Fatal Exception

README.md

@@ -205,6 +205,11 @@ If an exception is triggered in the `Consumer`, a `nack` will be sent instead to
 
 Note: if your consumer callback throws an exception implementing the `RetryableExceptionInterface` interface, the `nack` message will be sent with the "requeue" flag. The message will be requeued.
 
+Note: if your consumer callback throws an exception implementing the `FatalExceptionInterface` interface, the exception will be propagated by the consumer (hence leading to the crash of the consumer script). Otherwise, consumer will continue processing messages.
+
+Exceptions are logged by default using the error_log function. You can override this behaviour by passing a PSR-3 compliant logger to the `AbstractConsumer` constructor.
+
+
 Writing your consumer as a class
 --------------------------------
 

composer.json

@@ -16,7 +16,9 @@
 	],
 	"require" : {
 		"php" : ">=5.6",
-		"php-amqplib/php-amqplib": "^2.6.3"
+		"php-amqplib/php-amqplib": "^2.6.3",
+		"psr/log": "^1",
+		"mouf/utils.log.psr.errorlog_logger": "^2"
 	},
     "require-dev" : {
 	    "phpunit/phpunit": "^5.4.6",

src/AbstractConsumer.php

@@ -2,19 +2,41 @@
 
 namespace Mouf\AmqpClient;
 
+use Mouf\Utils\Log\Psr\ErrorLogLogger;
+use Psr\Log\LoggerInterface;
+
 abstract class AbstractConsumer implements ConsumerInterface
 {
     use ConsumerTrait;
 
+    private $logger;
+
+    public function __construct(LoggerInterface $logger = null)
+    {
+        $this->logger = $logger ?: new ErrorLogLogger();
+    }
+
     public function callback($msg)
     {
         try {
             $this->onMessageReceived($msg);
 
             $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);
         } catch (RetryableExceptionInterface $e) {
+            $this->logger->error("Exception caught while consuming message.", [
+                'exception' => $e
+            ]);
+            if ($e instanceof FatalExceptionInterface) {
+                throw $e;
+            }
             $msg->delivery_info['channel']->basic_nack($msg->delivery_info['delivery_tag'], true, true);
         } catch (\Exception $e) {
+            $this->logger->error("Exception caught while consuming message.", [
+                'exception' => $e
+            ]);
+            if ($e instanceof FatalExceptionInterface) {
+                throw $e;
+            }
             $msg->delivery_info['channel']->basic_nack($msg->delivery_info['delivery_tag'], true, false);
         }
     }

src/FatalExceptionInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Mouf\AmqpClient;
+
+/**
+ * When an exception implementing this interface is thrown, the consumer will propagate the exception (so the script
+ * will stop). Useful to halt a consumer script if the database connection has timed out.
+ */
+interface FatalExceptionInterface
+{
+    /**
+     * Exception is propagated if isFatal returns true.
+     * @return bool
+     */
+    public function isFatal();
+}