my_decimal.h

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/* Copyright (c) 2005, 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, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifndef my_decimal_h
#define my_decimal_h

#if defined(MYSQL_SERVER) || defined(EMBEDDED_LIBRARY)
#include "sql_string.h"                         /* String */
#endif

C_MODE_START
#include <decimal.h>
C_MODE_END

class String;
typedef struct st_mysql_time MYSQL_TIME;

#define DECIMAL_LONGLONG_DIGITS 22
#define DECIMAL_LONG_DIGITS 10
#define DECIMAL_LONG3_DIGITS 8

#define DECIMAL_BUFF_LENGTH 9

/* the number of digits that my_decimal can possibly contain */
#define DECIMAL_MAX_POSSIBLE_PRECISION (DECIMAL_BUFF_LENGTH * 9)


#define DECIMAL_MAX_PRECISION (DECIMAL_MAX_POSSIBLE_PRECISION - 8*2)
#define DECIMAL_MAX_SCALE 30
#define DECIMAL_NOT_SPECIFIED 31

#define DECIMAL_MAX_STR_LENGTH (DECIMAL_MAX_POSSIBLE_PRECISION + 2)

#define DECIMAL_MAX_FIELD_SIZE DECIMAL_MAX_PRECISION


inline uint my_decimal_size(uint precision, uint 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(uint precision, uint decimals)
{
  return precision - ((decimals == DECIMAL_NOT_SPECIFIED) ? 0 : decimals);
}


class my_decimal :public decimal_t
{
  /*
    Several of the routines in strings/decimal.c have had buffer
    overrun/underrun problems. These are *not* caught by valgrind.
    To catch them, we allocate dummy fields around the buffer,
    and test that their values do not change.
   */
#if !defined(DBUG_OFF)
  int foo1;
#endif

  decimal_digit_t buffer[DECIMAL_BUFF_LENGTH];

#if !defined(DBUG_OFF)
  int foo2;
  static const int test_value= 123;
#endif

public:

  my_decimal(const my_decimal &rhs) : decimal_t(rhs)
  {
#if !defined(DBUG_OFF)
    foo1= test_value;
    foo2= test_value;
#endif
    for (uint i= 0; i < DECIMAL_BUFF_LENGTH; i++)
      buffer[i]= rhs.buffer[i];
    fix_buffer_pointer();
  }

  my_decimal& operator=(const my_decimal &rhs)
  {
#if !defined(DBUG_OFF)
    foo1= test_value;
    foo2= test_value;
#endif
    if (this == &rhs)
      return *this;
    decimal_t::operator=(rhs);
    for (uint i= 0; i < DECIMAL_BUFF_LENGTH; i++)
      buffer[i]= rhs.buffer[i];
    fix_buffer_pointer();
    return *this;
  }

  void init()
  {
#if !defined(DBUG_OFF)
    foo1= test_value;
    foo2= test_value;
#endif
    len= DECIMAL_BUFF_LENGTH;
    buf= buffer;
  }

  my_decimal()
  {
    init();
  }
  ~my_decimal()
  {
    sanity_check();
  }

  void sanity_check()
  {
    DBUG_ASSERT(foo1 == test_value);
    DBUG_ASSERT(foo2 == test_value);
  }

  void fix_buffer_pointer() { buf= buffer; }

  bool sign() const { return decimal_t::sign; }
  void sign(bool s) { decimal_t::sign= s; }
  uint precision() const { return intg + frac; }

  void swap(my_decimal &rhs)
  {
    swap_variables(my_decimal, *this, rhs);
  }
};


#ifndef DBUG_OFF
void print_decimal(const my_decimal *dec);
void print_decimal_buff(const my_decimal *dec, const uchar* ptr, int length);
const char *dbug_decimal_as_string(char *buff, const my_decimal *val);
#else
#define dbug_decimal_as_string(A) NULL
#endif

bool str_set_decimal(uint mask, const my_decimal *val, uint fixed_prec,
                     uint fixed_dec, char filler, String *str,
                     const CHARSET_INFO *cs);

extern my_decimal decimal_zero;

#ifndef MYSQL_CLIENT
int decimal_operation_results(int result);
#else
inline int decimal_operation_results(int result)
{
  return result;
}
#endif /*MYSQL_CLIENT*/

inline
void max_my_decimal(my_decimal *to, int precision, int frac)
{
  DBUG_ASSERT((precision <= DECIMAL_MAX_PRECISION)&&
              (frac <= DECIMAL_MAX_SCALE));
  max_decimal(precision, frac, to);
}

inline void max_internal_decimal(my_decimal *to)
{
  max_my_decimal(to, DECIMAL_MAX_PRECISION, 0);
}

inline int check_result(uint mask, int result)
{
  if (result & mask)
    decimal_operation_results(result);
  return result;
}

inline int check_result_and_overflow(uint 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 uint my_decimal_length_to_precision(uint length, uint scale,
                                           bool unsigned_flag)
{
  /* Precision can't be negative thus ignore unsigned_flag when length is 0. */
  DBUG_ASSERT(length || !scale);
  return (uint) (length - (scale>0 ? 1:0) -
                 (unsigned_flag || !length ? 0:1));
}

inline uint32 my_decimal_precision_to_length_no_truncation(uint precision,
                                                           uint8 scale,
                                                           bool unsigned_flag)
{
  /*
    When precision is 0 it means that original length was also 0. Thus
    unsigned_flag is ignored in this case.
  */
  DBUG_ASSERT(precision || !scale);
  return (uint32)(precision + (scale > 0 ? 1 : 0) +
                  (unsigned_flag || !precision ? 0 : 1));
}

inline uint32 my_decimal_precision_to_length(uint precision, uint8 scale,
                                             bool unsigned_flag)
{
  /*
    When precision is 0 it means that original length was also 0. Thus
    unsigned_flag is ignored in this case.
  */
  DBUG_ASSERT(precision || !scale);
  set_if_smaller(precision, DECIMAL_MAX_PRECISION);
  return my_decimal_precision_to_length_no_truncation(precision, scale,
                                                      unsigned_flag);
}

inline
int my_decimal_string_length(const my_decimal *d)
{
  /* length of string representation including terminating '\0' */
  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(uint precision, uint scale)
{
  return decimal_bin_size((int)precision, (int)scale);
}


inline
void my_decimal2decimal(const my_decimal *from, my_decimal *to)
{
  *to= *from;
}


int my_decimal2binary(uint mask, const my_decimal *d, uchar *bin, int prec,
                      int scale);


inline
int binary2my_decimal(uint mask, const uchar *bin, my_decimal *d, int prec,
                      int scale)
{
  return check_result(mask, bin2decimal(bin, d, prec, scale));
}


inline
int my_decimal_set_zero(my_decimal *d)
{
  /*
    We need the up-cast here, since my_decimal has sign() member functions,
    which conflicts with decimal_t::size
    (and decimal_make_zero is a macro, rather than a funcion).
  */
  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(decimal_value);
}


inline
int my_decimal_round(uint mask, const my_decimal *from, int scale,
                     bool truncate, my_decimal *to)
{
  return check_result(mask, decimal_round(from, to, scale,
                                          (truncate ? TRUNCATE : HALF_UP)));
}


inline
int my_decimal_floor(uint mask, const my_decimal *from, my_decimal *to)
{
  return check_result(mask, decimal_round(from, to, 0, FLOOR));
}


inline
int my_decimal_ceiling(uint mask, const my_decimal *from, my_decimal *to)
{
  return check_result(mask, decimal_round(from, to, 0, CEILING));
}


inline bool str_set_decimal(const my_decimal *val, String *str,
                            const CHARSET_INFO *cs)
{
  return str_set_decimal(E_DEC_FATAL_ERROR, val, 0, 0, 0, str, cs);
}

#ifndef MYSQL_CLIENT
class String;
int my_decimal2string(uint mask, const my_decimal *d, uint fixed_prec,
                      uint fixed_dec, char filler, String *str);
#endif

inline
int my_decimal2int(uint mask, const my_decimal *d, my_bool unsigned_flag,
                   longlong *l)
{
  my_decimal rounded;
  /* decimal_round can return only E_DEC_TRUNCATED */
  decimal_round(d, &rounded, 0, HALF_UP);
  return check_result(mask, (unsigned_flag ?
                             decimal2ulonglong(&rounded, (ulonglong *)l) :
                             decimal2longlong(&rounded, l)));
}


inline
int my_decimal2double(uint, const my_decimal *d, double *result)
{
  /* No need to call check_result as this will always succeed */
  return decimal2double(d, result);
}


inline int my_decimal2lldiv_t(uint mask, const my_decimal *d, lldiv_t *to)
{
  return check_result(mask, decimal2lldiv_t(d, to));
}


inline int str2my_decimal(uint mask, const char *str,
                          my_decimal *d, char **end)
{
  return check_result_and_overflow(mask, string2decimal(str, d, end), d);
}


int str2my_decimal(uint mask, const char *from, uint length,
                   const CHARSET_INFO *charset, my_decimal *decimal_value);

#if defined(MYSQL_SERVER) || defined(EMBEDDED_LIBRARY)
inline
int string2my_decimal(uint mask, const String *str, my_decimal *d)
{
  return str2my_decimal(mask, str->ptr(), str->length(), str->charset(), d);
}


my_decimal *date2my_decimal(const MYSQL_TIME *ltime, my_decimal *dec);
my_decimal *time2my_decimal(const MYSQL_TIME *ltime, my_decimal *dec);
my_decimal *timeval2my_decimal(const struct timeval *tm, my_decimal *dec);

#endif /*defined(MYSQL_SERVER) || defined(EMBEDDED_LIBRARY) */

inline
int double2my_decimal(uint mask, double val, my_decimal *d)
{
  return check_result_and_overflow(mask, double2decimal(val, d), d);
}


inline
int int2my_decimal(uint mask, longlong i, my_bool unsigned_flag, my_decimal *d)
{
  return check_result(mask, (unsigned_flag ?
                             ulonglong2decimal((ulonglong)i, d) :
                             longlong2decimal(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(uint mask, my_decimal *res, const my_decimal *a,
                   const my_decimal *b)
{
  return check_result_and_overflow(mask,
                                   decimal_add(a, b, res),
                                   res);
}


inline
int my_decimal_sub(uint mask, my_decimal *res, const my_decimal *a,
                   const my_decimal *b)
{
  return check_result_and_overflow(mask,
                                   decimal_sub(a, b, res),
                                   res);
}


inline
int my_decimal_mul(uint mask, my_decimal *res, const my_decimal *a,
                   const my_decimal *b)
{
  return check_result_and_overflow(mask,
                                   decimal_mul(a, b, res),
                                   res);
}


inline
int my_decimal_div(uint mask, my_decimal *res, const my_decimal *a,
                   const my_decimal *b, int div_scale_inc)
{
  return check_result_and_overflow(mask,
                                   decimal_div(a, b, res, div_scale_inc),
                                   res);
}


inline
int my_decimal_mod(uint mask, my_decimal *res, const my_decimal *a,
                   const my_decimal *b)
{
  return check_result_and_overflow(mask,
                                   decimal_mod(a, b, res),
                                   res);
}


inline
int my_decimal_cmp(const my_decimal *a, const my_decimal *b)
{
  return decimal_cmp(a, b);
}


inline
int my_decimal_intg(const my_decimal *a)
{
  return decimal_intg(a);
}


void my_decimal_trim(ulong *precision, uint *scale);


#endif /*my_decimal_h*/