IPC::PubSub 0.22

IPC::PubSub is Perl module for Interprocess Publish/Subscribe channels.

SYNOPSIS

# A new message bus with the DBM::Deep backend
# (Other possible backends include Memcached and PlainHash)
my $bus = IPC::PubSub->new(DBM_Deep => /tmp/pubsub.db);

# A channel is any arbitrary string
my $channel = #perl6;

# Register a new publisher (you can publish to multiple channels)
my $pub = $bus->new_publisher("#perl6", "#moose");

# Publish a message (may be a complex object) to those channels
$pub->msg("This is a message");

# Register a new subscriber (you can subscribe to multiple channels)
my $sub = $bus->new_subscriber("#moose");

# Publish an object to channels
$pub->msg("This is another message");

# Set all subsequent messages from this publisher to expire in 30 seconds
$pub->expiry(30);
$pub->msg("This message will go away in 30 seconds");

# Simple get: Returns the messages sent since the previous get,
# but only for the first channel.
my @msgs = $sub->get;

# Simple get, with an explicit channel key (must be among the ones
# it initially subscribed to)
my @moose_msgs = $sub->get("#moose");

# Complex get: Returns a hash reference from channels to array
# references of [timestamp, message].
my $hash_ref = $sub->get_all;

# Changing the list of channels we subscribe to
$sub->subscribe(some-other-channel);
$sub->unsubscribe(some-other-channel);

# Changing the list of channels we publish to
$pub->publish(some-other-channel);
$pub->unpublish(some-other-channel);

# Listing and checking if we are in a channel
my @sub_channels = $sub->channels;
my @pub_channels = $pub->channels;
print "Sub is in #moose" if $sub->channels->{#moose};
print "Pub is in #moose" if $pub->channels->{#moose};

# Raw cache manipulation APIs (not advised; use ->modify instead)
$bus->lock(channel);
$bus->unlock(channel);
my @timed_msgs = $bus->fetch(key1, key2, key3);
$bus->store(key, value, time, 30);

# Atomic updating of cache content; $_ is stored back on the
# end of the callback.
my $rv = $bus->modify(key => sub { delete $_->{foo} });

# Shorthand for $bus->modify(key => sub { $_ = val });
$bus->modify(key => val);

# Shorthand for $bus->modify(key => sub { $_ });
$bus->modify(key);

This module provides a simple API for publishing messages to channels and for subscribing to them.

When a message is published on a channel, all subscribers currently in that channel will get it on their next get or get_all call.

Currently, it offers three backends: DBM_Deep for on-disk storage, Memcached for possibly multi-host storage, and PlainHash for single-process storage.

Please see the tests in t/ for this distribution, as well as "SYNOPSIS" above, for some usage examples; detailed documentation is not yet available.