From 4881e1240ccf30aa6cadeba811f7faf36e2189c5 Mon Sep 17 00:00:00 2001
From: Colin Rofls <colin@cmyr.net>
Date: Thu, 25 Jul 2024 11:16:02 -0400
Subject: [PATCH] [ttx_diff] replace difflib with cdifflib

difflib is not very efficient, and this has a significant impact on
runtime; for `NotoSansMono` I go from 18m of wall time to 13m16s.
---
 resources/scripts/requirements.txt | 1 +
 resources/scripts/ttx_diff.py      | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/resources/scripts/requirements.txt b/resources/scripts/requirements.txt
index caa419c2..b23f88ac 100644
--- a/resources/scripts/requirements.txt
+++ b/resources/scripts/requirements.txt
@@ -6,3 +6,4 @@ fontmake[repacker]==3.8.1
 # our scripts import it directly, so we list it among the top-level requirements.
 fonttools
 lxml
+cdifflib
diff --git a/resources/scripts/ttx_diff.py b/resources/scripts/ttx_diff.py
index 73ac2993..0c5db2fc 100755
--- a/resources/scripts/ttx_diff.py
+++ b/resources/scripts/ttx_diff.py
@@ -42,7 +42,7 @@
 import shutil
 import subprocess
 import sys
-from difflib import SequenceMatcher
+from cdifflib import CSequenceMatcher as SequenceMatcher
 from typing import MutableSequence