Transaction::__construct

public Transaction::__construct(Connection $connection, $name = NULL)

public function __construct(Connection $connection, $name = NULL) {
  $this->connection = $connection;
  // If there is no transaction depth, then no transaction has started. Name
  // the transaction 'drupal_transaction'.
  if (!$depth = $connection->transactionDepth()) {
    $this->name = 'drupal_transaction';
  }
  // Within transactions, savepoints are used. Each savepoint requires a
  // name. So if no name is present we need to create one.
  elseif (!$name) {
    $this->name = 'savepoint_' . $depth;
  }
  else {
    $this->name = $name;
  }
  $this->connection->pushTransaction($this->name);
}