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2875cd24db
corner cases that come up in certain timezones (apparently, only those with lots and lots of distinct TZ transition rules, as far as I can gather from a quick scan of their archives). Per suggestion from Jeevan Chalke. Back-patch to 8.4. Possibly we need to push this into earlier releases as well, but I'm hesitant to update them to the 64-bit tzcode without more thought and testing.
527 lines
13 KiB
C
527 lines
13 KiB
C
/*
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* Copyright (c) 1989 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/timezone/strftime.c,v 1.14.2.1 2010/03/11 18:43:32 tgl Exp $
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*/
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#include "postgres.h"
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#include <fcntl.h>
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#include <locale.h>
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#include "private.h"
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#include "tzfile.h"
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struct lc_time_T
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{
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const char *mon[MONSPERYEAR];
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const char *month[MONSPERYEAR];
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const char *wday[DAYSPERWEEK];
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const char *weekday[DAYSPERWEEK];
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const char *X_fmt;
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const char *x_fmt;
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const char *c_fmt;
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const char *am;
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const char *pm;
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const char *date_fmt;
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};
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#define Locale (&C_time_locale)
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static const struct lc_time_T C_time_locale = {
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{
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"Jan", "Feb", "Mar", "Apr", "May", "Jun",
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"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
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}, {
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"January", "February", "March", "April", "May", "June",
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"July", "August", "September", "October", "November", "December"
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}, {
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"Sun", "Mon", "Tue", "Wed",
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"Thu", "Fri", "Sat"
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}, {
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"Sunday", "Monday", "Tuesday", "Wednesday",
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"Thursday", "Friday", "Saturday"
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},
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/* X_fmt */
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"%H:%M:%S",
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/*
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* x_fmt
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*
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* C99 requires this format. Using just numbers (as here) makes Quakers
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* happier; it's also compatible with SVR4.
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*/
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"%m/%d/%y",
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/*
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* c_fmt
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*
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* C99 requires this format. Previously this code used "%D %X", but we now
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* conform to C99. Note that "%a %b %d %H:%M:%S %Y" is used by Solaris
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* 2.3.
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*/
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"%a %b %e %T %Y",
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/* am */
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"AM",
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/* pm */
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"PM",
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/* date_fmt */
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"%a %b %e %H:%M:%S %Z %Y"
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};
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static char *_add(const char *, char *, const char *);
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static char *_conv(int, const char *, char *, const char *);
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static char *_fmt(const char *, const struct pg_tm *, char *,
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const char *, int *);
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static char *_yconv(const int, const int, const int, const int,
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char *, const char *const);
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#define IN_NONE 0
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#define IN_SOME 1
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#define IN_THIS 2
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#define IN_ALL 3
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size_t
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pg_strftime(char *s, size_t maxsize, const char *format,
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const struct pg_tm * t)
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{
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char *p;
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int warn;
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warn = IN_NONE;
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p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn);
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if (p == s + maxsize)
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return 0;
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*p = '\0';
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return p - s;
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}
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static char *
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_fmt(const char *format, const struct pg_tm * t, char *pt, const char *ptlim,
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int *warnp)
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{
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for (; *format; ++format)
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{
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if (*format == '%')
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{
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label:
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switch (*++format)
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{
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case '\0':
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--format;
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break;
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case 'A':
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pt = _add((t->tm_wday < 0 ||
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t->tm_wday >= DAYSPERWEEK) ?
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"?" : Locale->weekday[t->tm_wday],
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pt, ptlim);
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continue;
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case 'a':
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pt = _add((t->tm_wday < 0 ||
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t->tm_wday >= DAYSPERWEEK) ?
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"?" : Locale->wday[t->tm_wday],
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pt, ptlim);
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continue;
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case 'B':
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pt = _add((t->tm_mon < 0 ||
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t->tm_mon >= MONSPERYEAR) ?
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"?" : Locale->month[t->tm_mon],
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pt, ptlim);
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continue;
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case 'b':
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case 'h':
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pt = _add((t->tm_mon < 0 ||
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t->tm_mon >= MONSPERYEAR) ?
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"?" : Locale->mon[t->tm_mon],
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pt, ptlim);
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continue;
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case 'C':
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/*
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* %C used to do a... _fmt("%a %b %e %X %Y", t);
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* ...whereas now POSIX 1003.2 calls for something
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* completely different. (ado, 1993-05-24)
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*/
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pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
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pt, ptlim);
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continue;
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case 'c':
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{
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int warn2 = IN_SOME;
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pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
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if (warn2 == IN_ALL)
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warn2 = IN_THIS;
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if (warn2 > *warnp)
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*warnp = warn2;
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}
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continue;
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case 'D':
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pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
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continue;
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case 'd':
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pt = _conv(t->tm_mday, "%02d", pt, ptlim);
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continue;
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case 'E':
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case 'O':
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/*
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* C99 locale modifiers. The sequences %Ec %EC %Ex %EX
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* %Ey %EY %Od %oe %OH %OI %Om %OM %OS %Ou %OU %OV %Ow
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* %OW %Oy are supposed to provide alternate
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* representations.
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*/
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goto label;
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case 'e':
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pt = _conv(t->tm_mday, "%2d", pt, ptlim);
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continue;
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case 'F':
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pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
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continue;
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case 'H':
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pt = _conv(t->tm_hour, "%02d", pt, ptlim);
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continue;
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case 'I':
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pt = _conv((t->tm_hour % 12) ?
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(t->tm_hour % 12) : 12,
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"%02d", pt, ptlim);
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continue;
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case 'j':
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pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
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continue;
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case 'k':
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/*
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* This used to be... _conv(t->tm_hour % 12 ? t->tm_hour
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* % 12 : 12, 2, ' '); ...and has been changed to the
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* below to match SunOS 4.1.1 and Arnold Robbins' strftime
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* version 3.0. That is, "%k" and "%l" have been swapped.
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* (ado, 1993-05-24)
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*/
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pt = _conv(t->tm_hour, "%2d", pt, ptlim);
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continue;
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#ifdef KITCHEN_SINK
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case 'K':
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/*
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* * After all this time, still unclaimed!
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*/
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pt = _add("kitchen sink", pt, ptlim);
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continue;
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#endif /* defined KITCHEN_SINK */
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case 'l':
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/*
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* This used to be... _conv(t->tm_hour, 2, ' '); ...and
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* has been changed to the below to match SunOS 4.1.1 and
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* Arnold Robbin's strftime version 3.0. That is, "%k" and
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* "%l" have been swapped. (ado, 1993-05-24)
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*/
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pt = _conv((t->tm_hour % 12) ?
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(t->tm_hour % 12) : 12,
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"%2d", pt, ptlim);
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continue;
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case 'M':
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pt = _conv(t->tm_min, "%02d", pt, ptlim);
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continue;
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case 'm':
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pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
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continue;
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case 'n':
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pt = _add("\n", pt, ptlim);
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continue;
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case 'p':
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pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
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Locale->pm :
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Locale->am,
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pt, ptlim);
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continue;
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case 'R':
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pt = _fmt("%H:%M", t, pt, ptlim, warnp);
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continue;
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case 'r':
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pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
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continue;
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case 'S':
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pt = _conv(t->tm_sec, "%02d", pt, ptlim);
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continue;
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case 'T':
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pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
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continue;
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case 't':
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pt = _add("\t", pt, ptlim);
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continue;
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case 'U':
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pt = _conv((t->tm_yday + DAYSPERWEEK -
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t->tm_wday) / DAYSPERWEEK,
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"%02d", pt, ptlim);
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continue;
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case 'u':
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/*
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* From Arnold Robbins' strftime version 3.0: "ISO 8601:
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* Weekday as a decimal number [1 (Monday) - 7]" (ado,
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* 1993-05-24)
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*/
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pt = _conv((t->tm_wday == 0) ?
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DAYSPERWEEK : t->tm_wday,
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"%d", pt, ptlim);
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continue;
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case 'V': /* ISO 8601 week number */
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case 'G': /* ISO 8601 year (four digits) */
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case 'g': /* ISO 8601 year (two digits) */
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/*
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* From Arnold Robbins' strftime version 3.0: "the week number of the
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* year (the first Monday as the first day of week 1) as a decimal number
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* (01-53)."
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* (ado, 1993-05-24)
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*
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* From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
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* "Week 01 of a year is per definition the first week which has the
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* Thursday in this year, which is equivalent to the week which contains
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* the fourth day of January. In other words, the first week of a new year
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* is the week which has the majority of its days in the new year. Week 01
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* might also contain days from the previous year and the week before week
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* 01 of a year is the last week (52 or 53) of the previous year even if
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* it contains days from the new year. A week starts with Monday (day 1)
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* and ends with Sunday (day 7). For example, the first week of the year
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* 1997 lasts from 1996-12-30 to 1997-01-05..."
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* (ado, 1996-01-02)
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*/
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{
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int year;
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int base;
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int yday;
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int wday;
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int w;
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year = t->tm_year;
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base = TM_YEAR_BASE;
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yday = t->tm_yday;
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wday = t->tm_wday;
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for (;;)
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{
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int len;
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int bot;
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int top;
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len = isleap_sum(year, base) ?
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DAYSPERLYEAR :
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DAYSPERNYEAR;
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/*
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* What yday (-3 ... 3) does the ISO year begin
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* on?
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*/
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bot = ((yday + 11 - wday) %
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DAYSPERWEEK) - 3;
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/*
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* What yday does the NEXT ISO year begin on?
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*/
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top = bot -
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(len % DAYSPERWEEK);
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if (top < -3)
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top += DAYSPERWEEK;
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top += len;
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if (yday >= top)
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{
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++base;
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w = 1;
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break;
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}
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if (yday >= bot)
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{
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w = 1 + ((yday - bot) /
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DAYSPERWEEK);
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break;
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}
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--base;
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yday += isleap_sum(year, base) ?
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DAYSPERLYEAR :
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DAYSPERNYEAR;
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}
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if (*format == 'V')
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pt = _conv(w, "%02d",
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pt, ptlim);
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else if (*format == 'g')
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{
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*warnp = IN_ALL;
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pt = _yconv(year, base, 0, 1,
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pt, ptlim);
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}
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else
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pt = _yconv(year, base, 1, 1,
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pt, ptlim);
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}
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continue;
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case 'v':
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/*
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* From Arnold Robbins' strftime version 3.0: "date as
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* dd-bbb-YYYY" (ado, 1993-05-24)
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*/
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pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
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continue;
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case 'W':
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pt = _conv((t->tm_yday + DAYSPERWEEK -
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(t->tm_wday ?
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(t->tm_wday - 1) :
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(DAYSPERWEEK - 1))) / DAYSPERWEEK,
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"%02d", pt, ptlim);
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continue;
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case 'w':
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pt = _conv(t->tm_wday, "%d", pt, ptlim);
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continue;
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case 'X':
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pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
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continue;
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case 'x':
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{
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int warn2 = IN_SOME;
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pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
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if (warn2 == IN_ALL)
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warn2 = IN_THIS;
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if (warn2 > *warnp)
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*warnp = warn2;
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}
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continue;
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case 'y':
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*warnp = IN_ALL;
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pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
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pt, ptlim);
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continue;
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case 'Y':
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pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
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pt, ptlim);
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continue;
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case 'Z':
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if (t->tm_zone != NULL)
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pt = _add(t->tm_zone, pt, ptlim);
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/*
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* C99 says that %Z must be replaced by the empty string
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* if the time zone is not determinable.
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*/
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continue;
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case 'z':
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{
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int diff;
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char const *sign;
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if (t->tm_isdst < 0)
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continue;
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diff = t->tm_gmtoff;
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if (diff < 0)
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{
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sign = "-";
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diff = -diff;
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}
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else
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sign = "+";
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pt = _add(sign, pt, ptlim);
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diff /= 60;
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pt = _conv((diff / 60) * 100 + diff % 60,
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"%04d", pt, ptlim);
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}
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continue;
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case '+':
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pt = _fmt(Locale->date_fmt, t, pt, ptlim,
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warnp);
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continue;
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case '%':
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/*
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* X311J/88-090 (4.12.3.5): if conversion char is
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* undefined, behavior is undefined. Print out the
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* character itself as printf(3) also does.
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*/
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default:
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break;
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}
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}
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if (pt == ptlim)
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break;
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*pt++ = *format;
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}
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return pt;
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}
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static char *
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_conv(int n, const char *format, char *pt, const char *ptlim)
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{
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char buf[INT_STRLEN_MAXIMUM(int) +1];
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(void) sprintf(buf, format, n);
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return _add(buf, pt, ptlim);
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}
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static char *
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_add(const char *str, char *pt, const char *ptlim)
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{
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while (pt < ptlim && (*pt = *str++) != '\0')
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++pt;
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return pt;
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}
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/*
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* POSIX and the C Standard are unclear or inconsistent about
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* what %C and %y do if the year is negative or exceeds 9999.
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* Use the convention that %C concatenated with %y yields the
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* same output as %Y, and that %Y contains at least 4 bytes,
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* with more only if necessary.
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*/
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static char *
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_yconv(const int a, const int b, const int convert_top,
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const int convert_yy, char *pt, const char *const ptlim)
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{
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int lead;
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int trail;
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#define DIVISOR 100
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trail = a % DIVISOR + b % DIVISOR;
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lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
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trail %= DIVISOR;
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if (trail < 0 && lead > 0)
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{
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trail += DIVISOR;
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--lead;
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}
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else if (lead < 0 && trail > 0)
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{
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trail -= DIVISOR;
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++lead;
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}
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if (convert_top)
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{
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if (lead == 0 && trail < 0)
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pt = _add("-0", pt, ptlim);
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else
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pt = _conv(lead, "%02d", pt, ptlim);
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}
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if (convert_yy)
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pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
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return pt;
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}
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