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/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* 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.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*/
package org.opensearch.script;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Scorable;
import org.opensearch.Version;
import org.opensearch.common.logging.DeprecationLogger;
import org.opensearch.index.fielddata.ScriptDocValues;
import org.opensearch.index.query.functionscore.TermFrequencyFunctionFactory.TermFrequencyFunctionName;
import org.opensearch.search.lookup.LeafSearchLookup;
import org.opensearch.search.lookup.LeafTermFrequencyLookup;
import org.opensearch.search.lookup.SearchLookup;
import org.opensearch.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.
*
* @opensearch.internal
*/
public abstract class ScoreScript {
/**
* A helper to take in an explanation from a script and turn it into an {@link org.apache.lucene.search.Explanation}
*
* @opensearch.internal
*/
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 = Map.of("doc", value -> {
deprecationLogger.deprecate(
"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.deprecate(
"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).loadSourceIfNeeded());
public static final String[] PARAMETERS = new String[] { "explanation" };
/** The generic runtime parameters for the script. */
private final Map params;
/** A leaf lookup for the bound segment this script will operate on. */
private final LeafSearchLookup leafLookup;
/** A leaf term frequency lookup for the bound segment this script will operate on. */
private final LeafTermFrequencyLookup leafTermFrequencyLookup;
private DoubleSupplier scoreSupplier = () -> 0.0;
private final int docBase;
private int docId;
private int shardId = -1;
private String indexName = null;
private Version indexVersion = null;
public ScoreScript(Map params, SearchLookup lookup, IndexSearcher indexSearcher, LeafReaderContext leafContext) {
// null check needed b/c of expression engine subclass
if (lookup == null) {
assert params == null;
assert leafContext == null;
this.params = null;
this.leafLookup = null;
this.leafTermFrequencyLookup = null;
this.docBase = 0;
} else {
this.leafLookup = lookup.getLeafSearchLookup(leafContext);
this.leafTermFrequencyLookup = new LeafTermFrequencyLookup(indexSearcher, leafLookup);
params = new HashMap<>(params);
params.putAll(leafLookup.asMap());
this.params = new DynamicMap(params, PARAMS_FUNCTIONS);
this.docBase = leafContext.docBase;
}
}
public abstract double execute(ExplanationHolder explanation);
/** Return the parameters for this script. */
public Map getParams() {
return params;
}
/** The doc lookup for the Lucene segment this script was created for. */
public Map> getDoc() {
return leafLookup.doc();
}
public Object getTermFrequency(TermFrequencyFunctionName functionName, String field, String val) throws IOException {
return leafTermFrequencyLookup.getTermFrequency(functionName, field, val, docId);
}
/** Set the current document to run the script on next. */
public void setDocument(int docid) {
this.docId = docid;
leafLookup.setDocument(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
* It is only used within predefined painless functions.
* @return index version or throws an exception if the index version is not set up for this script instance
*/
public Version _getIndexVersion() {
if (indexVersion != null) {
return indexVersion;
} else {
throw new IllegalArgumentException("index version 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;
}
/**
* Starting a name with underscore, so that the user cannot access this function directly through a script
*/
public void _setIndexVersion(Version indexVersion) {
this.indexVersion = indexVersion;
}
/**
* A factory to construct {@link ScoreScript} instances.
*
* @opensearch.internal
*/
public interface LeafFactory {
/**
* Return {@code true} if the script needs {@code _score} calculated, or {@code false} otherwise.
*/
boolean needs_score();
ScoreScript newInstance(LeafReaderContext ctx) throws IOException;
}
/**
* A factory to construct stateful {@link ScoreScript} factories for a specific index.
*
* @opensearch.internal
*/
public interface Factory extends ScriptFactory {
ScoreScript.LeafFactory newFactory(Map params, SearchLookup lookup, IndexSearcher indexSearcher);
}
public static final ScriptContext CONTEXT = new ScriptContext<>("score", ScoreScript.Factory.class);
}