135 lines
4.3 KiB
Plaintext
135 lines
4.3 KiB
Plaintext
/*****************************************************************************
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Copyright (c) 2007, 2018, Oracle and/or its affiliates. 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, version 2.0, as published by the
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Free Software Foundation.
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This program is also distributed with certain software (including but not
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limited to OpenSSL) that is licensed under separate terms, as designated in a
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particular file or component or in included license documentation. The authors
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of MySQL hereby grant you an additional permission to link the program and
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your derivative works with the separately licensed software that they have
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included with MySQL.
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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, version 2.0,
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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.,
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51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*****************************************************************************/
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/** @file include/ha0storage.ic
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Hash storage.
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Provides a data structure that stores chunks of data in
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its own storage, avoiding duplicates.
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Created September 24, 2007 Vasil Dimov
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*******************************************************/
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#include "ha0storage.h"
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#include "hash0hash.h"
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#include "mem0mem.h"
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#include "univ.i"
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/** Hash storage for strings */
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struct ha_storage_t {
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mem_heap_t *heap; /*!< memory heap from which memory is
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allocated */
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hash_table_t *hash; /*!< hash table used to avoid
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duplicates */
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};
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/** Objects of this type are stored in ha_storage_t */
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struct ha_storage_node_t {
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ulint data_len; /*!< length of the data */
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const void *data; /*!< pointer to data */
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ha_storage_node_t *next; /*!< next node in hash chain */
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};
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/** Creates a hash storage. If any of the parameters is 0, then a default
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value is used.
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@return own: hash storage */
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UNIV_INLINE
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ha_storage_t *ha_storage_create(
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ulint initial_heap_bytes, /*!< in: initial heap's size */
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ulint initial_hash_cells) /*!< in: initial number of cells
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in the hash table */
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{
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ha_storage_t *storage;
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mem_heap_t *heap;
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if (initial_heap_bytes == 0) {
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initial_heap_bytes = HA_STORAGE_DEFAULT_HEAP_BYTES;
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}
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if (initial_hash_cells == 0) {
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initial_hash_cells = HA_STORAGE_DEFAULT_HASH_CELLS;
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}
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/* we put "storage" within "storage->heap" */
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heap = mem_heap_create(sizeof(ha_storage_t) + initial_heap_bytes);
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storage = (ha_storage_t *)mem_heap_alloc(heap, sizeof(ha_storage_t));
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storage->heap = heap;
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storage->hash = hash_create(initial_hash_cells);
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return (storage);
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}
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/** Empties a hash storage, freeing memory occupied by data chunks.
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This invalidates any pointers previously returned by ha_storage_put().
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The hash storage is not invalidated itself and can be used again. */
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UNIV_INLINE
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void ha_storage_empty(ha_storage_t **storage) /*!< in/out: hash storage */
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{
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ha_storage_t temp_storage;
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temp_storage.heap = (*storage)->heap;
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temp_storage.hash = (*storage)->hash;
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hash_table_clear(temp_storage.hash);
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mem_heap_empty(temp_storage.heap);
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*storage =
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(ha_storage_t *)mem_heap_alloc(temp_storage.heap, sizeof(ha_storage_t));
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(*storage)->heap = temp_storage.heap;
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(*storage)->hash = temp_storage.hash;
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}
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/** Frees a hash storage and everything it contains, it cannot be used after
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this call.
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This invalidates any pointers previously returned by ha_storage_put(). */
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UNIV_INLINE
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void ha_storage_free(ha_storage_t *storage) /*!< in, own: hash storage */
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{
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/* order is important because the pointer storage->hash is
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within the heap */
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hash_table_free(storage->hash);
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mem_heap_free(storage->heap);
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}
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/** Gets the size of the memory used by a storage.
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@return bytes used */
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UNIV_INLINE
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ulint ha_storage_get_size(const ha_storage_t *storage) /*!< in: hash storage */
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{
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ulint ret;
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ret = mem_heap_get_size(storage->heap);
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/* this assumes hash->heap and hash->heaps are NULL */
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ret += sizeof(hash_table_t);
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ret += sizeof(hash_cell_t) * hash_get_n_cells(storage->hash);
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return (ret);
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}
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