1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.utils.datastructures.cache;
16 * Caches the value provided by the back-end provider.
18 * Cached version is equal to original in hashCode/equals wise.
20 * @author Toni Kalajainen
22 public class CachedProvider<V> implements IProvider<V> {
24 public static final <V> IProvider<V> cache(IProvider<V> provider)
26 if (provider instanceof CachedProvider<?>)
28 return new CachedProvider<V>(provider);
31 IProvider<V> backendProvider;
34 CachedProvider(IProvider<V> orig)
36 this.backendProvider = orig;
40 public synchronized V get() throws ProvisionException {
42 value = backendProvider.get();
48 public int hashCode() {
49 return backendProvider.hashCode();
53 public boolean equals(Object obj) {
54 return backendProvider.equals(obj);