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mariadb/include/my_time.h
Alexander Barkov b639fe2be1 MDEV-17351 Wrong results for GREATEST,TIMESTAMP,ADDTIME with an out-of-range TIME-alike argument 
Problems:

Functions LEAST() and GREATEST() in TIME context, as well as functions
TIMESTAMP(a,b) and ADDTIME(a,b), returned confusing results when the
input TIME-alike value in a number or in a string was out of the TIME
supported range.

In case of TIMESTAMP(a,b) and ADDTIME(a,b), the second argument
value could get extra unexpected digits. For example, in:
    ADDTIME('2001-01-01 00:00:00', 10000000)  or
    ADDTIME('2001-01-01 00:00:00', '1000:00:00')
the second argument was converted to '838:59:59.999999'
with six fractional digits, which contradicted "decimals"
previously set to 0 in fix_length_and_dec().
These unexpected fractional digits led to confusing function results.

Changes:
1. GREATEST(), LEAST()

   - fixing Item_func_min_max::get_time_native()
   to respect "decimals" set by fix_length_and_dec().
   If a value of some numeric or string time-alike argument
   goes outside of the TIME range and gets limited to '838:59:59.999999',
   it's now right-truncated to the correct fractional precision.

   - fixing, Type_handler_temporal_result::Item_func_min_max_fix_attributes()
   to take into account arguments' time_precision() or datetime_precision(),
   rather than rely on "decimals" calculated by the generic implementation
   in Type_handler::Item_func_min_max_fix_attributes(). This makes
   GREATEST() and LEAST() return better data types, with the same
   fractional precision with what TIMESTAMP(a,b) and ADDTIME(a,b) return
   for the same arguments, and with DATE(a) and TIMESTAMP(a).

2. Item_func_add_time and Item_func_timestamp

   It was semantically wrong to apply the limit of the TIME data type
   to the argument "b", which plays the role of "INTERVAL DAY TO SECOND" here.
   Changing the code to fetch the argument "b" as INTERVAL rather than as TIME.

   The low level routine calc_time_diff() now gets the interval
   value without limiting to '838:59:59.999999', so in these examples:
     ADDTIME('2001-01-01 00:00:00', 10000000)
     ADDTIME('2001-01-01 00:00:00', '1000:00:00')
   calc_time_diff() gets '1000:00:00' as is.  The SQL function result
   now gets limited to the supported result data type range
   (datetime or time) inside calc_time_diff(), which now calculates
   the return value using the real fractional digits that
   came directly from the arguments (without the effect of limiting
   to the TIME range), so the result does not have any unexpected
   fractional digits any more.

   Detailed changes in TIMESTAMP() and ADDTIME():

   - Adding a new class Interval_DDhhmmssff. It's similar to Time, but:
     * does not try to parse datetime format, as it's not needed for
       functions TIMESTAMP() and ADDTIME().
     * does not cut values to '838:59:59.999999'

     The maximum supported Interval_DDhhmmssff's hard limit is
     'UINT_MAX32:59:59.999999'. The maximum used soft limit is:
     - '87649415:59:59.999999'   (in 'hh:mm:ss.ff' format)
     - '3652058 23:59:59.999999' (in 'DD hh:mm:ss.ff' format)
     which is a difference between:
     - TIMESTAMP'0001-01-01 00:00:00' and
     - TIMESTAMP'9999-12-31 23:59:59.999999'
     (the minimum datetime that supports arithmetic, and the
     maximum possible datetime value).

   - Fixing get_date() methods in the classes related to functions
     ADDTIME(a,b) and TIMESTAMP(a,b) to use the new class Interval_DDhhmmssff
     for fetching data from the second argument, instead of get_date().

   - Fixing fix_length_and_dec() methods in the classes related
     to functions ADDTIME(a,b) and TIMESTAMP(a,b) to use
     Interval_DDhhmmssff::fsp(item) instead of item->time_precision()
     to get the fractional precision of the second argument correctly.

   - Splitting the low level function str_to_time() into smaller pieces
     to reuse the code. Adding a new function str_to_DDhhmmssff(), to
     parse "INTERVAL DAY TO SECOND" values.

   After these changes, functions TIMESTAMP() and ADDTIME()
   return much more predictable results, in terms of fractional
   digits, and in terms of the overall result.

   The full ranges of DATETIME and TIME values are now covered by TIMESTAMP()
   and ADDTIME(), so the following can now be calculated:

    SELECT ADDTIME(TIMESTAMP'0001-01-01 00:00:00', '87649415:59:59.999999');
    -> '9999-12-31 23:59:59.999999'

    SELECT TIMESTAMP(DATE'0001-01-01', '87649415:59:59.999999')
    -> '9999-12-31 23:59:59.999999'

    SELECT ADDTIME(TIME'-838:59:59.999999', '1677:59:59.999998');
    -> '838:59:59.999999'
2018-10-08 13:38:01 +04:00

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/*
Copyright (c) 2004, 2011, Oracle and/or its affiliates.
Copyright (c) 2017, Monty Program 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 */
/*
This is a private header of sql-common library, containing
declarations for my_time.c
*/
#ifndef _my_time_h_
#define _my_time_h_
#include "mysql_time.h"
#include "my_decimal_limits.h"
C_MODE_START
extern ulonglong log_10_int[20];
extern uchar days_in_month[];
#define MY_TIME_T_MAX LONG_MAX
#define MY_TIME_T_MIN LONG_MIN
/* Time handling defaults */
#define TIMESTAMP_MAX_YEAR 2038
#define TIMESTAMP_MIN_YEAR (1900 + YY_PART_YEAR - 1)
#define TIMESTAMP_MAX_VALUE INT_MAX32
#define TIMESTAMP_MIN_VALUE 0
/* two-digit years < this are 20..; >= this are 19.. */
#define YY_PART_YEAR 70
/*
check for valid times only if the range of time_t is greater than
the range of my_time_t
*/
#if SIZEOF_TIME_T > 4 || defined(TIME_T_UNSIGNED)
# define IS_TIME_T_VALID_FOR_TIMESTAMP(x) \
((x) <= TIMESTAMP_MAX_VALUE && \
(x) >= TIMESTAMP_MIN_VALUE)
#else
# define IS_TIME_T_VALID_FOR_TIMESTAMP(x) \
((x) >= TIMESTAMP_MIN_VALUE)
#endif
/* Flags to str_to_datetime */
/*
TIME_FUZZY_DATES is used for the result will only be used for comparison
purposes. Conversion is as relaxed as possible.
*/
#define C_TIME_FUZZY_DATES 1U
#define C_TIME_DATETIME_ONLY 2U
#define C_TIME_TIME_ONLY 4U
#define C_TIME_NO_ZERO_IN_DATE (1UL << 23) /* == MODE_NO_ZERO_IN_DATE */
#define C_TIME_NO_ZERO_DATE (1UL << 24) /* == MODE_NO_ZERO_DATE */
#define C_TIME_INVALID_DATES (1UL << 25) /* == MODE_INVALID_DATES */
#define MYSQL_TIME_WARN_TRUNCATED 1U
#define MYSQL_TIME_WARN_OUT_OF_RANGE 2U
#define MYSQL_TIME_NOTE_TRUNCATED 16U
#define MYSQL_TIME_WARN_WARNINGS (MYSQL_TIME_WARN_TRUNCATED|MYSQL_TIME_WARN_OUT_OF_RANGE)
#define MYSQL_TIME_WARN_NOTES (MYSQL_TIME_NOTE_TRUNCATED)
#define MYSQL_TIME_WARN_HAVE_WARNINGS(x) MY_TEST((x) & MYSQL_TIME_WARN_WARNINGS)
#define MYSQL_TIME_WARN_HAVE_NOTES(x) MY_TEST((x) & MYSQL_TIME_WARN_NOTES)
/* Useful constants */
#define SECONDS_IN_24H 86400L
/* Limits for the TIME data type */
#define TIME_MAX_HOUR 838
#define TIME_MAX_MINUTE 59
#define TIME_MAX_SECOND 59
#define TIME_MAX_SECOND_PART 999999
#define TIME_SECOND_PART_FACTOR (TIME_MAX_SECOND_PART+1)
#define TIME_SECOND_PART_DIGITS 6
#define TIME_MAX_VALUE (TIME_MAX_HOUR*10000 + TIME_MAX_MINUTE*100 + TIME_MAX_SECOND)
#define TIME_MAX_VALUE_SECONDS (TIME_MAX_HOUR * 3600L + \
TIME_MAX_MINUTE * 60L + TIME_MAX_SECOND)
/*
Structure to return status from
str_to_datetime(), str_to_time().
*/
typedef struct st_mysql_time_status
{
int warnings;
uint precision;
} MYSQL_TIME_STATUS;
static inline void my_time_status_init(MYSQL_TIME_STATUS *status)
{
status->warnings= 0;
status->precision= 0;
}
my_bool check_date(const MYSQL_TIME *ltime, my_bool not_zero_date,
ulonglong flags, int *was_cut);
my_bool str_to_DDhhmmssff(const char *str, size_t length, MYSQL_TIME *l_time,
ulong max_hour, MYSQL_TIME_STATUS *status);
my_bool str_to_time(const char *str, size_t length, MYSQL_TIME *l_time,
ulonglong flag, MYSQL_TIME_STATUS *status);
my_bool str_to_datetime(const char *str, size_t length, MYSQL_TIME *l_time,
ulonglong flags, MYSQL_TIME_STATUS *status);
longlong number_to_datetime(longlong nr, ulong sec_part, MYSQL_TIME *time_res,
ulonglong flags, int *was_cut);
int number_to_time(my_bool neg, ulonglong nr, ulong sec_part,
MYSQL_TIME *ltime, int *was_cut);
ulonglong TIME_to_ulonglong_datetime(const MYSQL_TIME *);
ulonglong TIME_to_ulonglong_date(const MYSQL_TIME *);
ulonglong TIME_to_ulonglong_time(const MYSQL_TIME *);
ulonglong TIME_to_ulonglong(const MYSQL_TIME *);
double TIME_to_double(const MYSQL_TIME *my_time);
int check_time_range(struct st_mysql_time *my_time, uint dec, int *warning);
my_bool check_datetime_range(const MYSQL_TIME *ltime);
long calc_daynr(uint year,uint month,uint day);
uint calc_days_in_year(uint year);
uint year_2000_handling(uint year);
void my_init_time(void);
/*
Function to check sanity of a TIMESTAMP value
DESCRIPTION
Check if a given MYSQL_TIME value fits in TIMESTAMP range.
This function doesn't make precise check, but rather a rough
estimate.
RETURN VALUES
TRUE The value seems sane
FALSE The MYSQL_TIME value is definitely out of range
*/
static inline my_bool validate_timestamp_range(const MYSQL_TIME *t)
{
if ((t->year > TIMESTAMP_MAX_YEAR || t->year < TIMESTAMP_MIN_YEAR) ||
(t->year == TIMESTAMP_MAX_YEAR && (t->month > 1 || t->day > 19)) ||
(t->year == TIMESTAMP_MIN_YEAR && (t->month < 12 || t->day < 31)))
return FALSE;
return TRUE;
}
/* Can't include mysqld_error.h, it needs mysys to build, thus hardcode 2 error values here. */
#ifndef ER_WARN_DATA_OUT_OF_RANGE
#define ER_WARN_DATA_OUT_OF_RANGE 1264
#define ER_WARN_INVALID_TIMESTAMP 1299
#endif
my_time_t
my_system_gmt_sec(const MYSQL_TIME *t, long *my_timezone, uint *error_code);
void set_zero_time(MYSQL_TIME *tm, enum enum_mysql_timestamp_type time_type);
/*
Required buffer length for my_time_to_str, my_date_to_str,
my_datetime_to_str and TIME_to_string functions. Note, that the
caller is still responsible to check that given TIME structure
has values in valid ranges, otherwise size of the buffer could
be not enough. We also rely on the fact that even wrong values
sent using binary protocol fit in this buffer.
*/
#define MAX_DATE_STRING_REP_LENGTH 30
#define AUTO_SEC_PART_DIGITS DECIMAL_NOT_SPECIFIED
int my_time_to_str(const MYSQL_TIME *l_time, char *to, uint digits);
int my_date_to_str(const MYSQL_TIME *l_time, char *to);
int my_datetime_to_str(const MYSQL_TIME *l_time, char *to, uint digits);
int my_TIME_to_str(const MYSQL_TIME *l_time, char *to, uint digits);
int my_timeval_to_str(const struct timeval *tm, char *to, uint dec);
static inline longlong sec_part_shift(longlong second_part, uint digits)
{
return second_part / (longlong)log_10_int[TIME_SECOND_PART_DIGITS - digits];
}
static inline longlong sec_part_unshift(longlong second_part, uint digits)
{
return second_part * (longlong)log_10_int[TIME_SECOND_PART_DIGITS - digits];
}
/* Date/time rounding and truncation functions */
static inline long my_time_fraction_remainder(long nr, uint decimals)
{
DBUG_ASSERT(decimals <= TIME_SECOND_PART_DIGITS);
return nr % (long) log_10_int[TIME_SECOND_PART_DIGITS - decimals];
}
static inline void my_time_trunc(MYSQL_TIME *ltime, uint decimals)
{
ltime->second_part-= my_time_fraction_remainder(ltime->second_part, decimals);
}
static inline void my_timeval_trunc(struct timeval *tv, uint decimals)
{
tv->tv_usec-= my_time_fraction_remainder(tv->tv_usec, decimals);
}
#define hrtime_to_my_time(X) ((my_time_t)hrtime_to_time(X))
/*
Available interval types used in any statement.
'interval_type' must be sorted so that simple intervals comes first,
ie year, quarter, month, week, day, hour, etc. The order based on
interval size is also important and the intervals should be kept in a
large to smaller order. (get_interval_value() depends on this)
Note: If you change the order of elements in this enum you should fix
order of elements in 'interval_type_to_name' and 'interval_names'
arrays
See also interval_type_to_name, get_interval_value, interval_names, append_interval
*/
enum interval_type
{
INTERVAL_YEAR, INTERVAL_QUARTER, INTERVAL_MONTH, INTERVAL_WEEK, INTERVAL_DAY,
INTERVAL_HOUR, INTERVAL_MINUTE, INTERVAL_SECOND, INTERVAL_MICROSECOND,
INTERVAL_YEAR_MONTH, INTERVAL_DAY_HOUR, INTERVAL_DAY_MINUTE,
INTERVAL_DAY_SECOND, INTERVAL_HOUR_MINUTE, INTERVAL_HOUR_SECOND,
INTERVAL_MINUTE_SECOND, INTERVAL_DAY_MICROSECOND, INTERVAL_HOUR_MICROSECOND,
INTERVAL_MINUTE_MICROSECOND, INTERVAL_SECOND_MICROSECOND, INTERVAL_LAST
};
C_MODE_END
#endif /* _my_time_h_ */
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