org.apache.lucene.search.similarities.PerFieldSimilarityWrapper Maven / Gradle / Ivy
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* 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
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package org.apache.lucene.search.similarities;
import org.apache.lucene.index.FieldInvertState;
import org.apache.lucene.search.CollectionStatistics;
import org.apache.lucene.search.TermStatistics;
/**
* Provides the ability to use a different {@link Similarity} for different fields.
*
* Subclasses should implement {@link #get(String)} to return an appropriate
* Similarity (for example, using field-specific parameter values) for the field.
*
* @lucene.experimental
*/
public abstract class PerFieldSimilarityWrapper extends Similarity {
/**
* Sole constructor. (For invocation by subclass
* constructors, typically implicit.)
*/
public PerFieldSimilarityWrapper() {}
@Override
public final long computeNorm(FieldInvertState state) {
return get(state.getName()).computeNorm(state);
}
@Override
public final SimScorer scorer(float boost, CollectionStatistics collectionStats, TermStatistics... termStats) {
return get(collectionStats.field()).scorer(boost, collectionStats, termStats);
}
/**
* Returns a {@link Similarity} for scoring a field.
*/
public abstract Similarity get(String name);
}