wwwlisting: use GzipFilter for HTML

The changes to GzipFilter here may be beneficial for building
HTML and XML responses in other places, too.

1 files changed, 26 insertions, 2 deletions

diff --git a/lib/PublicInbox/GzipFilter.pm b/lib/PublicInbox/GzipFilter.pm
index 95fced05..8cc5ea00 100644
--- a/lib/PublicInbox/GzipFilter.pm
+++ b/lib/PublicInbox/GzipFilter.pm
@@ -42,7 +42,7 @@ sub gzf_maybe ($$) {
 # for GetlineBody (via Qspawn) when NOT using $env->{'pi-httpd.async'}
 # Also used for ->getline callbacks
 sub translate ($$) {
-        my $self = $_[0];
+        my $self = $_[0]; # $_[1] => input
 
         # allocate the zlib context lazily here, instead of in ->new.
         # Deflate contexts are memory-intensive and this object may
@@ -72,10 +72,34 @@ sub write {
         $_[0]->{fh}->write(translate($_[0], $_[1]));
 }
 
+# similar to ->translate; use this when we're sure we know we have
+# more data to buffer after this
+sub zmore {
+        my $self = $_[0]; # $_[1] => input
+        my $err = $self->{gz}->deflate($_[1], $self->{zbuf});
+        die "gzip->deflate: $err" if $err != Z_OK;
+        '';
+}
+
+# flushes and returns the final bit of gzipped data
+sub zflush ($;$) {
+        my $self = $_[0]; # $_[1] => final input (optional)
+        my $zbuf = delete $self->{zbuf};
+        my $gz = delete $self->{gz};
+        my $err;
+        if (defined $_[1]) {
+                $err = $gz->deflate($_[1], $zbuf);
+                die "gzip->deflate: $err" if $err != Z_OK;
+        }
+        $err = $gz->flush($zbuf, Z_FINISH);
+        die "gzip->flush: $err" if $err != Z_OK;
+        $zbuf;
+}
+
 sub close {
         my ($self) = @_;
         my $fh = delete $self->{fh};
-        $fh->write(translate($self, undef));
+        $fh->write(zflush($self));
         $fh->close;
 }