[PATCH 2/4] httpd/async: retry reads properly when parsing headers

[Eric Wong <e@80x24.org>]

While git-http-backend sends headers with one write syscall,
upstream cgit still trickles them out line-by-line and we need to
account for that and retry Qspawn {parse_hdr} callbacks.
---
 lib/PublicInbox/HTTPD/Async.pm | 8 +++++---
 lib/PublicInbox/Qspawn.pm      | 4 ++--
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/PublicInbox/HTTPD/Async.pm b/lib/PublicInbox/HTTPD/Async.pm
index e03daafa..7bbab1e1 100644
--- a/lib/PublicInbox/HTTPD/Async.pm
+++ b/lib/PublicInbox/HTTPD/Async.pm
@@ -14,7 +14,7 @@
 # arg: arg for {cb}
 # end_obj: CODE or object which responds to ->event_step when ->close is called
 package PublicInbox::HTTPD::Async;
-use strict;
+use v5.12;
 use parent qw(PublicInbox::DS);
 use Errno qw(EAGAIN);
 use PublicInbox::Syscall qw(EPOLLIN);
@@ -44,9 +44,9 @@ sub new {
 
 sub event_step {
 	my ($self) = @_;
-	if (my $cb = delete $self->{cb}) {
+	if (defined $self->{cb}) {
 		# this may call async_pass when headers are done
-		$cb->(my $refcnt_guard = delete $self->{arg});
+		$self->{cb}->($self->{arg});
 	} elsif (my $sock = $self->{sock}) {
 		# $http may be undef if discarding body output from cgit on 404
 		my $http = $self->{http} or return $self->close;
@@ -76,6 +76,7 @@ sub event_step {
 # may be PublicInbox::GzipFilter or $PublicInbox::Qspawn::qx_fh
 sub async_pass {
 	my ($self, $http, $ofh, $bref) = @_;
+	delete @$self{qw(cb arg)};
 	# In case the client HTTP connection ($http) dies, it
 	# will automatically close this ($self) object.
 	$http->{forward} = $self;
@@ -94,6 +95,7 @@ sub async_pass {
 sub close {
 	my $self = $_[0];
 	$self->SUPER::close; # DS::close
+	delete @$self{qw(cb arg)};
 
 	# we defer this to the next timer loop since close is deferred
 	if (my $end_obj = delete $self->{end_obj}) {
diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index f8cbffcb..7984e35a 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -134,7 +134,7 @@ sub start ($$$) {
 	}
 }
 
-sub psgi_qx_init_cb {
+sub psgi_qx_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
 	my ($self) = @_;
 	my $async = delete $self->{async}; # PublicInbox::HTTPD::Async
 	my ($r, $buf);
@@ -223,7 +223,7 @@ sub rd_hdr ($) {
 	$ret;
 }
 
-sub psgi_return_init_cb {
+sub psgi_return_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
 	my ($self) = @_;
 	my $r = rd_hdr($self) or return;
 	my $env = $self->{psgi_env};