1 #ifndef MYSQL_SERVICE_THD_ALLOC_INCLUDED 2 /* Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; version 2 of the License. 7 8 This program is distributed in the hope that it will be useful, 9 but WITHOUT ANY WARRANTY; without even the implied warranty of 10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 GNU General Public License for more details. 12 13 You should have received a copy of the GNU General Public License 14 along with this program; if not, write to the Free Software 15 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ 16 17 /** 18 @file 19 This service provides functions to allocate memory in a connection local 20 memory pool. The memory allocated there will be automatically freed at the 21 end of the statement, don't use it for allocations that should live longer 22 than that. For short living allocations this is more efficient than 23 using my_malloc and friends, and automatic "garbage collection" allows not 24 to think about memory leaks. 25 26 The pool is best for small to medium objects, don't use it for large 27 allocations - they are better served with my_malloc. 28 */ 29 30 #ifndef MYSQL_ABI_CHECK 31 #include <stdlib.h> 32 #endif 33 34 #ifdef __cplusplus 35 extern "C" { 36 #endif 37 38 struct st_mysql_lex_string 39 { 40 char *str; 41 size_t length; 42 }; 43 typedef struct st_mysql_lex_string MYSQL_LEX_STRING; 44 45 struct st_mysql_const_lex_string 46 { 47 const char *str; 48 size_t length; 49 }; 50 typedef struct st_mysql_const_lex_string MYSQL_CONST_LEX_STRING; 51 52 extern struct thd_alloc_service_st { 53 void *(*thd_alloc_func)(MYSQL_THD, size_t); 54 void *(*thd_calloc_func)(MYSQL_THD, size_t); 55 char *(*thd_strdup_func)(MYSQL_THD, const char *); 56 char *(*thd_strmake_func)(MYSQL_THD, const char *, size_t); 57 void *(*thd_memdup_func)(MYSQL_THD, const void*, size_t); 58 MYSQL_CONST_LEX_STRING *(*thd_make_lex_string_func)(MYSQL_THD, 59 MYSQL_CONST_LEX_STRING *, 60 const char *, size_t, int); 61 } *thd_alloc_service; 62 63 #ifdef MYSQL_DYNAMIC_PLUGIN 64 65 #define thd_alloc(thd,size) (thd_alloc_service->thd_alloc_func((thd), (size))) 66 67 #define thd_calloc(thd,size) (thd_alloc_service->thd_calloc_func((thd), (size))) 68 69 #define thd_strdup(thd,str) (thd_alloc_service->thd_strdup_func((thd), (str))) 70 71 #define thd_strmake(thd,str,size) \ 72 (thd_alloc_service->thd_strmake_func((thd), (str), (size))) 73 74 #define thd_memdup(thd,str,size) \ 75 (thd_alloc_service->thd_memdup_func((thd), (str), (size))) 76 77 #define thd_make_lex_string(thd, lex_str, str, size, allocate_lex_string) \ 78 (thd_alloc_service->thd_make_lex_string_func((thd), (lex_str), (str), \ 79 (size), (allocate_lex_string))) 80 81 #else 82 83 /** 84 Allocate memory in the connection's local memory pool 85 86 @details 87 When properly used in place of @c my_malloc(), this can significantly 88 improve concurrency. Don't use this or related functions to allocate 89 large chunks of memory. Use for temporary storage only. The memory 90 will be freed automatically at the end of the statement; no explicit 91 code is required to prevent memory leaks. 92 93 @see alloc_root() 94 */ 95 void *thd_alloc(MYSQL_THD thd, size_t size); 96 /** 97 @see thd_alloc() 98 */ 99 void *thd_calloc(MYSQL_THD thd, size_t size); 100 /** 101 @see thd_alloc() 102 */ 103 char *thd_strdup(MYSQL_THD thd, const char *str); 104 /** 105 @see thd_alloc() 106 */ 107 char *thd_strmake(MYSQL_THD thd, const char *str, size_t size); 108 /** 109 @see thd_alloc() 110 */ 111 void *thd_memdup(MYSQL_THD thd, const void* str, size_t size); 112 113 /** 114 Create a LEX_STRING in this connection's local memory pool 115 116 @param thd user thread connection handle 117 @param lex_str pointer to LEX_STRING object to be initialized 118 @param str initializer to be copied into lex_str 119 @param size length of str, in bytes 120 @param allocate_lex_string flag: if TRUE, allocate new LEX_STRING object, 121 instead of using lex_str value 122 @return NULL on failure, or pointer to the LEX_STRING object 123 124 @see thd_alloc() 125 */ 126 MYSQL_CONST_LEX_STRING 127 *thd_make_lex_string(MYSQL_THD thd, MYSQL_CONST_LEX_STRING *lex_str, 128 const char *str, size_t size, 129 int allocate_lex_string); 130 131 #endif 132 133 #ifdef __cplusplus 134 } 135 #endif 136 137 #define MYSQL_SERVICE_THD_ALLOC_INCLUDED 138 #endif 139 140