1 /**
2 * This file Copyright (c) 2016 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.config.registry.decoration;
35
36 import info.magnolia.config.registry.DefinitionProvider;
37
38 import com.google.common.base.Objects;
39
40
41 /**
42 * Caches the decoration result - won't do decoration again if incoming argument is the same.
43 *
44 * @param <T> the decorated definition type
45 */
46 public class CachingDefinitionDecorator<T> implements DefinitionDecorator<T> {
47
48 private DefinitionDecorator<T> delegate;
49
50 private DefinitionProvider<T> decorationResult;
51
52 private DefinitionProvider<T> decoratedDefinitionProvider;
53
54 public CachingDefinitionDecorator(DefinitionDecorator<T> delegate) {
55 this.delegate = delegate;
56 }
57
58 @Override
59 public DefinitionDecoratorMetadata metadata() {
60 return delegate.metadata();
61 }
62
63 @Override
64 public boolean appliesTo(DefinitionProvider<T> definitionProvider) {
65 return delegate.appliesTo(definitionProvider);
66 }
67
68 @Override
69 public DefinitionProvider<T> decorate(DefinitionProvider<T> definitionProvider) {
70 if (!Objects.equal(definitionProvider, decoratedDefinitionProvider)) {
71 this.decoratedDefinitionProvider = definitionProvider;
72 this.decorationResult = delegate.decorate(decoratedDefinitionProvider);
73 }
74
75 return decorationResult;
76 }
77
78 @Override
79 public String toString() {
80 return this.delegate.toString();
81 }
82
83 @Override
84 public boolean equals(Object o) {
85 if (this == o) return true;
86
87 if (!(o instanceof DefinitionDecorator)) {
88 return false;
89 }
90
91 DefinitionDecorator other = (DefinitionDecorator) o;
92 if (other instanceof CachingDefinitionDecorator) {
93 other = ((CachingDefinitionDecorator)other).delegate;
94 }
95
96 return Objects.equal(this.delegate, other);
97 }
98
99 @Override
100 public int hashCode() {
101 return Objects.hashCode(delegate);
102 }
103 }