package org.apache.lucene.util;
/**
* 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.util.BitSet;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
/** Simple DocIdSet and DocIdSetIterator backed by a BitSet */
public class DocIdBitSet extends DocIdSet {
private BitSet bitSet;
public DocIdBitSet(BitSet bitSet) {
this.bitSet = bitSet;
}
@Override
public DocIdSetIterator iterator() {
return new DocIdBitSetIterator(bitSet);
}
/** This DocIdSet implementation is cacheable. */
@Override
public boolean isCacheable() {
return true;
}
/**
* Returns the underlying BitSet.
*/
public BitSet getBitSet() {
return this.bitSet;
}
private static class DocIdBitSetIterator extends DocIdSetIterator {
private int docId;
private BitSet bitSet;
DocIdBitSetIterator(BitSet bitSet) {
this.bitSet = bitSet;
this.docId = -1;
}
@Override
public int docID() {
return docId;
}
@Override
public int nextDoc() {
// (docId + 1) on next line requires -1 initial value for docNr:
int d = bitSet.nextSetBit(docId + 1);
// -1 returned by BitSet.nextSetBit() when exhausted
docId = d == -1 ? NO_MORE_DOCS : d;
return docId;
}
@Override
public int advance(int target) {
int d = bitSet.nextSetBit(target);
// -1 returned by BitSet.nextSetBit() when exhausted
docId = d == -1 ? NO_MORE_DOCS : d;
return docId;
}
}
}