mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 15:03:34 +00:00
cfc3a953ae
This change makes strftime() go faster and makes it possible to format timestamps through the big bang to most of the stelliferous era. India has also been added as a timezone to most binaries. Since we were able to change the struct tm abi, this makes cosmopolitan libc superior, to just about everything else, when it comes to standing the test of time
634 lines
16 KiB
C
634 lines
16 KiB
C
/*-*- mode:c; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
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│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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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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#include "libc/bits/pushpop.h"
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#include "libc/fmt/itoa.h"
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#include "libc/inttypes.h"
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#include "libc/stdio/stdio.h"
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#include "libc/str/str.h"
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#include "libc/time/time.h"
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#include "libc/time/tz.internal.h"
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#include "libc/unicode/locale.h"
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// clang-format off
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// converts broken-down timestamp to string
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#define DIVISOR 100
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asm(".ident\t\"\\n\\n\
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strftime (BSD-3)\\n\
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Copyright 1989 The Regents of the University of California\"");
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asm(".include \"libc/disclaimer.inc\"");
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/*
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** Based on the UCB version with the copyright notice appearing above.
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**
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** This is ANSIish only when "multibyte character == plain character".
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*/
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struct lc_time_T {
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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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** C99 and later require this format.
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** Using just numbers (as here) makes Quakers happier;
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** 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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** C99 and later require this format.
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** Previously this code used "%D %X", but we now conform to C99.
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** Note that
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** "%a %b %d %H:%M:%S %Y"
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** is used by Solaris 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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enum warn { IN_NONE, IN_SOME, IN_THIS, IN_ALL };
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#ifndef YEAR_2000_NAME
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#define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
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#endif /* !defined YEAR_2000_NAME */
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static char *
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strftime_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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static dontinline char *
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strftime_conv(int64_t x, char *pt, const char *ptlim, int width, char pad)
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{
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int n;
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char buf[21], *ptr, *end;
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end = FormatInt64(buf, x);
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for (n = width - (end - buf); n > 0; --n) {
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if (pt < ptlim) {
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*pt++ = pad;
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}
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}
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return strftime_add(buf, pt, ptlim);
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}
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static dontinline char *
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strftime_conv_d(int64_t n, char *pt, const char *ptlim)
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{
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return strftime_conv(n, pt, ptlim, 0, 0);
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}
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static dontinline char *
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strftime_conv_2d(int64_t n, char *pt, const char *ptlim)
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{
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return strftime_conv(n, pt, ptlim, pushpop(2L), pushpop(' '));
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}
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static dontinline char *
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strftime_conv_0(int64_t n, char *pt, const char *ptlim, int width)
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{
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return strftime_conv(n, pt, ptlim, width, pushpop('0'));
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}
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static dontinline char *
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strftime_conv_02d(int64_t n, char *pt, const char *ptlim)
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{
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return strftime_conv_0(n, pt, ptlim, pushpop(2L));
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}
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static dontinline char *
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strftime_conv_03d(int64_t n, char *pt, const char *ptlim)
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{
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return strftime_conv_0(n, pt, ptlim, pushpop(3L));
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}
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static dontinline char *
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strftime_conv_04d(int64_t n, char *pt, const char *ptlim)
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{
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return strftime_conv_0(n, pt, ptlim, pushpop(4L));
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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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strftime_yconv(
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int64_t a,
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int64_t b,
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bool convert_top,
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bool convert_yy,
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char *pt,
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const char *ptlim)
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{
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int64_t lead;
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int64_t trail;
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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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trail += DIVISOR;
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--lead;
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} else if (lead < 0 && trail > 0) {
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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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if (lead == 0 && trail < 0)
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pt = strftime_add("-0", pt, ptlim);
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else pt = strftime_conv_02d(lead, pt, ptlim);
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}
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if (convert_yy)
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pt = strftime_conv_02d(((trail < 0) ? -trail : trail), pt, ptlim);
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return pt;
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}
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static char *
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strftime_fmt(const char *format, const struct tm *t, char *pt,
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const char *ptlim, enum warn *warnp)
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{
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for ( ; *format; ++format) {
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if (*format == '%') {
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label:
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switch (*++format) {
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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 = strftime_add(
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(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 = strftime_add(
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(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 = strftime_add(
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(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 = strftime_add(
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(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...
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** _fmt("%a %b %e %X %Y", t);
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** ...whereas now POSIX 1003.2 calls for
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** something completely different.
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** (ado, 1993-05-24)
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*/
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pt = strftime_yconv(t->tm_year, TM_YEAR_BASE,
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true, false, pt, ptlim);
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continue;
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case 'c':
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{
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enum warn warn2 = IN_SOME;
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pt = strftime_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 = strftime_fmt("%m/%d/%y", t, pt, ptlim, warnp);
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continue;
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case 'd':
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pt = strftime_conv_02d(t->tm_mday, 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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** Locale modifiers of C99 and later.
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** The sequences
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** %Ec %EC %Ex %EX %Ey %EY
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** %Od %oe %OH %OI %Om %OM
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** %OS %Ou %OU %OV %Ow %OW %Oy
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** are supposed to provide alternative
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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 = strftime_conv_2d(t->tm_mday, pt, ptlim);
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continue;
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case 'F':
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pt = strftime_fmt("%Y-%m-%d", t, pt, ptlim, warnp);
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continue;
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case 'H':
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pt = strftime_conv_02d(t->tm_hour, pt, ptlim);
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continue;
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case 'I':
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pt = strftime_conv_02d((t->tm_hour % 12) ?
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(t->tm_hour % 12) : 12,
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pt, ptlim);
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continue;
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case 'j':
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pt = strftime_conv_03d(t->tm_yday + 1, 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...
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** _conv(t->tm_hour % 12 ?
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** t->tm_hour % 12 : 12, 2, ' ');
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** ...and has been changed to the below to
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** match SunOS 4.1.1 and Arnold Robbins'
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** strftime version 3.0. That is, "%k" and
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** "%l" have been swapped.
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** (ado, 1993-05-24)
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*/
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pt = strftime_conv_2d(t->tm_hour, 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 = strftime_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...
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** _conv(t->tm_hour, 2, ' ');
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** ...and has been changed to the below to
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** match SunOS 4.1.1 and Arnold Robbin's
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** strftime version 3.0. That is, "%k" and
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** "%l" have been swapped.
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** (ado, 1993-05-24)
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*/
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pt = strftime_conv_2d((t->tm_hour % 12) ?
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(t->tm_hour % 12) : 12,
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pt, ptlim);
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continue;
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case 'M':
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pt = strftime_conv_02d(t->tm_min, pt, ptlim);
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continue;
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case 'm':
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pt = strftime_conv_02d(t->tm_mon + 1, pt, ptlim);
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continue;
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case 'n':
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pt = strftime_add("\n", pt, ptlim);
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continue;
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case 'p':
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pt = strftime_add(
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(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 = strftime_fmt("%H:%M", t, pt, ptlim, warnp);
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continue;
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case 'r':
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pt = strftime_fmt("%I:%M:%S %p", t, pt,
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ptlim, warnp);
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continue;
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case 'S':
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pt = strftime_conv_02d(t->tm_sec, pt, ptlim);
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continue;
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case 's':
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{
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struct tm tm;
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char buf[21];
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time_t mkt;
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tm = *t;
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tm.tm_yday = -1;
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mkt = mktime(&tm);
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if (mkt == (time_t) -1) {
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/* Fail unless this -1 represents
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a valid time. */
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struct tm tm_1;
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if (!localtime_r(&mkt, &tm_1))
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return NULL;
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if (!(tm.tm_year == tm_1.tm_year
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&& tm.tm_yday == tm_1.tm_yday
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&& tm.tm_hour == tm_1.tm_hour
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&& tm.tm_min == tm_1.tm_min
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&& tm.tm_sec == tm_1.tm_sec))
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return NULL;
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}
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strftime_conv_d(mkt, pt, ptlim);
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}
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continue;
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case 'T':
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pt = strftime_fmt("%H:%M:%S", t, pt, ptlim, warnp);
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continue;
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case 't':
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pt = strftime_add("\t", pt, ptlim);
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continue;
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case 'U':
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pt = strftime_conv_02d(
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(t->tm_yday + DAYSPERWEEK -
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t->tm_wday) / DAYSPERWEEK,
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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:
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** "ISO 8601: Weekday as a decimal number
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** [1 (Monday) - 7]"
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** (ado, 1993-05-24)
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*/
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pt = strftime_conv_d((t->tm_wday == 0) ?
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DAYSPERWEEK : t->tm_wday,
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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 <https://www.cl.cam.ac.uk/~mgk25/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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int64_t year;
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int64_t base;
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int64_t yday;
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int64_t wday;
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int64_t 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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int64_t len;
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int64_t bot;
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int64_t top;
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len = _isleapsum(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
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** the ISO year begin 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
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** 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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++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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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 += _isleapsum(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 = strftime_conv_02d(
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w, pt, ptlim);
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else if (*format == 'g') {
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*warnp = IN_ALL;
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pt = strftime_yconv(year, base,
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false, true,
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pt, ptlim);
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} else pt = strftime_yconv(year, base,
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true, true,
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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:
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** "date as dd-bbb-YYYY"
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** (ado, 1993-05-24)
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*/
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pt = strftime_fmt("%e-%b-%Y", t, pt, ptlim, warnp);
|
|
continue;
|
|
case 'W':
|
|
pt = strftime_conv_02d(
|
|
(t->tm_yday + DAYSPERWEEK -
|
|
(t->tm_wday ?
|
|
(t->tm_wday - 1) :
|
|
(DAYSPERWEEK - 1))) / DAYSPERWEEK,
|
|
pt, ptlim);
|
|
continue;
|
|
case 'w':
|
|
pt = strftime_conv_d(t->tm_wday, pt, ptlim);
|
|
continue;
|
|
case 'X':
|
|
pt = strftime_fmt(Locale->X_fmt, t, pt, ptlim, warnp);
|
|
continue;
|
|
case 'x':
|
|
{
|
|
enum warn warn2 = IN_SOME;
|
|
|
|
pt = strftime_fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
|
|
if (warn2 == IN_ALL)
|
|
warn2 = IN_THIS;
|
|
if (warn2 > *warnp)
|
|
*warnp = warn2;
|
|
}
|
|
continue;
|
|
case 'y':
|
|
*warnp = IN_ALL;
|
|
pt = strftime_yconv(t->tm_year, TM_YEAR_BASE,
|
|
false, true,
|
|
pt, ptlim);
|
|
continue;
|
|
case 'Y':
|
|
pt = strftime_yconv(t->tm_year, TM_YEAR_BASE,
|
|
true, true,
|
|
pt, ptlim);
|
|
continue;
|
|
case 'Z':
|
|
pt = strftime_add(t->tm_zone, pt, ptlim);
|
|
/*
|
|
** C99 and later say that %Z must be
|
|
** replaced by the empty string if the
|
|
** time zone abbreviation is not
|
|
** determinable.
|
|
*/
|
|
continue;
|
|
case 'z':
|
|
{
|
|
long diff;
|
|
char const * sign;
|
|
bool negative;
|
|
|
|
diff = t->tm_gmtoff;
|
|
negative = diff < 0;
|
|
if (diff == 0) {
|
|
negative = t->tm_zone[0] == '-';
|
|
}
|
|
if (negative) {
|
|
sign = "-";
|
|
diff = -diff;
|
|
} else sign = "+";
|
|
pt = strftime_add(sign, pt, ptlim);
|
|
diff /= SECSPERMIN;
|
|
diff = (diff / MINSPERHOUR) * 100 +
|
|
(diff % MINSPERHOUR);
|
|
pt = strftime_conv_04d(diff, pt, ptlim);
|
|
}
|
|
continue;
|
|
case '+':
|
|
pt = strftime_fmt(Locale->date_fmt, t, pt,
|
|
ptlim, warnp);
|
|
continue;
|
|
case '%':
|
|
/*
|
|
** X311J/88-090 (4.12.3.5): if conversion char is
|
|
** undefined, behavior is undefined. Print out the
|
|
** character itself as printf(3) also does.
|
|
*/
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
if (pt == ptlim)
|
|
break;
|
|
*pt++ = *format;
|
|
}
|
|
return pt;
|
|
}
|
|
|
|
/**
|
|
* Converts time to string, e.g.
|
|
*
|
|
* char b[64];
|
|
* int64_t sec;
|
|
* struct tm tm;
|
|
* time(&sec);
|
|
* localtime_r(&sec, &tm);
|
|
* strftime(b, sizeof(b), "%Y-%m-%dT%H:%M:%S%z", &tm); // ISO8601
|
|
* strftime(b, sizeof(b), "%a, %d %b %Y %H:%M:%S %Z", &tm); // RFC1123
|
|
*
|
|
* @return bytes copied excluding nul, or 0 on error
|
|
*/
|
|
size_t
|
|
strftime(char *s, size_t maxsize, const char *format, const struct tm *t)
|
|
{
|
|
char * p;
|
|
int saved_errno = errno;
|
|
enum warn warn = IN_NONE;
|
|
|
|
tzset();
|
|
p = strftime_fmt(format, t, s, s + maxsize, &warn);
|
|
if (!p) {
|
|
errno = EOVERFLOW;
|
|
return 0;
|
|
}
|
|
if (p == s + maxsize) {
|
|
errno = ERANGE;
|
|
return 0;
|
|
}
|
|
*p = '\0';
|
|
errno = saved_errno;
|
|
return p - s;
|
|
}
|
|
|
|
size_t
|
|
strftime_l(char *s, size_t maxsize, char const *format, struct tm const *t,
|
|
locale_t locale)
|
|
{
|
|
/* Just call strftime, as only the C locale is supported. */
|
|
return strftime(s, maxsize, format, t);
|
|
}
|