NAME
Mojo::Pg::PubSub - Publish/Subscribe
SYNOPSIS
use Mojo::Pg::PubSub;
my $pubsub = Mojo::Pg::PubSub->new(pg => $pg);
my $cb = $pubsub->listen(foo => sub {
my ($pubsub, $payload) = @_;
say "Received: $payload";
});
$pubsub->notify(foo => 'bar');
$pubsub->unlisten(foo => $cb);DESCRIPTION
Mojo::Pg::PubSub is a scalable implementation of the publish/subscribe pattern used by Mojo::Pg. It is based on PostgreSQL notifications and allows many consumers to share the same database connection, to avoid many common scalability problems.
Note that this module is EXPERIMENTAL and might change without warning!
EVENTS
Mojo::Pg::PubSub inherits all events from Mojo::EventEmitter and can emit the following new ones.
reconnect
$pubsub->on(reconnect => sub {
my ($pubsub, $db) = @_;
...
});Emitted after switching to a new database connection for sending and receiving notifications.
ATTRIBUTES
Mojo::Pg::PubSub implements the following attributes.
pg
my $pg = $pubsub->pg;
$pubsub = $pubsub->pg(Mojo::Pg->new);Mojo::Pg object this publish/subscribe container belongs to.
METHODS
Mojo::Pg::PubSub inherits all methods from Mojo::EventEmitter and implements the following new ones.
listen
my $cb = $pubsub->listen(foo => sub {...});Subscribe to a channel, there is no limit on how many subscribers a channel can have.
# Subscribe to the same channel twice
$pubsub->listen(foo => sub {
my ($pubsub, $payload) = @_;
say "One: $payload";
});
$pubsub->listen(foo => sub {
my ($pubsub, $payload) = @_;
say "Two: $payload";
});notify
$pubsub = $pubsub->notify(foo => 'bar');Notify a channel.
unlisten
$pubsub = $pubsub->unlisten(foo => $cb);Unsubscribe from a channel.