From 84155e2ebd54bd2dd07d1a920894496db75707c1 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Sun, 7 Nov 2021 05:36:31 +0100
Subject: [PATCH] index: retrieve git log from cached text include

While git is fast, it still results in a ~50ms command for an otherwise
static ~5ms landing page.  Run `make -B UPDATE` as post-commit git hook
(and post-rewrite, and post-checkout) on live checkouts.
---
 .gitignore | 1 +
 Makefile   | 5 ++++-
 index.plp  | 4 ++--
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index d579771..142f46a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 # derived contents
 /sitemap.xml
 /light.css
+/UPDATE
 /plan.plp
 /word/*.min.js
 
diff --git a/Makefile b/Makefile
index e635f5f..aaf9283 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-all: sitemap.xml light.css plan.plp data/digraphs.inc.pl data/unicode-cover.inc.pl data/countries.inc.pl data/browser data/termcol-xcolor.inc.pl data/digraphs-xorg.inc.pl word
+all: sitemap.xml light.css plan.plp UPDATE data/digraphs.inc.pl data/unicode-cover.inc.pl data/countries.inc.pl data/browser data/termcol-xcolor.inc.pl data/digraphs-xorg.inc.pl word
 more: all
 
 .PHONY: force # applied to download after 2 hours
@@ -20,6 +20,9 @@ light.css: tools/stripcss base.css
 plan.plp: TODO
 	kramdown $< >$@
 
+UPDATE: $(download)
+	$(call cmdsave,git log -1 --date=short --pretty="%ad	%s")
+
 word: word/put.min.js data/wordlist.en.json data/wordlist.nl.json data/wordlist.ru.json data/wordpairs.json
 
 word/put.js: $(download)
diff --git a/index.plp b/index.plp
index c2e939b..468e927 100644
--- a/index.plp
+++ b/index.plp
@@ -15,6 +15,7 @@ Html({
 		' title="RSS feed of repository updates"',
 		' href="http://git.shiar.nl/sheet.git/rss">',
 	],
+	data => ['UPDATE'],
 });
 
 :>
@@ -28,8 +29,7 @@ Originally created by Mischa <span class="family-name">Poslawsky</span>,
 but you're free to use, print, alter, and redistribute under the AGPL license.
 </p>
 <:
-my @format = ('--date=short', "--pretty=%ad (%ar)\t%s");
-if (open my $log, '-|', git => 'log', -1, @format) {{
+if (open my $log, '<', 'UPDATE') {{
 	my $line = readline $log;
 	$line or next;  # explicitly ignore empty input
 	EscapeHTML $line;
-- 
2.30.0