/* Copyright (C) 2004 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or (at your option) any later version. 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <my_time.h> #include <m_string.h> #include <m_ctype.h> /* Windows version of localtime_r() is declared in my_ptrhead.h */ #include <my_pthread.h> ulonglong log_10_int[20]= { 1, 10, 100, 1000, 10000UL, 100000UL, 1000000UL, 10000000UL, ULL(100000000), ULL(1000000000), ULL(10000000000), ULL(100000000000), ULL(1000000000000), ULL(10000000000000), ULL(100000000000000), ULL(1000000000000000), ULL(10000000000000000), ULL(100000000000000000), ULL(1000000000000000000), ULL(10000000000000000000) }; /* Position for YYYY-DD-MM HH-MM-DD.FFFFFF AM in default format */ static uchar internal_format_positions[]= {0, 1, 2, 3, 4, 5, 6, (uchar) 255}; static char time_separator=':'; static ulong const days_at_timestart=719528; /* daynr at 1970.01.01 */ uchar days_in_month[]= {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31, 0}; /* Offset of system time zone from UTC in seconds used to speed up work of my_system_gmt_sec() function. */ static long my_time_zone=0; /* Convert a timestamp string to a MYSQL_TIME value. SYNOPSIS str_to_datetime() str String to parse length Length of string l_time Date is stored here flags Bitmap of following items TIME_FUZZY_DATE Set if we should allow partial dates TIME_DATETIME_ONLY Set if we only allow full datetimes. was_cut Set to 1 if value was cut during conversion or to 0 otherwise. DESCRIPTION At least the following formats are recogniced (based on number of digits) YYMMDD, YYYYMMDD, YYMMDDHHMMSS, YYYYMMDDHHMMSS YY-MM-DD, YYYY-MM-DD, YY-MM-DD HH.MM.SS YYYYMMDDTHHMMSS where T is a the character T (ISO8601) Also dates where all parts are zero are allowed The second part may have an optional .###### fraction part. NOTES This function should work with a format position vector as long as the following things holds: - All date are kept together and all time parts are kept together - Date and time parts must be separated by blank - Second fractions must come after second part and be separated by a '.'. (The second fractions are optional) - AM/PM must come after second fractions (or after seconds if no fractions) - Year must always been specified. - If time is before date, then we will use datetime format only if the argument consist of two parts, separated by space. Otherwise we will assume the argument is a date. - The hour part must be specified in hour-minute-second order. RETURN VALUES MYSQL_TIMESTAMP_NONE String wasn't a timestamp, like [DD [HH:[MM:[SS]]]].fraction. l_time is not changed. MYSQL_TIMESTAMP_DATE DATE string (YY MM and DD parts ok) MYSQL_TIMESTAMP_DATETIME Full timestamp MYSQL_TIMESTAMP_ERROR Timestamp with wrong values. All elements in l_time is set to 0 */ #define MAX_DATE_PARTS 8 enum enum_mysql_timestamp_type str_to_datetime(const char *str, uint length, MYSQL_TIME *l_time, uint flags, int *was_cut) { uint field_length, year_length, digits, i, number_of_fields; uint date[MAX_DATE_PARTS], date_len[MAX_DATE_PARTS]; uint add_hours= 0, start_loop; ulong not_zero_date, allow_space; bool is_internal_format; const char *pos, *last_field_pos; const char *end=str+length; const uchar *format_position; bool found_delimitier= 0, found_space= 0; uint frac_pos, frac_len; DBUG_ENTER("str_to_datetime"); DBUG_PRINT("ENTER",("str: %.*s",length,str)); LINT_INIT(field_length); LINT_INIT(year_length); LINT_INIT(last_field_pos); *was_cut= 0; /* Skip space at start */ for (; str != end && my_isspace(&my_charset_latin1, *str) ; str++) ; if (str == end || ! my_isdigit(&my_charset_latin1, *str)) { *was_cut= 1; DBUG_RETURN(MYSQL_TIMESTAMP_NONE); } is_internal_format= 0; /* This has to be changed if want to activate different timestamp formats */ format_position= internal_format_positions; /* Calculate number of digits in first part. If length= 8 or >= 14 then year is of format YYYY. (YYYY-MM-DD, YYYYMMDD, YYYYYMMDDHHMMSS) */ for (pos=str; pos != end && (my_isdigit(&my_charset_latin1,*pos) || *pos == 'T'); pos++) ; digits= (uint) (pos-str); start_loop= 0; /* Start of scan loop */ date_len[format_position[0]]= 0; /* Length of year field */ if (pos == end) { /* Found date in internal format (only numbers like YYYYMMDD) */ year_length= (digits == 4 || digits == 8 || digits >= 14) ? 4 : 2; field_length= year_length; is_internal_format= 1; format_position= internal_format_positions; } else { if (format_position[0] >= 3) /* If year is after HHMMDD */ { /* If year is not in first part then we have to determinate if we got a date field or a datetime field. We do this by checking if there is two numbers separated by space in the input. */ while (pos < end && !my_isspace(&my_charset_latin1, *pos)) pos++; while (pos < end && !my_isdigit(&my_charset_latin1, *pos)) pos++; if (pos == end) { if (flags & TIME_DATETIME_ONLY) { *was_cut= 1; DBUG_RETURN(MYSQL_TIMESTAMP_NONE); /* Can't be a full datetime */ } /* Date field. Set hour, minutes and seconds to 0 */ date[0]= date[1]= date[2]= date[3]= date[4]= 0; start_loop= 5; /* Start with first date part */ } } field_length= format_position[0] == 0 ? 4 : 2; } /* Only allow space in the first "part" of the datetime field and: - after days, part seconds - before and after AM/PM (handled by code later) 2003-03-03 20:00:20 AM 20:00:20.000000 AM 03-03-2000 */ i= max((uint) format_position[0], (uint) format_position[1]); set_if_bigger(i, (uint) format_position[2]); allow_space= ((1 << i) | (1 << format_position[6])); allow_space&= (1 | 2 | 4 | 8); not_zero_date= 0; for (i = start_loop; i < MAX_DATE_PARTS-1 && str != end && my_isdigit(&my_charset_latin1,*str); i++) { const char *start= str; ulong tmp_value= (uint) (uchar) (*str++ - '0'); while (str != end && my_isdigit(&my_charset_latin1,str[0]) && (!is_internal_format || --field_length)) { tmp_value=tmp_value*10 + (ulong) (uchar) (*str - '0'); str++; } date_len[i]= (uint) (str - start); if (tmp_value > 999999) /* Impossible date part */ { *was_cut= 1; DBUG_RETURN(MYSQL_TIMESTAMP_NONE); } date[i]=tmp_value; not_zero_date|= tmp_value; /* Length of next field */ field_length= format_position[i+1] == 0 ? 4 : 2; if ((last_field_pos= str) == end) { i++; /* Register last found part */ break; } /* Allow a 'T' after day to allow CCYYMMDDT type of fields */ if (i == format_position[2] && *str == 'T') { str++; /* ISO8601: CCYYMMDDThhmmss */ continue; } if (i == format_position[5]) /* Seconds */ { if (*str == '.') /* Followed by part seconds */ { str++; field_length= 6; /* 6 digits */ } continue; /* No part seconds */ date[++i]= 0; } while (str != end && (my_ispunct(&my_charset_latin1,*str) || my_isspace(&my_charset_latin1,*str))) { if (my_isspace(&my_charset_latin1,*str)) { if (!(allow_space & (1 << i))) { *was_cut= 1; DBUG_RETURN(MYSQL_TIMESTAMP_NONE); } found_space= 1; } str++; found_delimitier= 1; /* Should be a 'normal' date */ } /* Check if next position is AM/PM */ if (i == format_position[6]) /* Seconds, time for AM/PM */ { i++; /* Skip AM/PM part */ if (format_position[7] != 255) /* If using AM/PM */ { if (str+2 <= end && (str[1] == 'M' || str[1] == 'm')) { if (str[0] == 'p' || str[0] == 'P') add_hours= 12; else if (str[0] != 'a' || str[0] != 'A') continue; /* Not AM/PM */ str+= 2; /* Skip AM/PM */ /* Skip space after AM/PM */ while (str != end && my_isspace(&my_charset_latin1,*str)) str++; } } } last_field_pos= str; } if (found_delimitier && !found_space && (flags & TIME_DATETIME_ONLY)) { *was_cut= 1; DBUG_RETURN(MYSQL_TIMESTAMP_NONE); /* Can't be a datetime */ } str= last_field_pos; number_of_fields= i - start_loop; while (i < MAX_DATE_PARTS) { date_len[i]= 0; date[i++]= 0; } if (!is_internal_format) { year_length= date_len[(uint) format_position[0]]; if (!year_length) /* Year must be specified */ { *was_cut= 1; DBUG_RETURN(MYSQL_TIMESTAMP_NONE); } l_time->year= date[(uint) format_position[0]]; l_time->month= date[(uint) format_position[1]]; l_time->day= date[(uint) format_position[2]]; l_time->hour= date[(uint) format_position[3]]; l_time->minute= date[(uint) format_position[4]]; l_time->second= date[(uint) format_position[5]]; frac_pos= (uint) format_position[6]; frac_len= date_len[frac_pos]; if (frac_len < 6) date[frac_pos]*= (uint) log_10_int[6 - frac_len]; l_time->second_part= date[frac_pos]; if (format_position[7] != (uchar) 255) { if (l_time->hour > 12) { *was_cut= 1; goto err; } l_time->hour= l_time->hour%12 + add_hours; } } else { l_time->year= date[0]; l_time->month= date[1]; l_time->day= date[2]; l_time->hour= date[3]; l_time->minute= date[4]; l_time->second= date[5]; if (date_len[6] < 6) date[6]*= (uint) log_10_int[6 - date_len[6]]; l_time->second_part=date[6]; } l_time->neg= 0; if (year_length == 2 && not_zero_date) l_time->year+= (l_time->year < YY_PART_YEAR ? 2000 : 1900); if (number_of_fields < 3 || l_time->year > 9999 || l_time->month > 12 || l_time->day > 31 || l_time->hour > 23 || l_time->minute > 59 || l_time->second > 59 || (!(flags & TIME_FUZZY_DATE) && (l_time->month == 0 || l_time->day == 0))) { /* Only give warning for a zero date if there is some garbage after */ if (!not_zero_date) /* If zero date */ { for (; str != end ; str++) { if (!my_isspace(&my_charset_latin1, *str)) { not_zero_date= 1; /* Give warning */ break; } } } if (not_zero_date) *was_cut= 1; goto err; } l_time->time_type= (number_of_fields <= 3 ? MYSQL_TIMESTAMP_DATE : MYSQL_TIMESTAMP_DATETIME); for (; str != end ; str++) { if (!my_isspace(&my_charset_latin1,*str)) { *was_cut= 1; break; } } DBUG_RETURN(l_time->time_type= (number_of_fields <= 3 ? MYSQL_TIMESTAMP_DATE : MYSQL_TIMESTAMP_DATETIME)); err: bzero((char*) l_time, sizeof(*l_time)); DBUG_RETURN(MYSQL_TIMESTAMP_ERROR); } /* Convert a time string to a TIME struct. SYNOPSIS str_to_time() str A string in full TIMESTAMP format or [-] DAYS [H]H:MM:SS, [H]H:MM:SS, [M]M:SS, [H]HMMSS, [M]MSS or [S]S There may be an optional [.second_part] after seconds length Length of str l_time Store result here was_cut Set to 1 if value was cut during conversion or to 0 otherwise. NOTES Because of the extra days argument, this function can only work with times where the time arguments are in the above order. RETURN 0 ok 1 error */ bool str_to_time(const char *str, uint length, MYSQL_TIME *l_time, int *was_cut) { long date[5],value; const char *end=str+length, *end_of_days; bool found_days,found_hours; uint state; l_time->neg=0; *was_cut= 0; for (; str != end && my_isspace(&my_charset_latin1,*str) ; str++) length--; if (str != end && *str == '-') { l_time->neg=1; str++; length--; } if (str == end) return 1; /* Check first if this is a full TIMESTAMP */ if (length >= 12) { /* Probably full timestamp */ enum enum_mysql_timestamp_type res= str_to_datetime(str, length, l_time, (TIME_FUZZY_DATE | TIME_DATETIME_ONLY), was_cut); if ((int) res >= (int) MYSQL_TIMESTAMP_ERROR) return res == MYSQL_TIMESTAMP_ERROR; /* We need to restore was_cut flag since str_to_datetime can modify it */ *was_cut= 0; } /* Not a timestamp. Try to get this as a DAYS_TO_SECOND string */ for (value=0; str != end && my_isdigit(&my_charset_latin1,*str) ; str++) value=value*10L + (long) (*str - '0'); /* Skip all space after 'days' */ end_of_days= str; for (; str != end && my_isspace(&my_charset_latin1, str[0]) ; str++) ; LINT_INIT(state); found_days=found_hours=0; if ((uint) (end-str) > 1 && str != end_of_days && my_isdigit(&my_charset_latin1, *str)) { /* Found days part */ date[0]= value; state= 1; /* Assume next is hours */ found_days= 1; } else if ((end-str) > 1 && *str == time_separator && my_isdigit(&my_charset_latin1, str[1])) { date[0]=0; /* Assume we found hours */ date[1]=value; state=2; found_hours=1; str++; /* skip ':' */ } else { /* String given as one number; assume HHMMSS format */ date[0]= 0; date[1]= value/10000; date[2]= value/100 % 100; date[3]= value % 100; state=4; goto fractional; } /* Read hours, minutes and seconds */ for (;;) { for (value=0; str != end && my_isdigit(&my_charset_latin1,*str) ; str++) value=value*10L + (long) (*str - '0'); date[state++]=value; if (state == 4 || (end-str) < 2 || *str != time_separator || !my_isdigit(&my_charset_latin1,str[1])) break; str++; /* Skip time_separator (':') */ } if (state != 4) { /* Not HH:MM:SS */ /* Fix the date to assume that seconds was given */ if (!found_hours && !found_days) { bmove_upp((char*) (date+4), (char*) (date+state), sizeof(long)*(state-1)); bzero((char*) date, sizeof(long)*(4-state)); } else bzero((char*) (date+state), sizeof(long)*(4-state)); } fractional: /* Get fractional second part */ if ((end-str) >= 2 && *str == '.' && my_isdigit(&my_charset_latin1,str[1])) { int field_length= 5; str++; value=(uint) (uchar) (*str - '0'); while (++str != end && my_isdigit(&my_charset_latin1, *str)) { if (field_length-- > 0) value= value*10 + (uint) (uchar) (*str - '0'); } if (field_length > 0) value*= (long) log_10_int[field_length]; else if (field_length < 0) *was_cut= 1; date[4]=value; } else date[4]=0; /* Check for exponent part: E<gigit> | E<sign><digit> */ /* (may occur as result of %g formatting of time value) */ if ((end - str) > 1 && (*str == 'e' || *str == 'E') && (my_isdigit(&my_charset_latin1, str[1]) || ((str[1] == '-' || str[1] == '+') && (end - str) > 2 && my_isdigit(&my_charset_latin1, str[2])))) { *was_cut= 1; return 1; } if (internal_format_positions[7] != 255) { /* Read a possible AM/PM */ while (str != end && my_isspace(&my_charset_latin1, *str)) str++; if (str+2 <= end && (str[1] == 'M' || str[1] == 'm')) { if (str[0] == 'p' || str[0] == 'P') { str+= 2; date[1]= date[1]%12 + 12; } else if (str[0] == 'a' || str[0] == 'A') str+=2; } } /* Some simple checks */ if (date[2] >= 60 || date[3] >= 60) { *was_cut= 1; return 1; } l_time->year= 0; /* For protocol::store_time */ l_time->month= 0; l_time->day= date[0]; l_time->hour= date[1]; l_time->minute= date[2]; l_time->second= date[3]; l_time->second_part= date[4]; l_time->time_type= MYSQL_TIMESTAMP_TIME; /* Check if there is garbage at end of the TIME specification */ if (str != end) { do { if (!my_isspace(&my_charset_latin1,*str)) { *was_cut= 1; break; } } while (++str != end); } return 0; } /* Prepare offset of system time zone from UTC for my_system_gmt_sec() func. SYNOPSIS init_time() */ void init_time(void) { time_t seconds; struct tm *l_time,tm_tmp; MYSQL_TIME my_time; bool not_used; seconds= (time_t) time((time_t*) 0); localtime_r(&seconds,&tm_tmp); l_time= &tm_tmp; my_time_zone= 3600; /* Comp. for -3600 in my_gmt_sec */ my_time.year= (uint) l_time->tm_year+1900; my_time.month= (uint) l_time->tm_mon+1; my_time.day= (uint) l_time->tm_mday; my_time.hour= (uint) l_time->tm_hour; my_time.minute= (uint) l_time->tm_min; my_time.second= (uint) l_time->tm_sec; my_system_gmt_sec(&my_time, &my_time_zone, ¬_used); /* Init my_time_zone */ } /* Calculate nr of day since year 0 in new date-system (from 1615) */ long calc_daynr(uint year,uint month,uint day) { long delsum; int temp; DBUG_ENTER("calc_daynr"); if (year == 0 && month == 0 && day == 0) DBUG_RETURN(0); /* Skip errors */ if (year < 200) { if ((year=year+1900) < 1900+YY_PART_YEAR) year+=100; } delsum= (long) (365L * year+ 31*(month-1) +day); if (month <= 2) year--; else delsum-= (long) (month*4+23)/10; temp=(int) ((year/100+1)*3)/4; DBUG_PRINT("exit",("year: %d month: %d day: %d -> daynr: %ld", year+(month <= 2),month,day,delsum+year/4-temp)); DBUG_RETURN(delsum+(int) year/4-temp); } /* calc_daynr */ /* Convert time in MYSQL_TIME representation in system time zone to its my_time_t form (number of seconds in UTC since begginning of Unix Epoch). SYNOPSIS my_system_gmt_sec() t - time value to be converted my_timezone - pointer to long where offset of system time zone from UTC will be stored for caching in_dst_time_gap - set to true if time falls into spring time-gap NOTES The idea is to cache the time zone offset from UTC (including daylight saving time) for the next call to make things faster. But currently we just calculate this offset during startup (by calling init_time() function) and use it all the time. Time value provided should be legal time value (e.g. '2003-01-01 25:00:00' is not allowed). RETURN VALUE Time in UTC seconds since Unix Epoch representation. */ my_time_t my_system_gmt_sec(const MYSQL_TIME *t_src, long *my_timezone, bool *in_dst_time_gap) { uint loop; time_t tmp= 0; int shift= 0; MYSQL_TIME tmp_time; MYSQL_TIME *t= &tmp_time; struct tm *l_time,tm_tmp; long diff, current_timezone; /* Use temp variable to avoid trashing input data, which could happen in case of shift required for boundary dates processing. */ memcpy(&tmp_time, t_src, sizeof(MYSQL_TIME)); if (!validate_timestamp_range(t)) return 0; /* Calculate the gmt time based on current time and timezone The -1 on the end is to ensure that if have a date that exists twice (like 2002-10-27 02:00:0 MET), we will find the initial date. By doing -3600 we will have to call localtime_r() several times, but I couldn't come up with a better way to get a repeatable result :( We can't use mktime() as it's buggy on many platforms and not thread safe. Note: this code assumes that our time_t estimation is not too far away from real value (we assume that localtime_r(tmp) will return something within 24 hrs from t) which is probably true for all current time zones. Note2: For the dates, which have time_t representation close to MAX_INT32 (efficient time_t limit for supported platforms), we should do a small trick to avoid overflow. That is, convert the date, which is two days earlier, and then add these days to the final value. The same trick is done for the values close to 0 in time_t representation for platfroms with unsigned time_t (QNX). To be more verbose, here is a sample (extracted from the code below): (calc_daynr(2038, 1, 19) - (long) days_at_timestart)*86400L + 4*3600L would return -2147480896 because of the long type overflow. In result we would get 1901 year in localtime_r(), which is an obvious error. Alike problem raises with the dates close to Epoch. E.g. (calc_daynr(1969, 12, 31) - (long) days_at_timestart)*86400L + 23*3600L will give -3600. On some platforms, (E.g. on QNX) time_t is unsigned and localtime(-3600) wil give us a date around 2106 year. Which is no good. Theoreticaly, there could be problems with the latter conversion: there are at least two timezones, which had time switches near 1 Jan of 1970 (because of political reasons). These are America/Hermosillo and America/Mazatlan time zones. They changed their offset on 1970-01-01 08:00:00 UTC from UTC-8 to UTC-7. For these zones the code below will give incorrect results for dates close to 1970-01-01, in the case OS takes into account these historical switches. Luckily, it seems that we support only one platform with unsigned time_t. It's QNX. And QNX does not support historical timezone data at all. E.g. there are no /usr/share/zoneinfo/ files or any other mean to supply historical information for localtime_r() etc. That is, the problem is not relevant to QNX. We are safe with shifts close to MAX_INT32, as there are no known time switches on Jan 2038 yet :) */ if ((t->year == TIMESTAMP_MAX_YEAR) && (t->month == 1) && (t->day > 4)) { /* Below we will pass (uint) (t->day - shift) to calc_daynr. As we don't want to get an overflow here, we will shift only safe dates. That's why we have (t->day > 4) above. */ t->day-= 2; shift= 2; } #ifdef TIME_T_UNSIGNED else { /* We can get 0 in time_t representaion only on 1969, 31 of Dec or on 1970, 1 of Jan. For both dates we use shift, which is added to t->day in order to step out a bit from the border. This is required for platforms, where time_t is unsigned. As far as I know, among the platforms we support it's only QNX. Note: the order of below if-statements is significant. */ if ((t->year == TIMESTAMP_MIN_YEAR + 1) && (t->month == 1) && (t->day <= 10)) { t->day+= 2; shift= -2; } if ((t->year == TIMESTAMP_MIN_YEAR) && (t->month == 12) && (t->day == 31)) { t->year++; t->month= 1; t->day= 2; shift= -2; } } #endif tmp= (time_t) (((calc_daynr((uint) t->year, (uint) t->month, (uint) t->day) - (long) days_at_timestart)*86400L + (long) t->hour*3600L + (long) (t->minute*60 + t->second)) + (time_t) my_time_zone - 3600); current_timezone= my_time_zone; localtime_r(&tmp,&tm_tmp); l_time=&tm_tmp; for (loop=0; loop < 2 && (t->hour != (uint) l_time->tm_hour || t->minute != (uint) l_time->tm_min || t->second != (uint) l_time->tm_sec); loop++) { /* One check should be enough ? */ /* Get difference in days */ int days= t->day - l_time->tm_mday; if (days < -1) days= 1; /* Month has wrapped */ else if (days > 1) days= -1; diff=(3600L*(long) (days*24+((int) t->hour - (int) l_time->tm_hour)) + (long) (60*((int) t->minute - (int) l_time->tm_min)) + (long) ((int) t->second - (int) l_time->tm_sec)); current_timezone+= diff+3600; /* Compensate for -3600 above */ tmp+= (time_t) diff; localtime_r(&tmp,&tm_tmp); l_time=&tm_tmp; } /* Fix that if we are in the non existing daylight saving time hour we move the start of the next real hour. This code doesn't handle such exotical thing as time-gaps whose length is more than one hour or non-integer (latter can theoretically happen if one of seconds will be removed due leap correction, or because of general time correction like it happened for Africa/Monrovia time zone in year 1972). */ if (loop == 2 && t->hour != (uint) l_time->tm_hour) { int days= t->day - l_time->tm_mday; if (days < -1) days=1; /* Month has wrapped */ else if (days > 1) days= -1; diff=(3600L*(long) (days*24+((int) t->hour - (int) l_time->tm_hour))+ (long) (60*((int) t->minute - (int) l_time->tm_min)) + (long) ((int) t->second - (int) l_time->tm_sec)); if (diff == 3600) tmp+=3600 - t->minute*60 - t->second; /* Move to next hour */ else if (diff == -3600) tmp-=t->minute*60 + t->second; /* Move to previous hour */ *in_dst_time_gap= 1; } *my_timezone= current_timezone; /* shift back, if we were dealing with boundary dates */ tmp+= shift*86400L; /* This is possible for dates, which slightly exceed boundaries. Conversion will pass ok for them, but we don't allow them. First check will pass for platforms with signed time_t. instruction above (tmp+= shift*86400L) could exceed MAX_INT32 (== TIMESTAMP_MAX_VALUE) and overflow will happen. So, tmp < TIMESTAMP_MIN_VALUE will be triggered. On platfroms with unsigned time_t tmp+= shift*86400L might result in a number, larger then TIMESTAMP_MAX_VALUE, so another check will work. */ if ((tmp < TIMESTAMP_MIN_VALUE) || (tmp > TIMESTAMP_MAX_VALUE)) tmp= 0; end: return (my_time_t) tmp; } /* my_system_gmt_sec */ /* Set MYSQL_TIME structure to 0000-00-00 00:00:00.000000 */ void set_zero_time(MYSQL_TIME *tm, enum enum_mysql_timestamp_type time_type) { bzero((void*) tm, sizeof(*tm)); tm->time_type= time_type; } /* Functions to convert time/date/datetime value to a string, using default format. This functions don't check that given TIME structure members are in valid range. If they are not, return value won't reflect any valid date either. Additionally, make_time doesn't take into account time->day member: it's assumed that days have been converted to hours already. RETURN number of characters written to 'to' */ int my_time_to_str(const MYSQL_TIME *l_time, char *to) { uint extra_hours= 0; return my_sprintf(to, (to, "%s%02d:%02d:%02d", (l_time->neg ? "-" : ""), extra_hours+ l_time->hour, l_time->minute, l_time->second)); } int my_date_to_str(const MYSQL_TIME *l_time, char *to) { return my_sprintf(to, (to, "%04d-%02d-%02d", l_time->year, l_time->month, l_time->day)); } int my_datetime_to_str(const MYSQL_TIME *l_time, char *to) { return my_sprintf(to, (to, "%04d-%02d-%02d %02d:%02d:%02d", l_time->year, l_time->month, l_time->day, l_time->hour, l_time->minute, l_time->second)); } /* Convert struct DATE/TIME/DATETIME value to string using built-in MySQL time conversion formats. SYNOPSIS my_TIME_to_string() NOTE The string must have at least MAX_DATE_STRING_REP_LENGTH bytes reserved. */ int my_TIME_to_str(const MYSQL_TIME *l_time, char *to) { switch (l_time->time_type) { case MYSQL_TIMESTAMP_DATETIME: return my_datetime_to_str(l_time, to); case MYSQL_TIMESTAMP_DATE: return my_date_to_str(l_time, to); case MYSQL_TIMESTAMP_TIME: return my_time_to_str(l_time, to); case MYSQL_TIMESTAMP_NONE: case MYSQL_TIMESTAMP_ERROR: to[0]='\0'; return 0; default: DBUG_ASSERT(0); return 0; } }