001/*
002 * CDDL HEADER START
003 *
004 * The contents of this file are subject to the terms of the
005 * Common Development and Distribution License, Version 1.0 only
006 * (the "License").  You may not use this file except in compliance
007 * with the License.
008 *
009 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
010 * or http://forgerock.org/license/CDDLv1.0.html.
011 * See the License for the specific language governing permissions
012 * and limitations under the License.
013 *
014 * When distributing Covered Code, include this CDDL HEADER in each
015 * file and include the License file at legal-notices/CDDLv1_0.txt.
016 * If applicable, add the following below this CDDL HEADER, with the
017 * fields enclosed by brackets "[]" replaced with your own identifying
018 * information:
019 *      Portions Copyright [yyyy] [name of copyright owner]
020 *
021 * CDDL HEADER END
022 *
023 *
024 *      Copyright 2014-2015 ForgeRock AS
025 */
026package org.opends.server.backends.pluggable.spi;
027
028/**
029 * Function performing a read operation.
030 *
031 * @param <T>
032 *          type of the value that is read and returned by this read operation
033 */
034// @FunctionalInterface
035public interface ReadOperation<T>
036{
037  /**
038   * Executes a read operation, and returns the read value.
039   *
040   * @param txn
041   *          the read transaction where to execute the read operation
042   * @return the read value
043   * @throws Exception
044   *           if a problem occurs with the underlying storage engine
045   */
046  T run(ReadableTransaction txn) throws Exception;
047}