Swarrot is PHP library to consume messages from a broker.

The recommended way to install Swarrot is through Composer. Require the swarrot/swarrot package into your composer.json file:

{
    "require": {
        "swarrot/swarrot": "@stable"
    }
}

Protip: you should browse the swarrot/swarrot page to choose a stable version to use, avoid the @stable meta constraint.

First, you need to create a message provider to retrieve message from your broker. For example, with A PeclPackageMessageProvider (retrieve message from an AMQP broker with the pecl amqp package:

use Swarrot\Broker\PeclPackageMessageProvider;

// Create connection
$connection = new \AMQPConnection();
$connection->connect();
$channel = new \AMQPChannel($connection);
// Get the queue to consume
$queue = new \AMQPQueue($channel);
$queue->setName('global');

$messageProvider = new PeclPackageMessageProvider($queue);

Once it's done you need to create a Processor to process messages retrieved from the broker. This processor must implement Swarrot\Processor\ProcessorInterface. For example:

use Swarrot\Processor\ProcessorInterface;
use Swarrot\Broker\Message;

class Processor implements ProcessorInterface {
    public function process(Message $message, array $options) {
        echo sprintf("Consume message #%d\n", $message->getId());
    }
}

You now have a Swarrot\Broker\MessageProviderInterface to retrieve messages and a Processor to process them. So, ask the Swarrot\Consumerto do it's job :

use Swarrot\Message;

$consumer = new Consumer($messageProvider, $processor);
$consumer->consume();

Heavily inspired by stackphp/builder you can use Swarrot\Processor\Stack\Builder to stack your processors. Using the built in processors or by creating your own, you can extend the behavior of your base processor. In this example, your processor is decorated by 2 others one. The ExceptionCatcherProcessor which decorate your own with a try/catch block and the MaxMessagesProcessor which stop your worker when some messages have been consumed.

use Swarrot\Processor\ProcessorInterface;
use Swarrot\Broker\Message;

class Processor implements ProcessorInterface {
    public function process(Message $message, array $options) {
        echo sprintf("Consume message #%d\n", $message->getId());
    }
}

$stack = (new \Swarrot\Processor\Stack\Builder())
    ->push('Swarrot\Processor\MaxMessages\MaxMessagesProcessor', new Logger())
    ->push('Swarrot\Processor\ExceptionCatcher\ExceptionCatcherProcessor')
    ->push('Swarrot\Processor\Ack\AckProcessor', $messageProvider)
;

$processor = $stack->resolve(new Processor());

Here is an illustration to show you what append when this order is used:

• AckProcessor
• Doctrine related processors (thanks to Adrien Brault)
• ExceptionCatcherProcessor
• InstantRetryProcessor
• MaxExecutionTimeProcessor (thanks to Remy Lemeunier)
• MaxMessagesProcessor (thanks to Remy Lemeunier)
• RetryProcessor
• SignalHandlerProcessor

To create your own processor and be able to use it with the StackProcessor, you just need to implement ProcessorInterface and to take another ProcessorInterface as first argument in constructor.

• stackphp/builder

Swarrot is released under the MIT License. See the bundled LICENSE file for details.