2004-12-13
2004-12-13 19:37:30 by Martin Stjernholm <mast@lysator.liu.se>
-
603ba1a073a4e9d290b8c9169e5d850f52ae70e1
(200 lines)
(+141/-59)
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Branch: 7.4
Fixed mktime() to work before 1970 even when the system mktime(3) doesn't.
Fixed the gmtime inverse function to work for localtime too. It also maps to
the closest valid time when given an invalid time, just like mktime(3)
usually does.
Rev: src/builtin_functions.c:1.471
2:
|| This file is part of Pike. For copyright information see COPYRIGHT.
|| Pike is distributed under GPL, LGPL and MPL. See the file COPYING
|| for more information.
- || $Id: builtin_functions.c,v 1.470 2004/12/08 15:16:34 mast Exp $
+ || $Id: builtin_functions.c,v 1.471 2004/12/13 19:37:30 mast Exp $
*/
#include "global.h"
- RCSID("$Id: builtin_functions.c,v 1.470 2004/12/08 15:16:34 mast Exp $");
+ RCSID("$Id: builtin_functions.c,v 1.471 2004/12/13 19:37:30 mast Exp $");
#include "interpret.h"
#include "svalue.h"
#include "pike_macros.h"
4155:
}
#endif
- #ifdef HAVE_GMTIME
+ #if defined (HAVE_GMTIME) || defined (HAVE_LOCALTIME)
/* Returns the approximate difference in seconds between the
* two struct tm's.
*/
static time_t my_tm_diff(const struct tm *t1, const struct tm *t2)
{
- time_t base = (t1->tm_year - t2->tm_year) * 32140800 +
+ time_t base = (t1->tm_year - t2->tm_year) * 32140800;
+
+ /* Overflow detection. (Should possibly be done on the other fields
+ * too to cope with very large invalid dates.) */
+ if ((t1->tm_year > t2->tm_year) && (base < 0))
+ return 0x7fffffff;
+ if ((t1->tm_year < t2->tm_year) && (base > 0))
+ return -0x7fffffff;
+
+ base +=
(t1->tm_mon - t2->tm_mon) * 2678400 +
(t1->tm_mday - t2->tm_mday) * 86400 +
(t1->tm_hour - t2->tm_hour) * 3600 +
(t1->tm_min - t2->tm_min) * 60 +
(t1->tm_sec - t2->tm_sec);
- if ((t1->tm_year > t2->tm_year) && (base < 0))
- return 0x7fffffff;
- if ((t1->tm_year < t2->tm_year) && (base > 0))
- return -0x7fffffff;
+
return base;
}
- /* Inverse operation of gmtime().
+ typedef struct tm *time_fn (const time_t *);
+
+ /* Inverse operation of gmtime or localtime.
*/
- static time_t my_timegm(struct tm *target_tm)
+ static int my_time_inverse (struct tm *target_tm, time_t *result, time_fn timefn)
{
time_t current_ts = 0;
- time_t diff_ts;
+ time_t diff_ts, old_diff_ts = 0;
struct tm *current_tm;
- int loop_cnt = 0;
+ int loop_cnt, tried_dst_displacement = 0;
/* This loop seems stable, and usually converges in two passes.
* The loop counter is for paranoia reasons.
*/
- while((diff_ts = my_tm_diff(target_tm, current_tm = gmtime(¤t_ts)))) {
+ for (loop_cnt = 0; loop_cnt < 20; loop_cnt++, old_diff_ts = diff_ts) {
+ diff_ts = my_tm_diff(target_tm, current_tm = timefn(¤t_ts));
+
+ #ifdef DEBUG_MY_TIME_INVERSE
+ fprintf (stderr, "curr: y %d m %d d %d h %d m %d isdst %d\n",
+ current_tm->tm_year, current_tm->tm_mon, current_tm->tm_mday,
+ current_tm->tm_hour, current_tm->tm_min, current_tm->tm_isdst);
+ fprintf (stderr, "diff: %d\n", diff_ts);
+ #endif
+
+ if (!diff_ts) {
+ /* Got a satisfactory time, but if target_tm has an opinion on
+ * DST we should check if we can return an alternative in the
+ * same DST zone, to cope with the overlapping DST adjustment at
+ * fall. */
+ if (target_tm->tm_isdst >= 0 &&
+ target_tm->tm_isdst != current_tm->tm_isdst &&
+ !tried_dst_displacement) {
+ /* Offset the time a day and iterate some more (only once
+ * more, really), so that we approach the target time from the
+ * right direction. */
+ if (target_tm->tm_isdst)
+ current_ts -= 24 * 3600;
+ else
+ current_ts += 24 * 3600;
+ tried_dst_displacement = 1;
+ #ifdef DEBUG_MY_TIME_INVERSE
+ fprintf (stderr, "dst displacement\n");
+ #endif
+ continue;
+ }
+ break;
+ }
+
+ if (diff_ts == -old_diff_ts) {
+ /* We're oscillating, which means the time in target_tm is
+ * invalid. mktime(3) maps to the closest "convenient" valid
+ * time in that case, so let's do that too. */
+ if (diff_ts > -24 * 3600 && diff_ts < 24 * 3600) {
+ /* The oscillation is not whole days, so it must be due to the
+ * DST gap in the spring. Prefer the same DST zone as the
+ * target tm, if it has one set. */
+ if (target_tm->tm_isdst >= 0) {
+ if (target_tm->tm_isdst != current_tm->tm_isdst)
current_ts += diff_ts;
- loop_cnt++;
- /* fprintf(stderr, "Loop [%d]: %d, %d\n", loop_cnt, current_ts, diff_ts); */
- if (loop_cnt > 20) {
- /* Infinite loop? */
- return -1;
+ #ifdef DEBUG_MY_TIME_INVERSE
+ fprintf (stderr, "spring dst gap\n");
+ #endif
+ break;
}
}
- /* Check that the result tm looks like what we expect... */
- if ((current_tm->tm_sec == target_tm->tm_sec) &&
- (current_tm->tm_min == target_tm->tm_min)) {
- /* Odds are that the rest of the fields are correct (1:3600). */
- return current_ts;
+ /* The oscillation is due to the gap between the 31 day months
+ * used in my_tm_diff and the actual month lengths. In that case
+ * it's correct to always go forward so that e.g. April 31st
+ * maps to May 1st. */
+ if (diff_ts > 0)
+ current_ts += diff_ts;
+ #ifdef DEBUG_MY_TIME_INVERSE
+ fprintf (stderr, "end of month gap\n");
+ #endif
+ break;
}
- return -1;
+
+ current_ts += diff_ts;
}
- #endif /* HAVE_GMTIME */
+
- #ifdef HAVE_MKTIME
+ #ifdef DEBUG_MY_TIME_INVERSE
+ fprintf (stderr, "res: y %d m %d d %d h %d m %d isdst %d\n",
+ current_tm->tm_year, current_tm->tm_mon, current_tm->tm_mday,
+ current_tm->tm_hour, current_tm->tm_min, current_tm->tm_isdst);
+ #endif
+ *result = current_ts;
+ return 1;
+ }
+ #endif /* HAVE_GMTIME || HAVE_LOCALTIME */
+
+ #if defined (HAVE_MKTIME) || defined (HAVE_LOCALTIME)
/*! @decl int mktime(mapping(string:int) tm)
*! @decl int mktime(int sec, int min, int hour, int mday, int mon, int year, @
*! int isdst, int tz)
4251: Inside #if defined(HAVE_MKTIME)
{
INT_TYPE sec, min, hour, mday, mon, year;
struct tm date;
- int retval;
+ time_t retval;
if (args<1)
SIMPLE_TOO_FEW_ARGS_ERROR("mktime", 1);
4308: Inside #if defined(HAVE_MKTIME) and #if defined(HAVE_GMTIME)
#ifdef HAVE_GMTIME
if ((args > 7) && (Pike_sp[7-args].subtype == NUMBER_NUMBER))
{
- /* UTC-relative time. Use my_timegm(). */
- retval = my_timegm(&date);
- if (retval == -1)
+ /* UTC-relative time. Use gmtime. */
+ if (!my_time_inverse (&date, &retval, gmtime))
PIKE_ERROR("mktime", "Time conversion failed.\n", Pike_sp, args);
retval += Pike_sp[7-args].u.integer;
- } else {
+ } else
#endif /* HAVE_GMTIME */
-
+ {
+ #ifdef HAVE_MKTIME
+
#ifdef STRUCT_TM_HAS_GMTOFF
/* BSD-style */
date.tm_gmtoff = 0;
4329: Inside #if defined(HAVE_MKTIME)
/* Pre-adjust for the timezone.
*
* Note that pre-adjustment must be done on AIX for dates
- * near Jan 1, 1970, sine AIX mktime(3) doesn't support
+ * near Jan 1, 1970, since AIX mktime(3) doesn't support
* negative time.
*/
date.tm_sec += Pike_sp[7-args].u.integer
4343:
retval = mktime(&date);
- if (retval == -1)
- PIKE_ERROR("mktime", "Cannot convert.\n", Pike_sp, args);
-
+ if (retval != -1) {
#if defined(STRUCT_TM_HAS_GMTOFF) || defined(STRUCT_TM_HAS___TM_GMTOFF)
if((args > 7) && (Pike_sp[7-args].subtype == NUMBER_NUMBER))
{
4367:
(Pike_sp[6-args].u.integer != -1) &&
(Pike_sp[6-args].u.integer != date.tm_isdst)) {
/* Some stupid libc's (Hi Linux!) don't accept that we've set isdst... */
+ #ifdef HAVE_LOCALTIME
+ if (!my_time_inverse (&date, &retval, localtime))
+ PIKE_ERROR("mktime", "Time conversion unsuccessful.\n", Pike_sp, args);
+ #else
+ /* Last resort: Assumes a one hour DST. */
retval += 3600 * (Pike_sp[6-args].u.integer - date.tm_isdst);
-
+ #endif
}
#endif /* STRUCT_TM_HAS_GMTOFF || STRUCT_TM_HAS___TM_GMTOFF */
- #ifdef HAVE_GMTIME
+
}
- #endif /* HAVE_GMTIME */
+ else
+ #endif /* HAVE_MKTIME */
-
+ {
+ #ifdef HAVE_LOCALTIME
+ /* mktime might fail on dates before 1970 (GNU libc 2.3.2), so
+ * try our own inverse function with localtime. */
+ if (!my_time_inverse (&date, &retval, localtime))
+ #endif
+ PIKE_ERROR("mktime", "Time conversion unsuccessful.\n", Pike_sp, args);
+ }
+ }
+
pop_n_elems(args);
push_int(retval);
}
-
+ #define GOT_F_MKTIME
+ #endif /* HAVE_MKTIME || HAVE_LOCALTIME */
- #endif
-
+
/* Parse a sprintf/sscanf-style format string */
static ptrdiff_t low_parse_format(p_wchar0 *s, ptrdiff_t slen)
{
8053:
ADD_EFUN("gmtime",f_gmtime,tFunc(tInt,tMap(tStr,tInt)),OPT_EXTERNAL_DEPEND);
#endif
- #ifdef HAVE_MKTIME
+ #ifdef GOT_F_MKTIME
/* function(int,int,int,int,int,int,int,void|int:int)|function(object|mapping:int) */
ADD_EFUN("mktime",f_mktime,