#ifndef SQL_UDF_INCLUDED
#define SQL_UDF_INCLUDED

/* Copyright (c) 2000, 2011, 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,
 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */


/* This file defines structures needed by udf functions */

enum Item_udftype {UDFTYPE_FUNCTION=1,UDFTYPE_AGGREGATE};

typedef void (*Udf_func_clear)(UDF_INIT *, uchar *, uchar *);
typedef void (*Udf_func_add)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *);
typedef void (*Udf_func_deinit)(UDF_INIT*);
typedef my_bool (*Udf_func_init)(UDF_INIT *, UDF_ARGS *, char *);
typedef void (*Udf_func_any)();
typedef double (*Udf_func_double)(UDF_INIT *, UDF_ARGS *, uchar *, uchar *);
typedef longlong (*Udf_func_longlong)(UDF_INIT *, UDF_ARGS *, uchar *,
 uchar *);

typedef struct st_udf_func
{
 LEX_STRING name;
 Item_result returns;
 Item_udftype type;
 char *dl;
 void *dlhandle;
 Udf_func_any func;
 Udf_func_init func_init;
 Udf_func_deinit func_deinit;
 Udf_func_clear func_clear;
 Udf_func_add func_add;
 ulong usage_count;
} udf_func;

class Item_result_field;

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();
 double val(my_bool *null_value)
 {
 is_null= 0;
 if (get_arguments())
 {
 *null_value=1;
 return 0.0;
 }
 Udf_func_double func= (Udf_func_double) 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)
 {
 is_null= 0;
 if (get_arguments())
 {
 *null_value=1;
 return LL(0);
 }
 Udf_func_longlong func= (Udf_func_longlong) 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;
 }
 my_decimal *val_decimal(my_bool *null_value, my_decimal *dec_buf);
 void clear()
 {
 is_null= 0;
 Udf_func_clear func= u_d->func_clear;
 func(&initid, &is_null, &error);
 }
 void add(my_bool *null_value)
 {
 if (get_arguments())
 {
 *null_value=1;
 return;
 }
 Udf_func_add func= 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);
};

#endif /* SQL_UDF_INCLUDED */