmodem;

import java.util.Arrays;
import ithakimodem.*;

class Com {
   static final int SPEED_DEFAULT   = 48000;
   static final int TIMEOUT_DEFAULT = 2000;
   static final String URL_DEFAULT  = "ithaki";

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

   Com () {
      modem_   = new Modem();
      speed_   = SPEED_DEFAULT;
      timeout_ = TIMEOUT_DEFAULT;
      modem_.setSpeed(speed_);
      modem_.setTimeout(timeout_);
   }
   Com (Log log, 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 timeout) {
      if (timeout_ != timeout) {
         timeout_ = timeout;
         modem_.setTimeout(timeout_);
      }
   }
   
   int  speed () { return speed_;  }
   void speed (int speed) {
      if (speed_ != 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, byte[] code, byte[] begin, byte[] end, boolean bin) {
      int ch =0;
      boolean have_begin = (begin != null) ? false : true;
      boolean incoming   = false;

      _clear (data.response, 0, data.response.length);
      if (code != null) {
         data.code = code;
         modem_.write(data.code);
         modem_.write((int)'\r');
         data.departure = System.currentTimeMillis();// - (long)((8*(data.code.length+1))*(1000.0/speed_));
      }
      data.size =0;
      do {
         if (data.size >= data.response.length) {
            data.size =0;
            return data;
         }
         try {
            ch = modem_.read();
         }
         catch (Exception e) {
            System.err.println (e.getMessage());
            data.size =0;
            return data;
         }
         if (!incoming) {
            incoming = true;
            data.arrival = System.currentTimeMillis();// - (long)(8*(1000.0/speed_));
         }
         data.response [data.size++] = (byte)ch;
         
         if (!have_begin && (detect(data.response, begin, data.size) != -1)) {
            _clear(data.response, 0, data.size);
            data.size = _copy (data.response, begin);
            have_begin = true;
         }
      } while (ch != -1 &&
                  (!have_begin ||
                     (  (bin || (detect (data.response, "\r\n\n\n".getBytes(), data.size) == -1))
                     && (bin || (detect (data.response, "NO CARRIER".getBytes(), data.size) == -1))
                     && (detect (data.response, end, data.size) == -1)
                     )
                  )
              );
      return data;
   }
   
   static int detect (byte[] data, byte[] pattern, int max) {
      if (pattern != null) {
         for (int i =0 ; i<max && i<data.length - pattern.length; ++i) {
            boolean detected = true;
            for (int j=0 ; j<pattern.length ; ++j) {
               if (data[i+j] != pattern[j]) {
                  detected = false;
                  break;
               }
            }
            if (detected)
               return i;
         }
      }
      return -1;
   }

   private void _clear (byte[] buffer, int begin, int end) {
      for (int i=begin ; i<end && i<buffer.length ; ++i)
         buffer[i] = 0;
   }
   
   private int _copy (byte[] dest, byte[] src) {
      if (dest.length >= src.length) {
         for (int i=0 ; i<src.length ; ++i)
            dest[i] = src[i];
         return src.length;
      }
      return 0;
   }
   
}


class Transaction {
   byte[]   code;
   byte[]   response;
   long     departure;
   long     arrival;
   int      size;
   
   Transaction (byte[] code, byte[] response) {
      this.code      = code;
      this.response  = response;
      departure      = arrival = 0;
      size           = 0;
   }
   
   byte[] getResponse() {
      return Arrays.copyOf(response, size);
   }
}