/src/php-src/ext/date/lib/interval.c

Source
/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2015-2019 Derick Rethans
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "timelib.h"
#include "timelib_private.h"
#include <math.h>

static void swap_times(timelib_time **one, timelib_time **two, timelib_rel_time *rt)
{
  timelib_time *swp;

  swp = *two;
  *two = *one;
  *one = swp;
  rt->invert = 1;
}

static void sort_old_to_new(timelib_time **one, timelib_time **two, timelib_rel_time *rt)
{
  /* Check whether date/times need to be inverted. If both times are
   * TIMELIB_ZONETYPE_ID times with the same TZID, we use the y-s + us fields. */
  if (
    (*one)->zone_type == TIMELIB_ZONETYPE_ID &&
    (*two)->zone_type == TIMELIB_ZONETYPE_ID &&
    (strcmp((*one)->tz_info->name, (*two)->tz_info->name) == 0)
  ) {
    if (
      ((*one)->y > (*two)->y) ||
      ((*one)->y == (*two)->y && (*one)->m > (*two)->m) ||
      ((*one)->y == (*two)->y && (*one)->m == (*two)->m && (*one)->d > (*two)->d) ||
      ((*one)->y == (*two)->y && (*one)->m == (*two)->m && (*one)->d == (*two)->d && (*one)->h > (*two)->h) ||
      ((*one)->y == (*two)->y && (*one)->m == (*two)->m && (*one)->d == (*two)->d && (*one)->h == (*two)->h && (*one)->i > (*two)->i) ||
      ((*one)->y == (*two)->y && (*one)->m == (*two)->m && (*one)->d == (*two)->d && (*one)->h == (*two)->h && (*one)->i == (*two)->i && (*one)->s > (*two)->s) ||
      ((*one)->y == (*two)->y && (*one)->m == (*two)->m && (*one)->d == (*two)->d && (*one)->h == (*two)->h && (*one)->i == (*two)->i && (*one)->s == (*two)->s && (*one)->us > (*two)->us)
    ) {
      swap_times(one, two, rt);
    }
    return;
  }

  /* Fall back to using the SSE instead to rearrange */
  if (
    ((*one)->sse > (*two)->sse) ||
    ((*one)->sse == (*two)->sse && (*one)->us > (*two)->us)
  ) {
    swap_times(one, two, rt);
  }
}

static timelib_rel_time *timelib_diff_with_tzid(timelib_time *one, timelib_time *two)
{
  timelib_rel_time *rt;
  timelib_sll       dst_corr = 0, dst_h_corr = 0, dst_m_corr = 0;
  int32_t           trans_offset;
  timelib_sll       trans_transition_time;

  rt = timelib_rel_time_ctor();
  rt->invert = 0;

  sort_old_to_new(&one, &two, rt);

  /* Calculate correction for UTC offset changes between first and second SSE */
  dst_corr = two->z - one->z;
  dst_h_corr = dst_corr / 3600;
  dst_m_corr = (dst_corr % 3600) / 60;

  rt->y = two->y - one->y;
  rt->m = two->m - one->m;
  rt->d = two->d - one->d;
  rt->h = two->h - one->h;
  rt->i = two->i - one->i;
  rt->s = two->s - one->s;
  rt->us = two->us - one->us;

  rt->days = timelib_diff_days(one, two);

  /* Fall Back: Cater for transition period, where rt->invert is 0, but there are negative numbers */
  if (two->sse < one->sse) {
    timelib_sll flipped = llabs((rt->i * 60) + (rt->s) - dst_corr);
    rt->h = flipped / SECS_PER_HOUR;
    rt->i = (flipped - rt->h * SECS_PER_HOUR) / 60;
    rt->s = flipped % 60;

    rt->invert = 1 - rt->invert;
  }

  timelib_do_rel_normalize(rt->invert ? one : two, rt);

  if (one->dst == 1 && two->dst == 0) { /* Fall Back */
    if (two->tz_info) {
      if ((two->sse - one->sse + dst_corr) < SECS_PER_DAY) {
        rt->h -= dst_h_corr;
        rt->i -= dst_m_corr;
      }
    }
  } else if (one->dst == 0 && two->dst == 1) { /* Spring Forward */
    if (two->tz_info) {
      int success = timelib_get_time_zone_offset_info(two->sse, two->tz_info, &trans_offset, &trans_transition_time, NULL);

      if (
        success &&
        !((one->sse + SECS_PER_DAY > trans_transition_time) && (one->sse + SECS_PER_DAY <= (trans_transition_time + dst_corr))) &&
        two->sse >= trans_transition_time &&
        ((two->sse - one->sse + dst_corr) % SECS_PER_DAY) > (two->sse - trans_transition_time)
      ) {
        rt->h -= dst_h_corr;
        rt->i -= dst_m_corr;
      }
    }
  } else if (two->sse - one->sse >= SECS_PER_DAY) {
    /* Check whether we're in the period to the next transition time */
    if (timelib_get_time_zone_offset_info(two->sse - two->z, two->tz_info, &trans_offset, &trans_transition_time, NULL)) {
      dst_corr = one->z - trans_offset;

      if (two->sse >= trans_transition_time - dst_corr && two->sse < trans_transition_time) {
        rt->d--;
        rt->h = 24;
      }
    }
  }

  return rt;
}

timelib_rel_time *timelib_diff(timelib_time *one, timelib_time *two)
{
  timelib_rel_time *rt;

  if (one->zone_type == TIMELIB_ZONETYPE_ID && two->zone_type == TIMELIB_ZONETYPE_ID && strcmp(one->tz_info->name, two->tz_info->name) == 0) {
    return timelib_diff_with_tzid(one, two);
  }

  rt = timelib_rel_time_ctor();
  rt->invert = 0;

  sort_old_to_new(&one, &two, rt);

  rt->y = two->y - one->y;
  rt->m = two->m - one->m;
  rt->d = two->d - one->d;
  rt->h = two->h - one->h;
  if (one->zone_type != TIMELIB_ZONETYPE_ID) {
    rt->h = rt->h + one->dst;
  }
  if (two->zone_type != TIMELIB_ZONETYPE_ID) {
    rt->h = rt->h - two->dst;
  }
  rt->i = two->i - one->i;
  rt->s = two->s - one->s - two->z + one->z;
  rt->us = two->us - one->us;

  rt->days = timelib_diff_days(one, two);

  timelib_do_rel_normalize(rt->invert ? one : two, rt);

  return rt;
}


int timelib_diff_days(timelib_time *one, timelib_time *two)
{
  int days = 0;

  if (timelib_same_timezone(one, two)) {
    timelib_time *earliest, *latest;
    double earliest_time, latest_time;

    if (timelib_time_compare(one, two) < 0) {
      earliest = one;
      latest = two;
    } else {
      earliest = two;
      latest = one;
    }
    timelib_hmsf_to_decimal_hour(earliest->h, earliest->i, earliest->s, earliest->us, &earliest_time);
    timelib_hmsf_to_decimal_hour(latest->h, latest->i, latest->s, latest->us, &latest_time);

    days = llabs(timelib_epoch_days_from_time(one) - timelib_epoch_days_from_time(two));
    if (latest_time < earliest_time && days > 0) {
      days--;
    }
  } else {
    /* FIXME: This truncates the range of days to INT_MAX to avoid an
     * overflow later on. Ideally, all APIs have better error handling. */
    double ddays = fabs(floor(one->sse - two->sse) / 86400);
    days = ddays <= INT_MAX ? ddays : INT_MAX;
  }

  return days;
}


timelib_time *timelib_add(timelib_time *old_time, timelib_rel_time *interval)
{
  int bias = 1;
  timelib_time *t = timelib_time_clone(old_time);

  if (interval->have_weekday_relative || interval->have_special_relative) {
    memcpy(&t->relative, interval, sizeof(timelib_rel_time));
  } else {
    if (interval->invert) {
      bias = -1;
    }
    memset(&t->relative, 0, sizeof(timelib_rel_time));
    t->relative.y = interval->y * bias;
    t->relative.m = interval->m * bias;
    t->relative.d = interval->d * bias;
    t->relative.h = interval->h * bias;
    t->relative.i = interval->i * bias;
    t->relative.s = interval->s * bias;
    t->relative.us = interval->us * bias;
  }
  t->have_relative = 1;
  t->sse_uptodate = 0;

  timelib_update_ts(t, NULL);

  timelib_update_from_sse(t);
  t->have_relative = 0;

  return t;
}

timelib_time *timelib_sub(timelib_time *old_time, timelib_rel_time *interval)
{
  int bias = 1;
  timelib_time *t = timelib_time_clone(old_time);

  if (interval->invert) {
    bias = -1;
  }

  memset(&t->relative, 0, sizeof(timelib_rel_time));
  t->relative.y = 0 - (interval->y * bias);
  t->relative.m = 0 - (interval->m * bias);
  t->relative.d = 0 - (interval->d * bias);
  t->relative.h = 0 - (interval->h * bias);
  t->relative.i = 0 - (interval->i * bias);
  t->relative.s = 0 - (interval->s * bias);
  t->relative.us = 0 - (interval->us * bias);
  t->have_relative = 1;
  t->sse_uptodate = 0;

  timelib_update_ts(t, NULL);

  timelib_update_from_sse(t);

  t->have_relative = 0;

  return t;
}

static void do_range_limit(timelib_sll start, timelib_sll end, timelib_sll adj, timelib_sll *a, timelib_sll *b)
{
  if (*a < start) {
    *b -= (start - *a - 1) / adj + 1;
    *a += adj * ((start - *a - 1) / adj + 1);
  }
  if (*a >= end) {
    *b += *a / adj;
    *a -= adj * (*a / adj);
  }
}


timelib_time *timelib_add_wall(timelib_time *old_time, timelib_rel_time *interval)
{
  int bias = 1;
  timelib_time *t = timelib_time_clone(old_time);

  t->have_relative = 1;
  t->sse_uptodate = 0;

  if (interval->have_weekday_relative || interval->have_special_relative) {
    memcpy(&t->relative, interval, sizeof(timelib_rel_time));

    timelib_update_ts(t, NULL);

    timelib_update_from_sse(t);
  } else {
    if (interval->invert) {
      bias = -1;
    }
    memset(&t->relative, 0, sizeof(timelib_rel_time));
    t->relative.y = interval->y * bias;
    t->relative.m = interval->m * bias;
    t->relative.d = interval->d * bias;

    if (t->relative.y || t->relative.m || t->relative.d) {
      timelib_update_ts(t, NULL);
    }

    if (interval->us == 0) {
      t->sse += bias * timelib_hms_to_seconds(interval->h, interval->i, interval->s);
      timelib_update_from_sse(t);
    } else {
      timelib_rel_time *temp_interval = timelib_rel_time_clone(interval);

      do_range_limit(0, 1000000, 1000000, &temp_interval->us, &temp_interval->s);
      t->sse += bias * timelib_hms_to_seconds(temp_interval->h, temp_interval->i, temp_interval->s);
      timelib_update_from_sse(t);
      t->us += temp_interval->us * bias;

      timelib_do_normalize(t);
      timelib_update_ts(t, NULL);

      timelib_rel_time_dtor(temp_interval);
    }
    timelib_do_normalize(t);
  }

  if (t->zone_type == TIMELIB_ZONETYPE_ID) {
    timelib_set_timezone(t, t->tz_info);
  }
  t->have_relative = 0;

  return t;
}

timelib_time *timelib_sub_wall(timelib_time *old_time, timelib_rel_time *interval)
{
  int bias = 1;
  timelib_time *t = timelib_time_clone(old_time);

  t->have_relative = 1;
  t->sse_uptodate = 0;

  if (interval->have_weekday_relative || interval->have_special_relative) {
    memcpy(&t->relative, interval, sizeof(timelib_rel_time));

    timelib_update_ts(t, NULL);
    timelib_update_from_sse(t);
  } else {
    if (interval->invert) {
      bias = -1;
    }
    memset(&t->relative, 0, sizeof(timelib_rel_time));
    t->relative.y = 0 - (interval->y * bias);
    t->relative.m = 0 - (interval->m * bias);
    t->relative.d = 0 - (interval->d * bias);

    if (t->relative.y || t->relative.m || t->relative.d) {
      timelib_update_ts(t, NULL);
    }

    if (interval->us == 0) {
      t->sse -= bias * timelib_hms_to_seconds(interval->h, interval->i, interval->s);
      timelib_update_from_sse(t);
    } else {
      timelib_rel_time *temp_interval = timelib_rel_time_clone(interval);

      do_range_limit(0, 1000000, 1000000, &temp_interval->us, &temp_interval->s);
      t->sse -= bias * timelib_hms_to_seconds(temp_interval->h, temp_interval->i, temp_interval->s);
      timelib_update_from_sse(t);
      t->us -= temp_interval->us * bias;

      timelib_do_normalize(t);
      timelib_update_ts(t, NULL);

      timelib_rel_time_dtor(temp_interval);
    }
    timelib_do_normalize(t);
  }

  if (t->zone_type == TIMELIB_ZONETYPE_ID) {
    timelib_set_timezone(t, t->tz_info);
  }
  t->have_relative = 0;

  return t;
}

Coverage Report

Created: 2026-09-14 06:25

Line	Count	Source
1		/*
2		* The MIT License (MIT)
3		*
4		* Copyright (c) 2015-2019 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		#include <math.h>
28
29		static void swap_times(timelib_time one, timelib_time two, timelib_rel_time *rt)
30	0	{
31	0	timelib_time *swp;
32
33	0	swp = *two;
34	0	two = one;
35	0	*one = swp;
36	0	rt->invert = 1;
37	0	}
38
39		static void sort_old_to_new(timelib_time one, timelib_time two, timelib_rel_time *rt)
40	10	{
41		/* Check whether date/times need to be inverted. If both times are
42		* TIMELIB_ZONETYPE_ID times with the same TZID, we use the y-s + us fields. */
43	10	if (
44	10	(*one)->zone_type == TIMELIB_ZONETYPE_ID &&
45	10	(*two)->zone_type == TIMELIB_ZONETYPE_ID &&
46	10	(strcmp((one)->tz_info->name, (two)->tz_info->name) == 0)
47	10	) {
48	10	if (
49	10	((one)->y > (two)->y) \|\|
50	10	((one)->y == (two)->y && (one)->m > (two)->m) \|\|
51	10	((one)->y == (two)->y && (one)->m == (two)->m && (one)->d > (two)->d) \|\|
52	10	((one)->y == (two)->y && (one)->m == (two)->m && (one)->d == (two)->d && (one)->h > (two)->h) \|\|
53	10	((one)->y == (two)->y && (one)->m == (two)->m && (one)->d == (two)->d && (one)->h == (two)->h && (one)->i > (two)->i) \|\|
54	10	((one)->y == (two)->y && (one)->m == (two)->m && (one)->d == (two)->d && (one)->h == (two)->h && (one)->i == (two)->i && (one)->s > (two)->s) \|\|
55	10	((one)->y == (two)->y && (one)->m == (two)->m && (one)->d == (two)->d && (one)->h == (two)->h && (one)->i == (two)->i && (one)->s == (two)->s && (one)->us > (two)->us)
56	10	) {
57	0	swap_times(one, two, rt);
58	0	}
59	10	return;
60	10	}
61
62		/* Fall back to using the SSE instead to rearrange */
63	0	if (
64	0	((one)->sse > (two)->sse) \|\|
65	0	((one)->sse == (two)->sse && (one)->us > (two)->us)
66	0	) {
67	0	swap_times(one, two, rt);
68	0	}
69	0	}
70
71		static timelib_rel_time timelib_diff_with_tzid(timelib_time one, timelib_time *two)
72	10	{
73	10	timelib_rel_time *rt;
74	10	timelib_sll dst_corr = 0, dst_h_corr = 0, dst_m_corr = 0;
75	10	int32_t trans_offset;
76	10	timelib_sll trans_transition_time;
77
78	10	rt = timelib_rel_time_ctor();
79	10	rt->invert = 0;
80
81	10	sort_old_to_new(&one, &two, rt);
82
83		/* Calculate correction for UTC offset changes between first and second SSE */
84	10	dst_corr = two->z - one->z;
85	10	dst_h_corr = dst_corr / 3600;
86	10	dst_m_corr = (dst_corr % 3600) / 60;
87
88	10	rt->y = two->y - one->y;
89	10	rt->m = two->m - one->m;
90	10	rt->d = two->d - one->d;
91	10	rt->h = two->h - one->h;
92	10	rt->i = two->i - one->i;
93	10	rt->s = two->s - one->s;
94	10	rt->us = two->us - one->us;
95
96	10	rt->days = timelib_diff_days(one, two);
97
98		/* Fall Back: Cater for transition period, where rt->invert is 0, but there are negative numbers */
99	10	if (two->sse < one->sse) {
100	0	timelib_sll flipped = llabs((rt->i * 60) + (rt->s) - dst_corr);
101	0	rt->h = flipped / SECS_PER_HOUR;
102	0	rt->i = (flipped - rt->h * SECS_PER_HOUR) / 60;
103	0	rt->s = flipped % 60;
104
105	0	rt->invert = 1 - rt->invert;
106	0	}
107
108	10	timelib_do_rel_normalize(rt->invert ? one : two, rt);
109
110	10	if (one->dst == 1 && two->dst == 0) { /* Fall Back */
111	0	if (two->tz_info) {
112	0	if ((two->sse - one->sse + dst_corr) < SECS_PER_DAY) {
113	0	rt->h -= dst_h_corr;
114	0	rt->i -= dst_m_corr;
115	0	}
116	0	}
117	10	} else if (one->dst == 0 && two->dst == 1) { /* Spring Forward */
118	0	if (two->tz_info) {
119	0	int success = timelib_get_time_zone_offset_info(two->sse, two->tz_info, &trans_offset, &trans_transition_time, NULL);
120
121	0	if (
122	0	success &&
123	0	!((one->sse + SECS_PER_DAY > trans_transition_time) && (one->sse + SECS_PER_DAY <= (trans_transition_time + dst_corr))) &&
124	0	two->sse >= trans_transition_time &&
125	0	((two->sse - one->sse + dst_corr) % SECS_PER_DAY) > (two->sse - trans_transition_time)
126	0	) {
127	0	rt->h -= dst_h_corr;
128	0	rt->i -= dst_m_corr;
129	0	}
130	0	}
131	10	} else if (two->sse - one->sse >= SECS_PER_DAY) {
132		/* Check whether we're in the period to the next transition time */
133	0	if (timelib_get_time_zone_offset_info(two->sse - two->z, two->tz_info, &trans_offset, &trans_transition_time, NULL)) {
134	0	dst_corr = one->z - trans_offset;
135
136	0	if (two->sse >= trans_transition_time - dst_corr && two->sse < trans_transition_time) {
137	0	rt->d--;
138	0	rt->h = 24;
139	0	}
140	0	}
141	0	}
142
143	10	return rt;
144	10	}
145
146		timelib_rel_time timelib_diff(timelib_time one, timelib_time *two)
147	10	{
148	10	timelib_rel_time *rt;
149
150	10	if (one->zone_type == TIMELIB_ZONETYPE_ID && two->zone_type == TIMELIB_ZONETYPE_ID && strcmp(one->tz_info->name, two->tz_info->name) == 0) {
151	10	return timelib_diff_with_tzid(one, two);
152	10	}
153
154	0	rt = timelib_rel_time_ctor();
155	0	rt->invert = 0;
156
157	0	sort_old_to_new(&one, &two, rt);
158
159	0	rt->y = two->y - one->y;
160	0	rt->m = two->m - one->m;
161	0	rt->d = two->d - one->d;
162	0	rt->h = two->h - one->h;
163	0	if (one->zone_type != TIMELIB_ZONETYPE_ID) {
164	0	rt->h = rt->h + one->dst;
165	0	}
166	0	if (two->zone_type != TIMELIB_ZONETYPE_ID) {
167	0	rt->h = rt->h - two->dst;
168	0	}
169	0	rt->i = two->i - one->i;
170	0	rt->s = two->s - one->s - two->z + one->z;
171	0	rt->us = two->us - one->us;
172
173	0	rt->days = timelib_diff_days(one, two);
174
175	0	timelib_do_rel_normalize(rt->invert ? one : two, rt);
176
177	0	return rt;
178	10	}
179
180
181		int timelib_diff_days(timelib_time one, timelib_time two)
182	10	{
183	10	int days = 0;
184
185	10	if (timelib_same_timezone(one, two)) {
186	10	timelib_time earliest, latest;
187	10	double earliest_time, latest_time;
188
189	10	if (timelib_time_compare(one, two) < 0) {
190	10	earliest = one;
191	10	latest = two;
192	10	} else {
193	0	earliest = two;
194	0	latest = one;
195	0	}
196	10	timelib_hmsf_to_decimal_hour(earliest->h, earliest->i, earliest->s, earliest->us, &earliest_time);
197	10	timelib_hmsf_to_decimal_hour(latest->h, latest->i, latest->s, latest->us, &latest_time);
198
199	10	days = llabs(timelib_epoch_days_from_time(one) - timelib_epoch_days_from_time(two));
200	10	if (latest_time < earliest_time && days > 0) {
201	0	days--;
202	0	}
203	10	} else {
204		/* FIXME: This truncates the range of days to INT_MAX to avoid an
205		* overflow later on. Ideally, all APIs have better error handling. */
206	0	double ddays = fabs(floor(one->sse - two->sse) / 86400);
207	0	days = ddays <= INT_MAX ? ddays : INT_MAX;
208	0	}
209
210	10	return days;
211	10	}
212
213
214		timelib_time timelib_add(timelib_time old_time, timelib_rel_time *interval)
215	0	{
216	0	int bias = 1;
217	0	timelib_time *t = timelib_time_clone(old_time);
218
219	0	if (interval->have_weekday_relative \|\| interval->have_special_relative) {
220	0	memcpy(&t->relative, interval, sizeof(timelib_rel_time));
221	0	} else {
222	0	if (interval->invert) {
223	0	bias = -1;
224	0	}
225	0	memset(&t->relative, 0, sizeof(timelib_rel_time));
226	0	t->relative.y = interval->y * bias;
227	0	t->relative.m = interval->m * bias;
228	0	t->relative.d = interval->d * bias;
229	0	t->relative.h = interval->h * bias;
230	0	t->relative.i = interval->i * bias;
231	0	t->relative.s = interval->s * bias;
232	0	t->relative.us = interval->us * bias;
233	0	}
234	0	t->have_relative = 1;
235	0	t->sse_uptodate = 0;
236
237	0	timelib_update_ts(t, NULL);
238
239	0	timelib_update_from_sse(t);
240	0	t->have_relative = 0;
241
242	0	return t;
243	0	}
244
245		timelib_time timelib_sub(timelib_time old_time, timelib_rel_time *interval)
246	0	{
247	0	int bias = 1;
248	0	timelib_time *t = timelib_time_clone(old_time);
249
250	0	if (interval->invert) {
251	0	bias = -1;
252	0	}
253
254	0	memset(&t->relative, 0, sizeof(timelib_rel_time));
255	0	t->relative.y = 0 - (interval->y * bias);
256	0	t->relative.m = 0 - (interval->m * bias);
257	0	t->relative.d = 0 - (interval->d * bias);
258	0	t->relative.h = 0 - (interval->h * bias);
259	0	t->relative.i = 0 - (interval->i * bias);
260	0	t->relative.s = 0 - (interval->s * bias);
261	0	t->relative.us = 0 - (interval->us * bias);
262	0	t->have_relative = 1;
263	0	t->sse_uptodate = 0;
264
265	0	timelib_update_ts(t, NULL);
266
267	0	timelib_update_from_sse(t);
268
269	0	t->have_relative = 0;
270
271	0	return t;
272	0	}
273
274		static void do_range_limit(timelib_sll start, timelib_sll end, timelib_sll adj, timelib_sll a, timelib_sll b)
275	0	{
276	0	if (*a < start) {
277	0	b -= (start - a - 1) / adj + 1;
278	0	a += adj ((start - *a - 1) / adj + 1);
279	0	}
280	0	if (*a >= end) {
281	0	b += a / adj;
282	0	a -= adj (*a / adj);
283	0	}
284	0	}
285
286
287		timelib_time timelib_add_wall(timelib_time old_time, timelib_rel_time *interval)
288	0	{
289	0	int bias = 1;
290	0	timelib_time *t = timelib_time_clone(old_time);
291
292	0	t->have_relative = 1;
293	0	t->sse_uptodate = 0;
294
295	0	if (interval->have_weekday_relative \|\| interval->have_special_relative) {
296	0	memcpy(&t->relative, interval, sizeof(timelib_rel_time));
297
298	0	timelib_update_ts(t, NULL);
299
300	0	timelib_update_from_sse(t);
301	0	} else {
302	0	if (interval->invert) {
303	0	bias = -1;
304	0	}
305	0	memset(&t->relative, 0, sizeof(timelib_rel_time));
306	0	t->relative.y = interval->y * bias;
307	0	t->relative.m = interval->m * bias;
308	0	t->relative.d = interval->d * bias;
309
310	0	if (t->relative.y \|\| t->relative.m \|\| t->relative.d) {
311	0	timelib_update_ts(t, NULL);
312	0	}
313
314	0	if (interval->us == 0) {
315	0	t->sse += bias * timelib_hms_to_seconds(interval->h, interval->i, interval->s);
316	0	timelib_update_from_sse(t);
317	0	} else {
318	0	timelib_rel_time *temp_interval = timelib_rel_time_clone(interval);
319
320	0	do_range_limit(0, 1000000, 1000000, &temp_interval->us, &temp_interval->s);
321	0	t->sse += bias * timelib_hms_to_seconds(temp_interval->h, temp_interval->i, temp_interval->s);
322	0	timelib_update_from_sse(t);
323	0	t->us += temp_interval->us * bias;
324
325	0	timelib_do_normalize(t);
326	0	timelib_update_ts(t, NULL);
327
328	0	timelib_rel_time_dtor(temp_interval);
329	0	}
330	0	timelib_do_normalize(t);
331	0	}
332
333	0	if (t->zone_type == TIMELIB_ZONETYPE_ID) {
334	0	timelib_set_timezone(t, t->tz_info);
335	0	}
336	0	t->have_relative = 0;
337
338	0	return t;
339	0	}
340
341		timelib_time timelib_sub_wall(timelib_time old_time, timelib_rel_time *interval)
342	0	{
343	0	int bias = 1;
344	0	timelib_time *t = timelib_time_clone(old_time);
345
346	0	t->have_relative = 1;
347	0	t->sse_uptodate = 0;
348
349	0	if (interval->have_weekday_relative \|\| interval->have_special_relative) {
350	0	memcpy(&t->relative, interval, sizeof(timelib_rel_time));
351
352	0	timelib_update_ts(t, NULL);
353	0	timelib_update_from_sse(t);
354	0	} else {
355	0	if (interval->invert) {
356	0	bias = -1;
357	0	}
358	0	memset(&t->relative, 0, sizeof(timelib_rel_time));
359	0	t->relative.y = 0 - (interval->y * bias);
360	0	t->relative.m = 0 - (interval->m * bias);
361	0	t->relative.d = 0 - (interval->d * bias);
362
363	0	if (t->relative.y \|\| t->relative.m \|\| t->relative.d) {
364	0	timelib_update_ts(t, NULL);
365	0	}
366
367	0	if (interval->us == 0) {
368	0	t->sse -= bias * timelib_hms_to_seconds(interval->h, interval->i, interval->s);
369	0	timelib_update_from_sse(t);
370	0	} else {
371	0	timelib_rel_time *temp_interval = timelib_rel_time_clone(interval);
372
373	0	do_range_limit(0, 1000000, 1000000, &temp_interval->us, &temp_interval->s);
374	0	t->sse -= bias * timelib_hms_to_seconds(temp_interval->h, temp_interval->i, temp_interval->s);
375	0	timelib_update_from_sse(t);
376	0	t->us -= temp_interval->us * bias;
377
378	0	timelib_do_normalize(t);
379	0	timelib_update_ts(t, NULL);
380
381	0	timelib_rel_time_dtor(temp_interval);
382	0	}
383	0	timelib_do_normalize(t);
384	0	}
385
386	0	if (t->zone_type == TIMELIB_ZONETYPE_ID) {
387	0	timelib_set_timezone(t, t->tz_info);
388	0	}
389	0	t->have_relative = 0;
390
391	0	return t;
392	0	}