DESTDIR support for git/contrib/emacs
[gitweb.git] / date.c
diff --git a/date.c b/date.c
index 63f5a0919768112c0d3301e7afaa59edcce7da36..0ceccbe03401faa67836577b9bdbe139fe025dd5 100644 (file)
--- a/date.c
+++ b/date.c
@@ -4,8 +4,6 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 
-#include <time.h>
-
 #include "cache.h"
 
 static time_t my_mktime(struct tm *tm)
@@ -33,34 +31,105 @@ static const char *month_names[] = {
 };
 
 static const char *weekday_names[] = {
-       "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
+       "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"
  */
-const char *show_date(unsigned long time, int tz)
+static struct tm *time_to_tm(unsigned long time, int tz)
+{
+       time_t t = gm_time_t(time, tz);
+       return gmtime(&t);
+}
+
+const char *show_date(unsigned long time, int tz, enum date_mode mode)
 {
        struct tm *tm;
-       time_t t;
        static char timebuf[200];
-       int minutes;
 
-       minutes = tz < 0 ? -tz : tz;
-       minutes = (minutes / 100)*60 + (minutes % 100);
-       minutes = tz < 0 ? -minutes : minutes;
-       t = time + minutes * 60;
-       tm = gmtime(&t);
+       if (mode == DATE_RELATIVE) {
+               unsigned long diff;
+               struct timeval now;
+               gettimeofday(&now, NULL);
+               if (now.tv_sec < time)
+                       return "in the future";
+               diff = now.tv_sec - time;
+               if (diff < 90) {
+                       snprintf(timebuf, sizeof(timebuf), "%lu seconds ago", diff);
+                       return timebuf;
+               }
+               /* Turn it into minutes */
+               diff = (diff + 30) / 60;
+               if (diff < 90) {
+                       snprintf(timebuf, sizeof(timebuf), "%lu minutes ago", diff);
+                       return timebuf;
+               }
+               /* Turn it into hours */
+               diff = (diff + 30) / 60;
+               if (diff < 36) {
+                       snprintf(timebuf, sizeof(timebuf), "%lu hours ago", diff);
+                       return timebuf;
+               }
+               /* We deal with number of days from here on */
+               diff = (diff + 12) / 24;
+               if (diff < 14) {
+                       snprintf(timebuf, sizeof(timebuf), "%lu days ago", diff);
+                       return timebuf;
+               }
+               /* Say weeks for the past 10 weeks or so */
+               if (diff < 70) {
+                       snprintf(timebuf, sizeof(timebuf), "%lu weeks ago", (diff + 3) / 7);
+                       return timebuf;
+               }
+               /* Say months for the past 12 months or so */
+               if (diff < 360) {
+                       snprintf(timebuf, sizeof(timebuf), "%lu months ago", (diff + 15) / 30);
+                       return timebuf;
+               }
+               /* Else fall back on absolute format.. */
+       }
+
+       tm = time_to_tm(time, tz);
        if (!tm)
                return NULL;
-       sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+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, tz);
+       if (mode == DATE_SHORT)
+               sprintf(timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
+                               tm->tm_mon + 1, tm->tm_mday);
+       else
+               sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+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, tz);
+       return timebuf;
+}
+
+const char *show_rfc2822_date(unsigned long time, int tz)
+{
+       struct tm *tm;
+       static char timebuf[200];
+
+       tm = time_to_tm(time, tz);
+       if (!tm)
+               return NULL;
+       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);
        return timebuf;
 }
 
@@ -122,8 +191,6 @@ static const struct {
        { "IDLE", +12, 0, },    /* International Date Line East */
 };
 
-#define NR_TZ (sizeof(timezone_names) / sizeof(timezone_names[0]))
-       
 static int match_string(const char *date, const char *str)
 {
        int i = 0;
@@ -172,7 +239,7 @@ static int match_alpha(const char *date, struct tm *tm, int *offset)
                }
        }
 
-       for (i = 0; i < NR_TZ; i++) {
+       for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
                int match = match_string(date, timezone_names[i].name);
                if (match >= 3) {
                        int off = timezone_names[i].offset;
@@ -189,8 +256,12 @@ static int match_alpha(const char *date, struct tm *tm, int *offset)
        }
 
        if (match_string(date, "PM") == 2) {
-               if (tm->tm_hour > 0 && tm->tm_hour < 12)
-                       tm->tm_hour += 12;
+               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;
        }
 
@@ -198,26 +269,43 @@ static int match_alpha(const char *date, struct tm *tm, int *offset)
        return skip_alpha(date);
 }
 
-static int is_date(int year, int month, int day, struct tm *tm)
+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) {
-                       tm->tm_mon = month-1;
-                       tm->tm_mday = day;
-                       return 1;
+                       if (!now_tm)
+                               return 1;
+                       r->tm_year = now_tm->tm_year;
                }
-               if (year >= 1970 && year < 2100) {
-                       year -= 1900;
-               } else if (year > 70 && year < 100) {
-                       /* ok */
-               } else if (year < 38) {
-                       year += 100;
-               else
+               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;
 
-               tm->tm_mon = month-1;
-               tm->tm_mday = day;
-               tm->tm_year = year;
+               specified = my_mktime(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;
@@ -225,6 +313,9 @@ static int is_date(int year, int month, int day, struct tm *tm)
 
 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);
@@ -247,19 +338,33 @@ static int match_multi_number(unsigned long num, char c, const char *date, char
 
        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, tm))
+                       if (is_date(num, num2, num3, refuse_future, now, tm))
                                break;
                        /* yyyy-dd-mm? */
-                       if (is_date(num, num3, num2, tm))
+                       if (is_date(num, num3, num2, refuse_future, now, tm))
                                break;
                }
-               /* mm/dd/yy ? */
-               if (is_date(num3, num2, num, tm))
+               /* 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;
-               /* dd/mm/yy ? */
-               if (is_date(num3, num, num2, tm))
+               /* 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;
        }
@@ -289,10 +394,11 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt
        }
 
        /*
-        * Check for special formats: num[:-/]num[same]num
+        * Check for special formats: num[-.:/]num[same]num
         */
        switch (*end) {
        case ':':
+       case '.':
        case '/':
        case '-':
                if (isdigit(end[1])) {
@@ -314,7 +420,7 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt
 
        /* Four-digit year or a timezone? */
        if (n == 4) {
-               if (num <= 1200 && *offset == -1) {
+               if (num <= 1400 && *offset == -1) {
                        unsigned int minutes = num % 100;
                        unsigned int hours = num / 100;
                        *offset = hours*60 + minutes;
@@ -325,7 +431,7 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt
 
        /*
         * NOTE! We will give precedence to day-of-month over month or
-        * year numebers in the 1-12 range. So 05 is always "mday 5",
+        * 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".
@@ -460,3 +566,235 @@ void datestamp(char *buf, int bufsize)
 
        date_string(now, offset, buf, bufsize);
 }
+
+static void update_tm(struct tm *tm, unsigned long sec)
+{
+       time_t n = mktime(tm) - sec;
+       localtime_r(&n, tm);
+}
+
+static void date_yesterday(struct tm *tm, int *num)
+{
+       update_tm(tm, 24*60*60);
+}
+
+static void date_time(struct tm *tm, int hour)
+{
+       if (tm->tm_hour < hour)
+               date_yesterday(tm, NULL);
+       tm->tm_hour = hour;
+       tm->tm_min = 0;
+       tm->tm_sec = 0;
+}
+
+static void date_midnight(struct tm *tm, int *num)
+{
+       date_time(tm, 0);
+}
+
+static void date_noon(struct tm *tm, int *num)
+{
+       date_time(tm, 12);
+}
+
+static void date_tea(struct tm *tm, int *num)
+{
+       date_time(tm, 17);
+}
+
+static void date_pm(struct tm *tm, 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, 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 const struct special {
+       const char *name;
+       void (*fn)(struct tm *, int *);
+} special[] = {
+       { "yesterday", date_yesterday },
+       { "noon", date_noon },
+       { "midnight", date_midnight },
+       { "tea", date_tea },
+       { "PM", date_pm },
+       { "AM", date_am },
+       { 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, int *num)
+{
+       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;
+                       return end;
+               }
+       }
+
+       for (s = special; s->name; s++) {
+               int len = strlen(s->name);
+               if (match_string(date, s->name) == len) {
+                       s->fn(tm, num);
+                       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;
+                               return end;
+                       }
+               }
+               if (match_string(date, "last") == 4)
+                       *num = 1;
+               return end;
+       }
+
+       tl = typelen;
+       while (tl->type) {
+               int len = strlen(tl->type);
+               if (match_string(date, tl->type) >= len-1) {
+                       update_tm(tm, tl->length * *num);
+                       *num = 0;
+                       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, diff * 24 * 60 * 60);
+                       return end;
+               }
+       }
+
+       if (match_string(date, "months") >= 5) {
+               int n = tm->tm_mon - *num;
+               *num = 0;
+               while (n < 0) {
+                       n += 12;
+                       tm->tm_year--;
+               }
+               tm->tm_mon = n;
+               return end;
+       }
+
+       if (match_string(date, "years") >= 4) {
+               tm->tm_year -= *num;
+               *num = 0;
+               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;
+               }
+       }
+
+       *num = number;
+       return end;
+}
+
+unsigned long approxidate(const char *date)
+{
+       int number = 0;
+       struct tm tm, now;
+       struct timeval tv;
+       char buffer[50];
+
+       if (parse_date(date, buffer, sizeof(buffer)) > 0)
+               return strtoul(buffer, NULL, 10);
+
+       gettimeofday(&tv, NULL);
+       localtime_r(&tv.tv_sec, &tm);
+       now = tm;
+       for (;;) {
+               unsigned char c = *date;
+               if (!c)
+                       break;
+               date++;
+               if (isdigit(c)) {
+                       date = approxidate_digit(date-1, &tm, &number);
+                       continue;
+               }
+               if (isalpha(c))
+                       date = approxidate_alpha(date-1, &tm, &number);
+       }
+       if (number > 0 && number < 32)
+               tm.tm_mday = number;
+       if (tm.tm_mon > now.tm_mon && tm.tm_year == now.tm_year)
+               tm.tm_year--;
+       return mktime(&tm);
+}