| /* |
| * 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.Objects; |
| |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.search.Scorable; |
| import org.apache.lucene.search.ScoreMode; |
| import org.apache.lucene.search.SimpleCollector; |
| |
| /** |
| * SecondPassGroupingCollector runs over an already collected set of |
| * groups, further applying a {@link GroupReducer} to each group |
| * |
| * @see TopGroupsCollector |
| * @see DistinctValuesCollector |
| * |
| * @lucene.experimental |
| */ |
| public class SecondPassGroupingCollector<T> extends SimpleCollector { |
| |
| protected final GroupSelector<T> groupSelector; |
| protected final Collection<SearchGroup<T>> groups; |
| protected final GroupReducer<T, ?> groupReducer; |
| |
| protected int totalHitCount; |
| protected int totalGroupedHitCount; |
| |
| /** |
| * Create a new SecondPassGroupingCollector |
| * @param groupSelector the GroupSelector that defines groups for this search |
| * @param groups the groups to collect documents for |
| * @param reducer the reducer to apply to each group |
| */ |
| public SecondPassGroupingCollector(GroupSelector<T> groupSelector, Collection<SearchGroup<T>> groups, GroupReducer<T, ?> reducer) { |
| |
| //System.out.println("SP init"); |
| if (groups.isEmpty()) { |
| throw new IllegalArgumentException("no groups to collect (groups is empty)"); |
| } |
| |
| this.groupSelector = Objects.requireNonNull(groupSelector); |
| this.groupSelector.setGroups(groups); |
| |
| this.groups = Objects.requireNonNull(groups); |
| this.groupReducer = reducer; |
| reducer.setGroups(groups); |
| } |
| |
| /** |
| * @return the GroupSelector used in this collector |
| */ |
| public GroupSelector<T> getGroupSelector() { |
| return groupSelector; |
| } |
| |
| @Override |
| public ScoreMode scoreMode() { |
| return groupReducer.needsScores() ? ScoreMode.COMPLETE : ScoreMode.COMPLETE_NO_SCORES; |
| } |
| |
| @Override |
| public void setScorer(Scorable scorer) throws IOException { |
| groupSelector.setScorer(scorer); |
| groupReducer.setScorer(scorer); |
| } |
| |
| @Override |
| public void collect(int doc) throws IOException { |
| totalHitCount++; |
| if (groupSelector.advanceTo(doc) == GroupSelector.State.SKIP) |
| return; |
| totalGroupedHitCount++; |
| T value = groupSelector.currentValue(); |
| groupReducer.collect(value, doc); |
| } |
| |
| @Override |
| protected void doSetNextReader(LeafReaderContext readerContext) throws IOException { |
| groupReducer.setNextReader(readerContext); |
| groupSelector.setNextReader(readerContext); |
| } |
| |
| } |