~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  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

 */

/**

  @file

  It is interface module to fixed precision decimals library.

  Most functions use 'uint32_t mask' as parameter, if during operation error

  which fit in this mask is detected then it will be processed automatically

  here. (errors are E_DEC_* constants, see include/decimal.h)

  Most function are just inline wrappers around library calls

*/

#ifndef my_decimal_h

#define my_decimal_h

#ifdef __cplusplus

extern "C" {

#endif

#include <mystrings/decimal.h>

#include <mysys/my_time.h>

#include <drizzled/sql_string.h>

#ifdef __cplusplus

}

#endif

#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 uint32_t my_decimal_size(uint32_t precision, uint32_t scale)

{

  /*

    Always allocate more space to allow library to put decimal point

    where it want

  */

  return decimal_size(precision, scale) + 1;

}

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, DECIMAL_MAX_PRECISION);

  return (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((int)precision, (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, (decimal_t*) d, prec, scale));

}

inline

int my_decimal_set_zero(my_decimal *d)

{

  decimal_make_zero(((decimal_t*) d));

  return 0;

}

inline

bool my_decimal_is_zero(const my_decimal *decimal_value)

{

  return decimal_is_zero((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((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((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((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((decimal_t*)d, &rounded, 0, HALF_UP);

  return check_result(mask, (unsigned_flag ?

			     decimal2uint64_t(&rounded, (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((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,(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, (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((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((decimal_t*)a,(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((decimal_t*)a,(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((decimal_t*)a,(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((decimal_t*)a,(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((decimal_t*)a,(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((decimal_t*) a, (decimal_t*) b);

}

inline

int my_decimal_intg(const my_decimal *a)

{

  return decimal_intg((decimal_t*) a);

}

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

#endif /*my_decimal_h*/