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 02110-1301 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
35extern "C" {
36#endif
37
38struct st_mysql_lex_string
39{
40 char *str;
41 size_t length;
42};
43typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
44
45struct st_mysql_const_lex_string
46{
47 const char *str;
48 size_t length;
49};
50typedef struct st_mysql_const_lex_string MYSQL_CONST_LEX_STRING;
51
52extern 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*/
95void *thd_alloc(MYSQL_THD thd, size_t size);
96/**
97 @see thd_alloc()
98*/
99void *thd_calloc(MYSQL_THD thd, size_t size);
100/**
101 @see thd_alloc()
102*/
103char *thd_strdup(MYSQL_THD thd, const char *str);
104/**
105 @see thd_alloc()
106*/
107char *thd_strmake(MYSQL_THD thd, const char *str, size_t size);
108/**
109 @see thd_alloc()
110*/
111void *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*/
126MYSQL_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