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52f0c662d2
* Remove old Innobase copyright lines from C source files * Add a reference to the GPLv2 license as recommended by the lawyers at Oracle Legal [Step 9/28]
160 lines
4 KiB
Text
160 lines
4 KiB
Text
/*****************************************************************************
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Copyright (c) 1997, 2009, Innobase Oy. All Rights Reserved.
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free Software
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Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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Place, Suite 330, Boston, MA 02111-1307 USA
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*****************************************************************************/
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/******************************************************
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The simple hash table utility
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Created 5/20/1997 Heikki Tuuri
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*******************************************************/
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#include "ut0rnd.h"
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/****************************************************************
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Gets the nth cell in a hash table. */
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UNIV_INLINE
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hash_cell_t*
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hash_get_nth_cell(
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/*==============*/
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/* out: pointer to cell */
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hash_table_t* table, /* in: hash table */
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ulint n) /* in: cell index */
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{
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ut_ad(n < table->n_cells);
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return(table->array + n);
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}
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/*****************************************************************
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Clears a hash table so that all the cells become empty. */
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UNIV_INLINE
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void
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hash_table_clear(
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/*=============*/
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hash_table_t* table) /* in/out: hash table */
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{
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memset(table->array, 0x0,
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table->n_cells * sizeof(*table->array));
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}
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/*****************************************************************
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Returns the number of cells in a hash table. */
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UNIV_INLINE
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ulint
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hash_get_n_cells(
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/*=============*/
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/* out: number of cells */
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hash_table_t* table) /* in: table */
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{
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return(table->n_cells);
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}
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/******************************************************************
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Calculates the hash value from a folded value. */
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UNIV_INLINE
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ulint
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hash_calc_hash(
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/*===========*/
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/* out: hashed value */
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ulint fold, /* in: folded value */
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hash_table_t* table) /* in: hash table */
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{
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return(ut_hash_ulint(fold, table->n_cells));
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}
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/****************************************************************
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Gets the mutex index for a fold value in a hash table. */
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UNIV_INLINE
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ulint
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hash_get_mutex_no(
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/*==============*/
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/* out: mutex number */
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hash_table_t* table, /* in: hash table */
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ulint fold) /* in: fold */
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{
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ut_ad(ut_is_2pow(table->n_mutexes));
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return(ut_2pow_remainder(hash_calc_hash(fold, table),
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table->n_mutexes));
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}
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/****************************************************************
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Gets the nth heap in a hash table. */
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UNIV_INLINE
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mem_heap_t*
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hash_get_nth_heap(
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/*==============*/
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/* out: mem heap */
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hash_table_t* table, /* in: hash table */
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ulint i) /* in: index of the heap */
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{
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ut_ad(i < table->n_mutexes);
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return(table->heaps[i]);
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}
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/****************************************************************
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Gets the heap for a fold value in a hash table. */
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UNIV_INLINE
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mem_heap_t*
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hash_get_heap(
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/*==========*/
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/* out: mem heap */
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hash_table_t* table, /* in: hash table */
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ulint fold) /* in: fold */
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{
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ulint i;
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if (table->heap) {
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return(table->heap);
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}
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i = hash_get_mutex_no(table, fold);
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return(hash_get_nth_heap(table, i));
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}
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/****************************************************************
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Gets the nth mutex in a hash table. */
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UNIV_INLINE
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mutex_t*
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hash_get_nth_mutex(
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/*===============*/
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/* out: mutex */
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hash_table_t* table, /* in: hash table */
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ulint i) /* in: index of the mutex */
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{
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ut_ad(i < table->n_mutexes);
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return(table->mutexes + i);
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}
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/****************************************************************
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Gets the mutex for a fold value in a hash table. */
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UNIV_INLINE
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mutex_t*
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hash_get_mutex(
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/*===========*/
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/* out: mutex */
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hash_table_t* table, /* in: hash table */
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ulint fold) /* in: fold */
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{
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ulint i;
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i = hash_get_mutex_no(table, fold);
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return(hash_get_nth_mutex(table, i));
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}
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