mariadb/storage/innobase/include/hash0hash.ic
2019-05-13 17:54:04 +03:00

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/*****************************************************************************
Copyright (c) 1997, 2015, 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, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/hash0hash.ic
The simple hash table utility
Created 5/20/1997 Heikki Tuuri
*******************************************************/
#include "ut0rnd.h"
/************************************************************//**
Gets the nth cell in a hash table.
@return pointer to cell */
UNIV_INLINE
hash_cell_t*
hash_get_nth_cell(
/*==============*/
hash_table_t* table, /*!< in: hash table */
ulint n) /*!< in: cell index */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ut_ad(n < table->n_cells);
return(table->array + n);
}
/*************************************************************//**
Clears a hash table so that all the cells become empty. */
UNIV_INLINE
void
hash_table_clear(
/*=============*/
hash_table_t* table) /*!< in/out: hash table */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
memset(table->array, 0x0,
table->n_cells * sizeof(*table->array));
}
/*************************************************************//**
Returns the number of cells in a hash table.
@return number of cells */
UNIV_INLINE
ulint
hash_get_n_cells(
/*=============*/
hash_table_t* table) /*!< in: table */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
return(table->n_cells);
}
/**************************************************************//**
Calculates the hash value from a folded value.
@return hashed value */
UNIV_INLINE
ulint
hash_calc_hash(
/*===========*/
ulint fold, /*!< in: folded value */
hash_table_t* table) /*!< in: hash table */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
return(ut_hash_ulint(fold, table->n_cells));
}
/************************************************************//**
Gets the sync object index for a fold value in a hash table.
@return index */
UNIV_INLINE
ulint
hash_get_sync_obj_index(
/*====================*/
hash_table_t* table, /*!< in: hash table */
ulint fold) /*!< in: fold */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ut_ad(table->type != HASH_TABLE_SYNC_NONE);
ut_ad(ut_is_2pow(table->n_sync_obj));
return(ut_2pow_remainder(hash_calc_hash(fold, table),
table->n_sync_obj));
}
/************************************************************//**
Gets the nth heap in a hash table.
@return mem heap */
UNIV_INLINE
mem_heap_t*
hash_get_nth_heap(
/*==============*/
hash_table_t* table, /*!< in: hash table */
ulint i) /*!< in: index of the heap */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ut_ad(table->type != HASH_TABLE_SYNC_NONE);
ut_ad(i < table->n_sync_obj);
return(table->heaps[i]);
}
/************************************************************//**
Gets the heap for a fold value in a hash table.
@return mem heap */
UNIV_INLINE
mem_heap_t*
hash_get_heap(
/*==========*/
hash_table_t* table, /*!< in: hash table */
ulint fold) /*!< in: fold */
{
ulint i;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
if (table->heap) {
return(table->heap);
}
i = hash_get_sync_obj_index(table, fold);
return(hash_get_nth_heap(table, i));
}
/************************************************************//**
Gets the nth mutex in a hash table.
@return mutex */
UNIV_INLINE
ib_mutex_t*
hash_get_nth_mutex(
/*===============*/
hash_table_t* table, /*!< in: hash table */
ulint i) /*!< in: index of the mutex */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
ut_ad(i < table->n_sync_obj);
return(table->sync_obj.mutexes + i);
}
/************************************************************//**
Gets the mutex for a fold value in a hash table.
@return mutex */
UNIV_INLINE
ib_mutex_t*
hash_get_mutex(
/*===========*/
hash_table_t* table, /*!< in: hash table */
ulint fold) /*!< in: fold */
{
ulint i;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
i = hash_get_sync_obj_index(table, fold);
return(hash_get_nth_mutex(table, i));
}
/************************************************************//**
Gets the nth rw_lock in a hash table.
@return rw_lock */
UNIV_INLINE
rw_lock_t*
hash_get_nth_lock(
/*==============*/
hash_table_t* table, /*!< in: hash table */
ulint i) /*!< in: index of the rw_lock */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
ut_ad(i < table->n_sync_obj);
return(table->sync_obj.rw_locks + i);
}
/************************************************************//**
Gets the rw_lock for a fold value in a hash table.
@return rw_lock */
UNIV_INLINE
rw_lock_t*
hash_get_lock(
/*==========*/
hash_table_t* table, /*!< in: hash table */
ulint fold) /*!< in: fold */
{
ulint i;
ut_ad(table);
ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
i = hash_get_sync_obj_index(table, fold);
return(hash_get_nth_lock(table, i));
}
/** If not appropriate rw_lock for a fold value in a hash table,
relock S-lock the another rw_lock until appropriate for a fold value.
@param[in] hash_lock latched rw_lock to be confirmed
@param[in] table hash table
@param[in] fold fold value
@return latched rw_lock */
UNIV_INLINE
rw_lock_t*
hash_lock_s_confirm(
rw_lock_t* hash_lock,
hash_table_t* table,
ulint fold)
{
ut_ad(rw_lock_own(hash_lock, RW_LOCK_S));
rw_lock_t* hash_lock_tmp = hash_get_lock(table, fold);
while (hash_lock_tmp != hash_lock) {
rw_lock_s_unlock(hash_lock);
hash_lock = hash_lock_tmp;
rw_lock_s_lock(hash_lock);
hash_lock_tmp = hash_get_lock(table, fold);
}
return(hash_lock);
}
/** If not appropriate rw_lock for a fold value in a hash table,
relock X-lock the another rw_lock until appropriate for a fold value.
@param[in] hash_lock latched rw_lock to be confirmed
@param[in] table hash table
@param[in] fold fold value
@return latched rw_lock */
UNIV_INLINE
rw_lock_t*
hash_lock_x_confirm(
rw_lock_t* hash_lock,
hash_table_t* table,
ulint fold)
{
ut_ad(rw_lock_own(hash_lock, RW_LOCK_X));
rw_lock_t* hash_lock_tmp = hash_get_lock(table, fold);
while (hash_lock_tmp != hash_lock) {
rw_lock_x_unlock(hash_lock);
hash_lock = hash_lock_tmp;
rw_lock_x_lock(hash_lock);
hash_lock_tmp = hash_get_lock(table, fold);
}
return(hash_lock);
}