tequilaOS/platform_system_core
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
platform_system_core/libcutils/tztime.c
The Android Open Source Project dd7bc3319d auto import from //depot/cupcake/@135843
2009-03-03 19:32:55 -08:00

1915 lines
47 KiB
C
Raw Blame History

/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/
#include <stdio.h>
#ifndef lint
#ifndef NOID
static char elsieid[] = "@(#)localtime.c 8.3";
#endif /* !defined NOID */
#endif /* !defined lint */
/*
** Leap second handling from Bradley White.
** POSIX-style TZ environment variable handling from Guy Harris.
*/
/*LINTLIBRARY*/
#include "private.h"
#include "tzfile.h"
#include "fcntl.h"
#include "float.h" /* for FLT_MAX and DBL_MAX */
#ifndef TZ_ABBR_MAX_LEN
#define TZ_ABBR_MAX_LEN 16
#endif /* !defined TZ_ABBR_MAX_LEN */
#ifndef TZ_ABBR_CHAR_SET
#define TZ_ABBR_CHAR_SET \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
#endif /* !defined TZ_ABBR_CHAR_SET */
#ifndef TZ_ABBR_ERR_CHAR
#define TZ_ABBR_ERR_CHAR '_'
#endif /* !defined TZ_ABBR_ERR_CHAR */
#define INDEXFILE "/system/usr/share/zoneinfo/zoneinfo.idx"
#define DATAFILE "/system/usr/share/zoneinfo/zoneinfo.dat"
#define NAMELEN 40
#define INTLEN 4
#define READLEN (NAMELEN + 3 * INTLEN)
/*
** SunOS 4.1.1 headers lack O_BINARY.
*/
#ifdef O_BINARY
#define OPEN_MODE (O_RDONLY | O_BINARY)
#endif /* defined O_BINARY */
#ifndef O_BINARY
#define OPEN_MODE O_RDONLY
#endif /* !defined O_BINARY */
#ifndef WILDABBR
/*
** Someone might make incorrect use of a time zone abbreviation:
** 1. They might reference tzname[0] before calling tzset (explicitly
** or implicitly).
** 2. They might reference tzname[1] before calling tzset (explicitly
** or implicitly).
** 3. They might reference tzname[1] after setting to a time zone
** in which Daylight Saving Time is never observed.
** 4. They might reference tzname[0] after setting to a time zone
** in which Standard Time is never observed.
** 5. They might reference tm.TM_ZONE after calling offtime.
** What's best to do in the above cases is open to debate;
** for now, we just set things up so that in any of the five cases
** WILDABBR is used. Another possibility: initialize tzname[0] to the
** string "tzname[0] used before set", and similarly for the other cases.
** And another: initialize tzname[0] to "ERA", with an explanation in the
** manual page of what this "time zone abbreviation" means (doing this so
** that tzname[0] has the "normal" length of three characters).
*/
#define WILDABBR " "
#endif /* !defined WILDABBR */
static char wildabbr[] = WILDABBR;
static const char gmt[] = "GMT";
/*
** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
** We default to US rules as of 1999-08-17.
** POSIX 1003.1 section 8.1.1 says that the default DST rules are
** implementation dependent; for historical reasons, US rules are a
** common default.
*/
#ifndef TZDEFRULESTRING
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#endif /* !defined TZDEFDST */
struct ttinfo { /* time type information */
long tt_gmtoff; /* UTC offset in seconds */
int tt_isdst; /* used to set tm_isdst */
int tt_abbrind; /* abbreviation list index */
int tt_ttisstd; /* TRUE if transition is std time */
int tt_ttisgmt; /* TRUE if transition is UTC */
};
struct lsinfo { /* leap second information */
time_t ls_trans; /* transition time */
long ls_corr; /* correction to apply */
};
#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
#ifdef TZNAME_MAX
#define MY_TZNAME_MAX TZNAME_MAX
#endif /* defined TZNAME_MAX */
#ifndef TZNAME_MAX
#define MY_TZNAME_MAX 255
#endif /* !defined TZNAME_MAX */
struct state {
int leapcnt;
int timecnt;
int typecnt;
int charcnt;
int goback;
int goahead;
time_t ats[TZ_MAX_TIMES];
unsigned char types[TZ_MAX_TIMES];
struct ttinfo ttis[TZ_MAX_TYPES];
char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
(2 * (MY_TZNAME_MAX + 1)))];
struct lsinfo lsis[TZ_MAX_LEAPS];
};
struct rule {
int r_type; /* type of rule--see below */
int r_day; /* day number of rule */
int r_week; /* week number of rule */
int r_mon; /* month number of rule */
long r_time; /* transition time of rule */
};
#define JULIAN_DAY 0 /* Jn - Julian day */
#define DAY_OF_YEAR 1 /* n - day of year */
#define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */
/*
** Prototypes for static functions.
*/
static long detzcode P((const char * codep));
static time_t detzcode64 P((const char * codep));
static int differ_by_repeat P((time_t t1, time_t t0));
static const char * getzname P((const char * strp));
static const char * getqzname P((const char * strp, const int delim));
static const char * getnum P((const char * strp, int * nump, int min,
int max));
static const char * getsecs P((const char * strp, long * secsp));
static const char * getoffset P((const char * strp, long * offsetp));
static const char * getrule P((const char * strp, struct rule * rulep));
static void gmtload P((struct state * sp));
static struct tm * gmtsub P((const time_t * timep, long offset,
struct tm * tmp));
static struct tm * localsub P((const time_t * timep, long offset,
struct tm * tmp, struct state *sp));
static int increment_overflow P((int * number, int delta));
static int leaps_thru_end_of P((int y));
static int long_increment_overflow P((long * number, int delta));
static int long_normalize_overflow P((long * tensptr,
int * unitsptr, int base));
static int normalize_overflow P((int * tensptr, int * unitsptr,
int base));
static void settzname P((void));
static time_t time1 P((struct tm * tmp,
struct tm * (*funcp) P((const time_t *,
long, struct tm *, const struct state* sp)),
long offset, const struct state * sp));
static time_t time2 P((struct tm *tmp,
struct tm * (*funcp) P((const time_t *,
long, struct tm*, const struct state* sp)),
long offset, int * okayp, const struct state * sp));
static time_t time2sub P((struct tm *tmp,
struct tm * (*funcp) P((const time_t*, long, struct tm*,const struct state *sp)),
long offset, int * okayp, int do_norm_secs,
const struct state *sp));
static struct tm * timesub P((const time_t * timep, long offset,
const struct state * sp, struct tm * tmp));
static int tmcomp P((const struct tm * atmp,
const struct tm * btmp));
static time_t transtime P((time_t janfirst, int year,
const struct rule * rulep, long offset));
static int tzload P((const char * name, struct state * sp,
int doextend));
static int tzload_uncached P((const char * name, struct state * sp,
int doextend));
static int tzparse P((const char * name, struct state * sp,
int lastditch));
#ifdef ALL_STATE
static struct state * gmtptr;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
static struct state gmtmem;
#define gmtptr (&gmtmem)
#endif /* State Farm */
#define CACHE_COUNT 4
static char * g_cacheNames[CACHE_COUNT] = {0,0};
static struct state g_cacheStates[CACHE_COUNT];
static int g_lastCache = 0;
static struct state g_utc;
unsigned char g_utcSet = 0;
#ifndef TZ_STRLEN_MAX
#define TZ_STRLEN_MAX 255
#endif /* !defined TZ_STRLEN_MAX */
static char lcl_TZname[TZ_STRLEN_MAX + 1];
static int lcl_is_set;
static int gmt_is_set;
char * tzname[2] = {
wildabbr,
wildabbr
};
/*
** Section 4.12.3 of X3.159-1989 requires that
** Except for the strftime function, these functions [asctime,
** ctime, gmtime, localtime] return values in one of two static
** objects: a broken-down time structure and an array of char.
** Thanks to Paul Eggert for noting this.
*/
static struct tm tm;
#ifdef USG_COMPAT
time_t timezone = 0;
int daylight = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
time_t altzone = 0;
#endif /* defined ALTZONE */
static long
detzcode(codep)
const char * const codep;
{
register long result;
register int i;
result = (codep[0] & 0x80) ? ~0L : 0;
for (i = 0; i < 4; ++i)
result = (result << 8) | (codep[i] & 0xff);
return result;
}
static time_t
detzcode64(codep)
const char * const codep;
{
register time_t result;
register int i;
result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0;
for (i = 0; i < 8; ++i)
result = result * 256 + (codep[i] & 0xff);
return result;
}
static int
differ_by_repeat(t1, t0)
const time_t t1;
const time_t t0;
{
if (TYPE_INTEGRAL(time_t) &&
TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
return 0;
return t1 - t0 == SECSPERREPEAT;
}
static int toint(unsigned char *s) {
return (s[0] << 24) | (s[1] << 16) | (s[2] << 8) | s[3];
}
static int
tzload(const char *name, struct state * const sp, const int doextend)
{
if (name) {
int i, err;
if (0 == strcmp(name, "UTC")) {
if (!g_utcSet) {
tzload_uncached(name, &g_utc, 1);
g_utcSet = 1;
}
//printf("tzload: utc\n");
*sp = g_utc;
return 0;
}
for (i=0; i<CACHE_COUNT; i++) {
if (g_cacheNames[i] && 0 == strcmp(name, g_cacheNames[i])) {
*sp = g_cacheStates[i];
//printf("tzload: hit: %s\n", name);
return 0;
}
}
//printf("tzload: miss: %s\n", name);
g_lastCache++;
if (g_lastCache >= CACHE_COUNT) {
g_lastCache = 0;
}
i = g_lastCache;
if (g_cacheNames[i]) {
free(g_cacheNames[i]);
}
err = tzload_uncached(name, &(g_cacheStates[i]), 1);
if (err == 0) {
g_cacheNames[i] = strdup(name);
*sp = g_cacheStates[i];
return 0;
} else {
g_cacheNames[i] = NULL;
return err;
}
}
return tzload_uncached(name, sp, doextend);
}
static int
tzload_uncached(name, sp, doextend)
register const char * name;
register struct state * const sp;
register const int doextend;
{
register const char * p;
register int i;
register int fid;
register int stored;
register int nread;
union {
struct tzhead tzhead;
char buf[2 * sizeof(struct tzhead) +
2 * sizeof *sp +
4 * TZ_MAX_TIMES];
} u;
int toread = sizeof u.buf;
if (name == NULL && (name = TZDEFAULT) == NULL)
return -1;
{
register int doaccess;
/*
** Section 4.9.1 of the C standard says that
** "FILENAME_MAX expands to an integral constant expression
** that is the size needed for an array of char large enough
** to hold the longest file name string that the implementation
** guarantees can be opened."
*/
char fullname[FILENAME_MAX + 1];
const char *origname = name;
if (name[0] == ':')
++name;
doaccess = name[0] == '/';
if (!doaccess) {
if ((p = TZDIR) == NULL)
return -1;
if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
return -1;
(void) strcpy(fullname, p);
(void) strcat(fullname, "/");
(void) strcat(fullname, name);
/*
** Set doaccess if '.' (as in "../") shows up in name.
*/
if (strchr(name, '.') != NULL)
doaccess = TRUE;
name = fullname;
}
if (doaccess && access(name, R_OK) != 0)
return -1;
if ((fid = open(name, OPEN_MODE)) == -1) {
char buf[READLEN];
char name[NAMELEN + 1];
int fidix = open(INDEXFILE, OPEN_MODE);
int off = -1;
if (fidix < 0) {
return -1;
}
while (read(fidix, buf, sizeof(buf)) == sizeof(buf)) {
memcpy(name, buf, NAMELEN);
name[NAMELEN] = '\0';
if (strcmp(name, origname) == 0) {
off = toint((unsigned char *) buf + NAMELEN);
toread = toint((unsigned char *) buf + NAMELEN + INTLEN);
break;
}
}
close(fidix);
if (off < 0)
return -1;
fid = open(DATAFILE, OPEN_MODE);
if (fid < 0) {
return -1;
}
if (lseek(fid, off, SEEK_SET) < 0) {
return -1;
}
}
}
nread = read(fid, u.buf, toread);
if (close(fid) < 0 || nread <= 0)
return -1;
for (stored = 4; stored <= 8; stored *= 2) {
int ttisstdcnt;
int ttisgmtcnt;
ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
return -1;
if (nread - (p - u.buf) <
sp->timecnt * stored + /* ats */
sp->timecnt + /* types */
sp->typecnt * 6 + /* ttinfos */
sp->charcnt + /* chars */
sp->leapcnt * (stored + 4) + /* lsinfos */
ttisstdcnt + /* ttisstds */
ttisgmtcnt) /* ttisgmts */
return -1;
for (i = 0; i < sp->timecnt; ++i) {
sp->ats[i] = (stored == 4) ?
detzcode(p) : detzcode64(p);
p += stored;
}
for (i = 0; i < sp->timecnt; ++i) {
sp->types[i] = (unsigned char) *p++;
if (sp->types[i] >= sp->typecnt)
return -1;
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
ttisp->tt_gmtoff = detzcode(p);
p += 4;
ttisp->tt_isdst = (unsigned char) *p++;
if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
return -1;
ttisp->tt_abbrind = (unsigned char) *p++;
if (ttisp->tt_abbrind < 0 ||
ttisp->tt_abbrind > sp->charcnt)
return -1;
}
for (i = 0; i < sp->charcnt; ++i)
sp->chars[i] = *p++;
sp->chars[i] = '\0'; /* ensure '\0' at end */
for (i = 0; i < sp->leapcnt; ++i) {
register struct lsinfo * lsisp;
lsisp = &sp->lsis[i];
lsisp->ls_trans = (stored == 4) ?
detzcode(p) : detzcode64(p);
p += stored;
lsisp->ls_corr = detzcode(p);
p += 4;
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
if (ttisstdcnt == 0)
ttisp->tt_ttisstd = FALSE;
else {
ttisp->tt_ttisstd = *p++;
if (ttisp->tt_ttisstd != TRUE &&
ttisp->tt_ttisstd != FALSE)
return -1;
}
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
if (ttisgmtcnt == 0)
ttisp->tt_ttisgmt = FALSE;
else {
ttisp->tt_ttisgmt = *p++;
if (ttisp->tt_ttisgmt != TRUE &&
ttisp->tt_ttisgmt != FALSE)
return -1;
}
}
/*
** Out-of-sort ats should mean we're running on a
** signed time_t system but using a data file with
** unsigned values (or vice versa).
*/
for (i = 0; i < sp->timecnt - 2; ++i)
if (sp->ats[i] > sp->ats[i + 1]) {
++i;
if (TYPE_SIGNED(time_t)) {
/*
** Ignore the end (easy).
*/
sp->timecnt = i;
} else {
/*
** Ignore the beginning (harder).
*/
register int j;
for (j = 0; j + i < sp->timecnt; ++j) {
sp->ats[j] = sp->ats[j + i];
sp->types[j] = sp->types[j + i];
}
sp->timecnt = j;
}
break;
}
/*
** If this is an old file, we're done.
*/
if (u.tzhead.tzh_version[0] == '\0')
break;
nread -= p - u.buf;
for (i = 0; i < nread; ++i)
u.buf[i] = p[i];
/*
** If this is a narrow integer time_t system, we're done.
*/
if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
break;
}
if (doextend && nread > 2 &&
u.buf[0] == '\n' && u.buf[nread - 1] == '\n' &&
sp->typecnt + 2 <= TZ_MAX_TYPES) {
struct state ts;
register int result;
u.buf[nread - 1] = '\0';
result = tzparse(&u.buf[1], &ts, FALSE);
if (result == 0 && ts.typecnt == 2 &&
sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
for (i = 0; i < 2; ++i)
ts.ttis[i].tt_abbrind +=
sp->charcnt;
for (i = 0; i < ts.charcnt; ++i)
sp->chars[sp->charcnt++] =
ts.chars[i];
i = 0;
while (i < ts.timecnt &&
ts.ats[i] <=
sp->ats[sp->timecnt - 1])
++i;
while (i < ts.timecnt &&
sp->timecnt < TZ_MAX_TIMES) {
sp->ats[sp->timecnt] =
ts.ats[i];
sp->types[sp->timecnt] =
sp->typecnt +
ts.types[i];
++sp->timecnt;
++i;
}
sp->ttis[sp->typecnt++] = ts.ttis[0];
sp->ttis[sp->typecnt++] = ts.ttis[1];
}
}
i = 2 * YEARSPERREPEAT;
sp->goback = sp->goahead = sp->timecnt > i;
sp->goback &= sp->types[i] == sp->types[0] &&
differ_by_repeat(sp->ats[i], sp->ats[0]);
sp->goahead &=
sp->types[sp->timecnt - 1] == sp->types[sp->timecnt - 1 - i] &&
differ_by_repeat(sp->ats[sp->timecnt - 1],
sp->ats[sp->timecnt - 1 - i]);
return 0;
}
static const int mon_lengths[2][MONSPERYEAR] = {
{ 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 int year_lengths[2] = {
DAYSPERNYEAR, DAYSPERLYEAR
};
/*
** Given a pointer into a time zone string, scan until a character that is not
** a valid character in a zone name is found. Return a pointer to that
** character.
*/
static const char *
getzname(strp)
register const char * strp;
{
register char c;
while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
c != '+')
++strp;
return strp;
}
/*
** Given a pointer into an extended time zone string, scan until the ending
** delimiter of the zone name is located. Return a pointer to the delimiter.
**
** As with getzname above, the legal character set is actually quite
** restricted, with other characters producing undefined results.
** We don't do any checking here; checking is done later in common-case code.
*/
static const char *
getqzname(register const char *strp, const int delim)
{
register int c;
while ((c = *strp) != '\0' && c != delim)
++strp;
return strp;
}
/*
** Given a pointer into a time zone string, extract a number from that string.
** Check that the number is within a specified range; if it is not, return
** NULL.
** Otherwise, return a pointer to the first character not part of the number.
*/
static const char *
getnum(strp, nump, min, max)
register const char * strp;
int * const nump;
const int min;
const int max;
{
register char c;
register int num;
if (strp == NULL || !is_digit(c = *strp))
return NULL;
num = 0;
do {
num = num * 10 + (c - '0');
if (num > max)
return NULL; /* illegal value */
c = *++strp;
} while (is_digit(c));
if (num < min)
return NULL; /* illegal value */
*nump = num;
return strp;
}
/*
** Given a pointer into a time zone string, extract a number of seconds,
** in hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the number
** of seconds.
*/
static const char *
getsecs(strp, secsp)
register const char * strp;
long * const secsp;
{
int num;
/*
** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
** "M10.4.6/26", which does not conform to Posix,
** but which specifies the equivalent of
** ``02:00 on the first Sunday on or after 23 Oct''.
*/
strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
if (strp == NULL)
return NULL;
*secsp = num * (long) SECSPERHOUR;
if (*strp == ':') {
++strp;
strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
if (strp == NULL)
return NULL;
*secsp += num * SECSPERMIN;
if (*strp == ':') {
++strp;
/* `SECSPERMIN' allows for leap seconds. */
strp = getnum(strp, &num, 0, SECSPERMIN);
if (strp == NULL)
return NULL;
*secsp += num;
}
}
return strp;
}
/*
** Given a pointer into a time zone string, extract an offset, in
** [+-]hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the time.
*/
static const char *
getoffset(strp, offsetp)
register const char * strp;
long * const offsetp;
{
register int neg = 0;
if (*strp == '-') {
neg = 1;
++strp;
} else if (*strp == '+')
++strp;
strp = getsecs(strp, offsetp);
if (strp == NULL)
return NULL; /* illegal time */
if (neg)
*offsetp = -*offsetp;
return strp;
}
/*
** Given a pointer into a time zone string, extract a rule in the form
** date[/time]. See POSIX section 8 for the format of "date" and "time".
** If a valid rule is not found, return NULL.
** Otherwise, return a pointer to the first character not part of the rule.
*/
static const char *
getrule(strp, rulep)
const char * strp;
register struct rule * const rulep;
{
if (*strp == 'J') {
/*
** Julian day.
*/
rulep->r_type = JULIAN_DAY;
++strp;
strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
} else if (*strp == 'M') {
/*
** Month, week, day.
*/
rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
++strp;
strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
if (strp == NULL)
return NULL;
if (*strp++ != '.')
return NULL;
strp = getnum(strp, &rulep->r_week, 1, 5);
if (strp == NULL)
return NULL;
if (*strp++ != '.')
return NULL;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
} else if (is_digit(*strp)) {
/*
** Day of year.
*/
rulep->r_type = DAY_OF_YEAR;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
} else return NULL; /* invalid format */
if (strp == NULL)
return NULL;
if (*strp == '/') {
/*
** Time specified.
*/
++strp;
strp = getsecs(strp, &rulep->r_time);
} else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
return strp;
}
/*
** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
** year, a rule, and the offset from UTC at the time that rule takes effect,
** calculate the Epoch-relative time that rule takes effect.
*/
static time_t
transtime(janfirst, year, rulep, offset)
const time_t janfirst;
const int year;
register const struct rule * const rulep;
const long offset;
{
register int leapyear;
register time_t value;
register int i;
int d, m1, yy0, yy1, yy2, dow;
INITIALIZE(value);
leapyear = isleap(year);
switch (rulep->r_type) {
case JULIAN_DAY:
/*
** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
** years.
** In non-leap years, or if the day number is 59 or less, just
** add SECSPERDAY times the day number-1 to the time of
** January 1, midnight, to get the day.
*/
value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
if (leapyear && rulep->r_day >= 60)
value += SECSPERDAY;
break;
case DAY_OF_YEAR:
/*
** n - day of year.
** Just add SECSPERDAY times the day number to the time of
** January 1, midnight, to get the day.
*/
value = janfirst + rulep->r_day * SECSPERDAY;
break;
case MONTH_NTH_DAY_OF_WEEK:
/*
** Mm.n.d - nth "dth day" of month m.
*/
value = janfirst;
for (i = 0; i < rulep->r_mon - 1; ++i)
value += mon_lengths[leapyear][i] * SECSPERDAY;
/*
** Use Zeller's Congruence to get day-of-week of first day of
** month.
*/
m1 = (rulep->r_mon + 9) % 12 + 1;
yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
yy1 = yy0 / 100;
yy2 = yy0 % 100;
dow = ((26 * m1 - 2) / 10 +
1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
if (dow < 0)
dow += DAYSPERWEEK;
/*
** "dow" is the day-of-week of the first day of the month. Get
** the day-of-month (zero-origin) of the first "dow" day of the
** month.
*/
d = rulep->r_day - dow;
if (d < 0)
d += DAYSPERWEEK;
for (i = 1; i < rulep->r_week; ++i) {
if (d + DAYSPERWEEK >=
mon_lengths[leapyear][rulep->r_mon - 1])
break;
d += DAYSPERWEEK;
}
/*
** "d" is the day-of-month (zero-origin) of the day we want.
*/
value += d * SECSPERDAY;
break;
}
/*
** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
** question. To get the Epoch-relative time of the specified local
** time on that day, add the transition time and the current offset
** from UTC.
*/
return value + rulep->r_time + offset;
}
/*
** Given a POSIX section 8-style TZ string, fill in the rule tables as
** appropriate.
*/
static int
tzparse(name, sp, lastditch)
const char * name;
register struct state * const sp;
const int lastditch;
{
const char * stdname;
const char * dstname;
size_t stdlen;
size_t dstlen;
long stdoffset;
long dstoffset;
register time_t * atp;
register unsigned char * typep;
register char * cp;
register int load_result;
INITIALIZE(dstname);
stdname = name;
if (lastditch) {
stdlen = strlen(name); /* length of standard zone name */
name += stdlen;
if (stdlen >= sizeof sp->chars)
stdlen = (sizeof sp->chars) - 1;
stdoffset = 0;
} else {
if (*name == '<') {
name++;
stdname = name;
name = getqzname(name, '>');
if (*name != '>')
return (-1);
stdlen = name - stdname;
name++;
} else {
name = getzname(name);
stdlen = name - stdname;
}
if (*name == '\0')
return -1;
name = getoffset(name, &stdoffset);
if (name == NULL)
return -1;
}
load_result = tzload(TZDEFRULES, sp, FALSE);
if (load_result != 0)
sp->leapcnt = 0; /* so, we're off a little */
sp->timecnt = 0;
if (*name != '\0') {
if (*name == '<') {
dstname = ++name;
name = getqzname(name, '>');
if (*name != '>')
return -1;
dstlen = name - dstname;
name++;
} else {
dstname = name;
name = getzname(name);
dstlen = name - dstname; /* length of DST zone name */
}
if (*name != '\0' && *name != ',' && *name != ';') {
name = getoffset(name, &dstoffset);
if (name == NULL)
return -1;
} else dstoffset = stdoffset - SECSPERHOUR;
if (*name == '\0' && load_result != 0)
name = TZDEFRULESTRING;
if (*name == ',' || *name == ';') {
struct rule start;
struct rule end;
register int year;
register time_t janfirst;
time_t starttime;
time_t endtime;
++name;
if ((name = getrule(name, &start)) == NULL)
return -1;
if (*name++ != ',')
return -1;
if ((name = getrule(name, &end)) == NULL)
return -1;
if (*name != '\0')
return -1;
sp->typecnt = 2; /* standard time and DST */
/*
** Two transitions per year, from EPOCH_YEAR forward.
*/
sp->ttis[0].tt_gmtoff = -dstoffset;
sp->ttis[0].tt_isdst = 1;
sp->ttis[0].tt_abbrind = stdlen + 1;
sp->ttis[1].tt_gmtoff = -stdoffset;
sp->ttis[1].tt_isdst = 0;
sp->ttis[1].tt_abbrind = 0;
atp = sp->ats;
typep = sp->types;
janfirst = 0;
for (year = EPOCH_YEAR;
sp->timecnt + 2 <= TZ_MAX_TIMES;
++year) {
time_t newfirst;
starttime = transtime(janfirst, year, &start,
stdoffset);
endtime = transtime(janfirst, year, &end,
dstoffset);
if (starttime > endtime) {
*atp++ = endtime;
*typep++ = 1; /* DST ends */
*atp++ = starttime;
*typep++ = 0; /* DST begins */
} else {
*atp++ = starttime;
*typep++ = 0; /* DST begins */
*atp++ = endtime;
*typep++ = 1; /* DST ends */
}
sp->timecnt += 2;
newfirst = janfirst;
newfirst += year_lengths[isleap(year)] *
SECSPERDAY;
if (newfirst <= janfirst)
break;
janfirst = newfirst;
}
} else {
register long theirstdoffset;
register long theirdstoffset;
register long theiroffset;
register int isdst;
register int i;
register int j;
if (*name != '\0')
return -1;
/*
** Initial values of theirstdoffset and theirdstoffset.
*/
theirstdoffset = 0;
for (i = 0; i < sp->timecnt; ++i) {
j = sp->types[i];
if (!sp->ttis[j].tt_isdst) {
theirstdoffset =
-sp->ttis[j].tt_gmtoff;
break;
}
}
theirdstoffset = 0;
for (i = 0; i < sp->timecnt; ++i) {
j = sp->types[i];
if (sp->ttis[j].tt_isdst) {
theirdstoffset =
-sp->ttis[j].tt_gmtoff;
break;
}
}
/*
** Initially we're assumed to be in standard time.
*/
isdst = FALSE;
theiroffset = theirstdoffset;
/*
** Now juggle transition times and types
** tracking offsets as you do.
*/
for (i = 0; i < sp->timecnt; ++i) {
j = sp->types[i];
sp->types[i] = sp->ttis[j].tt_isdst;
if (sp->ttis[j].tt_ttisgmt) {
/* No adjustment to transition time */
} else {
/*
** If summer time is in effect, and the
** transition time was not specified as
** standard time, add the summer time
** offset to the transition time;
** otherwise, add the standard time
** offset to the transition time.
*/
/*
** Transitions from DST to DDST
** will effectively disappear since
** POSIX provides for only one DST
** offset.
*/
if (isdst && !sp->ttis[j].tt_ttisstd) {
sp->ats[i] += dstoffset -
theirdstoffset;
} else {
sp->ats[i] += stdoffset -
theirstdoffset;
}
}
theiroffset = -sp->ttis[j].tt_gmtoff;
if (sp->ttis[j].tt_isdst)
theirdstoffset = theiroffset;
else theirstdoffset = theiroffset;
}
/*
** Finally, fill in ttis.
** ttisstd and ttisgmt need not be handled.
*/
sp->ttis[0].tt_gmtoff = -stdoffset;
sp->ttis[0].tt_isdst = FALSE;
sp->ttis[0].tt_abbrind = 0;
sp->ttis[1].tt_gmtoff = -dstoffset;
sp->ttis[1].tt_isdst = TRUE;
sp->ttis[1].tt_abbrind = stdlen + 1;
sp->typecnt = 2;
}
} else {
dstlen = 0;
sp->typecnt = 1; /* only standard time */
sp->timecnt = 0;
sp->ttis[0].tt_gmtoff = -stdoffset;
sp->ttis[0].tt_isdst = 0;
sp->ttis[0].tt_abbrind = 0;
}
sp->charcnt = stdlen + 1;
if (dstlen != 0)
sp->charcnt += dstlen + 1;
if ((size_t) sp->charcnt > sizeof sp->chars)
return -1;
cp = sp->chars;
(void) strncpy(cp, stdname, stdlen);
cp += stdlen;
*cp++ = '\0';
if (dstlen != 0) {
(void) strncpy(cp, dstname, dstlen);
*(cp + dstlen) = '\0';
}
return 0;
}
static void
gmtload(sp)
struct state * const sp;
{
if (tzload(gmt, sp, TRUE) != 0)
(void) tzparse(gmt, sp, TRUE);
}
/*
** The easy way to behave "as if no library function calls" localtime
** is to not call it--so we drop its guts into "localsub", which can be
** freely called. (And no, the PANS doesn't require the above behavior--
** but it *is* desirable.)
**
** The unused offset argument is for the benefit of mktime variants.
*/
/*ARGSUSED*/
static struct tm *
localsub(timep, offset, tmp, sp)
const time_t * const timep;
const long offset;
struct tm * const tmp;
struct state * sp;
{
register const struct ttinfo * ttisp;
register int i;
register struct tm * result;
const time_t t = *timep;
#ifdef ALL_STATE
if (sp == NULL)
return gmtsub(timep, offset, tmp);
#endif /* defined ALL_STATE */
if ((sp->goback && t < sp->ats[0]) ||
(sp->goahead && t > sp->ats[sp->timecnt - 1])) {
time_t newt = t;
register time_t seconds;
register time_t tcycles;
register int_fast64_t icycles;
if (t < sp->ats[0])
seconds = sp->ats[0] - t;
else seconds = t - sp->ats[sp->timecnt - 1];
--seconds;
tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
++tcycles;
icycles = tcycles;
if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
return NULL;
seconds = icycles;
seconds *= YEARSPERREPEAT;
seconds *= AVGSECSPERYEAR;
if (t < sp->ats[0])
newt += seconds;
else newt -= seconds;
if (newt < sp->ats[0] ||
newt > sp->ats[sp->timecnt - 1])
return NULL; /* "cannot happen" */
result = localsub(&newt, offset, tmp, sp);
if (result == tmp) {
register time_t newy;
newy = tmp->tm_year;
if (t < sp->ats[0])
newy -= icycles * YEARSPERREPEAT;
else newy += icycles * YEARSPERREPEAT;
tmp->tm_year = newy;
if (tmp->tm_year != newy)
return NULL;
}
return result;
}
if (sp->timecnt == 0 || t < sp->ats[0]) {
i = 0;
while (sp->ttis[i].tt_isdst)
if (++i >= sp->typecnt) {
i = 0;
break;
}
} else {
register int lo = 1;
register int hi = sp->timecnt;
while (lo < hi) {
register int mid = (lo + hi) >> 1;
if (t < sp->ats[mid])
hi = mid;
else lo = mid + 1;
}
i = (int) sp->types[lo - 1];
}
ttisp = &sp->ttis[i];
/*
** To get (wrong) behavior that's compatible with System V Release 2.0
** you'd replace the statement below with
** t += ttisp->tt_gmtoff;
** timesub(&t, 0L, sp, tmp);
*/
result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
tmp->tm_isdst = ttisp->tt_isdst;
#ifdef HAVE_TM_GMTOFF
tmp->tm_gmtoff = ttisp->tt_gmtoff;
#endif
tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
#ifdef TM_ZONE
tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
#endif /* defined TM_ZONE */
return result;
}
// ============================================================================
#if 0
struct tm *
localtime(timep)
const time_t * const timep;
{
tzset();
return localsub(timep, 0L, &tm);
}
#endif
/*
** Re-entrant version of localtime.
*/
// ============================================================================
void
localtime_tz(const time_t * const timep, struct tm * tmp, const char* tz)
{
struct state st;
if (tzload(tz, &st, TRUE) != 0) {
// not sure what's best here, but for now, we fall back to gmt
gmtload(&st);
}
localsub(timep, 0L, tmp, &st);
}
/*
** gmtsub is to gmtime as localsub is to localtime.
*/
static struct tm *
gmtsub(timep, offset, tmp)
const time_t * const timep;
const long offset;
struct tm * const tmp;
{
register struct tm * result;
if (!gmt_is_set) {
gmt_is_set = TRUE;
#ifdef ALL_STATE
gmtptr = (struct state *) malloc(sizeof *gmtptr);
if (gmtptr != NULL)
#endif /* defined ALL_STATE */
gmtload(gmtptr);
}
result = timesub(timep, offset, gmtptr, tmp);
#ifdef TM_ZONE
/*
** Could get fancy here and deliver something such as
** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
** but this is no time for a treasure hunt.
*/
if (offset != 0)
tmp->TM_ZONE = wildabbr;
else {
#ifdef ALL_STATE
if (gmtptr == NULL)
tmp->TM_ZONE = gmt;
else tmp->TM_ZONE = gmtptr->chars;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
tmp->TM_ZONE = gmtptr->chars;
#endif /* State Farm */
}
#endif /* defined TM_ZONE */
return result;
}
// ============================================================================
#if 0
struct tm *
gmtime(timep)
const time_t * const timep;
{
return gmtsub(timep, 0L, &tm);
}
#endif
/*
* Re-entrant version of gmtime.
*/
// ============================================================================
#if 0
struct tm *
gmtime_r(timep, tmp)
const time_t * const timep;
struct tm * tmp;
{
return gmtsub(timep, 0L, tmp);
}
#endif
#ifdef STD_INSPIRED
// ============================================================================
#if 0
struct tm *
offtime(timep, offset)
const time_t * const timep;
const long offset;
{
return gmtsub(timep, offset, &tm);
}
#endif
#endif /* defined STD_INSPIRED */
/*
** Return the number of leap years through the end of the given year
** where, to make the math easy, the answer for year zero is defined as zero.
*/
static int
leaps_thru_end_of(y)
register const int y;
{
return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
-(leaps_thru_end_of(-(y + 1)) + 1);
}
static struct tm *
timesub(timep, offset, sp, tmp)
const time_t * const timep;
const long offset;
register const struct state * const sp;
register struct tm * const tmp;
{
register const struct lsinfo * lp;
register time_t tdays;
register int idays; /* unsigned would be so 2003 */
register long rem;
int y;
register const int * ip;
register long corr;
register int hit;
register int i;
corr = 0;
hit = 0;
#ifdef ALL_STATE
i = (sp == NULL) ? 0 : sp->leapcnt;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
i = sp->leapcnt;
#endif /* State Farm */
while (--i >= 0) {
lp = &sp->lsis[i];
if (*timep >= lp->ls_trans) {
if (*timep == lp->ls_trans) {
hit = ((i == 0 && lp->ls_corr > 0) ||
lp->ls_corr > sp->lsis[i - 1].ls_corr);
if (hit)
while (i > 0 &&
sp->lsis[i].ls_trans ==
sp->lsis[i - 1].ls_trans + 1 &&
sp->lsis[i].ls_corr ==
sp->lsis[i - 1].ls_corr + 1) {
++hit;
--i;
}
}
corr = lp->ls_corr;
break;
}
}
y = EPOCH_YEAR;
tdays = *timep / SECSPERDAY;
rem = *timep - tdays * SECSPERDAY;
while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
int newy;
register time_t tdelta;
register int idelta;
register int leapdays;
tdelta = tdays / DAYSPERLYEAR;
idelta = tdelta;
if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
return NULL;
if (idelta == 0)
idelta = (tdays < 0) ? -1 : 1;
newy = y;
if (increment_overflow(&newy, idelta))
return NULL;
leapdays = leaps_thru_end_of(newy - 1) -
leaps_thru_end_of(y - 1);
tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
tdays -= leapdays;
y = newy;
}
{
register long seconds;
seconds = tdays * SECSPERDAY + 0.5;
tdays = seconds / SECSPERDAY;
rem += seconds - tdays * SECSPERDAY;
}
/*
** Given the range, we can now fearlessly cast...
*/
idays = tdays;
rem += offset - corr;
while (rem < 0) {
rem += SECSPERDAY;
--idays;
}
while (rem >= SECSPERDAY) {
rem -= SECSPERDAY;
++idays;
}
while (idays < 0) {
if (increment_overflow(&y, -1))
return NULL;
idays += year_lengths[isleap(y)];
}
while (idays >= year_lengths[isleap(y)]) {
idays -= year_lengths[isleap(y)];
if (increment_overflow(&y, 1))
return NULL;
}
tmp->tm_year = y;
if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
return NULL;
tmp->tm_yday = idays;
/*
** The "extra" mods below avoid overflow problems.
*/
tmp->tm_wday = EPOCH_WDAY +
((y - EPOCH_YEAR) % DAYSPERWEEK) *
(DAYSPERNYEAR % DAYSPERWEEK) +
leaps_thru_end_of(y - 1) -
leaps_thru_end_of(EPOCH_YEAR - 1) +
idays;
tmp->tm_wday %= DAYSPERWEEK;
if (tmp->tm_wday < 0)
tmp->tm_wday += DAYSPERWEEK;
tmp->tm_hour = (int) (rem / SECSPERHOUR);
rem %= SECSPERHOUR;
tmp->tm_min = (int) (rem / SECSPERMIN);
/*
** A positive leap second requires a special
** representation. This uses "... ??:59:60" et seq.
*/
tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
ip = mon_lengths[isleap(y)];
for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
idays -= ip[tmp->tm_mon];
tmp->tm_mday = (int) (idays + 1);
tmp->tm_isdst = 0;
#ifdef TM_GMTOFF
tmp->TM_GMTOFF = offset;
#endif /* defined TM_GMTOFF */
return tmp;
}
// ============================================================================
#if 0
char *
ctime(timep)
const time_t * const timep;
{
/*
** Section 4.12.3.2 of X3.159-1989 requires that
** The ctime function converts the calendar time pointed to by timer
** to local time in the form of a string. It is equivalent to
** asctime(localtime(timer))
*/
return asctime(localtime(timep));
}
#endif
// ============================================================================
#if 0
char *
ctime_r(timep, buf)
const time_t * const timep;
char * buf;
{
struct tm mytm;
return asctime_r(localtime_r(timep, &mytm), buf);
}
#endif
/*
** Adapted from code provided by Robert Elz, who writes:
** The "best" way to do mktime I think is based on an idea of Bob
** Kridle's (so its said...) from a long time ago.
** It does a binary search of the time_t space. Since time_t's are
** just 32 bits, its a max of 32 iterations (even at 64 bits it
** would still be very reasonable).
*/
#ifndef WRONG
#define WRONG (-1)
#endif /* !defined WRONG */
/*
** Simplified normalize logic courtesy Paul Eggert.
*/
static int
increment_overflow(number, delta)
int * number;
int delta;
{
int number0;
number0 = *number;
*number += delta;
return (*number < number0) != (delta < 0);
}
static int
long_increment_overflow(number, delta)
long * number;
int delta;
{
long number0;
number0 = *number;
*number += delta;
return (*number < number0) != (delta < 0);
}
static int
normalize_overflow(tensptr, unitsptr, base)
int * const tensptr;
int * const unitsptr;
const int base;
{
register int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) :
(-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow(tensptr, tensdelta);
}
static int
long_normalize_overflow(tensptr, unitsptr, base)
long * const tensptr;
int * const unitsptr;
const int base;
{
register int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) :
(-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return long_increment_overflow(tensptr, tensdelta);
}
static int
tmcomp(atmp, btmp)
register const struct tm * const atmp;
register const struct tm * const btmp;
{
register int result;
if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
(result = (atmp->tm_min - btmp->tm_min)) == 0)
result = atmp->tm_sec - btmp->tm_sec;
return result;
}
static time_t
time2sub(tmp, funcp, offset, okayp, do_norm_secs, sp)
struct tm * const tmp;
struct tm * (* const funcp) P((const time_t*, long, struct tm*,const struct state *sp));
const long offset;
int * const okayp;
const int do_norm_secs;
const struct state * sp;
{
register int dir;
register int i, j;
register int saved_seconds;
register long li;
register time_t lo;
register time_t hi;
long y;
time_t newt;
time_t t;
struct tm yourtm, mytm;
*okayp = FALSE;
yourtm = *tmp;
if (do_norm_secs) {
if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
SECSPERMIN))
return WRONG;
}
if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
return WRONG;
if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
return WRONG;
y = yourtm.tm_year;
if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR))
return WRONG;
/*
** Turn y into an actual year number for now.
** It is converted back to an offset from TM_YEAR_BASE later.
*/
if (long_increment_overflow(&y, TM_YEAR_BASE))
return WRONG;
while (yourtm.tm_mday <= 0) {
if (long_increment_overflow(&y, -1))
return WRONG;
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday += year_lengths[isleap(li)];
}
while (yourtm.tm_mday > DAYSPERLYEAR) {
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday -= year_lengths[isleap(li)];
if (long_increment_overflow(&y, 1))
return WRONG;
}
for ( ; ; ) {
i = mon_lengths[isleap(y)][yourtm.tm_mon];
if (yourtm.tm_mday <= i)
break;
yourtm.tm_mday -= i;
if (++yourtm.tm_mon >= MONSPERYEAR) {
yourtm.tm_mon = 0;
if (long_increment_overflow(&y, 1))
return WRONG;
}
}
if (long_increment_overflow(&y, -TM_YEAR_BASE))
return WRONG;
yourtm.tm_year = y;
if (yourtm.tm_year != y)
return WRONG;
if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
saved_seconds = 0;
else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
/*
** We can't set tm_sec to 0, because that might push the
** time below the minimum representable time.
** Set tm_sec to 59 instead.
** This assumes that the minimum representable time is
** not in the same minute that a leap second was deleted from,
** which is a safer assumption than using 58 would be.
*/
if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
return WRONG;
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = SECSPERMIN - 1;
} else {
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = 0;
}
/*
** Do a binary search (this works whatever time_t's type is).
*/
if (!TYPE_SIGNED(time_t)) {
lo = 0;
hi = lo - 1;
} else if (!TYPE_INTEGRAL(time_t)) {
if (sizeof(time_t) > sizeof(float))
hi = (time_t) DBL_MAX;
else hi = (time_t) FLT_MAX;
lo = -hi;
} else {
lo = 1;
for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
lo *= 2;
hi = -(lo + 1);
}
for ( ; ; ) {
t = lo / 2 + hi / 2;
if (t < lo)
t = lo;
else if (t > hi)
t = hi;
if ((*funcp)(&t, offset, &mytm, sp) == NULL) {
/*
** Assume that t is too extreme to be represented in
** a struct tm; arrange things so that it is less
** extreme on the next pass.
*/
dir = (t > 0) ? 1 : -1;
} else dir = tmcomp(&mytm, &yourtm);
if (dir != 0) {
if (t == lo) {
++t;
if (t <= lo)
return WRONG;
++lo;
} else if (t == hi) {
--t;
if (t >= hi)
return WRONG;
--hi;
}
if (lo > hi)
return WRONG;
if (dir > 0)
hi = t;
else lo = t;
continue;
}
if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
break;
/*
** Right time, wrong type.
** Hunt for right time, right type.
** It's okay to guess wrong since the guess
** gets checked.
*/
/*
** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
*/
#ifdef ALL_STATE
if (sp == NULL)
return WRONG;
#endif /* defined ALL_STATE */
for (i = sp->typecnt - 1; i >= 0; --i) {
if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
continue;
for (j = sp->typecnt - 1; j >= 0; --j) {
if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
continue;
newt = t + sp->ttis[j].tt_gmtoff -
sp->ttis[i].tt_gmtoff;
if ((*funcp)(&newt, offset, &mytm, sp) == NULL)
continue;
if (tmcomp(&mytm, &yourtm) != 0)
continue;
if (mytm.tm_isdst != yourtm.tm_isdst)
continue;
/*
** We have a match.
*/
t = newt;
goto label;
}
}
return WRONG;
}
label:
newt = t + saved_seconds;
if ((newt < t) != (saved_seconds < 0))
return WRONG;
t = newt;
if ((*funcp)(&t, offset, tmp, sp))
*okayp = TRUE;
return t;
}
static time_t
time2(tmp, funcp, offset, okayp, sp)
struct tm * const tmp;
struct tm * (* const funcp) P((const time_t*, long, struct tm*,
const struct state* sp));
const long offset;
int * const okayp;
const struct state * sp;
{
time_t t;
/*
** First try without normalization of seconds
** (in case tm_sec contains a value associated with a leap second).
** If that fails, try with normalization of seconds.
*/
t = time2sub(tmp, funcp, offset, okayp, FALSE, sp);
return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE, sp);
}
static time_t
time1(tmp, funcp, offset, sp)
struct tm * const tmp;
struct tm * (* const funcp) P((const time_t *, long, struct tm *, const struct state* sp));
const long offset;
const struct state * sp;
{
register time_t t;
register int samei, otheri;
register int sameind, otherind;
register int i;
register int nseen;
int seen[TZ_MAX_TYPES];
int types[TZ_MAX_TYPES];
int okay;
if (tmp->tm_isdst > 1)
tmp->tm_isdst = 1;
t = time2(tmp, funcp, offset, &okay, sp);
#define PCTS 1
#ifdef PCTS
/*
** PCTS code courtesy Grant Sullivan.
*/
if (okay)
return t;
if (tmp->tm_isdst < 0)
tmp->tm_isdst = 0; /* reset to std and try again */
#endif /* defined PCTS */
#ifndef PCTS
if (okay || tmp->tm_isdst < 0)
return t;
#endif /* !defined PCTS */
/*
** We're supposed to assume that somebody took a time of one type
** and did some math on it that yielded a "struct tm" that's bad.
** We try to divine the type they started from and adjust to the
** type they need.
*/
/*
** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
*/
#ifdef ALL_STATE
if (sp == NULL)
return WRONG;
#endif /* defined ALL_STATE */
for (i = 0; i < sp->typecnt; ++i)
seen[i] = FALSE;
nseen = 0;
for (i = sp->timecnt - 1; i >= 0; --i)
if (!seen[sp->types[i]]) {
seen[sp->types[i]] = TRUE;
types[nseen++] = sp->types[i];
}
for (sameind = 0; sameind < nseen; ++sameind) {
samei = types[sameind];
if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
continue;
for (otherind = 0; otherind < nseen; ++otherind) {
otheri = types[otherind];
if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
continue;
tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
t = time2(tmp, funcp, offset, &okay, sp);
if (okay)
return t;
tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
}
}
return WRONG;
}
// ============================================================================
time_t
mktime_tz(struct tm * const tmp, char const * tz)
{
struct state st;
if (tzload(tz, &st, TRUE) != 0) {
// not sure what's best here, but for now, we fall back to gmt
gmtload(&st);
}
return time1(tmp, localsub, 0L, &st);
}
Reference in a new issue View git blame Copy permalink