qspawn: reinstate filter support, add gzip filter

We'll be supporting gzipped from sqlite3(1) dumps
for altid files in future commits.

In the future (and if we survive), we may replace
Plack::Middleware::Deflater with our own GzipFilter to work
better with asynchronous responses without relying on
memory-intensive anonymous subs.

3 files changed, 71 insertions, 0 deletions

diff --git a/t/gzip_filter.t b/t/gzip_filter.t
new file mode 100644
index 00000000..400214e6
--- /dev/null
+++ b/t/gzip_filter.t
@@ -0,0 +1,37 @@
+# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use Test::More;
+use IO::Handle (); # autoflush
+use Fcntl qw(SEEK_SET);
+use PublicInbox::TestCommon;
+require_mods(qw(Compress::Zlib IO::Uncompress::Gunzip));
+require_ok 'PublicInbox::GzipFilter';
+
+{
+        open my $fh, '+>', undef or die "open: $!";
+        open my $dup, '>&', $fh or die "dup $!";
+        $dup->autoflush(1);
+        my $filter = PublicInbox::GzipFilter->new->attach($dup);
+        ok($filter->write("hello"), 'wrote something');
+        ok($filter->write("world"), 'wrote more');
+        $filter->close;
+        seek($fh, 0, SEEK_SET) or die;
+        IO::Uncompress::Gunzip::gunzip($fh => \(my $buf));
+        is($buf, 'helloworld', 'buffer matches');
+}
+
+{
+        pipe(my ($r, $w)) or die "pipe: $!";
+        $w->autoflush(1);
+        close $r or die;
+        my $filter = PublicInbox::GzipFilter->new->attach($w);
+        my $sigpipe;
+        local $SIG{PIPE} = sub { $sigpipe = 1 };
+        open my $fh, '<', 'COPYING' or die "open(COPYING): $!";
+        my $buf = do { local $/; <$fh> };
+        while ($filter->write($buf .= rand)) {}
+        ok($sigpipe, 'got SIGPIPE');
+        close $w;
+}
+done_testing;
diff --git a/t/httpd-corner.psgi b/t/httpd-corner.psgi
index 35d1216e..f2427234 100644
--- a/t/httpd-corner.psgi
+++ b/t/httpd-corner.psgi
@@ -85,6 +85,15 @@ my $app = sub {
                         close $null;
                         [ 200, [ qw(Content-Type application/octet-stream) ]];
                 });
+        } elsif ($path eq '/psgi-return-gzip') {
+                require PublicInbox::Qspawn;
+                require PublicInbox::GzipFilter;
+                my $cmd = [qw(echo hello world)];
+                my $qsp = PublicInbox::Qspawn->new($cmd);
+                $env->{'qspawn.filter'} = PublicInbox::GzipFilter->new;
+                return $qsp->psgi_return($env, undef, sub {
+                        [ 200, [ qw(Content-Type application/octet-stream)]]
+                });
         } elsif ($path eq '/pid') {
                 $code = 200;
                 push @$body, "$$\n";
diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index c99e5ec7..e50aa436 100644
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -22,6 +22,7 @@ my $err = "$tmpdir/stderr.log";
 my $out = "$tmpdir/stdout.log";
 my $psgi = "./t/httpd-corner.psgi";
 my $sock = tcp_server() or die;
+my @zmods = qw(PublicInbox::GzipFilter IO::Uncompress::Gunzip);
 
 # make sure stdin is not a pipe for lsof test to check for leaking pipes
 open(STDIN, '<', '/dev/null') or die 'no /dev/null: $!';
@@ -324,6 +325,14 @@ SKIP: {
         close $fh or die "curl errored out \$?=$?";
         is($n, 30 * 1024 * 1024, 'got expected output from curl');
         is($non_zero, 0, 'read all zeros');
+
+        require_mods(@zmods, 1);
+        open $fh, '-|', qw(curl -sS), "$base/psgi-return-gzip" or die;
+        binmode $fh;
+        my $buf = do { local $/; <$fh> };
+        close $fh or die "curl errored out \$?=$?";
+        IO::Uncompress::Gunzip::gunzip(\$buf => \(my $out));
+        is($out, "hello world\n");
 }
 
 {
@@ -596,6 +605,22 @@ SKIP: {
         is_deeply([], [keys %child], 'no extra pipes with -W0');
 };
 
+# ensure compatibility with other PSGI servers
+SKIP: {
+        require_mods(@zmods, qw(Plack::Test HTTP::Request::Common), 3);
+        use_ok 'HTTP::Request::Common';
+        use_ok 'Plack::Test';
+        my $app = require $psgi;
+        test_psgi($app, sub {
+                my ($cb) = @_;
+                my $req = GET('http://example.com/psgi-return-gzip');
+                my $res = $cb->($req);
+                my $buf = $res->content;
+                IO::Uncompress::Gunzip::gunzip(\$buf => \(my $out));
+                is($out, "hello world\n");
+        });
+}
+
 done_testing();
 
 sub capture {