—package
Mojo::IOLoop::Delay;
use
Mojo::IOLoop;
has
ioloop
=>
sub
{ Mojo::IOLoop->singleton };
sub
begin {
my
$self
=
shift
;
my
$id
=
$self
->{counter}++;
return
sub
{
shift
;
$self
->_step(
$id
,
@_
) };
}
sub
end {
shift
->_step(
undef
,
@_
) }
sub
steps {
my
$self
=
shift
;
$self
->{steps} = [
@_
];
$self
->begin->();
return
$self
;
}
sub
wait
{
my
$self
=
shift
;
my
@args
;
$self
->once(
finish
=>
sub
{
shift
->ioloop->stop;
@args
=
@_
});
$self
->ioloop->start;
return
wantarray
?
@args
:
$args
[0];
}
sub
_step {
my
(
$self
,
$id
) = (
shift
,
shift
);
# Arguments
my
$ordered
=
$self
->{ordered} ||= [];
my
$unordered
=
$self
->{unordered} ||= [];
if
(
defined
$id
) {
$ordered
->[
$id
] = [
@_
] }
else
{
push
@$unordered
,
@_
}
# Wait for more events
return
$self
->{counter}
if
--
$self
->{counter};
# Next step
my
$cb
=
shift
@{
$self
->{steps} ||= []};
$self
->{
$_
} = []
for
qw(ordered unordered)
;
my
@args
= ((
map
{
@$_
}
grep
{
defined
}
@$ordered
),
@$unordered
);
$self
->
$cb
(
@args
)
if
$cb
;
# Finished
$self
->emit(
'finish'
,
@args
)
if
!
$self
->{counter} && !@{
$self
->{steps}} && !
$self
->{finished}++;
return
0;
}
1;
=head1 NAME
Mojo::IOLoop::Delay - Control the flow of events
=head1 SYNOPSIS
use Mojo::IOLoop::Delay;
# Synchronize multiple events
my $delay = Mojo::IOLoop::Delay->new;
$delay->on(finish => sub { say 'BOOM!' });
for my $i (1 .. 10) {
$delay->begin;
Mojo::IOLoop->timer($i => sub {
say 10 - $i;
$delay->end;
});
}
# Sequentialize multiple events
my $delay = Mojo::IOLoop::Delay->new;
$delay->steps(
# First step (simple timer)
sub {
my $delay = shift;
Mojo::IOLoop->timer(2 => $delay->begin);
say 'Second step in 2 seconds.';
},
# Second step (parallel timers)
sub {
my ($delay, @args) = @_;
Mojo::IOLoop->timer(1 => $delay->begin);
Mojo::IOLoop->timer(3 => $delay->begin);
say 'Third step in 3 seconds.';
},
# Third step (the end)
sub {
my ($delay, @args) = @_;
say 'And done after 5 seconds total.';
}
);
# Wait for events if necessary
$delay->wait unless Mojo::IOLoop->is_running;
=head1 DESCRIPTION
L<Mojo::IOLoop::Delay> controls the flow of events for L<Mojo::IOLoop>.
=head1 EVENTS
L<Mojo::IOLoop::Delay> inherits all events from L<Mojo::EventEmitter> and can
emit the following new ones.
=head2 finish
$delay->on(finish => sub {
my ($delay, @args) = @_;
...
});
Emitted once the active event counter reaches zero and there are no more
steps.
=head1 ATTRIBUTES
L<Mojo::IOLoop::Delay> implements the following attributes.
=head2 ioloop
my $ioloop = $delay->ioloop;
$delay = $delay->ioloop(Mojo::IOLoop->new);
Event loop object to control, defaults to the global L<Mojo::IOLoop>
singleton.
=head1 METHODS
L<Mojo::IOLoop::Delay> inherits all methods from L<Mojo::EventEmitter> and
implements the following new ones.
=head2 begin
my $cb = $delay->begin;
Increment active event counter, the returned callback can be used instead of
C<end>, which has the advantage of preserving the order of arguments. Note
that the first argument passed to the callback will be ignored.
my $delay = Mojo::IOLoop->delay;
Mojo::UserAgent->new->get('mojolicio.us' => $delay->begin);
my $tx = $delay->wait;
=head2 end
my $remaining = $delay->end;
my $remaining = $delay->end(@args);
Decrement active event counter, all arguments are queued for the next step or
C<finish> event and C<wait> method.
=head2 steps
$delay = $delay->steps(sub {...}, sub {...});
Sequentialize multiple events, the first callback will run right away, and the
next one once the active event counter reaches zero, this chain will continue
until there are no more callbacks left.
=head2 wait
my @args = $delay->wait;
Start C<ioloop> and stop it again once the C<finish> event gets emitted, only
works when C<ioloop> is not running already.
# Use the "finish" event to synchronize portably
$delay->on(finish => sub {
my ($delay, @args) = @_;
...
});
$delay->wait unless $delay->ioloop->is_running;
=head1 SEE ALSO
L<Mojolicious>, L<Mojolicious::Guides>, L<http://mojolicio.us>.
=cut