repobrowse: port patch generation over to qspawn

And start generalizing the qspawn usage code for PSGI
with psgi_return.

2 files changed, 69 insertions, 49 deletions

diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index 697c55a1..099c1f34 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -9,6 +9,7 @@ package PublicInbox::Qspawn;
 use strict;
 use warnings;
 use PublicInbox::Spawn qw(popen_rd);
+my $def_limiter;
 
 sub new ($$$;) {
         my ($class, $cmd, $env, $opt) = @_;
@@ -54,6 +55,63 @@ sub start {
         }
 }
 
+sub psgi_return {
+        my ($self, $env, $limiter, $parse_hdr) = @_;
+        my ($fh, $rpipe);
+        my $end = sub {
+                if (my $err = $self->finish) {
+                        $err = join(' ', @{$self->{args}->{cmd}}).": $err\n";
+                        $env->{'psgi.errors'}->print($err);
+                }
+                $fh->close if $fh; # async-only
+        };
+
+        # Danga::Socket users, we queue up the read_enable callback to
+        # fire after pending writes are complete:
+        my $buf = '';
+        my $rd_hdr = sub {
+                my $r = sysread($rpipe, $buf, 1024, length($buf));
+                return if !defined($r) && ($!{EINTR} || $!{EAGAIN});
+                $parse_hdr->($r, $buf);
+        };
+        my $res;
+        my $async = $env->{'pi-httpd.async'};
+        my $cb = sub {
+                my $r = $rd_hdr->() or return;
+                $rd_hdr = undef;
+                if (scalar(@$r) == 3) { # error
+                        if ($async) {
+                                $async->close; # calls rpipe->close
+                        } else {
+                                $rpipe->close;
+                                $end->();
+                        }
+                        $res->($r);
+                } elsif ($async) {
+                        $fh = $res->($r); # scalar @$r == 2
+                        $async->async_pass($env->{'psgix.io'}, $fh, \$buf);
+                } else { # for synchronous PSGI servers
+                        require PublicInbox::GetlineBody;
+                        $r->[2] = PublicInbox::GetlineBody->new($rpipe, $end,
+                                                                $buf);
+                        $res->($r);
+                }
+        };
+        $limiter ||= $def_limiter ||= PublicInbox::Qspawn::Limiter->new(32);
+        sub {
+                ($res) = @_;
+                $self->start($limiter, sub { # may run later, much later...
+                        ($rpipe) = @_;
+                        if ($async) {
+                        # PublicInbox::HTTPD::Async->new($rpipe, $cb, $end)
+                                $async = $async->($rpipe, $cb, $end);
+                        } else { # generic PSGI
+                                $cb->() while $rd_hdr;
+                        }
+                });
+        };
+}
+
 package PublicInbox::Qspawn::Limiter;
 use strict;
 use warnings;
diff --git a/lib/PublicInbox/RepobrowseGitPatch.pm b/lib/PublicInbox/RepobrowseGitPatch.pm
index eeffc5cb..e8820f72 100644
--- a/lib/PublicInbox/RepobrowseGitPatch.pm
+++ b/lib/PublicInbox/RepobrowseGitPatch.pm
@@ -7,6 +7,7 @@ package PublicInbox::RepobrowseGitPatch;
 use strict;
 use warnings;
 use base qw(PublicInbox::RepobrowseBase);
+use PublicInbox::Qspawn;
 
 # try to be educational and show the command-line used in the signature
 my @CMD = qw(format-patch -M --stdout);
@@ -23,58 +24,19 @@ sub call_git_patch {
         # limit scope, don't take extra args to avoid wasting server
         # resources buffering:
         my $range = "$id~1..$id^0";
-        my @cmd = (@CMD, $sig." $range", $range, '--');
+        my @cmd = ('git', "--git-dir=$git->{git_dir}", @CMD,
+                        $sig." $range", $range, '--');
         if (defined(my $expath = $req->{expath})) {
-                push @cmd, $expath;
+                push @cmd, $expath if $expath ne '';
         }
-        my $rpipe = $git->popen(@cmd);
-        my $err = $env->{'psgi.errors'};
-        my ($n, $res, $vin, $fh);
-        my $end = sub {
-                if ($fh) {
-                        $fh->close;
-                        $fh = undef;
-                } elsif ($res) {
-                        $res->($self->r(500));
-                }
-                if ($rpipe) {
-                        $rpipe->close; # _may_ be Danga::Socket::close
-                        $rpipe = undef;
-                }
-        };
-        my $fail = sub {
-                if ($!{EAGAIN} || $!{EINTR}) {
-                        select($vin, undef, undef, undef) if defined $vin;
-                        # $vin is undef on async, so this is a noop on EAGAIN
-                        return;
-                }
-                my $e = $!;
-                $end->();
-                $err->print("git format-patch ($git->{git_dir}): $e\n");
-        };
-        my $cb = sub {
-                $n = $rpipe->sysread(my $buf, 65536);
-                return $fail->() unless defined $n;
-                return $end->() if $n == 0;
-                if ($res) {
-                        my $h = ['Content-Type', 'text/plain; charset=UTF-8'];
-                        $fh = $res->([200, $h]);
-                        $res = undef;
-                }
-                $fh->write($buf);
-        };
 
-        if (my $async = $env->{'pi-httpd.async'}) {
-                $rpipe = $async->($rpipe, $cb);
-                sub { ($res) = @_ } # let Danga::Socket handle the rest.
-        } else { # synchronous loop for other PSGI servers
-                $vin = '';
-                vec($vin, fileno($rpipe), 1) = 1;
-                sub {
-                        ($res) = @_;
-                        while ($rpipe) { $cb->() }
-                }
-        }
+        # FIXME: generalize this with other qspawn users
+        my $qsp = PublicInbox::Qspawn->new(\@cmd);
+        $qsp->psgi_return($env, undef, sub {
+                my ($r) = @_;
+                my $h = ['Content-Type', 'text/plain; charset=UTF-8'];
+                $r ? [ 200, $h ] : [ 500, $h, [ "format-patch error\n" ] ];
+        });
 }
 
 1;