1 /***************************************************************************** 2 3 Copyright (c) 2007, 2016, 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 as published by the Free Software 7 Foundation; version 2 of the License. 8 9 This program is distributed in the hope that it will be useful, but WITHOUT 10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 11 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 12 13 You should have received a copy of the GNU General Public License along with 14 this program; if not, write to the Free Software Foundation, Inc., 15 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA 16 17 *****************************************************************************/ 18 19 /**************************************************//** 20 @file include/ha0storage.h 21 Hash storage. 22 Provides a data structure that stores chunks of data in 23 its own storage, avoiding duplicates. 24 25 Created September 22, 2007 Vasil Dimov 26 *******************************************************/ 27 28 #ifndef ha0storage_h 29 #define ha0storage_h 30 31 #include "univ.i" 32 33 /** This value is used by default by ha_storage_create(). More memory 34 is allocated later when/if it is needed. */ 35 #define HA_STORAGE_DEFAULT_HEAP_BYTES 1024 36 37 /** This value is used by default by ha_storage_create(). It is a 38 constant per ha_storage's lifetime. */ 39 #define HA_STORAGE_DEFAULT_HASH_CELLS 4096 40 41 /** Hash storage */ 42 struct ha_storage_t; 43 44 /*******************************************************************//** 45 Creates a hash storage. If any of the parameters is 0, then a default 46 value is used. 47 @return own: hash storage */ 48 UNIV_INLINE 49 ha_storage_t* 50 ha_storage_create( 51 /*==============*/ 52 ulint initial_heap_bytes, /*!< in: initial heap's size */ 53 ulint initial_hash_cells); /*!< in: initial number of cells 54 in the hash table */ 55 56 /*******************************************************************//** 57 Copies data into the storage and returns a pointer to the copy. If the 58 same data chunk is already present, then pointer to it is returned. 59 Data chunks are considered to be equal if len1 == len2 and 60 memcmp(data1, data2, len1) == 0. If "data" is not present (and thus 61 data_len bytes need to be allocated) and the size of storage is going to 62 become more than "memlim" then "data" is not added and NULL is returned. 63 To disable this behavior "memlim" can be set to 0, which stands for 64 "no limit". 65 @return pointer to the copy */ 66 const void* 67 ha_storage_put_memlim( 68 /*==================*/ 69 ha_storage_t* storage, /*!< in/out: hash storage */ 70 const void* data, /*!< in: data to store */ 71 ulint data_len, /*!< in: data length */ 72 ulint memlim); /*!< in: memory limit to obey */ 73 74 /*******************************************************************//** 75 Same as ha_storage_put_memlim() but without memory limit. 76 @param storage in/out: hash storage 77 @param data in: data to store 78 @param data_len in: data length 79 @return pointer to the copy of the string */ 80 #define ha_storage_put(storage, data, data_len) \ 81 ha_storage_put_memlim((storage), (data), (data_len), 0) 82 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 /*******************************************************************//** 94 Copies string into the storage and returns a pointer to the copy obeying 95 a memory limit. 96 If the same string is already present, then pointer to it is returned. 97 Strings are considered to be equal if strcmp(str1, str2) == 0. 98 @param storage in/out: hash storage 99 @param str in: string to put 100 @param memlim in: memory limit to obey 101 @return pointer to the copy of the string */ 102 #define ha_storage_put_str_memlim(storage, str, memlim) \ 103 ((const char*) ha_storage_put_memlim((storage), (str), \ 104 strlen(str) + 1, (memlim))) 105 106 /*******************************************************************//** 107 Empties a hash storage, freeing memory occupied by data chunks. 108 This invalidates any pointers previously returned by ha_storage_put(). 109 The hash storage is not invalidated itself and can be used again. */ 110 UNIV_INLINE 111 void 112 ha_storage_empty( 113 /*=============*/ 114 ha_storage_t** storage); /*!< in/out: hash storage */ 115 116 /*******************************************************************//** 117 Frees a hash storage and everything it contains, it cannot be used after 118 this call. 119 This invalidates any pointers previously returned by ha_storage_put(). */ 120 UNIV_INLINE 121 void 122 ha_storage_free( 123 /*============*/ 124 ha_storage_t* storage); /*!< in, own: hash storage */ 125 126 /*******************************************************************//** 127 Gets the size of the memory used by a storage. 128 @return bytes used */ 129 UNIV_INLINE 130 ulint 131 ha_storage_get_size( 132 /*================*/ 133 const ha_storage_t* storage); /*!< in: hash storage */ 134 135 #include "ha0storage.inl" 136 137 #endif /* ha0storage_h */ 138