/**
   * Rolls back hibernate session.
   *
   * @param ses Hibernate session.
   * @param tx Cache ongoing transaction.
   */
  private void rollback(SharedSessionContract ses, GridCacheTx tx) {
    // Rollback only if there is no cache transaction,
    // otherwise txEnd() will do all required work.
    if (tx == null) {
      Transaction hTx = ses.getTransaction();

      if (hTx != null && hTx.isActive()) hTx.rollback();
    }
  }
  /**
   * Ends hibernate session.
   *
   * @param ses Hibernate session.
   * @param tx Cache ongoing transaction.
   */
  private void end(Session ses, GridCacheTx tx) {
    // Commit only if there is no cache transaction,
    // otherwise txEnd() will do all required work.
    if (tx == null) {
      Transaction hTx = ses.getTransaction();

      if (hTx != null && hTx.isActive()) hTx.commit();

      ses.close();
    }
  }
  /** {@inheritDoc} */
  @Override
  public void onSessionEnd(CacheStoreSession ses, boolean commit) {
    Session hibSes = ses.attach(null);

    if (hibSes != null) {
      try {
        Transaction tx = hibSes.getTransaction();

        if (commit) {
          hibSes.flush();

          if (tx.isActive()) tx.commit();
        } else if (tx.isActive()) tx.rollback();
      } catch (HibernateException e) {
        throw new CacheWriterException(
            "Failed to end store session [tx=" + ses.transaction() + ']', e);
      } finally {
        hibSes.close();
      }
    }
  }