refs: convert ref storage format to an enum

The ref storage format is tracked as a simple unsigned integer, which
makes it harder than necessary to discover what that integer actually is
or where its values are defined.

Convert the ref storage format to instead be an enum.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/refs.h b/refs.h
index fe7f0db35e..a7afa9bede 100644
--- a/refs.h
+++ b/refs.h
@@ -11,8 +11,14 @@ struct string_list;
 struct string_list_item;
 struct worktree;
 
-unsigned int ref_storage_format_by_name(const char *name);
-const char *ref_storage_format_to_name(unsigned int ref_storage_format);
+enum ref_storage_format {
+	REF_STORAGE_FORMAT_UNKNOWN,
+	REF_STORAGE_FORMAT_FILES,
+	REF_STORAGE_FORMAT_REFTABLE,
+};
+
+enum ref_storage_format ref_storage_format_by_name(const char *name);
+const char *ref_storage_format_to_name(enum ref_storage_format ref_storage_format);
 
 /*
  * Resolve a reference, recursively following symbolic refererences.