File Coverage

blib/lib/Plack/Middleware/Deflater.pm

Criterion	Covered	Total	%
statement	98	110	89.0
branch	27	58	46.5
condition	8	25	32.0
subroutine	15	16	93.7
pod	2	2	100.0
total	150	211	71.0

package Plack::Middleware::Deflater;
use strict;
use 5.008001;
our $VERSION = '0.12';
use parent qw(Plack::Middleware);
use Plack::Util::Accessor qw( content_type vary_user_agent);
use Plack::Util;

sub prepare_app {
    my $self = shift;
    if ( my $match_cts = $self->content_type ) {
        $match_cts = [$match_cts] if ! ref $match_cts;
        $self->content_type($match_cts);
    }
}

sub call {
    my($self, $env) = @_;

    my $res = $self->app->($env);

    $self->response_cb($res, sub {
        my $res = shift;

        # can't operate on Content-Ranges
        return if $env->{HTTP_CONTENT_RANGE};

        return if $env->{"plack.skip-deflater"};

        my $h = Plack::Util::headers($res->[1]);
        my $content_type = $h->get('Content-Type') || '';
        $content_type =~ s/(;.*)$//;
        if ( my $match_cts = $self->content_type ) {
            my $match=0;
            for my $match_ct ( @{$match_cts} ) {
                if ( $content_type eq $match_ct ) {
                    $match++;
                    last;
                }
            }
            return unless $match;
        }

        if (Plack::Util::status_with_no_entity_body($res->[0]) or
            $h->exists('Cache-Control') && $h->get('Cache-Control') =~ /\bno-transform\b/) {
            return;
        }

        my @vary = split /\s*,\s*/, ($h->get('Vary') || '');
        push @vary, 'Accept-Encoding';
        push @vary, 'User-Agent' if $self->vary_user_agent;
        $h->set('Vary' => join(",", @vary));

        # some browsers might have problems, so set no-compress
        return if $env->{"psgix.no-compress"};

        # Some browsers might have problems with content types
        # other than text/html, so set compress-only-text/html
        if ( $env->{"psgix.compress-only-text/html"} ) {
            return if $content_type ne 'text/html';
        }

        # TODO check quality
        my $encoding = 'identity';
        if ( defined $env->{HTTP_ACCEPT_ENCODING} ) {
            for my $enc (qw(gzip deflate identity)) {
                if ( $env->{HTTP_ACCEPT_ENCODING} =~ /\b$enc\b/ ) {
                    $encoding = $enc;
                    last;
                }
            }
        }

        my $encoder;
        if ($encoding eq 'gzip' || $encoding eq 'deflate') {
            $encoder = Plack::Middleware::Deflater::Encoder->new($encoding);
        } elsif ($encoding ne 'identity') {
            my $msg = "An acceptable encoding for the requested resource is not found.";
            @$res = (406, ['Content-Type' => 'text/plain'], [ $msg ]);
            return;
        }

        if ($encoder) {
            $h->set('Content-Encoding' => $encoding);
            $h->remove('Content-Length');

            # normal response
            if ( $res->[2] && ref($res->[2]) && ref($res->[2]) eq 'ARRAY' ) {
                my $buf = '';
                foreach (@{$res->[2]}) {
                    $buf .= $encoder->print($_) if defined $_;
                }
                $buf .= $encoder->close();
                $res->[2] = [$buf];
                return;
            }

            # delayed or stream
            return sub {
                $encoder->print(shift);
            };
        }
    });
}

1;

package Plack::Middleware::Deflater::Encoder;

use strict;
use warnings;
use Compress::Zlib;

use constant GZIP_MAGIC => 0x1f8b;

sub new {
    my $class = shift;
    my $encoding = shift;
    my ($encoder,$status) = $encoding eq 'gzip'
        ? deflateInit(-WindowBits => -MAX_WBITS())
        : deflateInit(-WindowBits => MAX_WBITS());
    die 'Cannot create a deflation stream' if $status != Z_OK;

    bless {
        header => 0,
        closed => 0,
        encoding => $encoding,
        encoder => $encoder,
        crc => crc32(undef),
        length => 0,
    }, $class;
}

sub print : method {
    my $self = shift;
    return if $self->{closed};
    my $chunk = shift;
    if ( ! defined $chunk ) {
        my ($buf,$status) = $self->{encoder}->flush();
        die "deflate failed: $status" if ( $status != Z_OK );
        if ( !$self->{header} && $self->{encoding} eq 'gzip' ) {
            $buf = pack("nccVcc",GZIP_MAGIC,Z_DEFLATED,0,time(),0,$Compress::Raw::Zlib::gzip_os_code) . $buf
        }
        $buf .= pack("LL", $self->{crc},$self->{length}) if $self->{encoding} eq 'gzip';
        $self->{closed} = 1;
        return $buf;
    }

    my ($buf,$status) = $self->{encoder}->deflate($chunk);
    die "deflate failed: $status" if ( $status != Z_OK );
    $self->{length} += length $chunk;
    $self->{crc} = crc32($chunk,$self->{crc});
    if ( length $buf ) {
        if ( !$self->{header} && $self->{encoding} eq 'gzip' ) {
            $buf = pack("nccVcc",GZIP_MAGIC,Z_DEFLATED,0,time(),0,$Compress::Raw::Zlib::gzip_os_code) . $buf
        }
        $self->{header} = 1;
        return $buf;
    }
    return '';
}

sub close : method {
    $_[0]->print(undef);
}

sub closed {
    $_[0]->{closed};
}

1;


__END__