zakame/app.pl

## app.pl
#!/usr/bin/env perl
use Mojolicious::Lite;

package Model::FileWatch {
  use Mojo::Base 'Mojo::EventEmitter';
  use Mojo::Promise;
  use IO::File;

  has 'file';

  sub watch {
    my $self = shift;
    my $p    = Mojo::Promise->new;
    my $fh   = IO::File->new;
    unless ($fh->open($self->file, 'r')) {
      return $p->reject("watching @{[$self->file]} failed: $!");
    }

    $fh->seek(0, 2);
    my $id = $p->ioloop->recurring(
      0.25 => sub {
        $fh->seek(0, 1);
        if (my $line = $fh->getline) {
          $self->emit(oneline => $line);
        }
      }
    );

    $self->once(finish => sub { $p->ioloop->remove($id) });

    $p;
  }
}

websocket '/tail' => sub {
  my $c = shift;
  my $m = Model::FileWatch->new(file => '/var/log/messages');

  $c->inactivity_timeout(300);

  $m->on(
    oneline => sub {
      my ($tail, $line) = @_;
      $c->send($line);
    }
  );

  $c->on(finish => sub { $m->emit('finish')->unsubscribe('oneline') });

  $m->watch->catch(sub { $c->send(@_) })->wait;
};

get '/' => 'index';

app->start;

__DATA__
@@ index.html.ep
<!DOCTYPE html>
<html>
  <head><title>Tail</title></head>
  <body>
    <script>
      var ws = new WebSocket('<%= url_for('tail')->to_abs %>');

      // Incoming messages
      ws.onmessage = function (event) {
        document.body.innerHTML += event.data + '<br/>';
        window.scrollTo(0, document.body.scrollHeight);
      };

      // Ping from client side to keep WS connection alive
      window.setInterval(function () { ws.send('') }, 10000);
    </script>
  </body>
</html>

__END__
	#!/usr/bin/env perl
	use Mojolicious::Lite;

	package Model::FileWatch {
	use Mojo::Base 'Mojo::EventEmitter';
	use Mojo::Promise;
	use IO::File;

	has 'file';

	sub watch {
	my $self = shift;
	my $p = Mojo::Promise->new;
	my $fh = IO::File->new;
	unless ($fh->open($self->file, 'r')) {
	return $p->reject("watching @{[$self->file]} failed: $!");
	}

	$fh->seek(0, 2);
	my $id = $p->ioloop->recurring(
	0.25 => sub {
	$fh->seek(0, 1);
	if (my $line = $fh->getline) {
	$self->emit(oneline => $line);
	}
	}
	);

	$self->once(finish => sub { $p->ioloop->remove($id) });

	$p;
	}
	}

	websocket '/tail' => sub {
	my $c = shift;
	my $m = Model::FileWatch->new(file => '/var/log/messages');

	$c->inactivity_timeout(300);

	$m->on(
	oneline => sub {
	my ($tail, $line) = @_;
	$c->send($line);
	}
	);

	$c->on(finish => sub { $m->emit('finish')->unsubscribe('oneline') });

	$m->watch->catch(sub { $c->send(@_) })->wait;
	};

	get '/' => 'index';

	app->start;

	__DATA__
	@@ index.html.ep
	<!DOCTYPE html>
	<html>
	<head><title>Tail</title></head>
	<body>
	<script>
	var ws = new WebSocket('<%= url_for('tail')->to_abs %>');

	// Incoming messages
	ws.onmessage = function (event) {
	document.body.innerHTML += event.data + '<br/>';
	window.scrollTo(0, document.body.scrollHeight);
	};

	// Ping from client side to keep WS connection alive
	window.setInterval(function () { ws.send('') }, 10000);
	</script>
	</body>
	</html>

	__END__