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1   /**
2    * This file Copyright (c) 2015-2016 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.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.PathNotFoundException;
45  import javax.jcr.Property;
46  import javax.jcr.RepositoryException;
47  
48  
49  /**
50   * Superclass for {@link javax.jcr.Node}-based {@link CachingStrategy}/ies.
51   *
52   * @param <P> type of ParameterProvider's parameter
53   */
54  public abstract class AbstractNodeBasedCachingStrategy<P> implements CachingStrategy<P> {
55  
56      @Override
57      public String getCachePath(ImageGenerator<ParameterProvider<P>> generator, ParameterProvider<P> parameterProvider) {
58          final P param = parameterProvider.getParameter();
59          return "/" + generator.getName() + "/" + getWorkspaceName(param) + getPathOf(param);
60      }
61  
62      /**
63       * @deprecated since 3.3 - use {@link #shouldRegenerate(Property, ParameterProvider)} instead.
64       */
65      @Deprecated
66      public boolean shouldRegenerate(NodeData cachedBinary, ParameterProvider<P> parameterProvider) {
67          try {
68              return shouldRegenerate(cachedBinary.getJCRProperty(), parameterProvider);
69          } catch (PathNotFoundException e) {
70              throw new IllegalStateException("Unable to obtain JCR Property from NodeData " + cachedBinary, e);
71          }
72      }
73  
74      /**
75       * The default implementation simply delegates this decision to ParameterProvider.
76       * @return true if the image should be regenerated.
77       */
78      @Override
79      public boolean shouldRegenerate(Property cachedBinary, ParameterProvider<P> parameterProvider) {
80          try {
81              // this is assuming the cached node's metadata was updated, not just the binary
82              final Calendar cacheLastMod = NodeTypes.LastModified.getLastModified(cachedBinary.getParent());
83  
84              // this is assuming our parameter's mgnl:metaData was updated when updating any of its properties/binaries
85              final Node node = getContent(parameterProvider.getParameter());
86              final Calendar srcLastMod = NodeTypes.LastModified.getLastModified(node);
87  
88              //we should always check for the other one anyway since getModificationDate() _can_ return null
89              if (srcLastMod == null ) {
90                  // no srcLastMod update, means likely also no source at all ...
91                  return false;
92              } else if (cacheLastMod == null) {
93                  // no cacheLstMod update, means that the copy is stale or not created properly
94                  return true;
95              } else {
96                  return cacheLastMod.before(srcLastMod);
97              }
98          } catch (RepositoryException e) {
99              throw new RuntimeException(e);
100         }
101     }
102 
103     abstract protected String getWorkspaceName(P param);
104 
105     abstract protected Node getContent(P param);
106 
107     abstract protected String getPathOf(P param);
108 }