/*
* 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.exoplatform.services.jcr.impl.core.query.lucene;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.Similarity;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.Weight;
import org.exoplatform.services.jcr.impl.core.SessionImpl;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
/**
* <code>QueryHitsQuery</code> exposes a {@link QueryHits} implementation again
* as a Lucene Query.
*/
public class QueryHitsQuery extends Query implements JcrQuery{
/**
* The underlying query hits.
*/
private final QueryHits hits;
/**
* Creates a new query based on {@link QueryHits}.
*
* @param hits the query hits.
*/
public QueryHitsQuery(QueryHits hits) {
this.hits = hits;
}
/**
* {@inheritDoc}
*/
@Override
public Weight createWeight(Searcher searcher) throws IOException {
return new QueryHitsQueryWeight(searcher.getSimilarity());
}
/**
* {@inheritDoc}
*/
@Override
public String toString(String field) {
return "QueryHitsQuery";
}
/**
* {@inheritDoc}
*/
@Override
public void extractTerms(Set terms) {
// no terms
}
//-----------------------< JackrabbitQuery >--------------------------------
/**
* {@inheritDoc}
*/
public QueryHits execute(JcrIndexSearcher searcher,
SessionImpl session,
Sort sort) throws IOException {
if (sort.getSort().length == 0) {
return hits;
} else {
return null;
}
}
//------------------------< QueryHitsQueryWeight >--------------------------
/**
* The Weight implementation for this query.
*/
public class QueryHitsQueryWeight extends Weight {
/**
* The similarity.
*/
private final Similarity similarity;
/**
* Creates a new weight with the given <code>similarity</code>.
*
* @param similarity the similarity.
*/
public QueryHitsQueryWeight(Similarity similarity) {
this.similarity = similarity;
}
/**
* {@inheritDoc}
*/
@Override
public Query getQuery() {
return QueryHitsQuery.this;
}
/**
* {@inheritDoc}
*/
@Override
public float getValue() {
return 1.0f;
}
/**
* {@inheritDoc}
*/
@Override
public float sumOfSquaredWeights() throws IOException {
return 1.0f;
}
/**
* {@inheritDoc}
*/
@Override
public void normalize(float norm) {
}
/**
* {@inheritDoc}
*/
@Override
public Scorer scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) throws IOException {
return new QueryHitsQueryScorer(reader, similarity);
}
/**
* {@inheritDoc}
*/
@Override
public Explanation explain(IndexReader reader, int doc) throws IOException {
return new Explanation();
}
}
//-------------------< QueryHitsQueryScorer >-------------------------------
/**
* the scorer implementation for this query.
*/
public class QueryHitsQueryScorer extends Scorer {
/**
* Iterator over <code>Integer</code> instances identifying the
* lucene documents. Document numbers are iterated in ascending order.
*/
private final Iterator docs;
/**
* Maps <code>Integer</code> document numbers to <code>Float</code>
* scores.
*/
private final Map scores = new HashMap();
/**
* The current document number.
*/
private Integer currentDoc = null;
/**
* Creates a new scorer.
*
* @param reader the index reader.
* @param similarity the similarity implementation.
* @throws IOException if an error occurs while reading from the index.
*/
protected QueryHitsQueryScorer(IndexReader reader,
Similarity similarity)
throws IOException {
super(similarity);
ScoreNode node;
Set sortedDocs = new TreeSet();
try {
while ((node = hits.nextScoreNode()) != null) {
String uuid = node.getNodeId();
Term id = new Term(FieldNames.UUID, uuid);
TermDocs tDocs = reader.termDocs(id);
try {
if (tDocs.next()) {
Integer doc = new Integer(tDocs.doc());
sortedDocs.add(doc);
scores.put(doc, new Float(node.getScore()));
}
} finally {
tDocs.close();
}
}
} finally {
hits.close();
}
docs = sortedDocs.iterator();
}
/**
* {@inheritDoc}
*/
@Override
public boolean next() throws IOException {
if (docs.hasNext()) {
currentDoc = (Integer) docs.next();
return true;
}
return false;
}
/**
* {@inheritDoc}
*/
@Override
public int doc() {
return currentDoc.intValue();
}
/**
* {@inheritDoc}
*/
@Override
public float score() throws IOException {
return ((Float) scores.get(currentDoc)).floatValue();
}
/**
* {@inheritDoc}
*/
@Override
public boolean skipTo(int target) throws IOException {
do {
if (!next()) {
return false;
}
} while (target > doc());
return true;
}
/**
* {@inheritDoc}
*/
@Override
public Explanation explain(int doc) throws IOException {
return new Explanation();
}
}
}