Refactor parse_date for approxidate functions

approxidate_relative and approxidate_careful both use parse_date to
dump the timestamp to a character buffer and parse it back into a long
unsigned using strtoul(). Avoid doing this by creating a new
parse_date_toffset method.

Noticed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/date.c b/date.c
index 002aa3c8d6d4ff08d8790a155b8979bc117a2b95..610ecf75075aee90eabf65d198f7a28ba629a970 100644 (file)
--- a/date.c
+++ b/date.c
@@ -585,11 +585,17 @@ static int date_string(unsigned long date, int offset, char *buf, int len)
 
 /* 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(const char *date, char *result, int maxlen)
+int parse_date_toffset(const char *date, unsigned long *timestamp, int *offset)
 {
        struct tm tm;
-       int offset, tm_gmt;
-       time_t then;
+       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;
@@ -599,7 +605,7 @@ int parse_date(const char *date, char *result, int maxlen)
        tm.tm_hour = -1;
        tm.tm_min = -1;
        tm.tm_sec = -1;
-       offset = -1;
+       *offset = -1;
        tm_gmt = 0;
 
        for (;;) {
@@ -611,11 +617,11 @@ int parse_date(const char *date, char *result, int maxlen)
                        break;
 
                if (isalpha(c))
-                       match = match_alpha(date, &tm, &offset);
+                       match = match_alpha(date, &tm, offset);
                else if (isdigit(c))
-                       match = match_digit(date, &tm, &offset, &tm_gmt);
+                       match = match_digit(date, &tm, offset, &tm_gmt);
                else if ((c == '-' || c == '+') && isdigit(date[1]))
-                       match = match_tz(date, &offset);
+                       match = match_tz(date, offset);
 
                if (!match) {
                        /* BAD CRAP */
@@ -626,16 +632,26 @@ int parse_date(const char *date, char *result, int maxlen)
        }
 
        /* mktime uses local timezone */
-       then = tm_to_time_t(&tm);
-       if (offset == -1)
-               offset = (then - mktime(&tm)) / 60;
+       *timestamp = tm_to_time_t(&tm);
+       if (*offset == -1)
+               *offset = (*timestamp - mktime(&tm)) / 60;
 
-       if (then == -1)
+       if (*timestamp == -1)
                return -1;
 
        if (!tm_gmt)
-               then -= offset * 60;
-       return date_string(then, offset, result, maxlen);
+               *timestamp -= *offset * 60;
+       return 1; /* success */
+}
+
+int parse_date(const char *date, char *result, int maxlen)
+{
+       unsigned long timestamp;
+       int offset;
+       if (parse_date_toffset(date, &timestamp, &offset) > 0)
+               return date_string(timestamp, offset, result, maxlen);
+       else
+               return -1;
 }
 
 enum date_mode parse_date_format(const char *format)
@@ -983,11 +999,12 @@ static unsigned long approxidate_str(const char *date,
 
 unsigned long approxidate_relative(const char *date, const struct timeval *tv)
 {
-       char buffer[50];
+       unsigned long timestamp;
+       int offset;
        int errors = 0;
 
-       if (parse_date(date, buffer, sizeof(buffer)) > 0)
-               return strtoul(buffer, NULL, 0);
+       if (parse_date_toffset(date, &timestamp, &offset) > 0)
+               return timestamp;
 
        return approxidate_str(date, tv, &errors);
 }
@@ -995,14 +1012,15 @@ unsigned long approxidate_relative(const char *date, const struct timeval *tv)
 unsigned long approxidate_careful(const char *date, int *error_ret)
 {
        struct timeval tv;
-       char buffer[50];
+       unsigned long timestamp;
+       int offset;
        int dummy = 0;
        if (!error_ret)
                error_ret = &dummy;
 
-       if (parse_date(date, buffer, sizeof(buffer)) > 0) {
+       if (parse_date_toffset(date, &timestamp, &offset) > 0) {
                *error_ret = 0;
-               return strtoul(buffer, NULL, 0);
+               return timestamp;
        }
 
        gettimeofday(&tv, NULL);