Merge branch '2.2-nested-transaction' into 2.2

lib/Cake/Model/Datasource/Database/Mysql.php

@@ -77,17 +77,6 @@ class Mysql extends DboSource {
  */
 	protected $_useAlias = true;
 
-/**
- * Index of basic SQL commands
- *
- * @var array
- */
-	protected $_commands = array(
-		'begin'    => 'START TRANSACTION',
-		'commit'   => 'COMMIT',
-		'rollback' => 'ROLLBACK'
-	);
-
 /**
  * List of engine specific additional field parameters used on table creating
  *
@@ -262,15 +251,6 @@ public function getEncoding() {
 		return $this->_execute('SHOW VARIABLES LIKE ?', array('character_set_client'))->fetchObject()->Value;
 	}
 
-/**
- * Gets the version string of the database server
- *
- * @return string The database encoding
- */
-	public function getVersion() {
-		return $this->_connection->getAttribute(PDO::ATTR_SERVER_VERSION);
-	}
-
 /**
  * Query charset by collation
  *
@@ -696,4 +676,13 @@ public function getSchemaName() {
 		return $this->config['database'];
 	}
 
+/**
+ * Check if the server support nested transactions
+ *
+ * @return boolean
+ */
+	public function supportNestedTransaction() {
+		return $this->nestedTransaction && version_compare($this->getVersion(), '4.1', '>=');
+	}
+
 }

lib/Cake/Model/Datasource/Database/Postgres.php

@@ -33,17 +33,6 @@ class Postgres extends DboSource {
  */
 	public $description = "PostgreSQL DBO Driver";
 
-/**
- * Index of basic SQL commands
- *
- * @var array
- */
-	protected $_commands = array(
-		'begin'    => 'BEGIN',
-		'commit'   => 'COMMIT',
-		'rollback' => 'ROLLBACK'
-	);
-
 /**
  * Base driver configuration settings.  Merged with user settings.
  *
@@ -906,4 +895,13 @@ public function getSchemaName() {
 		return $this->config['schema'];
 	}
 
+/**
+ * Check if the server support nested transactions
+ *
+ * @return boolean
+ */
+	public function supportNestedTransaction() {
+		return $this->nestedTransaction && version_compare($this->getVersion(), '8.0', '>=');
+	}
+
 }

lib/Cake/Model/Datasource/Database/Sqlite.php

@@ -559,4 +559,13 @@ public function getSchemaName() {
 		return "main"; // Sqlite Datasource does not support multidb
 	}
 
+/**
+ * Check if the server support nested transactions
+ *
+ * @return boolean
+ */
+	public function supportNestedTransaction() {
+		return $this->nestedTransaction && version_compare($this->getVersion(), '3.6.8', '>=');
+	}
+
 }

lib/Cake/Model/Datasource/Database/Sqlserver.php

@@ -98,31 +98,12 @@ class Sqlserver extends DboSource {
 		'boolean'	=> array('name' => 'bit')
 	);
 
-/**
- * Index of basic SQL commands
- *
- * @var array
- */
-	protected $_commands = array(
-		'begin'    => 'BEGIN TRANSACTION',
-		'commit'   => 'COMMIT',
-		'rollback' => 'ROLLBACK'
-	);
-
 /**
  * Magic column name used to provide pagination support for SQLServer 2008
  * which lacks proper limit/offset support.
  */
 	const ROW_COUNTER = '_cake_page_rownum_';
 
-/**
- * The version of SQLServer being used.  If greater than 11
- * Normal limit offset statements will be used
- *
- * @var string
- */
-	protected $_version;
-
 /**
  * Connects to the database using options in the given configuration array.
  *
@@ -151,7 +132,6 @@ public function connect() {
 			throw new MissingConnectionException(array('class' => $e->getMessage()));
 		}
 
-		$this->_version = $this->_connection->getAttribute(PDO::ATTR_SERVER_VERSION);
 		return $this->connected;
 	}
 
@@ -515,7 +495,7 @@ public function renderStatement($type, $data) {
 				}
 
 				// For older versions use the subquery version of pagination.
-				if (version_compare($this->_version, '11', '<') && preg_match('/FETCH\sFIRST\s+([0-9]+)/i', $limit, $offset)) {
+				if (version_compare($this->getVersion(), '11', '<') && preg_match('/FETCH\sFIRST\s+([0-9]+)/i', $limit, $offset)) {
 					preg_match('/OFFSET\s*(\d+)\s*.*?(\d+)\s*ROWS/', $limit, $limitOffset);
 
 					$limit = 'TOP ' . intval($limitOffset[2]);

lib/Cake/Model/Datasource/DboSource.php

@@ -69,6 +69,15 @@ class DboSource extends DataSource {
  */
 	public $cacheMethods = true;
 
+/**
+ * Flag to support nested transactions. If it is set to false, you will be able to use
+ * the transaction methods (begin/commit/rollback), but just the global transaction will
+ * be executed.
+ *
+ * @var boolean
+ */
+	public $nestedTransaction = true;
+
 /**
  * Print full query debug info?
  *
@@ -183,17 +192,6 @@ class DboSource extends DataSource {
  */
 	protected $_transactionNesting = 0;
 
-/**
- * Index of basic SQL commands
- *
- * @var array
- */
-	protected $_commands = array(
-		'begin' => 'BEGIN',
-		'commit' => 'COMMIT',
-		'rollback' => 'ROLLBACK'
-	);
-
 /**
  * Default fields that are used by the DBO
  *
@@ -294,12 +292,21 @@ public function disconnect() {
 /**
  * Get the underlying connection object.
  *
- * @return PDOConnection
+ * @return PDO
  */
 	public function getConnection() {
 		return $this->_connection;
 	}
 
+/**
+ * Gets the version string of the database server
+ *
+ * @return string The database version
+ */
+	public function getVersion() {
+		return $this->_connection->getAttribute(PDO::ATTR_SERVER_VERSION);
+	}
+
 /**
  * Returns a quoted and escaped string of $data for use in an SQL statement.
  *
@@ -2019,6 +2026,15 @@ public function truncate($table) {
 		return $this->execute('TRUNCATE TABLE ' . $this->fullTableName($table));
 	}
 
+/**
+ * Check if the server support nested transactions
+ *
+ * @return boolean
+ */
+	public function supportNestedTransaction() {
+		return false;
+	}
+
 /**
  * Begin a transaction
  *
@@ -2027,15 +2043,33 @@ public function truncate($table) {
  * or a transaction has not started).
  */
 	public function begin() {
-		if ($this->_transactionStarted || $this->_connection->beginTransaction()) {
-			if ($this->fullDebug && empty($this->_transactionNesting)) {
-				$this->logQuery('BEGIN');
+		if ($this->_transactionStarted) {
+			if ($this->supportNestedTransaction()) {
+				return $this->_beginNested();
 			}
-			$this->_transactionStarted = true;
 			$this->_transactionNesting++;
-			return true;
+			return $this->_transactionStarted;
 		}
-		return false;
+
+		$this->_transactionNesting = 0;
+		if ($this->fullDebug) {
+			$this->logQuery('BEGIN');
+		}
+		return $this->_transactionStarted = $this->_connection->beginTransaction();
+	}
+
+/**
+ * Begin a nested transaction
+ *
+ * @return boolean
+ */
+	protected function _beginNested() {
+		$query = 'SAVEPOINT LEVEL' . ++$this->_transactionNesting;
+		if ($this->fullDebug) {
+			$this->logQuery($query);
+		}
+		$this->_connection->exec($query);
+		return true;
 	}
 
 /**
@@ -2046,19 +2080,38 @@ public function begin() {
  * or a transaction has not started).
  */
 	public function commit() {
-		if ($this->_transactionStarted) {
-			$this->_transactionNesting--;
-			if ($this->_transactionNesting <= 0) {
-				$this->_transactionStarted = false;
-				$this->_transactionNesting = 0;
-				if ($this->fullDebug) {
-					$this->logQuery('COMMIT');
-				}
-				return $this->_connection->commit();
+		if (!$this->_transactionStarted) {
+			return false;
+		}
+
+		if ($this->_transactionNesting === 0) {
+			if ($this->fullDebug) {
+				$this->logQuery('COMMIT');
 			}
-			return true;
+			$this->_transactionStarted = false;
+			return $this->_connection->commit();
 		}
-		return false;
+
+		if ($this->supportNestedTransaction()) {
+			return $this->_commitNested();
+		}
+
+		$this->_transactionNesting--;
+		return true;
+	}
+
+/**
+ * Commit a nested transaction
+ *
+ * @return boolean
+ */
+	protected function _commitNested() {
+		$query = 'RELEASE SAVEPOINT LEVEL' . $this->_transactionNesting--;
+		if ($this->fullDebug) {
+			$this->logQuery($query);
+		}
+		$this->_connection->exec($query);
+		return true;
 	}
 
 /**
@@ -2069,15 +2122,38 @@ public function commit() {
  * or a transaction has not started).
  */
 	public function rollback() {
-		if ($this->_transactionStarted && $this->_connection->rollBack()) {
+		if (!$this->_transactionStarted) {
+			return false;
+		}
+
+		if ($this->_transactionNesting === 0) {
 			if ($this->fullDebug) {
 				$this->logQuery('ROLLBACK');
 			}
 			$this->_transactionStarted = false;
-			$this->_transactionNesting = 0;
-			return true;
+			return $this->_connection->rollBack();
 		}
-		return false;
+
+		if ($this->supportNestedTransaction()) {
+			return $this->_rollbackNested();
+		}
+
+		$this->_transactionNesting--;
+		return true;
+	}
+
+/**
+ * Rollback a nested transaction
+ *
+ * @return boolean
+ */
+	protected function _rollbackNested() {
+		$query = 'ROLLBACK TO SAVEPOINT LEVEL' . $this->_transactionNesting--;
+		if ($this->fullDebug) {
+			$this->logQuery($query);
+		}
+		$this->_connection->exec($query);
+		return true;
 	}
 
 /**

lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php

@@ -45,7 +45,7 @@ class MysqlTest extends CakeTestCase {
 	public $fixtures = array(
 		'core.apple', 'core.article', 'core.articles_tag', 'core.attachment', 'core.comment',
 		'core.sample', 'core.tag', 'core.user', 'core.post', 'core.author', 'core.data_test',
-		'core.binary_test'
+		'core.binary_test', 'app.address'
 	);
 
 /**
@@ -3579,4 +3579,38 @@ public function testTruncateStatements() {
 			->with("TRUNCATE TABLE `$schema`.`tbl_articles`");
 		$this->Dbo->truncate('articles');
 	}
+
+/**
+ * Test nested transaction
+ *
+ * @return void
+ */
+	public function testNestedTransaction() {
+		$this->skipIf($this->Dbo->supportNestedTransaction() === false, 'The MySQL server do not support nested transaction');
+
+		$this->loadFixtures('Address');
+		$model = ClassRegistry::init('Address');
+		$model->hasOne = $model->hasMany = $model->belongsTo = $model->hasAndBelongsToMany = array();
+		$model->cacheQueries = false;
+		$this->Dbo->cacheMethods = false;
+
+		$this->assertTrue($this->Dbo->begin());
+		$this->assertNotEmpty($model->read(null, 1));
+
+		$this->assertTrue($this->Dbo->begin());
+		$this->assertTrue($model->delete(1));
+		$this->assertEmpty($model->read(null, 1));
+		$this->assertTrue($this->Dbo->rollback());
+		$this->assertNotEmpty($model->read(null, 1));
+
+		$this->assertTrue($this->Dbo->begin());
+		$this->assertTrue($model->delete(1));
+		$this->assertEmpty($model->read(null, 1));
+		$this->assertTrue($this->Dbo->commit());
+		$this->assertEmpty($model->read(null, 1));
+
+		$this->assertTrue($this->Dbo->rollback());
+		$this->assertNotEmpty($model->read(null, 1));
+	}
+
 }