[PATCH 38/38] refs: implement iteration over only per-worktree refs

[Michael Haggerty <mhagger@alum.mit.edu>]

From: David Turner <dturner@twopensource.com>

Alternate refs backends might still use files to store per-worktree
refs. So provide a way to iterate over only the per-worktree references
in a ref_store. The other backend can set up a files ref_store and
iterate using the new DO_FOR_EACH_PER_WORKTREE_ONLY flag when iterating.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs/files-backend.c |  4 ++++
 refs/refs-internal.h | 10 +++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 53d0ba1..b5ad21c 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1802,6 +1802,10 @@ static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
 	int ok;
 
 	while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+		if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
+		    ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
+			continue;
+
 		if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
 		    !ref_resolves_to_object(iter->iter0->refname,
 					    iter->iter0->oid,
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index db891e6..6d97ed9 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -462,10 +462,18 @@ extern struct ref_iterator *current_ref_iter;
 int do_for_each_ref_iterator(struct ref_iterator *iter,
 			     each_ref_fn fn, void *cb_data);
 
-/* refs backends */
+/*
+ * Only include per-worktree refs in a do_for_each_ref*() iteration.
+ * Normally this will be used with a files ref_store, since that's
+ * where all reference backends will presumably store their
+ * per-worktree refs.
+ */
+#define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02
 
 struct ref_store;
 
+/* refs backends */
+
 /*
  * Initialize the ref_store for the specified submodule, or for the
  * main repository if submodule == NULL. These functions should call
-- 
2.8.1