From: Eric Wong <e@80x24.org>
Date: Thu, 4 Jul 2024 02:20:55 +0000 (+0000)
Subject: http: don't requeue if using write buffer
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=112fbeed50629c2b366db24e5ccb70103b759821;p=thirdparty%2Fpublic-inbox.git

http: don't requeue if using write buffer

The write buffering will already be processed inside
->event_step, so requeue will cause a needless read(2) outside
of epoll_wait/kevent(2) readiness notifications.

This ought to avoid problems in case of pipelined connections,
but those aren't possible behind a reverse proxy and AFAIK most
HTTP clients don't do pipelining.  This bug was only noticed via
strace while searching for extra syscalls, and not from
real-world use.
---

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 4ccb1b817..88cab5447 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -247,7 +247,8 @@ sub response_done {
 	delete $self->{env}; # we're no longer busy
 	# HEAD requests set $alive = 3 so we don't send "0\r\n\r\n";
 	$self->write(\"0\r\n\r\n") if $alive == 2;
-	$self->write($alive ? $self->can('requeue') : \&close);
+	$self->write(\&close) if !$alive;
+	$self->requeue if $alive && !$self->{wbuf};
 }
 
 sub getline_pull {
@@ -280,7 +281,7 @@ sub getline_pull {
 		}
 	} elsif ($@) {
 		warn "response ->getline error: $@";
-		$self->close;
+		return $self->close;
 	}
 	response_done($self, delete $self->{alive});
 }