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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
commit | 6eb9c5a5657d1fe77b55cc261450f3538d35a94d (patch) | |
tree | 657d8194422a5daccecfd42d654b8a245ef7b4c8 /src/timezone/strftime.c | |
parent | Initial commit. (diff) | |
download | postgresql-13-upstream.tar.xz postgresql-13-upstream.zip |
Adding upstream version 13.4.upstream/13.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/timezone/strftime.c')
-rw-r--r-- | src/timezone/strftime.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/src/timezone/strftime.c b/src/timezone/strftime.c new file mode 100644 index 0000000..dd6c7db --- /dev/null +++ b/src/timezone/strftime.c @@ -0,0 +1,571 @@ +/* Convert a broken-down timestamp to a string. */ + +/* + * Copyright 1989 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Based on the UCB version with the copyright notice appearing above. + * + * This is ANSIish only when "multibyte character == plain character". + * + * IDENTIFICATION + * src/timezone/strftime.c + */ + +#include "postgres.h" + +#include <fcntl.h> + +#include "private.h" + + +struct lc_time_T +{ + const char *mon[MONSPERYEAR]; + const char *month[MONSPERYEAR]; + const char *wday[DAYSPERWEEK]; + const char *weekday[DAYSPERWEEK]; + const char *X_fmt; + const char *x_fmt; + const char *c_fmt; + const char *am; + const char *pm; + const char *date_fmt; +}; + +#define Locale (&C_time_locale) + +static const struct lc_time_T C_time_locale = { + { + "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" + }, { + "January", "February", "March", "April", "May", "June", + "July", "August", "September", "October", "November", "December" + }, { + "Sun", "Mon", "Tue", "Wed", + "Thu", "Fri", "Sat" + }, { + "Sunday", "Monday", "Tuesday", "Wednesday", + "Thursday", "Friday", "Saturday" + }, + + /* X_fmt */ + "%H:%M:%S", + + /* + * x_fmt + * + * C99 and later require this format. Using just numbers (as here) makes + * Quakers happier; it's also compatible with SVR4. + */ + "%m/%d/%y", + + /* + * c_fmt + * + * C99 and later require this format. Previously this code used "%D %X", + * but we now conform to C99. Note that "%a %b %d %H:%M:%S %Y" is used by + * Solaris 2.3. + */ + "%a %b %e %T %Y", + + /* am */ + "AM", + + /* pm */ + "PM", + + /* date_fmt */ + "%a %b %e %H:%M:%S %Z %Y" +}; + +enum warn +{ + IN_NONE, IN_SOME, IN_THIS, IN_ALL +}; + +static char *_add(const char *, char *, const char *); +static char *_conv(int, const char *, char *, const char *); +static char *_fmt(const char *, const struct pg_tm *, char *, const char *, + enum warn *); +static char *_yconv(int, int, bool, bool, char *, char const *); + + +/* + * Convert timestamp t to string s, a caller-allocated buffer of size maxsize, + * using the given format pattern. + * + * See also timestamptz_to_str. + */ +size_t +pg_strftime(char *s, size_t maxsize, const char *format, const struct pg_tm *t) +{ + char *p; + int saved_errno = errno; + enum warn warn = IN_NONE; + + p = _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; +} + +static char * +_fmt(const char *format, const struct pg_tm *t, char *pt, + const char *ptlim, enum warn *warnp) +{ + for (; *format; ++format) + { + if (*format == '%') + { + label: + switch (*++format) + { + case '\0': + --format; + break; + case 'A': + pt = _add((t->tm_wday < 0 || + t->tm_wday >= DAYSPERWEEK) ? + "?" : Locale->weekday[t->tm_wday], + pt, ptlim); + continue; + case 'a': + pt = _add((t->tm_wday < 0 || + t->tm_wday >= DAYSPERWEEK) ? + "?" : Locale->wday[t->tm_wday], + pt, ptlim); + continue; + case 'B': + pt = _add((t->tm_mon < 0 || + t->tm_mon >= MONSPERYEAR) ? + "?" : Locale->month[t->tm_mon], + pt, ptlim); + continue; + case 'b': + case 'h': + pt = _add((t->tm_mon < 0 || + t->tm_mon >= MONSPERYEAR) ? + "?" : Locale->mon[t->tm_mon], + pt, ptlim); + continue; + case 'C': + + /* + * %C used to do a... _fmt("%a %b %e %X %Y", t); + * ...whereas now POSIX 1003.2 calls for something + * completely different. (ado, 1993-05-24) + */ + pt = _yconv(t->tm_year, TM_YEAR_BASE, + true, false, pt, ptlim); + continue; + case 'c': + { + enum warn warn2 = IN_SOME; + + pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2); + if (warn2 == IN_ALL) + warn2 = IN_THIS; + if (warn2 > *warnp) + *warnp = warn2; + } + continue; + case 'D': + pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); + continue; + case 'd': + pt = _conv(t->tm_mday, "%02d", pt, ptlim); + continue; + case 'E': + case 'O': + + /* + * Locale modifiers of C99 and later. The sequences %Ec + * %EC %Ex %EX %Ey %EY %Od %oe %OH %OI %Om %OM %OS %Ou %OU + * %OV %Ow %OW %Oy are supposed to provide alternative + * representations. + */ + goto label; + case 'e': + pt = _conv(t->tm_mday, "%2d", pt, ptlim); + continue; + case 'F': + pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); + continue; + case 'H': + pt = _conv(t->tm_hour, "%02d", pt, ptlim); + continue; + case 'I': + pt = _conv((t->tm_hour % 12) ? + (t->tm_hour % 12) : 12, + "%02d", pt, ptlim); + continue; + case 'j': + pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim); + continue; + case 'k': + + /* + * This used to be... _conv(t->tm_hour % 12 ? t->tm_hour % + * 12 : 12, 2, ' '); ...and has been changed to the below + * to match SunOS 4.1.1 and Arnold Robbins' strftime + * version 3.0. That is, "%k" and "%l" have been swapped. + * (ado, 1993-05-24) + */ + pt = _conv(t->tm_hour, "%2d", pt, ptlim); + continue; +#ifdef KITCHEN_SINK + case 'K': + + /* + * After all this time, still unclaimed! + */ + pt = _add("kitchen sink", pt, ptlim); + continue; +#endif /* defined KITCHEN_SINK */ + case 'l': + + /* + * This used to be... _conv(t->tm_hour, 2, ' '); ...and + * has been changed to the below to match SunOS 4.1.1 and + * Arnold Robbin's strftime version 3.0. That is, "%k" and + * "%l" have been swapped. (ado, 1993-05-24) + */ + pt = _conv((t->tm_hour % 12) ? + (t->tm_hour % 12) : 12, + "%2d", pt, ptlim); + continue; + case 'M': + pt = _conv(t->tm_min, "%02d", pt, ptlim); + continue; + case 'm': + pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim); + continue; + case 'n': + pt = _add("\n", pt, ptlim); + continue; + case 'p': + pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? + Locale->pm : + Locale->am, + pt, ptlim); + continue; + case 'R': + pt = _fmt("%H:%M", t, pt, ptlim, warnp); + continue; + case 'r': + pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); + continue; + case 'S': + pt = _conv(t->tm_sec, "%02d", pt, ptlim); + continue; + case 'T': + pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); + continue; + case 't': + pt = _add("\t", pt, ptlim); + continue; + case 'U': + pt = _conv((t->tm_yday + DAYSPERWEEK - + t->tm_wday) / DAYSPERWEEK, + "%02d", pt, ptlim); + continue; + case 'u': + + /* + * From Arnold Robbins' strftime version 3.0: "ISO 8601: + * Weekday as a decimal number [1 (Monday) - 7]" (ado, + * 1993-05-24) + */ + pt = _conv((t->tm_wday == 0) ? + DAYSPERWEEK : t->tm_wday, + "%d", pt, ptlim); + continue; + case 'V': /* ISO 8601 week number */ + case 'G': /* ISO 8601 year (four digits) */ + case 'g': /* ISO 8601 year (two digits) */ +/* + * From Arnold Robbins' strftime version 3.0: "the week number of the + * year (the first Monday as the first day of week 1) as a decimal number + * (01-53)." + * (ado, 1993-05-24) + * + * From <https://www.cl.cam.ac.uk/~mgk25/iso-time.html> by Markus Kuhn: + * "Week 01 of a year is per definition the first week which has the + * Thursday in this year, which is equivalent to the week which contains + * the fourth day of January. In other words, the first week of a new year + * is the week which has the majority of its days in the new year. Week 01 + * might also contain days from the previous year and the week before week + * 01 of a year is the last week (52 or 53) of the previous year even if + * it contains days from the new year. A week starts with Monday (day 1) + * and ends with Sunday (day 7). For example, the first week of the year + * 1997 lasts from 1996-12-30 to 1997-01-05..." + * (ado, 1996-01-02) + */ + { + int year; + int base; + int yday; + int wday; + int w; + + year = t->tm_year; + base = TM_YEAR_BASE; + yday = t->tm_yday; + wday = t->tm_wday; + for (;;) + { + int len; + int bot; + int top; + + len = isleap_sum(year, base) ? + DAYSPERLYEAR : + DAYSPERNYEAR; + + /* + * What yday (-3 ... 3) does the ISO year begin + * on? + */ + bot = ((yday + 11 - wday) % + DAYSPERWEEK) - 3; + + /* + * What yday does the NEXT ISO year begin on? + */ + top = bot - + (len % DAYSPERWEEK); + if (top < -3) + top += DAYSPERWEEK; + top += len; + if (yday >= top) + { + ++base; + w = 1; + break; + } + if (yday >= bot) + { + w = 1 + ((yday - bot) / + DAYSPERWEEK); + break; + } + --base; + yday += isleap_sum(year, base) ? + DAYSPERLYEAR : + DAYSPERNYEAR; + } + if (*format == 'V') + pt = _conv(w, "%02d", + pt, ptlim); + else if (*format == 'g') + { + *warnp = IN_ALL; + pt = _yconv(year, base, + false, true, + pt, ptlim); + } + else + pt = _yconv(year, base, + true, true, + pt, ptlim); + } + continue; + case 'v': + + /* + * From Arnold Robbins' strftime version 3.0: "date as + * dd-bbb-YYYY" (ado, 1993-05-24) + */ + pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); + continue; + case 'W': + pt = _conv((t->tm_yday + DAYSPERWEEK - + (t->tm_wday ? + (t->tm_wday - 1) : + (DAYSPERWEEK - 1))) / DAYSPERWEEK, + "%02d", pt, ptlim); + continue; + case 'w': + pt = _conv(t->tm_wday, "%d", pt, ptlim); + continue; + case 'X': + pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp); + continue; + case 'x': + { + enum warn warn2 = IN_SOME; + + pt = _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 = _yconv(t->tm_year, TM_YEAR_BASE, + false, true, + pt, ptlim); + continue; + case 'Y': + pt = _yconv(t->tm_year, TM_YEAR_BASE, + true, true, + pt, ptlim); + continue; + case 'Z': + if (t->tm_zone != NULL) + pt = _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; + + if (t->tm_isdst < 0) + continue; + diff = t->tm_gmtoff; + negative = diff < 0; + if (diff == 0) + { + if (t->tm_zone != NULL) + negative = t->tm_zone[0] == '-'; + } + if (negative) + { + sign = "-"; + diff = -diff; + } + else + sign = "+"; + pt = _add(sign, pt, ptlim); + diff /= SECSPERMIN; + diff = (diff / MINSPERHOUR) * 100 + + (diff % MINSPERHOUR); + pt = _conv(diff, "%04d", pt, ptlim); + } + continue; + case '+': + pt = _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; +} + +static char * +_conv(int n, const char *format, char *pt, const char *ptlim) +{ + char buf[INT_STRLEN_MAXIMUM(int) + 1]; + + sprintf(buf, format, n); + return _add(buf, pt, ptlim); +} + +static char * +_add(const char *str, char *pt, const char *ptlim) +{ + while (pt < ptlim && (*pt = *str++) != '\0') + ++pt; + return pt; +} + +/* + * POSIX and the C Standard are unclear or inconsistent about + * what %C and %y do if the year is negative or exceeds 9999. + * Use the convention that %C concatenated with %y yields the + * same output as %Y, and that %Y contains at least 4 bytes, + * with more only if necessary. + */ + +static char * +_yconv(int a, int b, bool convert_top, bool convert_yy, + char *pt, const char *ptlim) +{ + int lead; + int trail; + +#define DIVISOR 100 + trail = a % DIVISOR + b % DIVISOR; + lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; + trail %= DIVISOR; + if (trail < 0 && lead > 0) + { + trail += DIVISOR; + --lead; + } + else if (lead < 0 && trail > 0) + { + trail -= DIVISOR; + ++lead; + } + if (convert_top) + { + if (lead == 0 && trail < 0) + pt = _add("-0", pt, ptlim); + else + pt = _conv(lead, "%02d", pt, ptlim); + } + if (convert_yy) + pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim); + return pt; +} |