package experiments.collective.entdoccentric.LTR;
/*
* 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.
*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import org.apache.lucene.search.Scorer;
/**
* A Scorer for queries with a required part and an optional part. Delays
* skipTo() on the optional part until a score() is needed. <br>
* This <code>Scorer</code> implements {@link Scorer#advance(int)}.
*/
class ReqOptSumScorer extends Scorer {
/**
* The scorers passed from the constructor. These are set to null as soon as
* their next() or skipTo() returns false.
*/
private Scorer reqScorer;
private Scorer optScorer;
/**
* Construct a <code>ReqOptScorer</code>.
*
* @param reqScorer
* The required scorer. This must match.
* @param optScorer
* The optional scorer. This is used for scoring only.
*/
public ReqOptSumScorer(Scorer reqScorer, Scorer optScorer) {
super(reqScorer.getWeight());
assert reqScorer != null;
assert optScorer != null;
this.reqScorer = reqScorer;
this.optScorer = optScorer;
}
@Override
public int nextDoc() throws IOException {
return reqScorer.nextDoc();
}
@Override
public int advance(int target) throws IOException {
return reqScorer.advance(target);
}
@Override
public int docID() {
return reqScorer.docID();
}
/**
* Returns the score of the current document matching the query. Initially
* invalid, until {@link #nextDoc()} is called the first time.
*
* @return The score of the required scorer, eventually increased by the
* score of the optional scorer when it also matches the current
* document.
*/
@Override
public float score() throws IOException {
// TODO: sum into a double and cast to float if we ever send required
// clauses to BS1
int curDoc = reqScorer.docID();
float reqScore = reqScorer.score();
if (optScorer == null) {
return reqScore;
}
int optScorerDoc = optScorer.docID();
if (optScorerDoc < curDoc
&& (optScorerDoc = optScorer.advance(curDoc)) == NO_MORE_DOCS) {
optScorer = null;
return reqScore;
}
return optScorerDoc == curDoc ? reqScore + optScorer.score() : reqScore;
}
@Override
public int freq() throws IOException {
// we might have deferred advance()
score();
return (optScorer != null && optScorer.docID() == reqScorer.docID()) ? 2
: 1;
}
@Override
public Collection<ChildScorer> getChildren() {
ArrayList<ChildScorer> children = new ArrayList<ChildScorer>(2);
children.add(new ChildScorer(reqScorer, "MUST"));
children.add(new ChildScorer(optScorer, "SHOULD"));
return children;
}
}