OnlineDDL-Example2.c

  /*
    Copy a field part into an output buffer.
    SYNOPSIS
      Field::get_key_image()
      buff   [out] output buffer
      length       output buffer size
      type         itMBR for geometry blobs, otherwise itRAW
    DESCRIPTION
      This function makes a copy of field part of size equal to or
      less than "length" parameter value.
      For fields of string types (CHAR, VARCHAR, TEXT) the rest of buffer
      is padded by zero byte.
    NOTES
      For variable length character fields (i.e. UTF-8) the "length"
      parameter means a number of output buffer bytes as if all field
      characters have maximal possible size (mbmaxlen). In the other words,
      "length" parameter is a number of characters multiplied by
      field_charset->mbmaxlen.
    RETURN
      Number of copied bytes (excluding padded zero bytes -- see above).
  */

  virtual size_t get_key_image(uchar *buff, size_t length, imagetype type)
  {
    get_image(buff, length, &my_charset_bin);
    return length;
  }
  virtual void set_key_image(const uchar *buff, size_t length)
    { set_image(buff,length, &my_charset_bin); }
  inline longlong val_int_offset(uint row_offset)
    {
      ptr+=row_offset;
      longlong tmp=val_int();
      ptr-=row_offset;
      return tmp;
    }
  inline longlong val_int(const uchar *new_ptr)
  {
    uchar *old_ptr= ptr;
    longlong return_value;
    ptr= (uchar*) new_ptr;
    return_value= val_int();
    ptr= old_ptr;
    return return_value;
  }
  inline String *val_str(String *str, const uchar *new_ptr)
  {
    uchar *old_ptr= ptr;
    ptr= (uchar*) new_ptr;
    val_str(str);
    ptr= old_ptr;
    return str;
  }
  virtual bool send_binary(Protocol *protocol);
  virtual bool send_text(Protocol *protocol);

  virtual uchar *pack(uchar *to, const uchar *from,
uint max_length, bool low_byte_first);