~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 MySQL 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; 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  02110-1301  USA */

#ifndef DRIZZLED_DECIMAL_H

#define DRIZZLED_DECIMAL_H

#include <assert.h>

#include <drizzled/sql_string.h>

#include "drizzled/definitions.h"

#include "drizzled/drizzle_time.h"

namespace drizzled

{

typedef enum

{TRUNCATE=0, HALF_EVEN, HALF_UP, CEILING, FLOOR}

  decimal_round_mode;

typedef int32_t decimal_digit_t;

typedef struct st_decimal_t {

  int    intg, frac, len;

  bool sign;

  decimal_digit_t *buf;

} decimal_t;

int internal_str2dec(char *from, decimal_t *to, char **end,

                     bool fixed);

int decimal2string(const decimal_t *from, char *to, int *to_len,

                   int fixed_precision, int fixed_decimals,

                   char filler);

int decimal2uint64_t(const decimal_t *from, uint64_t *to);

int uint64_t2decimal(const uint64_t from, decimal_t *to);

int decimal2int64_t(const decimal_t *from, int64_t *to);

int int64_t2decimal(const int64_t from, decimal_t *to);

int decimal2double(const decimal_t *from, double *to);

int double2decimal(const double from, decimal_t *to);

int decimal_actual_fraction(decimal_t *from);

int decimal2bin(const decimal_t *from, unsigned char *to, int precision, int scale);

int bin2decimal(const unsigned char *from, decimal_t *to, int precision, int scale);

int decimal_bin_size(int precision, int scale);

int decimal_intg(const decimal_t *from);

int decimal_add(const decimal_t *from1, const decimal_t *from2, decimal_t *to);

int decimal_sub(const decimal_t *from1, const decimal_t *from2, decimal_t *to);

int decimal_cmp(const decimal_t *from1, const decimal_t *from2);

int decimal_mul(const decimal_t *from1, const decimal_t *from2, decimal_t *to);

int decimal_div(const decimal_t *from1, const decimal_t *from2, decimal_t *to,

                int scale_incr);

int decimal_mod(const decimal_t *from1, const decimal_t *from2, decimal_t *to);

int decimal_round(const decimal_t *from, decimal_t *to, int new_scale,

                  decimal_round_mode mode);

int decimal_is_zero(const decimal_t *from);

void max_decimal(int precision, int frac, decimal_t *to);

#define string2decimal(A,B,C) internal_str2dec((A), (B), (C), 0)

/* set a decimal_t to zero */

#define decimal_make_zero(dec)        do {                \

                                        (dec)->buf[0]=0;    \

                                        (dec)->intg=1;      \

                                        (dec)->frac=0;      \

                                        (dec)->sign=0;      \

                                      } while(0)

/*

  returns the length of the buffer to hold string representation

  of the decimal (including decimal dot, possible sign and \0)

*/

#define decimal_string_size(dec) (((dec)->intg ? (dec)->intg : 1) + \

				  (dec)->frac + ((dec)->frac > 0) + 2)

/* negate a decimal */

#define decimal_neg(dec) do { (dec)->sign^=1; } while(0)

/*

  conventions:

    decimal_smth() == 0     -- everything's ok

    decimal_smth() <= 1     -- result is usable, but precision loss is possible

    decimal_smth() <= 2     -- result can be unusable, most significant digits

                               could've been lost

    decimal_smth() >  2     -- no result was generated

*/

#define E_DEC_OK                0

#define E_DEC_TRUNCATED         1

#define E_DEC_OVERFLOW          2

#define E_DEC_DIV_ZERO          4

#define E_DEC_BAD_NUM           8

#define E_DEC_OOM              16

#define E_DEC_ERROR            31

#define E_DEC_FATAL_ERROR      30

#define DECIMAL_LONGLONG_DIGITS 22

#define DECIMAL_LONG_DIGITS 10

#define DECIMAL_LONG3_DIGITS 8

/** maximum length of buffer in our big digits (uint32_t). */

#define DECIMAL_BUFF_LENGTH 9

/* the number of digits that my_decimal can possibly contain */

#define DECIMAL_MAX_POSSIBLE_PRECISION (DECIMAL_BUFF_LENGTH * 9)

/**

  maximum guaranteed precision of number in decimal digits (number of our

  digits * number of decimal digits in one our big digit - number of decimal

  digits in one our big digit decreased by 1 (because we always put decimal

  point on the border of our big digits))

*/

#define DECIMAL_MAX_PRECISION (DECIMAL_MAX_POSSIBLE_PRECISION - 8*2)

#define DECIMAL_MAX_SCALE 30

#define DECIMAL_NOT_SPECIFIED 31

/**

  maximum length of string representation (number of maximum decimal

  digits + 1 position for sign + 1 position for decimal point)

*/

#define DECIMAL_MAX_STR_LENGTH (DECIMAL_MAX_POSSIBLE_PRECISION + 2)

/**

  maximum size of packet length.

*/

#define DECIMAL_MAX_FIELD_SIZE DECIMAL_MAX_PRECISION

inline int my_decimal_int_part(uint32_t precision, uint32_t decimals)

{

  return precision - ((decimals == DECIMAL_NOT_SPECIFIED) ? 0 : decimals);

}

/**

  my_decimal class limits 'decimal_t' type to what we need in MySQL.

  It contains internally all necessary space needed by the instance so

  no extra memory is needed. One should call fix_buffer_pointer() function

  when he moves my_decimal objects in memory.

*/

class my_decimal :public decimal_t

{

  decimal_digit_t buffer[DECIMAL_BUFF_LENGTH];

public:

  void init()

  {

    len= DECIMAL_BUFF_LENGTH;

    buf= buffer;

	#if !defined (HAVE_purify)

		/* Set buffer to 'random' value to find wrong buffer usage */

		for (uint32_t i= 0; i < DECIMAL_BUFF_LENGTH; i++)

		  buffer[i]= i;

	#endif

  }

  my_decimal()

  {

    init();

  }

  void fix_buffer_pointer() { buf= buffer; }

  bool sign() const { return decimal_t::sign; }

  void sign(bool s) { decimal_t::sign= s; }

  uint32_t precision() const { return intg + frac; }

};

int decimal_operation_results(int result);

inline void max_my_decimal(my_decimal *to, int precision, int frac)

{

  assert((precision <= DECIMAL_MAX_PRECISION)&&

              (frac <= DECIMAL_MAX_SCALE));

  max_decimal(precision, frac, (decimal_t*) to);

}

inline void max_internal_decimal(my_decimal *to)

{

  max_my_decimal(to, DECIMAL_MAX_PRECISION, 0);

}

inline int check_result(uint32_t mask, int result)

{

  if (result & mask)

    decimal_operation_results(result);

  return result;

}

inline int check_result_and_overflow(uint32_t mask, int result, my_decimal *val)

{

  if (check_result(mask, result) & E_DEC_OVERFLOW)

  {

    bool sign= val->sign();

    val->fix_buffer_pointer();

    max_internal_decimal(val);

    val->sign(sign);

  }

  return result;

}

inline uint32_t my_decimal_length_to_precision(uint32_t length, uint32_t scale,

                                           bool unsigned_flag)

{

  return (uint32_t) (length - (scale>0 ? 1:0) - (unsigned_flag ? 0:1));

}

inline uint32_t my_decimal_precision_to_length(uint32_t precision, uint8_t scale,

                                             bool unsigned_flag)

{

  set_if_smaller(precision, (uint32_t)DECIMAL_MAX_PRECISION);

  return static_cast<uint32_t>(precision + (scale>0 ? 1:0) + (unsigned_flag ? 0:1));

}

inline

int my_decimal_string_length(const my_decimal *d)

{

  return decimal_string_size(d);

}

inline

int my_decimal_max_length(const my_decimal *d)

{

  /* -1 because we do not count \0 */

  return decimal_string_size(d) - 1;

}

inline

int my_decimal_get_binary_size(uint32_t precision, uint32_t scale)

{

  return decimal_bin_size(static_cast<int>(precision), static_cast<int>(scale));

}

inline

void my_decimal2decimal(const my_decimal *from, my_decimal *to)

{

  *to= *from;

  to->fix_buffer_pointer();

}

int my_decimal2binary(uint32_t mask, const my_decimal *d, unsigned char *bin, int prec,

		      int scale);

inline

int binary2my_decimal(uint32_t mask, const unsigned char *bin, my_decimal *d, int prec,

		      int scale)

{

  return check_result(mask, bin2decimal(bin, static_cast<decimal_t*>(d), prec, scale));

}

inline

int my_decimal_set_zero(my_decimal *d)

{

  decimal_make_zero(static_cast<decimal_t*> (d));

  return 0;

}

inline

bool my_decimal_is_zero(const my_decimal *decimal_value)

{

  return decimal_is_zero(static_cast<const decimal_t*>(decimal_value));

}

inline

int my_decimal_round(uint32_t mask, const my_decimal *from, int scale,

                     bool truncate, my_decimal *to)

{

  return check_result(mask, decimal_round(static_cast<const decimal_t*>(from), to, scale,

                                          (truncate ? TRUNCATE : HALF_UP)));

}

inline

int my_decimal_floor(uint32_t mask, const my_decimal *from, my_decimal *to)

{

  return check_result(mask, decimal_round(static_cast<const decimal_t*>(from), to, 0, FLOOR));

}

inline

int my_decimal_ceiling(uint32_t mask, const my_decimal *from, my_decimal *to)

{

  return check_result(mask, decimal_round(static_cast<const decimal_t*>(from), to, 0, CEILING));

}

int my_decimal2string(uint32_t mask, const my_decimal *d, uint32_t fixed_prec,

                      uint32_t fixed_dec, char filler, String *str);

inline

int my_decimal2int(uint32_t mask, const my_decimal *d, bool unsigned_flag,

                   int64_t *l)

{

  my_decimal rounded;

  /* decimal_round can return only E_DEC_TRUNCATED */

  decimal_round(static_cast<const decimal_t*>(d), &rounded, 0, HALF_UP);

  return check_result(mask, (unsigned_flag ?

			     decimal2uint64_t(&rounded, reinterpret_cast<uint64_t *>(l)) :

			     decimal2int64_t(&rounded, l)));

}

inline

int my_decimal2double(uint32_t, const my_decimal *d, double *result)

{

  /* No need to call check_result as this will always succeed */

  return decimal2double(static_cast<const decimal_t*>(d), result);

}

inline

int str2my_decimal(uint32_t mask, char *str, my_decimal *d, char **end)

{

  return check_result_and_overflow(mask, string2decimal(str, static_cast<decimal_t*>(d),end),

                                   d);

}

int str2my_decimal(uint32_t mask, const char *from, uint32_t length,

                   const CHARSET_INFO * charset, my_decimal *decimal_value);

inline

int string2my_decimal(uint32_t mask, const String *str, my_decimal *d)

{

  return str2my_decimal(mask, str->ptr(), str->length(), str->charset(), d);

}

my_decimal *date2my_decimal(DRIZZLE_TIME *ltime, my_decimal *dec);

inline

int double2my_decimal(uint32_t mask, double val, my_decimal *d)

{

  return check_result_and_overflow(mask, double2decimal(val, static_cast<decimal_t*>(d)), d);

}

inline

int int2my_decimal(uint32_t mask, int64_t i, bool unsigned_flag, my_decimal *d)

{

  return check_result(mask, (unsigned_flag ?

			     uint64_t2decimal(static_cast<uint64_t>(i), d) :

			     int64_t2decimal(i, d)));

}

inline

void my_decimal_neg(decimal_t *arg)

{

  if (decimal_is_zero(arg))

  {

    arg->sign= 0;

    return;

  }

  decimal_neg(arg);

}

inline

int my_decimal_add(uint32_t mask, my_decimal *res, const my_decimal *a,

		   const my_decimal *b)

{

  return check_result_and_overflow(mask,

                                   decimal_add(static_cast<const decimal_t*>(a),

                                               static_cast<const decimal_t*>(b), res),

                                   res);

}

inline

int my_decimal_sub(uint32_t mask, my_decimal *res, const my_decimal *a,

		   const my_decimal *b)

{

  return check_result_and_overflow(mask,

                                   decimal_sub(static_cast<const decimal_t*>(a),

                                               static_cast<const decimal_t*>(b), res),

                                   res);

}

inline

int my_decimal_mul(uint32_t mask, my_decimal *res, const my_decimal *a,

		   const my_decimal *b)

{

  return check_result_and_overflow(mask,

                                   decimal_mul(static_cast<const decimal_t*>(a),

                                               static_cast<const decimal_t*>(b),res),

                                   res);

}

inline

int my_decimal_div(uint32_t mask, my_decimal *res, const my_decimal *a,

		   const my_decimal *b, int div_scale_inc)

{

  return check_result_and_overflow(mask,

                                   decimal_div(static_cast<const decimal_t*>(a),

                                               static_cast<const decimal_t*>(b),res,

                                               div_scale_inc),

                                   res);

}

inline

int my_decimal_mod(uint32_t mask, my_decimal *res, const my_decimal *a,

		   const my_decimal *b)

{

  return check_result_and_overflow(mask,

                                   decimal_mod(static_cast<const decimal_t*>(a),

                                               static_cast<const decimal_t*>(b),res),

                                   res);

}

/**

  @return

    -1 if a<b, 1 if a>b and 0 if a==b

*/

inline

int my_decimal_cmp(const my_decimal *a, const my_decimal *b)

{

  return decimal_cmp(static_cast<const decimal_t*>(a),

                     static_cast<const decimal_t*>(b));

}

inline

int my_decimal_intg(const my_decimal *a)

{

  return decimal_intg(static_cast<const decimal_t*>(a));

}

void my_decimal_trim(uint32_t *precision, uint32_t *scale);

} /* namespace drizzled */

#endif /* DRIZZLED_DECIMAL_H */