[PATCH] index: add trace2 region for clear skip worktree

["Anh Le via GitGitGadget" <gitgitgadget@gmail.com>]

From: Anh Le <anh@canva.com>

In a large repository using sparse checkout, checking
whether a file marked with skip worktree is present
on disk and its skip worktree bit should be cleared
can take a considerable amount of time. Add a trace2
region to surface this information.

Signed-off-by: Anh Le <anh@canva.com>
---
    index: add trace2 region for clear skip worktree
    
    In large repository using sparse checkout, checking whether a file
    marked with skip worktree is present on disk and its skip worktree bit
    should be cleared can take a considerable amount of time. Add a trace2
    region to surface this information.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1368%2FHaizzz%2Fmaster-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1368/Haizzz/master-v1
Pull-Request: https://github.com/git/git/pull/1368

 sparse-index.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/sparse-index.c b/sparse-index.c
index e4a54ce1943..d11049c8aeb 100644
--- a/sparse-index.c
+++ b/sparse-index.c
@@ -493,24 +493,33 @@ void clear_skip_worktree_from_present_files(struct index_state *istate)
 	int dir_found = 1;
 
 	int i;
+	intmax_t path_count = 0;
+	intmax_t restart_count = 0;
 
 	if (!core_apply_sparse_checkout ||
 	    sparse_expect_files_outside_of_patterns)
 		return;
 
+	trace2_region_enter("index", "clear_skip_worktree_from_present_files", istate->repo);
 restart:
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce = istate->cache[i];
 
-		if (ce_skip_worktree(ce) &&
-		    path_found(ce->name, &last_dirname, &dir_len, &dir_found)) {
-			if (S_ISSPARSEDIR(ce->ce_mode)) {
-				ensure_full_index(istate);
-				goto restart;
+		if (ce_skip_worktree(ce)) {
+			path_count++;
+			if (path_found(ce->name, &last_dirname, &dir_len, &dir_found)) {
+				if (S_ISSPARSEDIR(ce->ce_mode)) {
+					ensure_full_index(istate);
+					restart_count++;
+					goto restart;
+				}
+				ce->ce_flags &= ~CE_SKIP_WORKTREE;
 			}
-			ce->ce_flags &= ~CE_SKIP_WORKTREE;
 		}
 	}
+	trace2_data_intmax("index", istate->repo, "clear_skip_worktree_from_present_files/path_count", path_count);
+	trace2_data_intmax("index", istate->repo, "clear_skip_worktree_from_present_files/restart_count", restart_count);
+	trace2_region_leave("index", "clear_skip_worktree_from_present_files", istate->repo);
 }
 
 /*

base-commit: 1fc3c0ad407008c2f71dd9ae1241d8b75f8ef886
-- 
gitgitgadget