diff --git a/COPYING b/COPYING new file mode 100644 --- /dev/null +++ b/COPYING @@ -0,0 +1,365 @@ +The date.c which forms the bulk of this library is ripped directly from +git, and so I have chosen to license the whole library the same as git, +with the contents of git's COPYING file reproduced below. + +---------------------------------------- + + Note that the only valid version of the GPL as far as this project + is concerned is _this_ particular version of the license (ie v2, not + v2.2 or v3.x or whatever), unless explicitly otherwise stated. + + HOWEVER, in order to allow a migration to GPLv3 if that seems like + a good idea, I also ask that people involved with the project make + their preferences known. In particular, if you trust me to make that + decision, you might note so in your copyright message, ie something + like + + This file is licensed under the GPL v2, or a later version + at the discretion of Linus. + + might avoid issues. But we can also just decide to synchronize and + contact all copyright holders on record if/when the occasion arises. + + Linus Torvalds + +---------------------------------------- + + GNU GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1989, 1991 Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. By contrast, the GNU General Public +License is intended to guarantee your freedom to share and change free +software--to make sure the software is free for all its users. This +General Public License applies to most of the Free Software +Foundation's software and to any other program whose authors commit to +using it. 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See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + + Gnomovision version 69, Copyright (C) year name of author + Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, the commands you use may +be called something other than `show w' and `show c'; they could even be +mouse-clicks or menu items--whatever suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the program + `Gnomovision' (which makes passes at compilers) written by James Hacker. + + , 1 April 1989 + Ty Coon, President of Vice + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. diff --git a/Data/Time/Git.hs b/Data/Time/Git.hs new file mode 100644 --- /dev/null +++ b/Data/Time/Git.hs @@ -0,0 +1,42 @@ +{-# LANGUAGE ForeignFunctionInterface #-} + +module Data.Time.Git (approxidate, approxidateUTC) where + +import Foreign +import Foreign.C.Types +import Foreign.C.String + +import Data.Time +import Data.Time.Clock.POSIX + +import qualified Data.ByteString as BS +import qualified Data.ByteString.UTF8 as BS (fromString) + +-- | Parse a date/time string and return Just a Unix timestamp. +-- Return Nothing if the string could not be interpreted. +-- If no timezone is in the string, the local timezone is used. +approxidate :: String -> Maybe Integer +approxidate = unsafePerformIO . io_approxidate_careful + +-- | The same as approxidate, but returns a UTCTime instead of a raw +-- timestamp. +approxidateUTC :: String -> Maybe UTCTime +approxidateUTC input = + fmap (posixSecondsToUTCTime . realToFrac) (approxidate input) + +foreign import ccall unsafe "date.c approxidate_careful" + c_approxidate_careful :: + CString -> Ptr CInt -> + IO CULong + +io_approxidate_careful :: String -> IO (Maybe Integer) +io_approxidate_careful input = + BS.useAsCString (BS.fromString input) (\c_input -> + alloca (\c_error_ret -> do + poke c_error_ret 0 + time <- c_approxidate_careful c_input c_error_ret + err <- peek c_error_ret + if err == 0 then return $ Just (toInteger time) else + return Nothing + ) + ) diff --git a/README b/README new file mode 100644 --- /dev/null +++ b/README @@ -0,0 +1,3 @@ +This library implements a simple, pure binding onto the date parsing +code from git. Why? Because it was the only reasonable implementation +of a generic date parser I could find. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,3 @@ +import Distribution.Simple + +main = defaultMain diff --git a/ext/date.c b/ext/date.c new file mode 100644 --- /dev/null +++ b/ext/date.c @@ -0,0 +1,1092 @@ +/* + * GIT - The information manager from hell + * + * Copyright (C) Linus Torvalds, 2005 + */ + +/* Add includes and some stuff from git to make this code independent + * -- Stephen Paul Weber */ + +#include +#include +#include +#include +#include +#include +#include + +#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0])) + +enum date_mode { + DATE_NORMAL = 0, + DATE_RELATIVE, + DATE_SHORT, + DATE_LOCAL, + DATE_ISO8601, + DATE_RFC2822, + DATE_RAW, + DATE_UNKNOWN +}; + +/* + * This is like mktime, but without normalization of tm_wday and tm_yday. + */ +static time_t tm_to_time_t(const struct tm *tm) +{ + static const int mdays[] = { + 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 + }; + int year = tm->tm_year - 70; + int month = tm->tm_mon; + int day = tm->tm_mday; + + 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; +} + +static const char *month_names[] = { + "January", "February", "March", "April", "May", "June", + "July", "August", "September", "October", "November", "December" +}; + +static const char *weekday_names[] = { + "Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays" +}; + +static time_t gm_time_t(unsigned long time, int tz) +{ + int minutes; + + minutes = tz < 0 ? -tz : tz; + minutes = (minutes / 100)*60 + (minutes % 100); + minutes = tz < 0 ? -minutes : minutes; + return time + minutes * 60; +} + +/* + * The "tz" thing is passed in as this strange "decimal parse of tz" + * thing, which means that tz -0100 is passed in as the integer -100, + * even though it means "sixty minutes off" + */ +static struct tm *time_to_tm(unsigned long time, int tz) +{ + time_t t = gm_time_t(time, tz); + return gmtime(&t); +} + +/* + * What value of "tz" was in effect back then at "time" in the + * local timezone? + */ +static int local_tzoffset(unsigned long time) +{ + time_t t, t_local; + struct tm tm; + int offset, eastwest; + + t = time; + localtime_r(&t, &tm); + t_local = tm_to_time_t(&tm); + + if (t_local < t) { + eastwest = -1; + offset = t - t_local; + } else { + eastwest = 1; + offset = t_local - t; + } + offset /= 60; /* in minutes */ + offset = (offset % 60) + ((offset / 60) * 100); + return offset * eastwest; +} + +const char *show_date_relative(unsigned long time, int tz, + const struct timeval *now, + char *timebuf, + size_t timebuf_size) +{ + unsigned long diff; + if (now->tv_sec < time) + return "in the future"; + diff = now->tv_sec - time; + if (diff < 90) { + snprintf(timebuf, timebuf_size, "%lu seconds ago", diff); + return timebuf; + } + /* Turn it into minutes */ + diff = (diff + 30) / 60; + if (diff < 90) { + snprintf(timebuf, timebuf_size, "%lu minutes ago", diff); + return timebuf; + } + /* Turn it into hours */ + diff = (diff + 30) / 60; + if (diff < 36) { + snprintf(timebuf, timebuf_size, "%lu hours ago", diff); + return timebuf; + } + /* We deal with number of days from here on */ + diff = (diff + 12) / 24; + if (diff < 14) { + snprintf(timebuf, timebuf_size, "%lu days ago", diff); + return timebuf; + } + /* Say weeks for the past 10 weeks or so */ + if (diff < 70) { + snprintf(timebuf, timebuf_size, "%lu weeks ago", (diff + 3) / 7); + return timebuf; + } + /* Say months for the past 12 months or so */ + if (diff < 365) { + snprintf(timebuf, timebuf_size, "%lu months ago", (diff + 15) / 30); + return timebuf; + } + /* Give years and months for 5 years or so */ + if (diff < 1825) { + unsigned long totalmonths = (diff * 12 * 2 + 365) / (365 * 2); + unsigned long years = totalmonths / 12; + unsigned long months = totalmonths % 12; + int n; + n = snprintf(timebuf, timebuf_size, "%lu year%s", + years, (years > 1 ? "s" : "")); + if (months) + snprintf(timebuf + n, timebuf_size - n, + ", %lu month%s ago", + months, (months > 1 ? "s" : "")); + else + snprintf(timebuf + n, timebuf_size - n, " ago"); + return timebuf; + } + /* Otherwise, just years. Centuries is probably overkill. */ + snprintf(timebuf, timebuf_size, "%lu years ago", (diff + 183) / 365); + return timebuf; +} + +const char *show_date(unsigned long time, int tz, enum date_mode mode) +{ + struct tm *tm; + static char timebuf[200]; + + if (mode == DATE_RAW) { + snprintf(timebuf, sizeof(timebuf), "%lu %+05d", time, tz); + return timebuf; + } + + if (mode == DATE_RELATIVE) { + struct timeval now; + gettimeofday(&now, NULL); + return show_date_relative(time, tz, &now, + timebuf, sizeof(timebuf)); + } + + if (mode == DATE_LOCAL) + tz = local_tzoffset(time); + + tm = time_to_tm(time, tz); + if (!tm) + return NULL; + if (mode == DATE_SHORT) + sprintf(timebuf, "%04d-%02d-%02d", tm->tm_year + 1900, + tm->tm_mon + 1, tm->tm_mday); + else if (mode == DATE_ISO8601) + sprintf(timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d", + tm->tm_year + 1900, + tm->tm_mon + 1, + tm->tm_mday, + tm->tm_hour, tm->tm_min, tm->tm_sec, + tz); + else if (mode == DATE_RFC2822) + sprintf(timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d", + weekday_names[tm->tm_wday], tm->tm_mday, + month_names[tm->tm_mon], tm->tm_year + 1900, + tm->tm_hour, tm->tm_min, tm->tm_sec, tz); + else + sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d", + weekday_names[tm->tm_wday], + month_names[tm->tm_mon], + tm->tm_mday, + tm->tm_hour, tm->tm_min, tm->tm_sec, + tm->tm_year + 1900, + (mode == DATE_LOCAL) ? 0 : ' ', + tz); + return timebuf; +} + +/* + * Check these. And note how it doesn't do the summer-time conversion. + * + * In my world, it's always summer, and things are probably a bit off + * in other ways too. + */ +static const struct { + const char *name; + int offset; + int dst; +} timezone_names[] = { + { "IDLW", -12, 0, }, /* International Date Line West */ + { "NT", -11, 0, }, /* Nome */ + { "CAT", -10, 0, }, /* Central Alaska */ + { "HST", -10, 0, }, /* Hawaii Standard */ + { "HDT", -10, 1, }, /* Hawaii Daylight */ + { "YST", -9, 0, }, /* Yukon Standard */ + { "YDT", -9, 1, }, /* Yukon Daylight */ + { "PST", -8, 0, }, /* Pacific Standard */ + { "PDT", -8, 1, }, /* Pacific Daylight */ + { "MST", -7, 0, }, /* Mountain Standard */ + { "MDT", -7, 1, }, /* Mountain Daylight */ + { "CST", -6, 0, }, /* Central Standard */ + { "CDT", -6, 1, }, /* Central Daylight */ + { "EST", -5, 0, }, /* Eastern Standard */ + { "EDT", -5, 1, }, /* Eastern Daylight */ + { "AST", -3, 0, }, /* Atlantic Standard */ + { "ADT", -3, 1, }, /* Atlantic Daylight */ + { "WAT", -1, 0, }, /* West Africa */ + + { "GMT", 0, 0, }, /* Greenwich Mean */ + { "UTC", 0, 0, }, /* Universal (Coordinated) */ + { "Z", 0, 0, }, /* Zulu, alias for UTC */ + + { "WET", 0, 0, }, /* Western European */ + { "BST", 0, 1, }, /* British Summer */ + { "CET", +1, 0, }, /* Central European */ + { "MET", +1, 0, }, /* Middle European */ + { "MEWT", +1, 0, }, /* Middle European Winter */ + { "MEST", +1, 1, }, /* Middle European Summer */ + { "CEST", +1, 1, }, /* Central European Summer */ + { "MESZ", +1, 1, }, /* Middle European Summer */ + { "FWT", +1, 0, }, /* French Winter */ + { "FST", +1, 1, }, /* French Summer */ + { "EET", +2, 0, }, /* Eastern Europe, USSR Zone 1 */ + { "EEST", +2, 1, }, /* Eastern European Daylight */ + { "WAST", +7, 0, }, /* West Australian Standard */ + { "WADT", +7, 1, }, /* West Australian Daylight */ + { "CCT", +8, 0, }, /* China Coast, USSR Zone 7 */ + { "JST", +9, 0, }, /* Japan Standard, USSR Zone 8 */ + { "EAST", +10, 0, }, /* Eastern Australian Standard */ + { "EADT", +10, 1, }, /* Eastern Australian Daylight */ + { "GST", +10, 0, }, /* Guam Standard, USSR Zone 9 */ + { "NZT", +12, 0, }, /* New Zealand */ + { "NZST", +12, 0, }, /* New Zealand Standard */ + { "NZDT", +12, 1, }, /* New Zealand Daylight */ + { "IDLE", +12, 0, }, /* International Date Line East */ +}; + +static int match_string(const char *date, const char *str) +{ + int i = 0; + + for (i = 0; *date; date++, str++, i++) { + if (*date == *str) + continue; + if (toupper(*date) == toupper(*str)) + continue; + if (!isalnum(*date)) + break; + return 0; + } + return i; +} + +static int skip_alpha(const char *date) +{ + int i = 0; + do { + i++; + } while (isalpha(date[i])); + return i; +} + +/* +* Parse month, weekday, or timezone name +*/ +static int match_alpha(const char *date, struct tm *tm, int *offset) +{ + int i; + + for (i = 0; i < 12; i++) { + int match = match_string(date, month_names[i]); + if (match >= 3) { + tm->tm_mon = i; + return match; + } + } + + for (i = 0; i < 7; i++) { + int match = match_string(date, weekday_names[i]); + if (match >= 3) { + tm->tm_wday = i; + return match; + } + } + + for (i = 0; i < ARRAY_SIZE(timezone_names); i++) { + int match = match_string(date, timezone_names[i].name); + if (match >= 3 || match == strlen(timezone_names[i].name)) { + int off = timezone_names[i].offset; + + /* This is bogus, but we like summer */ + off += timezone_names[i].dst; + + /* Only use the tz name offset if we don't have anything better */ + if (*offset == -1) + *offset = 60*off; + + return match; + } + } + + if (match_string(date, "PM") == 2) { + tm->tm_hour = (tm->tm_hour % 12) + 12; + return 2; + } + + if (match_string(date, "AM") == 2) { + tm->tm_hour = (tm->tm_hour % 12) + 0; + return 2; + } + + /* BAD CRAP */ + return skip_alpha(date); +} + +static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm) +{ + if (month > 0 && month < 13 && day > 0 && day < 32) { + struct tm check = *tm; + struct tm *r = (now_tm ? &check : tm); + time_t specified; + + r->tm_mon = month - 1; + r->tm_mday = day; + if (year == -1) { + if (!now_tm) + return 1; + r->tm_year = now_tm->tm_year; + } + else if (year >= 1970 && year < 2100) + r->tm_year = year - 1900; + else if (year > 70 && year < 100) + r->tm_year = year; + else if (year < 38) + r->tm_year = year + 100; + else + return 0; + if (!now_tm) + return 1; + + specified = tm_to_time_t(r); + + /* Be it commit time or author time, it does not make + * sense to specify timestamp way into the future. Make + * sure it is not later than ten days from now... + */ + if (now + 10*24*3600 < specified) + return 0; + tm->tm_mon = r->tm_mon; + tm->tm_mday = r->tm_mday; + if (year != -1) + tm->tm_year = r->tm_year; + return 1; + } + return 0; +} + +static int match_multi_number(unsigned long num, char c, const char *date, char *end, struct tm *tm) +{ + time_t now; + struct tm now_tm; + struct tm *refuse_future; + long num2, num3; + + num2 = strtol(end+1, &end, 10); + num3 = -1; + if (*end == c && isdigit(end[1])) + num3 = strtol(end+1, &end, 10); + + /* Time? Date? */ + switch (c) { + case ':': + if (num3 < 0) + num3 = 0; + if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) { + tm->tm_hour = num; + tm->tm_min = num2; + tm->tm_sec = num3; + break; + } + return 0; + + case '-': + case '/': + case '.': + now = time(NULL); + refuse_future = NULL; + if (gmtime_r(&now, &now_tm)) + refuse_future = &now_tm; + + if (num > 70) { + /* yyyy-mm-dd? */ + if (is_date(num, num2, num3, refuse_future, now, tm)) + break; + /* yyyy-dd-mm? */ + if (is_date(num, num3, num2, refuse_future, now, tm)) + break; + } + /* Our eastern European friends say dd.mm.yy[yy] + * is the norm there, so giving precedence to + * mm/dd/yy[yy] form only when separator is not '.' + */ + if (c != '.' && + is_date(num3, num, num2, refuse_future, now, tm)) + break; + /* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */ + if (is_date(num3, num2, num, refuse_future, now, tm)) + break; + /* Funny European mm.dd.yy */ + if (c == '.' && + is_date(num3, num, num2, refuse_future, now, tm)) + break; + return 0; + } + return end - date; +} + +/* + * Have we filled in any part of the time/date yet? + * We just do a binary 'and' to see if the sign bit + * is set in all the values. + */ +static inline int nodate(struct tm *tm) +{ + return (tm->tm_year & + tm->tm_mon & + tm->tm_mday & + tm->tm_hour & + tm->tm_min & + tm->tm_sec) < 0; +} + +/* + * We've seen a digit. Time? Year? Date? + */ +static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt) +{ + int n; + char *end; + unsigned long num; + + num = strtoul(date, &end, 10); + + /* + * Seconds since 1970? We trigger on that for any numbers with + * more than 8 digits. This is because we don't want to rule out + * numbers like 20070606 as a YYYYMMDD date. + */ + if (num >= 100000000 && nodate(tm)) { + time_t time = num; + if (gmtime_r(&time, tm)) { + *tm_gmt = 1; + return end - date; + } + } + + /* + * Check for special formats: num[-.:/]num[same]num + */ + switch (*end) { + case ':': + case '.': + case '/': + case '-': + if (isdigit(end[1])) { + int match = match_multi_number(num, *end, date, end, tm); + if (match) + return match; + } + } + + /* + * None of the special formats? Try to guess what + * the number meant. We use the number of digits + * to make a more educated guess.. + */ + n = 0; + do { + n++; + } while (isdigit(date[n])); + + /* Four-digit year or a timezone? */ + if (n == 4) { + if (num <= 1400 && *offset == -1) { + unsigned int minutes = num % 100; + unsigned int hours = num / 100; + *offset = hours*60 + minutes; + } else if (num > 1900 && num < 2100) + tm->tm_year = num - 1900; + return n; + } + + /* + * Ignore lots of numerals. We took care of 4-digit years above. + * Days or months must be one or two digits. + */ + if (n > 2) + return n; + + /* + * NOTE! We will give precedence to day-of-month over month or + * year numbers in the 1-12 range. So 05 is always "mday 5", + * unless we already have a mday.. + * + * IOW, 01 Apr 05 parses as "April 1st, 2005". + */ + if (num > 0 && num < 32 && tm->tm_mday < 0) { + tm->tm_mday = num; + return n; + } + + /* Two-digit year? */ + if (n == 2 && tm->tm_year < 0) { + if (num < 10 && tm->tm_mday >= 0) { + tm->tm_year = num + 100; + return n; + } + if (num >= 70) { + tm->tm_year = num; + return n; + } + } + + if (num > 0 && num < 13 && tm->tm_mon < 0) + tm->tm_mon = num-1; + + return n; +} + +static int match_tz(const char *date, int *offp) +{ + char *end; + int hour = strtoul(date + 1, &end, 10); + int n = end - (date + 1); + int min = 0; + + if (n == 4) { + /* hhmm */ + min = hour % 100; + hour = hour / 100; + } else if (n != 2) { + min = 99; /* random crap */ + } else if (*end == ':') { + /* hh:mm? */ + min = strtoul(end + 1, &end, 10); + if (end - (date + 1) != 5) + min = 99; /* random crap */ + } /* otherwise we parsed "hh" */ + + /* + * Don't accept any random crap. Even though some places have + * offset larger than 12 hours (e.g. Pacific/Kiritimati is at + * UTC+14), there is something wrong if hour part is much + * larger than that. We might also want to check that the + * minutes are divisible by 15 or something too. (Offset of + * Kathmandu, Nepal is UTC+5:45) + */ + if (min < 60 && hour < 24) { + int offset = hour * 60 + min; + if (*date == '-') + offset = -offset; + *offp = offset; + } + return end - date; +} + +static int date_string(unsigned long date, int offset, char *buf, int len) +{ + int sign = '+'; + + if (offset < 0) { + offset = -offset; + sign = '-'; + } + return snprintf(buf, len, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60); +} + +/* + * Parse a string like "0 +0000" as ancient timestamp near epoch, but + * only when it appears not as part of any other string. + */ +static int match_object_header_date(const char *date, unsigned long *timestamp, int *offset) +{ + char *end; + unsigned long stamp; + int ofs; + + if (*date < '0' || '9' <= *date) + return -1; + stamp = strtoul(date, &end, 10); + if (*end != ' ' || stamp == ULONG_MAX || (end[1] != '+' && end[1] != '-')) + return -1; + date = end + 2; + ofs = strtol(date, &end, 10); + if ((*end != '\0' && (*end != '\n')) || end != date + 4) + return -1; + ofs = (ofs / 100) * 60 + (ofs % 100); + if (date[-1] == '-') + ofs = -ofs; + *timestamp = stamp; + *offset = ofs; + return 0; +} + +/* Gr. strptime is crap for this; it doesn't have a way to require RFC2822 + (i.e. English) day/month names, and it doesn't work correctly with %z. */ +int parse_date_basic(const char *date, unsigned long *timestamp, int *offset) +{ + struct tm tm; + int tm_gmt; + unsigned long dummy_timestamp; + int dummy_offset; + + if (!timestamp) + timestamp = &dummy_timestamp; + if (!offset) + offset = &dummy_offset; + + memset(&tm, 0, sizeof(tm)); + tm.tm_year = -1; + tm.tm_mon = -1; + tm.tm_mday = -1; + tm.tm_isdst = -1; + tm.tm_hour = -1; + tm.tm_min = -1; + tm.tm_sec = -1; + *offset = -1; + tm_gmt = 0; + + if (*date == '@' && + !match_object_header_date(date + 1, timestamp, offset)) + return 0; /* success */ + for (;;) { + int match = 0; + unsigned char c = *date; + + /* Stop at end of string or newline */ + if (!c || c == '\n') + break; + + if (isalpha(c)) + match = match_alpha(date, &tm, offset); + else if (isdigit(c)) + match = match_digit(date, &tm, offset, &tm_gmt); + else if ((c == '-' || c == '+') && isdigit(date[1])) + match = match_tz(date, offset); + + if (!match) { + /* BAD CRAP */ + match = 1; + } + + date += match; + } + + /* mktime uses local timezone */ + *timestamp = tm_to_time_t(&tm); + if (*offset == -1) + *offset = ((time_t)*timestamp - mktime(&tm)) / 60; + + if (*timestamp == -1) + return -1; + + if (!tm_gmt) + *timestamp -= *offset * 60; + return 0; /* success */ +} + +int parse_date(const char *date, char *result, int maxlen) +{ + unsigned long timestamp; + int offset; + if (parse_date_basic(date, ×tamp, &offset)) + return -1; + return date_string(timestamp, offset, result, maxlen); +} + +enum date_mode parse_date_format(const char *format) +{ + if (!strcmp(format, "relative")) + return DATE_RELATIVE; + else if (!strcmp(format, "iso8601") || + !strcmp(format, "iso")) + return DATE_ISO8601; + else if (!strcmp(format, "rfc2822") || + !strcmp(format, "rfc")) + return DATE_RFC2822; + else if (!strcmp(format, "short")) + return DATE_SHORT; + else if (!strcmp(format, "local")) + return DATE_LOCAL; + else if (!strcmp(format, "default")) + return DATE_NORMAL; + else if (!strcmp(format, "raw")) + return DATE_RAW; + else + return DATE_UNKNOWN; +} + +void datestamp(char *buf, int bufsize) +{ + time_t now; + int offset; + + time(&now); + + offset = tm_to_time_t(localtime(&now)) - now; + offset /= 60; + + date_string(now, offset, buf, bufsize); +} + +/* + * Relative time update (eg "2 days ago"). If we haven't set the time + * yet, we need to set it from current time. + */ +static unsigned long update_tm(struct tm *tm, struct tm *now, unsigned long sec) +{ + time_t n; + + if (tm->tm_mday < 0) + tm->tm_mday = now->tm_mday; + if (tm->tm_mon < 0) + tm->tm_mon = now->tm_mon; + if (tm->tm_year < 0) { + tm->tm_year = now->tm_year; + if (tm->tm_mon > now->tm_mon) + tm->tm_year--; + } + + n = mktime(tm) - sec; + localtime_r(&n, tm); + return n; +} + +static void date_now(struct tm *tm, struct tm *now, int *num) +{ + update_tm(tm, now, 0); +} + +static void date_yesterday(struct tm *tm, struct tm *now, int *num) +{ + update_tm(tm, now, 24*60*60); +} + +static void date_time(struct tm *tm, struct tm *now, int hour) +{ + if (tm->tm_hour < hour) + date_yesterday(tm, now, NULL); + tm->tm_hour = hour; + tm->tm_min = 0; + tm->tm_sec = 0; +} + +static void date_midnight(struct tm *tm, struct tm *now, int *num) +{ + date_time(tm, now, 0); +} + +static void date_noon(struct tm *tm, struct tm *now, int *num) +{ + date_time(tm, now, 12); +} + +static void date_tea(struct tm *tm, struct tm *now, int *num) +{ + date_time(tm, now, 17); +} + +static void date_pm(struct tm *tm, struct tm *now, int *num) +{ + int hour, n = *num; + *num = 0; + + hour = tm->tm_hour; + if (n) { + hour = n; + tm->tm_min = 0; + tm->tm_sec = 0; + } + tm->tm_hour = (hour % 12) + 12; +} + +static void date_am(struct tm *tm, struct tm *now, int *num) +{ + int hour, n = *num; + *num = 0; + + hour = tm->tm_hour; + if (n) { + hour = n; + tm->tm_min = 0; + tm->tm_sec = 0; + } + tm->tm_hour = (hour % 12); +} + +static void date_never(struct tm *tm, struct tm *now, int *num) +{ + time_t n = 0; + localtime_r(&n, tm); +} + +static const struct special { + const char *name; + void (*fn)(struct tm *, struct tm *, int *); +} special[] = { + { "yesterday", date_yesterday }, + { "noon", date_noon }, + { "midnight", date_midnight }, + { "tea", date_tea }, + { "PM", date_pm }, + { "AM", date_am }, + { "never", date_never }, + { "now", date_now }, + { NULL } +}; + +static const char *number_name[] = { + "zero", "one", "two", "three", "four", + "five", "six", "seven", "eight", "nine", "ten", +}; + +static const struct typelen { + const char *type; + int length; +} typelen[] = { + { "seconds", 1 }, + { "minutes", 60 }, + { "hours", 60*60 }, + { "days", 24*60*60 }, + { "weeks", 7*24*60*60 }, + { NULL } +}; + +static const char *approxidate_alpha(const char *date, struct tm *tm, struct tm *now, int *num, int *touched) +{ + const struct typelen *tl; + const struct special *s; + const char *end = date; + int i; + + while (isalpha(*++end)); + ; + + for (i = 0; i < 12; i++) { + int match = match_string(date, month_names[i]); + if (match >= 3) { + tm->tm_mon = i; + *touched = 1; + return end; + } + } + + for (s = special; s->name; s++) { + int len = strlen(s->name); + if (match_string(date, s->name) == len) { + s->fn(tm, now, num); + *touched = 1; + return end; + } + } + + if (!*num) { + for (i = 1; i < 11; i++) { + int len = strlen(number_name[i]); + if (match_string(date, number_name[i]) == len) { + *num = i; + *touched = 1; + return end; + } + } + if (match_string(date, "last") == 4) { + *num = 1; + *touched = 1; + } + return end; + } + + tl = typelen; + while (tl->type) { + int len = strlen(tl->type); + if (match_string(date, tl->type) >= len-1) { + update_tm(tm, now, tl->length * *num); + *num = 0; + *touched = 1; + return end; + } + tl++; + } + + for (i = 0; i < 7; i++) { + int match = match_string(date, weekday_names[i]); + if (match >= 3) { + int diff, n = *num -1; + *num = 0; + + diff = tm->tm_wday - i; + if (diff <= 0) + n++; + diff += 7*n; + + update_tm(tm, now, diff * 24 * 60 * 60); + *touched = 1; + return end; + } + } + + if (match_string(date, "months") >= 5) { + int n; + update_tm(tm, now, 0); /* fill in date fields if needed */ + n = tm->tm_mon - *num; + *num = 0; + while (n < 0) { + n += 12; + tm->tm_year--; + } + tm->tm_mon = n; + *touched = 1; + return end; + } + + if (match_string(date, "years") >= 4) { + update_tm(tm, now, 0); /* fill in date fields if needed */ + tm->tm_year -= *num; + *num = 0; + *touched = 1; + return end; + } + + return end; +} + +static const char *approxidate_digit(const char *date, struct tm *tm, int *num) +{ + char *end; + unsigned long number = strtoul(date, &end, 10); + + switch (*end) { + case ':': + case '.': + case '/': + case '-': + if (isdigit(end[1])) { + int match = match_multi_number(number, *end, date, end, tm); + if (match) + return date + match; + } + } + + /* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */ + if (date[0] != '0' || end - date <= 2) + *num = number; + return end; +} + +/* + * Do we have a pending number at the end, or when + * we see a new one? Let's assume it's a month day, + * as in "Dec 6, 1992" + */ +static void pending_number(struct tm *tm, int *num) +{ + int number = *num; + + if (number) { + *num = 0; + if (tm->tm_mday < 0 && number < 32) + tm->tm_mday = number; + else if (tm->tm_mon < 0 && number < 13) + tm->tm_mon = number-1; + else if (tm->tm_year < 0) { + if (number > 1969 && number < 2100) + tm->tm_year = number - 1900; + else if (number > 69 && number < 100) + tm->tm_year = number; + else if (number < 38) + tm->tm_year = 100 + number; + /* We screw up for number = 00 ? */ + } + } +} + +static unsigned long approxidate_str(const char *date, + const struct timeval *tv, + int *error_ret) +{ + int number = 0; + int touched = 0; + struct tm tm, now; + time_t time_sec; + + time_sec = tv->tv_sec; + localtime_r(&time_sec, &tm); + now = tm; + + tm.tm_year = -1; + tm.tm_mon = -1; + tm.tm_mday = -1; + + for (;;) { + unsigned char c = *date; + if (!c) + break; + date++; + if (isdigit(c)) { + pending_number(&tm, &number); + date = approxidate_digit(date-1, &tm, &number); + touched = 1; + continue; + } + if (isalpha(c)) + date = approxidate_alpha(date-1, &tm, &now, &number, &touched); + } + pending_number(&tm, &number); + if (!touched) + *error_ret = 1; + return update_tm(&tm, &now, 0); +} + +unsigned long approxidate_relative(const char *date, const struct timeval *tv) +{ + unsigned long timestamp; + int offset; + int errors = 0; + + if (!parse_date_basic(date, ×tamp, &offset)) + return timestamp; + return approxidate_str(date, tv, &errors); +} + +unsigned long approxidate_careful(const char *date, int *error_ret) +{ + struct timeval tv; + unsigned long timestamp; + int offset; + int dummy = 0; + if (!error_ret) + error_ret = &dummy; + + if (!parse_date_basic(date, ×tamp, &offset)) { + *error_ret = 0; + return timestamp; + } + + gettimeofday(&tv, NULL); + return approxidate_str(date, &tv, error_ret); +} diff --git a/git-date.cabal b/git-date.cabal new file mode 100644 --- /dev/null +++ b/git-date.cabal @@ -0,0 +1,40 @@ +name: git-date +version: 0.1 +cabal-version: >= 1.8 +license: GPL-2 +license-file: COPYING +category: Data +copyright: © 2012 Stephen Paul Weber +author: Stephen Paul Weber +maintainer: Stephen Paul Weber +stability: experimental +tested-with: GHC == 7.0.3 +synopsis: Bindings to the date parsing from Git. +homepage: https://github.com/singpolyma/git-date-haskell +bug-reports: https://github.com/singpolyma/git-date-haskell/issues +build-type: Simple +description: + This library implements a simple, pure binding onto the date parsing + code from git. Why? Because it was the only reasonable implementation + of a generic date parser I could find. + +extra-source-files: + README, + ext/date.c + +library + c-sources: ext/date.c + include-dirs: ext + + exposed-modules: + Data.Time.Git + + build-depends: + base == 4.*, + bytestring, + utf8-string, + time + +source-repository head + type: git + location: git://github.com/singpolyma/git-date-haskell.git