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

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

#include "btr0cur.h"
#include "buf0buf.h"
#include "dict0mem.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
const btr_search_t *btr_search_get_info(
    const dict_index_t *index) /*!< in: index */
{
  return (index->search_info);
}

/** 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]);
}