[RedisMessengerBridge] Add a delete_after_ack option to automatically clean up processed messages from memory

src/Symfony/Component/Messenger/Bridge/Redis/CHANGELOG.md

@@ -9,3 +9,5 @@ CHANGELOG
  * Deprecated use of invalid options
  * Added ability to receive of old pending messages with new `redeliver_timeout`
    and `claim_interval` options.
+ * Added a `delete_after_ack` option to the DSN as an alternative to
+   `stream_max_entries` to avoid leaking memory.

src/Symfony/Component/Messenger/Bridge/Redis/Tests/Transport/ConnectionTest.php

@@ -307,6 +307,21 @@ class ConnectionTest extends TestCase
         $connection->add('1', []);
     }
 
+    public function testDeleteAfterAck()
+    {
+        $redis = $this->getMockBuilder(\Redis::class)->disableOriginalConstructor()->getMock();
+
+        $redis->expects($this->exactly(1))->method('xack')
+            ->with('queue', 'symfony', ['1'])
+            ->willReturn(1);
+        $redis->expects($this->exactly(1))->method('xdel')
+            ->with('queue', ['1'])
+            ->willReturn(1);
+
+        $connection = Connection::fromDsn('redis://localhost/queue?delete_after_ack=true', [], $redis); // 1 = always
+        $connection->ack('1');
+    }
+
     public function testLastErrorGetsCleared()
     {
         $redis = $this->getMockBuilder(\Redis::class)->disableOriginalConstructor()->getMock();

src/Symfony/Component/Messenger/Bridge/Redis/Transport/Connection.php

@@ -32,6 +32,7 @@ class Connection
         'group' => 'symfony',
         'consumer' => 'consumer',
         'auto_setup' => true,
+        'delete_after_ack' => false,
         'stream_max_entries' => 0, // any value higher than 0 defines an approximate maximum number of stream entries
         'dbindex' => 0,
         'tls' => false,
@@ -49,6 +50,7 @@ class Connection
     private $redeliverTimeout;
     private $nextClaim = 0;
     private $claimInterval;
+    private $deleteAfterAck;
     private $couldHavePendingMessages = true;
 
     public function __construct(array $configuration, array $connectionCredentials = [], array $redisOptions = [], \Redis $redis = null)
@@ -81,6 +83,7 @@ class Connection
         $this->queue = $this->stream.'__queue';
         $this->autoSetup = $configuration['auto_setup'] ?? self::DEFAULT_OPTIONS['auto_setup'];
         $this->maxEntries = $configuration['stream_max_entries'] ?? self::DEFAULT_OPTIONS['stream_max_entries'];
+        $this->deleteAfterAck = $configuration['delete_after_ack'] ?? self::DEFAULT_OPTIONS['delete_after_ack'];
         $this->redeliverTimeout = ($configuration['redeliver_timeout'] ?? self::DEFAULT_OPTIONS['redeliver_timeout']) * 1000;
         $this->claimInterval = $configuration['claim_interval'] ?? self::DEFAULT_OPTIONS['claim_interval'];
     }
@@ -114,6 +117,12 @@ class Connection
             unset($redisOptions['stream_max_entries']);
         }
 
+        $deleteAfterAck = null;
+        if (\array_key_exists('delete_after_ack', $redisOptions)) {
+            $deleteAfterAck = filter_var($redisOptions['delete_after_ack'], FILTER_VALIDATE_BOOLEAN);
+            unset($redisOptions['delete_after_ack']);
+        }
+
         $dbIndex = null;
         if (\array_key_exists('dbindex', $redisOptions)) {
             $dbIndex = filter_var($redisOptions['dbindex'], FILTER_VALIDATE_INT);
@@ -144,6 +153,7 @@ class Connection
             'consumer' => $redisOptions['consumer'] ?? null,
             'auto_setup' => $autoSetup,
             'stream_max_entries' => $maxEntries,
+            'delete_after_ack' => $deleteAfterAck,
             'dbindex' => $dbIndex,
             'redeliver_timeout' => $redeliverTimeout,
             'claim_interval' => $claimInterval,
@@ -314,6 +324,9 @@ class Connection
     {
         try {
             $acknowledged = $this->connection->xack($this->stream, $this->group, [$id]);
+            if ($this->deleteAfterAck) {
+                $acknowledged = $this->connection->xdel($this->stream, [$id]);
+            }
         } catch (\RedisException $e) {
             throw new TransportException($e->getMessage(), 0, $e);
         }
@@ -408,6 +421,18 @@ class Connection
             $this->connection->clearLastError();
         }
 
+        if ($this->deleteAfterAck) {
+            $groups = $this->connection->xinfo('GROUPS', $this->stream);
+            if (
+                // support for Redis extension version 5+
+                (\is_array($groups) && 1 < \count($groups))
+                // support for Redis extension version 4.x
+                || (\is_string($groups) && substr_count($groups, '"name"'))
+            ) {
+                throw new LogicException(sprintf('More than one group exists for stream "%s", delete_after_ack can not be enabled as it risks deleting messages before all groups could consume them.', $this->stream));
+            }
+        }
+
         $this->autoSetup = false;
     }