Example usage | Zend_Queue Programmer's Reference Guide | Adapters

# Framework

The Zend_Queue is a proxy that hides the details of the queue services. The queue services are represented by Zend_Queue_Adapter_<service>. For example, Zend_Queue_Adapter_Db is a queue that will use database tables to store and retrieve messages.

Below is an example for using database tables for a queuing system:

1. $options = array(
2. 'name' => 'queue1',
3. 'driverOptions' => array(
4. 'host' => '127.0.0.1',
5. 'port' => '3306',
6. 'username' => 'queue',
7. 'password' => 'queue',
8. 'dbname' => 'queue',
9. 'type' => 'pdo_mysql'
10. )
11. );
13. // Create a database queue.
14. // Zend_Queue will prepend Zend_Queue_Adapter_ to 'Db' for the class name.
15. $queue = new Zend_Queue('Db', $options);

The Zend_Queue constructor will create a Zend_Queue_Adapter_Db and initialize the adapter with the configuration settings.

The accepted configuration settings for each adapter are provided in the adapter notes.

Zend_Queue returns messages using the class Zend_Queue_Message_Iterator, which is an implementation of SPL Iterator and Countable. Zend_Queue_Message_Iterator contains an array of Zend_Queue_Message objects.

1. $messages = $queue->receive(5);
2. foreach ($messages as $i => $message) {
3. echo "$i) Message => ", $message->body, "\n";
4. }

Any exceptions thrown are of class Zend_Queue_Exception.

# Introduction

Zend_Queue is a proxy class that represents an adapter.

The send(), count($queue), and receive() methods are employed by each adapter to interact with queues.

The createQueue(), deleteQueue() methods are used to manage queues.

# Commonality among adapters

The queue services supported by Zend_Queue do not all support the same functions. For example, Zend_Queue_Adapter_Array, Zend_Queue_Adapter_Db, support all functions, while Zend_Queue_Adapter_Activemq does not support queue listing, queue deletion, or counting of messages.

You can determine what functions are supported by using Zend_Queue::isSupported() or Zend_Queue::getCapabilities().

- createQueue() - create a queue

- deleteQueue() - delete a queue

- send() - send a message

  send() is not available in all adapters; the Zend_Queue_Adapter_Null does not support send().

- receive() - receive messages

  receive() is not available in all adapters; the Zend_Queue_Adapter_Null does not support receive().

- deleteMessage() - delete a message

- count() - count the number of messages in a queue

- isExists() - checks the existence of a queue

receive() methods are employed by each adapter to interact with queues.

The createQueue() and deleteQueue() methods are used to manage queues.

Example usage | Zend_Queue Programmer's Reference Guide | Adapters