static protected void AdjustBuffSize()
  {
    if (available == bufsize)
    {
      if (tokenBegin > 2048)
      {
        bufpos = 0;
        available = tokenBegin;
      }
      else
        ExpandBuff(false);
    }
    else if (available > tokenBegin)
      available = bufsize;
    else if ((tokenBegin - available) < 2048)
      ExpandBuff(true);
    else
      available = tokenBegin;
  }