Store peeled refs in packed-refs (take 2).

This fixes the previous implementation which failed to optimize
repositories with tons of lightweight tags.  The updated
packed-refs format begins with "# packed-refs with:" line that
lists the kind of extended data the file records.  Currently,
there is only one such extension defined, "peeled".  This stores
the "peeled tag" on a line that immediately follows a line for a
tag object itself in the format "^<sha-1>".

The header line itself and any extended data are ignored by
older implementation, so packed-refs file generated with this
version can still be used by older git.  packed-refs made by
older git can of course be used with this version.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 3 insertions, 4 deletions

diff --git a/refs.h b/refs.h
index 40048a6919..cd1e1d620e 100644
--- a/refs.h
+++ b/refs.h
@@ -10,14 +10,13 @@ struct ref_lock {
 	int force_write;
 };
 
+#define REF_ISSYMREF 01
+#define REF_ISPACKED 02
+
 /*
  * Calls the specified function for each ref file until it returns nonzero,
  * and returns the value
  */
-#define REF_ISSYMREF 01
-#define REF_ISPACKED 02
-#define REF_ISPEELED 04 /* internal use */
-
 typedef int each_ref_fn(const char *refname, const unsigned char *sha1, int flags, void *cb_data);
 extern int head_ref(each_ref_fn, void *);
 extern int for_each_ref(each_ref_fn, void *);