gistfile1.pl

package Plack::Middleware::AsyncSupport;
use strict;
use warnings;
use base qw/Plack::Middleware/;

our $USE_CORO = 1;

use Coro;
use Coro::Channel;
use IO::Handle::Util qw(io_from_getline);

sub call {
    my $self = shift;
    my $env  = shift;

    my $res = $self->app->($env);
    my $body = $res->[2];

    if (ref $body eq "CODE" && $USE_CORO) {
        my $queue = Coro::Channel->new;
        async {
            my $closed = 0;
            my $cancel = $body->(
                sub { warn "write"; $queue->put($_[0]) }, # write cb
                sub { warn "close"; $closed = 1; $queue->shutdown;  }, # close cb
            );
            if (!$closed) {
                # TODO: event based code, wait close cb, check timeout
            }
        };
        $res->[2] = io_from_getline sub { $queue->get };
    } elsif (ref $body eq "CODE") {
        # TODO
        # $res->[2] = Plack::AsyncResponse->new($env, $body);
    }
    
    return $res;
}

1;

__END__

=head1 NAME

Plack::Middleware::AsyncSupport - convert coderef to Stream

=head1 SYNOPSIS

  use Plack::Builder;
  use Plack::Middleware qw(AsyncSupport);

  # your app with coro
  # blocking code, run in thread(Coro) or fork
  use Coro::Timer qw(sleep);
  my $app = sub {
      my $body = sub {
         my ($writer, $close) = @_;
         my $i = 0;
         while ($i < 10) {
             $writer->(time . "\n");
             sleep 1;
             $i++;
         }
         $close->();
     };
     return [200, [], $body]; 
  };

  # TODO: your app with AnyEvent
  # non-blocking code, return canceler
  my $app = sub {
      my $body = sub {
         my ($writer, $close) = @_;
         my $i = 0;
         my $timer; $timer = AE::timer 0, 1, sub {
            $writer->(time . "\n");
            $i++;
            if ($i >= 10) { 
                $close->();
                undef $timer;
            }
         };
         return sub { undef $timer } # canceler & keep $timer
     };
     return [200, [], $body]; 
  };
  
  builder {
      enable Plack::Middleware::OtherMiddleware;

      enable Plack::Middleware::AsyncSupport;
      $app;
  };

=head1 DESCRIPTION

=head1 AUTHOR

mala

=head1 SEE ALSO

L<Plack::Middleware> L<Plack::Builder>

=cut