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Diffstat (limited to 'src/time64.c')
| -rw-r--r-- | src/time64.c | 836 |
1 files changed, 836 insertions, 0 deletions
diff --git a/src/time64.c b/src/time64.c new file mode 100644 index 0000000..8f82e39 --- /dev/null +++ b/src/time64.c @@ -0,0 +1,836 @@ +/* + +Copyright (c) 2007-2010 Michael G Schwern + +This software originally derived from Paul Sheer's pivotal_gmtime_r.c. + +The MIT License: + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. + +*/ + +/* + +Programmers who have available to them 64-bit time values as a 'long +long' type can use localtime64_r() and gmtime64_r() which correctly +converts the time even on 32-bit systems. Whether you have 64-bit time +values will depend on the operating system. + +localtime64_r() is a 64-bit equivalent of localtime_r(). + +gmtime64_r() is a 64-bit equivalent of gmtime_r(). + +*/ + +#include <assert.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <time.h> +#include <errno.h> +#include "time64.h" +#include "time64_limits.h" + + +/* Spec says except for stftime() and the _r() functions, these + all return static memory. Stabbings! */ +static struct TM Static_Return_Date; +static char Static_Return_String[35]; + +static const char days_in_month[2][12] = { + {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, + {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, +}; + +static const short julian_days_by_month[2][12] = { + {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}, + {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}, +}; + +static char wday_name[7][4] = { + "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" +}; + +static char mon_name[12][4] = { + "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" +}; + +static const short length_of_year[2] = { 365, 366 }; + +/* Some numbers relating to the gregorian cycle */ +static const Year years_in_gregorian_cycle = 400; +#define days_in_gregorian_cycle ((365 * 400) + 100 - 4 + 1) +static const Time64_T seconds_in_gregorian_cycle = days_in_gregorian_cycle * 60LL * 60LL * 24LL; + +/* Year range we can trust the time funcitons with */ +#define MAX_SAFE_YEAR 2037 +#define MIN_SAFE_YEAR 1971 + +/* 28 year Julian calendar cycle */ +#define SOLAR_CYCLE_LENGTH 28 + +/* Year cycle from MAX_SAFE_YEAR down. */ +static const short safe_years_high[SOLAR_CYCLE_LENGTH] = { + 2016, 2017, 2018, 2019, + 2020, 2021, 2022, 2023, + 2024, 2025, 2026, 2027, + 2028, 2029, 2030, 2031, + 2032, 2033, 2034, 2035, + 2036, 2037, 2010, 2011, + 2012, 2013, 2014, 2015 +}; + +/* Year cycle from MIN_SAFE_YEAR up */ +static const int safe_years_low[SOLAR_CYCLE_LENGTH] = { + 1996, 1997, 1998, 1971, + 1972, 1973, 1974, 1975, + 1976, 1977, 1978, 1979, + 1980, 1981, 1982, 1983, + 1984, 1985, 1986, 1987, + 1988, 1989, 1990, 1991, + 1992, 1993, 1994, 1995, +}; + +/* This isn't used, but it's handy to look at */ +#if 0 +static const char dow_year_start[SOLAR_CYCLE_LENGTH] = { + 5, 0, 1, 2, /* 0 2016 - 2019 */ + 3, 5, 6, 0, /* 4 */ + 1, 3, 4, 5, /* 8 1996 - 1998, 1971*/ + 6, 1, 2, 3, /* 12 1972 - 1975 */ + 4, 6, 0, 1, /* 16 */ + 2, 4, 5, 6, /* 20 2036, 2037, 2010, 2011 */ + 0, 2, 3, 4 /* 24 2012, 2013, 2014, 2015 */ +}; +#endif + +/* Let's assume people are going to be looking for dates in the future. + Let's provide some cheats so you can skip ahead. + This has a 4x speed boost when near 2008. +*/ +/* Number of days since epoch on Jan 1st, 2008 GMT */ +#define CHEAT_DAYS (1199145600 / 24 / 60 / 60) +#define CHEAT_YEARS 108 + +#define IS_LEAP(n) ((!(((n) + 1900) % 400) || (!(((n) + 1900) % 4) && (((n) + 1900) % 100))) != 0) +#define WRAP(a,b,m) ((a) = ((a) < 0 ) ? ((b)--, (a) + (m)) : (a)) + +#ifdef USE_SYSTEM_LOCALTIME +# define SHOULD_USE_SYSTEM_LOCALTIME(a) ( \ + (a) <= SYSTEM_LOCALTIME_MAX && \ + (a) >= SYSTEM_LOCALTIME_MIN \ +) +#else +# define SHOULD_USE_SYSTEM_LOCALTIME(a) (0) +#endif + +#ifdef USE_SYSTEM_GMTIME +# define SHOULD_USE_SYSTEM_GMTIME(a) ( \ + (a) <= SYSTEM_GMTIME_MAX && \ + (a) >= SYSTEM_GMTIME_MIN \ +) +#else +# define SHOULD_USE_SYSTEM_GMTIME(a) (0) +#endif + +/* Multi varadic macros are a C99 thing, alas */ +#ifdef TIME_64_DEBUG +# define TIME64_TRACE(format) (fprintf(stderr, format)) +# define TIME64_TRACE1(format, var1) (fprintf(stderr, format, var1)) +# define TIME64_TRACE2(format, var1, var2) (fprintf(stderr, format, var1, var2)) +# define TIME64_TRACE3(format, var1, var2, var3) (fprintf(stderr, format, var1, var2, var3)) +#else +# define TIME64_TRACE(format) ((void)0) +# define TIME64_TRACE1(format, var1) ((void)0) +# define TIME64_TRACE2(format, var1, var2) ((void)0) +# define TIME64_TRACE3(format, var1, var2, var3) ((void)0) +#endif + + +static int is_exception_century(Year year) +{ + int is_exception = ((year % 100 == 0) && !(year % 400 == 0)); + TIME64_TRACE1("# is_exception_century: %s\n", is_exception ? "yes" : "no"); + + return(is_exception); +} + + +/* Compare two dates. + The result is like cmp. + Ignores things like gmtoffset and dst +*/ +static int cmp_date( const struct TM* left, const struct tm* right ) { + if( left->tm_year > right->tm_year ) + return 1; + else if( left->tm_year < right->tm_year ) + return -1; + + if( left->tm_mon > right->tm_mon ) + return 1; + else if( left->tm_mon < right->tm_mon ) + return -1; + + if( left->tm_mday > right->tm_mday ) + return 1; + else if( left->tm_mday < right->tm_mday ) + return -1; + + if( left->tm_hour > right->tm_hour ) + return 1; + else if( left->tm_hour < right->tm_hour ) + return -1; + + if( left->tm_min > right->tm_min ) + return 1; + else if( left->tm_min < right->tm_min ) + return -1; + + if( left->tm_sec > right->tm_sec ) + return 1; + else if( left->tm_sec < right->tm_sec ) + return -1; + + return 0; +} + + +/* Check if a date is safely inside a range. + The intention is to check if its a few days inside. +*/ +static int date_in_safe_range( const struct TM* date, const struct tm* min, const struct tm* max ) { + if( cmp_date(date, min) == -1 ) + return 0; + + if( cmp_date(date, max) == 1 ) + return 0; + + return 1; +} + + +/* timegm() is not in the C or POSIX spec, but it is such a useful + extension I would be remiss in leaving it out. Also I need it + for localtime64() +*/ +Time64_T timegm64(const struct TM *date) { + Time64_T days = 0; + Time64_T seconds = 0; + Year year; + Year orig_year = (Year)date->tm_year; + int cycles = 0; + + if( orig_year > 100 ) { + cycles = (orig_year - 100) / 400; + orig_year -= cycles * 400; + days += (Time64_T)cycles * days_in_gregorian_cycle; + } + else if( orig_year < -300 ) { + cycles = (orig_year - 100) / 400; + orig_year -= cycles * 400; + days += (Time64_T)cycles * days_in_gregorian_cycle; + } + TIME64_TRACE3("# timegm/ cycles: %d, days: %lld, orig_year: %lld\n", cycles, days, orig_year); + + if( orig_year > 70 ) { + year = 70; + while( year < orig_year ) { + days += length_of_year[IS_LEAP(year)]; + year++; + } + } + else if ( orig_year < 70 ) { + year = 69; + do { + days -= length_of_year[IS_LEAP(year)]; + year--; + } while( year >= orig_year ); + } + + days += julian_days_by_month[IS_LEAP(orig_year)][date->tm_mon]; + days += date->tm_mday - 1; + + seconds = days * 60 * 60 * 24; + + seconds += date->tm_hour * 60 * 60; + seconds += date->tm_min * 60; + seconds += date->tm_sec; + + return(seconds); +} + + +static int check_tm(struct TM *tm) +{ + /* Don't forget leap seconds */ + assert(tm->tm_sec >= 0); + assert(tm->tm_sec <= 61); + + assert(tm->tm_min >= 0); + assert(tm->tm_min <= 59); + + assert(tm->tm_hour >= 0); + assert(tm->tm_hour <= 23); + + assert(tm->tm_mday >= 1); + assert(tm->tm_mday <= days_in_month[IS_LEAP(tm->tm_year)][tm->tm_mon]); + + assert(tm->tm_mon >= 0); + assert(tm->tm_mon <= 11); + + assert(tm->tm_wday >= 0); + assert(tm->tm_wday <= 6); + + assert(tm->tm_yday >= 0); + assert(tm->tm_yday <= length_of_year[IS_LEAP(tm->tm_year)]); + +#ifdef HAVE_TM_TM_GMTOFF + assert(tm->tm_gmtoff >= -24 * 60 * 60); + assert(tm->tm_gmtoff <= 24 * 60 * 60); +#endif + + return 1; +} + + +/* The exceptional centuries without leap years cause the cycle to + shift by 16 +*/ +static Year cycle_offset(Year year) +{ + const Year start_year = 2000; + Year year_diff = year - start_year; + Year exceptions; + + if( year > start_year ) + year_diff--; + + exceptions = year_diff / 100; + exceptions -= year_diff / 400; + + TIME64_TRACE3("# year: %lld, exceptions: %lld, year_diff: %lld\n", + year, exceptions, year_diff); + + return exceptions * 16; +} + +/* For a given year after 2038, pick the latest possible matching + year in the 28 year calendar cycle. + + A matching year... + 1) Starts on the same day of the week. + 2) Has the same leap year status. + + This is so the calendars match up. + + Also the previous year must match. When doing Jan 1st you might + wind up on Dec 31st the previous year when doing a -UTC time zone. + + Finally, the next year must have the same start day of week. This + is for Dec 31st with a +UTC time zone. + It doesn't need the same leap year status since we only care about + January 1st. +*/ +static int safe_year(const Year year) +{ + int safe_year; + Year year_cycle; + + if( year >= MIN_SAFE_YEAR && year <= MAX_SAFE_YEAR ) { + return (int)year; + } + + year_cycle = year + cycle_offset(year); + + /* safe_years_low is off from safe_years_high by 8 years */ + if( year < MIN_SAFE_YEAR ) + year_cycle -= 8; + + /* Change non-leap xx00 years to an equivalent */ + if( is_exception_century(year) ) + year_cycle += 11; + + /* Also xx01 years, since the previous year will be wrong */ + if( is_exception_century(year - 1) ) + year_cycle += 17; + + year_cycle %= SOLAR_CYCLE_LENGTH; + if( year_cycle < 0 ) + year_cycle = SOLAR_CYCLE_LENGTH + year_cycle; + + assert( year_cycle >= 0 ); + assert( year_cycle < SOLAR_CYCLE_LENGTH ); + if( year < MIN_SAFE_YEAR ) + safe_year = safe_years_low[year_cycle]; + else if( year > MAX_SAFE_YEAR ) + safe_year = safe_years_high[year_cycle]; + else + assert(0); + + TIME64_TRACE3("# year: %lld, year_cycle: %lld, safe_year: %d\n", + year, year_cycle, safe_year); + + assert(safe_year <= MAX_SAFE_YEAR && safe_year >= MIN_SAFE_YEAR); + + return safe_year; +} + + +void copy_tm_to_TM64(const struct tm *src, struct TM *dest) { + if( src == NULL ) { + memset(dest, 0, sizeof(*dest)); + } + else { +# ifdef USE_TM64 + dest->tm_sec = src->tm_sec; + dest->tm_min = src->tm_min; + dest->tm_hour = src->tm_hour; + dest->tm_mday = src->tm_mday; + dest->tm_mon = src->tm_mon; + dest->tm_year = (Year)src->tm_year; + dest->tm_wday = src->tm_wday; + dest->tm_yday = src->tm_yday; + dest->tm_isdst = src->tm_isdst; + +# ifdef HAVE_TM_TM_GMTOFF + dest->tm_gmtoff = src->tm_gmtoff; +# endif + +# ifdef HAVE_TM_TM_ZONE + dest->tm_zone = src->tm_zone; +# endif + +# else + /* They're the same type */ + memcpy(dest, src, sizeof(*dest)); +# endif + } +} + + +void copy_TM64_to_tm(const struct TM *src, struct tm *dest) { + if( src == NULL ) { + memset(dest, 0, sizeof(*dest)); + } + else { +# ifdef USE_TM64 + dest->tm_sec = src->tm_sec; + dest->tm_min = src->tm_min; + dest->tm_hour = src->tm_hour; + dest->tm_mday = src->tm_mday; + dest->tm_mon = src->tm_mon; + dest->tm_year = (int)src->tm_year; + dest->tm_wday = src->tm_wday; + dest->tm_yday = src->tm_yday; + dest->tm_isdst = src->tm_isdst; + +# ifdef HAVE_TM_TM_GMTOFF + dest->tm_gmtoff = src->tm_gmtoff; +# endif + +# ifdef HAVE_TM_TM_ZONE + dest->tm_zone = src->tm_zone; +# endif + +# else + /* They're the same type */ + memcpy(dest, src, sizeof(*dest)); +# endif + } +} + + +#ifndef HAVE_LOCALTIME_R +/* Simulate localtime_r() to the best of our ability */ +static struct tm * fake_localtime_r(const time_t *time, struct tm *result) { + const struct tm *static_result = localtime(time); + + assert(result != NULL); + + if( static_result == NULL ) { + memset(result, 0, sizeof(*result)); + return NULL; + } + else { + memcpy(result, static_result, sizeof(*result)); + return result; + } +} +#endif + + +#ifndef HAVE_GMTIME_R +/* Simulate gmtime_r() to the best of our ability */ +static struct tm * fake_gmtime_r(const time_t *time, struct tm *result) { + const struct tm *static_result = gmtime(time); + + assert(result != NULL); + + if( static_result == NULL ) { + memset(result, 0, sizeof(*result)); + return NULL; + } + else { + memcpy(result, static_result, sizeof(*result)); + return result; + } +} +#endif + + +static Time64_T seconds_between_years(Year left_year, Year right_year) { + int increment = (left_year > right_year) ? 1 : -1; + Time64_T seconds = 0; + int cycles; + + if( left_year > 2400 ) { + cycles = (left_year - 2400) / 400; + left_year -= cycles * 400; + seconds += cycles * seconds_in_gregorian_cycle; + } + else if( left_year < 1600 ) { + cycles = (left_year - 1600) / 400; + left_year += cycles * 400; + seconds += cycles * seconds_in_gregorian_cycle; + } + + while( left_year != right_year ) { + seconds += length_of_year[IS_LEAP(right_year - 1900)] * 60 * 60 * 24; + right_year += increment; + } + + return seconds * increment; +} + + +Time64_T mktime64(struct TM *input_date) { + struct tm safe_date; + struct TM date; + Time64_T time; + Year year = input_date->tm_year + 1900; + + if( date_in_safe_range(input_date, &SYSTEM_MKTIME_MIN, &SYSTEM_MKTIME_MAX) ) + { + copy_TM64_to_tm(input_date, &safe_date); + time = (Time64_T)mktime(&safe_date); + + /* Correct the possibly out of bound input date */ + copy_tm_to_TM64(&safe_date, input_date); + return time; + } + + /* Have to make the year safe in date else it won't fit in safe_date */ + date = *input_date; + date.tm_year = safe_year(year) - 1900; + copy_TM64_to_tm(&date, &safe_date); + + time = (Time64_T)mktime(&safe_date); + + /* Correct the user's possibly out of bound input date */ + copy_tm_to_TM64(&safe_date, input_date); + + time += seconds_between_years(year, (Year)(safe_date.tm_year + 1900)); + + return time; +} + + +/* Because I think mktime() is a crappy name */ +Time64_T timelocal64(struct TM *date) { + return mktime64(date); +} + + +struct TM *gmtime64_r (const Time64_T *in_time, struct TM *p) +{ + int v_tm_sec, v_tm_min, v_tm_hour, v_tm_mon, v_tm_wday; + Time64_T v_tm_tday; + int leap; + Time64_T m; + Time64_T time = *in_time; + Year year = 70; + int cycles = 0; + + assert(p != NULL); + + /* Use the system gmtime() if time_t is small enough */ + if( SHOULD_USE_SYSTEM_GMTIME(*in_time) ) { + time_t safe_time = (time_t)*in_time; + struct tm safe_date; + GMTIME_R(&safe_time, &safe_date); + + copy_tm_to_TM64(&safe_date, p); + assert(check_tm(p)); + + return p; + } + +#ifdef HAVE_TM_TM_GMTOFF + p->tm_gmtoff = 0; +#endif + p->tm_isdst = 0; + +#ifdef HAVE_TM_TM_ZONE + p->tm_zone = (char*)"UTC"; +#endif + + v_tm_sec = (int)(time % 60); + time /= 60; + v_tm_min = (int)(time % 60); + time /= 60; + v_tm_hour = (int)(time % 24); + time /= 24; + v_tm_tday = time; + + WRAP (v_tm_sec, v_tm_min, 60); + WRAP (v_tm_min, v_tm_hour, 60); + WRAP (v_tm_hour, v_tm_tday, 24); + + v_tm_wday = (int)((v_tm_tday + 4) % 7); + if (v_tm_wday < 0) + v_tm_wday += 7; + m = v_tm_tday; + + if (m >= CHEAT_DAYS) { + year = CHEAT_YEARS; + m -= CHEAT_DAYS; + } + + if (m >= 0) { + /* Gregorian cycles, this is huge optimization for distant times */ + cycles = (int)(m / (Time64_T) days_in_gregorian_cycle); + if( cycles ) { + m -= (cycles * (Time64_T) days_in_gregorian_cycle); + year += (cycles * years_in_gregorian_cycle); + } + + /* Years */ + leap = IS_LEAP (year); + while (m >= (Time64_T) length_of_year[leap]) { + m -= (Time64_T) length_of_year[leap]; + year++; + leap = IS_LEAP (year); + } + + /* Months */ + v_tm_mon = 0; + while (m >= (Time64_T) days_in_month[leap][v_tm_mon]) { + m -= (Time64_T) days_in_month[leap][v_tm_mon]; + v_tm_mon++; + } + } else { + year--; + + /* Gregorian cycles */ + cycles = (int)((m / (Time64_T) days_in_gregorian_cycle) + 1); + if( cycles ) { + m -= (cycles * (Time64_T) days_in_gregorian_cycle); + year += (cycles * years_in_gregorian_cycle); + } + + /* Years */ + leap = IS_LEAP (year); + while (m < (Time64_T) -length_of_year[leap]) { + m += (Time64_T) length_of_year[leap]; + year--; + leap = IS_LEAP (year); + } + + /* Months */ + v_tm_mon = 11; + while (m < (Time64_T) -days_in_month[leap][v_tm_mon]) { + m += (Time64_T) days_in_month[leap][v_tm_mon]; + v_tm_mon--; + } + m += (Time64_T) days_in_month[leap][v_tm_mon]; + } + + p->tm_year = year; + if( p->tm_year != year ) { +#ifdef EOVERFLOW + errno = EOVERFLOW; +#endif + return NULL; + } + + /* At this point m is less than a year so casting to an int is safe */ + p->tm_mday = (int) m + 1; + p->tm_yday = julian_days_by_month[leap][v_tm_mon] + (int)m; + p->tm_sec = v_tm_sec; + p->tm_min = v_tm_min; + p->tm_hour = v_tm_hour; + p->tm_mon = v_tm_mon; + p->tm_wday = v_tm_wday; + + assert(check_tm(p)); + + return p; +} + + +struct TM *localtime64_r (const Time64_T *time, struct TM *local_tm) +{ + time_t safe_time; + struct tm safe_date; + struct TM gm_tm; + Year orig_year; + int month_diff; + + assert(local_tm != NULL); + + /* Use the system localtime() if time_t is small enough */ + if( SHOULD_USE_SYSTEM_LOCALTIME(*time) ) { + safe_time = (time_t)*time; + + TIME64_TRACE1("Using system localtime for %lld\n", *time); + + LOCALTIME_R(&safe_time, &safe_date); + + copy_tm_to_TM64(&safe_date, local_tm); + assert(check_tm(local_tm)); + + return local_tm; + } + + if( gmtime64_r(time, &gm_tm) == NULL ) { + TIME64_TRACE1("gmtime64_r returned null for %lld\n", *time); + return NULL; + } + + orig_year = gm_tm.tm_year; + + if (gm_tm.tm_year > (2037 - 1900) || + gm_tm.tm_year < (1970 - 1900) + ) + { + TIME64_TRACE1("Mapping tm_year %lld to safe_year\n", (Year)gm_tm.tm_year); + gm_tm.tm_year = safe_year((Year)(gm_tm.tm_year + 1900)) - 1900; + } + + safe_time = (time_t)timegm64(&gm_tm); + if( LOCALTIME_R(&safe_time, &safe_date) == NULL ) { + TIME64_TRACE1("localtime_r(%d) returned NULL\n", (int)safe_time); + return NULL; + } + + copy_tm_to_TM64(&safe_date, local_tm); + + local_tm->tm_year = orig_year; + if( local_tm->tm_year != orig_year ) { + TIME64_TRACE2("tm_year overflow: tm_year %lld, orig_year %lld\n", + (Year)local_tm->tm_year, (Year)orig_year); + +#ifdef EOVERFLOW + errno = EOVERFLOW; +#endif + return NULL; + } + + + month_diff = local_tm->tm_mon - gm_tm.tm_mon; + + /* When localtime is Dec 31st previous year and + gmtime is Jan 1st next year. + */ + if( month_diff == 11 ) { + local_tm->tm_year--; + } + + /* When localtime is Jan 1st, next year and + gmtime is Dec 31st, previous year. + */ + if( month_diff == -11 ) { + local_tm->tm_year++; + } + + /* GMT is Jan 1st, xx01 year, but localtime is still Dec 31st + in a non-leap xx00. There is one point in the cycle + we can't account for which the safe xx00 year is a leap + year. So we need to correct for Dec 31st comming out as + the 366th day of the year. + */ + if( !IS_LEAP(local_tm->tm_year) && local_tm->tm_yday == 365 ) + local_tm->tm_yday--; + + assert(check_tm(local_tm)); + + return local_tm; +} + + +static int valid_tm_wday( const struct TM* date ) { + if( 0 <= date->tm_wday && date->tm_wday <= 6 ) + return 1; + else + return 0; +} + +static int valid_tm_mon( const struct TM* date ) { + if( 0 <= date->tm_mon && date->tm_mon <= 11 ) + return 1; + else + return 0; +} + + +char *asctime64_r( const struct TM* date, char *result ) { + /* I figure everything else can be displayed, even hour 25, but if + these are out of range we walk off the name arrays */ + if( !valid_tm_wday(date) || !valid_tm_mon(date) ) + return NULL; + + sprintf(result, TM64_ASCTIME_FORMAT, + wday_name[date->tm_wday], + mon_name[date->tm_mon], + date->tm_mday, date->tm_hour, + date->tm_min, date->tm_sec, + 1900 + date->tm_year); + + return result; +} + + +char *ctime64_r( const Time64_T* time, char* result ) { + struct TM date; + + localtime64_r( time, &date ); + return asctime64_r( &date, result ); +} + + +/* Non-thread safe versions of the above */ +struct TM *localtime64(const Time64_T *time) { + tzset(); + return localtime64_r(time, &Static_Return_Date); +} + +struct TM *gmtime64(const Time64_T *time) { + return gmtime64_r(time, &Static_Return_Date); +} + +char *asctime64( const struct TM* date ) { + return asctime64_r( date, Static_Return_String ); +} + +char *ctime64( const Time64_T* time ) { + tzset(); + return asctime64(localtime64(time)); +} |