date API: create a date.h, split from cache.h

Move the declaration of the date.c functions from cache.h, and adjust
the relevant users to include the new date.h header.

The show_ident_date() function belonged in pretty.h (it's defined in
pretty.c), its two users outside of pretty.c didn't strictly need to
include pretty.h, as they get it indirectly, but let's add it to them
anyway.

Similarly, the change to "builtin/{fast-import,show-branch,tag}.c"
isn't needed as far as the compiler is concerned, but since they all
use the "DATE_MODE()" macro we now define in date.h, let's have them
include it.

We could simply include this new header in "cache.h", but as this
change shows these functions weren't common enough to warrant
including in it in the first place. By moving them out of cache.h
changes to this API will no longer cause a (mostly) full re-build of
the project when "make" is run.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/date.h b/date.h
new file mode 100644
index 0000000000..5db9ec8dd2
--- /dev/null
+++ b/date.h
@@ -0,0 +1,43 @@
+#ifndef DATE_H
+#define DATE_H
+
+enum date_mode_type {
+	DATE_NORMAL = 0,
+	DATE_HUMAN,
+	DATE_RELATIVE,
+	DATE_SHORT,
+	DATE_ISO8601,
+	DATE_ISO8601_STRICT,
+	DATE_RFC2822,
+	DATE_STRFTIME,
+	DATE_RAW,
+	DATE_UNIX
+};
+
+struct date_mode {
+	enum date_mode_type type;
+	const char *strftime_fmt;
+	int local;
+};
+
+/*
+ * Convenience helper for passing a constant type, like:
+ *
+ *   show_date(t, tz, DATE_MODE(NORMAL));
+ */
+#define DATE_MODE(t) date_mode_from_type(DATE_##t)
+struct date_mode *date_mode_from_type(enum date_mode_type type);
+
+const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
+void show_date_relative(timestamp_t time, struct strbuf *timebuf);
+int parse_date(const char *date, struct strbuf *out);
+int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
+int parse_expiry_date(const char *date, timestamp_t *timestamp);
+void datestamp(struct strbuf *out);
+#define approxidate(s) approxidate_careful((s), NULL)
+timestamp_t approxidate_careful(const char *, int *);
+timestamp_t approxidate_relative(const char *date);
+void parse_date_format(const char *format, struct date_mode *mode);
+int date_overflows(timestamp_t date);
+time_t tm_to_time_t(const struct tm *tm);
+#endif