amxc_timestamp.c File Reference

#include <unistd.h>
#include <sys/time.h>
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <amxc/amxc_timestamp.h>
#include <amxc/amxc_macros.h>

Go to the source code of this file.

Macros
#define	_GNU_SOURCE
#define	EPOCH   INT64_C(62135683200) /* 1970-01-01T00:00:00 */
#define	MIN_SEC   INT64_C(-62135596800) /* 0001-01-01T00:00:00 */
#define	MAX_SEC   INT64_C(253402300799) /* 9999-12-31T23:59:59 */
#define	RDN_OFFSET   INT64_C(62135683200) /* 1970-01-01T00:00:00 */

Functions
static int	leap_year (uint16_t y)
static unsigned char	month_days (uint16_t y, uint16_t m)
static int	parse_2d (const unsigned char *const p, size_t i, uint16_t *vp)
static int	parse_4d (const unsigned char *const p, size_t i, uint16_t *vp)
static void	rdn_to_ymd (uint32_t rdn, uint16_t *yp, uint16_t *mp, uint16_t *dp)
static size_t	timestamp_format_internal (char *dst, size_t len, const amxc_ts_t *tsp, const int precision)
static void	rdn_to_struct_tm (uint32_t rdn, struct tm *tmp)
static int	timestamp_to_tm (const amxc_ts_t *tsp, struct tm *tmp, const bool local)
int	amxc_ts_now (amxc_ts_t *tsp)
	Takes current time as unix epoch time. More...
static int	amxc_ts_parse_date (const unsigned char *cur, uint16_t *year, uint16_t *month, uint16_t *day)
static int	amxc_ts_parse_time (const unsigned char *cur, uint16_t *hour, uint16_t *min, uint16_t *sec)
static int	amxc_ts_parse_offset (const unsigned char *cur, const unsigned char *end, int16_t *offset)
int	amxc_ts_parse (amxc_ts_t *tsp, const char *str, size_t len)
	Transforms the given string in to unix epoch time. More...
size_t	amxc_ts_format (const amxc_ts_t *tsp, char *dst, size_t len)
	Transforms unix epoch time to a string. More...
size_t	amxc_ts_format_precision (const amxc_ts_t *tsp, char *dst, size_t len, int precision)
	Transforms unix epoch time to a string. More...
int	amxc_ts_compare (const amxc_ts_t *tsp1, const amxc_ts_t *tsp2)
	Checks if tsp1 comes after tsp2. More...
bool	amxc_ts_is_valid (const amxc_ts_t *tsp)
	Checks if a timestamp is valid. More...
int	amxc_ts_to_tm_utc (const amxc_ts_t *tsp, struct tm *tmp)
	Converts timestamp in unix epoch time to a struct tm type in UTC time. More...
int	amxc_ts_to_tm_local (const amxc_ts_t *tsp, struct tm *tmp)
	Converts timestamp in unix epoch time to a struct tm type in local time. More...
int	amxc_ts_to_local (amxc_ts_t *tsp)
	Adds the local time offset to the timestamp structure. More...
int	amxc_ts_from_tm (amxc_ts_t *const tsp, struct tm *tmp)
	Converts a broken down time in a struct tm to a timestamp structure. More...

Variables
static const uint32_t	Pow10 [10]
static const uint16_t	DayOffset [13]

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

Definition at line 82 of file amxc_timestamp.c.

EPOCH

#define EPOCH   INT64_C(62135683200) /* 1970-01-01T00:00:00 */

Definition at line 95 of file amxc_timestamp.c.

MAX_SEC

#define MAX_SEC   INT64_C(253402300799) /* 9999-12-31T23:59:59 */

Definition at line 97 of file amxc_timestamp.c.

MIN_SEC

#define MIN_SEC   INT64_C(-62135596800) /* 0001-01-01T00:00:00 */

Definition at line 96 of file amxc_timestamp.c.

RDN_OFFSET

#define RDN_OFFSET   INT64_C(62135683200) /* 1970-01-01T00:00:00 */

Definition at line 98 of file amxc_timestamp.c.

Function Documentation

amxc_ts_parse_date()

static int amxc_ts_parse_date ( const unsigned char *  cur, uint16_t *  year, uint16_t *  month, uint16_t *  day  )

static

Definition at line 319 of file amxc_timestamp.c.

                                             {
    int retval = 1;
    when_true(parse_4d(cur, 0, year) || *year < 1, exit);
    when_true(parse_2d(cur, 5, month) || *month < 1 || *month > 12, exit);
    when_true(parse_2d(cur, 8, day) || *day < 1 || *day > 31, exit);
 
    retval = 0;
exit:
    return retval;
}

amxc_ts_parse_offset()

static int amxc_ts_parse_offset ( const unsigned char *  cur, const unsigned char *  end, int16_t *  offset  )

static

Definition at line 347 of file amxc_timestamp.c.

                                                 {
    int retval = -1;
    uint16_t hour;
    uint16_t min;
    unsigned char ch = *cur;
    when_true(cur + 6 < end || !(ch == '+' || ch == '-') || cur[3] != ':', exit);
 
    when_true(parse_2d(cur + 1, 0, &hour) || hour > 23 ||
              parse_2d(cur + 1, 3, &min) || min > 59, exit);
 
    *offset = hour * 60 + min;
    if(ch == '-') {
        *offset *= -1;
    }
 
    retval = 0;
exit:
    return retval;
}

amxc_ts_parse_time()

static int amxc_ts_parse_time ( const unsigned char *  cur, uint16_t *  hour, uint16_t *  min, uint16_t *  sec  )

static

Definition at line 333 of file amxc_timestamp.c.

                                             {
    int retval = 1;
    when_true(parse_2d(cur, 11, hour) || *hour > 23, exit);
    when_true(parse_2d(cur, 14, min) || *min > 59, exit);
    when_true(parse_2d(cur, 17, sec) || *sec > 59, exit);
 
    retval = 0;
exit:
    return retval;
}

leap_year()

static int leap_year ( uint16_t  y )

static

Definition at line 108 of file amxc_timestamp.c.

                                 {
    return ((y & 3) == 0 && (y % 100 != 0 || y % 400 == 0));
}

month_days()

static unsigned char month_days ( uint16_t  y, uint16_t  m  )

static

Definition at line 112 of file amxc_timestamp.c.

                                                        {
    static const unsigned char days[2][13] = {
        {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
        {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
    };
    return days[m == 2 && leap_year(y)][m];
}

parse_2d()

static int parse_2d ( const unsigned char *const  p, size_t  i, uint16_t *  vp  )

static

Definition at line 120 of file amxc_timestamp.c.

                                                                          {
    unsigned char d0, d1;
    if(((d0 = p[i + 0] - '0') > 9) ||
       ((d1 = p[i + 1] - '0') > 9)) {
        return 1;
    }
    *vp = d0 * 10 + d1;
    return 0;
}

parse_4d()

static int parse_4d ( const unsigned char *const  p, size_t  i, uint16_t *  vp  )

static

Definition at line 130 of file amxc_timestamp.c.

                                                                          {
    unsigned char d0, d1, d2, d3;
    if(((d0 = p[i + 0] - '0') > 9) ||
       ((d1 = p[i + 1] - '0') > 9) ||
       ((d2 = p[i + 2] - '0') > 9) ||
       ((d3 = p[i + 3] - '0') > 9)) {
        return 1;
    }
    *vp = d0 * 1000 + d1 * 100 + d2 * 10 + d3;
    return 0;
}

rdn_to_struct_tm()

static void rdn_to_struct_tm ( uint32_t  rdn, struct tm *  tmp  )

static

Definition at line 248 of file amxc_timestamp.c.

                                                           {
    uint32_t Z, H, A, B;
    uint16_t C, y, m, d;
 
    Z = rdn + 306;
    H = 100 * Z - 25;
    A = H / 3652425;
    B = A - (A >> 2);
    y = (100 * B + H) / 36525;
    C = B + Z - (1461 * y >> 2);
    m = (535 * C + 48950) >> 14;
    if(m > 12) {
        d = C - 306, y++, m -= 12;
    } else {
        d = C + 59 + ((y & 3) == 0 && (y % 100 != 0 || y % 400 == 0));
    }
 
    tmp->tm_mday = C - DayOffset[m];    /* Day of month [1,31]           */
    tmp->tm_mon = m - 1;                /* Month of year [0,11]          */
    tmp->tm_year = y - 1900;            /* Years since 1900              */
    tmp->tm_wday = rdn % 7;             /* Day of week [0,6] (Sunday =0) */
    tmp->tm_yday = d - 1;               /* Day of year [0,365]           */
}

rdn_to_ymd()

static void rdn_to_ymd ( uint32_t  rdn, uint16_t *  yp, uint16_t *  mp, uint16_t *  dp  )

static

Definition at line 143 of file amxc_timestamp.c.

                                                                               {
    uint32_t Z, H, A, B;
    uint16_t y, m, d;
 
    Z = rdn + 306;
    H = 100 * Z - 25;
    A = H / 3652425;
    B = A - (A >> 2);
    y = (100 * B + H) / 36525;
    d = B + Z - (1461 * y >> 2);
    m = (535 * d + 48950) >> 14;
    if(m > 12) {
        y++, m -= 12;
    }
 
    *yp = y;
    *mp = m;
    *dp = d - DayOffset[m];
}

timestamp_format_internal()

static size_t timestamp_format_internal ( char *  dst, size_t  len, const amxc_ts_t *  tsp, const int  precision  )

static

Definition at line 163 of file amxc_timestamp.c.

                                                             {
    unsigned char* p;
    uint64_t sec;
    uint32_t rdn, v;
    uint16_t y, m, d;
    size_t dlen;
 
    dlen = sizeof("YYYY-MM-DDThh:mm:ssZ") - 1;
    if(tsp->offset) {
        dlen += 5; /* hh:mm */
    }
    if(precision) {
        dlen += 1 + precision;
    }
    if(dlen >= len) {
        return 0;
    }
    sec = tsp->sec + tsp->offset * 60 + EPOCH;
    rdn = sec / 86400;
 
    rdn_to_ymd(rdn, &y, &m, &d);
 
    /*
     *           1
     * 0123456789012345678
     * YYYY-MM-DDThh:mm:ss
     */
    p = (unsigned char*) dst;
    v = sec % 86400;
    p[18] = '0' + (v % 10); v /= 10;
    p[17] = '0' + (v % 6); v /= 6;
    p[16] = ':';
    p[15] = '0' + (v % 10); v /= 10;
    p[14] = '0' + (v % 6); v /= 6;
    p[13] = ':';
    p[12] = '0' + (v % 10); v /= 10;
    p[11] = '0' + (v % 10);
    p[10] = 'T';
    p[ 9] = '0' + (d % 10); d /= 10;
    p[ 8] = '0' + (d % 10);
    p[ 7] = '-';
    p[ 6] = '0' + (m % 10); m /= 10;
    p[ 5] = '0' + (m % 10);
    p[ 4] = '-';
    p[ 3] = '0' + (y % 10); y /= 10;
    p[ 2] = '0' + (y % 10); y /= 10;
    p[ 1] = '0' + (y % 10); y /= 10;
    p[ 0] = '0' + (y % 10);
    p += 19;
 
    if(precision) {
        v = tsp->nsec / Pow10[9 - precision];
        for(int i = precision; i > 0; i--) {
            p[i] = '0' + (v % 10);
            if(i > 1) {
                v /= 10;
            }
        }
        p[0] = '.';
        p += 1 + precision;
    }
 
    if(!tsp->offset) {
        *p++ = 'Z';
    } else {
        if(tsp->offset < 0) {
            p[0] = '-', v = -tsp->offset;
        } else {
            p[0] = '+', v = tsp->offset;
        }
        p[5] = '0' + (v % 10); v /= 10;
        p[4] = '0' + (v % 6); v /= 6;
        p[3] = ':';
        p[2] = '0' + (v % 10); v /= 10;
        p[1] = '0' + (v % 10);
        p += 6;
    }
    *p = 0;
    return dlen;
}

timestamp_to_tm()

static int timestamp_to_tm ( const amxc_ts_t *  tsp, struct tm *  tmp, const bool  local  )

static

Definition at line 272 of file amxc_timestamp.c.

                                             {
    uint64_t sec;
    uint32_t rdn, sod;
    int retval = -1;
 
    when_null(tsp, exit);
    when_null(tmp, exit);
    when_true(!amxc_ts_is_valid(tsp), exit);
 
    sec = tsp->sec + RDN_OFFSET;
    if(local) {
        sec += tsp->offset * 60;
    }
    rdn = sec / 86400;
    sod = sec % 86400;
 
    rdn_to_struct_tm(rdn, tmp);
    tmp->tm_sec = sod % 60; sod /= 60;
    tmp->tm_min = sod % 60; sod /= 60;
    tmp->tm_hour = sod;
 
    retval = 0;
 
exit:
    return retval;
}

Variable Documentation

DayOffset

const uint16_t DayOffset[13]

static

Initial value:

= {
    0, 306, 337, 0, 31, 61, 92, 122, 153, 184, 214, 245, 275
}

Definition at line 104 of file amxc_timestamp.c.

Pow10

const uint32_t Pow10[10]

static

Initial value:

= {
    1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000
}

Definition at line 100 of file amxc_timestamp.c.