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Elasticsearch subproject :server
/*
* 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 org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Scorer;
import org.elasticsearch.script.ExplainableSearchScript;
import org.elasticsearch.script.LeafSearchScript;
import org.elasticsearch.script.Script;
import org.elasticsearch.script.ScriptException;
import org.elasticsearch.script.SearchScript;
import java.io.IOException;
public class ScriptScoreFunction extends ScoreFunction {
static final class CannedScorer extends Scorer {
protected int docid;
protected float score;
public CannedScorer() {
super(null);
}
@Override
public int docID() {
return docid;
}
@Override
public float score() throws IOException {
return score;
}
@Override
public int freq() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public DocIdSetIterator iterator() {
throw new UnsupportedOperationException();
}
}
private final Script sScript;
private final SearchScript script;
public ScriptScoreFunction(Script sScript, SearchScript script) {
super(CombineFunction.REPLACE);
this.sScript = sScript;
this.script = script;
}
@Override
public LeafScoreFunction getLeafScoreFunction(LeafReaderContext ctx) throws IOException {
final LeafSearchScript leafScript = script.getLeafSearchScript(ctx);
final CannedScorer scorer = new CannedScorer();
leafScript.setScorer(scorer);
return new LeafScoreFunction() {
@Override
public double score(int docId, float subQueryScore) {
leafScript.setDocument(docId);
scorer.docid = docId;
scorer.score = subQueryScore;
double result = leafScript.runAsDouble();
if (Double.isNaN(result)) {
throw new ScriptException("script_score returned NaN");
}
return result;
}
@Override
public Explanation explainScore(int docId, Explanation subQueryScore) throws IOException {
Explanation exp;
if (leafScript instanceof ExplainableSearchScript) {
leafScript.setDocument(docId);
scorer.docid = docId;
scorer.score = subQueryScore.getValue();
exp = ((ExplainableSearchScript) leafScript).explain(subQueryScore);
} else {
double score = score(docId, subQueryScore.getValue());
String explanation = "script score function, computed with script:\"" + sScript + "\"";
if (sScript.getParams() != null) {
explanation += " and parameters: \n" + sScript.getParams().toString();
}
Explanation scoreExp = Explanation.match(
subQueryScore.getValue(), "_score: ",
subQueryScore);
return Explanation.match(
CombineFunction.toFloat(score), explanation,
scoreExp);
}
return exp;
}
};
}
@Override
public boolean needsScores() {
return script.needsScores();
}
@Override
public String toString() {
return "script" + sScript.toString();
}
}