From fafdf23b2f57bdf6a74513b3cc03902f0a8e954d Mon Sep 17 00:00:00 2001
From: Emily Yang <emilyyang.git@gmail.com>
Date: Fri, 17 Oct 2025 20:58:59 +0000
Subject: commit-graph: add new config for changed-paths & recommend it in
 scalar

The changed-path Bloom filters feature has proven stable and reliable
over several years of use, delivering significant performance
improvement for file history computation in large monorepos. Currently
a user can opt-in to writing the changed-path Bloom filters using the
"--changed-paths" option to "git commit-graph write". The filters will
be persisted until the user drops the filters using the
"--no-changed-paths" option. For this functionality, refer to 0087a87ba8
(commit-graph: persist existence of changed-paths, 2020-07-01).

Large monorepos using Git's background maintenance to build and update
commit-graph files could use an easy switch to enable this feature
without a foreground computation. In this commit, we're proposing a new
config option "commitGraph.changedPaths":

* If "true", "git commit-graph write" will write Bloom filters,
  equivalent to passing "--changed-paths";
* If "false" or "unset", Bloom filters will be written during "git
  commit-graph write" only if the filters already exist in the current
  commit-graph file. This matches the default behaviour of "git
  commit-graph write" without any "--[no-]changed-paths" option. Note
  "false" can disable a previous "true" config value but doesn't imply
  "--no-changed-paths".

This config will always respect the precedence of command line option
"--[no-]changed-paths".

We also set this new config as optional recommended config in scalar to
turn on this feature for large repos.

Helped-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Emily Yang <emilyyang.git@gmail.com>
Acked-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-commit-graph.adoc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'Documentation/git-commit-graph.adoc')

diff --git a/Documentation/git-commit-graph.adoc b/Documentation/git-commit-graph.adoc
index e9558173c0..6d19026035 100644
--- a/Documentation/git-commit-graph.adoc
+++ b/Documentation/git-commit-graph.adoc
@@ -71,7 +71,7 @@ take a while on large repositories. It provides significant performance gains
 for getting history of a directory or a file with `git log -- <path>`. If
 this option is given, future commit-graph writes will automatically assume
 that this option was intended. Use `--no-changed-paths` to stop storing this
-data.
+data. `--changed-paths` is implied by config `commitGraph.changedPaths=true`.
 +
 With the `--max-new-filters=<n>` option, generate at most `n` new Bloom
 filters (if `--changed-paths` is specified). If `n` is `-1`, no limit is
-- 
cgit v1.3

