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.core.partition.impl.btree;
021    
022    
023    import java.io.Serializable;
024    
025    import org.apache.directory.shared.ldap.schema.comparators.SerializableComparator;
026    
027    
028    /**
029     * Used to compare the sorting order of binary data.
030     * 
031     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
032     * @version $Rev: 917231 $
033     */
034    public interface TupleComparator<K, V> extends Serializable
035    {
036        /**
037         * Gets the comparator used to compare keys.  May be null in which
038         * case the compareKey method will throw an UnsupportedOperationException.
039         *
040         * @return the comparator for comparing keys.
041         */
042        SerializableComparator<K> getKeyComparator();
043    
044    
045        /**
046         * Gets the binary comparator used to compare valuess.  May be null in which
047         * case the compareValue method will throw an UnsupportedOperationException.
048         *
049         * @return the binary comparator for comparing values.
050         */
051        SerializableComparator<V> getValueComparator();
052    
053    
054        /**
055         * Compares key Object to determine their sorting order returning a
056         * value = to, < or > than 0.
057         *
058         * @param key1 the first key to compare
059         * @param key2 the other key to compare to the first
060         * @return 0 if both are equal, a negative value less than 0 if the first
061         * is less than the second, or a postive value if the first is greater than
062         * the second byte array.
063         */
064        int compareKey( K key1, K key2 );
065    
066    
067        /**
068         * Comparse value Objects to determine their sorting order returning a
069         * value = to, < or > than 0.
070         *
071         * @param value1 the first value to compare
072         * @param value2 the other value to compare to the first
073         * @return 0 if both are equal, a negative value less than 0 if the first
074         * is less than the second, or a postive value if the first is greater than
075         * the second Object.
076         */
077        int compareValue( V value1, V value2 );
078    }