package org.apache.lucene.facet.taxonomy;
/*
* 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.
*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import org.apache.lucene.facet.FacetResult;
import org.apache.lucene.facet.Facets;
import org.apache.lucene.facet.FacetsConfig.DimConfig; // javadocs
import org.apache.lucene.facet.FacetsConfig;
/** Base class for all taxonomy-based facets impls. */
public abstract class TaxonomyFacets extends Facets {
private static final Comparator<FacetResult> BY_VALUE_THEN_DIM = new Comparator<FacetResult>() {
@Override
public int compare(FacetResult a, FacetResult b) {
if (a.value.doubleValue() > b.value.doubleValue()) {
return -1;
} else if (b.value.doubleValue() > a.value.doubleValue()) {
return 1;
} else {
return a.dim.compareTo(b.dim);
}
}
};
/** Index field name provided to the constructor. */
protected final String indexFieldName;
/** {@code TaxonomyReader} provided to the constructor. */
protected final TaxonomyReader taxoReader;
/** {@code FacetsConfig} provided to the constructor. */
protected final FacetsConfig config;
/** Maps parent ordinal to its child, or -1 if the parent
* is childless. */
protected final int[] children;
/** Maps an ordinal to its sibling, or -1 if there is no
* sibling. */
protected final int[] siblings;
/** Sole constructor. */
protected TaxonomyFacets(String indexFieldName, TaxonomyReader taxoReader, FacetsConfig config) throws IOException {
this.indexFieldName = indexFieldName;
this.taxoReader = taxoReader;
this.config = config;
ParallelTaxonomyArrays pta = taxoReader.getParallelTaxonomyArrays();
children = pta.children();
siblings = pta.siblings();
}
/** Throws {@code IllegalArgumentException} if the
* dimension is not recognized. Otherwise, returns the
* {@link DimConfig} for this dimension. */
protected FacetsConfig.DimConfig verifyDim(String dim) {
FacetsConfig.DimConfig dimConfig = config.getDimConfig(dim);
if (!dimConfig.indexFieldName.equals(indexFieldName)) {
throw new IllegalArgumentException("dimension \"" + dim + "\" was not indexed into field \"" + indexFieldName);
}
return dimConfig;
}
@Override
public List<FacetResult> getAllDims(int topN) throws IOException {
int ord = children[TaxonomyReader.ROOT_ORDINAL];
List<FacetResult> results = new ArrayList<FacetResult>();
while (ord != TaxonomyReader.INVALID_ORDINAL) {
String dim = taxoReader.getPath(ord).components[0];
FacetsConfig.DimConfig dimConfig = config.getDimConfig(dim);
if (dimConfig.indexFieldName.equals(indexFieldName)) {
FacetResult result = getTopChildren(topN, dim);
if (result != null) {
results.add(result);
}
}
ord = siblings[ord];
}
// Sort by highest value, tie break by dim:
Collections.sort(results, BY_VALUE_THEN_DIM);
return results;
}
}