@matheusbsbs / matheus-bagliano / commits / 6689a6ea49

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 <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Mar 23, 2026 at 02:02 UTC 6689a6ea493b484d6a43601f42c1633706c963d6
1 file changed +20 -8
contrib/diff-highlight/DiffHighlight.pm
+20 -8
@@ -131,9 +131,21 @@ sub highlight_stdin {
131 # of it being used in other settings. Let's handle our own
132 # fallback, which means we will work even if git can't be run.
133 sub color_config {
134 + our $cached_config;
135 my ($key, $default) = @_;
135 - my $s = `git config --get-color $key 2>$NULL`;
136 - return length($s) ? $s : $default;
136 +
137 + if (!defined $cached_config) {
138 + $cached_config = {};
139 + my $data = `git config --type=color --get-regexp '^color\.diff-highlight\.' 2>$NULL`;
140 + for my $line (split /\n/, $data) {
141 + my ($key, $color) = split ' ', $line, 2;
142 + $key =~ s/^color\.diff-highlight\.// or next;
143 + $cached_config->{$key} = $color;
144 + }
145 + }
146 +
147 + my $s = $cached_config->{$key};
148 + return defined($s) ? $s : $default;
149 }
150
151 sub show_hunk {
@@ -172,16 +184,16 @@ sub load_color_config {
184 # always be set if you want highlighting to do anything.
185 if (!defined $OLD_HIGHLIGHT[1]) {
186 @OLD_HIGHLIGHT = (
175 - color_config('color.diff-highlight.oldnormal'),
176 - color_config('color.diff-highlight.oldhighlight', "\x1b[7m"),
177 - color_config('color.diff-highlight.oldreset', "\x1b[27m")
187 + color_config('oldnormal'),
188 + color_config('oldhighlight', "\x1b[7m"),
189 + color_config('oldreset', "\x1b[27m")
190 );
191 }
192 if (!defined $NEW_HIGHLIGHT[1]) {
193 @NEW_HIGHLIGHT = (
182 - color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]),
183 - color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]),
184 - color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2])
194 + color_config('newnormal', $OLD_HIGHLIGHT[0]),
195 + color_config('newhighlight', $OLD_HIGHLIGHT[1]),
196 + color_config('newreset', $OLD_HIGHLIGHT[2])
197 );
198 };
199 }