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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.index;
20  
21  import java.util.HashSet;
22  import java.util.Set;
23  
24  import org.apache.maven.index.context.IndexingContext;
25  
26  /**
27   * A special reusable filter, that filters the result set to unique Repository-GroupId-ArtifactId combination, leaving
28   * out Version. There is a switch to make the Indexer-wide unique by ignoring repositories too.
29   *
30   * @author cstamas
31   */
32  public class UniqueArtifactFilterPostprocessor implements ArtifactInfoFilter {
33      public static final String COLLAPSED = "COLLAPSED";
34  
35      private final Set<Field> uniqueFields = new HashSet<>();
36  
37      private final Set<String> gas = new HashSet<>();
38  
39      public UniqueArtifactFilterPostprocessor() {}
40  
41      public UniqueArtifactFilterPostprocessor(Set<Field> uniqueFields) {
42          this.uniqueFields.addAll(uniqueFields);
43      }
44  
45      public boolean accepts(IndexingContext ctx, ArtifactInfo ai) {
46          StringBuilder sb = new StringBuilder();
47  
48          for (Field field : uniqueFields) {
49              sb.append(ai.getFieldValue(field)).append(":");
50          }
51  
52          String key = sb.toString().substring(0, sb.length() - 1);
53  
54          if (gas.contains(key)) {
55              return false;
56          } else {
57              gas.add(key);
58  
59              postprocess(ctx, ai);
60  
61              return true;
62          }
63      }
64  
65      public void postprocess(IndexingContext ctx, ArtifactInfo ai) {
66          for (Field field : ai.getFields()) {
67              if (!uniqueFields.contains(field)) {
68                  ai.setFieldValue(field, COLLAPSED);
69              }
70          }
71      }
72  
73      public void addField(Field field) {
74          uniqueFields.add(field);
75      }
76  }