1 /***************************************************************************** 2 3 Copyright (c) 2007, 2014, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License, version 2.0, 7 as published by the Free Software Foundation. 8 9 This program is also distributed with certain software (including 10 but not limited to OpenSSL) that is licensed under separate terms, 11 as designated in a particular file or component or in included license 12 documentation. The authors of MySQL hereby grant you an additional 13 permission to link the program and your derivative works with the 14 separately licensed software that they have included with MySQL. 15 16 This program is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 GNU General Public License, version 2.0, 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 Street, Suite 500, Boston, MA 02110-1335 USA 24 25 *****************************************************************************/ 26 27 /**************************************************//** 28 @file include/ha0storage.h 29 Hash storage. 30 Provides a data structure that stores chunks of data in 31 its own storage, avoiding duplicates. 32 33 Created September 22, 2007 Vasil Dimov 34 *******************************************************/ 35 36 #ifndef ha0storage_h 37 #define ha0storage_h 38 39 #include "univ.i" 40 41 /** This value is used by default by ha_storage_create(). More memory 42 is allocated later when/if it is needed. */ 43 #define HA_STORAGE_DEFAULT_HEAP_BYTES 1024 44 45 /** This value is used by default by ha_storage_create(). It is a 46 constant per ha_storage's lifetime. */ 47 #define HA_STORAGE_DEFAULT_HASH_CELLS 4096 48 49 /** Hash storage */ 50 struct ha_storage_t; 51 52 /*******************************************************************//** 53 Creates a hash storage. If any of the parameters is 0, then a default 54 value is used. 55 @return own: hash storage */ 56 UNIV_INLINE 57 ha_storage_t* 58 ha_storage_create( 59 /*==============*/ 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 /*******************************************************************//** 65 Copies data into the storage and returns a pointer to the copy. If the 66 same data chunk is already present, then pointer to it is returned. 67 Data chunks are considered to be equal if len1 == len2 and 68 memcmp(data1, data2, len1) == 0. If "data" is not present (and thus 69 data_len bytes need to be allocated) and the size of storage is going to 70 become more than "memlim" then "data" is not added and NULL is returned. 71 To disable this behavior "memlim" can be set to 0, which stands for 72 "no limit". 73 @return pointer to the copy */ 74 const void* 75 ha_storage_put_memlim( 76 /*==================*/ 77 ha_storage_t* storage, /*!< in/out: hash storage */ 78 const void* data, /*!< in: data to store */ 79 ulint data_len, /*!< in: data length */ 80 ulint memlim); /*!< in: memory limit to obey */ 81 82 /*******************************************************************//** 83 Same as ha_storage_put_memlim() but without memory limit. 84 @param storage in/out: hash storage 85 @param data in: data to store 86 @param data_len in: data length 87 @return pointer to the copy of the string */ 88 #define ha_storage_put(storage, data, data_len) \ 89 ha_storage_put_memlim((storage), (data), (data_len), 0) 90 91 /*******************************************************************//** 92 Copies string into the storage and returns a pointer to the copy. If the 93 same string is already present, then pointer to it is returned. 94 Strings are considered to be equal if strcmp(str1, str2) == 0. 95 @param storage in/out: hash storage 96 @param str in: string to put 97 @return pointer to the copy of the string */ 98 #define ha_storage_put_str(storage, str) \ 99 ((const char*) ha_storage_put((storage), (str), strlen(str) + 1)) 100 101 /*******************************************************************//** 102 Copies string into the storage and returns a pointer to the copy obeying 103 a memory limit. 104 If the same string is already present, then pointer to it is returned. 105 Strings are considered to be equal if strcmp(str1, str2) == 0. 106 @param storage in/out: hash storage 107 @param str in: string to put 108 @param memlim in: memory limit to obey 109 @return pointer to the copy of the string */ 110 #define ha_storage_put_str_memlim(storage, str, memlim) \ 111 ((const char*) ha_storage_put_memlim((storage), (str), \ 112 strlen(str) + 1, (memlim))) 113 114 /*******************************************************************//** 115 Empties a hash storage, freeing memory occupied by data chunks. 116 This invalidates any pointers previously returned by ha_storage_put(). 117 The hash storage is not invalidated itself and can be used again. */ 118 UNIV_INLINE 119 void 120 ha_storage_empty( 121 /*=============*/ 122 ha_storage_t** storage); /*!< in/out: hash storage */ 123 124 /*******************************************************************//** 125 Frees a hash storage and everything it contains, it cannot be used after 126 this call. 127 This invalidates any pointers previously returned by ha_storage_put(). */ 128 UNIV_INLINE 129 void 130 ha_storage_free( 131 /*============*/ 132 ha_storage_t* storage); /*!< in, own: hash storage */ 133 134 /*******************************************************************//** 135 Gets the size of the memory used by a storage. 136 @return bytes used */ 137 UNIV_INLINE 138 ulint 139 ha_storage_get_size( 140 /*================*/ 141 const ha_storage_t* storage); /*!< in: hash storage */ 142 143 #ifndef UNIV_NONINL 144 #include "ha0storage.ic" 145 #endif 146 147 #endif /* ha0storage_h */ 148