package org.apache.lucene.facet.util;
import org.apache.lucene.facet.index.params.CategoryListParams;
import org.apache.lucene.facet.index.params.FacetIndexingParams;
import org.apache.lucene.facet.search.params.FacetSearchParams;
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.
*/
/**
* Utilities for partitions - sizes and such
*
* @lucene.experimental
*/
public final class PartitionsUtils {
/**
* Get the offset for a given partition. That is, what is the minimum number an
* ordinal could be for a particular partition.
*/
public final static int partitionOffset ( FacetIndexingParams iParams,
int partitionNumber,
final TaxonomyReader taxonomyReader) {
return partitionNumber * partitionSize(iParams, taxonomyReader);
}
/**
* @see #partitionOffset(FacetIndexingParams, int, TaxonomyReader)
*/
public final static int partitionOffset ( FacetSearchParams sParams,
int partitionNumber,
final TaxonomyReader taxonomyReader) {
return partitionOffset(sParams.getFacetIndexingParams(), partitionNumber, taxonomyReader);
}
/**
* Get the partition size in this parameter, or return the size of the taxonomy, which
* is smaller. (Guarantees usage of as little memory as possible at search time).
*/
public final static int partitionSize(FacetIndexingParams indexingParams, final TaxonomyReader taxonomyReader) {
return Math.min(indexingParams.getPartitionSize(), taxonomyReader.getSize());
}
/**
* @see #partitionSize(FacetIndexingParams, TaxonomyReader)
*/
public final static int partitionSize(FacetSearchParams sParams, final TaxonomyReader taxonomyReader) {
return partitionSize(sParams.getFacetIndexingParams(), taxonomyReader);
}
/**
* Partition number of an ordinal.
* <p>
* This allows to locate the partition containing a certain (facet) ordinal.
* @see FacetIndexingParams#getPartitionSize()
*/
public final static int partitionNumber(FacetIndexingParams iParams, int ordinal) {
return ordinal / iParams.getPartitionSize();
}
/**
* @see #partitionNumber(FacetIndexingParams, int)
*/
public final static int partitionNumber(FacetSearchParams sParams, int ordinal) {
return partitionNumber(sParams.getFacetIndexingParams(), ordinal);
}
/**
* Partition name by category ordinal
*/
public final static String partitionNameByOrdinal( FacetIndexingParams iParams,
CategoryListParams clParams,
int ordinal) {
int partition = partitionNumber(iParams, ordinal);
return partitionName(clParams, partition);
}
/**
* Partition name by its number
*/
public final static String partitionName(CategoryListParams clParams, int partition) {
String term = clParams.getTerm().text();
if (partition == 0) {
return term; // for backwards compatibility we do not add a partition number in this case
}
return term + partition;
}
}