From abbfe8e92e549bfb080d8990d78fbfc6083b2f67 Mon Sep 17 00:00:00 2001
From: Christopher Haster <chaster@utexas.edu>
Date: Sun, 10 Apr 2022 23:24:11 -0500
Subject: [PATCH] Reduced lfs_dir_traverse's explicit stack to 3 frames

This is possible thanks to invoxiaamo's optimization of compacting
renames to avoid the O(n^3) nested filters. Not only does this
significantly reduce the runtime cost of that operation, but it
reduces the maximum possible depth of recursion to 3 frames.

Deepest lfs_dir_traverse before:

traverse with commit
'-> traverse with filter
    '-> traverse with move
        '-> traverse with filter

Deepest lfs_dir_traverse after:

traverse with commit
'-> traverse with move
    '-> traverse with filter
---
 lfs.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lfs.c b/lfs.c
index 801e118..117595e 100644
--- a/lfs.c
+++ b/lfs.c
@@ -767,11 +767,10 @@ static int lfs_dir_traverse_filter(void *p,
 // maximum recursive depth of lfs_dir_traverse, the deepest call:
 //
 // traverse with commit
-// '-> traverse with filter
-//     '-> traverse with move
-//         ' traverse with filter
+// '-> traverse with move
+//     '-> traverse with filter
 //
-#define LFS_DIR_TRAVERSE_DEPTH 4
+#define LFS_DIR_TRAVERSE_DEPTH 3
 
 struct lfs_dir_traverse {
     const lfs_mdir_t *dir;