sql_udf.h
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:4k
- /* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
- 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; either version 2 of the License, or
- (at your option) any later version.
- 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
- /* This file defines structures needed by udf functions */
- #ifdef USE_PRAGMA_INTERFACE
- #pragma interface
- #endif
- enum Item_udftype {UDFTYPE_FUNCTION=1,UDFTYPE_AGGREGATE};
- typedef struct st_udf_func
- {
- LEX_STRING name;
- Item_result returns;
- Item_udftype type;
- char *dl;
- void *dlhandle;
- void *func;
- void *func_init;
- void *func_deinit;
- void *func_clear;
- void *func_add;
- ulong usage_count;
- } udf_func;
- class Item_result_field;
- struct st_table_list;
- class udf_handler :public Sql_alloc
- {
- protected:
- udf_func *u_d;
- String *buffers;
- UDF_ARGS f_args;
- UDF_INIT initid;
- char *num_buffer;
- uchar error, is_null;
- bool initialized;
- Item **args;
- public:
- table_map used_tables_cache;
- bool const_item_cache;
- bool not_original;
- udf_handler(udf_func *udf_arg) :u_d(udf_arg), buffers(0), error(0),
- is_null(0), initialized(0), not_original(0)
- {}
- ~udf_handler();
- const char *name() const { return u_d ? u_d->name.str : "?"; }
- Item_result result_type () const
- { return u_d ? u_d->returns : STRING_RESULT;}
- bool get_arguments();
- bool fix_fields(THD *thd,struct st_table_list *tlist,Item_result_field *item,
- uint arg_count,Item **args);
- void cleanup();
- double val(my_bool *null_value)
- {
- if (get_arguments())
- {
- *null_value=1;
- return 0.0;
- }
- double (*func)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *)=
- (double (*)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *)) u_d->func;
- double tmp=func(&initid, &f_args, &is_null, &error);
- if (is_null || error)
- {
- *null_value=1;
- return 0.0;
- }
- *null_value=0;
- return tmp;
- }
- longlong val_int(my_bool *null_value)
- {
- if (get_arguments())
- {
- *null_value=1;
- return LL(0);
- }
- longlong (*func)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *)=
- (longlong (*)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *)) u_d->func;
- longlong tmp=func(&initid, &f_args, &is_null, &error);
- if (is_null || error)
- {
- *null_value=1;
- return LL(0);
- }
- *null_value=0;
- return tmp;
- }
- void clear()
- {
- is_null= 0;
- void (*func)(UDF_INIT *, uchar *, uchar *)=
- (void (*)(UDF_INIT *, uchar *, uchar *)) u_d->func_clear;
- func(&initid, &is_null, &error);
- }
- void add(my_bool *null_value)
- {
- if (get_arguments())
- {
- *null_value=1;
- return;
- }
- void (*func)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *)=
- (void (*)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *)) u_d->func_add;
- func(&initid, &f_args, &is_null, &error);
- *null_value= (my_bool) (is_null || error);
- }
- String *val_str(String *str,String *save_str);
- };
- #ifdef HAVE_DLOPEN
- void udf_init(void),udf_free(void);
- udf_func *find_udf(const char *name, uint len=0,bool mark_used=0);
- void free_udf(udf_func *udf);
- int mysql_create_function(THD *thd,udf_func *udf);
- int mysql_drop_function(THD *thd,const LEX_STRING *name);
- #endif