~drizzle-trunk/drizzle/development

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/*****************************************************************************

Copyright (c) 1996, 2009, Innobase Oy. 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, Inc., 51 Franklin
St, Fifth Floor, Boston, MA 02110-1301 USA

*****************************************************************************/

/********************************************************************//**
@file include/btr0sea.ic
The index tree adaptive search

Created 2/17/1996 Heikki Tuuri
*************************************************************************/

#include "dict0mem.h"
#include "btr0cur.h"
#include "buf0buf.h"

/*********************************************************************//**
Updates the search info. */
UNIV_INTERN
void
btr_search_info_update_slow(
/*========================*/
	btr_search_t*	info,	/*!< in/out: search info */
	btr_cur_t*	cursor);/*!< in: cursor which was just positioned */

/********************************************************************//**
Returns search info for an index.
@return	search info; search mutex reserved */
UNIV_INLINE
btr_search_t*
btr_search_get_info(
/*================*/
	dict_index_t*	index)	/*!< in: index */
{
	ut_ad(index);

	return(index->search_info);
}

/*********************************************************************//**
Updates the search info. */
UNIV_INLINE
void
btr_search_info_update(
/*===================*/
	dict_index_t*	index,	/*!< in: index of the cursor */
	btr_cur_t*	cursor)	/*!< in: cursor which was just positioned */
{
	btr_search_t*	info;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED));
	ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

	info = btr_search_get_info(index);

	info->hash_analysis++;

	if (info->hash_analysis < BTR_SEARCH_HASH_ANALYSIS) {

		/* Do nothing */

		return;

	}

	ut_ad(cursor->flag != BTR_CUR_HASH);

	btr_search_info_update_slow(info, cursor);
}