1/***************************************************************************** 2 3Copyright (c) 2007, 2018, Oracle and/or its affiliates. All Rights Reserved. 4 5This program is free software; you can redistribute it and/or modify it under 6the terms of the GNU General Public License, version 2.0, as published by the 7Free Software Foundation. 8 9This program is also distributed with certain software (including but not 10limited to OpenSSL) that is licensed under separate terms, as designated in a 11particular file or component or in included license documentation. The authors 12of MySQL hereby grant you an additional permission to link the program and 13your derivative works with the separately licensed software that they have 14included with MySQL. 15 16This program is distributed in the hope that it will be useful, but WITHOUT 17ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 18FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, 19for more details. 20 21You should have received a copy of the GNU General Public License along with 22this program; if not, write to the Free Software Foundation, Inc., 2351 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 24 25*****************************************************************************/ 26 27/** @file include/ha0storage.ic 28 Hash storage. 29 Provides a data structure that stores chunks of data in 30 its own storage, avoiding duplicates. 31 32 Created September 24, 2007 Vasil Dimov 33 *******************************************************/ 34 35#include "ha0storage.h" 36#include "hash0hash.h" 37#include "mem0mem.h" 38#include "univ.i" 39 40/** Hash storage for strings */ 41struct ha_storage_t { 42 mem_heap_t *heap; /*!< memory heap from which memory is 43 allocated */ 44 hash_table_t *hash; /*!< hash table used to avoid 45 duplicates */ 46}; 47 48/** Objects of this type are stored in ha_storage_t */ 49struct ha_storage_node_t { 50 ulint data_len; /*!< length of the data */ 51 const void *data; /*!< pointer to data */ 52 ha_storage_node_t *next; /*!< next node in hash chain */ 53}; 54 55/** Creates a hash storage. If any of the parameters is 0, then a default 56 value is used. 57 @return own: hash storage */ 58UNIV_INLINE 59ha_storage_t *ha_storage_create( 60 ulint initial_heap_bytes, /*!< in: initial heap's size */ 61 ulint initial_hash_cells) /*!< in: initial number of cells 62 in the hash table */ 63{ 64 ha_storage_t *storage; 65 mem_heap_t *heap; 66 67 if (initial_heap_bytes == 0) { 68 initial_heap_bytes = HA_STORAGE_DEFAULT_HEAP_BYTES; 69 } 70 71 if (initial_hash_cells == 0) { 72 initial_hash_cells = HA_STORAGE_DEFAULT_HASH_CELLS; 73 } 74 75 /* we put "storage" within "storage->heap" */ 76 77 heap = mem_heap_create(sizeof(ha_storage_t) + initial_heap_bytes); 78 79 storage = (ha_storage_t *)mem_heap_alloc(heap, sizeof(ha_storage_t)); 80 81 storage->heap = heap; 82 storage->hash = hash_create(initial_hash_cells); 83 84 return (storage); 85} 86 87/** Empties a hash storage, freeing memory occupied by data chunks. 88 This invalidates any pointers previously returned by ha_storage_put(). 89 The hash storage is not invalidated itself and can be used again. */ 90UNIV_INLINE 91void ha_storage_empty(ha_storage_t **storage) /*!< in/out: hash storage */ 92{ 93 ha_storage_t temp_storage; 94 95 temp_storage.heap = (*storage)->heap; 96 temp_storage.hash = (*storage)->hash; 97 98 hash_table_clear(temp_storage.hash); 99 mem_heap_empty(temp_storage.heap); 100 101 *storage = 102 (ha_storage_t *)mem_heap_alloc(temp_storage.heap, sizeof(ha_storage_t)); 103 104 (*storage)->heap = temp_storage.heap; 105 (*storage)->hash = temp_storage.hash; 106} 107 108/** Frees a hash storage and everything it contains, it cannot be used after 109 this call. 110 This invalidates any pointers previously returned by ha_storage_put(). */ 111UNIV_INLINE 112void ha_storage_free(ha_storage_t *storage) /*!< in, own: hash storage */ 113{ 114 /* order is important because the pointer storage->hash is 115 within the heap */ 116 hash_table_free(storage->hash); 117 mem_heap_free(storage->heap); 118} 119 120/** Gets the size of the memory used by a storage. 121 @return bytes used */ 122UNIV_INLINE 123ulint ha_storage_get_size(const ha_storage_t *storage) /*!< in: hash storage */ 124{ 125 ulint ret; 126 127 ret = mem_heap_get_size(storage->heap); 128 129 /* this assumes hash->heap and hash->heaps are NULL */ 130 ret += sizeof(hash_table_t); 131 ret += sizeof(hash_cell_t) * hash_get_n_cells(storage->hash); 132 133 return (ret); 134} 135