initial support for settings savepoints in nested transactions

lib/Doctrine/DBAL/Connection.php

@@ -740,6 +740,23 @@ class Connection implements DriverConnection
         }
     }
 
+    /**
+     * Returns the savepoint name to use for nested transactions are false if they are not supported
+     * "savepointFormat" parameter is not set
+     *
+     * @return mixed a string with the savepoint name or false
+     */
+    protected function _getNestedTransactionSavePointName($transactionNestingLevel) {
+        //TODO this should be configured not hardcoded, but how to do user configuration
+        $this->_params['savepointFormat'] = 'DOCTRINE2_SAVEPOINT_%s';
+
+        if ($this->_platform->supportsSavepoints() && !empty($this->_params['savepointFormat'])) {
+            return sprintf($this->_params['savepointFormat'], $this->_transactionNestingLevel);
+        }
+
+        return false;
+    }
+
     /**
      * Starts a transaction by suspending auto-commit mode.
      *
@@ -749,11 +766,16 @@ class Connection implements DriverConnection
     {
         $this->connect();
 
-        if ($this->_transactionNestingLevel == 0) {
+        ++$this->_transactionNestingLevel;
+
+        if ($this->_transactionNestingLevel == 1) {
             $this->_conn->beginTransaction();
+        } else {
+            $savepointName = $this->_getNestedTransactionSavePointName($this->_transactionNestingLevel);
+            if ($savepointName) {
+                $this->createSavePoint($savepointName);
+            }
         }
-
-        ++$this->_transactionNestingLevel;
     }
 
     /**
@@ -776,6 +798,11 @@ class Connection implements DriverConnection
 
         if ($this->_transactionNestingLevel == 1) {
             $this->_conn->commit();
+        } else {
+            $savepointName = $this->_getNestedTransactionSavePointName($this->_transactionNestingLevel);
+            if ($savepointName) {
+                $this->releaseSavePoint($savepointName);
+            }
         }
 
         --$this->_transactionNestingLevel;
@@ -802,11 +829,55 @@ class Connection implements DriverConnection
             $this->_conn->rollback();
             $this->_isRollbackOnly = false;
         } else {
-            $this->_isRollbackOnly = true;
+            $savepointName = $this->_getNestedTransactionSavePointName($this->_transactionNestingLevel);
+            if (!$this->_isRollbackOnly && $savepointName) {
+                $this->rollbackSavePoint($savepointName);
+            } else {
+                $this->_isRollbackOnly = true;
+            }
             --$this->_transactionNestingLevel;
         }
     }
 
+    /**
+     * createSavepoint
+     * creates a new savepoint
+     *
+     * @param string $savepoint     name of a savepoint to set
+     * @return void
+     */
+    public function createSavePoint($savepoint)
+    {
+        //TODO check if save points are supported? if so where?
+        return $this->_conn->exec($this->_platform->createSavePoint($savepoint));
+    }
+
+    /**
+     * releaseSavePoint
+     * releases given savepoint
+     *
+     * @param string $savepoint     name of a savepoint to release
+     * @return void
+     */
+    public function releaseSavePoint($savepoint)
+    {
+        //TODO check if save points are supported? if so where?
+        return $this->_conn->exec($this->_platform->releaseSavePoint($savepoint));
+    }
+
+    /**
+     * rollbackSavePoint
+     * releases given savepoint
+     *
+     * @param string $savepoint     name of a savepoint to rollback to
+     * @return void
+     */
+    public function rollbackSavePoint($savepoint)
+    {
+        //TODO check if save points are supported? if so where?
+        return $this->_conn->exec($this->_platform->rollbackSavePoint($savepoint));
+    }
+
     /**
      * Gets the wrapped driver connection.
      *

lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php

@@ -92,4 +92,46 @@ class Driver implements \Doctrine\DBAL\Driver
         $params = $conn->getParams();
         return $params['dbname'];
     }
+
+    /**
+     * createSavepoint
+     * creates a new savepoint
+     *
+     * @param string $savepoint     name of a savepoint to set
+     * @return void
+     */
+    protected function createSavePoint($savepoint)
+    {
+        $query = 'SAVEPOINT ' . $savepoint;
+
+        return $this->conn->execute($query);
+    }
+
+    /**
+     * releaseSavePoint
+     * releases given savepoint
+     *
+     * @param string $savepoint     name of a savepoint to release
+     * @return void
+     */
+    protected function releaseSavePoint($savepoint)
+    {
+        $query = 'RELEASE SAVEPOINT ' . $savepoint;
+
+        return $this->conn->execute($query);
+    }
+
+    /**
+     * rollbackSavePoint
+     * releases given savepoint
+     *
+     * @param string $savepoint     name of a savepoint to rollback to
+     * @return void
+     */
+    protected function rollbackSavePoint($savepoint)
+    {
+        $query = 'ROLLBACK TO SAVEPOINT ' . $savepoint;
+
+        return $this->conn->execute($query);
+    }
 }
\ No newline at end of file

lib/Doctrine/DBAL/Platforms/AbstractPlatform.php

@@ -1986,4 +1986,37 @@ abstract class AbstractPlatform
     {
         return 'SELECT 1';
     }
+
+    /**
+     * Generate SQL to create a new savepoint
+     *
+     * @param string $savepoint
+     * @return string
+     */
+    public function createSavePoint($savepoint)
+    {
+        return 'SAVEPOINT ' . $savepoint;
+    }
+
+    /**
+     * Generate SQL to release a savepoint
+     *
+     * @param string $savepoint
+     * @return string
+     */
+    public function releaseSavePoint($savepoint)
+    {
+        return 'RELEASE SAVEPOINT ' . $savepoint;
+    }
+
+    /**
+     * Generate SQL to rollback a savepoint
+     *
+     * @param string $savepoint
+     * @return string
+     */
+    public function rollbackSavePoint($savepoint)
+    {
+        return 'ROLLBACK TO SAVEPOINT ' . $savepoint;
+    }
 }
\ No newline at end of file

lib/Doctrine/DBAL/Platforms/MySqlPlatform.php

@@ -267,7 +267,7 @@ class MySqlPlatform extends AbstractPlatform
      */
     public function supportsSavepoints()
     {
-        return false;
+        return true;
     }
 
     public function getShowDatabasesSQL()

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

@@ -43,10 +43,14 @@ class ConnectionTest extends \Doctrine\Tests\DbalFunctionalTestCase
                 $this->assertEquals(1, $this->_conn->getTransactionNestingLevel());
                 //no rethrow                
             }
-            $this->assertTrue($this->_conn->isRollbackOnly());
-              
-            $this->_conn->commit(); // should throw exception
-            $this->fail('Transaction commit after failed nested transaction should fail.');
+            if ($this->_conn->getDatabasePlatform()->supportsSavepoints()) {
+                $this->assertFalse($this->_conn->isRollbackOnly());
+            } else {
+                $this->assertTrue($this->_conn->isRollbackOnly());
+
+                $this->_conn->commit(); // should throw exception
+                $this->fail('Transaction commit after failed nested transaction should fail.');
+            }
         } catch (ConnectionException $e) {
             $this->assertEquals(1, $this->_conn->getTransactionNestingLevel());
             $this->_conn->rollback();

tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php

@@ -125,9 +125,9 @@ class MySqlPlatformTest extends AbstractPlatformTestCase
         $this->assertTrue($this->_platform->supportsIdentityColumns());
     }
 
-    public function testDoesNotSupportSavePoints()
+    public function testDoesSupportSavePoints()
     {
-        $this->assertFalse($this->_platform->supportsSavepoints());   
+        $this->assertTrue($this->_platform->supportsSavepoints());   
     }
 
     public function getGenerateIndexSql()