77 lines
3.2 KiB
Java
77 lines
3.2 KiB
Java
/*
|
|
* 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 it.cavallium.dbengine.lucene.collector;
|
|
|
|
import it.cavallium.dbengine.lucene.FullDocs;
|
|
import it.cavallium.dbengine.lucene.LLDoc;
|
|
import it.cavallium.dbengine.lucene.LazyFullDocs;
|
|
import it.cavallium.dbengine.lucene.PriorityQueue;
|
|
import it.cavallium.dbengine.lucene.ResourceIterable;
|
|
import it.cavallium.dbengine.lucene.Reversable;
|
|
import it.cavallium.dbengine.lucene.ReversableResourceIterable;
|
|
import java.io.Closeable;
|
|
import org.apache.lucene.search.Collector;
|
|
import org.apache.lucene.search.TopDocs;
|
|
import org.apache.lucene.search.TotalHits;
|
|
|
|
/**
|
|
* A base class for all collectors that return a {@link TopDocs} output. This collector allows easy
|
|
* extension by providing a single constructor which accepts a {@link PriorityQueue} as well as
|
|
* protected members for that priority queue and a counter of the number of total hits.<br>
|
|
* Extending classes can override any of the methods to provide their own implementation, as well as
|
|
* avoid the use of the priority queue entirely by passing null to {@link
|
|
* #FullDocsCollector(PriorityQueue)}. In that case however, you might want to consider overriding
|
|
* all methods, in order to avoid a NullPointerException.
|
|
*/
|
|
public abstract class FullDocsCollector<PQ extends PriorityQueue<INTERNAL> & Reversable<ReversableResourceIterable<INTERNAL>>, INTERNAL extends LLDoc,
|
|
EXTERNAL extends LLDoc> implements Collector, AutoCloseable {
|
|
|
|
/**
|
|
* The priority queue which holds the top documents. Note that different implementations of
|
|
* PriorityQueue give different meaning to 'top documents'. HitQueue for example aggregates the
|
|
* top scoring documents, while other PQ implementations may hold documents sorted by other
|
|
* criteria.
|
|
*/
|
|
protected final PQ pq;
|
|
|
|
/** The total number of documents that the collector encountered. */
|
|
protected int totalHits;
|
|
|
|
/** Whether {@link #totalHits} is exact or a lower bound. */
|
|
protected TotalHits.Relation totalHitsRelation = TotalHits.Relation.EQUAL_TO;
|
|
|
|
protected FullDocsCollector(PQ pq) {
|
|
this.pq = pq;
|
|
}
|
|
|
|
/** The total number of documents that matched this query. */
|
|
public int getTotalHits() {
|
|
return totalHits;
|
|
}
|
|
|
|
/** Returns the top docs that were collected by this collector. */
|
|
public FullDocs<EXTERNAL> fullDocs() {
|
|
return new LazyFullDocs<>(mapResults(this.pq.reverse()), new TotalHits(totalHits, totalHitsRelation));
|
|
}
|
|
|
|
public abstract ResourceIterable<EXTERNAL> mapResults(ResourceIterable<INTERNAL> it);
|
|
|
|
@Override
|
|
public void close() throws Exception {
|
|
pq.close();
|
|
}
|
|
} |