Added control abstractions for transaction demarcation.

lib/Doctrine/DBAL/Connection.php

@@ -19,7 +19,7 @@
 
 namespace Doctrine\DBAL;
 
-use PDO, Closure,
+use PDO, Closure, Exception,
     Doctrine\DBAL\Types\Type,
     Doctrine\DBAL\Driver\Connection as DriverConnection,
     Doctrine\Common\EventManager,
@@ -705,6 +705,28 @@ class Connection implements DriverConnection
         return $this->_conn->lastInsertId($seqName);
     }
 
+    /**
+     * Executes a function in a transaction.
+     *
+     * The function gets passed this Connection instance as an (optional) parameter.
+     *
+     * If an exception occurs during execution of the function or transaction commit,
+     * the transaction is rolled back and the exception re-thrown.
+     *
+     * @param Closure $func The function to execute transactionally.
+     */
+    public function transactional(Closure $func)
+    {
+        $this->beginTransaction();
+        try {
+            $func($this);
+            $this->commit();
+        } catch (Exception $e) {
+            $this->rollback();
+            throw $e;
+        }
+    }
+
     /**
      * Starts a transaction by suspending auto-commit mode.
      *

lib/Doctrine/ORM/EntityManager.php

@@ -19,7 +19,8 @@
 
 namespace Doctrine\ORM;
 
-use Doctrine\Common\EventManager,
+use Closure, Exception,
+    Doctrine\Common\EventManager,
     Doctrine\DBAL\Connection,
     Doctrine\ORM\Mapping\ClassMetadata,
     Doctrine\ORM\Mapping\ClassMetadataFactory,
@@ -176,6 +177,32 @@ class EntityManager
         $this->_conn->beginTransaction();
     }
 
+    /**
+     * Executes a function in a transaction.
+     *
+     * The function gets passed this EntityManager instance as an (optional) parameter.
+     *
+     * {@link flush} is invoked prior to transaction commit.
+     *
+     * If an exception occurs during execution of the function or flushing or transaction commit,
+     * the transaction is rolled back, the EntityManager closed and the exception re-thrown.
+     *
+     * @param Closure $func The function to execute transactionally.
+     */
+    public function transactional(Closure $func)
+    {
+        $this->_conn->beginTransaction();
+        try {
+            $func($this);
+            $this->flush();
+            $this->_conn->commit();
+        } catch (Exception $e) {
+            $this->close();
+            $this->_conn->rollback();
+            throw $e;
+        }
+    }
+
     /**
      * Commits a transaction on the underlying database connection.
      *

lib/Doctrine/ORM/UnitOfWork.php

@@ -1290,6 +1290,8 @@ class UnitOfWork implements PropertyChangedListener
      * @return object The managed copy of the entity.
      * @throws OptimisticLockException If the entity uses optimistic locking through a version
      *         attribute and the version check against the managed copy fails.
+     *
+     * @todo Require active transaction!? OptimisticLockException may result in undefined state!?
      */
     public function merge($entity)
     {

tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php

@@ -59,6 +59,16 @@ class ConnectionTest extends \Doctrine\Tests\DbalFunctionalTestCase
             $this->_conn->rollback();
             $this->assertEquals(0, $this->_conn->getTransactionNestingLevel());
         }
+
+        $this->assertEquals(0, $this->_conn->getTransactionNestingLevel());
+        try {
+            $this->_conn->transactional(function($conn) {
+                $conn->executeQuery("select 1");
+                throw new \RuntimeException("Ooops!");
+            });
+        } catch (\RuntimeException $expected) {
+            $this->assertEquals(0, $this->_conn->getTransactionNestingLevel());
+        }
     }
     
 }
\ No newline at end of file

tests/Doctrine/Tests/ORM/Functional/BasicFunctionalTest.php

@@ -643,9 +643,10 @@ class BasicFunctionalTest extends \Doctrine\Tests\OrmFunctionalTestCase
         $address->zip = '12345';
         
         $user->setAddress($address);
-        
-        $this->_em->persist($user);
-        $this->_em->flush();
+
+        $this->_em->transactional(function($em) use($user) {
+            $em->persist($user);
+        });
         $this->_em->clear();
         
         //$this->_em->getConnection()->getConfiguration()->setSQLLogger(new \Doctrine\DBAL\Logging\EchoSQLLogger);
@@ -661,7 +662,6 @@ class BasicFunctionalTest extends \Doctrine\Tests\OrmFunctionalTestCase
         $this->assertEquals('Germany', $address2->country);
         $this->assertEquals('Berlin', $address2->city);
         $this->assertEquals('12345', $address2->zip);
-        
     }
     
     //DRAFT OF EXPECTED/DESIRED BEHAVIOR