feat/incompatible-with-neo4j-php/neo4j-php-client-3.4.0 (#98)

feat/incompatible-with-neo4j-php/neo4j-php-client-3.4.0: Created custom retry logic instead of relying on TransactionHelper

Author: zaeem2331

phpunit.xml.dist

@@ -1,13 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-        bootstrap="./vendor/autoload.php"
+        bootstrap="./tests/bootstrap.php"
         colors="true"
         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
         failOnWarning="true"
         beStrictAboutOutputDuringTests="true"
+        convertDeprecationsToExceptions="false"
 >
   <testsuites>
+    <testsuite name="Unit tests">
+      <directory suffix="Test.php">./tests/Unit</directory>
+    </testsuite>
     <testsuite name="Functional tests">
       <directory suffix="Test.php">./tests/Functional</directory>
     </testsuite>

src/Decorators/SymfonySession.php

@@ -3,24 +3,33 @@
 namespace Neo4j\Neo4jBundle\Decorators;
 
 use Laudis\Neo4j\Basic\Session;
-use Laudis\Neo4j\Common\TransactionHelper;
+use Laudis\Neo4j\Contracts\ConnectionPoolInterface;
+use Laudis\Neo4j\Contracts\CypherSequence;
 use Laudis\Neo4j\Contracts\SessionInterface;
 use Laudis\Neo4j\Databags\Bookmark;
+use Laudis\Neo4j\Databags\SessionConfiguration;
 use Laudis\Neo4j\Databags\Statement;
 use Laudis\Neo4j\Databags\SummarizedResult;
 use Laudis\Neo4j\Databags\TransactionConfiguration;
+use Laudis\Neo4j\Enum\AccessMode;
+use Laudis\Neo4j\Exception\Neo4jException;
 use Laudis\Neo4j\Types\CypherList;
 use Neo4j\Neo4jBundle\EventHandler;
 use Neo4j\Neo4jBundle\Factories\SymfonyDriverFactory;
 
 final class SymfonySession implements SessionInterface
 {
+    private const MAX_RETRIES = 3;
+    private const ROLLBACK_CLASSIFICATIONS = ['ClientError', 'TransientError', 'DatabaseError'];
+
     public function __construct(
         private readonly Session $session,
         private readonly EventHandler $handler,
         private readonly SymfonyDriverFactory $factory,
         private readonly string $alias,
         private readonly string $schema,
+        private readonly SessionConfiguration $config,
+        private readonly ConnectionPoolInterface $pool,
     ) {
     }
 
@@ -76,10 +85,7 @@ public function beginTransaction(?iterable $statements = null, ?TransactionConfi
     #[\Override]
     public function writeTransaction(callable $tsxHandler, ?TransactionConfiguration $config = null)
     {
-        return TransactionHelper::retry(
-            fn () => $this->beginTransaction(config: $config),
-            $tsxHandler
-        );
+        return $this->retryTransaction($tsxHandler, $config, read: false);
     }
 
     /**
@@ -92,8 +98,7 @@ public function writeTransaction(callable $tsxHandler, ?TransactionConfiguration
     #[\Override]
     public function readTransaction(callable $tsxHandler, ?TransactionConfiguration $config = null)
     {
-        // TODO: create read transaction here.
-        return $this->writeTransaction($tsxHandler, $config);
+        return $this->retryTransaction($tsxHandler, $config, read: true);
     }
 
     /**
@@ -114,4 +119,68 @@ public function getLastBookmark(): Bookmark
     {
         return $this->session->getLastBookmark();
     }
+
+    /**
+     * Custom retry transaction logic to replace TransactionHelper.
+     *
+     * @template HandlerResult
+     *
+     * @param callable(SymfonyTransaction):HandlerResult $tsxHandler
+     *
+     * @return HandlerResult
+     */
+    private function retryTransaction(callable $tsxHandler, ?TransactionConfiguration $config, bool $read)
+    {
+        $attempt = 0;
+
+        while (true) {
+            ++$attempt;
+            $transaction = null;
+
+            try {
+                $sessionConfig = $this->config->withAccessMode($read ? AccessMode::READ() : AccessMode::WRITE());
+                $transaction = $this->startTransaction($config, $sessionConfig);
+
+                $result = $tsxHandler($transaction);
+
+                self::triggerLazyResult($result);
+                $transaction->commit();
+
+                return $result;
+            } catch (Neo4jException $e) {
+                if ($transaction && !in_array($e->getClassification(), self::ROLLBACK_CLASSIFICATIONS)) {
+                    $transaction->rollback();
+                }
+
+                if ('NotALeader' === $e->getTitle()) {
+                    $this->pool->close();
+                } elseif ('TransientError' !== $e->getClassification()) {
+                    throw $e;
+                }
+
+                if ($attempt >= self::MAX_RETRIES) {
+                    throw $e;
+                }
+
+                usleep(100_000);
+            }
+        }
+    }
+
+    private static function triggerLazyResult(mixed $tbr): void
+    {
+        if ($tbr instanceof CypherSequence) {
+            $tbr->preload();
+        }
+    }
+
+    private function startTransaction(?TransactionConfiguration $config, SessionConfiguration $sessionConfig): SymfonyTransaction
+    {
+        return $this->factory->createTransaction(
+            session: $this->session,
+            config: $config,
+            alias: $this->alias,
+            schema: $this->schema
+        );
+    }
 }

src/DependencyInjection/Neo4jExtension.php

@@ -11,7 +11,6 @@
 use Neo4j\Neo4jBundle\EventHandler;
 use Neo4j\Neo4jBundle\EventListener\Neo4jProfileListener;
 use Psr\Log\LoggerInterface;
-use Psr\Log\LogLevel;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\ContainerInterface;

src/Factories/SymfonyDriverFactory.php

@@ -54,6 +54,8 @@ public function createSession(
             factory: $this,
             alias: $alias,
             schema: $schema,
+            config: $config ?? new SessionConfiguration(),
+            pool: $this->getPoolFromDriver($driver),
         );
     }
 
@@ -70,6 +72,21 @@ public function createDriver(
         );
     }
 
+    private function getPoolFromDriver(Driver $driver): \Laudis\Neo4j\Contracts\ConnectionPoolInterface
+    {
+        // Use reflection to access the private pool property from the underlying driver
+        $reflection = new \ReflectionClass($driver);
+        $driverProperty = $reflection->getProperty('driver');
+        $driverProperty->setAccessible(true);
+        $underlyingDriver = $driverProperty->getValue($driver);
+
+        $underlyingReflection = new \ReflectionClass($underlyingDriver);
+        $poolProperty = $underlyingReflection->getProperty('pool');
+        $poolProperty->setAccessible(true);
+
+        return $poolProperty->getValue($underlyingDriver);
+    }
+
     private function generateTransactionId(): string
     {
         if ($this->uuidFactory) {

tests/App/Controller/TestController.php

@@ -14,6 +14,11 @@ public function __construct(private readonly LoggerInterface $logger)
     {
     }
 
+    public function index(): Response
+    {
+        return $this->render('index.html.twig');
+    }
+
     public function runOnClient(ClientInterface $client): Response
     {
         $client->run('MATCH (n {foo: $bar}) RETURN n', ['bar' => 'baz']);

tests/App/config/routes.yaml

@@ -1,3 +1,6 @@
+index:
+  path: /
+  controller: Neo4j\Neo4jBundle\Tests\App\Controller\TestController::index
 run-on-client:
   path: /client
   controller: Neo4j\Neo4jBundle\Tests\App\Controller\TestController::runOnClient
@@ -9,8 +12,8 @@ run-on-transaction:
   controller: Neo4j\Neo4jBundle\Tests\App\Controller\TestController::runOnTransaction
 
 web_profiler_wdt:
-  resource: '@WebProfilerBundle/Resources/config/routing/wdt.xml'
+  resource: '@WebProfilerBundle/Resources/config/routing/wdt.php'
   prefix: /_wdt
 web_profiler_profiler:
-  resource: '@WebProfilerBundle/Resources/config/routing/profiler.xml'
+  resource: '@WebProfilerBundle/Resources/config/routing/profiler.php'
   prefix: /_profiler4