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1   /***
2    *  Copyright 2003-2010 Terracotta, Inc.
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License");
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License.
15   */
16  
17  package net.sf.ehcache.config.generator;
18  
19  import java.util.HashSet;
20  import java.util.List;
21  import java.util.Set;
22  import java.util.concurrent.ConcurrentHashMap;
23  import java.util.concurrent.ConcurrentMap;
24  
25  import net.sf.ehcache.config.generator.model.AbstractDepthFirstVisitor;
26  import net.sf.ehcache.config.generator.model.NodeAttribute;
27  import net.sf.ehcache.config.generator.model.NodeElement;
28  
29  public class RememberingVisitor extends AbstractDepthFirstVisitor {
30      private final Set<NodeElement> visitedElements = new HashSet<NodeElement>();
31      private final ConcurrentMap<NodeElement, Set<NodeAttribute>> visitedAttributes = new ConcurrentHashMap<NodeElement, Set<NodeAttribute>>();
32  
33      public Set<NodeElement> getVisitedElements() {
34          return visitedElements;
35      }
36  
37      public ConcurrentMap<NodeElement, Set<NodeAttribute>> getVisitedAttributes() {
38          return visitedAttributes;
39      }
40  
41      @Override
42      protected void visitElement(NodeElement element) {
43          visitedElements.add(element);
44      }
45  
46      @Override
47      protected void visitAttributes(NodeElement element, List<NodeAttribute> attributes) {
48          getVisitedAttributesForElement(element).addAll(attributes);
49      }
50  
51      private Set<NodeAttribute> getVisitedAttributesForElement(NodeElement element) {
52          Set<NodeAttribute> set = visitedAttributes.get(element);
53          if (set == null) {
54              set = new HashSet<NodeAttribute>();
55              Set<NodeAttribute> prev = visitedAttributes.putIfAbsent(element, set);
56              if (prev != null) {
57                  set = prev;
58              }
59          }
60          return set;
61      }
62  }