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
028import java.io.Closeable;
029
030import org.forgerock.opendj.ldap.ByteSequence;
031import org.forgerock.opendj.ldap.ByteString;
032
033/**
034 * Allows to run an import. For performance reasons, imports are run without transactions.
035 * <p>
036 * Since import is multi threaded, implementations must be thread-safe.
037 * <p>
038 *
039 * @ThreadSafe
040 */
041public interface Importer extends Closeable
042{
043  /**
044   * Clear the tree whose name is provided. Ensure that an empty tree with the given name exists. If the tree already
045   * exists, all the data it contains will be deleted. If not, an empty tree will be created.
046   *
047   * @param treeName name of the tree to clear
048   */
049  void clearTree(TreeName treeName);
050
051  /**
052   * Creates a record with the provided key and value in the tree identified by the provided name. At the end of this
053   * method, the record is visible by {@link read(TreeName, ByteSequence)} and {@link openCursor(TreeName)} methods of
054   * this instance. The record is guaranteed to be persisted only after {@link #close()}.
055   *
056   * @param treeName
057   *          the tree name
058   * @param key
059   *          the new record's key
060   * @param value
061   *          the new record's value
062   */
063  void put(TreeName treeName, ByteSequence key, ByteSequence value);
064
065  /**
066   * Reads the record's value associated to the provided key, in the tree whose name is provided.
067   *
068   * @param treeName
069   *          the tree name
070   * @param key
071   *          the record's key
072   * @return the record's value, or {@code null} if none exists
073   */
074  ByteString read(TreeName treeName, ByteSequence key);
075
076  /**
077   * Opens a cursor on the tree whose name is provided. Cursors are predictable only if there is no pending
078   * {@link put(TreeName, ByteSequence, ByteSequence)} operations. Indeed, once opened, cursors might not reflect
079   * changes.
080   *
081   * @param treeName
082   *          the tree name
083   * @return a new cursor
084   */
085  SequentialCursor<ByteString, ByteString> openCursor(TreeName treeName);
086
087  @Override
088  void close();
089}