package org.apache.lucene.facet.enhancements;
import java.io.IOException;
import java.util.List;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.facet.search.PayloadIterator;
import org.apache.lucene.util.Vint8;
import org.apache.lucene.util.Vint8.Position;
/**
* 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.
*/
/**
* A {@link PayloadIterator} for iterating over category posting lists generated
* using {@link EnhancementsCategoryTokenizer}.
*
* @lucene.experimental
*/
public class EnhancementsPayloadIterator extends PayloadIterator {
private CategoryEnhancement[] EnhancedCategories;
int nEnhancements;
private int[] enhancementLength;
private int[] enhancementStart;
/**
* Constructor.
*
* @param enhancementsList
* A list of the {@link CategoryEnhancement}s from the indexing
* params.
* @param indexReader
* A reader of the index.
* @param term
* The category term to iterate.
* @throws IOException
*/
public EnhancementsPayloadIterator(
List<CategoryEnhancement> enhancementsList,
IndexReader indexReader, Term term) throws IOException {
super(indexReader, term);
EnhancedCategories = enhancementsList
.toArray(new CategoryEnhancement[enhancementsList.size()]);
enhancementLength = new int[EnhancedCategories.length];
enhancementStart = new int[EnhancedCategories.length];
}
@Override
public boolean setdoc(int docId) throws IOException {
if (!super.setdoc(docId)) {
return false;
}
// read header - number of enhancements and their lengths
Position position = new Position();
nEnhancements = Vint8.decode(buffer, position);
for (int i = 0; i < nEnhancements; i++) {
enhancementLength[i] = Vint8.decode(buffer, position);
}
// set enhancements start points
enhancementStart[0] = position.pos;
for (int i = 1; i < nEnhancements; i++) {
enhancementStart[i] = enhancementStart[i - 1] + enhancementLength[i - 1];
}
return true;
}
/**
* Get the data of the current category and document for a certain
* enhancement, or {@code null} if no such enhancement exists.
*
* @param enhancedCategory
* The category enhancement to apply.
* @return the data of the current category and document for a certain
* enhancement, or {@code null} if no such enhancement exists.
*/
public Object getCategoryData(CategoryEnhancement enhancedCategory) {
for (int i = 0; i < nEnhancements; i++) {
if (enhancedCategory.equals(EnhancedCategories[i])) {
return enhancedCategory.extractCategoryTokenData(buffer,
enhancementStart[i], enhancementLength[i]);
}
}
return null;
}
}