001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.server.xdbm.search;
021    
022    
023    import org.apache.directory.shared.ldap.constants.JndiPropertyConstants;
024    import org.apache.directory.shared.ldap.entry.ServerEntry;
025    import org.apache.directory.shared.ldap.filter.ExprNode;
026    import org.apache.directory.shared.ldap.message.AliasDerefMode;
027    import org.apache.directory.shared.ldap.name.DN;
028    import org.apache.directory.server.xdbm.IndexCursor;
029    
030    import javax.naming.directory.SearchControls;
031    
032    
033    /**
034     * Given a search filter and a scope the search engine identifies valid
035     * candidate entries returning their ids.
036     * 
037     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
038     * @version $Rev: 927146 $
039     */
040    public interface SearchEngine<E, ID>
041    {
042        /**
043         * @todo put this in the right place
044         * The alias dereferencing mode key for JNDI providers 
045         */
046        String ALIASMODE_KEY = JndiPropertyConstants.JNDI_LDAP_DAP_DEREF_ALIASES;
047        /** 
048         * @todo put this in the right place
049         * The alias dereferencing mode value for JNDI providers 
050         */
051        String ALWAYS = "always";
052        /** 
053         * @todo put this in the right place
054         * The alias dereferencing mode value for JNDI providers 
055         */
056        String NEVER = "never";
057        /** 
058         * @todo put this in the right place
059         * The alias dereferencing mode value for JNDI providers 
060         */
061        String FINDING = "finding";
062        /** 
063         * @todo put this in the right place
064         * The alias dereferencing mode value for JNDI providers 
065         */
066        String SEARCHING = "searching";
067    
068    
069        /**
070         * Gets the optimizer for this DefaultSearchEngine.
071         *
072         * @return the optimizer
073         */
074        Optimizer getOptimizer();
075    
076    
077        /**
078         * Conducts a search on a database.
079         * 
080         * @param base the search base
081         * @param aliasDerefMode the alias dereferencing mode to use
082         * @param filter the search filter AST root
083         * @param searchCtls the JNDI search controls
084         * @return enumeration over SearchResults
085         * @throws Exception if the search fails
086         */
087        IndexCursor<ID, E, ID> cursor( DN base, AliasDerefMode aliasDerefMode, ExprNode filter,
088            SearchControls searchCtls ) throws Exception;
089    
090    
091        /**
092         * Builds an Evaluator for a filter expression.
093         * 
094         * @param filter the filter root AST node
095         * @return true if the filter passes the entry, false otherwise
096         * @throws Exception if something goes wrong while accessing the db
097         */
098        Evaluator<? extends ExprNode, ServerEntry, ID> evaluator( ExprNode filter ) throws Exception;
099    }