org.elasticsearch.common.lucene.search.function.BoostScoreFunction Maven / Gradle / Ivy
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* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.IndexReader;
import org.apache.lucene.search.Explanation;
/**
* @author kimchy (shay.banon)
*/
public class BoostScoreFunction implements ScoreFunction {
private final float boost;
public BoostScoreFunction(float boost) {
this.boost = boost;
}
public float getBoost() {
return boost;
}
@Override public void setNextReader(IndexReader reader) {
// nothing to do here...
}
@Override public float score(int docId, float subQueryScore) {
return subQueryScore * boost;
}
@Override public Explanation explain(int docId, Explanation subQueryExpl) {
Explanation exp = new Explanation(boost * subQueryExpl.getValue(), "static boost function: product of:");
exp.addDetail(subQueryExpl);
exp.addDetail(new Explanation(boost, "boostFactor"));
return exp;
}
@Override public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
BoostScoreFunction that = (BoostScoreFunction) o;
if (Float.compare(that.boost, boost) != 0) return false;
return true;
}
@Override public int hashCode() {
return (boost != +0.0f ? Float.floatToIntBits(boost) : 0);
}
}