files-backend: add and use files_ref_path()

Keep repo-related path handling in one place. This will make it easier
to add submodule/multiworktree support later.

This automatically adds the "if submodule then use the submodule version
of git_path" to other call sites too. But it does not mean those
operations are submodule-ready. Not yet.

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

refs/files-backend.c

@@ -1180,6 +1180,18 @@ static void files_reflog_path(struct files_ref_store *refs,
 	strbuf_git_path(sb, "logs/%s", refname);
 }
 
+static void files_ref_path(struct files_ref_store *refs,
+			   struct strbuf *sb,
+			   const char *refname)
+{
+	if (refs->submodule) {
+		strbuf_git_path_submodule(sb, refs->submodule, "%s", refname);
+		return;
+	}
+
+	strbuf_git_path(sb, "%s", refname);
+}
+
 /*
  * Get the packed_ref_cache for the specified files_ref_store,
  * creating it if necessary.
@@ -1249,19 +1261,10 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir)
 	struct strbuf refname;
 	struct strbuf path = STRBUF_INIT;
 	size_t path_baselen;
-	int err = 0;
 
-	if (refs->submodule)
+	files_ref_path(refs, &path, dirname);
-		err = strbuf_git_path_submodule(&path, refs->submodule, "%s", dirname);
-	else
-		strbuf_git_path(&path, "%s", dirname);
 	path_baselen = path.len;
 
-	if (err) {
-		strbuf_release(&path);
-		return;
-	}
-
 	d = opendir(path.buf);
 	if (!d) {
 		strbuf_release(&path);
@@ -1396,10 +1399,7 @@ static int files_read_raw_ref(struct ref_store *ref_store,
 	*type = 0;
 	strbuf_reset(&sb_path);
 
-	if (refs->submodule)
+	files_ref_path(refs, &sb_path, refname);
-		strbuf_git_path_submodule(&sb_path, refs->submodule, "%s", refname);
-	else
-		strbuf_git_path(&sb_path, "%s", refname);
 
 	path = sb_path.buf;
 
@@ -1587,7 +1587,7 @@ static int lock_raw_ref(struct files_ref_store *refs,
 	*lock_p = lock = xcalloc(1, sizeof(*lock));
 
 	lock->ref_name = xstrdup(refname);
-	strbuf_git_path(&ref_file, "%s", refname);
+	files_ref_path(refs, &ref_file, refname);
 
 retry:
 	switch (safe_create_leading_directories(ref_file.buf)) {
@@ -2056,7 +2056,7 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
 	if (flags & REF_DELETING)
 		resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
 
-	strbuf_git_path(&ref_file, "%s", refname);
+	files_ref_path(refs, &ref_file, refname);
 	resolved = !!resolve_ref_unsafe(refname, resolve_flags,
 					lock->old_oid.hash, type);
 	if (!resolved && errno == EISDIR) {
@@ -2355,7 +2355,7 @@ static void try_remove_empty_parents(struct files_ref_store *refs,
 		strbuf_setlen(&buf, q - buf.buf);
 
 		strbuf_reset(&sb);
-		strbuf_git_path(&sb, "%s", buf.buf);
+		files_ref_path(refs, &sb, buf.buf);
 		if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
 			flags &= ~REMOVE_EMPTY_PARENTS_REF;
 
@@ -2672,7 +2672,7 @@ static int files_rename_ref(struct ref_store *ref_store,
 			struct strbuf path = STRBUF_INIT;
 			int result;
 
-			strbuf_git_path(&path, "%s", newrefname);
+			files_ref_path(refs, &path, newrefname);
 			result = remove_empty_directories(&path);
 			strbuf_release(&path);
 
@@ -3906,7 +3906,7 @@ static int files_transaction_commit(struct ref_store *ref_store,
 			    update->type & REF_ISSYMREF) {
 				/* It is a loose reference. */
 				strbuf_reset(&sb);
-				strbuf_git_path(&sb, "%s", lock->ref_name);
+				files_ref_path(refs, &sb, lock->ref_name);
 				if (unlink_or_msg(sb.buf, err)) {
 					ret = TRANSACTION_GENERIC_ERROR;
 					goto cleanup;
@@ -4206,19 +4206,18 @@ static int files_reflog_expire(struct ref_store *ref_store,
 
 static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
 {
+	struct files_ref_store *refs =
+		files_downcast(ref_store, 0, "init_db");
 	struct strbuf sb = STRBUF_INIT;
 
-	/* Check validity (but we don't need the result): */
-	files_downcast(ref_store, 0, "init_db");
-
 	/*
 	 * Create .git/refs/{heads,tags}
 	 */
-	strbuf_git_path(&sb, "refs/heads");
+	files_ref_path(refs, &sb, "refs/heads");
 	safe_create_dir(sb.buf, 1);
 
 	strbuf_reset(&sb);
-	strbuf_git_path(&sb, "refs/tags");
+	files_ref_path(refs, &sb, "refs/tags");
 	safe_create_dir(sb.buf, 1);
 
 	strbuf_release(&sb);