~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

 *

 *  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 <drizzled/server_includes.h>

#include CSTDINT_H

#include <drizzled/function/get_variable.h>

#include <drizzled/session.h>

#define extra_size sizeof(double)

user_var_entry *get_variable(HASH *hash, LEX_STRING &name,

                             bool create_if_not_exists)

{

  user_var_entry *entry;

  if (!(entry = (user_var_entry*) hash_search(hash, (unsigned char*) name.str,

					      name.length)) &&

      create_if_not_exists)

  {

    uint32_t size=ALIGN_SIZE(sizeof(user_var_entry))+name.length+1+extra_size;

    if (!hash_inited(hash))

      return 0;

    if (!(entry = (user_var_entry*) malloc(size)))

      return 0;

    entry->name.str=(char*) entry+ ALIGN_SIZE(sizeof(user_var_entry))+

      extra_size;

    entry->name.length=name.length;

    entry->value=0;

    entry->length=0;

    entry->update_query_id=0;

    entry->collation.set(NULL, DERIVATION_IMPLICIT, 0);

    entry->unsigned_flag= 0;

    /*

      If we are here, we were called from a SET or a query which sets a

      variable. Imagine it is this:

      INSERT INTO t SELECT @a:=10, @a:=@a+1.

      Then when we have a Item_func_get_user_var (because of the @a+1) so we

      think we have to write the value of @a to the binlog. But before that,

      we have a Item_func_set_user_var to create @a (@a:=10), in this we mark

      the variable as "already logged" (line below) so that it won't be logged

      by Item_func_get_user_var (because that's not necessary).

    */

    entry->used_query_id=current_session->query_id;

    entry->type=STRING_RESULT;

    memcpy(entry->name.str, name.str, name.length+1);

    if (my_hash_insert(hash,(unsigned char*) entry))

    {

      free((char*) entry);

      return 0;

    }

  }

  return entry;

}