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142 lines
4.1 KiB
C++
142 lines
4.1 KiB
C++
/*****************************************************************************
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Copyright (c) 2007, 2013, 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 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.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
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*****************************************************************************/
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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 "hash0hash.h"
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#include "mem0mem.h"
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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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/*******************************************************************//**
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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*
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ha_storage_create(
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/*==============*/
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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)
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+ initial_heap_bytes);
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storage = (ha_storage_t*) mem_heap_alloc(heap,
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sizeof(ha_storage_t));
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storage->heap = heap;
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storage->hash.create(initial_hash_cells);
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return(storage);
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}
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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
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ha_storage_empty(
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/*=============*/
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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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temp_storage.hash.clear();
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mem_heap_empty(temp_storage.heap);
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*storage = (ha_storage_t*) mem_heap_alloc(temp_storage.heap,
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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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/*******************************************************************//**
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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
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ha_storage_free(
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/*============*/
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ha_storage_t* storage) /*!< in, own: hash storage */
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{
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storage->hash.free();
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mem_heap_free(storage->heap);
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}
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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
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ha_storage_get_size(
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/*================*/
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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) * storage->hash.n_cells;
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return(ret);
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}
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