refs: remove some functions from the module's public interface

The following functions are no longer used from outside the refs
module:

* lock_packed_refs()
* add_packed_ref()
* commit_packed_refs()
* rollback_packed_refs()

So make these functions private.

This is an important step, because it means that nobody outside of the
refs module needs to know the difference between loose and packed
references.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -1314,7 +1314,13 @@ static struct ref_dir *get_packed_refs(struct ref_cache *refs)
 	return get_packed_ref_dir(get_packed_ref_cache(refs));
 }
 
-void add_packed_ref(const char *refname, const unsigned char *sha1)
+/*
+ * Add a reference to the in-memory packed reference cache.  This may
+ * only be called while the packed-refs file is locked (see
+ * lock_packed_refs()).  To actually write the packed-refs file, call
+ * commit_packed_refs().
+ */
+static void add_packed_ref(const char *refname, const unsigned char *sha1)
 {
 	struct packed_ref_cache *packed_ref_cache =
 		get_packed_ref_cache(&ref_cache);
@@ -2515,8 +2521,12 @@ static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
 	return 0;
 }
 
-/* This should return a meaningful errno on failure */
-int lock_packed_refs(int flags)
+/*
+ * Lock the packed-refs file for writing. Flags is passed to
+ * hold_lock_file_for_update(). Return 0 on success. On errors, set
+ * errno appropriately and return a nonzero value.
+ */
+static int lock_packed_refs(int flags)
 {
 	static int timeout_configured = 0;
 	static int timeout_value = 1000;
@@ -2546,10 +2556,12 @@ int lock_packed_refs(int flags)
 }
 
 /*
- * Commit the packed refs changes.
- * On error we must make sure that errno contains a meaningful value.
+ * Write the current version of the packed refs cache from memory to
+ * disk. The packed-refs file must already be locked for writing (see
+ * lock_packed_refs()). Return zero on success. On errors, set errno
+ * and return a nonzero value
  */
-int commit_packed_refs(void)
+static int commit_packed_refs(void)
 {
 	struct packed_ref_cache *packed_ref_cache =
 		get_packed_ref_cache(&ref_cache);
@@ -2578,7 +2590,12 @@ int commit_packed_refs(void)
 	return error;
 }
 
-void rollback_packed_refs(void)
+/*
+ * Rollback the lockfile for the packed-refs file, and discard the
+ * in-memory packed reference cache.  (The packed-refs file will be
+ * read anew if it is needed again after this function is called.)
+ */
+static void rollback_packed_refs(void)
 {
 	struct packed_ref_cache *packed_ref_cache =
 		get_packed_ref_cache(&ref_cache);

refs.h

@@ -110,36 +110,6 @@ extern int for_each_rawref(each_ref_fn, void *);
 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
 
-/*
- * Lock the packed-refs file for writing.  Flags is passed to
- * hold_lock_file_for_update().  Return 0 on success.
- * Errno is set to something meaningful on error.
- */
-extern int lock_packed_refs(int flags);
-
-/*
- * Add a reference to the in-memory packed reference cache.  This may
- * only be called while the packed-refs file is locked (see
- * lock_packed_refs()).  To actually write the packed-refs file, call
- * commit_packed_refs().
- */
-extern void add_packed_ref(const char *refname, const unsigned char *sha1);
-
-/*
- * Write the current version of the packed refs cache from memory to
- * disk.  The packed-refs file must already be locked for writing (see
- * lock_packed_refs()).  Return zero on success.
- * Sets errno to something meaningful on error.
- */
-extern int commit_packed_refs(void);
-
-/*
- * Rollback the lockfile for the packed-refs file, and discard the
- * in-memory packed reference cache.  (The packed-refs file will be
- * read anew if it is needed again after this function is called.)
- */
-extern void rollback_packed_refs(void);
-
 /*
  * Flags for controlling behaviour of pack_refs()
  * PACK_REFS_PRUNE: Prune loose refs after packing