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Diffstat (limited to 'mysql/mysql/service_thd_alloc.h')
| -rw-r--r-- | mysql/mysql/service_thd_alloc.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/mysql/mysql/service_thd_alloc.h b/mysql/mysql/service_thd_alloc.h new file mode 100644 index 0000000..5a89026 --- /dev/null +++ b/mysql/mysql/service_thd_alloc.h @@ -0,0 +1,132 @@ +#ifndef MYSQL_SERVICE_THD_ALLOC_INCLUDED +/* Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + +/** + @file + This service provdes functions to allocate memory in a connection local + memory pool. The memory allocated there will be automatically freed at the + end of the statement, don't use it for allocations that should live longer + than that. For short living allocations this is more efficient than + using my_malloc and friends, and automatic "garbage collection" allows not + to think about memory leaks. + + The pool is best for small to medium objects, don't use it for large + allocations - they are better served with my_malloc. +*/ + +#ifndef MYSQL_ABI_CHECK +#include <stdlib.h> +#endif + +#ifdef __cplusplus +class THD; +#define MYSQL_THD THD* +#else +#define MYSQL_THD void* +#endif + +#ifdef __cplusplus +extern "C" { +#endif + +#include <mysql/mysql_lex_string.h> + +extern struct thd_alloc_service_st { + void *(*thd_alloc_func)(MYSQL_THD, size_t); + void *(*thd_calloc_func)(MYSQL_THD, size_t); + char *(*thd_strdup_func)(MYSQL_THD, const char *); + char *(*thd_strmake_func)(MYSQL_THD, const char *, size_t); + void *(*thd_memdup_func)(MYSQL_THD, const void*, size_t); + MYSQL_LEX_STRING *(*thd_make_lex_string_func)(MYSQL_THD, MYSQL_LEX_STRING *, + const char *, size_t, int); +} *thd_alloc_service; + +#ifdef MYSQL_DYNAMIC_PLUGIN + +#define thd_alloc(thd,size) (thd_alloc_service->thd_alloc_func((thd), (size))) + +#define thd_calloc(thd,size) (thd_alloc_service->thd_calloc_func((thd), (size))) + +#define thd_strdup(thd,str) (thd_alloc_service->thd_strdup_func((thd), (str))) + +#define thd_strmake(thd,str,size) \ + (thd_alloc_service->thd_strmake_func((thd), (str), (size))) + +#define thd_memdup(thd,str,size) \ + (thd_alloc_service->thd_memdup_func((thd), (str), (size))) + +#define thd_make_lex_string(thd, lex_str, str, size, allocate_lex_string) \ + (thd_alloc_service->thd_make_lex_string_func((thd), (lex_str), (str), \ + (size), (allocate_lex_string))) + +#else + +/** + Allocate memory in the connection's local memory pool + + @details + When properly used in place of @c my_malloc(), this can significantly + improve concurrency. Don't use this or related functions to allocate + large chunks of memory. Use for temporary storage only. The memory + will be freed automatically at the end of the statement; no explicit + code is required to prevent memory leaks. + + @see alloc_root() +*/ +void *thd_alloc(MYSQL_THD thd, size_t size); +/** + @see thd_alloc() +*/ +void *thd_calloc(MYSQL_THD thd, size_t size); +/** + @see thd_alloc() +*/ +char *thd_strdup(MYSQL_THD thd, const char *str); +/** + @see thd_alloc() +*/ +char *thd_strmake(MYSQL_THD thd, const char *str, size_t size); +/** + @see thd_alloc() +*/ +void *thd_memdup(MYSQL_THD thd, const void* str, size_t size); + +/** + Create a LEX_STRING in this connection's local memory pool + + @param thd user thread connection handle + @param lex_str pointer to LEX_STRING object to be initialized + @param str initializer to be copied into lex_str + @param size length of str, in bytes + @param allocate_lex_string flag: if TRUE, allocate new LEX_STRING object, + instead of using lex_str value + @return NULL on failure, or pointer to the LEX_STRING object + + @see thd_alloc() +*/ +MYSQL_LEX_STRING *thd_make_lex_string(MYSQL_THD thd, MYSQL_LEX_STRING *lex_str, + const char *str, size_t size, + int allocate_lex_string); + +#endif + +#ifdef __cplusplus +} +#endif + +#define MYSQL_SERVICE_THD_ALLOC_INCLUDED +#endif + |