+sub rd_hdr ($) {
+ my ($self) = @_;
+ # typically used for reading CGI headers
+ # We also need to check EINTR for generic PSGI servers.
+ my $ret;
+ my $total_rd = 0;
+ my $hdr_buf = $self->{hdr_buf};
+ my ($ph_cb, $ph_arg) = @{$self->{parse_hdr}};
+ do {
+ my $r = sysread($self->{rpipe}, $$hdr_buf, 4096,
+ length($$hdr_buf));
+ if (defined($r)) {
+ $total_rd += $r;
+ eval { $ret = $ph_cb->($total_rd, $hdr_buf, $ph_arg) };
+ if ($@) {
+ warn "parse_hdr: $@";
+ $ret = [ 500, [], [ "Internal error\n" ] ];
+ }
+ } else {
+ # caller should notify us when it's ready:
+ return if $! == EAGAIN;
+ next if $! == EINTR; # immediate retry
+ warn "error reading header: $!";
+ $ret = [ 500, [], [ "Internal error\n" ] ];
+ }
+ } until (defined $ret);
+ delete $self->{parse_hdr}; # done parsing headers
+ $ret;
+}
+
+sub psgi_return_init_cb {
+ my ($self) = @_;
+ my $r = rd_hdr($self) or return;
+ my $env = $self->{psgi_env};
+ my $filter = delete $env->{'qspawn.filter'} //
+ PublicInbox::GzipFilter::qsp_maybe($r->[1], $env);
+
+ my $wcb = delete $env->{'qspawn.wcb'};
+ my $async = delete $self->{async};
+ if (scalar(@$r) == 3) { # error
+ if ($async) {
+ # calls rpipe->close && ->event_step
+ $async->close;
+ } else {
+ $self->{rpipe}->close;
+ event_step($self);
+ }
+ $wcb->($r);
+ } elsif ($async) {
+ # done reading headers, handoff to read body
+ my $fh = $wcb->($r); # scalar @$r == 2
+ $fh = $filter->attach($fh) if $filter;
+ $self->{fh} = $fh;
+ $async->async_pass($env->{'psgix.io'}, $fh,
+ delete($self->{hdr_buf}));
+ } else { # for synchronous PSGI servers
+ require PublicInbox::GetlineBody;
+ $r->[2] = PublicInbox::GetlineBody->new($self->{rpipe},
+ \&event_step, $self,
+ ${$self->{hdr_buf}}, $filter);
+ $wcb->($r);
+ }
+}
+
+sub psgi_return_start { # may run later, much later...
+ my ($self) = @_;
+ if (my $async = $self->{psgi_env}->{'pi-httpd.async'}) {
+ # PublicInbox::HTTPD::Async->new(rpipe, $cb, $cb_arg, $end_obj)
+ $self->{async} = $async->($self->{rpipe},
+ \&psgi_return_init_cb, $self, $self);
+ } else { # generic PSGI
+ psgi_return_init_cb($self) while $self->{parse_hdr};
+ }
+}
+