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Diffstat (limited to 'storage/innobase/include/hash0hash.h')
-rw-r--r-- | storage/innobase/include/hash0hash.h | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/storage/innobase/include/hash0hash.h b/storage/innobase/include/hash0hash.h new file mode 100644 index 00000000..867ad9e0 --- /dev/null +++ b/storage/innobase/include/hash0hash.h @@ -0,0 +1,190 @@ +/***************************************************************************** + +Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved. +Copyright (c) 2018, 2022, MariaDB Corporation. + +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.h +The simple hash table utility + +Created 5/20/1997 Heikki Tuuri +*******************************************************/ + +#pragma once +#include "ut0rnd.h" +#include "ut0new.h" + +struct hash_table_t; +struct hash_cell_t +{ + /** singly-linked, nullptr terminated list of hash buckets */ + void *node; + + /** Append an element. + @tparam T type of the element + @param insert the being-inserted element + @param next the next-element pointer in T */ + template<typename T> + void append(T &insert, T *T::*next) + { + void **after; + for (after= &node; *after; + after= reinterpret_cast<void**>(&(static_cast<T*>(*after)->*next))); + insert.*next= nullptr; + *after= &insert; + } +}; + +/*******************************************************************//** +Inserts a struct to a hash table. */ + +#define HASH_INSERT(TYPE, NAME, TABLE, FOLD, DATA)\ +do {\ + hash_cell_t* cell3333;\ + TYPE* struct3333;\ +\ + (DATA)->NAME = NULL;\ +\ + cell3333 = &(TABLE)->array[(TABLE)->calc_hash(FOLD)]; \ +\ + if (cell3333->node == NULL) {\ + cell3333->node = DATA;\ + } else {\ + struct3333 = (TYPE*) cell3333->node;\ +\ + while (struct3333->NAME != NULL) {\ +\ + struct3333 = (TYPE*) struct3333->NAME;\ + }\ +\ + struct3333->NAME = DATA;\ + }\ +} while (0) + +#ifdef UNIV_HASH_DEBUG +# define HASH_ASSERT_VALID(DATA) ut_a((void*) (DATA) != (void*) -1) +# define HASH_INVALIDATE(DATA, NAME) *(void**) (&DATA->NAME) = (void*) -1 +#else +# define HASH_ASSERT_VALID(DATA) do {} while (0) +# define HASH_INVALIDATE(DATA, NAME) do {} while (0) +#endif + +/*******************************************************************//** +Deletes a struct from a hash table. */ + +#define HASH_DELETE(TYPE, NAME, TABLE, FOLD, DATA)\ +do {\ + hash_cell_t* cell3333;\ + TYPE* struct3333;\ +\ + cell3333 = &(TABLE)->array[(TABLE)->calc_hash(FOLD)]; \ +\ + if (cell3333->node == DATA) {\ + HASH_ASSERT_VALID(DATA->NAME);\ + cell3333->node = DATA->NAME;\ + } else {\ + struct3333 = (TYPE*) cell3333->node;\ +\ + while (struct3333->NAME != DATA) {\ +\ + struct3333 = (TYPE*) struct3333->NAME;\ + ut_a(struct3333);\ + }\ +\ + struct3333->NAME = DATA->NAME;\ + }\ + HASH_INVALIDATE(DATA, NAME);\ +} while (0) + +/*******************************************************************//** +Gets the first struct in a hash chain, NULL if none. */ + +#define HASH_GET_FIRST(TABLE, HASH_VAL) (TABLE)->array[HASH_VAL].node + +/*******************************************************************//** +Gets the next struct in a hash chain, NULL if none. */ + +#define HASH_GET_NEXT(NAME, DATA) ((DATA)->NAME) + +/********************************************************************//** +Looks for a struct in a hash table. */ +#define HASH_SEARCH(NAME, TABLE, FOLD, TYPE, DATA, ASSERTION, TEST)\ +{\ + (DATA) = (TYPE) HASH_GET_FIRST(TABLE, (TABLE)->calc_hash(FOLD)); \ + HASH_ASSERT_VALID(DATA);\ +\ + while ((DATA) != NULL) {\ + ASSERTION;\ + if (TEST) {\ + break;\ + } else {\ + HASH_ASSERT_VALID(HASH_GET_NEXT(NAME, DATA));\ + (DATA) = (TYPE) HASH_GET_NEXT(NAME, DATA);\ + }\ + }\ +} + +/********************************************************************//** +Looks for an item in all hash buckets. */ +#define HASH_SEARCH_ALL(NAME, TABLE, TYPE, DATA, ASSERTION, TEST) \ +do { \ + ulint i3333; \ + \ + for (i3333 = (TABLE)->n_cells; i3333--; ) { \ + (DATA) = (TYPE) HASH_GET_FIRST(TABLE, i3333); \ + \ + while ((DATA) != NULL) { \ + HASH_ASSERT_VALID(DATA); \ + ASSERTION; \ + \ + if (TEST) { \ + break; \ + } \ + \ + (DATA) = (TYPE) HASH_GET_NEXT(NAME, DATA); \ + } \ + \ + if ((DATA) != NULL) { \ + break; \ + } \ + } \ +} while (0) + +/** Hash table with singly-linked overflow lists */ +struct hash_table_t +{ + /** number of elements in array (a prime number) */ + ulint n_cells; + /** the hash array */ + hash_cell_t *array; + + /** Create the hash table. + @param n the lower bound of n_cells */ + void create(ulint n) + { + n_cells= ut_find_prime(n); + array= static_cast<hash_cell_t*>(ut_zalloc_nokey(n_cells * sizeof *array)); + } + + /** Clear the hash table. */ + void clear() { memset(array, 0, n_cells * sizeof *array); } + + /** Free the hash table. */ + void free() { ut_free(array); array= nullptr; } + + ulint calc_hash(ulint fold) const { return ut_hash_ulint(fold, n_cells); } +}; |