~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems, Inc.

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; version 2 of the License.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#pragma once

#include <drizzled/function/str/strfunc.h>

namespace drizzled {

class Item_func_conv_charset :public Item_str_func

{

  bool use_cached_value;

public:

  bool safe;

  const charset_info_st *conv_charset; // keep it public

  Item_func_conv_charset(Item *a, const charset_info_st * const cs) :Item_str_func(a)

  { conv_charset= cs; use_cached_value= 0; safe= 0; }

  Item_func_conv_charset(Item *a, const charset_info_st * const cs, bool cache_if_const)

    :Item_str_func(a)

  {

    assert(args[0]->fixed);

    conv_charset= cs;

    if (cache_if_const && args[0]->const_item())

    {

      String tmp, *str= args[0]->val_str(&tmp);

      if (!str)

        null_value= 1;

      else

        str_value.copy(str->ptr(), str->length(), conv_charset);

      use_cached_value= 1;

      str_value.mark_as_const();

      safe= true;

    }

    else

    {

      use_cached_value= false;

      /*

        Conversion from and to "binary" is safe.

        Conversion to Unicode is safe.

        Other kind of conversions are potentially lossy.

      */

      safe= (args[0]->collation.collation == &my_charset_bin ||

             cs == &my_charset_bin ||

             (cs->state & MY_CS_UNICODE));

    }

  }

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "convert"; }

  virtual void print(String *str);

};

} /* namespace drizzled */