From 33362430ea03e5877ce1d17bbe1da830dcebea3e Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Wed, 11 Jan 2017 04:12:26 +0000
Subject: repobrowse: qspawn + streaming for git commit display

This prevents "git show" processes from monopolizing
the system and allows us to better handle backpressure
from gigantic commits.
---
 lib/PublicInbox/Qspawn.pm | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

(limited to 'lib/PublicInbox/Qspawn.pm')

diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index cd1079a0..eead5a5b 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -9,6 +9,7 @@ package PublicInbox::Qspawn;
 use strict;
 use warnings;
 use PublicInbox::Spawn qw(popen_rd);
+require Plack::Util;
 my $def_limiter;
 
 sub new ($$$;) {
@@ -60,11 +61,25 @@ sub start {
 	}
 }
 
+# create a filter for "push"-based streaming PSGI writes used by HTTPD::Async
+sub filter_fh ($$) {
+	my ($fh, $filter) = @_;
+	Plack::Util::inline_object(
+		close => sub {
+			$fh->write($filter->(undef));
+			$fh->close;
+		},
+		write => sub {
+			$fh->write($filter->($_[0]));
+		});
+}
+
 sub psgi_return {
 	my ($self, $env, $limiter, $parse_hdr) = @_;
 	my ($fh, $rpipe);
 	my $end = sub {
-		if (my $err = $self->finish) {
+		my $err = $self->finish;
+		if ($err && !$env->{'qspawn.quiet'}) {
 			$err = join(' ', @{$self->{args}->[0]}).": $err\n";
 			$env->{'psgi.errors'}->print($err);
 		}
@@ -84,6 +99,7 @@ sub psgi_return {
 	my $cb = sub {
 		my $r = $rd_hdr->() or return;
 		$rd_hdr = undef;
+		my $filter = delete $env->{'qspawn.filter'};
 		if (scalar(@$r) == 3) { # error
 			if ($async) {
 				$async->close; # calls rpipe->close
@@ -94,11 +110,12 @@ sub psgi_return {
 			$res->($r);
 		} elsif ($async) {
 			$fh = $res->($r); # scalar @$r == 2
+			$fh = filter_fh($fh, $filter) if $filter;
 			$async->async_pass($env->{'psgix.io'}, $fh, \$buf);
 		} else { # for synchronous PSGI servers
 			require PublicInbox::GetlineBody;
 			$r->[2] = PublicInbox::GetlineBody->new($rpipe, $end,
-								$buf);
+								$buf, $filter);
 			$res->($r);
 		}
 	};
-- 
cgit v1.2.3-24-ge0c7