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
27 /* jan feb mrt apr may jun jul aug sep oct nov dec */
28 static int month_tab_leap[12] = { -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
29 static int month_tab[12] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
30
31 /* dec jan feb mrt apr may jun jul aug sep oct nov dec */
32 static int days_in_month_leap[13] = { 31, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
33 static int days_in_month[13] = { 31, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
34
do_range_limit(timelib_sll start,timelib_sll end,timelib_sll adj,timelib_sll * a,timelib_sll * b)35 static void do_range_limit(timelib_sll start, timelib_sll end, timelib_sll adj, timelib_sll *a, timelib_sll *b)
36 {
37 if (*a < start) {
38 *b -= (start - *a - 1) / adj + 1;
39 *a += adj * ((start - *a - 1) / adj + 1);
40 }
41 if (*a >= end) {
42 *b += *a / adj;
43 *a -= adj * (*a / adj);
44 }
45 }
46
inc_month(timelib_sll * y,timelib_sll * m)47 static void inc_month(timelib_sll *y, timelib_sll *m)
48 {
49 (*m)++;
50 if (*m > 12) {
51 *m -= 12;
52 (*y)++;
53 }
54 }
55
dec_month(timelib_sll * y,timelib_sll * m)56 static void dec_month(timelib_sll *y, timelib_sll *m)
57 {
58 (*m)--;
59 if (*m < 1) {
60 *m += 12;
61 (*y)--;
62 }
63 }
64
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)65 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)
66 {
67 timelib_sll leapyear;
68 timelib_sll month, year;
69 timelib_sll days;
70
71 do_range_limit(1, 13, 12, base_m, base_y);
72
73 year = *base_y;
74 month = *base_m;
75
76 /*
77 printf( "S: Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days);
78 */
79 if (!invert) {
80 while (*d < 0) {
81 dec_month(&year, &month);
82 leapyear = timelib_is_leap(year);
83 days = leapyear ? days_in_month_leap[month] : days_in_month[month];
84
85 /* printf( "I Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days); */
86
87 *d += days;
88 (*m)--;
89 }
90 } else {
91 while (*d < 0) {
92 leapyear = timelib_is_leap(year);
93 days = leapyear ? days_in_month_leap[month] : days_in_month[month];
94
95 /* printf( "I Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days); */
96
97 *d += days;
98 (*m)--;
99 inc_month(&year, &month);
100 }
101 }
102 /*
103 printf( "E: Y%d M%d %d %d %d %d\n", year, month, *y, *m, *d, days);
104 */
105 }
106
do_range_limit_days(timelib_sll * y,timelib_sll * m,timelib_sll * d)107 static int do_range_limit_days(timelib_sll *y, timelib_sll *m, timelib_sll *d)
108 {
109 timelib_sll leapyear;
110 timelib_sll days_this_month;
111 timelib_sll last_month, last_year;
112 timelib_sll days_last_month;
113
114 /* can jump an entire leap year period quickly */
115 if (*d >= DAYS_PER_LYEAR_PERIOD || *d <= -DAYS_PER_LYEAR_PERIOD) {
116 *y += YEARS_PER_LYEAR_PERIOD * (*d / DAYS_PER_LYEAR_PERIOD);
117 *d -= DAYS_PER_LYEAR_PERIOD * (*d / DAYS_PER_LYEAR_PERIOD);
118 }
119
120 do_range_limit(1, 13, 12, m, y);
121
122 leapyear = timelib_is_leap(*y);
123 days_this_month = leapyear ? days_in_month_leap[*m] : days_in_month[*m];
124 last_month = (*m) - 1;
125
126 if (last_month < 1) {
127 last_month += 12;
128 last_year = (*y) - 1;
129 } else {
130 last_year = (*y);
131 }
132 leapyear = timelib_is_leap(last_year);
133 days_last_month = leapyear ? days_in_month_leap[last_month] : days_in_month[last_month];
134
135 if (*d <= 0) {
136 *d += days_last_month;
137 (*m)--;
138 return 1;
139 }
140 if (*d > days_this_month) {
141 *d -= days_this_month;
142 (*m)++;
143 return 1;
144 }
145 return 0;
146 }
147
do_adjust_for_weekday(timelib_time * time)148 static void do_adjust_for_weekday(timelib_time* time)
149 {
150 timelib_sll current_dow, difference;
151
152 current_dow = timelib_day_of_week(time->y, time->m, time->d);
153 if (time->relative.weekday_behavior == 2)
154 {
155 if (time->relative.weekday == 0) {
156 time->relative.weekday = 7;
157 }
158 time->d -= current_dow;
159 time->d += time->relative.weekday;
160 return;
161 }
162 difference = time->relative.weekday - current_dow;
163 if ((time->relative.d < 0 && difference < 0) || (time->relative.d >= 0 && difference <= -time->relative.weekday_behavior)) {
164 difference += 7;
165 }
166 if (time->relative.weekday >= 0) {
167 time->d += difference;
168 } else {
169 time->d -= (7 - (abs(time->relative.weekday) - current_dow));
170 }
171 time->relative.have_weekday_relative = 0;
172 }
173
timelib_do_rel_normalize(timelib_time * base,timelib_rel_time * rt)174 void timelib_do_rel_normalize(timelib_time *base, timelib_rel_time *rt)
175 {
176 do_range_limit(0, 60, 60, &rt->s, &rt->i);
177 do_range_limit(0, 60, 60, &rt->i, &rt->h);
178 do_range_limit(0, 24, 24, &rt->h, &rt->d);
179 do_range_limit(0, 12, 12, &rt->m, &rt->y);
180
181 do_range_limit_days_relative(&base->y, &base->m, &rt->y, &rt->m, &rt->d, rt->invert);
182 do_range_limit(0, 12, 12, &rt->m, &rt->y);
183 }
184
timelib_do_normalize(timelib_time * time)185 void timelib_do_normalize(timelib_time* time)
186 {
187 if (time->s != TIMELIB_UNSET) do_range_limit(0, 60, 60, &time->s, &time->i);
188 if (time->s != TIMELIB_UNSET) do_range_limit(0, 60, 60, &time->i, &time->h);
189 if (time->s != TIMELIB_UNSET) do_range_limit(0, 24, 24, &time->h, &time->d);
190 do_range_limit(1, 13, 12, &time->m, &time->y);
191
192 do {} while (do_range_limit_days(&time->y, &time->m, &time->d));
193 do_range_limit(1, 13, 12, &time->m, &time->y);
194 }
195
do_adjust_relative(timelib_time * time)196 static void do_adjust_relative(timelib_time* time)
197 {
198 if (time->relative.have_weekday_relative) {
199 do_adjust_for_weekday(time);
200 }
201 timelib_do_normalize(time);
202
203 if (time->have_relative) {
204 time->s += time->relative.s;
205 time->i += time->relative.i;
206 time->h += time->relative.h;
207
208 time->d += time->relative.d;
209 time->m += time->relative.m;
210 time->y += time->relative.y;
211 }
212
213 switch (time->relative.first_last_day_of) {
214 case TIMELIB_SPECIAL_FIRST_DAY_OF_MONTH: /* first */
215 time->d = 1;
216 break;
217 case TIMELIB_SPECIAL_LAST_DAY_OF_MONTH: /* last */
218 time->d = 0;
219 time->m++;
220 break;
221 }
222
223 timelib_do_normalize(time);
224 }
225
do_adjust_special_weekday(timelib_time * time)226 static void do_adjust_special_weekday(timelib_time* time)
227 {
228 timelib_sll count, dow, rem;
229
230 count = time->relative.special.amount;
231 dow = timelib_day_of_week(time->y, time->m, time->d);
232
233 /* Add increments of 5 weekdays as a week, leaving the DOW unchanged. */
234 time->d += (count / 5) * 7;
235
236 /* Deal with the remainder. */
237 rem = (count % 5);
238
239 if (count > 0) {
240 if (rem == 0) {
241 /* Head back to Friday if we stop on the weekend. */
242 if (dow == 0) {
243 time->d -= 2;
244 } else if (dow == 6) {
245 time->d -= 1;
246 }
247 } else if (dow == 6) {
248 /* We ended up on Saturday, but there's still work to do, so move
249 * to Sunday and continue from there. */
250 time->d += 1;
251 } else if (dow + rem > 5) {
252 /* We're on a weekday, but we're going past Friday, so skip right
253 * over the weekend. */
254 time->d += 2;
255 }
256 } else {
257 /* Completely mirror the forward direction. This also covers the 0
258 * case, since if we start on the weekend, we want to move forward as
259 * if we stopped there while going backwards. */
260 if (rem == 0) {
261 if (dow == 6) {
262 time->d += 2;
263 } else if (dow == 0) {
264 time->d += 1;
265 }
266 } else if (dow == 0) {
267 time->d -= 1;
268 } else if (dow + rem < 1) {
269 time->d -= 2;
270 }
271 }
272
273 time->d += rem;
274 }
275
do_adjust_special(timelib_time * time)276 static void do_adjust_special(timelib_time* time)
277 {
278 if (time->relative.have_special_relative) {
279 switch (time->relative.special.type) {
280 case TIMELIB_SPECIAL_WEEKDAY:
281 do_adjust_special_weekday(time);
282 break;
283 }
284 }
285 timelib_do_normalize(time);
286 memset(&(time->relative.special), 0, sizeof(time->relative.special));
287 }
288
do_adjust_special_early(timelib_time * time)289 static void do_adjust_special_early(timelib_time* time)
290 {
291 if (time->relative.have_special_relative) {
292 switch (time->relative.special.type) {
293 case TIMELIB_SPECIAL_DAY_OF_WEEK_IN_MONTH:
294 time->d = 1;
295 time->m += time->relative.m;
296 time->relative.m = 0;
297 break;
298 case TIMELIB_SPECIAL_LAST_DAY_OF_WEEK_IN_MONTH:
299 time->d = 1;
300 time->m += time->relative.m + 1;
301 time->relative.m = 0;
302 break;
303 }
304 }
305 switch (time->relative.first_last_day_of) {
306 case TIMELIB_SPECIAL_FIRST_DAY_OF_MONTH: /* first */
307 time->d = 1;
308 break;
309 case TIMELIB_SPECIAL_LAST_DAY_OF_MONTH: /* last */
310 time->d = 0;
311 time->m++;
312 break;
313 }
314 timelib_do_normalize(time);
315 }
316
do_years(timelib_sll year)317 static timelib_sll do_years(timelib_sll year)
318 {
319 timelib_sll i;
320 timelib_sll res = 0;
321 timelib_sll eras;
322
323 eras = (year - 1970) / 40000;
324 if (eras != 0) {
325 year = year - (eras * 40000);
326 res += (SECS_PER_ERA * eras * 100);
327 }
328
329 if (year >= 1970) {
330 for (i = year - 1; i >= 1970; i--) {
331 if (timelib_is_leap(i)) {
332 res += (DAYS_PER_LYEAR * SECS_PER_DAY);
333 } else {
334 res += (DAYS_PER_YEAR * SECS_PER_DAY);
335 }
336 }
337 } else {
338 for (i = 1969; i >= year; i--) {
339 if (timelib_is_leap(i)) {
340 res -= (DAYS_PER_LYEAR * SECS_PER_DAY);
341 } else {
342 res -= (DAYS_PER_YEAR * SECS_PER_DAY);
343 }
344 }
345 }
346 return res;
347 }
348
do_months(timelib_ull month,timelib_ull year)349 static timelib_sll do_months(timelib_ull month, timelib_ull year)
350 {
351 if (timelib_is_leap(year)) {
352 return ((month_tab_leap[month - 1] + 1) * SECS_PER_DAY);
353 } else {
354 return ((month_tab[month - 1]) * SECS_PER_DAY);
355 }
356 }
357
do_days(timelib_ull day)358 static timelib_sll do_days(timelib_ull day)
359 {
360 return ((day - 1) * SECS_PER_DAY);
361 }
362
do_time(timelib_ull hour,timelib_ull minute,timelib_ull second)363 static timelib_sll do_time(timelib_ull hour, timelib_ull minute, timelib_ull second)
364 {
365 timelib_sll res = 0;
366
367 res += hour * 3600;
368 res += minute * 60;
369 res += second;
370 return res;
371 }
372
do_adjust_timezone(timelib_time * tz,timelib_tzinfo * tzi)373 static timelib_sll do_adjust_timezone(timelib_time *tz, timelib_tzinfo *tzi)
374 {
375 switch (tz->zone_type) {
376 case TIMELIB_ZONETYPE_OFFSET:
377
378 tz->is_localtime = 1;
379 return tz->z * 60;
380 break;
381
382 case TIMELIB_ZONETYPE_ABBR: {
383 timelib_sll tmp;
384
385 tz->is_localtime = 1;
386 tmp = tz->z;
387 tmp -= tz->dst * 60;
388 tmp *= 60;
389 return tmp;
390 }
391 break;
392
393 case TIMELIB_ZONETYPE_ID:
394 tzi = tz->tz_info;
395 /* Break intentionally missing */
396
397 default:
398 /* No timezone in struct, fallback to reference if possible */
399 if (tzi) {
400 timelib_time_offset *before, *after;
401 timelib_sll tmp;
402 int in_transistion;
403
404 tz->is_localtime = 1;
405 before = timelib_get_time_zone_info(tz->sse, tzi);
406 after = timelib_get_time_zone_info(tz->sse - before->offset, tzi);
407 timelib_set_timezone(tz, tzi);
408
409 in_transistion = (
410 ((tz->sse - after->offset) >= (after->transistion_time + (before->offset - after->offset))) &&
411 ((tz->sse - after->offset) < after->transistion_time)
412 );
413
414 if ((before->offset != after->offset) && !in_transistion) {
415 tmp = -after->offset;
416 } else {
417 tmp = -tz->z;
418 }
419 timelib_time_offset_dtor(before);
420 timelib_time_offset_dtor(after);
421
422 {
423 timelib_time_offset *gmt_offset;
424
425 gmt_offset = timelib_get_time_zone_info(tz->sse + tmp, tzi);
426 tz->z = gmt_offset->offset;
427
428 tz->dst = gmt_offset->is_dst;
429 if (tz->tz_abbr) {
430 timelib_free(tz->tz_abbr);
431 }
432 tz->tz_abbr = timelib_strdup(gmt_offset->abbr);
433 timelib_time_offset_dtor(gmt_offset);
434 }
435 return tmp;
436 }
437 }
438 return 0;
439 }
440
timelib_update_ts(timelib_time * time,timelib_tzinfo * tzi)441 void timelib_update_ts(timelib_time* time, timelib_tzinfo* tzi)
442 {
443 timelib_sll res = 0;
444
445 do_adjust_special_early(time);
446 do_adjust_relative(time);
447 do_adjust_special(time);
448 res += do_years(time->y);
449 res += do_months(time->m, time->y);
450 res += do_days(time->d);
451 res += do_time(time->h, time->i, time->s);
452 time->sse = res;
453
454 res += do_adjust_timezone(time, tzi);
455 time->sse = res;
456
457 time->sse_uptodate = 1;
458 time->have_relative = time->relative.have_weekday_relative = time->relative.have_special_relative = 0;
459 }
460
461 #if 0
462 int main(void)
463 {
464 timelib_sll res;
465 timelib_time time;
466
467 time = timelib_strtotime("10 Feb 2005 06:07:03 PM CET"); /* 1108055223 */
468 printf ("%04d-%02d-%02d %02d:%02d:%02d.%-5d %+04d %1d",
469 time.y, time.m, time.d, time.h, time.i, time.s, time.f, time.z, time.dst);
470 if (time.have_relative) {
471 printf ("%3dY %3dM %3dD / %3dH %3dM %3dS",
472 time.relative.y, time.relative.m, time.relative.d, time.relative.h, time.relative.i, time.relative.s);
473 }
474 if (time.have_weekday_relative) {
475 printf (" / %d", time.relative.weekday);
476 }
477 res = time2unixtime(&time);
478 printf("%Ld\n", res);
479
480 return 0;
481 }
482 #endif
483