/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.lucene.expressions;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.search.Scorer;
import java.io.IOException;
import java.util.Map;
/**
* A {@link ValueSource} which uses the {@link Scorer} passed through
* the context map by {@link ExpressionComparator}.
*/
@SuppressWarnings({"rawtypes"})
class ScoreValueSource extends ValueSource {
/**
* <code>context</code> must contain a key "scorer" which is a {@link Scorer}.
*/
@Override
public FunctionValues getValues(Map context, LeafReaderContext readerContext) throws IOException {
Scorer v = (Scorer) context.get("scorer");
if (v == null) {
throw new IllegalStateException("Expressions referencing the score can only be used for sorting");
}
return new ScoreFunctionValues(this, v);
}
@Override
public boolean equals(Object o) {
return o == this;
}
@Override
public int hashCode() {
return System.identityHashCode(this);
}
@Override
public String description() {
return "score()";
}
}