1 /**
2 * This file Copyright (c) 2015 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.imaging.caching;
35
36 import info.magnolia.cms.core.NodeData;
37 import info.magnolia.imaging.ImageGenerator;
38 import info.magnolia.imaging.ParameterProvider;
39 import info.magnolia.jcr.util.NodeTypes;
40
41 import java.util.Calendar;
42
43 import javax.jcr.Node;
44 import javax.jcr.RepositoryException;
45
46
47 /**
48 * Superclass for {@link javax.jcr.Node}-based {@link CachingStrategy}/ies.
49 *
50 * @param <P> type of ParameterProvider's parameter
51 */
52 public abstract class AbstractNodeBasedCachingStrategy<P> implements CachingStrategy<P> {
53
54 @Override
55 public String getCachePath(ImageGenerator<ParameterProvider<P>> generator, ParameterProvider<P> parameterProvider) {
56 final P param = parameterProvider.getParameter();
57 return "/" + generator.getName() + "/" + getWorkspaceName(param) + getPathOf(param);
58 }
59
60 /**
61 * The default implementation simply delegates this decision to ParameterProvider.
62 * @return true if the image should be regenerated.
63 */
64 @Override
65 public boolean shouldRegenerate(NodeData cachedBinary, ParameterProvider<P> parameterProvider) {
66 try {
67 // this is assuming the cached node's metadata was updated, not just the binary
68 final Calendar cacheLastMod = cachedBinary.getParent().getMetaData().getModificationDate();
69
70 // this is assuming our parameter's mgnl:metaData was updated when updating any of its properties/binaries
71 final Node node = getContent(parameterProvider.getParameter());
72 final Calendar srcLastMod = NodeTypes.LastModified.getLastModified(node);
73
74 //we should always check for the other one anyway since getModificationDate() _can_ return null
75 if (srcLastMod == null ) {
76 // no srcLastMod update, means likely also no source at all ...
77 return false;
78 } else if (cacheLastMod == null) {
79 // no cacheLstMod update, means that the copy is stale or not created properly
80 return true;
81 } else {
82 return cacheLastMod.before(srcLastMod);
83 }
84 } catch (RepositoryException e) {
85 throw new RuntimeException(e);
86 }
87 }
88
89 abstract protected String getWorkspaceName(P param);
90
91 abstract protected Node getContent(P param);
92
93 abstract protected String getPathOf(P param);
94 }