org.elasticsearch.index.query.CustomScoreQueryParser Maven / Gradle / Ivy
/*
* Licensed to ElasticSearch and Shay Banon under one
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* 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.index.query;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Query;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.search.XConstantScoreQuery;
import org.elasticsearch.common.lucene.search.function.FunctionScoreQuery;
import org.elasticsearch.common.lucene.search.function.ScoreFunction;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.script.ExplainableSearchScript;
import org.elasticsearch.script.SearchScript;
import java.io.IOException;
import java.util.Map;
/**
*
*/
public class CustomScoreQueryParser implements QueryParser {
public static final String NAME = "custom_score";
@Inject
public CustomScoreQueryParser() {
}
@Override
public String[] names() {
return new String[]{NAME, Strings.toCamelCase(NAME)};
}
@Override
public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
XContentParser parser = parseContext.parser();
Query query = null;
Filter filter = null;
boolean queryOrFilterFound = false;
float boost = 1.0f;
String script = null;
String scriptLang = null;
Map vars = null;
String currentFieldName = null;
XContentParser.Token token;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token == XContentParser.Token.START_OBJECT) {
if ("query".equals(currentFieldName)) {
query = parseContext.parseInnerQuery();
queryOrFilterFound = true;
} else if ("filter".equals(currentFieldName)) {
filter = parseContext.parseInnerFilter();
queryOrFilterFound = true;
} else if ("params".equals(currentFieldName)) {
vars = parser.map();
} else {
throw new QueryParsingException(parseContext.index(), "[custom_score] query does not support [" + currentFieldName + "]");
}
} else if (token.isValue()) {
if ("script".equals(currentFieldName)) {
script = parser.text();
} else if ("lang".equals(currentFieldName)) {
scriptLang = parser.text();
} else if ("boost".equals(currentFieldName)) {
boost = parser.floatValue();
} else {
throw new QueryParsingException(parseContext.index(), "[custom_score] query does not support [" + currentFieldName + "]");
}
}
}
if (!queryOrFilterFound) {
throw new QueryParsingException(parseContext.index(), "[custom_score] requires 'query' or 'filter' field");
}
if (script == null) {
throw new QueryParsingException(parseContext.index(), "[custom_score] requires 'script' field");
}
if (query == null && filter == null) {
return null;
} else if (filter != null) {
query = new XConstantScoreQuery(filter);
}
SearchScript searchScript;
try {
searchScript = parseContext.scriptService().search(parseContext.lookup(), scriptLang, script, vars);
} catch (Exception e) {
throw new QueryParsingException(parseContext.index(), "[custom_score] the script could not be loaded", e);
}
FunctionScoreQuery functionScoreQuery = new FunctionScoreQuery(query, new ScriptScoreFunction(script, vars, searchScript));
functionScoreQuery.setBoost(boost);
return functionScoreQuery;
}
public static class ScriptScoreFunction implements ScoreFunction {
private final String sScript;
private final Map params;
private final SearchScript script;
public ScriptScoreFunction(String sScript, Map params, SearchScript script) {
this.sScript = sScript;
this.params = params;
this.script = script;
}
@Override
public void setNextReader(AtomicReaderContext ctx) {
//LUCENE 4 UPGRADE should this pass on a ARC or just and atomic reader?
script.setNextReader(ctx);
}
@Override
public float score(int docId, float subQueryScore) {
script.setNextDocId(docId);
script.setNextScore(subQueryScore);
return script.runAsFloat();
}
@Override
public float factor(int docId) {
// just the factor, so don't provide _score
script.setNextDocId(docId);
return script.runAsFloat();
}
@Override
public Explanation explainScore(int docId, Explanation subQueryExpl) {
Explanation exp;
if (script instanceof ExplainableSearchScript) {
script.setNextDocId(docId);
script.setNextScore(subQueryExpl.getValue());
exp = ((ExplainableSearchScript) script).explain(subQueryExpl);
} else {
float score = score(docId, subQueryExpl.getValue());
exp = new Explanation(score, "script score function: composed of:");
exp.addDetail(subQueryExpl);
}
return exp;
}
@Override
public Explanation explainFactor(int docId) {
return new Explanation(factor(docId), "scriptFactor");
}
@Override
public String toString() {
return "script[" + sScript + "], params [" + params + "]";
}
}
}