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

Copyright (c) 1996, 2023, Oracle and/or its affiliates.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.

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but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation.  The authors of MySQL hereby grant you an additional
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This program is distributed in the hope that it will be useful,
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License, version 2.0, 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.,
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*****************************************************************************/

/********************************************************************//**
@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. */
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 */
{
	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 */
{
	ut_ad(!rw_lock_own(btr_get_search_latch(index), RW_LOCK_S));
	ut_ad(!rw_lock_own(btr_get_search_latch(index), RW_LOCK_X));

	if (dict_index_is_spatial(index) || !btr_search_enabled) {
		return;
	}

	btr_search_t*	info;
	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);
}

/** X-Lock the search latch (corresponding to given index)
@param[in]	index	index handler */
UNIV_INLINE
void
btr_search_x_lock(const dict_index_t* index)
{
	rw_lock_x_lock(btr_get_search_latch(index));
}

/** X-Unlock the search latch (corresponding to given index)
@param[in]	index	index handler */
UNIV_INLINE
void
btr_search_x_unlock(const dict_index_t* index)
{
	rw_lock_x_unlock(btr_get_search_latch(index));
}

/** Lock all search latches in exclusive mode. */
UNIV_INLINE
void
btr_search_x_lock_all()
{
	for (ulint i = 0; i < btr_ahi_parts; ++i) {
		rw_lock_x_lock(btr_search_latches[i]);
	}
}

/** Unlock all search latches from exclusive mode. */
UNIV_INLINE
void
btr_search_x_unlock_all()
{
	for (ulint i = 0; i < btr_ahi_parts; ++i) {
		rw_lock_x_unlock(btr_search_latches[i]);
	}
}

/** S-Lock the search latch (corresponding to given index)
@param[in]	index	index handler */
UNIV_INLINE
void
btr_search_s_lock(const dict_index_t* index)
{
	rw_lock_s_lock(btr_get_search_latch(index));
}

/** S-Unlock the search latch (corresponding to given index)
@param[in]	index	index handler */
UNIV_INLINE
void
btr_search_s_unlock(const dict_index_t* index)
{
	rw_lock_s_unlock(btr_get_search_latch(index));
}

/** Lock all search latches in shared mode. */
UNIV_INLINE
void
btr_search_s_lock_all()
{
	for (ulint i = 0; i < btr_ahi_parts; ++i) {
		rw_lock_s_lock(btr_search_latches[i]);
	}
}

/** Unlock all search latches from shared mode. */
UNIV_INLINE
void
btr_search_s_unlock_all()
{
	for (ulint i = 0; i < btr_ahi_parts; ++i) {
		rw_lock_s_unlock(btr_search_latches[i]);
	}
}

#ifdef UNIV_DEBUG
/** Check if thread owns all the search latches.
@param[in]	mode	lock mode check
@retval true if owns all of them
@retval false if does not own some of them */
UNIV_INLINE
bool
btr_search_own_all(ulint mode)
{
	for (ulint i = 0; i < btr_ahi_parts; ++i) {
		if (!rw_lock_own(btr_search_latches[i], mode)) {
			return(false);
		}
	}
	return(true);
}

/** Check if thread owns any of the search latches.
@param[in]	mode	lock mode check
@retval true if owns any of them
@retval false if owns no search latch */
UNIV_INLINE
bool
btr_search_own_any(ulint mode)
{
	for (ulint i = 0; i < btr_ahi_parts; ++i) {
		if (rw_lock_own(btr_search_latches[i], mode)) {
			return(true);
		}
	}
	return(false);
}
#endif /* UNIV_DEBUG */

/** Get the adaptive hash search index latch for a b-tree.
@param[in]	index	b-tree index
@return latch */
UNIV_INLINE
rw_lock_t*
btr_get_search_latch(const dict_index_t* index)
{
	ut_ad(index != NULL);

	ulint	ifold = ut_fold_ulint_pair(static_cast<ulint>(index->id),
					   static_cast<ulint>(index->space));

	return(btr_search_latches[ifold % btr_ahi_parts]);
}

/** Get the hash-table based on index attributes.
A table is selected from an array of tables using pair of index-id, space-id.
@param[in]	index	index handler
@return hash table */
UNIV_INLINE
hash_table_t*
btr_get_search_table(const dict_index_t* index)
{
	ut_ad(index != NULL);

	ulint	ifold = ut_fold_ulint_pair(static_cast<ulint>(index->id),
					   static_cast<ulint>(index->space));

	return(btr_search_sys->hash_tables[ifold % btr_ahi_parts]);
}