mboxgz: use Compress::Raw::Zlib instead of IO::Compress::Gzip

IO::Compress::Gzip is a wrapper around Compress::Raw::Zlib,
anyways, and being able to easily detach buffers to return them
via ->getline is nice.  This results in a 1-2% performance
improvement when fetching giant mboxes.

1 files changed, 24 insertions, 17 deletions

diff --git a/lib/PublicInbox/MboxGz.pm b/lib/PublicInbox/MboxGz.pm
index 2919ad6a..2a55447f 100644
--- a/lib/PublicInbox/MboxGz.pm
+++ b/lib/PublicInbox/MboxGz.pm
@@ -7,17 +7,15 @@ use Email::Simple;
 use PublicInbox::Hval qw/to_filename/;
 use PublicInbox::Mbox;
 use IO::Compress::Gzip;
+use Compress::Raw::Zlib qw(Z_FINISH Z_OK);
+my %OPT = (-WindowBits => 15 + 16, -AppendOutput => 1);
 
 sub new {
         my ($class, $ctx, $cb) = @_;
-        my $buf = '';
         $ctx->{base_url} = $ctx->{-inbox}->base_url($ctx->{env});
-        bless {
-                buf => \$buf,
-                gz => IO::Compress::Gzip->new(\$buf, Time => 0),
-                cb => $cb,
-                ctx => $ctx,
-        }, $class;
+        my ($gz, $err) = Compress::Raw::Zlib::Deflate->new(%OPT);
+        $err == Z_OK or die "Deflate->new failed: $err";
+        bless { gz => $gz, cb => $cb, ctx => $ctx }, $class;
 }
 
 sub response {
@@ -32,31 +30,40 @@ sub response {
         [ 200, \@h, $body ];
 }
 
+sub gzip_fail ($$) {
+        my ($ctx, $err) = @_;
+        $ctx->{env}->{'psgi.errors'}->print("deflate failed: $err\n");
+        '';
+}
+
 # called by Plack::Util::foreach or similar
 sub getline {
         my ($self) = @_;
         my $ctx = $self->{ctx} or return;
         my $gz = $self->{gz};
+        my $buf = delete($self->{buf});
         while (my $smsg = $self->{cb}->()) {
                 my $mref = $ctx->{-inbox}->msg_by_smsg($smsg) or next;
                 my $h = Email::Simple->new($mref)->header_obj;
-                $gz->write(PublicInbox::Mbox::msg_hdr($ctx, $h, $smsg->{mid}));
-                $gz->write(PublicInbox::Mbox::msg_body($$mref));
 
-                my $bref = $self->{buf};
-                if (length($$bref) >= 8192) {
-                        my $ret = $$bref; # copy :<
-                        ${$self->{buf}} = '';
-                        return $ret;
-                }
+                my $err = $gz->deflate(
+                        PublicInbox::Mbox::msg_hdr($ctx, $h, $smsg->{mid}),
+                        $buf);
+                return gzip_fail($ctx, $err) if $err != Z_OK;
+
+                $err = $gz->deflate(PublicInbox::Mbox::msg_body($$mref), $buf);
+                return gzip_fail($ctx, $err) if $err != Z_OK;
+
+                return $buf if length($buf) >= 8192;
 
                 # be fair to other clients on public-inbox-httpd:
+                $self->{buf} = $buf;
                 return '';
         }
-        delete($self->{gz})->close;
         # signal that we're done and can return undef next call:
         delete $self->{ctx};
-        ${delete $self->{buf}};
+        my $err = $gz->flush($buf, Z_FINISH);
+        $err == Z_OK ? $buf : gzip_fail($ctx, $err);
 }
 
 sub close {} # noop