/*
* 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.
*/
package org.apache.lucene.search;
import java.io.IOException;
/**
* A {@link DocIdSetIterator} which is a disjunction of the approximations of
* the provided iterators.
* @lucene.internal
*/
public class DisjunctionDISIApproximation extends DocIdSetIterator {
final DisiPriorityQueue subIterators;
final long cost;
public DisjunctionDISIApproximation(DisiPriorityQueue subIterators) {
this.subIterators = subIterators;
long cost = 0;
for (DisiWrapper w : subIterators) {
cost += w.cost;
}
this.cost = cost;
}
@Override
public long cost() {
return cost;
}
@Override
public int docID() {
return subIterators.top().doc;
}
@Override
public int nextDoc() throws IOException {
DisiWrapper top = subIterators.top();
final int doc = top.doc;
do {
top.doc = top.approximation.nextDoc();
top = subIterators.updateTop();
} while (top.doc == doc);
return top.doc;
}
@Override
public int advance(int target) throws IOException {
DisiWrapper top = subIterators.top();
do {
top.doc = top.approximation.advance(target);
top = subIterators.updateTop();
} while (top.doc < target);
return top.doc;
}
}