~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

 */

#include "config.h"

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

#include <drizzled/session.h>

namespace drizzled

{

void Item_func_make_set::update_used_tables()

{

  Item_func::update_used_tables();

  item->update_used_tables();

  used_tables_cache|=item->used_tables();

  const_item_cache&=item->const_item();

}

void Item_func_make_set::split_sum_func(Session *session_arg, Item **ref_pointer_array,

					List<Item> &fields)

{

  item->split_sum_func(session_arg, ref_pointer_array, fields, &item, true);

  Item_str_func::split_sum_func(session_arg, ref_pointer_array, fields);

}

void Item_func_make_set::fix_length_and_dec()

{

  max_length=arg_count-1;

  if (agg_arg_charsets(collation, args, arg_count, MY_COLL_ALLOW_CONV, 1))

    return;

  for (uint32_t i=0 ; i < arg_count ; i++)

    max_length+=args[i]->max_length;

  used_tables_cache|=	  item->used_tables();

  not_null_tables_cache&= item->not_null_tables();

  const_item_cache&=	  item->const_item();

  with_sum_func= with_sum_func || item->with_sum_func;

}

String *Item_func_make_set::val_str(String *str)

{

  assert(fixed == 1);

  uint64_t bits;

  bool first_found=0;

  Item **ptr=args;

  String *result=&my_empty_string;

  bits=item->val_int();

  if ((null_value=item->null_value))

    return NULL;

  if (arg_count < 64)

    bits &= ((uint64_t) 1 << arg_count)-1;

  for (; bits; bits >>= 1, ptr++)

  {

    if (bits & 1)

    {

      String *res= (*ptr)->val_str(str);

      if (res)					// Skip nulls

      {

	if (!first_found)

	{					// First argument

	  first_found=1;

	  if (res != str)

	    result=res;				// Use original string

	  else

	  {

	    if (tmp_str.copy(*res))		// Don't use 'str'

	      return &my_empty_string;

	    result= &tmp_str;

	  }

	}

	else

	{

	  if (result != &tmp_str)

	  {					// Copy data to tmp_str

	    if (tmp_str.alloc(result->length()+res->length()+1) ||

		tmp_str.copy(*result))

	      return &my_empty_string;

	    result= &tmp_str;

	  }

	  if (tmp_str.append(STRING_WITH_LEN(","), &my_charset_bin) || tmp_str.append(*res))

	    return &my_empty_string;

	}

      }

    }

  }

  return result;

}

Item *Item_func_make_set::transform(Item_transformer transformer, unsigned char *arg)

{

  Item *new_item= item->transform(transformer, arg);

  if (!new_item)

    return 0;

  /*

    Session::change_item_tree() should be called only if the tree was

    really transformed, i.e. when a new item has been created.

    Otherwise we'll be allocating a lot of unnecessary memory for

    change records at each execution.

  */

  if (item != new_item)

    session.change_item_tree(&item, new_item);

  return Item_str_func::transform(transformer, arg);

}

void Item_func_make_set::print(String *str, enum_query_type query_type)

{

  str->append(STRING_WITH_LEN("make_set("));

  item->print(str, query_type);

  if (arg_count)

  {

    str->append(',');

    print_args(str, 0, query_type);

  }

  str->append(')');

}

} /* namespace drizzled */