MySQL 5.1: mysql/src/5.1-dbg/sql/sql_udf.h Source File
mysql/src/5.1-dbg/sql/sql_udf.h

00001 /* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
00002 
00003    This program is free software; you can redistribute it and/or modify
00004    it under the terms of the GNU General Public License as published by
00005    the Free Software Foundation; either version 2 of the License, or
00006    (at your option) any later version.
00007 
00008    This program is distributed in the hope that it will be useful,
00009    but WITHOUT ANY WARRANTY; without even the implied warranty of
00010    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00011    GNU General Public License for more details.
00012 
00013    You should have received a copy of the GNU General Public License
00014    along with this program; if not, write to the Free Software
00015    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
00016 
00017 
00018 /* This file defines structures needed by udf functions */
00019 
00020 #ifdef USE_PRAGMA_INTERFACE
00021 #pragma interface
00022 #endif
00023 
00024 enum Item_udftype {UDFTYPE_FUNCTION=1,UDFTYPE_AGGREGATE};
00025 
00026 typedef void (*Udf_func_clear)(UDF_INIT *, uchar *, uchar *);
00027 typedef void (*Udf_func_add)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *);
00028 typedef void (*Udf_func_deinit)(UDF_INIT*);
00029 typedef my_bool (*Udf_func_init)(UDF_INIT *, UDF_ARGS *,  char *);
00030 typedef void (*Udf_func_any)();
00031 typedef double (*Udf_func_double)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *);
00032 typedef longlong (*Udf_func_longlong)(UDF_INIT *, UDF_ARGS *, uchar *,
00033                                       uchar *);
00034 
00035 typedef struct st_udf_func
00036 {
00037   LEX_STRING name;
00038   Item_result returns;
00039   Item_udftype type;
00040   char *dl;
00041   void *dlhandle;
00042   Udf_func_any func;
00043   Udf_func_init func_init;
00044   Udf_func_deinit func_deinit;
00045   Udf_func_clear func_clear;
00046   Udf_func_add func_add;
00047   ulong usage_count;
00048 } udf_func;
00049 
00050 class Item_result_field;
00051 struct st_table_list;
00052 
00053 class udf_handler :public Sql_alloc
00054 {
00055  protected:
00056   udf_func *u_d;
00057   String *buffers;
00058   UDF_ARGS f_args;
00059   UDF_INIT initid;
00060   char *num_buffer;
00061   uchar error, is_null;
00062   bool initialized;
00063   Item **args;
00064 
00065  public:
00066   table_map used_tables_cache;
00067   bool const_item_cache;
00068   bool not_original;
00069   udf_handler(udf_func *udf_arg) :u_d(udf_arg), buffers(0), error(0),
00070     is_null(0), initialized(0), not_original(0)
00071   {}
00072   ~udf_handler();
00073   const char *name() const { return u_d ? u_d->name.str : "?"; }
00074   Item_result result_type () const
00075   { return u_d  ? u_d->returns : STRING_RESULT;}
00076   bool get_arguments();
00077   bool fix_fields(THD *thd, Item_result_field *item,
00078                   uint arg_count, Item **args);
00079   void cleanup();
00080   double val(my_bool *null_value)
00081   {
00082     is_null= 0;
00083     if (get_arguments())
00084     {
00085       *null_value=1;
00086       return 0.0;
00087     }
00088     Udf_func_double func= (Udf_func_double) u_d->func;
00089     double tmp=func(&initid, &f_args, &is_null, &error);
00090     if (is_null || error)
00091     {
00092       *null_value=1;
00093       return 0.0;
00094     }
00095     *null_value=0;
00096     return tmp;
00097   }
00098   longlong val_int(my_bool *null_value)
00099   {
00100     is_null= 0;
00101     if (get_arguments())
00102     {
00103       *null_value=1;
00104       return LL(0);
00105     }
00106     Udf_func_longlong func= (Udf_func_longlong) u_d->func;
00107     longlong tmp=func(&initid, &f_args, &is_null, &error);
00108     if (is_null || error)
00109     {
00110       *null_value=1;
00111       return LL(0);
00112     }
00113     *null_value=0;
00114     return tmp;
00115   }
00116   my_decimal *val_decimal(my_bool *null_value, my_decimal *dec_buf);
00117   void clear()
00118   {
00119     is_null= 0;
00120     Udf_func_clear func= u_d->func_clear;
00121     func(&initid, &is_null, &error);
00122   }
00123   void add(my_bool *null_value)
00124   {
00125     if (get_arguments())
00126     {
00127       *null_value=1;
00128       return;
00129     }
00130     Udf_func_add func= u_d->func_add;
00131     func(&initid, &f_args, &is_null, &error);
00132     *null_value= (my_bool) (is_null || error);
00133   }
00134   String *val_str(String *str,String *save_str);
00135 };
00136 
00137 
00138 #ifdef HAVE_DLOPEN
00139 void udf_init(void),udf_free(void);
00140 udf_func *find_udf(const char *name, uint len=0,bool mark_used=0);
00141 void free_udf(udf_func *udf);
00142 int mysql_create_function(THD *thd,udf_func *udf);
00143 int mysql_drop_function(THD *thd,const LEX_STRING *name);
00144 #endif
Generated on Sat Sep 9 00:50:21 2006 for MySQL 5.1 by
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