refs: rename get_ref_store() to get_submodule_ref_store() and make it public

This function is intended to replace *_submodule() refs API. It provides
a ref store for a specific submodule, which can be operated on by a new
set of refs API.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -1171,7 +1171,7 @@ int head_ref(each_ref_fn fn, void *cb_data)
 static int do_for_each_ref(const char *submodule, const char *prefix,
 			   each_ref_fn fn, int trim, int flags, void *cb_data)
 {
-	struct ref_store *refs = get_ref_store(submodule);
+	struct ref_store *refs = get_submodule_ref_store(submodule);
 	struct ref_iterator *iter;
 
 	if (!refs)
@@ -1344,10 +1344,10 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
 		/* We need to strip off one or more trailing slashes */
 		char *stripped = xmemdupz(submodule, len);
 
-		refs = get_ref_store(stripped);
+		refs = get_submodule_ref_store(stripped);
 		free(stripped);
 	} else {
-		refs = get_ref_store(submodule);
+		refs = get_submodule_ref_store(submodule);
 	}
 
 	if (!refs)
@@ -1460,13 +1460,17 @@ static void register_submodule_ref_store(struct ref_store *refs,
 		    submodule);
 }
 
-struct ref_store *get_ref_store(const char *submodule)
+struct ref_store *get_submodule_ref_store(const char *submodule)
 {
 	struct strbuf submodule_sb = STRBUF_INIT;
 	struct ref_store *refs;
 	int ret;
 
 	if (!submodule || !*submodule) {
+		/*
+		 * FIXME: This case is ideally not allowed. But that
+		 * can't happen until we clean up all the callers.
+		 */
 		return get_main_ref_store();
 	}
 

refs.h

@@ -562,5 +562,16 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 int ref_storage_backend_exists(const char *name);
 
 struct ref_store *get_main_ref_store(void);
+/*
+ * Return the ref_store instance for the specified submodule. For the
+ * main repository, use submodule==NULL; such a call cannot fail. For
+ * a submodule, the submodule must exist and be a nonbare repository,
+ * otherwise return NULL. If the requested reference store has not yet
+ * been initialized, initialize it first.
+ *
+ * For backwards compatibility, submodule=="" is treated the same as
+ * submodule==NULL.
+ */
+struct ref_store *get_submodule_ref_store(const char *submodule);
 
 #endif /* REFS_H */

refs/refs-internal.h

@@ -646,18 +646,6 @@ struct ref_store {
 void base_ref_store_init(struct ref_store *refs,
 			 const struct ref_storage_be *be);
 
-/*
- * Return the ref_store instance for the specified submodule. For the
- * main repository, use submodule==NULL; such a call cannot fail. For
- * a submodule, the submodule must exist and be a nonbare repository,
- * otherwise return NULL. If the requested reference store has not yet
- * been initialized, initialize it first.
- *
- * For backwards compatibility, submodule=="" is treated the same as
- * submodule==NULL.
- */
-struct ref_store *get_ref_store(const char *submodule);
-
 const char *resolve_ref_recursively(struct ref_store *refs,
 				    const char *refname,
 				    int resolve_flags,