Add configurable processor class support

docs/en/index.rst

@@ -54,6 +54,10 @@ The following configuration should be present in the config array of your **conf
             // The name of an event listener class to associate with the worker
             'listener' => \App\Listener\WorkerListener::class,
 
+            // (optional) The processor class to use for processing messages.
+            // Must implement Interop\Queue\Processor. Defaults to Cake\Queue\Queue\Processor
+            'processor' => \App\Queue\CustomProcessor::class,
+
             // The amount of time in milliseconds to sleep if no jobs are currently available. default: 10000
             'receiveTimeout' => 10000,
 
@@ -119,14 +123,14 @@ A simple job that logs received messages would look like::
 
         /**
          * The maximum number of times the job may be attempted. (optional property)
-         * 
+         *
          * @var int|null
          */
         public static $maxAttempts = 3;
 
         /**
          * Whether there should be only one instance of a job on the queue at a time. (optional property)
-         * 
+         *
          * @var bool
          */
         public static $shouldBeUnique = false;
@@ -299,7 +303,7 @@ queue jobs, you can use the ``QueueTransport``. In your application's
 
     return [
         // ... other configuration
-        'EmailTransport' => [            
+        'EmailTransport' => [
             'default' => [
                 'className' => MailTransport::class,
                 // Configuration for MailTransport.
@@ -323,6 +327,153 @@ With this configuration in place, any time you send an email with the ``default`
 email profile CakePHP will generate a queue message. Once that queue message is
 processed the default ``MailTransport`` will be used to deliver the email messages.
 
+Custom Processors
+================
+
+You can customize how messages are processed by specifying a custom processor class
+in your queue configuration. Custom processors must implement the ``Interop\Queue\Processor``
+interface.
+
+Example custom processor that extends the main Processor::
+
+    <?php
+    declare(strict_types=1);
+
+    namespace App\Queue;
+
+    use Cake\Core\ContainerInterface;
+    use Cake\Queue\Job\Message;
+    use Cake\Queue\Queue\Processor;
+    use Enqueue\Consumption\Result;
+    use Error;
+    use Interop\Queue\Context;
+    use Interop\Queue\Message as QueueMessage;
+    use Interop\Queue\Processor as InteropProcessor;
+    use Psr\Log\LoggerInterface;
+    use RuntimeException;
+    use Throwable;
+
+    /**
+     * Timed Processor
+     *
+     * Extends the original Processor to add timing metrics to all events.
+     */
+    class TimedProcessor extends Processor
+    {
+        /**
+         * Constructor
+         *
+         * @param \Psr\Log\LoggerInterface|null $logger Logger instance
+         * @param \Cake\Core\ContainerInterface|null $container DI container instance
+         */
+        public function __construct(?LoggerInterface $logger = null, ?ContainerInterface $container = null)
+        {
+            parent::__construct($logger, $container);
+        }
+
+        /**
+         * Process message with timing
+         *
+         * @param \Interop\Queue\Message $message Message
+         * @param \Interop\Queue\Context $context Context
+         * @return object|string
+         */
+        public function process(QueueMessage $message, Context $context): string|object
+        {
+            $this->dispatchEvent('Processor.message.seen', ['queueMessage' => $message]);
+
+            $jobMessage = new Message($message, $context, $this->container);
+            try {
+                $jobMessage->getCallable();
+            } catch (RuntimeException | Error $e) {
+                $this->logger->debug('Invalid callable for message. Rejecting message from queue.');
+                $this->dispatchEvent('Processor.message.invalid', ['message' => $jobMessage]);
+
+                return InteropProcessor::REJECT;
+            }
+
+            $startTime = microtime(true) * 1000;
+            $this->dispatchEvent('Processor.message.start', ['message' => $jobMessage]);
+
+            try {
+                $response = $this->processMessage($jobMessage);
+            } catch (Throwable $e) {
+                $message->setProperty('jobException', $e);
+
+                $this->logger->debug(sprintf('Message encountered exception: %s', $e->getMessage()));
+                $this->dispatchEvent('Processor.message.exception', [
+                    'message' => $jobMessage,
+                    'exception' => $e,
+                    'duration' => (int)((microtime(true) * 1000) - $startTime),
+                ]);
+
+                return Result::requeue('Exception occurred while processing message');
+            }
+
+            $duration = (int)((microtime(true) * 1000) - $startTime);
+
+            if ($response === InteropProcessor::ACK) {
+                $this->logger->debug('Message processed successfully');
+                $this->dispatchEvent('Processor.message.success', [
+                    'message' => $jobMessage,
+                    'duration' => $duration,
+                ]);
+
+                return InteropProcessor::ACK;
+            }
+
+            if ($response === InteropProcessor::REJECT) {
+                $this->logger->debug('Message processed with rejection');
+                $this->dispatchEvent('Processor.message.reject', [
+                    'message' => $jobMessage,
+                    'duration' => $duration,
+                ]);
+
+                return InteropProcessor::REJECT;
+            }
+
+            $this->logger->debug('Message processed with failure, requeuing');
+            $this->dispatchEvent('Processor.message.failure', [
+                'message' => $jobMessage,
+                'duration' => $duration,
+            ]);
+
+            return InteropProcessor::REQUEUE;
+        }
+    }
+
+Configuration example::
+
+    'Queue' => [
+        'default' => [
+            'url' => 'redis://localhost:6379',
+            'queue' => 'default',
+            // No processor specified - uses default Processor class
+        ],
+        'timed' => [
+            'url' => 'redis://localhost:6379',
+            'queue' => 'timed',
+            'processor' => \App\Queue\TimedProcessor::class, // Custom processor with timing
+        ],
+    ],
+
+**Note**: If no processor is specified in the configuration, the default
+``Cake\Queue\Queue\Processor`` class will be used. Custom processors are useful
+for adding custom logging, metrics collection, or specialized message handling.
+
+**Important**: The `--processor` command line option is different from the `processor` configuration option:
+
+- **Configuration `processor`**: Specifies the processor class to use for processing messages
+- **Command line `--processor`**: Specifies the processor name for Enqueue topic binding (used in `bindTopic()`)
+
+Example usage::
+
+    # Use custom processor class from config
+    bin/cake queue worker --config=timed
+
+    # Use custom processor class AND specify topic binding name
+    bin/cake queue worker --config=timed --processor=my-topic-processor
+
 Run the worker
 ==============
 
@@ -336,7 +487,7 @@ This shell can take a few different options:
 
 - ``--config`` (default: default): Name of a queue config to use
 - ``--queue`` (default: default): Name of queue to bind to
-- ``--processor`` (default: ``null``): Name of processor to bind to
+- ``--processor`` (default: ``null``): Name of processor to bind to (for Enqueue topic binding, not the processor class)
 - ``--logger`` (default: ``stdout``): Name of a configured logger
 - ``--max-jobs`` (default: ``null``): Maximum number of jobs to process. Worker will exit after limit is reached.
 - ``--max-runtime`` (default: ``null``): Maximum number of seconds to run. Worker will exit after limit is reached.
@@ -370,7 +521,7 @@ Requeue Failed Jobs
 
 Push jobs back onto the queue and remove them from the ``queue_failed_jobs``
 table. If a job fails to requeue it is not guaranteed that the job was not run.
- 
+
 .. code-block:: bash
 
     bin/cake queue requeue

src/Command/WorkerCommand.php

@@ -34,6 +34,7 @@
 use Enqueue\Consumption\Extension\LimitConsumptionTimeExtension;
 use Enqueue\Consumption\Extension\LoggerExtension;
 use Enqueue\Consumption\ExtensionInterface;
+use Interop\Queue\Processor as InteropProcessor;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
 
@@ -170,6 +171,34 @@ protected function getLogger(Arguments $args): LoggerInterface
         return $logger ?? new NullLogger();
     }
 
+    /**
+     * Creates and returns a Processor object
+     *
+     * @param \Cake\Console\Arguments $args Arguments
+     * @param \Cake\Console\ConsoleIo $io ConsoleIo
+     * @param \Psr\Log\LoggerInterface $logger Logger instance
+     * @return \Interop\Queue\Processor
+     */
+    protected function getProcessor(Arguments $args, ConsoleIo $io, LoggerInterface $logger): InteropProcessor
+    {
+        $configKey = (string)$args->getOption('config');
+        $config = QueueManager::getConfig($configKey);
+
+        $processorClass = $config['processor'] ?? Processor::class;
+
+        if (!class_exists($processorClass)) {
+            $io->error(sprintf(sprintf('Processor class %s not found', $processorClass)));
+            $this->abort();
+        }
+
+        if (!is_subclass_of($processorClass, InteropProcessor::class)) {
+            $io->error(sprintf(sprintf('Processor class %s must implement Interop\Queue\Processor', $processorClass)));
+            $this->abort();
+        }
+
+        return new $processorClass($logger, $this->container);
+    }
+
     /**
      * @param \Cake\Console\Arguments $args Arguments
      * @param \Cake\Console\ConsoleIo $io ConsoleIo
@@ -184,7 +213,7 @@ public function execute(Arguments $args, ConsoleIo $io): int
         }
 
         $logger = $this->getLogger($args);
-        $processor = new Processor($logger, $this->container);
+        $processor = $this->getProcessor($args, $io, $logger);
         $extension = $this->getQueueExtension($args, $logger);
 
         $hasListener = Configure::check(sprintf('Queue.%s.listener', $config));
@@ -197,7 +226,10 @@ public function execute(Arguments $args, ConsoleIo $io): int
 
             /** @var \Cake\Event\EventListenerInterface $listener */
             $listener = new $listenerClassName();
-            $processor->getEventManager()->on($listener);
+
+            if ($processor instanceof Processor) {
+                $processor->getEventManager()->on($listener);
+            }
         }
         $client = QueueManager::engine($config);
         $queue = $args->getOption('queue')