date: use strbufs in date-formatting functions

Many of the date functions write into fixed-size buffers.
This is a minor pain, as we have to take special
precautions, and frequently end up copying the result into a
strbuf or heap-allocated buffer anyway (for which we
sometimes use strcpy!).

Let's instead teach parse_date, datestamp, etc to write to a
strbuf. The obvious downside is that we might need to
perform a heap allocation where we otherwise would not need
to. However, it turns out that the only two new allocations
required are:

1. In test-date.c, where we don't care about efficiency.

2. In determine_author_info, which is not performance
critical (and where the use of a strbuf will help later
refactoring).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/commit.c b/builtin/commit.c
index 5ed60364ce5eb1f458e1f5155d76abd7341d24ea..8da0a9f3e365e7a0aefadb34bcd8fab046c54726 100644 (file)
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -520,19 +520,16 @@ static int sane_ident_split(struct ident_split *person)
        return 1;
 }
 
-static int parse_force_date(const char *in, char *out, int len)
+static int parse_force_date(const char *in, struct strbuf *out)
 {
-       if (len < 1)
-               return -1;
-       *out++ = '@';
-       len--;
+       strbuf_addch(out, '@');
 
-       if (parse_date(in, out, len) < 0) {
+       if (parse_date(in, out) < 0) {
                int errors = 0;
                unsigned long t = approxidate_careful(in, &errors);
                if (errors)
                        return -1;
-               snprintf(out, len, "%lu", t);
+               strbuf_addf(out, "%lu", t);
        }
 
        return 0;
@@ -542,7 +539,7 @@ static void determine_author_info(struct strbuf *author_ident)
 {
        char *name, *email, *date;
        struct ident_split author;
-       char date_buf[64];
+       struct strbuf date_buf = STRBUF_INIT;
 
        name = getenv("GIT_AUTHOR_NAME");
        email = getenv("GIT_AUTHOR_EMAIL");
@@ -588,9 +585,10 @@ static void determine_author_info(struct strbuf *author_ident)
        }
 
        if (force_date) {
-               if (parse_force_date(force_date, date_buf, sizeof(date_buf)))
+               strbuf_reset(&date_buf);
+               if (parse_force_date(force_date, &date_buf))
                        die(_("invalid date format: %s"), force_date);
-               date = date_buf;
+               date = date_buf.buf;
        }
 
        strbuf_addstr(author_ident, fmt_ident(name, email, date, IDENT_STRICT));
@@ -600,6 +598,8 @@ static void determine_author_info(struct strbuf *author_ident)
                export_one("GIT_AUTHOR_EMAIL", author.mail_begin, author.mail_end, 0);
                export_one("GIT_AUTHOR_DATE", author.date_begin, author.tz_end, '@');
        }
+
+       strbuf_release(&date_buf);
 }
 
 static void split_ident_or_die(struct ident_split *id, const struct strbuf *buf)

diff --git a/cache.h b/cache.h
index fcb511db70f7703f2b29dbc89dcf703065c823fe..96ecc1f15881401fccc2a745e487b69e07b22d97 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -1044,10 +1044,10 @@ enum date_mode {
 const char *show_date(unsigned long time, int timezone, enum date_mode mode);
 void show_date_relative(unsigned long time, int tz, const struct timeval *now,
                        struct strbuf *timebuf);
-int parse_date(const char *date, char *buf, int bufsize);
+int parse_date(const char *date, struct strbuf *out);
 int parse_date_basic(const char *date, unsigned long *timestamp, int *offset);
 int parse_expiry_date(const char *date, unsigned long *timestamp);
-void datestamp(char *buf, int bufsize);
+void datestamp(struct strbuf *out);
 #define approxidate(s) approxidate_careful((s), NULL)
 unsigned long approxidate_careful(const char *, int *);
 unsigned long approxidate_relative(const char *date, const struct timeval *now);

diff --git a/date.c b/date.c
index 782de95d90c6ac1a02ddfa0df81ca93ecdf910c4..2c33468dfbf445017a1925065004646942a3cb75 100644 (file)
--- a/date.c
+++ b/date.c
@@ -605,7 +605,7 @@ static int match_tz(const char *date, int *offp)
        return end - date;
 }
 
-static int date_string(unsigned long date, int offset, char *buf, int len)
+static void date_string(unsigned long date, int offset, struct strbuf *buf)
 {
        int sign = '+';
 
@@ -613,7 +613,7 @@ static int date_string(unsigned long date, int offset, char *buf, int len)
                offset = -offset;
                sign = '-';
        }
-       return snprintf(buf, len, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
+       strbuf_addf(buf, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
 }
 
 /*
@@ -735,13 +735,14 @@ int parse_expiry_date(const char *date, unsigned long *timestamp)
        return errors;
 }
 
-int parse_date(const char *date, char *result, int maxlen)
+int parse_date(const char *date, struct strbuf *result)
 {
        unsigned long timestamp;
        int offset;
        if (parse_date_basic(date, &timestamp, &offset))
                return -1;
-       return date_string(timestamp, offset, result, maxlen);
+       date_string(timestamp, offset, result);
+       return 0;
 }
 
 enum date_mode parse_date_format(const char *format)
@@ -766,7 +767,7 @@ enum date_mode parse_date_format(const char *format)
                die("unknown date format %s", format);
 }
 
-void datestamp(char *buf, int bufsize)
+void datestamp(struct strbuf *out)
 {
        time_t now;
        int offset;
@@ -776,7 +777,7 @@ void datestamp(char *buf, int bufsize)
        offset = tm_to_time_t(localtime(&now)) - now;
        offset /= 60;
 
-       date_string(now, offset, buf, bufsize);
+       date_string(now, offset, out);
 }
 
 /*

diff --git a/fast-import.c b/fast-import.c
index d73f58cbe3fe4522fa24d47f9086d927b3296c8b..dc9f7a8ccbb303168d63c0401b8a5d61eab97e4b 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -1971,7 +1971,7 @@ static int parse_data(struct strbuf *sb, uintmax_t limit, uintmax_t *len_res)
        return 1;
 }
 
-static int validate_raw_date(const char *src, char *result, int maxlen)
+static int validate_raw_date(const char *src, struct strbuf *result)
 {
        const char *orig_src = src;
        char *endp;
@@ -1989,11 +1989,10 @@ static int validate_raw_date(const char *src, char *result, int maxlen)
                return -1;
 
        num = strtoul(src + 1, &endp, 10);
-       if (errno || endp == src + 1 || *endp || (endp - orig_src) >= maxlen ||
-           1400 < num)
+       if (errno || endp == src + 1 || *endp || 1400 < num)
                return -1;
 
-       strcpy(result, orig_src);
+       strbuf_addstr(result, orig_src);
        return 0;
 }
 
@@ -2001,7 +2000,7 @@ static char *parse_ident(const char *buf)
 {
        const char *ltgt;
        size_t name_len;
-       char *ident;
+       struct strbuf ident = STRBUF_INIT;
 
        /* ensure there is a space delimiter even if there is no name */
        if (*buf == '<')
@@ -2020,26 +2019,25 @@ static char *parse_ident(const char *buf)
                die("Missing space after > in ident string: %s", buf);
        ltgt++;
        name_len = ltgt - buf;
-       ident = xmalloc(name_len + 24);
-       strncpy(ident, buf, name_len);
+       strbuf_add(&ident, buf, name_len);
 
        switch (whenspec) {
        case WHENSPEC_RAW:
-               if (validate_raw_date(ltgt, ident + name_len, 24) < 0)
+               if (validate_raw_date(ltgt, &ident) < 0)
                        die("Invalid raw date \"%s\" in ident: %s", ltgt, buf);
                break;
        case WHENSPEC_RFC2822:
-               if (parse_date(ltgt, ident + name_len, 24) < 0)
+               if (parse_date(ltgt, &ident) < 0)
                        die("Invalid rfc2822 date \"%s\" in ident: %s", ltgt, buf);
                break;
        case WHENSPEC_NOW:
                if (strcmp("now", ltgt))
                        die("Date in ident must be 'now': %s", buf);
-               datestamp(ident + name_len, 24);
+               datestamp(&ident);
                break;
        }
 
-       return ident;
+       return strbuf_detach(&ident, NULL);
 }
 
 static void parse_and_store_blob(

diff --git a/ident.c b/ident.c
index 1d9b6e770d02d12f77b417e05aca5134eccf1c40..9bcc4e11b859773c68784530febb529073fda41a 100644 (file)
--- a/ident.c
+++ b/ident.c
@@ -9,7 +9,7 @@
 
 static struct strbuf git_default_name = STRBUF_INIT;
 static struct strbuf git_default_email = STRBUF_INIT;
-static char git_default_date[50];
+static struct strbuf git_default_date = STRBUF_INIT;
 
 #define IDENT_NAME_GIVEN 01
 #define IDENT_MAIL_GIVEN 02
@@ -129,9 +129,9 @@ const char *ident_default_email(void)
 
 static const char *ident_default_date(void)
 {
-       if (!git_default_date[0])
-               datestamp(git_default_date, sizeof(git_default_date));
-       return git_default_date;
+       if (!git_default_date.len)
+               datestamp(&git_default_date);
+       return git_default_date.buf;
 }
 
 static int crud(unsigned char c)
@@ -292,7 +292,6 @@ const char *fmt_ident(const char *name, const char *email,
                      const char *date_str, int flag)
 {
        static struct strbuf ident = STRBUF_INIT;
-       char date[50];
        int strict = (flag & IDENT_STRICT);
        int want_date = !(flag & IDENT_NO_DATE);
        int want_name = !(flag & IDENT_NO_NAME);
@@ -320,15 +319,6 @@ const char *fmt_ident(const char *name, const char *email,
                die("unable to auto-detect email address (got '%s')", email);
        }
 
-       if (want_date) {
-               if (date_str && date_str[0]) {
-                       if (parse_date(date_str, date, sizeof(date)) < 0)
-                               die("invalid date format: %s", date_str);
-               }
-               else
-                       strcpy(date, ident_default_date());
-       }
-
        strbuf_reset(&ident);
        if (want_name) {
                strbuf_addstr_without_crud(&ident, name);
@@ -339,8 +329,14 @@ const char *fmt_ident(const char *name, const char *email,
                        strbuf_addch(&ident, '>');
        if (want_date) {
                strbuf_addch(&ident, ' ');
-               strbuf_addstr_without_crud(&ident, date);
+               if (date_str && date_str[0]) {
+                       if (parse_date(date_str, &ident) < 0)
+                               die("invalid date format: %s", date_str);
+               }
+               else
+                       strbuf_addstr(&ident, ident_default_date());
        }
+
        return ident.buf;
 }
 

diff --git a/test-date.c b/test-date.c
index 10afaabbfaed9ee1b4a6a498a2110fb904d48645..94a6997a8f6aa40cd86859dbd3eb27704e46b034 100644 (file)
--- a/test-date.c
+++ b/test-date.c
@@ -19,19 +19,21 @@ static void show_dates(char **argv, struct timeval *now)
 
 static void parse_dates(char **argv, struct timeval *now)
 {
+       struct strbuf result = STRBUF_INIT;
+
        for (; *argv; argv++) {
-               char result[100];
                unsigned long t;
                int tz;
 
-               result[0] = 0;
-               parse_date(*argv, result, sizeof(result));
-               if (sscanf(result, "%lu %d", &t, &tz) == 2)
+               strbuf_reset(&result);
+               parse_date(*argv, &result);
+               if (sscanf(result.buf, "%lu %d", &t, &tz) == 2)
                        printf("%s -> %s\n",
                               *argv, show_date(t, tz, DATE_ISO8601));
                else
                        printf("%s -> bad\n", *argv);
        }
+       strbuf_release(&result);
 }
 
 static void parse_approxidate(char **argv, struct timeval *now)