git-http-backend: start async API for streaming

[public-inbox.git] / lib / PublicInbox / GitHTTPBackend.pm

diff --git a/lib/PublicInbox/GitHTTPBackend.pm b/lib/PublicInbox/GitHTTPBackend.pm
index 3cf78579ba80d59ad273444d98b5747bae708d69..9c32535bb70ad414195017729e73fd448d84054e 100644 (file)
--- a/lib/PublicInbox/GitHTTPBackend.pm
+++ b/lib/PublicInbox/GitHTTPBackend.pm
@@ -158,6 +158,7 @@ sub serve_smart {
                $err->print('error forking: ', $!, "\n");
                return r(500);
        }
+       my $git_dir = $git->{git_dir};
        if ($pid == 0) {
                # GIT_HTTP_EXPORT_ALL, GIT_COMMITTER_NAME, GIT_COMMITTER_EMAIL
                # may be set in the server-process and are passed as-is
@@ -172,36 +173,47 @@ sub serve_smart {
                }
                # $ENV{GIT_PROJECT_ROOT} = $git->{git_dir};
                $ENV{GIT_HTTP_EXPORT_ALL} = '1';
-               $ENV{PATH_TRANSLATED} = "$git->{git_dir}/$path";
+               $ENV{PATH_TRANSLATED} = "$git_dir/$path";
                dup2(fileno($in), 0) or die "redirect stdin 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";
        }
        $wpipe = $in = undef;
-       $rpipe->blocking(0);
        $buf = '';
-       my $vin;
-       vec($vin, fileno($rpipe), 1) = 1;
-       my ($fh, $res);
-       my $fail = sub {
-               my ($e) = @_;
-               if ($e eq 'EAGAIN') {
-                       select($vin, undef, undef, undef);
+       my ($vin, $fh, $res);
+       my $end = sub {
+               if ($fh) {
+                       $fh->close;
+                       $fh = undef;
                } else {
+                       $res->(r(500)) if $res;
+               }
+               if ($rpipe) {
+                       $rpipe->close; # _may_ be Danga::Socket::close
                        $rpipe = undef;
-                       $fh->close if $fh;
-                       $err->print('git http-backend error: ', $e, "\n");
+               }
+               if (defined $pid) {
+                       my $wpid = $pid;
+                       $pid = undef;
+                       return if $wpid == waitpid($wpid, 0);
+                       $err->print("git http-backend ($git_dir): $?\n");
                }
        };
-       my $cb = sub {
-               my $r = sysread($rpipe, $buf, 8192, length($buf));
-               return $fail->($!{EAGAIN} ? 'EAGAIN' : $!) unless defined $r;
-               if ($r == 0) { # EOF
-                       $rpipe = undef;
-                       $fh->close if $fh;
+       my $fail = sub {
+               my ($e) = @_;
+               if ($e eq 'EAGAIN') {
+                       select($vin, undef, undef, undef) if defined $vin;
+                       # $vin is undef on async, so this is a noop on EAGAIN
                        return;
                }
+               $end->();
+               $err->print("git http-backend ($git_dir): $e\n");
+       };
+       my $cb = sub { # read git-http-backend output and stream to client
+               my $r = $rpipe ? $rpipe->sysread($buf, 8192, length($buf)) : 0;
+               return $fail->($!{EAGAIN} ? 'EAGAIN' : $!) unless defined $r;
+               return $end->() if $r == 0; # EOF
                if ($fh) { # stream body from git-http-backend to HTTP client
                        $fh->write($buf);
                        $buf = '';
@@ -219,14 +231,22 @@ sub serve_smart {
                        }
                        # write response header:
                        $fh = $res->([ $code, \@h ]);
+                       $res = undef;
                        $fh->write($buf);
                        $buf = '';
                } # else { keep reading ... }
        };
-       sub {
-               ($res) = @_;
-               while ($rpipe) { $cb->() }
-       };
+       if (my $async = $env->{'pi-httpd.async'}) {
+               $rpipe = $async->($rpipe, $cb);
+               sub { ($res) = @_ } # let Danga::Socket handle the rest.
+       } else { # synchronous loop
+               $vin = '';
+               vec($vin, fileno($rpipe), 1) = 1;
+               sub {
+                       ($res) = @_;
+                       while ($rpipe) { $cb->() }
+               }
+       }
 }
 
 1;