package org.apache.lucene.facet.util;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.lucene.facet.search.CategoryListIterator;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.util.IntsRef;
/*
* 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.
*/
/**
* Iterates over multiple {@link CategoryListIterator}s, consuming the provided
* iterators in order.
*
* @lucene.experimental
*/
public class MultiCategoryListIterator implements CategoryListIterator {
private final CategoryListIterator[] iterators;
private final List<CategoryListIterator> validIterators;
/** Receives the iterators to iterate on */
public MultiCategoryListIterator(CategoryListIterator... iterators) {
this.iterators = iterators;
this.validIterators = new ArrayList<CategoryListIterator>();
}
@Override
public boolean setNextReader(AtomicReaderContext context) throws IOException {
validIterators.clear();
for (CategoryListIterator cli : iterators) {
if (cli.setNextReader(context)) {
validIterators.add(cli);
}
}
return !validIterators.isEmpty();
}
@Override
public void getOrdinals(int docID, IntsRef ints) throws IOException {
IntsRef tmp = new IntsRef(ints.length);
for (CategoryListIterator cli : validIterators) {
cli.getOrdinals(docID, tmp);
if (ints.ints.length < ints.length + tmp.length) {
ints.grow(ints.length + tmp.length);
}
ints.length += tmp.length;
}
}
}