From 6689a6ea493b484d6a43601f42c1633706c963d6 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 23 Mar 2026 02:02:18 -0400 Subject: diff-highlight: fetch all config with one process When diff-highlight was written, there was no way to fetch multiple config keys _and_ have them interpreted as colors. So we were stuck with either invoking git-config once for each config key, or fetching them all and converting human-readable color names into ANSI codes ourselves. I chose the former, but it means that diff-highlight kicks off 6 git-config processes (even if you haven't configured anything, it has to check each one). But since Git 2.18.0, we can do: git config --type=color --get-regexp=^color\.diff-highlight\. to get all of them in one shot. Note that any callers which pass in colors directly to the module via @OLD_HIGHLIGHT and @NEW_HIGHLIGHT (like diff-so-fancy plans to do) are unaffected; those colors suppress any config lookup we'd do ourselves. You can see the effect like: # diff-highlight suppresses git-config's stderr, so dump # trace through descriptor 3 git show d1f33c753d | GIT_TRACE=3 diff-highlight 3>&2 >/dev/null which drops from 6 lines down to 1. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- contrib/diff-highlight/DiffHighlight.pm | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) (limited to 'contrib/diff-highlight/DiffHighlight.pm') diff --git a/contrib/diff-highlight/DiffHighlight.pm b/contrib/diff-highlight/DiffHighlight.pm index 96369eadf9..abe457882e 100644 --- a/contrib/diff-highlight/DiffHighlight.pm +++ b/contrib/diff-highlight/DiffHighlight.pm @@ -131,9 +131,21 @@ sub highlight_stdin { # of it being used in other settings. Let's handle our own # fallback, which means we will work even if git can't be run. sub color_config { + our $cached_config; my ($key, $default) = @_; - my $s = `git config --get-color $key 2>$NULL`; - return length($s) ? $s : $default; + + if (!defined $cached_config) { + $cached_config = {}; + my $data = `git config --type=color --get-regexp '^color\.diff-highlight\.' 2>$NULL`; + for my $line (split /\n/, $data) { + my ($key, $color) = split ' ', $line, 2; + $key =~ s/^color\.diff-highlight\.// or next; + $cached_config->{$key} = $color; + } + } + + my $s = $cached_config->{$key}; + return defined($s) ? $s : $default; } sub show_hunk { @@ -172,16 +184,16 @@ sub load_color_config { # always be set if you want highlighting to do anything. if (!defined $OLD_HIGHLIGHT[1]) { @OLD_HIGHLIGHT = ( - color_config('color.diff-highlight.oldnormal'), - color_config('color.diff-highlight.oldhighlight', "\x1b[7m"), - color_config('color.diff-highlight.oldreset', "\x1b[27m") + color_config('oldnormal'), + color_config('oldhighlight', "\x1b[7m"), + color_config('oldreset', "\x1b[27m") ); } if (!defined $NEW_HIGHLIGHT[1]) { @NEW_HIGHLIGHT = ( - color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]), - color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]), - color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2]) + color_config('newnormal', $OLD_HIGHLIGHT[0]), + color_config('newhighlight', $OLD_HIGHLIGHT[1]), + color_config('newreset', $OLD_HIGHLIGHT[2]) ); }; } -- cgit v1.3-5-g9baa