Lithium Queue Plugin

by Christopher Garvis & Olivier Louvignes

Description

This plugin provides a simple way to handle work queues, it currently supports:

• AMQP
• Beanstalk
• Gearman in the gearman branch

Installation

1. To enable the library add the following line at the end of app/config/bootstrap/libraries.php:

   Libraries::add('li3_queue');

2. Then configure your queues in app/config/bootstrap/queues.php:

   use li3_queue\storage\Queue;
   
   Queue::config(array('default' => array(
       'adapter' => 'Beanstalk',
       'host' => '127.0.0.1',
       'port' => 11300
   )));

3. Update app/config/bootstrap.php to include this new configuration file:

   /**
    * Include this file if your application uses one or more queues.
    */
   require __DIR__ . '/bootstrap/queues.php';

4. You can now use your configured queues in your application:

   use li3_queue\storage\Queue;

5. There is some known bugs with several PHP versions regarding the stream_get_line function that can incorrectly fail to return on \r\n EOL packets. Unfortunately this bug affects the 12.04 shipped PHP version (php5.3.10-1).

Settings

1. If autoConfirm is true messages will be automatically confirmed on the server and whenever you use Queue::read() or Queue::consume(). This means you will not need to use $message->confirm() and will be unable to requeue using $message->requeue().

AMQP interface

Configuration

Configuration for your queue will go in app/config/bootstrap/queues.php and can contain any of the following options:

1. Basic

Queue::config(array(
    'default' => array(
        'adapter' => 'AMQP',
        'host' => '127.0.0.1',
        'login' => 'guest',
        'password' => 'guest',
        'port' => 5672,
        'vhost' => '/',
        'exchange' => 'li3.default',
        'queue' => 'li3.default',
        'routingKey' => null,
        'autoConfirm' => false,
        'cacert' => null,
        'cert' => null,
        'key' => null,
        'verify' => true
    )
));

2. Publish/Subscribe

To configure the AMQP adapter to function as publish/subscribe, you can create multiple queue configs in the following way:

Queue::config(array(
    'publish' => array(
        'adapter' => 'AMQP',
        'exchangeType' => AMQP_EX_TYPE_FANOUT,
        'exchange' => 'li3.publish',
        'queue' => false,
    ),
    'subscribe.1' => array(
        'adapter' => 'AMQP',
        'exchangeType' => AMQP_EX_TYPE_FANOUT,
        'exchange' => 'li3.publish',
        'queue' => 'li3.subscribe.1'
    ),
    'subscribe.2' => array(
        'adapter' => 'AMQP',
        'exchangeType' => AMQP_EX_TYPE_FANOUT,
        'exchange' => 'li3.publish',
        'queue' => 'li3.subscribe.2'
    )
));

Additional notes:

1. routingKey when null will be set by default to the same value as queue, setting the routing key will only be needed in advanced configurations

Beanstalk interface

Configuration

Configuration for your queue will go in app/config/bootstrap/queues.php and can contain any of the following options:

Queue::config(array(
    'default' => array(
        'adapter' => 'Beanstalk',
        'host' => '127.0.0.1',
        'port' => 11300,
        'tube' => 'default',
        'autoConfirm' => false
    )
));

• Check source for additional configuration.

Usage

1. Write a message

   Queue::write('default', 'message');

2. Read a message

   $message = Queue::read('default');

3. Confirm or requeue a message

   Once you've read a message from the queue you will either need to confirm it's success using:

   $message->confirm();

   Or requeue your message using:

   $message->requeue();

4. Consume messages

   Queue::consume('default', function($message) {
       // Do something with message
       if($success) {
           // Confirm message
           $message->confirm();
       }
       // Requeue message
       $message->requeue();
   });

   Consuming messages is a blocking action which will retrieve the next available message and pass it off to the callback. Returning false in the callback will break out of the consume.

Bugs & Contribution

Patches welcome! Send a pull request.

Post issues on Github

License

Copyright (c) 2012, Union of RAD http://union-of-rad.org
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
        this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
        this list of conditions and the following disclaimer in the documentation
        and/or other materials provided with the distribution.
    * Neither the name of Lithium, Union of Rad, nor the names of its contributors
        may be used to endorse or promote products derived from this software
        without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.