package org.apache.lucene.facet.sampling;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.lucene.facet.old.OldFacetsAccumulator;
import org.apache.lucene.facet.old.ScoredDocIDs;
import org.apache.lucene.facet.params.FacetSearchParams;
import org.apache.lucene.facet.partitions.PartitionsFacetResultsHandler;
import org.apache.lucene.facet.sampling.Sampler.SampleResult;
import org.apache.lucene.facet.search.FacetRequest;
import org.apache.lucene.facet.search.FacetResult;
import org.apache.lucene.facet.taxonomy.TaxonomyReader;
/*
* 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.
*/
/**
* Wrap any Facets Accumulator with sampling.
* <p>
* Note: Sampling accumulation (Accumulation over a sampled-set of the results),
* does not guarantee accurate values for
* {@link FacetResult#getNumValidDescendants()}.
*
* @lucene.experimental
*/
public class SamplingWrapper extends OldFacetsAccumulator {
private OldFacetsAccumulator delegee;
private Sampler sampler;
public SamplingWrapper(OldFacetsAccumulator delegee, Sampler sampler) {
super(delegee.searchParams, delegee.indexReader, delegee.taxonomyReader);
this.delegee = delegee;
this.sampler = sampler;
}
@Override
public List<FacetResult> accumulate(ScoredDocIDs docids) throws IOException {
// Replacing the original searchParams with the over-sampled (and without statistics-compute)
FacetSearchParams original = delegee.searchParams;
boolean shouldOversample = sampler.samplingParams.shouldOverSample();
if (shouldOversample) {
delegee.searchParams = sampler.overSampledSearchParams(original);
}
SampleResult sampleSet = sampler.getSampleSet(docids);
List<FacetResult> sampleRes = delegee.accumulate(sampleSet.docids);
List<FacetResult> results = new ArrayList<FacetResult>();
SampleFixer sampleFixer = sampler.samplingParams.getSampleFixer();
for (FacetResult fres : sampleRes) {
// for sure fres is not null because this is guaranteed by the delegee.
FacetRequest fr = fres.getFacetRequest();
PartitionsFacetResultsHandler frh = createFacetResultsHandler(fr, createOrdinalValueResolver(fr));
if (sampleFixer != null) {
// fix the result of current request
sampleFixer.fixResult(docids, fres, sampleSet.actualSampleRatio);
fres = frh.rearrangeFacetResult(fres); // let delegee's handler do any
}
if (shouldOversample) {
// Using the sampler to trim the extra (over-sampled) results
fres = sampler.trimResult(fres);
}
// final labeling if allowed (because labeling is a costly operation)
if (fres.getFacetResultNode().ordinal == TaxonomyReader.INVALID_ORDINAL) {
// category does not exist, add an empty result
results.add(emptyResult(fres.getFacetResultNode().ordinal, fr));
} else {
frh.labelResult(fres);
results.add(fres);
}
}
if (shouldOversample) {
delegee.searchParams = original; // Back to original params
}
return results;
}
@Override
public double getComplementThreshold() {
return delegee.getComplementThreshold();
}
@Override
public void setComplementThreshold(double complementThreshold) {
delegee.setComplementThreshold(complementThreshold);
}
}