emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

libbb: code shrink parse_datestr

Browse Source 
The default build uses strptime() in parse_datestr() to support the
'month_name d HH:MM:SS YYYY' format of GNU date.  If we've linked
with strptime() there's an advantage is using it for other formats
too.

There's no change to the non-default, non-DESKTOP build.

function                                             old     new   delta
fmt_str                                                -     106    +106
.rodata                                            99216   99145     -71
parse_datestr                                        948     624    -324
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 106/-395)         Total: -289 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Ron Yorston 2021-09-14 08:52:49 +01:00 committed by Denys Vlasenko
parent 5726df5f94
commit 3512ef8018
1 changed files with 36 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
libbb/time.c
View File

@ -11,13 +11,45 @@
void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
{
char end = '\0';
#if ENABLE_DESKTOP
/*
* strptime is BIG: ~1k in uclibc, ~10k in glibc
* We need it for 'month_name d HH:MM:SS YYYY', supported by GNU date,
* but if we've linked it we might as well use it for everything.
*/
static const char fmt_str[] ALIGN1 =
"%R" "\0" /* HH:MM */
"%T" "\0" /* HH:MM:SS */
"%m.%d-%R" "\0" /* mm.dd-HH:MM */
"%m.%d-%T" "\0" /* mm.dd-HH:MM:SS */
"%Y.%m.%d-%R" "\0" /* yyyy.mm.dd-HH:MM */
"%Y.%m.%d-%T" "\0" /* yyyy.mm.dd-HH:MM:SS */
"%b %d %T %Y" "\0" /* month_name d HH:MM:SS YYYY */
"%Y-%m-%d %R" "\0" /* yyyy-mm-dd HH:MM */
"%Y-%m-%d %T" "\0" /* yyyy-mm-dd HH:MM:SS */
"%Y-%m-%d %H" "\0" /* yyyy-mm-dd HH */
"%Y-%m-%d" "\0" /* yyyy-mm-dd */
/* extra NUL */;
struct tm save;
const char *fmt;
char *endp;
save = *ptm;
fmt = fmt_str;
while (*fmt) {
endp = strptime(date_str, fmt, ptm);
if (endp && *endp == '\0')
return;
*ptm = save;
while (*++fmt)
continue;
++fmt;
}
#else
const char *last_colon = strrchr(date_str, ':');
if (last_colon != NULL) {
/* Parse input and assign appropriately to ptm */
#if ENABLE_DESKTOP
const char *endp;
#endif
/* HH:MM */
if (sscanf(date_str, "%u:%u%c",
@ -50,14 +82,6 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
ptm->tm_year -= 1900; /* Adjust years */
ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
} else
#if ENABLE_DESKTOP /* strptime is BIG: ~1k in uclibc, ~10k in glibc */
/* month_name d HH:MM:SS YYYY. Supported by GNU date */
if ((endp = strptime(date_str, "%b %d %T %Y", ptm)) != NULL
&& *endp == '\0'
) {
return; /* don't fall through to end == ":" check */
} else
#endif
{
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
}
@ -89,6 +113,7 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
ptm->tm_year -= 1900; /* Adjust years */
ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
} else
#endif /* ENABLE_DESKTOP */
if (date_str[0] == '@') {
time_t t;
if (sizeof(t) <= sizeof(long))