package Tak::Loop;
+use IO::Select;
use Moo;
+has is_running => (is => 'rw', clearer => 'loop_stop');
+
+has _read_watches => (is => 'ro', default => sub { {} });
+has _read_select => (is => 'ro', default => sub { IO::Select->new });
+
+sub pass_watches_to {
+ my ($self, $new_loop) = @_;
+ foreach my $fh ($self->_read_select->handles) {
+ $new_loop->watch_io(
+ handle => $fh,
+ on_read_ready => $self->_read_watches->{$fh}
+ );
+ }
+}
+
+sub watch_io {
+ my ($self, %watch) = @_;
+ my $fh = $watch{handle};
+ if (my $cb = $watch{on_read_ready}) {
+ $self->_read_select->add($fh);
+ $self->_read_watches->{$fh} = $cb;
+ }
+}
+
+sub unwatch_io {
+ my ($self, %watch) = @_;
+ my $fh = $watch{handle};
+ if ($watch{on_read_ready}) {
+ $self->_read_select->remove($fh);
+ delete $self->_read_watches->{$fh};
+ }
+}
+
+sub loop_once {
+ my ($self) = @_;
+ my $read = $self->_read_watches;
+ my ($readable) = IO::Select->select($self->_read_select, undef, undef, 0.5);
+ # I would love to trap errors in the select call but IO::Select doesn't
+ # differentiate between an error and a timeout.
+ # -- no, love, mst.
+ foreach my $fh (@$readable) {
+ $read->{$fh}();
+ }
+}
+
+sub loop_forever {
+ my ($self) = @_;
+ $self->is_running(1);
+ while ($self->is_running) {
+ $self->loop_once;
+ }
+}
+
1;