1 /*
2 * The MIT License (MIT)
3 *
4 * Copyright (c) 2015 Derick Rethans
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "timelib.h"
26 #include "timelib_private.h"
27
28 /* jan feb mrt apr may jun jul aug sep oct nov dec */
29 static int month_tab_leap[12] = { -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
30 static int month_tab[12] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
31
32 /* dec jan feb mrt apr may jun jul aug sep oct nov dec */
33 static int days_in_month_leap[13] = { 31, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
34 static int days_in_month[13] = { 31, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
35
do_range_limit_fraction(timelib_sll * fraction,timelib_sll * seconds)36 static void do_range_limit_fraction(timelib_sll *fraction, timelib_sll *seconds)
37 {
38 if (*fraction < 0) {
39 *fraction += 1000000;
40 *seconds -= 1;
41 }
42 if (*fraction >= 1000000) {
43 *fraction -= 1000000;
44 *seconds += 1;
45 }
46 }
47
do_range_limit(timelib_sll start,timelib_sll end,timelib_sll adj,timelib_sll * a,timelib_sll * b)48 static void do_range_limit(timelib_sll start, timelib_sll end, timelib_sll adj, timelib_sll *a, timelib_sll *b)
49 {
50 if (*a < start) {
51 *b -= (start - *a - 1) / adj + 1;
52 *a += adj * ((start - *a - 1) / adj + 1);
53 }
54 if (*a >= end) {
55 *b += *a / adj;
56 *a -= adj * (*a / adj);
57 }
58 }
59
inc_month(timelib_sll * y,timelib_sll * m)60 static void inc_month(timelib_sll *y, timelib_sll *m)
61 {
62 (*m)++;
63 if (*m > 12) {
64 *m -= 12;
65 (*y)++;
66 }
67 }
68
dec_month(timelib_sll * y,timelib_sll * m)69 static void dec_month(timelib_sll *y, timelib_sll *m)
70 {
71 (*m)--;
72 if (*m < 1) {
73 *m += 12;
74 (*y)--;
75 }
76 }
77
do_range_limit_days_relative(timelib_sll * base_y,timelib_sll * base_m,timelib_sll * y,timelib_sll * m,timelib_sll * d,timelib_sll invert)78 static void do_range_limit_days_relative(timelib_sll *base_y, timelib_sll *base_m, timelib_sll *y, timelib_sll *m, timelib_sll *d, timelib_sll invert)
79 {
80 timelib_sll leapyear;
81 timelib_sll month, year;
82 timelib_sll days;
83
84 do_range_limit(1, 13, 12, base_m, base_y);
85
86 year = *base_y;
87 month = *base_m;
88
89 /*
90 printf( "S: Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days);
91 */
92 if (!invert) {
93 while (*d < 0) {
94 dec_month(&year, &month);
95 leapyear = timelib_is_leap(year);
96 days = leapyear ? days_in_month_leap[month] : days_in_month[month];
97
98 /* printf( "I Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days); */
99
100 *d += days;
101 (*m)--;
102 }
103 } else {
104 while (*d < 0) {
105 leapyear = timelib_is_leap(year);
106 days = leapyear ? days_in_month_leap[month] : days_in_month[month];
107
108 /* printf( "I Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days); */
109
110 *d += days;
111 (*m)--;
112 inc_month(&year, &month);
113 }
114 }
115 /*
116 printf( "E: Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days);
117 */
118 }
119
do_range_limit_days(timelib_sll * y,timelib_sll * m,timelib_sll * d)120 static int do_range_limit_days(timelib_sll *y, timelib_sll *m, timelib_sll *d)
121 {
122 timelib_sll leapyear;
123 timelib_sll days_this_month;
124 timelib_sll last_month, last_year;
125 timelib_sll days_last_month;
126
127 /* can jump an entire leap year period quickly */
128 if (*d >= DAYS_PER_LYEAR_PERIOD || *d <= -DAYS_PER_LYEAR_PERIOD) {
129 *y += YEARS_PER_LYEAR_PERIOD * (*d / DAYS_PER_LYEAR_PERIOD);
130 *d -= DAYS_PER_LYEAR_PERIOD * (*d / DAYS_PER_LYEAR_PERIOD);
131 }
132
133 do_range_limit(1, 13, 12, m, y);
134
135 leapyear = timelib_is_leap(*y);
136 days_this_month = leapyear ? days_in_month_leap[*m] : days_in_month[*m];
137 last_month = (*m) - 1;
138
139 if (last_month < 1) {
140 last_month += 12;
141 last_year = (*y) - 1;
142 } else {
143 last_year = (*y);
144 }
145 leapyear = timelib_is_leap(last_year);
146 days_last_month = leapyear ? days_in_month_leap[last_month] : days_in_month[last_month];
147
148 if (*d <= 0) {
149 *d += days_last_month;
150 (*m)--;
151 return 1;
152 }
153 if (*d > days_this_month) {
154 *d -= days_this_month;
155 (*m)++;
156 return 1;
157 }
158 return 0;
159 }
160
do_adjust_for_weekday(timelib_time * time)161 static void do_adjust_for_weekday(timelib_time* time)
162 {
163 timelib_sll current_dow, difference;
164
165 current_dow = timelib_day_of_week(time->y, time->m, time->d);
166 if (time->relative.weekday_behavior == 2)
167 {
168 /* To make "this week" work, where the current DOW is a "sunday" */
169 if (current_dow == 0 && time->relative.weekday != 0) {
170 time->relative.weekday -= 7;
171 }
172
173 /* To make "sunday this week" work, where the current DOW is not a
174 * "sunday" */
175 if (time->relative.weekday == 0 && current_dow != 0) {
176 time->relative.weekday = 7;
177 }
178
179 time->d -= current_dow;
180 time->d += time->relative.weekday;
181 return;
182 }
183 difference = time->relative.weekday - current_dow;
184 if ((time->relative.d < 0 && difference < 0) || (time->relative.d >= 0 && difference <= -time->relative.weekday_behavior)) {
185 difference += 7;
186 }
187 if (time->relative.weekday >= 0) {
188 time->d += difference;
189 } else {
190 time->d -= (7 - (abs(time->relative.weekday) - current_dow));
191 }
192 time->relative.have_weekday_relative = 0;
193 }
194
timelib_do_rel_normalize(timelib_time * base,timelib_rel_time * rt)195 void timelib_do_rel_normalize(timelib_time *base, timelib_rel_time *rt)
196 {
197 do_range_limit_fraction(&rt->us, &rt->s);
198 do_range_limit(0, 60, 60, &rt->s, &rt->i);
199 do_range_limit(0, 60, 60, &rt->i, &rt->h);
200 do_range_limit(0, 24, 24, &rt->h, &rt->d);
201 do_range_limit(0, 12, 12, &rt->m, &rt->y);
202
203 do_range_limit_days_relative(&base->y, &base->m, &rt->y, &rt->m, &rt->d, rt->invert);
204 do_range_limit(0, 12, 12, &rt->m, &rt->y);
205 }
206
207 #define EPOCH_DAY 719468
208
magic_date_calc(timelib_time * time)209 static void magic_date_calc(timelib_time *time)
210 {
211 timelib_sll y, ddd, mi, mm, dd, g;
212
213 /* The algorithm doesn't work before the year 1 */
214 if (time->d < -719498) {
215 return;
216 }
217
218 g = time->d + EPOCH_DAY - 1;
219
220 y = (10000 * g + 14780) / 3652425;
221 ddd = g - ((365*y) + (y/4) - (y/100) + (y/400));
222 if (ddd < 0) {
223 y--;
224 ddd = g - ((365*y) + (y/4) - (y/100) + (y/400));
225 }
226 mi = (100 * ddd + 52) / 3060;
227 mm = ((mi + 2) % 12) + 1;
228 y = y + (mi + 2) / 12;
229 dd = ddd - ((mi * 306 + 5) / 10) + 1;
230 time->y = y;
231 time->m = mm;
232 time->d = dd;
233 }
234
timelib_do_normalize(timelib_time * time)235 void timelib_do_normalize(timelib_time* time)
236 {
237 if (time->us != TIMELIB_UNSET) do_range_limit_fraction(&time->us, &time->s);
238 if (time->s != TIMELIB_UNSET) do_range_limit(0, 60, 60, &time->s, &time->i);
239 if (time->s != TIMELIB_UNSET) do_range_limit(0, 60, 60, &time->i, &time->h);
240 if (time->s != TIMELIB_UNSET) do_range_limit(0, 24, 24, &time->h, &time->d);
241 do_range_limit(1, 13, 12, &time->m, &time->y);
242
243 /* Short cut if we're doing things against the Epoch */
244 if (time->y == 1970 && time->m == 1 && time->d != 1) {
245 magic_date_calc(time);
246 }
247
248 do {} while (do_range_limit_days(&time->y, &time->m, &time->d));
249 do_range_limit(1, 13, 12, &time->m, &time->y);
250 }
251
do_adjust_relative(timelib_time * time)252 static void do_adjust_relative(timelib_time* time)
253 {
254 if (time->relative.have_weekday_relative) {
255 do_adjust_for_weekday(time);
256 }
257 timelib_do_normalize(time);
258
259 if (time->have_relative) {
260 time->us += time->relative.us;
261
262 time->s += time->relative.s;
263 time->i += time->relative.i;
264 time->h += time->relative.h;
265
266 time->d += time->relative.d;
267 time->m += time->relative.m;
268 time->y += time->relative.y;
269 }
270
271 switch (time->relative.first_last_day_of) {
272 case TIMELIB_SPECIAL_FIRST_DAY_OF_MONTH: /* first */
273 time->d = 1;
274 break;
275 case TIMELIB_SPECIAL_LAST_DAY_OF_MONTH: /* last */
276 time->d = 0;
277 time->m++;
278 break;
279 }
280
281 timelib_do_normalize(time);
282 }
283
do_adjust_special_weekday(timelib_time * time)284 static void do_adjust_special_weekday(timelib_time* time)
285 {
286 timelib_sll count, dow, rem;
287
288 count = time->relative.special.amount;
289 dow = timelib_day_of_week(time->y, time->m, time->d);
290
291 /* Add increments of 5 weekdays as a week, leaving the DOW unchanged. */
292 time->d += (count / 5) * 7;
293
294 /* Deal with the remainder. */
295 rem = (count % 5);
296
297 if (count > 0) {
298 if (rem == 0) {
299 /* Head back to Friday if we stop on the weekend. */
300 if (dow == 0) {
301 time->d -= 2;
302 } else if (dow == 6) {
303 time->d -= 1;
304 }
305 } else if (dow == 6) {
306 /* We ended up on Saturday, but there's still work to do, so move
307 * to Sunday and continue from there. */
308 time->d += 1;
309 } else if (dow + rem > 5) {
310 /* We're on a weekday, but we're going past Friday, so skip right
311 * over the weekend. */
312 time->d += 2;
313 }
314 } else {
315 /* Completely mirror the forward direction. This also covers the 0
316 * case, since if we start on the weekend, we want to move forward as
317 * if we stopped there while going backwards. */
318 if (rem == 0) {
319 if (dow == 6) {
320 time->d += 2;
321 } else if (dow == 0) {
322 time->d += 1;
323 }
324 } else if (dow == 0) {
325 time->d -= 1;
326 } else if (dow + rem < 1) {
327 time->d -= 2;
328 }
329 }
330
331 time->d += rem;
332 }
333
do_adjust_special(timelib_time * time)334 static void do_adjust_special(timelib_time* time)
335 {
336 if (time->relative.have_special_relative) {
337 switch (time->relative.special.type) {
338 case TIMELIB_SPECIAL_WEEKDAY:
339 do_adjust_special_weekday(time);
340 break;
341 }
342 }
343 timelib_do_normalize(time);
344 memset(&(time->relative.special), 0, sizeof(time->relative.special));
345 }
346
do_adjust_special_early(timelib_time * time)347 static void do_adjust_special_early(timelib_time* time)
348 {
349 if (time->relative.have_special_relative) {
350 switch (time->relative.special.type) {
351 case TIMELIB_SPECIAL_DAY_OF_WEEK_IN_MONTH:
352 time->d = 1;
353 time->m += time->relative.m;
354 time->relative.m = 0;
355 break;
356 case TIMELIB_SPECIAL_LAST_DAY_OF_WEEK_IN_MONTH:
357 time->d = 1;
358 time->m += time->relative.m + 1;
359 time->relative.m = 0;
360 break;
361 }
362 }
363 switch (time->relative.first_last_day_of) {
364 case TIMELIB_SPECIAL_FIRST_DAY_OF_MONTH: /* first */
365 time->d = 1;
366 break;
367 case TIMELIB_SPECIAL_LAST_DAY_OF_MONTH: /* last */
368 time->d = 0;
369 time->m++;
370 break;
371 }
372 timelib_do_normalize(time);
373 }
374
do_years(timelib_sll year)375 static timelib_sll do_years(timelib_sll year)
376 {
377 timelib_sll i;
378 timelib_sll res = 0;
379 timelib_sll eras;
380
381 eras = (year - 1970) / 40000;
382 if (eras != 0) {
383 year = year - (eras * 40000);
384 res += (SECS_PER_ERA * eras * 100);
385 }
386
387 if (year >= 1970) {
388 for (i = year - 1; i >= 1970; i--) {
389 if (timelib_is_leap(i)) {
390 res += (DAYS_PER_LYEAR * SECS_PER_DAY);
391 } else {
392 res += (DAYS_PER_YEAR * SECS_PER_DAY);
393 }
394 }
395 } else {
396 for (i = 1969; i >= year; i--) {
397 if (timelib_is_leap(i)) {
398 res -= (DAYS_PER_LYEAR * SECS_PER_DAY);
399 } else {
400 res -= (DAYS_PER_YEAR * SECS_PER_DAY);
401 }
402 }
403 }
404 return res;
405 }
406
do_months(timelib_ull month,timelib_sll year)407 static timelib_sll do_months(timelib_ull month, timelib_sll year)
408 {
409 if (timelib_is_leap(year)) {
410 return ((month_tab_leap[month - 1] + 1) * SECS_PER_DAY);
411 } else {
412 return ((month_tab[month - 1]) * SECS_PER_DAY);
413 }
414 }
415
do_days(timelib_ull day)416 static timelib_sll do_days(timelib_ull day)
417 {
418 return ((day - 1) * SECS_PER_DAY);
419 }
420
do_time(timelib_ull hour,timelib_ull minute,timelib_ull second)421 static timelib_sll do_time(timelib_ull hour, timelib_ull minute, timelib_ull second)
422 {
423 timelib_sll res = 0;
424
425 res += hour * 3600;
426 res += minute * 60;
427 res += second;
428 return res;
429 }
430
do_adjust_timezone(timelib_time * tz,timelib_tzinfo * tzi)431 static timelib_sll do_adjust_timezone(timelib_time *tz, timelib_tzinfo *tzi)
432 {
433 switch (tz->zone_type) {
434 case TIMELIB_ZONETYPE_OFFSET:
435
436 tz->is_localtime = 1;
437 return -tz->z;
438 break;
439
440 case TIMELIB_ZONETYPE_ABBR: {
441 timelib_sll tmp;
442
443 tz->is_localtime = 1;
444 tmp = -tz->z;
445 tmp -= tz->dst * 3600;
446 return tmp;
447 }
448 break;
449
450 case TIMELIB_ZONETYPE_ID:
451 tzi = tz->tz_info;
452 /* Break intentionally missing */
453
454 default:
455 /* No timezone in struct, fallback to reference if possible */
456 if (tzi) {
457 timelib_time_offset *before, *after;
458 timelib_sll tmp;
459 int in_transition;
460
461 tz->is_localtime = 1;
462 before = timelib_get_time_zone_info(tz->sse, tzi);
463 after = timelib_get_time_zone_info(tz->sse - before->offset, tzi);
464 timelib_set_timezone(tz, tzi);
465
466 in_transition = (
467 ((tz->sse - after->offset) >= (after->transition_time + (before->offset - after->offset))) &&
468 ((tz->sse - after->offset) < after->transition_time)
469 );
470
471 if ((before->offset != after->offset) && !in_transition) {
472 tmp = -after->offset;
473 } else {
474 tmp = -tz->z;
475 }
476 timelib_time_offset_dtor(before);
477 timelib_time_offset_dtor(after);
478
479 {
480 timelib_time_offset *gmt_offset;
481
482 gmt_offset = timelib_get_time_zone_info(tz->sse + tmp, tzi);
483 tz->z = gmt_offset->offset;
484
485 tz->dst = gmt_offset->is_dst;
486 if (tz->tz_abbr) {
487 timelib_free(tz->tz_abbr);
488 }
489 tz->tz_abbr = timelib_strdup(gmt_offset->abbr);
490 timelib_time_offset_dtor(gmt_offset);
491 }
492 return tmp;
493 }
494 }
495 return 0;
496 }
497
timelib_update_ts(timelib_time * time,timelib_tzinfo * tzi)498 void timelib_update_ts(timelib_time* time, timelib_tzinfo* tzi)
499 {
500 timelib_sll res = 0;
501
502 do_adjust_special_early(time);
503 do_adjust_relative(time);
504 do_adjust_special(time);
505 res += do_years(time->y);
506 res += do_months(time->m, time->y);
507 res += do_days(time->d);
508 res += do_time(time->h, time->i, time->s);
509 time->sse = res;
510
511 res += do_adjust_timezone(time, tzi);
512 time->sse = res;
513
514 time->sse_uptodate = 1;
515 time->have_relative = time->relative.have_weekday_relative = time->relative.have_special_relative = time->relative.first_last_day_of = 0;
516 }
517
518 #if 0
519 int main(void)
520 {
521 timelib_sll res;
522 timelib_time time;
523
524 time = timelib_strtotime("10 Feb 2005 06:07:03 PM CET"); /* 1108055223 */
525 printf ("%04d-%02d-%02d %02d:%02d:%02d.%-5d %+04d %1d",
526 time.y, time.m, time.d, time.h, time.i, time.s, time.f, time.z, time.dst);
527 if (time.have_relative) {
528 printf ("%3dY %3dM %3dD / %3dH %3dM %3dS",
529 time.relative.y, time.relative.m, time.relative.d, time.relative.h, time.relative.i, time.relative.s);
530 }
531 if (time.have_weekday_relative) {
532 printf (" / %d", time.relative.weekday);
533 }
534 res = time2unixtime(&time);
535 printf("%Ld\n", res);
536
537 return 0;
538 }
539 #endif
540
