/* Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.

 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,
 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */

#ifndef _sql_cursor_h_
#define _sql_cursor_h_

#include "sql_class.h" /* Query_arena */

class JOIN;

/**
 @file

 Declarations for implementation of server side cursors. Only
 read-only non-scrollable cursors are currently implemented.
*/

/**
 Server_side_cursor -- an interface for materialized
 implementation of cursors. All cursors are self-contained
 (created in their own memory root). For that reason they must
 be deleted only using a pointer to Server_side_cursor, not to
 its base class.
*/

class Server_side_cursor: protected Query_arena, public Sql_alloc
{
protected:
 /** Row destination used for fetch */
 select_result *result;
public:
 Server_side_cursor(MEM_ROOT *mem_root_arg, select_result *result_arg)
 :Query_arena(mem_root_arg, STMT_INITIALIZED), result(result_arg)
 {}

 virtual bool is_open() const= 0;

 virtual int open(JOIN *top_level_join)= 0;
 virtual void fetch(ulong num_rows)= 0;
 virtual void close()= 0;
 virtual ~Server_side_cursor();

 static void operator delete(void *ptr, size_t size);
};


bool mysql_open_cursor(THD *thd, select_result *result,
 Server_side_cursor **res);

#endif /* _sql_cusor_h_ */