~drizzle-trunk/drizzle/development

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

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

 *

 *  Copyright (C) 2009 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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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/show.h>

#include <drizzled/lock.h>

#include <drizzled/session.h>

#include <drizzled/statement/replace_select.h>

#include <drizzled/select_insert.h>

#include <drizzled/sql_lex.h>

namespace drizzled {

bool statement::ReplaceSelect::execute()

{

  TableList *first_table= (TableList *) lex().select_lex.table_list.first;

  TableList *all_tables= lex().query_tables;

  assert(first_table == all_tables && first_table != 0);

  Select_Lex *select_lex= &lex().select_lex;

  Select_Lex_Unit *unit= &lex().unit;

  select_result *sel_result= NULL;

  bool res;

  if (insert_precheck(&session(), all_tables))

  {

    return true;

  }

  /* Don't unlock tables until command is written to binary log */

  select_lex->options|= SELECT_NO_UNLOCK;

  unit->set_limit(select_lex);

  if (session().wait_if_global_read_lock(false, true))

  {

    return true;

  }

  if (! (res= session().openTablesLock(all_tables)))

  {

    /* Skip first table, which is the table we are inserting in */

    TableList *second_table= first_table->next_local;

    select_lex->table_list.first= (unsigned char*) second_table;

    select_lex->context.table_list=

      select_lex->context.first_name_resolution_table= second_table;

    res= insert_select_prepare(&session());

    if (! res && (sel_result= new select_insert(first_table,

                                                first_table->table,

                                                &lex().field_list,

                                                &lex().update_list,

                                                &lex().value_list,

                                                lex().duplicates,

                                                lex().ignore)))

    {

      res= handle_select(&session(),

                         &lex(),

                         sel_result,

                         OPTION_SETUP_TABLES_DONE);

      /*

         Invalidate the table in the query cache if something changed

         after unlocking when changes become visible.

         TODO: this is a workaround. right way will be move invalidating in

         the unlock procedure.

       */

      if (first_table->lock_type == TL_WRITE_CONCURRENT_INSERT &&

          session().lock)

      {

        /* INSERT ... SELECT should invalidate only the very first table */

        TableList *save_table= first_table->next_local;

        first_table->next_local= 0;

        first_table->next_local= save_table;

      }

      delete sel_result;

    }

    /* revert changes for SP */

    select_lex->table_list.first= (unsigned char*) first_table;

  }

  /*

     Release the protection against the global read lock and wake

     everyone, who might want to set a global read lock.

   */

  session().startWaitingGlobalReadLock();

  return res;

}

} /* namespace drizzled */