libc: new date apis

The current date and time APIs on Plan 9 are not good. They're
inflexible, non-threadsafe, and don't expose timezone information.

This commit adds new time APIs that allow parsing arbitrary
dates, work from multiple threads, and can handle timezones
effectively.

1 files changed, 3 insertions, 194 deletions

diff --git a/sys/src/libc/9sys/tm2sec.c b/sys/src/libc/9sys/tm2sec.c
index 20bebd0c8..8b3a9d967 100644
--- a/sys/src/libc/9sys/tm2sec.c
+++ b/sys/src/libc/9sys/tm2sec.c
@@ -1,202 +1,11 @@
 #include <u.h>
 #include <libc.h>
 
-#define	TZSIZE	150
-static	void	readtimezone(void);
-static	int	rd_name(char**, char*);
-static	int	rd_long(char**, long*);
-static
-struct
-{
-	char	stname[4];
-	char	dlname[4];
-	long	stdiff;
-	long	dldiff;
-	long	dlpairs[TZSIZE];
-} timezone;
-
-#define SEC2MIN 60L
-#define SEC2HOUR (60L*SEC2MIN)
-#define SEC2DAY (24L*SEC2HOUR)
-
-/*
- *  days per month plus days/year
- */
-static	int	dmsize[] =
-{
-	365, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
-};
-static	int	ldmsize[] =
-{
-	366, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
-};
-
-/*
- *  return the days/month for the given year
- */
-static int *
-yrsize(int y)
-{
-	if((y%4) == 0 && ((y%100) != 0 || (y%400) == 0))
-		return ldmsize;
-	else
-		return dmsize;
-}
-
-/*
- * compute seconds since Jan 1 1970 GMT
- * and convert to our timezone.
- */
 long
 tm2sec(Tm *tm)
 {
-	long secs, *p;
-	int i, yday, year, *d2m;
-
-	if(strcmp(tm->zone, "GMT") != 0 && timezone.stname[0] == 0)
-		readtimezone();
-	secs = 0;
-
-	/*
-	 *  seconds per year
-	 */
-	year = tm->year + 1900;
-	for(i = 1970; i < year; i++){
-		d2m = yrsize(i);
-		secs += d2m[0] * SEC2DAY;
-	}
-
-	/*
-	 *  if mday is set, use mon and mday to compute yday
-	 */
-	if(tm->mday){
-		yday = 0;
-		d2m = yrsize(year);
-		for(i=0; i<tm->mon; i++)
-			yday += d2m[i+1];
-		yday += tm->mday-1;
-	}else{
-		yday = tm->yday;
-	}
-	secs += yday * SEC2DAY;
-
-	/*
-	 * hours, minutes, seconds
-	 */
-	secs += tm->hour * SEC2HOUR;
-	secs += tm->min * SEC2MIN;
-	secs += tm->sec;
-
-	/*
-	 * Only handles zones mentioned in /env/timezone,
-	 * but things get too ambiguous otherwise.
-	 */
-	if(strcmp(tm->zone, timezone.stname) == 0)
-		secs -= timezone.stdiff;
-	else if(strcmp(tm->zone, timezone.dlname) == 0)
-		secs -= timezone.dldiff;
-	else if(tm->zone[0] == 0){
-		secs -= timezone.dldiff;
-		for(p = timezone.dlpairs; *p; p += 2)
-			if(secs >= p[0] && secs < p[1])
-				break;
-		if(*p == 0){
-			secs += timezone.dldiff;
-			secs -= timezone.stdiff;
-		}
-	}
-	return secs;
-}
-
-static
-void
-readtimezone(void)
-{
-	char buf[TZSIZE*11+30], *p;
-	int i;
-
-	memset(buf, 0, sizeof(buf));
-	i = open("/env/timezone", 0);
-	if(i < 0)
-		goto error;
-	if(read(i, buf, sizeof(buf)) >= sizeof(buf))
-		goto error;
-	close(i);
-	p = buf;
-	if(rd_name(&p, timezone.stname))
-		goto error;
-	if(rd_long(&p, &timezone.stdiff))
-		goto error;
-	if(rd_name(&p, timezone.dlname))
-		goto error;
-	if(rd_long(&p, &timezone.dldiff))
-		goto error;
-	for(i=0; i<TZSIZE; i++) {
-		if(rd_long(&p, &timezone.dlpairs[i]))
-			goto error;
-		if(timezone.dlpairs[i] == 0)
-			return;
-	}
-
-error:
-	timezone.stdiff = 0;
-	strcpy(timezone.stname, "GMT");
-	timezone.dlpairs[0] = 0;
-}
-
-static int
-rd_name(char **f, char *p)
-{
-	int c, i;
-
-	for(;;) {
-		c = *(*f)++;
-		if(c != ' ' && c != '\n')
-			break;
-	}
-	for(i=0; i<3; i++) {
-		if(c == ' ' || c == '\n')
-			return 1;
-		*p++ = c;
-		c = *(*f)++;
-	}
-	if(c != ' ' && c != '\n')
-		return 1;
-	*p = 0;
-	return 0;
-}
-
-static int
-rd_long(char **f, long *p)
-{
-	int c, s;
-	long l;
+	Tm tt;
 
-	s = 0;
-	for(;;) {
-		c = *(*f)++;
-		if(c == '-') {
-			s++;
-			continue;
-		}
-		if(c != ' ' && c != '\n')
-			break;
-	}
-	if(c == 0) {
-		*p = 0;
-		return 0;
-	}
-	l = 0;
-	for(;;) {
-		if(c == ' ' || c == '\n')
-			break;
-		if(c < '0' || c > '9')
-			return 1;
-		l = l*10 + c-'0';
-		c = *(*f)++;
-	}
-	if(s)
-		l = -l;
-	*p = l;
-	return 0;
+	tt = *tm;
+	return tmnorm(&tt);
 }