/usr/share/perl5/Plack/Loader/Shotgun.pm is in libplack-perl 0.9985-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 | package Plack::Loader::Shotgun;
use strict;
use parent qw(Plack::Loader);
use Storable;
use Try::Tiny;
use Plack::Middleware::BufferedStreaming;
sub preload_app {
my($self, $builder) = @_;
$self->{builder} = sub { Plack::Middleware::BufferedStreaming->wrap($builder->()) };
}
sub run {
my($self, $server) = @_;
my $app = sub {
my $env = shift;
pipe my $read, my $write;
my $pid = fork;
if ($pid) {
# parent
close $write;
my $res = Storable::thaw(join '', <$read>);
close $read;
waitpid($pid, 0);
return $res;
} else {
# child
close $read;
my $res;
try {
$env->{'psgi.streaming'} = 0;
$res = $self->{builder}->()->($env);
my @body;
Plack::Util::foreach($res->[2], sub { push @body, $_[0] });
$res->[2] = \@body;
} catch {
$env->{'psgi.errors'}->print($_);
$res = [ 500, [ "Content-Type", "text/plain" ], [ "Internal Server Error" ] ];
};
print {$write} Storable::freeze($res);
close $write;
exit;
}
};
$server->run($app);
}
1;
__END__
=head1 NAME
Plack::Loader::Shotgun - forking implementation of plackup
=head1 SYNOPSIS
plackup -L Shotgun
=head1 DESCRIPTION
Shotgun loader delays the compilation and execution of your
application until the runtime. When a new request comes in, this forks
a new child, compiles your code and runs the application.
This should be an ultimate alternative solution when reloading with
L<Plack::Middleware::Refresh> doesn't work, or plackup's default C<-r>
filesystem watcher causes problems. I can imagine this is useful for
applications which expects their application is only evaluated once
(like in-file templates) or on operating systems with broken fork
implementation, etc.
This is much like good old CGI's fork and run but you don't need a web
server, and there's a benefit of preloading modules that are not
likely to change. For instance if you develop a web application using
Moose and DBIx::Class,
plackup -MMoose -MDBIx::Class -L Shotgun yourapp.psgi
would preload those modules and only re-evaluates your code in every
request.
=head1 AUTHOR
Tatsuhiko Miyagawa with an inspiration from L<http://github.com/rtomayko/shotgun>
=head1 SEE ALSO
L<plackup>
=cut
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