001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2009 Sun Microsystems, Inc.
015 * Portions copyright 2014-2015 ForgeRock AS.
016 */
017package org.forgerock.opendj.ldap.spi;
018
019import java.util.Collection;
020
021import org.forgerock.opendj.ldap.ByteSequence;
022import org.forgerock.opendj.ldap.ByteString;
023import org.forgerock.opendj.ldap.DecodeException;
024import org.forgerock.opendj.ldap.schema.Schema;
025
026/**
027 * This class is registered with a Backend and it provides callbacks
028 * for indexing attribute values. An index implementation will use
029 * this interface to create the keys for an attribute value.
030 */
031public interface Indexer {
032
033    /**
034     * Returns an index identifier associated with this indexer. An identifier
035     * should be selected based on the matching rule type. A unique identifier
036     * will map to a unique index database in the backend implementation. If
037     * multiple matching rules need to share the index database, the
038     * corresponding indexers should always use the same identifier.
039     *
040     * @return index ID A String containing the ID associated with this indexer.
041     */
042    String getIndexID();
043
044    /**
045     * Generates the set of index keys for an attribute.
046     *
047     * @param schema
048     *          The schema in which the associated matching rule is defined.
049     * @param value
050     *          The attribute value for which keys are required.
051     * @param keys
052     *          A collection where to add the created keys.
053     * @throws DecodeException if an error occurs while normalizing the value
054     */
055    void createKeys(Schema schema, ByteSequence value, Collection<ByteString> keys) throws DecodeException;
056
057    /**
058     * Returns a human readable representation of the key.
059     * Does a best effort conversion from an index key to a string that can be printed, as
060     * used by the diagnostic tools, which are the only users of the method.
061     * It is not necessary for the resulting string to exactly match the value it was
062     * generated from.
063     *
064     * @param key the byte string for the index key.
065     * @return a human readable representation of the key
066     */
067    String keyToHumanReadableString(ByteSequence key);
068}