GIT 0.99.9l aka 1.0rc4
[gitweb.git] / date.c
diff --git a/date.c b/date.c
index 0022bf2179e883929c49054d69aec9f3f6b0ca83..3e11500eda5e75a7ec354441fe4a24fd5ebf8bbc 100644 (file)
--- a/date.c
+++ b/date.c
@@ -4,11 +4,10 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
 #include <time.h>
+#include <sys/time.h>
+
+#include "cache.h"
 
 static time_t my_mktime(struct tm *tm)
 {
@@ -35,9 +34,37 @@ static const char *month_names[] = {
 };
 
 static const char *weekday_names[] = {
-       "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
+       "Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
 };
 
+/*
+ * 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)
+{
+       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 (!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);
+       return timebuf;
+}
+
 /*
  * Check these. And note how it doesn't do the summer-time conversion.
  *
@@ -82,6 +109,7 @@ static const struct {
        { "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 */
@@ -113,6 +141,15 @@ static int match_string(const char *date, const char *str)
        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
 */
@@ -144,109 +181,228 @@ static int match_alpha(const char *date, struct tm *tm, int *offset)
                        /* This is bogus, but we like summer */
                        off += timezone_names[i].dst;
 
-                       *offset = 60*off;
+                       /* 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) {
+               if (tm->tm_hour > 0 && tm->tm_hour < 12)
+                       tm->tm_hour += 12;
+               return 2;
+       }
+
        /* BAD CRAP */
+       return skip_alpha(date);
+}
+
+static int is_date(int year, int month, int day, struct tm *tm)
+{
+       if (month > 0 && month < 13 && day > 0 && day < 32) {
+               if (year == -1) {
+                       tm->tm_mon = month-1;
+                       tm->tm_mday = day;
+                       return 1;
+               }
+               if (year >= 1970 && year < 2100) {
+                       year -= 1900;
+               } else if (year > 70 && year < 100) {
+                       /* ok */
+               } else if (year < 38) {
+                       year += 100;
+               } else
+                       return 0;
+
+               tm->tm_mon = month-1;
+               tm->tm_mday = day;
+               tm->tm_year = year;
+               return 1;
+       }
        return 0;
 }
 
-static int match_digit(char *date, struct tm *tm, int *offset)
+static int match_multi_number(unsigned long num, char c, const char *date, char *end, struct tm *tm)
+{
+       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 '/':
+               if (num > 70) {
+                       /* yyyy-mm-dd? */
+                       if (is_date(num, num2, num3, tm))
+                               break;
+                       /* yyyy-dd-mm? */
+                       if (is_date(num, num3, num2, tm))
+                               break;
+               }
+               /* mm/dd/yy ? */
+               if (is_date(num3, num2, num, tm))
+                       break;
+               /* dd/mm/yy ? */
+               if (is_date(num3, num, num2, tm))
+                       break;
+               return 0;
+       }
+       return end - date;
+}
+
+/*
+ * We've seen a digit. Time? Year? Date? 
+ */
+static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
 {
-       char *end, c;
-       unsigned long num, num2, num3;
+       int n;
+       char *end;
+       unsigned long num;
 
        num = strtoul(date, &end, 10);
 
-       /* Time? num:num[:num] */
-       if (num < 24 && end[0] == ':' && isdigit(end[1])) {
-               tm->tm_hour = num;
-               num = strtoul(end+1, &end, 10);
-               if (num < 60) {
-                       tm->tm_min = num;
-                       if (end[0] == ':' && isdigit(end[1])) {
-                               num = strtoul(end+1, &end, 10);
-                               if (num < 61)
-                                       tm->tm_sec = num;
-                       }
+       /*
+        * Seconds since 1970? We trigger on that for anything after Jan 1, 2000
+        */
+       if (num > 946684800) {
+               time_t time = num;
+               if (gmtime_r(&time, tm)) {
+                       *tm_gmt = 1;
+                       return end - date;
                }
-               return end - date;
        }
 
-       /* Year? Day of month? Numeric date-string?*/
-       c = *end;
-       switch (c) {
-       default:
-               if (num > 0 && num < 32) {
-                       tm->tm_mday = num;
-                       break;
+       /*
+        * Check for special formats: num[:-/]num[same]num
+        */
+       switch (*end) {
+       case ':':
+       case '/':
+       case '-':
+               if (isdigit(end[1])) {
+                       int match = match_multi_number(num, *end, date, end, tm);
+                       if (match)
+                               return match;
                }
-               if (num > 1900) {
+       }
+
+       /*
+        * 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 <= 1200 && *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;
-                       break;
+               return n;
+       }
+
+       /*
+        * 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",
+        * 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) {
+               if (num >= 70) {
                        tm->tm_year = num;
-                       break;
+                       return n;
                }
-               break;
+       }
 
-       case '-':
-       case '/':
-               if (num && num < 32 && isdigit(end[1])) {
-                       num2 = strtoul(end+1, &end, 10);
-                       if (!num2 || num2 > 31)
-                               break;
-                       if (num > 12) {
-                               if (num2 > 12)
-                                       break;
-                               num3 = num;
-                               num  = num2;
-                               num2 = num3;
-                       }
-                       tm->tm_mon = num - 1;
-                       tm->tm_mday = num2;
-                       if (*end == c && isdigit(end[1])) {
-                               num3 = strtoul(end+1, &end, 10);
-                               if (num3 > 1900)
-                                       num3 -= 1900;
-                               else if (num3 < 38)
-                                       num3 += 100;
-                               tm->tm_year = num3;
-                       }
-                       break;
-               }
+       if (num > 0 && num < 32) {
+               tm->tm_mday = num;
+       } else if (num > 1900) {
+               tm->tm_year = num - 1900;
+       } else if (num > 70) {
+               tm->tm_year = num;
+       } else if (num > 0 && num < 13) {
+               tm->tm_mon = num-1;
        }
                
-       return end - date;
-                       
+       return n;
 }
 
-static int match_tz(char *date, int *offp)
+static int match_tz(const char *date, int *offp)
 {
        char *end;
        int offset = strtoul(date+1, &end, 10);
        int min, hour;
+       int n = end - date - 1;
 
        min = offset % 100;
        hour = offset / 100;
 
-       offset = hour*60+min;
-       if (*date == '-')
-               offset = -offset;
-
-       *offp = offset;
+       /*
+        * Don't accept any random crap.. At least 3 digits, and
+        * a valid minute. We might want to check that the minutes
+        * are divisible by 30 or something too.
+        */
+       if (min < 60 && n > 2) {
+               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);
+}
+
 /* 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. */
-void parse_date(char *date, char *result, int maxlen)
+int parse_date(const char *date, char *result, int maxlen)
 {
        struct tm tm;
-       int offset;
+       int offset, tm_gmt;
        time_t then;
 
        memset(&tm, 0, sizeof(tm));
@@ -255,6 +411,7 @@ void parse_date(char *date, char *result, int maxlen)
        tm.tm_mday = -1;
        tm.tm_isdst = -1;
        offset = -1;
+       tm_gmt = 0;
 
        for (;;) {
                int match = 0;
@@ -267,7 +424,7 @@ void parse_date(char *date, char *result, int maxlen)
                if (isalpha(c))
                        match = match_alpha(date, &tm, &offset);
                else if (isdigit(c))
-                       match = match_digit(date, &tm, &offset);
+                       match = match_digit(date, &tm, &offset, &tm_gmt);
                else if ((c == '-' || c == '+') && isdigit(date[1]))
                        match = match_tz(date, &offset);
 
@@ -285,11 +442,11 @@ void parse_date(char *date, char *result, int maxlen)
                offset = (then - mktime(&tm)) / 60;
 
        if (then == -1)
-               return;
-
-       then -= offset * 60;
+               return -1;
 
-       snprintf(result, maxlen, "%lu %+03d%02d", then, offset/60, offset % 60);
+       if (!tm_gmt)
+               then -= offset * 60;
+       return date_string(then, offset, result, maxlen);
 }
 
 void datestamp(char *buf, int bufsize)
@@ -302,5 +459,188 @@ void datestamp(char *buf, int bufsize)
        offset = my_mktime(localtime(&now)) - now;
        offset /= 60;
 
-       snprintf(buf, bufsize, "%lu %+05d", now, offset/60*100 + offset%60);
+       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 const struct special {
+       const char *name;
+       void (*fn)(struct tm *, int *);
+} special[] = {
+       { "yesterday", date_yesterday },
+       { "noon", date_noon },
+       { "midnight", date_midnight },
+       { "tea", date_tea },
+       { 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 n = 1, i;
+
+       while (isalpha(*++end))
+               n++;
+
+       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;
+}
+
+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)) {
+                       char *end;
+                       number = strtoul(date-1, &end, 10);
+                       date = end;
+                       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--;
+       return mktime(&tm);
 }