diff options
Diffstat (limited to 'storage/xtradb/include/hash0hash.ic')
-rw-r--r-- | storage/xtradb/include/hash0hash.ic | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/storage/xtradb/include/hash0hash.ic b/storage/xtradb/include/hash0hash.ic new file mode 100644 index 00000000000..792fdcbf4f8 --- /dev/null +++ b/storage/xtradb/include/hash0hash.ic @@ -0,0 +1,160 @@ +/***************************************************************************** + +Copyright (c) 1997, 2009, Innobase Oy. 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., 59 Temple +Place, Suite 330, Boston, MA 02111-1307 USA + +*****************************************************************************/ + +/****************************************************** +The simple hash table utility + +Created 5/20/1997 Heikki Tuuri +*******************************************************/ + +#include "ut0rnd.h" + +/**************************************************************** +Gets the nth cell in a hash table. */ +UNIV_INLINE +hash_cell_t* +hash_get_nth_cell( +/*==============*/ + /* out: pointer to cell */ + hash_table_t* table, /* in: hash table */ + ulint n) /* in: cell index */ +{ + 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 */ +{ + memset(table->array, 0x0, + table->n_cells * sizeof(*table->array)); +} + +/***************************************************************** +Returns the number of cells in a hash table. */ +UNIV_INLINE +ulint +hash_get_n_cells( +/*=============*/ + /* out: number of cells */ + hash_table_t* table) /* in: table */ +{ + return(table->n_cells); +} + +/****************************************************************** +Calculates the hash value from a folded value. */ +UNIV_INLINE +ulint +hash_calc_hash( +/*===========*/ + /* out: hashed value */ + ulint fold, /* in: folded value */ + hash_table_t* table) /* in: hash table */ +{ + return(ut_hash_ulint(fold, table->n_cells)); +} + +/**************************************************************** +Gets the mutex index for a fold value in a hash table. */ +UNIV_INLINE +ulint +hash_get_mutex_no( +/*==============*/ + /* out: mutex number */ + hash_table_t* table, /* in: hash table */ + ulint fold) /* in: fold */ +{ + ut_ad(ut_is_2pow(table->n_mutexes)); + return(ut_2pow_remainder(hash_calc_hash(fold, table), + table->n_mutexes)); +} + +/**************************************************************** +Gets the nth heap in a hash table. */ +UNIV_INLINE +mem_heap_t* +hash_get_nth_heap( +/*==============*/ + /* out: mem heap */ + hash_table_t* table, /* in: hash table */ + ulint i) /* in: index of the heap */ +{ + ut_ad(i < table->n_mutexes); + + return(table->heaps[i]); +} + +/**************************************************************** +Gets the heap for a fold value in a hash table. */ +UNIV_INLINE +mem_heap_t* +hash_get_heap( +/*==========*/ + /* out: mem heap */ + hash_table_t* table, /* in: hash table */ + ulint fold) /* in: fold */ +{ + ulint i; + + if (table->heap) { + return(table->heap); + } + + i = hash_get_mutex_no(table, fold); + + return(hash_get_nth_heap(table, i)); +} + +/**************************************************************** +Gets the nth mutex in a hash table. */ +UNIV_INLINE +mutex_t* +hash_get_nth_mutex( +/*===============*/ + /* out: mutex */ + hash_table_t* table, /* in: hash table */ + ulint i) /* in: index of the mutex */ +{ + ut_ad(i < table->n_mutexes); + + return(table->mutexes + i); +} + +/**************************************************************** +Gets the mutex for a fold value in a hash table. */ +UNIV_INLINE +mutex_t* +hash_get_mutex( +/*===========*/ + /* out: mutex */ + hash_table_t* table, /* in: hash table */ + ulint fold) /* in: fold */ +{ + ulint i; + + i = hash_get_mutex_no(table, fold); + + return(hash_get_nth_mutex(table, i)); +} |