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private.h
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1 #ifndef PRIVATE_H
2 #define PRIVATE_H
3 
4 /*
5  * This file is in the public domain, so clarified as of
6  * 1996-06-05 by Arthur David Olson.
7  *
8  * IDENTIFICATION
9  * src/timezone/private.h
10  */
11 
12 /*
13  * This header is for use ONLY with the time conversion code.
14  * There is no guarantee that it will remain unchanged,
15  * or that it will remain at all.
16  * Do NOT copy it to any system include directory.
17  * Thank you!
18  */
19 
20 #include <limits.h> /* for CHAR_BIT et al. */
21 #include <sys/wait.h> /* for WIFEXITED and WEXITSTATUS */
22 #include <unistd.h> /* for F_OK and R_OK */
23 
24 #include "pgtime.h"
25 
26 /* This string was in the Factory zone through version 2016f. */
27 #define GRANDPARENTED "Local time zone must be set--see zic manual page"
28 
29 /*
30  * IANA has a bunch of HAVE_FOO #defines here, but in PG we want pretty
31  * much all of that to be done by PG's configure script.
32  */
33 
34 #ifndef ENOTSUP
35 #define ENOTSUP EINVAL
36 #endif
37 #ifndef EOVERFLOW
38 #define EOVERFLOW EINVAL
39 #endif
40 
41 /* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
42 #define is_digit(c) ((unsigned)(c) - '0' <= 9)
43 
44 
45 /*
46  * Finally, some convenience items.
47  */
48 
49 #define TYPE_BIT(type) (sizeof (type) * CHAR_BIT)
50 #define TYPE_SIGNED(type) (((type) -1) < 0)
51 #define TWOS_COMPLEMENT(t) ((t) ~ (t) 0 < 0)
52 
53 /*
54  * Max and min values of the integer type T, of which only the bottom
55  * B bits are used, and where the highest-order used bit is considered
56  * to be a sign bit if T is signed.
57  */
58 #define MAXVAL(t, b) \
59  ((t) (((t) 1 << ((b) - 1 - TYPE_SIGNED(t))) \
60  - 1 + ((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))))
61 #define MINVAL(t, b) \
62  ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
63 
64 /* The extreme time values, assuming no padding. */
65 #define TIME_T_MIN MINVAL(pg_time_t, TYPE_BIT(pg_time_t))
66 #define TIME_T_MAX MAXVAL(pg_time_t, TYPE_BIT(pg_time_t))
67 
68 /*
69  * 302 / 1000 is log10(2.0) rounded up.
70  * Subtract one for the sign bit if the type is signed;
71  * add one for integer division truncation;
72  * add one more for a minus sign if the type is signed.
73  */
74 #define INT_STRLEN_MAXIMUM(type) \
75  ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
76  1 + TYPE_SIGNED(type))
77 
78 /*
79  * INITIALIZE(x)
80  */
81 #define INITIALIZE(x) ((x) = 0)
82 
83 #undef _
84 #define _(msgid) (msgid)
85 
86 /* Handy macros that are independent of tzfile implementation. */
87 
88 #define YEARSPERREPEAT 400 /* years before a Gregorian repeat */
89 
90 #define SECSPERMIN 60
91 #define MINSPERHOUR 60
92 #define HOURSPERDAY 24
93 #define DAYSPERWEEK 7
94 #define DAYSPERNYEAR 365
95 #define DAYSPERLYEAR 366
96 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
97 #define SECSPERDAY ((int32) SECSPERHOUR * HOURSPERDAY)
98 #define MONSPERYEAR 12
99 
100 #define TM_SUNDAY 0
101 #define TM_MONDAY 1
102 #define TM_TUESDAY 2
103 #define TM_WEDNESDAY 3
104 #define TM_THURSDAY 4
105 #define TM_FRIDAY 5
106 #define TM_SATURDAY 6
107 
108 #define TM_JANUARY 0
109 #define TM_FEBRUARY 1
110 #define TM_MARCH 2
111 #define TM_APRIL 3
112 #define TM_MAY 4
113 #define TM_JUNE 5
114 #define TM_JULY 6
115 #define TM_AUGUST 7
116 #define TM_SEPTEMBER 8
117 #define TM_OCTOBER 9
118 #define TM_NOVEMBER 10
119 #define TM_DECEMBER 11
120 
121 #define TM_YEAR_BASE 1900
122 
123 #define EPOCH_YEAR 1970
124 #define EPOCH_WDAY TM_THURSDAY
125 
126 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
127 
128 /*
129  * Since everything in isleap is modulo 400 (or a factor of 400), we know that
130  * isleap(y) == isleap(y % 400)
131  * and so
132  * isleap(a + b) == isleap((a + b) % 400)
133  * or
134  * isleap(a + b) == isleap(a % 400 + b % 400)
135  * This is true even if % means modulo rather than Fortran remainder
136  * (which is allowed by C89 but not by C99 or later).
137  * We use this to avoid addition overflow problems.
138  */
139 
140 #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
141 
142 
143 /*
144  * The Gregorian year averages 365.2425 days, which is 31556952 seconds.
145  */
146 
147 #define AVGSECSPERYEAR 31556952L
148 #define SECSPERREPEAT \
149  ((int64) YEARSPERREPEAT * (int64) AVGSECSPERYEAR)
150 #define SECSPERREPEAT_BITS 34 /* ceil(log2(SECSPERREPEAT)) */
151 
152 #endif /* !defined PRIVATE_H */