Name: tb29552 Date: 03/23/2001


class BitTest {
   private static boolean isDebug = true;
   private int total = 0;
   private int errorCount = 0;
   private byte buf[] = new byte[500];
   private int ofsStartPut = 0;
   private int blen = 0;

   int bitSwizzle(int b1, int b2) {
        int b3 = (b1 >> 4) | ((b2 & 0x3) << 4);
        return b3;
   }


   private final void encode(byte[] inBuf, int inStart, int inEnd)
   {
      ofsStartPut = 0;
      int iTimes = -1;
      int b1;
      int b2 = 0;
      int b2Correct;
      blen += (inEnd - inStart);
      while (inStart < inEnd) {
         b1 = inBuf[inStart++] & 0xFF;
         switch (++iTimes) {
         case 0:
            b2 = b1>>2;
            break;
         case 1:
            b2Correct = bitSwizzle(b1, b2);
            b2 = (b1>>4) | ((b2 & 0x3)<<4);
            if (isDebug) {
               ++total;
               if (b2 != b2Correct) {
                   ++errorCount;
                   System.err.println(
                      "Error: Expecting: 0x" + Integer.toHexString(b2Correct) +
                      " received: 0x" + Integer.toHexString(b2)
                   );
               }
            }
            break;
         default: // case 2:
            buf[ofsStartPut++] = (byte)((b1>>6) | ((b2 & 0xF)<<2));
            b2 = b1 & 0x3f;
            iTimes = -1;
            break;
         }
         buf[ofsStartPut++] = (byte)b2;
         b2 = b1;
      }

      switch (iTimes) { // take care of orphans!
      case 0:
         buf[ofsStartPut++] = (byte)((b2 & 0x3)<<4);
         break;
      case 1:
         buf[ofsStartPut++] = (byte)((b2 & 0xF)<<2);
         break;
      default: // case 2 (really: -1)
         break;
      }
   }

    public static void main(String[] args) {
        int errorCount = 0;
        BitTest my = new BitTest();

        for (int k=0; k < 50; ++k) {
          /* ----+----1----+----2----+----3----+----4----- */
           my.encode(
              "Hello World.\r\nHello World.\r\nAbcdefg Abcdefg A".getBytes(),
              0,
              45
           );
        }
        System.out.println(
           "Total errors this run: " + my.errorCount +
           " for a total of " + my.total + " bit swizzlings"
        );
    }
}

(Review ID: 119299)
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