/*
* 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.solr.ltr;
import org.apache.solr.search.SolrIndexSearcher;
/**
* FeatureLogger can be registered in a model and provide a strategy for logging
* the feature values.
*/
public abstract class FeatureLogger {
/** the name of the cache using for storing the feature value **/
private final String fvCacheName;
public enum FeatureFormat {DENSE, SPARSE};
protected final FeatureFormat featureFormat;
protected FeatureLogger(String fvCacheName, FeatureFormat f) {
this.fvCacheName = fvCacheName;
this.featureFormat = f;
}
/**
* Log will be called every time that the model generates the feature values
* for a document and a query.
*
* @param docid
* Solr document id whose features we are saving
* @param featuresInfo
* List of all the {@link LTRScoringQuery.FeatureInfo} objects which contain name and value
* for all the features triggered by the result set
* @return true if the logger successfully logged the features, false
* otherwise.
*/
public boolean log(int docid, LTRScoringQuery scoringQuery,
SolrIndexSearcher searcher, LTRScoringQuery.FeatureInfo[] featuresInfo) {
final String featureVector = makeFeatureVector(featuresInfo);
if (featureVector == null) {
return false;
}
return searcher.cacheInsert(fvCacheName,
fvCacheKey(scoringQuery, docid), featureVector) != null;
}
public abstract String makeFeatureVector(LTRScoringQuery.FeatureInfo[] featuresInfo);
private static int fvCacheKey(LTRScoringQuery scoringQuery, int docid) {
return scoringQuery.hashCode() + (31 * docid);
}
/**
* populate the document with its feature vector
*
* @param docid
* Solr document id
* @return String representation of the list of features calculated for docid
*/
public String getFeatureVector(int docid, LTRScoringQuery scoringQuery,
SolrIndexSearcher searcher) {
return (String) searcher.cacheLookup(fvCacheName, fvCacheKey(scoringQuery, docid));
}
}