diff options
Diffstat (limited to 'include/ntp_calendar.h')
| -rw-r--r-- | include/ntp_calendar.h | 372 |
1 files changed, 338 insertions, 34 deletions
diff --git a/include/ntp_calendar.h b/include/ntp_calendar.h index fbdb27c7ab4f..3ee1ff79c806 100644 --- a/include/ntp_calendar.h +++ b/include/ntp_calendar.h @@ -4,20 +4,62 @@ #ifndef NTP_CALENDAR_H #define NTP_CALENDAR_H +#include <time.h> + #include "ntp_types.h" +/* gregorian calendar date */ struct calendar { - u_short year; /* year (A.D.) */ - u_short yearday; /* day of year, 1 = January 1 */ - u_char month; /* month, 1 = January */ - u_char monthday; /* day of month */ - u_char hour; /* hour of day, midnight = 0 */ - u_char minute; /* minute of hour */ - u_char second; /* second of minute */ + uint16_t year; /* year (A.D.) */ + uint16_t yearday; /* day of year, 1 = January 1 */ + uint8_t month; /* month, 1 = January */ + uint8_t monthday; /* day of month */ + uint8_t hour; /* hour of day, midnight = 0 */ + uint8_t minute; /* minute of hour */ + uint8_t second; /* second of minute */ + uint8_t weekday; /* 0..7, 0=Sunday */ +}; + +/* ISO week calendar date */ +struct isodate { + uint16_t year; /* year (A.D.) */ + uint8_t week; /* 1..53, week in year */ + uint8_t weekday; /* 1..7, 1=Monday */ + uint8_t hour; /* hour of day, midnight = 0 */ + uint8_t minute; /* minute of hour */ + uint8_t second; /* second of minute */ }; +/* general split representation */ +typedef struct { + int32_t hi; + int32_t lo; +} ntpcal_split; + +typedef time_t (*systime_func_ptr)(time_t *); + +/* + * set the function for getting the system time. This is mostly used for + * unit testing to provide a fixed / shifted time stamp. Setting the + * value to NULL restores the original function, that is, 'time()', + * which is also the automatic default. + */ +extern systime_func_ptr ntpcal_set_timefunc(systime_func_ptr); + /* - * Days in each month. 30 days hath September... + * days-of-week + */ +#define CAL_SUNDAY 0 +#define CAL_MONDAY 1 +#define CAL_TUESDAY 2 +#define CAL_WEDNESDAY 3 +#define CAL_THURSDAY 4 +#define CAL_FRIDAY 5 +#define CAL_SATURDAY 6 +#define CAL_SUNDAY7 7 /* also sunday */ + +/* + * Days in each month. 30 days hath September... */ #define JAN 31 #define FEB 28 @@ -34,7 +76,7 @@ struct calendar { #define DEC 31 /* - * We deal in a 4 year cycle starting at March 1, 1900. We assume + * We deal in a 4 year cycle starting at March 1, 1900. We assume * we will only want to deal with dates since then, and not to exceed * the rollover day in 2036. */ @@ -43,17 +85,14 @@ struct calendar { #define HRSPERDAY (24) /* hours per day */ #define DAYSPERYEAR (365) /* days per year */ -#define SECSPERDAY (SECSPERMIN*MINSPERHR*HRSPERDAY) +#define SECSPERHR (SECSPERMIN * MINSPERHR) +#define SECSPERDAY (SECSPERHR * HRSPERDAY) #define SECSPERYEAR (365 * SECSPERDAY) /* regular year */ #define SECSPERLEAPYEAR (366 * SECSPERDAY) /* leap year */ - -#define MAR1900 ((JAN+FEB) * SECSPERDAY) /* no leap year in 1900 */ -#define DAYSPERCYCLE (365+365+365+366) /* 3 normal years plus leap */ -#define SECSPERCYCLE (DAYSPERCYCLE*SECSPERDAY) -#define YEARSPERCYCLE 4 +#define SECSPERAVGYEAR 31556952 /* mean year length over 400yrs */ /* - * Gross hacks. I have illicit knowlege that there won't be overflows + * Gross hacks. I have illicit knowlege that there won't be overflows * here, the compiler often can't tell this. */ #define TIMES60(val) ((((val)<<4) - (val))<<2) /* *(16 - 1) * 4 */ @@ -63,23 +102,270 @@ struct calendar { + ((val)<<7) + ((val)<<5) \ + ((val)<<4) + ((val)<<2) + (val)) /* *big* hack */ + +extern const char * const months[12]; +extern const char * const daynames[7]; + +extern void caljulian (uint32_t, struct calendar *); +extern uint32_t caltontp (const struct calendar *); + /* - * Another big hack. Cycle 22 started on March 1, 1988. This is - * STARTCYCLE22 seconds after the start of cycle 0. + * Convert between 'time_t' and 'vint64' */ -#define CYCLE22 (22) -#define STARTCYCLE22 (u_long)(0xa586b500) /* 2777068800 */ -#define MAR1988 (u_long)(STARTCYCLE22 + (u_long)MAR1900) +extern vint64 time_to_vint64(const time_t *); +extern time_t vint64_to_time(const vint64 *); /* - * The length of January + February in leap and non-leap years. + * Get the build date & time. ATTENTION: The time zone is not specified! + * This depends entirely on the C compilers' capabilities to properly + * expand the '__TIME__' and '__DATE__' macros, as required by the C + * standard. */ -#define JANFEBNOLEAP ((JAN+FEB) * SECSPERDAY) -#define JANFEBLEAP ((JAN+FEBLEAP) * SECSPERDAY) +extern int +ntpcal_get_build_date(struct calendar * /* jd */); +/* + * Convert a timestamp in NTP scale to a time_t value in the UN*X + * scale with proper epoch unfolding around a given pivot or the + * current system time. + */ +extern vint64 +ntpcal_ntp_to_time(uint32_t /* ntp */, const time_t * /* pivot */); + +/* + * Convert a timestamp in NTP scale to a 64bit seconds value in the NTP + * scale with proper epoch unfolding around a given pivot or the current + * system time. + * Note: The pivot must be given in UN*X time scale! + */ +extern vint64 +ntpcal_ntp_to_ntp(uint32_t /* ntp */, const time_t * /* pivot */); + +/* + * Split a time stamp in seconds into elapsed days and elapsed seconds + * since midnight. + */ +extern ntpcal_split +ntpcal_daysplit(const vint64 *); -extern void caljulian (u_long, struct calendar *); -extern u_long caltontp (const struct calendar *); +/* + * Merge a number of days and a number of seconds into seconds, + * expressed in 64 bits to avoid overflow. + */ +extern vint64 +ntpcal_dayjoin(int32_t /* days */, int32_t /* seconds */); + +/* + * Convert elapsed years in Era into elapsed days in Era. + */ +extern int32_t +ntpcal_days_in_years(int32_t /* years */); + +/* + * Convert a number of elapsed month in a year into elapsed days + * in year. + * + * The month will be normalized, and 'res.hi' will contain the + * excessive years that must be considered when converting the years, + * while 'res.lo' will contain the days since start of the + * year. (Expect the resulting days to be negative, with a positive + * excess! But then, we need no leap year flag, either...) + */ +extern ntpcal_split +ntpcal_days_in_months(int32_t /* months */); + +/* + * Convert ELAPSED years/months/days of gregorian calendar to elapsed + * days in Gregorian epoch. No range checks done here! + */ +extern int32_t +ntpcal_edate_to_eradays(int32_t /* years */, int32_t /* months */, int32_t /* mdays */); + +/* + * Convert a time spec to seconds. No range checks done here! + */ +extern int32_t +ntpcal_etime_to_seconds(int32_t /* hours */, int32_t /* minutes */, int32_t /* seconds */); + +/* + * Convert ELAPSED years/months/days of gregorian calendar to elapsed + * days in year. + * + * Note: This will give the true difference to the start of the given year, + * even if months & days are off-scale. + */ +extern int32_t +ntpcal_edate_to_yeardays(int32_t /* years */, int32_t /* months */, int32_t /* mdays */); + +/* + * Convert the date part of a 'struct tm' (that is, year, month, + * day-of-month) into the RataDie of that day. + */ +extern int32_t +ntpcal_tm_to_rd(const struct tm * /* utm */); + +/* + * Convert the date part of a 'struct calendar' (that is, year, month, + * day-of-month) into the RataDie of that day. + */ +extern int32_t +ntpcal_date_to_rd(const struct calendar * /* jt */); + +/* + * Given the number of elapsed days in the calendar era, split this + * number into the number of elapsed years in 'res.quot' and the + * number of elapsed days of that year in 'res.rem'. + * + * if 'isleapyear' is not NULL, it will receive an integer that is 0 + * for regular years and a non-zero value for leap years. + */ +extern ntpcal_split +ntpcal_split_eradays(int32_t /* days */, int/*BOOL*/ * /* isleapyear */); + +/* + * Given a number of elapsed days in a year and a leap year indicator, + * split the number of elapsed days into the number of elapsed months + * in 'res.quot' and the number of elapsed days of that month in + * 'res.rem'. + */ +extern ntpcal_split +ntpcal_split_yeardays(int32_t /* eyd */, int/*BOOL*/ /* isleapyear */); + +/* + * Convert a RataDie number into the date part of a 'struct + * calendar'. Return 0 if the year is regular year, !0 if the year is + * a leap year. + */ +extern int/*BOOL*/ +ntpcal_rd_to_date(struct calendar * /* jt */, int32_t /* rd */); + +/* + * Convert a RataDie number into the date part of a 'struct + * tm'. Return 0 if the year is regular year, !0 if the year is a leap + * year. + */ +extern int/*BOOL*/ +ntpcal_rd_to_tm(struct tm * /* utm */, int32_t /* rd */); + +/* + * Take a value of seconds since midnight and split it into hhmmss in + * a 'struct calendar'. Return excessive days. + */ +extern int32_t +ntpcal_daysec_to_date(struct calendar * /* jt */, int32_t /* secs */); + +/* + * Take the time part of a 'struct calendar' and return the seconds + * since midnight. + */ +extern int32_t +ntpcal_date_to_daysec(const struct calendar *); + +/* + * Take a value of seconds since midnight and split it into hhmmss in + * a 'struct tm'. Return excessive days. + */ +extern int32_t +ntpcal_daysec_to_tm(struct tm * /* utm */, int32_t /* secs */); + +extern int32_t +ntpcal_tm_to_daysec(const struct tm * /* utm */); + +/* + * convert a year number to rata die of year start + */ +extern int32_t +ntpcal_year_to_ystart(int32_t /* year */); + +/* + * For a given RataDie, get the RataDie of the associated year start, + * that is, the RataDie of the last January,1st on or before that day. + */ +extern int32_t +ntpcal_rd_to_ystart(int32_t /* rd */); + +/* + * convert a RataDie to the RataDie of start of the calendar month. + */ +extern int32_t +ntpcal_rd_to_mstart(int32_t /* year */); + + +extern int +ntpcal_daysplit_to_date(struct calendar * /* jt */, + const ntpcal_split * /* ds */, int32_t /* dof */); + +extern int +ntpcal_daysplit_to_tm(struct tm * /* utm */, const ntpcal_split * /* ds */, + int32_t /* dof */); + +extern int +ntpcal_time_to_date(struct calendar * /* jd */, const vint64 * /* ts */); + +extern int32_t +ntpcal_periodic_extend(int32_t /* pivot */, int32_t /* value */, + int32_t /* cycle */); + +extern int +ntpcal_ntp64_to_date(struct calendar * /* jd */, const vint64 * /* ntp */); + +extern int +ntpcal_ntp_to_date(struct calendar * /* jd */, uint32_t /* ntp */, + const time_t * /* pivot */); + +extern vint64 +ntpcal_date_to_ntp64(const struct calendar * /* jd */); + +extern uint32_t +ntpcal_date_to_ntp(const struct calendar * /* jd */); + +extern time_t +ntpcal_date_to_time(const struct calendar * /* jd */); + +/* + * ISO week-calendar conversions + */ +extern int32_t +isocal_weeks_in_years(int32_t /* years */); + +extern ntpcal_split +isocal_split_eraweeks(int32_t /* weeks */); + +extern int +isocal_ntp64_to_date(struct isodate * /* id */, const vint64 * /* ntp */); + +extern int +isocal_ntp_to_date(struct isodate * /* id */, uint32_t /* ntp */, + const time_t * /* pivot */); + +extern vint64 +isocal_date_to_ntp64(const struct isodate * /* id */); + +extern uint32_t +isocal_date_to_ntp(const struct isodate * /* id */); + + +/* + * day-of-week calculations + * + * Given a RataDie and a day-of-week, calculate a RDN that is reater-than, + * greater-or equal, closest, less-or-equal or less-than the given RDN + * and denotes the given day-of-week + */ +extern int32_t +ntpcal_weekday_gt(int32_t /* rdn */, int32_t /* dow */); + +extern int32_t +ntpcal_weekday_ge(int32_t /* rdn */, int32_t /* dow */); + +extern int32_t +ntpcal_weekday_close(int32_t /* rdn */, int32_t /* dow */); + +extern int32_t +ntpcal_weekday_le(int32_t /* rdn */, int32_t /* dow */); + +extern int32_t +ntpcal_weekday_lt(int32_t /* rdn */, int32_t /* dow */); /* * Additional support stuff for Ed Rheingold's calendrical calculations @@ -90,22 +376,40 @@ extern u_long caltontp (const struct calendar *); * (This is the beginning of the Christian Era, or BCE.) */ #define DAY_NTP_STARTS 693596 + +/* + * Start day of the UNIX epoch. This is the Rata Die of 1970-01-01. + */ +#define DAY_UNIX_STARTS 719163 + +/* + * Difference between UN*X and NTP epoch (25567). + */ +#define NTP_TO_UNIX_DAYS (DAY_UNIX_STARTS - DAY_NTP_STARTS) + +/* + * Days in a normal 4 year leap year calendar cycle (1461). + */ +#define GREGORIAN_NORMAL_LEAP_CYCLE_DAYS (3 * 365 + 366) + /* - * The Gregorian calendar is based on a 400 year cycle. This is the number - * of days in each cycle. + * Days in a normal 100 year leap year calendar (36524). We lose a + * leap day in years evenly divisible by 100 but not by 400. */ -#define GREGORIAN_CYCLE_DAYS 146097 +#define GREGORIAN_NORMAL_CENTURY_DAYS \ + (25 * GREGORIAN_NORMAL_LEAP_CYCLE_DAYS - 1) /* - * Days in a normal 100 year leap year calendar. We lose a leap year day - * in years evenly divisible by 100 but not by 400. + * The Gregorian calendar is based on a 400 year cycle. This is the + * number of days in each cycle (146097). We gain a leap day in years + * divisible by 400 relative to the "normal" century. */ -#define GREGORIAN_NORMAL_CENTURY_DAYS 36524 +#define GREGORIAN_CYCLE_DAYS (4 * GREGORIAN_NORMAL_CENTURY_DAYS + 1) /* - * Days in a normal 4 year leap year calendar cycle. + * Number of weeks in 400 years (20871). */ -#define GREGORIAN_NORMAL_LEAP_CYCLE_DAYS 1461 +#define GREGORIAN_CYCLE_WEEKS (GREGORIAN_CYCLE_DAYS / 7) #define is_leapyear(y) (!((y) % 4) && !(!((y) % 100) && (y) % 400)) |