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NAME

Net::Async::AMQP::Channel - represents a single channel in an MQ connection

VERSION

version 0.013

SYNOPSIS

 use IO::Async::Loop;
 use Net::Async::AMQP;
 my $loop = IO::Async::Loop->new;
 $loop->add(my $amqp = Net::Async::AMQP->new);
 $amqp->connect(
   host => 'localhost',
   username => 'guest',
   password => 'guest',
 )->then(sub {
  shift->open_channel->publish(
   type => 'application/json'
  )
 });

DESCRIPTION

Each Net::Async::AMQP::Channel instance represents a virtual channel for communicating with the MQ server.

Channels are layered over the TCP protocol and most of the common AMQP frames operate at channel level - typically you'd connect to the server, open one channel for one-shot requests such as binding/declaring/publishing, and a further channel for every consumer.

Since any error typically results in a closed channel, it's not recommended to have multiple consumers on the same channel if there's any chance the Basic.Consume request will fail.

METHODS

confirm_mode

Switches confirmation mode on for this channel. In confirm mode, all messages must be ACKed explicitly after delivery.

Note that this is an irreversible operation - once confirm mode has been enabled on a channel, closing that channel and reopening is the only way to turn off confirm mode again.

Returns a Future which will resolve with this channel once complete.

 $ch->confirm_mode ==> $ch

exchange_declare

Declares a new exchange.

Returns a Future which will resolve with this channel once complete.

 $ch->exchange_declare(
  exchange   => 'some_exchange',
  type       => 'fanout',
  autodelete => 1,
 ) ==> $ch

queue_declare

Returns a Future which will resolve with the new Net::Async::AMQP::Queue instance once complete.

 $ch->queue_declare(
  queue      => 'some_queue',
 ) ==> $q

publish

Publishes a message on this channel.

Returns a Future which will resolve with the channel instance once the server has confirmed publishing is complete.

 $ch->publish(
  exchange => 'some_exchange',
  routing_key => 'some.rkey.here',
  type => 'some_type',
 ) ==> $ch

qos

Changes QOS settings on the channel. Probably most useful for limiting the number of messages that can be delivered to us before we have to ACK/NAK to proceed.

Returns a Future which will resolve with the channel instance once the operation is complete.

 $ch->qos(
  prefetch_count => 5,
  prefetch_size  => 1048576,
 ) ==> $ch

ack

Acknowledge a specific delivery.

Returns a Future which will resolve with the channel instance once the operation is complete.

 $ch->ack(
  delivery_tag => 123,
 ) ==> $ch

Example output:

                'method_id' => 40,
                'reply_code' => 404,
                'class_id' => 60,
                'reply_text' => 'NOT_FOUND - no exchange \'invalidchan\' in vhost \'vhost\''

on_close

Called when the channel has been closed.

send_frame

Proxy frame sending requests to the parent Net::Async::AMQP instance.

close

Ask the server to close this channel.

Returns a Future which will resolve with the channel instance once the operation is complete.

 $ch->close(
  code => 404,
  text => 'something went wrong',
 ) ==> $ch

push_pending

remove_pending

Removes a coderef from the pending event handler.

Returns $self .

next_pending

Retrieves the next pending handler for the given incoming frame type (see "amqp_frame_type" in Net::Async::AMQP::Utils), and calls it.

Takes the following parameters:

  • $frame - the frame itself

Returns $self.

METHODS - Accessors

amqp

The parent Net::Async::AMQP instance.

bus

Event bus. Used for sharing channel-specific events.

write

Proxy a write operation through the parent Net::Async::AMQP instance.

future

The underlying Future for this channel which will resolve to the instance once the channel is open.

id

This channel ID.

INHERITED METHODS

IO::Async::Notifier

add_child, adopt_future, can_event, children, configure_unknown, debug_printf, get_loop, invoke_error, invoke_event, loop, make_event_cb, maybe_invoke_event, maybe_make_event_cb, new, notifier_name, parent, remove_child, remove_from_parent

AUTHOR

Tom Molesworth <cpan@perlsite.co.uk>

LICENSE

Licensed under the same terms as Perl itself, with additional licensing terms for the MQ spec to be found in share/amqp0-9-1.extended.xml ('a worldwide, perpetual, royalty-free, nontransferable, nonexclusive license to (i) copy, display, distribute and implement the Advanced Messaging Queue Protocol ("AMQP") Specification').