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author | dillon <dillon@FreeBSD.org> | 2001-10-28 19:54:49 +0000 |
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committer | dillon <dillon@FreeBSD.org> | 2001-10-28 19:54:49 +0000 |
commit | 5b521f3c4f8da9d35e865fb9daa7a51e4fa00adb (patch) | |
tree | 4543d34cc7f31cf4431e62f7bbedbaf0179e4947 /lib | |
parent | ff38fb0e7374ef63944abf0515667857eaa6d61d (diff) | |
download | FreeBSD-src-5b521f3c4f8da9d35e865fb9daa7a51e4fa00adb.zip FreeBSD-src-5b521f3c4f8da9d35e865fb9daa7a51e4fa00adb.tar.gz |
Add routines to convert time_t to/from fixed-bit fields. These routines
serve two purposes: (1) so we can maintain backwards compatibility with
protocols (rwhod, dump, etc...) that either assume time_t is 32 bits or
assume sizeof(time_t) == sizeof(int), or make other similar assumptions.
(2) To tag such routines (by the presence of these calls) for future
cleanup/extension work.
The 32->64 routine, time32_to_time() (when time_t is 64 bits, that is),
is defined specifically to implement temporal locality to properly set the
msb bits of a 64 bit time_t quantity, using the 50 year rule. The locality
code has not been implemented yet (and doesn't need to be for a while),
but that is the intent. This will allow us to maintain backwards protocol
compatibility past 2038.
These routines are intended to be platform and time_t agnostic.
MFC after: 1 week
Diffstat (limited to 'lib')
-rw-r--r-- | lib/libc/stdtime/Makefile.inc | 3 | ||||
-rw-r--r-- | lib/libc/stdtime/time32.c | 60 |
2 files changed, 62 insertions, 1 deletions
diff --git a/lib/libc/stdtime/Makefile.inc b/lib/libc/stdtime/Makefile.inc index 36f909f..f9abc71 100644 --- a/lib/libc/stdtime/Makefile.inc +++ b/lib/libc/stdtime/Makefile.inc @@ -3,7 +3,8 @@ .PATH: ${.CURDIR}/../libc/stdtime ${.CURDIR}/../locale -SRCS+= asctime.c difftime.c localtime.c strftime.c strptime.c timelocal.c +SRCS+= asctime.c difftime.c localtime.c strftime.c strptime.c timelocal.c \ + time32.c .if ${LIB} == "c" MAN+= ctime.3 strftime.3 strptime.3 time2posix.3 diff --git a/lib/libc/stdtime/time32.c b/lib/libc/stdtime/time32.c new file mode 100644 index 0000000..4886f7c --- /dev/null +++ b/lib/libc/stdtime/time32.c @@ -0,0 +1,60 @@ +/*- + * Copyright (c) 2001 FreeBSD Inc. + * All rights reserved. + * + * These routines are for converting time_t to fixed-bit representations + * for use in protocols or storage. When converting time to a larger + * representation of time_t these routines are expected to assume temporal + * locality and use the 50-year rule to properly set the msb bits. XXX + * + * Redistribution and use under the terms of the COPYRIGHT file at the + * base of the source tree. + * + * $FreeBSD$ + */ + +#include <sys/types.h> +#include <sys/time.h> + +/* + * Convert a 32 bit representation of time_t into time_t. XXX needs to + * implement the 50-year rule to handle post-2038 conversions. + */ +time_t +time32_to_time(__int32_t t32) +{ + return((time_t)t32); +} + +/* + * Convert time_t to a 32 bit representation. If time_t is 64 bits we can + * simply chop it down. The resulting 32 bit representation can be + * converted back to a temporally local 64 bit time_t using time32_to_time. + */ +__int32_t +time_to_time32(time_t t) +{ + return((__int32_t)t); +} + +/* + * Convert a 64 bit representation of time_t into time_t. If time_t is + * represented as 32 bits we can simply chop it and not support times + * past 2038. + */ +time_t +time64_to_time(__int64_t t64) +{ + return((time_t)t64); +} + +/* + * Convert time_t to a 64 bit representation. If time_t is represented + * as 32 bits we simply sign-extend and do not support times past 2038. + */ +__int64_t +time_to_time64(time_t t) +{ + return((__int64_t)t); +} + |