xref: /PHP-5.4/ext/date/lib/interval.c (revision c0d060f5)
1 /*
2    +----------------------------------------------------------------------+
3    | PHP Version 5                                                        |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1997-2014 The PHP Group                                |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 3.01 of the PHP license,      |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.php.net/license/3_01.txt                                  |
11    | If you did not receive a copy of the PHP license and are unable to   |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@php.net so we can mail you a copy immediately.               |
14    +----------------------------------------------------------------------+
15    | Authors: Derick Rethans <derick@derickrethans.nl>                    |
16    +----------------------------------------------------------------------+
17  */
18 
19 /* $Id$ */
20 
21 #include "timelib.h"
22 #include <math.h>
23 
timelib_diff(timelib_time * one,timelib_time * two)24 timelib_rel_time *timelib_diff(timelib_time *one, timelib_time *two)
25 {
26 	timelib_rel_time *rt;
27 	timelib_time *swp;
28 	timelib_sll dst_corr = 0 ,dst_h_corr = 0, dst_m_corr = 0;
29 	timelib_time one_backup, two_backup;
30 
31 	rt = timelib_rel_time_ctor();
32 	rt->invert = 0;
33 	if (one->sse > two->sse) {
34 		swp = two;
35 		two = one;
36 		one = swp;
37 		rt->invert = 1;
38 	}
39 
40 	/* Calculate correction for DST change over, but only if the TZ type is ID
41 	 * and it's the same */
42 	if (one->zone_type == 3 && two->zone_type == 3
43 		&& (strcmp(one->tz_info->name, two->tz_info->name) == 0)
44 		&& (one->z != two->z))
45 	{
46 		dst_corr = two->z - one->z;
47 		dst_h_corr = dst_corr / 3600;
48 		dst_m_corr = (dst_corr % 3600) / 60;
49 	}
50 
51 	/* Save old TZ info */
52 	memcpy(&one_backup, one, sizeof(one_backup));
53 	memcpy(&two_backup, two, sizeof(two_backup));
54 
55     timelib_apply_localtime(one, 0);
56     timelib_apply_localtime(two, 0);
57 
58 	rt->y = two->y - one->y;
59 	rt->m = two->m - one->m;
60 	rt->d = two->d - one->d;
61 	rt->h = two->h - one->h;
62 	rt->i = two->i - one->i;
63 	rt->s = two->s - one->s;
64 	if (one_backup.dst == 0 && two_backup.dst == 1 && two->sse >= one->sse + 86400 - dst_corr) {
65 		rt->h += dst_h_corr;
66 		rt->i += dst_m_corr;
67 	}
68 
69 	rt->days = abs(floor((one->sse - two->sse - (dst_h_corr * 3600) - (dst_m_corr * 60)) / 86400));
70 
71 	timelib_do_rel_normalize(rt->invert ? one : two, rt);
72 
73 	/* We need to do this after normalisation otherwise we can't get "24H" */
74 	if (one_backup.dst == 1 && two_backup.dst == 0 && two->sse >= one->sse + 86400) {
75 		if (two->sse < one->sse + 86400 - dst_corr) {
76 			rt->d--;
77 			rt->h = 24;
78 		} else {
79 			rt->h += dst_h_corr;
80 			rt->i += dst_m_corr;
81 		}
82 	}
83 
84 	/* Restore old TZ info */
85 	memcpy(one, &one_backup, sizeof(one_backup));
86 	memcpy(two, &two_backup, sizeof(two_backup));
87 
88 	return rt;
89 }
90 
timelib_add(timelib_time * old_time,timelib_rel_time * interval)91 timelib_time *timelib_add(timelib_time *old_time, timelib_rel_time *interval)
92 {
93 	int bias = 1;
94 	timelib_time *t = timelib_time_clone(old_time);
95 
96 	if (interval->have_weekday_relative || interval->have_special_relative) {
97 		memcpy(&t->relative, interval, sizeof(struct timelib_rel_time));
98 	} else {
99 		if (interval->invert) {
100 			bias = -1;
101 		}
102 		memset(&t->relative, 0, sizeof(struct timelib_rel_time));
103 		t->relative.y = interval->y * bias;
104 		t->relative.m = interval->m * bias;
105 		t->relative.d = interval->d * bias;
106 		t->relative.h = interval->h * bias;
107 		t->relative.i = interval->i * bias;
108 		t->relative.s = interval->s * bias;
109 	}
110 	t->have_relative = 1;
111 	t->sse_uptodate = 0;
112 
113 	timelib_update_ts(t, NULL);
114 
115 //	printf("%lld %lld %d\n", old_time->dst, t->dst, (t->sse - old_time->sse));
116 	/* Adjust for backwards DST changeover */
117 	if (old_time->dst == 1 && t->dst == 0 && !interval->y && !interval->m && !interval->d) {
118 		t->sse -= old_time->z;
119 		t->sse += t->z;
120 	}
121 
122 	timelib_update_from_sse(t);
123 	t->have_relative = 0;
124 
125 	return t;
126 }
127 
timelib_sub(timelib_time * old_time,timelib_rel_time * interval)128 timelib_time *timelib_sub(timelib_time *old_time, timelib_rel_time *interval)
129 {
130 	int bias = 1;
131 	timelib_time *t = timelib_time_clone(old_time);
132 
133 	if (interval->invert) {
134 		bias = -1;
135 	}
136 
137 	memset(&t->relative, 0, sizeof(struct timelib_rel_time));
138 	t->relative.y = 0 - (interval->y * bias);
139 	t->relative.m = 0 - (interval->m * bias);
140 	t->relative.d = 0 - (interval->d * bias);
141 	t->relative.h = 0 - (interval->h * bias);
142 	t->relative.i = 0 - (interval->i * bias);
143 	t->relative.s = 0 - (interval->s * bias);
144 	t->have_relative = 1;
145 	t->sse_uptodate = 0;
146 
147 	timelib_update_ts(t, NULL);
148 
149 	/* Adjust for backwards DST changeover */
150 	if (old_time->dst == 1 && t->dst == 0 && !interval->y && !interval->m && !interval->d) {
151 		t->sse -= old_time->z;
152 		t->sse += t->z;
153 	}
154 	/* Adjust for forwards DST changeover */
155 	if (old_time->dst == 0 && t->dst == 1 && !interval->y && !interval->m && !interval->d ) {
156 		t->sse -= old_time->z;
157 		t->sse += t->z;
158 	}
159 
160 	timelib_update_from_sse(t);
161 
162 	t->have_relative = 0;
163 
164 	return t;
165 }
166