Transaction.php

<?php

namespace Drupal\Core\Database;


/**
 * A wrapper class for creating and managing database transactions.
 *
 * Not all databases or database configurations support transactions. For
 * example, MySQL MyISAM tables do not. It is also easy to begin a transaction
 * and then forget to commit it, which can lead to connection errors when
 * another transaction is started.
 *
 * This class acts as a wrapper for transactions. To begin a transaction,
 * simply instantiate it. When the object goes out of scope and is destroyed
 * it will automatically commit. It also will check to see if the specified
 * connection supports transactions. If not, it will simply skip any transaction
 * commands, allowing user-space code to proceed normally. The only difference
 * is that rollbacks won't actually do anything.
 *
 * In the vast majority of cases, you should not instantiate this class
 * directly. Instead, call ->startTransaction(), from the appropriate connection
 * object.
 */
class Transaction {
    public function __construct(Connection $connection, string $name, string $id) {
        // Transactions rely on objects being destroyed in order to be committed.
        // PHP makes no guarantee about the order in which objects are destroyed so
        // ensure all transactions are committed on shutdown.
        Database::commitAllOnShutdown();
    }
    public function __destruct() {
        $this->connection
            ->transactionManager()
            ->unpile($this->name, $this->id);
    }
    
    /**
     * Retrieves the name of the transaction or savepoint.
     */
    public function name() {
        return $this->name;
    }
    
    /**
     * Rolls back the current transaction.
     *
     * This is just a wrapper method to rollback whatever transaction stack we are
     * currently in, which is managed by the connection object itself. Note that
     * logging needs to happen after a transaction has been rolled back or the log
     * messages will be rolled back too.
     *
     * @see \Drupal\Core\Database\Connection::rollBack()
     */
    public function rollBack() {
        $this->connection
            ->transactionManager()
            ->rollback($this->name, $this->id);
    }

}