1 files changed, 139 insertions, 0 deletions
diff --git a/include/mysql/service_thd_alloc.h b/include/mysql/service_thd_alloc.h
new file mode 100644
index 00000000..0be4687b
--- /dev/null
+++ b/include/mysql/service_thd_alloc.h
@@ -0,0 +1,139 @@
+#ifndef MYSQL_SERVICE_THD_ALLOC_INCLUDED
+/* Copyright (c) 2009, 2010, 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 02110-1335  USA */
+
+/**
+  @file
+  This service provides 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
+extern "C" {
+#endif
+
+struct st_mysql_lex_string
+{
+  char *str;
+  size_t length;
+};
+typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+
+struct st_mysql_const_lex_string
+{
+  const char *str;
+  size_t length;
+};
+typedef struct st_mysql_const_lex_string MYSQL_CONST_LEX_STRING;
+
+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_CONST_LEX_STRING *(*thd_make_lex_string_func)(MYSQL_THD,
+                                        MYSQL_CONST_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_CONST_LEX_STRING
+*thd_make_lex_string(MYSQL_THD thd, MYSQL_CONST_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
+