1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.directory.server.core.partition.impl.btree; 21 22 23 import org.apache.directory.api.ldap.model.schema.comparators.SerializableComparator; 24 25 26 /** 27 * TupleComparator for index records. 28 * 29 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 30 */ 31 public class ForwardIndexComparator<K> implements TupleComparator<K, Long> 32 { 33 private static final long serialVersionUID = 3257283621751633459L; 34 35 /** The key comparison to use */ 36 private final SerializableComparator<K> keyComparator; 37 38 39 /** 40 * Creates an IndexComparator. 41 * 42 * @param keyComparator the table comparator to use for keys 43 */ 44 public ForwardIndexComparator( SerializableComparator<K> keyComparator ) 45 { 46 this.keyComparator = keyComparator; 47 } 48 49 50 /** 51 * Gets the comparator used to compare keys. 52 * 53 * @return the comparator for comparing keys. 54 */ 55 public SerializableComparator<K> getKeyComparator() 56 { 57 return keyComparator; 58 } 59 60 61 /** 62 * Gets the binary comparator used to compare values which are the indices 63 * into the master table. 64 * 65 * @return the binary comparator for comparing values. 66 */ 67 public SerializableComparator<Long> getValueComparator() 68 { 69 return LongComparator.INSTANCE; 70 } 71 72 73 /** 74 * Compares key Object to determine their sorting order returning a 75 * value = to, < or > than 0. 76 * 77 * @param key1 the first key to compare 78 * @param key2 the other key to compare to the first 79 * @return 0 if both are equal, a negative value less than 0 if the first 80 * is less than the second, or a poistive value if the first is greater than 81 * the second byte array. 82 */ 83 public int compareKey( K key1, K key2 ) 84 { 85 return getKeyComparator().compare( key1, key2 ); 86 } 87 88 89 /** 90 * Comparse value Objects to determine their sorting order returning a 91 * value = to, < or > than 0. 92 * 93 * @param l1 the first Long value to compare 94 * @param l2 the other Long value to compare to the first 95 * @return 0 if both are equal, a negative value less than 0 if the first 96 * is less than the second, or a positive value if the first is greater than 97 * the second Object. 98 */ 99 public int compareValue( Long l1, Long l2 ) 100 { 101 return ( l1 < l2 ? -1 : ( l1.equals( l2 ) ? 0 : 1 ) ); 102 } 103 }