1 #include <u.h>
2 #include <libc.h>
3 
4 #include "zoneinfo.h"
5 
6 #define SEC2MIN 60L
7 #define SEC2HOUR (60L*SEC2MIN)
8 #define SEC2DAY (24L*SEC2HOUR)
9 
10 /*
11  *  days per month plus days/year
12  */
13 static	int	dmsize[] =
14 {
15 	365, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
16 };
17 static	int	ldmsize[] =
18 {
19 	366, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
20 };
21 
22 /*
23  *  return the days/month for the given year
24  */
25 static int *
26 yrsize(int y)
27 {
28 	if((y%4) == 0 && ((y%100) != 0 || (y%400) == 0))
29 		return ldmsize;
30 	else
31 		return dmsize;
32 }
33 
34 /*
35  * compute seconds since Jan 1 1970 GMT
36  * and convert to our timezone.
37  */
38 long
39 tm2sec(Tm *tm)
40 {
41 	Tinfo ti0, ti1, *ti;
42 	long secs;
43 	int i, yday, year, *d2m;
44 
45 	secs = 0;
46 
47 	/*
48 	 *  seconds per year
49 	 */
50 	year = tm->year + 1900;
51 	for(i = 1970; i < year; i++){
52 		d2m = yrsize(i);
53 		secs += d2m[0] * SEC2DAY;
54 	}
55 
56 	/*
57 	 *  if mday is set, use mon and mday to compute yday
58 	 */
59 	if(tm->mday){
60 		yday = 0;
61 		d2m = yrsize(year);
62 		for(i=0; i<tm->mon; i++)
63 			yday += d2m[i+1];
64 		yday += tm->mday-1;
65 	}else{
66 		yday = tm->yday;
67 	}
68 	secs += yday * SEC2DAY;
69 
70 	/*
71 	 * hours, minutes, seconds
72 	 */
73 	secs += tm->hour * SEC2HOUR;
74 	secs += tm->min * SEC2MIN;
75 	secs += tm->sec;
76 
77 	/*
78 	 * Assume the local time zone if zone is not GMT
79 	 */
80 	if(strcmp(tm->zone, "GMT") != 0) {
81 		i = zonelookuptinfo(&ti0, secs);
82 		ti = &ti0;
83 		if (i != -1)
84 		if (ti->tzoff!=0) {
85 			/*
86 			 * to what local time period `secs' belongs?
87 			 */
88 			if (ti->tzoff>0) {
89 				/*
90 				 * east of GMT; check previous local time transition
91 				 */
92 				if (ti->t+ti->tzoff > secs)
93 				if (zonetinfo(&ti1, i-1)!=-1)
94 					ti = &ti1;
95 			} else
96 				/*
97 				 * west of GMT; check next local time transition
98 				 */
99 				if (zonetinfo(&ti1, i+1))
100 				if (ti1.t+ti->tzoff < secs)
101 					ti = &ti1;
102 //			fprint(2, "tt: %ld+%d %ld\n", (long)ti->t, ti->tzoff, (long)secs);
103 			secs -= ti->tzoff;
104 		}
105 	}
106 
107 	if(secs < 0)
108 		secs = 0;
109 	return secs;
110 }