1 /***************************************************************************** 2 3 Copyright (c) 2007, 2018, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify it under 6 the terms of the GNU General Public License, version 2.0, as published by the 7 Free Software Foundation. 8 9 This program is also distributed with certain software (including but not 10 limited to OpenSSL) that is licensed under separate terms, as designated in a 11 particular file or component or in included license documentation. The authors 12 of MySQL hereby grant you an additional permission to link the program and 13 your derivative works with the separately licensed software that they have 14 included with MySQL. 15 16 This program is distributed in the hope that it will be useful, but WITHOUT 17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 18 FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, 19 for more details. 20 21 You should have received a copy of the GNU General Public License along with 22 this program; if not, write to the Free Software Foundation, Inc., 23 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 24 25 *****************************************************************************/ 26 27 /** @file include/ha0storage.h 28 Hash storage. 29 Provides a data structure that stores chunks of data in 30 its own storage, avoiding duplicates. 31 32 Created September 22, 2007 Vasil Dimov 33 *******************************************************/ 34 35 #ifndef ha0storage_h 36 #define ha0storage_h 37 38 #include "univ.i" 39 40 /** This value is used by default by ha_storage_create(). More memory 41 is allocated later when/if it is needed. */ 42 #define HA_STORAGE_DEFAULT_HEAP_BYTES 1024 43 44 /** This value is used by default by ha_storage_create(). It is a 45 constant per ha_storage's lifetime. */ 46 #define HA_STORAGE_DEFAULT_HASH_CELLS 4096 47 48 /** Hash storage */ 49 struct ha_storage_t; 50 51 /** Creates a hash storage. If any of the parameters is 0, then a default value 52 is used. 53 @param[in] initial_hash_cells initial number of cells in the hash 54 table 55 @param[in] initial_heap_bytes initial heap's size 56 @return own: hash storage */ 57 UNIV_INLINE 58 ha_storage_t *ha_storage_create(ulint initial_heap_bytes, 59 ulint initial_hash_cells); 60 61 /** Copies data into the storage and returns a pointer to the copy. If the 62 same data chunk is already present, then pointer to it is returned. 63 Data chunks are considered to be equal if len1 == len2 and 64 memcmp(data1, data2, len1) == 0. If "data" is not present (and thus 65 data_len bytes need to be allocated) and the size of storage is going to 66 become more than "memlim" then "data" is not added and NULL is returned. 67 To disable this behavior "memlim" can be set to 0, which stands for 68 "no limit". 69 @return pointer to the copy */ 70 const void *ha_storage_put_memlim( 71 ha_storage_t *storage, /*!< in/out: hash storage */ 72 const void *data, /*!< in: data to store */ 73 ulint data_len, /*!< in: data length */ 74 ulint memlim); /*!< in: memory limit to obey */ 75 76 /** Same as ha_storage_put_memlim() but without memory limit. 77 @param storage in/out: hash storage 78 @param data in: data to store 79 @param data_len in: data length 80 @return pointer to the copy of the string */ 81 #define ha_storage_put(storage, data, data_len) \ 82 ha_storage_put_memlim((storage), (data), (data_len), 0) 83 84 /** Copies string into the storage and returns a pointer to the copy. If the 85 same string is already present, then pointer to it is returned. 86 Strings are considered to be equal if strcmp(str1, str2) == 0. 87 @param storage in/out: hash storage 88 @param str in: string to put 89 @return pointer to the copy of the string */ 90 #define ha_storage_put_str(storage, str) \ 91 ((const char *)ha_storage_put((storage), (str), strlen(str) + 1)) 92 93 /** Copies string into the storage and returns a pointer to the copy obeying 94 a memory limit. 95 If the same string is already present, then pointer to it is returned. 96 Strings are considered to be equal if strcmp(str1, str2) == 0. 97 @param storage in/out: hash storage 98 @param str in: string to put 99 @param memlim in: memory limit to obey 100 @return pointer to the copy of the string */ 101 #define ha_storage_put_str_memlim(storage, str, memlim) \ 102 ((const char *)ha_storage_put_memlim((storage), (str), strlen(str) + 1, \ 103 (memlim))) 104 105 /** Empties a hash storage, freeing memory occupied by data chunks. 106 This invalidates any pointers previously returned by ha_storage_put(). 107 The hash storage is not invalidated itself and can be used again. */ 108 UNIV_INLINE 109 void ha_storage_empty(ha_storage_t **storage); /*!< in/out: hash storage */ 110 111 /** Frees a hash storage and everything it contains, it cannot be used after 112 this call. 113 This invalidates any pointers previously returned by ha_storage_put(). */ 114 UNIV_INLINE 115 void ha_storage_free(ha_storage_t *storage); /*!< in, own: hash storage */ 116 117 /** Gets the size of the memory used by a storage. 118 @return bytes used */ 119 UNIV_INLINE 120 ulint ha_storage_get_size(const ha_storage_t *storage); /*!< in: hash storage */ 121 122 #include "ha0storage.ic" 123 124 #endif /* ha0storage_h */ 125