refs: add method iterator_begin

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

refs.c

@@ -1157,7 +1157,7 @@ static int do_for_each_ref(const char *submodule, const char *prefix,
 	if (!refs)
 		return 0;
 
-	iter = files_ref_iterator_begin(refs, prefix, flags);
+	iter = refs->be->iterator_begin(refs, prefix, flags);
 	iter = prefix_ref_iterator_begin(iter, prefix, trim);
 
 	return do_for_each_ref_iterator(iter, fn, cb_data);

refs/files-backend.c

@@ -1862,7 +1862,7 @@ static struct ref_iterator_vtable files_ref_iterator_vtable = {
 	files_ref_iterator_abort
 };
 
-struct ref_iterator *files_ref_iterator_begin(
+static struct ref_iterator *files_ref_iterator_begin(
 		struct ref_store *ref_store,
 		const char *prefix, unsigned int flags)
 {
@@ -4044,6 +4044,7 @@ struct ref_storage_be refs_be_files = {
 	files_peel_ref,
 	files_create_symref,
 
+	files_ref_iterator_begin,
 	files_read_raw_ref,
 	files_verify_refname_available
 };

refs/refs-internal.h

@@ -404,18 +404,6 @@ struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 					       const char *prefix,
 					       int trim);
 
-struct ref_store;
-
-/*
- * Iterate over the packed and loose references in the specified
- * ref_store that are within find_containing_dir(prefix). If prefix is
- * NULL or the empty string, iterate over all references in the
- * submodule.
- */
-struct ref_iterator *files_ref_iterator_begin(struct ref_store *ref_store,
-					      const char *prefix,
-					      unsigned int flags);
-
 /*
  * Iterate over the references in the main ref_store that have a
  * reflog. The paths within a directory are iterated over in arbitrary
@@ -488,6 +476,8 @@ int do_for_each_ref_iterator(struct ref_iterator *iter,
 
 /* refs backends */
 
+struct ref_store;
+
 /*
  * Initialize the ref_store for the specified submodule, or for the
  * main repository if submodule == NULL. These functions should call
@@ -508,6 +498,15 @@ typedef int create_symref_fn(struct ref_store *ref_store,
 			     const char *refs_heads_master,
 			     const char *logmsg);
 
+/*
+ * Iterate over the references in the specified ref_store that are
+ * within find_containing_dir(prefix). If prefix is NULL or the empty
+ * string, iterate over all references in the submodule.
+ */
+typedef struct ref_iterator *ref_iterator_begin_fn(
+		struct ref_store *ref_store,
+		const char *prefix, unsigned int flags);
+
 /*
  * Read a reference from the specified reference store, non-recursively.
  * Set type to describe the reference, and:
@@ -566,6 +565,7 @@ struct ref_storage_be {
 	peel_ref_fn *peel_ref;
 	create_symref_fn *create_symref;
 
+	ref_iterator_begin_fn *iterator_begin;
 	read_raw_ref_fn *read_raw_ref;
 	verify_refname_available_fn *verify_refname_available;
 };