MySQL  8.0.26
Source Code Documentation
decimal.h
Go to the documentation of this file.
1 /* Copyright (c) 2000, 2021, Oracle and/or its affiliates.
2 
3  This program is free software; you can redistribute it and/or modify
4  it under the terms of the GNU General Public License, version 2.0,
5  as published by the Free Software Foundation.
6 
7  This program is also distributed with certain software (including
8  but not limited to OpenSSL) that is licensed under separate terms,
9  as designated in a particular file or component or in included license
10  documentation. The authors of MySQL hereby grant you an additional
11  permission to link the program and your derivative works with the
12  separately licensed software that they have included with MySQL.
13 
14  This program is distributed in the hope that it will be useful,
15  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  GNU General Public License, version 2.0, for more details.
18 
19  You should have received a copy of the GNU General Public License
20  along with this program; if not, write to the Free Software
21  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22 
23 #ifndef DECIMAL_INCLUDED
24 #define DECIMAL_INCLUDED
25 
26 #ifndef MYSQL_ABI_CHECK
27 #include <stdlib.h>
28 #endif
29 
30 #include "my_inttypes.h"
31 #include "my_macros.h"
32 
33 typedef enum {
34  TRUNCATE = 0,
38  FLOOR
41 
42 /**
43  intg is the number of *decimal* digits (NOT number of decimal_digit_t's !)
44  before the point
45  frac is the number of decimal digits after the point
46  len is the length of buf (length of allocated space) in decimal_digit_t's,
47  not in bytes
48  sign false means positive, true means negative
49  buf is an array of decimal_digit_t's
50  */
51 struct decimal_t {
52  int intg, frac, len;
53  bool sign;
55 };
56 
57 #ifndef MYSQL_ABI_CHECK
58 void widen_fraction(int new_frac, decimal_t *d);
59 int string2decimal(const char *from, decimal_t *to, const char **end);
60 int decimal2string(const decimal_t *from, char *to, int *to_len,
61  int fixed_precision, int fixed_decimals);
62 inline int decimal2string(const decimal_t *from, char *to, int *to_len) {
63  return decimal2string(from, to, to_len, 0, 0);
64 }
65 int decimal2ulonglong(const decimal_t *from, ulonglong *to);
67 int decimal2longlong(const decimal_t *from, longlong *to);
68 int longlong2decimal(longlong from, decimal_t *to);
69 int decimal2double(const decimal_t *from, double *to);
70 int double2decimal(double from, decimal_t *to);
71 int decimal_actual_fraction(const decimal_t *from);
72 int decimal2bin(const decimal_t *from, uchar *to, int precision, int scale);
73 int bin2decimal(const uchar *from, decimal_t *to, int precision, int scale,
74  bool keep_prec = false);
75 
76 /**
77  Convert decimal to lldiv_t.
78  The integer part is stored in to->quot.
79  The fractional part is multiplied to 10^9 and stored to to->rem.
80  @param from Decimal value
81  @param [out] to lldiv_t value
82  @retval 0 on success
83  @retval !0 in error
84 */
85 int decimal2lldiv_t(const decimal_t *from, lldiv_t *to);
86 
87 /**
88  Convert double value to lldiv_t value.
89  @param nr The double value to convert from.
90  @param [out] lld The lldit_t variable to convert to.
91  @return 0 on success, error code on error.
92 
93  Integer part goes into lld.quot.
94  Fractional part multiplied to 1000000000 (10^9) goes to lld.rem.
95  Typically used in datetime calculations to split seconds
96  and nanoseconds.
97  */
98 int double2lldiv_t(double nr, lldiv_t *lld);
99 int decimal_size(int precision, int scale);
100 int decimal_bin_size(int precision, int scale);
101 
102 int decimal_intg(const decimal_t *from);
103 int decimal_add(const decimal_t *from1, const decimal_t *from2, decimal_t *to);
104 int decimal_sub(const decimal_t *from1, const decimal_t *from2, decimal_t *to);
105 int decimal_cmp(const decimal_t *from1, const decimal_t *from2);
106 int decimal_mul(const decimal_t *from1, const decimal_t *from2, decimal_t *to);
107 int decimal_div(const decimal_t *from1, const decimal_t *from2, decimal_t *to,
108  int scale_incr);
109 int decimal_mod(const decimal_t *from1, const decimal_t *from2, decimal_t *to);
110 int decimal_round(const decimal_t *from, decimal_t *to, int new_scale,
112 int decimal_is_zero(const decimal_t *from);
113 void max_decimal(int precision, int frac, decimal_t *to);
114 int decimal_shift(decimal_t *dec, int shift);
115 
116 /* set a decimal_t to zero */
117 static inline void decimal_make_zero(decimal_t *dec) {
118  dec->buf[0] = 0;
119  dec->intg = 1;
120  dec->frac = 0;
121  dec->sign = false;
122 }
123 
124 /**
125  Returns the length of the buffer to hold string representation
126  of the decimal (including decimal dot, possible sign and \0)
127 */
128 static inline int decimal_string_size(const decimal_t *dec) {
129  return (dec->intg ? dec->intg : 1) + dec->frac + (dec->frac > 0) + 2;
130 }
131 
132 /*
133  conventions:
134 
135  decimal_smth() == 0 -- everything's ok
136  decimal_smth() <= 1 -- result is usable, but precision loss is
137  possible decimal_smth() <= 2 -- result can be unusable, most significant
138  digits could've been lost decimal_smth() > 2 -- no result was generated
139 */
140 
141 #define E_DEC_OK 0
142 #define E_DEC_TRUNCATED 1
143 #define E_DEC_OVERFLOW 2
144 #define E_DEC_DIV_ZERO 4
145 #define E_DEC_BAD_NUM 8
146 #define E_DEC_OOM 16
147 
148 #define E_DEC_ERROR 31
149 #define E_DEC_FATAL_ERROR 30
150 
151 static constexpr int DECIMAL_MAX_SCALE{30};
152 static constexpr int DECIMAL_NOT_SPECIFIED{DECIMAL_MAX_SCALE + 1};
153 
154 #endif // MYSQL_ABI_CHECK
155 
156 #endif // DECIMAL_INCLUDED
int decimal_round(const decimal_t *from, decimal_t *to, int new_scale, decimal_round_mode mode)
Definition: decimal.cc:1627
int decimal_bin_size(int precision, int scale)
Definition: decimal.cc:1605
int decimal2longlong(const decimal_t *from, longlong *to)
Definition: decimal.cc:1148
int ulonglong2decimal(ulonglong from, decimal_t *to)
Definition: decimal.cc:1112
int decimal_mul(const decimal_t *from1, const decimal_t *from2, decimal_t *to)
Definition: decimal.cc:2056
static int decimal_string_size(const decimal_t *dec)
Returns the length of the buffer to hold string representation of the decimal (including decimal dot,...
Definition: decimal.h:128
int bin2decimal(const uchar *from, decimal_t *to, int precision, int scale, bool keep_prec=false)
Definition: decimal.cc:1459
int decimal_mod(const decimal_t *from1, const decimal_t *from2, decimal_t *to)
Definition: decimal.cc:2482
int double2lldiv_t(double nr, lldiv_t *lld)
Convert double value to lldiv_t value.
Definition: decimal.cc:1217
decimal_round_mode
Definition: decimal.h:33
@ CEILING
Definition: decimal.h:37
@ FLOOR
Definition: decimal.h:38
@ HALF_UP
Definition: decimal.h:36
@ TRUNCATE
Definition: decimal.h:34
@ HALF_EVEN
Definition: decimal.h:35
int decimal_add(const decimal_t *from1, const decimal_t *from2, decimal_t *to)
Definition: decimal.cc:2007
int decimal_is_zero(const decimal_t *from)
Definition: decimal.cc:2027
int longlong2decimal(longlong from, decimal_t *to)
Definition: decimal.cc:1117
int decimal_actual_fraction(const decimal_t *from)
Definition: decimal.cc:456
int decimal2lldiv_t(const decimal_t *from, lldiv_t *to)
Convert decimal to lldiv_t.
Definition: decimal.cc:1195
static constexpr int DECIMAL_NOT_SPECIFIED
Definition: decimal.h:152
void max_decimal(int precision, int frac, decimal_t *to)
Definition: decimal.cc:402
int32 decimal_digit_t
Definition: decimal.h:40
int decimal2ulonglong(const decimal_t *from, ulonglong *to)
Definition: decimal.cc:1124
int decimal2bin(const decimal_t *from, uchar *to, int precision, int scale)
Definition: decimal.cc:1324
int decimal_div(const decimal_t *from1, const decimal_t *from2, decimal_t *to, int scale_incr)
Definition: decimal.cc:2450
int decimal_shift(decimal_t *dec, int shift)
Definition: decimal.cc:730
int decimal_size(int precision, int scale)
Definition: decimal.cc:1580
int string2decimal(const char *from, decimal_t *to, const char **end)
Definition: decimal.cc:902
static void decimal_make_zero(decimal_t *dec)
Definition: decimal.h:117
int decimal2double(const decimal_t *from, double *to)
Definition: decimal.cc:1042
int decimal2string(const decimal_t *from, char *to, int *to_len, int fixed_precision, int fixed_decimals)
Definition: decimal.cc:496
int decimal_cmp(const decimal_t *from1, const decimal_t *from2)
Definition: decimal.cc:2017
void widen_fraction(int new_frac, decimal_t *d)
Add zeros behind comma to increase precision of decimal.
Definition: decimal.cc:1015
int decimal_intg(const decimal_t *from)
Returns the number of decimal digits before the decimal point in a decimal_t, with any insignificant ...
Definition: decimal.cc:2001
int double2decimal(double from, decimal_t *to)
Definition: decimal.cc:1071
int decimal_sub(const decimal_t *from1, const decimal_t *from2, decimal_t *to)
Definition: decimal.cc:2012
static constexpr int DECIMAL_MAX_SCALE
Definition: decimal.h:151
static const std::string dec("DECRYPTION")
Some integer typedefs for easier portability.
unsigned long long int ulonglong
Definition: my_inttypes.h:55
unsigned char uchar
Definition: my_inttypes.h:51
long long int longlong
Definition: my_inttypes.h:54
int32_t int32
Definition: my_inttypes.h:65
Some common macros.
Cursor end()
A past-the-end Cursor.
Definition: rules_table_service.cc:188
mode
Definition: file_handle.h:59
intg is the number of decimal digits (NOT number of decimal_digit_t's !) before the point frac is the...
Definition: decimal.h:51
int frac
Definition: decimal.h:52
decimal_digit_t * buf
Definition: decimal.h:54
int intg
Definition: decimal.h:52
bool sign
Definition: decimal.h:53
int len
Definition: decimal.h:52