add level option

README.md

@@ -26,6 +26,18 @@ builder {
 This middleware encodes the body of the response using Zstandard, based on the `Accept-Encoding`
 request header.
 
+# CONFIGURATION
+
+- level
+
+    Compression level.  Should be an integer from 1 to 22.  If not provided, then the default will
+    be chosen by [Compress::Stream::Zstd](https://metacpan.org/pod/Compress::Stream::Zstd).
+
+# SEE ALSO
+
+- [Plack::Middleware::Deflater](https://metacpan.org/pod/Plack::Middleware::Deflater)
+- [Compress::Stream::Zstd](https://metacpan.org/pod/Compress::Stream::Zstd)
+
 # AUTHOR
 
 Graham Ollis <[email protected]>

lib/Plack/Middleware/Zstandard.pm

@@ -8,10 +8,16 @@ package Plack::Middleware::Zstandard {
 
   use parent qw( Plack::Middleware );
   use Plack::Util ();
+  use Plack::Util::Accessor qw( level _constructor_args );
   use Ref::Util qw( is_plain_arrayref );
   use Compress::Stream::Zstd::Compressor ();
 
   sub prepare_app ($self) {
+    if(defined $self->level) {
+      $self->_constructor_args([$self->level]);
+    } else {
+      $self->_constructor_args([]);
+    }
   }
 
   sub call ($self, $env) {
@@ -37,7 +43,7 @@ package Plack::Middleware::Zstandard {
       $h->set('Content-Encoding' => 'zstd');
       $h->remove('Content-Length');
 
-      my $compressor = Compress::Stream::Zstd::Compressor->new;
+      my $compressor = Compress::Stream::Zstd::Compressor->new($self->_constructor_args->@*);
 
       if($res->[2] && is_plain_arrayref $res->[2]) {
         $res->[2] = [grep length, map { $compressor->compress($_) } grep defined, $res->[2]->@*];
@@ -73,4 +79,25 @@ package Plack::Middleware::Zstandard {
 This middleware encodes the body of the response using Zstandard, based on the C<Accept-Encoding>
 request header.
 
+=head1 CONFIGURATION
+
+=over 4
+
+=item level
+
+Compression level.  Should be an integer from 1 to 22.  If not provided, then the default will
+be chosen by L<Compress::Stream::Zstd>.
+
+=back
+
+=head1 SEE ALSO
+
+=over 4
+
+=item L<Plack::Middleware::Deflater>
+
+=item L<Compress::Stream::Zstd>
+
+=back
+
 =cut

t/00_diag.t

@@ -17,6 +17,7 @@ $modules{$_} = $_ for qw(
   Plack::Builder
   Plack::Middleware
   Plack::Util
+  Plack::Util::Accessor
   Ref::Util
   Test2::Tools::HTTP
   Test2::V0

t/plack_middleware_zstandard.t

@@ -1,4 +1,5 @@
 use Test2::V0 -no_srand => 1;
+use experimental qw( signatures );
 use Plack::Builder;
 use Test2::Tools::HTTP qw( :short psgi_app_guard );
 use HTTP::Request::Common;
@@ -187,6 +188,81 @@ subtest 'basic' => sub {
 
 };
 
+subtest 'level' => sub {
+
+  my @last_new_args;
+  my $mock = mock 'Compress::Stream::Zstd::Compressor' => (
+    before => [
+      new => sub ($class, @args) {
+        @last_new_args = @args;
+      },
+    ],
+  );
+
+  subtest 'override level = 22' => sub {
+
+    my $app = psgi_app_guard builder {
+      enable 'Zstandard', level => 22;
+      sub { return [ 200, ['Content-Type' => 'text/plain'], ['Hello World']] };
+    };
+
+    req(
+      GET('/', 'Accept-Encoding' => 'zstd'),
+      res {
+        code 200;
+        content_type 'text/plain';
+        header 'Content-Length' => DNE();
+        header 'Content-Encoding' => 'zstd';
+        header 'Vary', 'Accept-Encoding';
+      },
+    );
+
+    is(
+      decompress(),
+      'Hello World',
+      'content',
+    );
+
+    is(
+      \@last_new_args,
+      [22],
+      'expected args',
+    );
+  };
+
+  subtest 'default' => sub {
+
+    my $app = psgi_app_guard builder {
+      enable 'Zstandard';
+      sub { return [ 200, ['Content-Type' => 'text/plain'], ['Hello World']] };
+    };
+
+    req(
+      GET('/', 'Accept-Encoding' => 'zstd'),
+      res {
+        code 200;
+        content_type 'text/plain';
+        header 'Content-Length' => DNE();
+        header 'Content-Encoding' => 'zstd';
+        header 'Vary', 'Accept-Encoding';
+      },
+    );
+
+    is(
+      decompress(),
+      'Hello World',
+      'content',
+    );
+
+    is(
+      \@last_new_args,
+      [],
+      'expected args',
+    );
+  };
+
+};
+
 sub note_debug {
   note $_ for map { $_->as_string} (tx->req, tx->res);
 }