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.mavibot.btree; 21 22 23 /** 24 * A In-Memory Value holder. The value is always present in memory. 25 * 26 * @param <K> The type of the BTree key 27 * @param <V> The type of the BTree value 28 * 29 * @author <a href="mailto:labs@labs.apache.org">Mavibot labs Project</a> 30 */ 31 public class MemoryHolder<K, V> implements ElementHolder<V, K, V> 32 { 33 /** The BTree */ 34 private BTree<K, V> btree; 35 36 /** The reference to the Value instance, or null if it's not present */ 37 private V value; 38 39 40 /** 41 * Create a new holder storing an offset and a SoftReference containing the value. 42 * 43 * @param offset The offset in disk for this value 44 * @param value The value to store into a SoftReference 45 */ 46 public MemoryHolder( BTree<K, V> btree, V value ) 47 { 48 this.btree = btree; 49 this.value = value; 50 } 51 52 53 /** 54 * {@inheritDoc} 55 */ 56 @Override 57 public V getValue( BTree<K, V> btree ) 58 { 59 return value; 60 } 61 62 63 /** 64 * @see Object#toString() 65 */ 66 public String toString() 67 { 68 StringBuilder sb = new StringBuilder(); 69 70 sb.append( "'" ); 71 72 V value = getValue( btree ); 73 74 sb.append( value ); 75 76 sb.append( "'" ); 77 78 return sb.toString(); 79 } 80 }