diff-highlight: allow module callers to pass in color config
Users of the module may want to pass in their own color config for a few obvious reasons: - they are pulling the config from different variables than diff-highlight itself uses - they are loading the config in a more efficient way (say, by parsing git-config --list) and don't want to incur the six (!) git-config calls that DiffHighlight.pm runs to check all config Let's allow users of the module to pass in the color config, and lazy-load it when needed if they haven't. Signed-off-by: Scott Baker <scott@perturb.org> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Scott Baker committed
Mar 23, 2026 at 02:02 UTC
bd958e91dffdba00ef94dc9bfc04b46599362f9a
2 files changed
+35
-12
contrib/diff-highlight/DiffHighlight.pm
+29
-12
@@ -9,18 +9,11 @@ use File::Spec;
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my $NULL = File::Spec->devnull();
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-# Highlight by reversing foreground and background. You could do
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-# other things like bold or underline if you prefer.
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-my @OLD_HIGHLIGHT = (
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- color_config('color.diff-highlight.oldnormal'),
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- color_config('color.diff-highlight.oldhighlight', "\x1b[7m"),
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- color_config('color.diff-highlight.oldreset', "\x1b[27m")
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-);
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-my @NEW_HIGHLIGHT = (
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- color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]),
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- color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]),
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- color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2])
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-);
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+# The color theme is initially set to nothing here to allow outside callers
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+# to set the colors for their application. If nothing is sent in we use
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+# colors from git config in load_color_config().
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+our @OLD_HIGHLIGHT = ();
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+our @NEW_HIGHLIGHT = ();
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my $RESET = "\x1b[m";
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my $COLOR = qr/\x1b\[[0-9;]*m/;
@@ -170,6 +163,29 @@ sub show_hunk {
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$line_cb->(@queue);
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}
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+sub load_color_config {
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+ # If the colors were NOT set from outside this module we load them on-demand
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+ # from the git config. Note that only one of elements 0 and 2 in each
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+ # array is used (depending on whether you are doing set/unset on an
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+ # attribute, or specifying normal vs highlighted coloring). So we use
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+ # element 1 as our check for whether colors were passed in; it should
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+ # always be set if you want highlighting to do anything.
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+ if (!defined $OLD_HIGHLIGHT[1]) {
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+ @OLD_HIGHLIGHT = (
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+ color_config('color.diff-highlight.oldnormal'),
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+ color_config('color.diff-highlight.oldhighlight', "\x1b[7m"),
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+ color_config('color.diff-highlight.oldreset', "\x1b[27m")
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+ );
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+ }
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+ if (!defined $NEW_HIGHLIGHT[1]) {
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+ @NEW_HIGHLIGHT = (
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+ color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]),
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+ color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]),
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+ color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2])
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+ );
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+ };
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+}
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+
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sub highlight_pair {
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my @a = split_line(shift);
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my @b = split_line(shift);
@@ -218,6 +234,7 @@ sub highlight_pair {
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}
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if (is_pair_interesting(\@a, $pa, $sa, \@b, $pb, $sb)) {
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+ load_color_config();
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return highlight_line(\@a, $pa, $sa, \@OLD_HIGHLIGHT),
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highlight_line(\@b, $pb, $sb, \@NEW_HIGHLIGHT);
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}
contrib/diff-highlight/README
+6
@@ -138,6 +138,12 @@ Your script may set up one or more of the following variables:
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processing a logical chunk of input). The default function flushes
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stdout.
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+ - @DiffHighlight::OLD_HIGHLIGHT and @DiffHighlight::NEW_HIGHLIGHT - these
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+ arrays specify the normal, highlighted, and reset colors (in that order)
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+ for old/new lines. If unset, values will be retrieved by calling `git
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+ config` (see "Color Config" above). Note that these should be the literal
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+ color bytes (starting with an ANSI escape code), not color names.
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+
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The script may then feed lines, one at a time, to DiffHighlight::handle_line().
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When lines are done processing, they will be fed to $line_cb. Note that
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DiffHighlight may queue up many input lines (to analyze a whole hunk)