pack: move nth_packed_object_{sha1,oid}

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

1 files changed, 31 insertions, 0 deletions

diff --git a/packfile.c b/packfile.c
index b2a3a217d3..cc8d0d7db8 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1636,3 +1636,34 @@ out:
 
 	return data;
 }
+
+const unsigned char *nth_packed_object_sha1(struct packed_git *p,
+					    uint32_t n)
+{
+	const unsigned char *index = p->index_data;
+	if (!index) {
+		if (open_pack_index(p))
+			return NULL;
+		index = p->index_data;
+	}
+	if (n >= p->num_objects)
+		return NULL;
+	index += 4 * 256;
+	if (p->index_version == 1) {
+		return index + 24 * n + 4;
+	} else {
+		index += 8;
+		return index + 20 * n;
+	}
+}
+
+const struct object_id *nth_packed_object_oid(struct object_id *oid,
+					      struct packed_git *p,
+					      uint32_t n)
+{
+	const unsigned char *hash = nth_packed_object_sha1(p, n);
+	if (!hash)
+		return NULL;
+	hashcpy(oid->hash, hash);
+	return oid;
+}