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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.script;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Scorable;
import org.elasticsearch.common.logging.DeprecationCategory;
import org.elasticsearch.common.logging.DeprecationLogger;
import org.elasticsearch.search.lookup.SearchLookup;
import org.elasticsearch.search.lookup.SourceLookup;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.HashMap;
import java.util.Map;
import java.util.function.DoubleSupplier;
import java.util.function.Function;
/**
* A script used for adjusting the score on a per document basis.
*/
public abstract class ScoreScript extends DocBasedScript {
/** A helper to take in an explanation from a script and turn it into an {@link org.apache.lucene.search.Explanation} */
public static class ExplanationHolder {
private String description;
/**
* Explain the current score.
*
* @param description A textual description of how the score was calculated
*/
public void set(String description) {
this.description = description;
}
public Explanation get(double score, Explanation subQueryExplanation) {
if (description == null) {
return null;
}
if (subQueryExplanation != null) {
return Explanation.match(score, description, subQueryExplanation);
}
return Explanation.match(score, description);
}
}
private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(DynamicMap.class);
private static final Map> PARAMS_FUNCTIONS = org.elasticsearch.core.Map.of("doc", value -> {
deprecationLogger.warn(
DeprecationCategory.SCRIPTING,
"score-script_doc",
"Accessing variable [doc] via [params.doc] from within an score-script " + "is deprecated in favor of directly accessing [doc]."
);
return value;
}, "_doc", value -> {
deprecationLogger.warn(
DeprecationCategory.SCRIPTING,
"score-script__doc",
"Accessing variable [doc] via [params._doc] from within an score-script "
+ "is deprecated in favor of directly accessing [doc]."
);
return value;
}, "_source", value -> ((SourceLookup) value).source());
public static final String[] PARAMETERS = new String[] { "explanation" };
/** The generic runtime parameters for the script. */
private final Map params;
private DoubleSupplier scoreSupplier = () -> 0.0;
private final int docBase;
private int docId;
private int shardId = -1;
private String indexName = null;
public ScoreScript(Map params, SearchLookup searchLookup, DocReader docReader) {
// searchLookup parameter is ignored but part of the ScriptFactory contract. It is part of that contract because it's required
// for expressions. Expressions should eventually be transitioned to using DocReader.
super(docReader);
// null check needed b/c of expression engine subclass
if (docReader == null) {
assert params == null;
this.params = null;
;
this.docBase = 0;
} else {
params = new HashMap<>(params);
params.putAll(docReader.docAsMap());
this.params = new DynamicMap(params, PARAMS_FUNCTIONS);
this.docBase = ((DocValuesDocReader) docReader).getLeafReaderContext().docBase;
}
}
public abstract double execute(ExplanationHolder explanation);
/** Return the parameters for this script. */
public Map getParams() {
return params;
}
/** Set the current document to run the script on next. */
public void setDocument(int docid) {
super.setDocument(docid);
this.docId = docid;
}
public void setScorer(Scorable scorer) {
this.scoreSupplier = () -> {
try {
return scorer.score();
} catch (IOException e) {
throw new UncheckedIOException(e);
}
};
}
/**
* Accessed as _score in the painless script
* @return the score of the inner query
*/
public double get_score() {
return scoreSupplier.getAsDouble();
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
* It is only used within predefined painless functions.
* @return the internal document ID
*/
public int _getDocId() {
return docId;
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
* It is only used within predefined painless functions.
* @return the internal document ID with the base
*/
public int _getDocBaseId() {
return docBase + docId;
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
* It is only used within predefined painless functions.
* @return shard id or throws an exception if shard is not set up for this script instance
*/
public int _getShardId() {
if (shardId > -1) {
return shardId;
} else {
throw new IllegalArgumentException("shard id can not be looked up!");
}
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
* It is only used within predefined painless functions.
* @return index name or throws an exception if the index name is not set up for this script instance
*/
public String _getIndex() {
if (indexName != null) {
return indexName;
} else {
throw new IllegalArgumentException("index name can not be looked up!");
}
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
*/
public void _setShard(int shardId) {
this.shardId = shardId;
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
*/
public void _setIndexName(String indexName) {
this.indexName = indexName;
}
/** A factory to construct {@link ScoreScript} instances. */
public interface LeafFactory {
/**
* Return {@code true} if the script needs {@code _score} calculated, or {@code false} otherwise.
*/
boolean needs_score();
ScoreScript newInstance(DocReader reader) throws IOException;
}
/** A factory to construct stateful {@link ScoreScript} factories for a specific index. */
public interface Factory extends ScriptFactory {
// searchLookup is used taken in for compatibility with expressions. See ExpressionScriptEngine.newScoreScript and
// ExpressionScriptEngine.getDocValueSource for where it's used.
ScoreScript.LeafFactory newFactory(Map params, SearchLookup lookup);
}
public static final ScriptContext CONTEXT = new ScriptContext<>("score", ScoreScript.Factory.class);
}