/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.common.lucene.search.function;
import org.apache.lucene.index.LeafReaderContext;
import java.io.IOException;
import java.util.Objects;
public abstract class ScoreFunction {
private final CombineFunction scoreCombiner;
protected ScoreFunction(CombineFunction scoreCombiner) {
this.scoreCombiner = scoreCombiner;
}
public CombineFunction getDefaultScoreCombiner() {
return scoreCombiner;
}
public abstract LeafScoreFunction getLeafScoreFunction(LeafReaderContext ctx) throws IOException;
/**
* Indicates if document scores are needed by this function.
*
* @return {@code true} if scores are needed.
*/
public abstract boolean needsScores();
@Override
public final boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
ScoreFunction other = (ScoreFunction) obj;
return Objects.equals(scoreCombiner, other.scoreCombiner) &&
doEquals(other);
}
/**
* Indicates whether some other {@link ScoreFunction} object of the same type is "equal to" this one.
*/
protected abstract boolean doEquals(ScoreFunction other);
@Override
public final int hashCode() {
/*
* Override hashCode here and forward to an abstract method to force extensions of this class to override hashCode in the same
* way that we force them to override equals. This also prevents false positives in CheckStyle's EqualsHashCode check.
*/
return Objects.hash(scoreCombiner, doHashCode());
}
protected abstract int doHashCode();
}