sha1-file: support OBJECT_INFO_FOR_PREFETCH

Teach oid_object_info_extended() to support a new flag that inhibits
fetching of missing objects. This is equivalent to setting
fetch_is_missing to 0, calling oid_object_info_extended(), then setting
fetch_if_missing to whatever it was before. Update unpack-trees.c to use
this new flag instead of repeatedly setting fetch_if_missing.

This new flag complicates things slightly in that there are now 2 ways
to do the same thing. But this eliminates the need to repeatedly set a
global variable, and more importantly, allows prefetching to be done in
parallel (in the future); hence, this patch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 9 insertions, 8 deletions

diff --git a/unpack-trees.c b/unpack-trees.c
index 22c41a3ba8..381b0cd65e 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -404,20 +404,21 @@ static int check_updates(struct unpack_trees_options *o)
 		 * below.
 		 */
 		struct oid_array to_fetch = OID_ARRAY_INIT;
-		int fetch_if_missing_store = fetch_if_missing;
-		fetch_if_missing = 0;
 		for (i = 0; i < index->cache_nr; i++) {
 			struct cache_entry *ce = index->cache[i];
-			if ((ce->ce_flags & CE_UPDATE) &&
-			    !S_ISGITLINK(ce->ce_mode)) {
-				if (!has_object_file(&ce->oid))
-					oid_array_append(&to_fetch, &ce->oid);
-			}
+
+			if (!(ce->ce_flags & CE_UPDATE) ||
+			    S_ISGITLINK(ce->ce_mode))
+				continue;
+			if (!oid_object_info_extended(the_repository, &ce->oid,
+						      NULL,
+						      OBJECT_INFO_FOR_PREFETCH))
+				continue;
+			oid_array_append(&to_fetch, &ce->oid);
 		}
 		if (to_fetch.nr)
 			fetch_objects(repository_format_partial_clone,
 				      to_fetch.oid, to_fetch.nr);
-		fetch_if_missing = fetch_if_missing_store;
 		oid_array_clear(&to_fetch);
 	}
 	for (i = 0; i < index->cache_nr; i++) {