X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FGetlineBody.pm;h=92719a8255c56f46fcf9312ac7c669a6f64104da;hb=95bdac7f09c69036efed537a4d03d5bdd2ae4eb6;hp=4f8765bbe6e7bfd37d67f23a7343fe99535b389a;hpb=79e11eea11dd561301a05c42ba824a7d352bd398;p=public-inbox.git

diff --git a/lib/PublicInbox/GetlineBody.pm b/lib/PublicInbox/GetlineBody.pm
index 4f8765bb..92719a82 100644
--- a/lib/PublicInbox/GetlineBody.pm
+++ b/lib/PublicInbox/GetlineBody.pm
@@ -1,31 +1,49 @@
-# Copyright (C) 2016 all contributors <meta@public-inbox.org>
+# Copyright (C) 2016-2020 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # Wrap a pipe or file for PSGI streaming response bodies and calls the
 # end callback when the object goes out-of-scope.
 # This depends on rpipe being _blocking_ on getline.
+#
+# public-inbox-httpd favors "getline" response bodies to take a
+# "pull"-based approach to feeding slow clients (as opposed to a
+# more common "push" model)
 package PublicInbox::GetlineBody;
 use strict;
 use warnings;
 
 sub new {
-	my ($class, $rpipe, $end, $buf) = @_;
-	bless { rpipe => $rpipe, end => $end, buf => $buf }, $class;
+	my ($class, $rpipe, $end, $end_arg, $buf) = @_;
+	bless {
+		rpipe => $rpipe,
+		end => $end,
+		end_arg => $end_arg,
+		buf => $buf,
+		filter => 0,
+	}, $class;
 }
 
+# close should always be called after getline returns undef,
+# but a client aborting a connection can ruin our day; so lets
+# hope our underlying PSGI server does not leak references, here.
 sub DESTROY { $_[0]->close }
 
 sub getline {
 	my ($self) = @_;
-	my $buf = delete $self->{buf};
-	defined $buf ? $buf : $self->{rpipe}->getline;
+	my $filter = $self->{filter};
+	return if $filter == -1; # last call was EOF
+
+	my $buf = delete $self->{buf}; # initial buffer
+	$buf = $self->{rpipe}->getline unless defined $buf;
+	$self->{filter} = -1 unless defined $buf; # set EOF for next call
+	$buf;
 }
 
 sub close {
 	my ($self) = @_;
-	delete $self->{rpipe};
-	my $end = delete $self->{end} or return;
-	$end->();
+	my ($rpipe, $end, $end_arg) = delete @$self{qw(rpipe end end_arg)};
+	close $rpipe if $rpipe;
+	$end->($end_arg) if $end;
 }
 
 1;