www*stream: gzip ->getline responses

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

diff --git a/lib/PublicInbox/GzipFilter.pm b/lib/PublicInbox/GzipFilter.pm
index 864095862096f423ed0d02e2214087515b60673c..95fced053579cebfc34359138d3077a2afa19847 100644 (file)
--- a/lib/PublicInbox/GzipFilter.pm
+++ b/lib/PublicInbox/GzipFilter.pm
@@ -4,9 +4,11 @@
 # Qspawn filter
 package PublicInbox::GzipFilter;
 use strict;
-use bytes (); # length
+use parent qw(Exporter);
 use Compress::Raw::Zlib qw(Z_FINISH Z_OK);
+our @EXPORT_OK = qw(gzip_maybe gzf_maybe);
 my %OPT = (-WindowBits => 15 + 16, -AppendOutput => 1);
+my @GZIP_HDRS = qw(Vary Accept-Encoding Content-Encoding gzip);
 
 sub new { bless {}, shift }
 
@@ -17,28 +19,49 @@ sub attach {
        $self
 }
 
+sub gzip_maybe ($$) {
+       my ($res_hdr, $env) = @_;
+       return if (($env->{HTTP_ACCEPT_ENCODING}) // '') !~ /\bgzip\b/;
+
+       my ($gz, $err) = Compress::Raw::Zlib::Deflate->new(%OPT);
+       return if $err != Z_OK;
+
+       # in case Plack::Middleware::Deflater is loaded:
+       $env->{'plack.skip-deflater'} = 1;
+
+       push @$res_hdr, @GZIP_HDRS;
+       $gz;
+}
+
+sub gzf_maybe ($$) {
+       my ($res_hdr, $env) = @_;
+       my $gz = gzip_maybe($res_hdr, $env) or return 0;
+       bless { gz => $gz }, __PACKAGE__;
+}
+
 # for GetlineBody (via Qspawn) when NOT using $env->{'pi-httpd.async'}
+# Also used for ->getline callbacks
 sub translate ($$) {
        my $self = $_[0];
 
        # allocate the zlib context lazily here, instead of in ->new.
        # Deflate contexts are memory-intensive and this object may
        # be sitting in the Qspawn limiter queue for a while.
-       my $gz = $self->{gz} ||= do {
+       my $gz = $self->{gz} //= do {
                my ($g, $err) = Compress::Raw::Zlib::Deflate->new(%OPT);
                $err == Z_OK or die "Deflate->new failed: $err";
                $g;
        };
        my $zbuf = delete($self->{zbuf});
        if (defined $_[1]) { # my $buf = $_[1];
-               my $err = $self->{gz}->deflate($_[1], $zbuf);
+               my $err = $gz->deflate($_[1], $zbuf);
                die "gzip->deflate: $err" if $err != Z_OK;
                return $zbuf if length($zbuf) >= 8192;
 
                $self->{zbuf} = $zbuf;
                '';
        } else { # undef == EOF
-               my $err = $self->{gz}->flush($zbuf, Z_FINISH);
+               my $err = $gz->flush($zbuf, Z_FINISH);
                die "gzip->flush: $err" if $err != Z_OK;
                $zbuf;
        }