| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.lucene.search.grouping; |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.search.Scorable; |
| import org.apache.lucene.search.ScoreMode; |
| import org.apache.lucene.search.SimpleCollector; |
| |
| /** |
| * A collector that collects all groups that match the |
| * query. Only the group value is collected, and the order |
| * is undefined. This collector does not determine |
| * the most relevant document of a group. |
| * |
| * @lucene.experimental |
| */ |
| public class AllGroupsCollector<T> extends SimpleCollector { |
| |
| private final GroupSelector<T> groupSelector; |
| |
| private final Set<T> groups = new HashSet<T>(); |
| |
| /** |
| * Create a new AllGroupsCollector |
| * @param groupSelector the GroupSelector to determine groups |
| */ |
| public AllGroupsCollector(GroupSelector<T> groupSelector) { |
| this.groupSelector = groupSelector; |
| } |
| |
| /** |
| * Returns the total number of groups for the executed search. |
| * This is a convenience method. The following code snippet has the same effect: <pre>getGroups().size()</pre> |
| * |
| * @return The total number of groups for the executed search |
| */ |
| public int getGroupCount() { |
| return getGroups().size(); |
| } |
| |
| /** |
| * Returns the group values |
| * <p> |
| * This is an unordered collections of group values. |
| * |
| * @return the group values |
| */ |
| public Collection<T> getGroups() { |
| return groups; |
| } |
| |
| @Override |
| public void setScorer(Scorable scorer) throws IOException {} |
| |
| @Override |
| protected void doSetNextReader(LeafReaderContext context) throws IOException { |
| groupSelector.setNextReader(context); |
| } |
| |
| @Override |
| public void collect(int doc) throws IOException { |
| groupSelector.advanceTo(doc); |
| if (groups.contains(groupSelector.currentValue())) |
| return; |
| groups.add(groupSelector.copyValue()); |
| } |
| |
| @Override |
| public ScoreMode scoreMode() { |
| return ScoreMode.COMPLETE_NO_SCORES; // the result is unaffected by relevancy |
| } |
| } |