From: Eric Wong <e@80x24.org>
Date: Sun, 7 Jul 2024 05:57:26 +0000 (+0000)
Subject: www: manifest.js.gz handles If-Modified-Since
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35433a5f4a50ae855c4dc807eda708e15ef1812a;p=thirdparty%2Fpublic-inbox.git

www: manifest.js.gz handles If-Modified-Since

While we can't avoid the expensive manifest.js.gz generation,
non-Varnish users now get the bandwidth savings from seeing a
304 response.  This has no effect on Varnish users since Varnish
will forward the request to us without If-Modified-Since if it
gets a cache miss, and handle 304 for us on cache hits.
---

diff --git a/lib/PublicInbox/ManifestJsGz.pm b/lib/PublicInbox/ManifestJsGz.pm
index be5d5f2af..f912f8123 100644
--- a/lib/PublicInbox/ManifestJsGz.pm
+++ b/lib/PublicInbox/ManifestJsGz.pm
@@ -107,8 +107,12 @@ sub psgi_triple {
 	}
 	$manifest = $json->encode($manifest);
 	gzip(\$manifest => \(my $out));
+	my $mtime = time2str($ctx->{-mtime});
+	if (my $ims = $ctx->{env}->{HTTP_IF_MODIFIED_SINCE}) {
+		return [ 304, [], [] ] if $mtime eq $ims;
+	}
 	[ 200, [ qw(Content-Type application/gzip),
-		 'Last-Modified', time2str($ctx->{-mtime}),
+		 'Last-Modified', $mtime,
 		 'Content-Length', length($out) ], [ $out ] ]
 }
 
diff --git a/t/www_listing.t b/t/www_listing.t
index 0a4c79e8f..5bca45706 100644
--- a/t/www_listing.t
+++ b/t/www_listing.t
@@ -6,7 +6,7 @@ use v5.12; use PublicInbox::TestCommon;
 use PublicInbox::Import;
 use IO::Uncompress::Gunzip qw(gunzip);
 require_mods(qw(json URI::Escape Plack::Builder HTTP::Tiny));
-require_cmd 'curl';
+my $curl = require_cmd 'curl';
 require PublicInbox::WwwListing;
 require PublicInbox::ManifestJsGz;
 use PublicInbox::Config;
@@ -177,6 +177,15 @@ EOM
 
 	$td = start_script($cmd, $env, { 3 => $sock });
 
+	my $local_mfest = "$tmpdir/local.manifest.js.gz";
+	xsys_e [$curl, '-gsSfR', '-o', $local_mfest,
+		"http://$host:$port/manifest.js.gz" ];
+	xsys_e [$curl, '-vgsSfR', '-o', "$tmpdir/again.js.gz",
+		'-z', $local_mfest, "http://$host:$port/manifest.js.gz" ],
+		undef, { 2 => \(my $curl_err) };
+	like $curl_err, qr! HTTP/1\.[012] 304 !sm,
+		'got 304 response w/ If-Modified-Since';
+
 	# default publicinboxGrokManifest match=domain default
 	tiny_test($json, $host, $port);