btr0sea.ic

来自「这是linux下运行的mysql软件包,可用于linux 下安装 php + m」· IC 代码 · 共 68 行

/************************************************************************
The index tree adaptive search

(c) 1996 Innobase Oy

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

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

/*************************************************************************
Updates the search info. */

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. */
UNIV_INLINE
btr_search_t*
btr_search_get_info(
/*================*/
				/* out: search info; search mutex reserved */
	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);
}