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/**
* Return true the storage supports transactions.
*
* @return {@code true} if the storage supports transactions, {@code false} otherwise
*/
@Evolving
default boolean transactional() {
   return false;
}

/**
 * Flush any cached data
 *
 */
@Deprecated
default void flush() {}

/**
  * Flush and commit any cached data
  * <p>
  * For transactional state store commit applies all changes atomically. In other words, either the
  * entire commit will be successful or none of the changes will be applied.
  * <p>
  * For non-transactional state store this method flushes cached data.
  *
  * @param changelogOffset the offset of the changelog topic this commit corresponds to. The
  *                        offset can be null if the state store does not have a changelog
  *                        (e.g. a global store).
  * @code null}
  */
@Evolving
default void commit(final Long changelogOffset) {
    if (transactional()) {
      throw new UnsupportedOperationException("Transactional state store must implement StateStore#commit");
    } else {
      flush();
    }
}      

/**
 * Recovers the state store after crash failure.
 * <p>
 * The state store recovers by discarding any writes that are not committed to the changelog
 * and rolling to the state that corresponds to {@code changelogOffset} or greater offset of
 * the changelog topic.
 *
 * @param changelogOffset the checkpointed changelog offset.
 * @return {@code true} if the state store recovered, {@code false} otherwise.
 */
@Evolving
default boolean recover(final long changelogOffset) {
    if (transactional()) {
        throw new UnsupportedOperationException("Transactional state store must implement StateStore#recover");
    }
    return false;
}