use pipe for git-http-backend output

This allows us to stream the output to the client without buffering
everything up-front.  Next, we'll let Danga::Socket (or AE in the
future) wait for readability.

diff --git a/lib/PublicInbox/GitHTTPBackend.pm b/lib/PublicInbox/GitHTTPBackend.pm
index 562c290e0828bc10c58a33b34d13ee708f37310d..cba025e7edcb0604bebcc03f2ad6d831c05e3c9e 100644 (file)
--- a/lib/PublicInbox/GitHTTPBackend.pm
+++ b/lib/PublicInbox/GitHTTPBackend.pm
@@ -132,9 +132,9 @@ sub serve_smart {
        my $buf;
        my $in;
        my $err = $env->{'psgi.errors'};
-       if (fileno($input) >= 0) { # FIXME untested
+       if (fileno($input) >= 0) {
                $in = $input;
-       } else {
+       } else { # FIXME untested
                $in = IO::File->new_tmpfile;
                while (1) {
                        my $r = $input->read($buf, 8192);
@@ -148,7 +148,11 @@ sub serve_smart {
                $in->flush;
                $in->sysseek(0, SEEK_SET);
        }
-       my $out = IO::File->new_tmpfile;
+       my ($rpipe, $wpipe);
+       unless (pipe($rpipe, $wpipe)) {
+               $err->print('error creating pipe', $!, "\n");
+               return r(500);
+       }
        my $pid = fork; # TODO: vfork under Linux...
        unless (defined $pid) {
                $err->print('error forking: ', $!, "\n");
@@ -170,22 +174,17 @@ sub serve_smart {
                $ENV{GIT_HTTP_EXPORT_ALL} = '1';
                $ENV{PATH_TRANSLATED} = "$git->{git_dir}/$path";
                dup2(fileno($in), 0) or die "redirect stdin failed: $!\n";
-               dup2(fileno($out), 1) or die "redirect stdout failed: $!\n";
+               dup2(fileno($wpipe), 1) or die "redirect stdout failed: $!\n";
                my @cmd = qw(git http-backend);
                exec(@cmd) or die 'exec `' . join(' ', @cmd). "' failed: $!\n";
        }
-
-       if (waitpid($pid, 0) != $pid) {
-               $err->print("git http-backend ($git->{git_dir}): ", $?, "\n");
-               return r(500);
-       }
+       $wpipe = undef;
        $in = undef;
-       $out->seek(0, SEEK_SET);
        my @h;
        my $code = 200;
        {
                local $/ = "\r\n";
-               while (defined(my $line = <$out>)) {
+               while (defined(my $line = <$rpipe>)) {
                        if ($line =~ /\AStatus:\s*(\d+)/) {
                                $code = $1;
                        } else {
@@ -200,7 +199,7 @@ sub serve_smart {
                my ($cb) = @_;
                my $fh = $cb->([ $code, \@h ]);
                while (1) {
-                       my $r = $out->read($buf, 8192);
+                       my $r = sysread($rpipe, $buf, 8192);
                        die "$!\n" unless defined $r;
                        last if ($r == 0);
                        $fh->write($buf);