xref: /freebsd/lib/libc/stdtime/time32.c (revision 783d3ff6d7fae619db8a7990b8a6387de0c677b5)
1 /*-
2  * Copyright (c) 2001 FreeBSD Inc.
3  * All rights reserved.
4  *
5  * These routines are for converting time_t to fixed-bit representations
6  * for use in protocols or storage.  When converting time to a larger
7  * representation of time_t these routines are expected to assume temporal
8  * locality and use the 50-year rule to properly set the msb bits.  XXX
9  *
10  * Redistribution and use under the terms of the COPYRIGHT file at the
11  * base of the source tree.
12  */
13 
14 #include <sys/types.h>
15 #include <timeconv.h>
16 
17 /*
18  * Convert a 32 bit representation of time_t into time_t.  XXX needs to
19  * implement the 50-year rule to handle post-2038 conversions.
20  */
21 time_t
22 _time32_to_time(__int32_t t32)
23 {
24     return((time_t)t32);
25 }
26 
27 /*
28  * Convert time_t to a 32 bit representation.  If time_t is 64 bits we can
29  * simply chop it down.   The resulting 32 bit representation can be
30  * converted back to a temporally local 64 bit time_t using time32_to_time.
31  */
32 __int32_t
33 _time_to_time32(time_t t)
34 {
35     return((__int32_t)t);
36 }
37 
38 /*
39  * Convert a 64 bit representation of time_t into time_t.  If time_t is
40  * represented as 32 bits we can simply chop it and not support times
41  * past 2038.
42  */
43 time_t
44 _time64_to_time(__int64_t t64)
45 {
46     return((time_t)t64);
47 }
48 
49 /*
50  * Convert time_t to a 64 bit representation.  If time_t is represented
51  * as 32 bits we simply sign-extend and do not support times past 2038.
52  */
53 __int64_t
54 _time_to_time64(time_t t)
55 {
56     return((__int64_t)t);
57 }
58 
59 /*
60  * Convert to/from 'long'.  Depending on the sizeof(long) this may or
61  * may not require using the 50-year rule.
62  */
63 long
64 _time_to_long(time_t t)
65 {
66     if (sizeof(long) == sizeof(__int64_t))
67 	return(_time_to_time64(t));
68     return((long)t);
69 }
70 
71 time_t
72 _long_to_time(long tlong)
73 {
74     if (sizeof(long) == sizeof(__int32_t))
75 	return(_time32_to_time(tlong));
76     return((time_t)tlong);
77 }
78 
79 /*
80  * Convert to/from 'int'.  Depending on the sizeof(int) this may or
81  * may not require using the 50-year rule.
82  */
83 int
84 _time_to_int(time_t t)
85 {
86     if (sizeof(int) == sizeof(__int64_t))
87 	return(_time_to_time64(t));
88     return((int)t);
89 }
90 
91 time_t
92 _int_to_time(int tint)
93 {
94     if (sizeof(int) == sizeof(__int32_t))
95 	return(_time32_to_time(tint));
96     return((time_t)tint);
97 }
98