| /* |
| * 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; |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.index.LeafReaderContext; |
| |
| /** A {@link Collector} which computes statistics for a DocValues field. */ |
| public class DocValuesStatsCollector implements Collector { |
| |
| private final DocValuesStats<?> stats; |
| |
| /** Creates a collector to compute statistics for a DocValues field using the given {@code stats}. */ |
| public DocValuesStatsCollector(DocValuesStats<?> stats) { |
| this.stats = stats; |
| } |
| |
| @Override |
| public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException { |
| boolean shouldProcess = stats.init(context); |
| if (!shouldProcess) { |
| // Stats cannot be computed for this segment, therefore consider all matching documents as a 'miss'. |
| return new LeafCollector() { |
| @Override public void setScorer(Scorable scorer) throws IOException {} |
| |
| @Override |
| public void collect(int doc) throws IOException { |
| // All matching documents in this reader are missing a value |
| stats.addMissing(); |
| } |
| }; |
| } |
| |
| return new LeafCollector() { |
| @Override public void setScorer(Scorable scorer) throws IOException {} |
| |
| @Override |
| public void collect(int doc) throws IOException { |
| stats.accumulate(doc); |
| } |
| }; |
| } |
| |
| @Override |
| public ScoreMode scoreMode() { |
| return ScoreMode.COMPLETE_NO_SCORES; |
| } |
| |
| } |