subsurface/time.c
Dirk Hohndel 99846da77f Conversion to gettext to allow localization
This is just the first step - convert the string literals, try to catch
all the places where this isn't possible and the program needs to convert
string constants at runtime (those are the N_ macros).

Add a very rough first German localization so I can at least test what I
have done. Seriously, I have never used a localized OS, so I am certain
that I have many of the 'standard' translations wrong. Someone please take
over :-)

Major issues with this:

- right now it hardcodes the search path for the message catalog to be
  ./locale - that's of course bogus, but it works well while doing initial
  testing. Once the tooling support is there we just should use the OS
  default.

- even though de_DE defaults to ISO-8859-15 (or ISO-8859-1 - the internets
  can't seem to agree) I went with UTF-8 as that is what Gtk appears to
  want to use internally. ISO-8859-15 encoded .mo files create funny
  looking artefacts instead of Umlaute.

- no support at all in the Makefile - I was hoping someone with more
  experience in how to best set this up would contribute a good set of
  Makefile rules - likely this will help fix the first issue in that it
  will also install the .mo file(s) in the correct place(s)

  For now simply run

  msgfmt -c -o subsurface.mo deutsch.po

  to create the subsurface.mo file and then move it to
  ./locale/de_DE.UTF-8/LC_MESSAGES/subsurface.mo

  If you make changes to the sources and need to add new strings to be
  translated, this is what seems to work (again, should be tooled through
  the Makefile):

  xgettext -o subsurface-new.pot -s -k_ -kN_ --add-comments="++GETTEXT" *.c
  msgmerge -s -U po/deutsch.po subsurface-new.pot

  If you do this PLEASE do one commit that just has the new msgid as
  changes in line numbers create a TON of diff-noise. Do changes to
  translations in a SEPARATE commit.

- no testing at all on Windows or Mac
  It builds on Windows :-)

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2012-10-11 10:03:03 +09:00

99 lines
2.2 KiB
C

#include <glib/gi18n.h>
#include <string.h>
#include "dive.h"
/*
* Convert 64-bit timestamp to 'struct tm' in UTC.
*
* On 32-bit machines, only do 64-bit arithmetic for the seconds
* part, after that we do everything in 'long'. 64-bit divides
* are unnecessary once you're counting minutes (32-bit minutes:
* 8000+ years).
*/
void utc_mkdate(timestamp_t timestamp, struct tm *tm)
{
static const int mdays[] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
};
static const int mdays_leap[] = {
31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
};
unsigned long val;
unsigned int leapyears;
int m;
const int *mp;
memset(tm, 0, sizeof(*tm));
/* seconds since 1970 -> minutes since 1970 */
tm->tm_sec = timestamp % 60;
val = timestamp /= 60;
/* Do the simple stuff */
tm->tm_min = val % 60; val /= 60;
tm->tm_hour = val % 24; val /= 24;
/* Jan 1, 1970 was a Thursday (tm_wday=4) */
tm->tm_wday = (val+4) % 7;
/*
* Now we're in "days since Jan 1, 1970". To make things easier,
* let's make it "days since Jan 1, 1968", since that's a leap-year
*/
val += 365+366;
/* This only works up until 2099 (2100 isn't a leap-year) */
leapyears = val / (365*4+1);
val %= (365*4+1);
tm->tm_year = 68 + leapyears * 4;
/* Handle the leap-year itself */
mp = mdays_leap;
if (val > 365) {
tm->tm_year++;
val -= 366;
tm->tm_year += val / 365;
val %= 365;
mp = mdays;
}
for (m = 0; m < 12; m++) {
if (val < *mp)
break;
val -= *mp++;
}
tm->tm_mday = val+1;
tm->tm_mon = m;
}
timestamp_t utc_mktime(struct tm *tm)
{
static const int mdays[] = {
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};
int year = tm->tm_year;
int month = tm->tm_mon;
int day = tm->tm_mday;
/* First normalize relative to 1900 */
if (year < 70)
year += 100;
else if (year > 1900)
year -= 1900;
/* Normalized to Jan 1, 1970: unix time */
year -= 70;
if (year < 0 || year > 129) /* algo only works for 1970-2099 */
return -1;
if (month < 0 || month > 11) /* array bounds */
return -1;
if (month < 2 || (year + 2) % 4)
day--;
if (tm->tm_hour < 0 || tm->tm_min < 0 || tm->tm_sec < 0)
return -1;
return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
}