1 | /* |
2 | * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0, |
3 | * and the EPL 1.0 (http://h2database.com/html/license.html). |
4 | * Initial Developer: H2 Group |
5 | */ |
6 | package org.h2.util; |
7 | |
8 | import java.util.LinkedHashMap; |
9 | import java.util.Map; |
10 | |
11 | /** |
12 | * This class implements a small LRU object cache. |
13 | * |
14 | * @param <K> the key |
15 | * @param <V> the value |
16 | */ |
17 | public class SmallLRUCache<K, V> extends LinkedHashMap<K, V> { |
18 | |
19 | private static final long serialVersionUID = 1L; |
20 | private int size; |
21 | |
22 | private SmallLRUCache(int size) { |
23 | super(size, (float) 0.75, true); |
24 | this.size = size; |
25 | } |
26 | |
27 | /** |
28 | * Create a new object with all elements of the given collection. |
29 | * |
30 | * @param <K> the key type |
31 | * @param <V> the value type |
32 | * @param size the number of elements |
33 | * @return the object |
34 | */ |
35 | public static <K, V> SmallLRUCache<K, V> newInstance(int size) { |
36 | return new SmallLRUCache<K, V>(size); |
37 | } |
38 | |
39 | public void setMaxSize(int size) { |
40 | this.size = size; |
41 | } |
42 | |
43 | @Override |
44 | protected boolean removeEldestEntry(Map.Entry<K, V> eldest) { |
45 | return size() > size; |
46 | } |
47 | |
48 | } |