Using Confirms (publisher acknowledgements) with php-amqplib - php

Question

I'm trying to figure out how to use Confirms (Publisher Acknowledgements) using the php-amqplib library, which is the library recommended for using RabbitMQ with PHP at http://rabbitmq.com/.
The code itself isn't very well documented and I can't find anything that mirrors the interfaces of the Java and python interfaces that I've found.
The Java example is here.
I've grepped for the various combinations of function names that I could think of in the PHP source and haven't found anything. I'm looking for something similar to:
$channel->confirm_select();
...
$channel->wait();
It looks like https://github.com/videlalvaro/php-amqplib/blob/master/PhpAmqpLib/Helper/Protocol/Protocol091.php has support for the functionality, but I don't see how it is exposed to the user.

Answer 1

I was looking for this today and found that php-amqplib has implemented it.
Check out this demo for details.
Here's a snippet:
$connection = new AMQPStreamConnection(HOST, PORT, USER, PASS, VHOST);
$channel = $connection->channel();
$channel->set_ack_handler(
function (AMQPMessage $message) {
echo "Message acked with content " . $message->body . PHP_EOL;
}
);
$channel->set_nack_handler(
function (AMQPMessage $message) {
echo "Message nacked with content " . $message->body . PHP_EOL;
}
);
/*
* bring the channel into publish confirm mode.
* if you would call $ch->tx_select() befor or after you brought the channel into this mode
* the next call to $ch->wait() would result in an exception as the publish confirm mode and transactions
* are mutually exclusive
*/
$channel->confirm_select();
/*
name: $exchange
type: fanout
passive: false // don't check if an exchange with the same name exists
durable: false // the exchange won't survive server restarts
auto_delete: true //the exchange will be deleted once the channel is closed.
*/
$channel->exchange_declare($exchange, 'fanout', false, false, true);
$i = 1;
$msg = new AMQPMessage($i, array('content_type' => 'text/plain'));
$channel->basic_publish($msg, $exchange);
/*
* watching the amqp debug output you can see that the server will ack the message with delivery tag 1 and the
* multiple flag probably set to false
*/
$channel->wait_for_pending_acks();

Answer 2

Apparently neither the PECL AMQP library nor the pure php-amqplib library implement the Confirms extension. The only real solution at this point is to implement two queues to simulate acknowledgements to the publisher.
There are plans to implement Confirms in both libraries, but I don't see any movement in either.