| /* |
| * 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.util; |
| |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.search.DocIdSet; |
| import org.apache.lucene.search.DocIdSetIterator; |
| |
| /** |
| * This {@link DocIdSet} encodes the negation of another {@link DocIdSet}. |
| * It is cacheable and supports random-access if the underlying set is |
| * cacheable and supports random-access. |
| * @lucene.internal |
| */ |
| public final class NotDocIdSet extends DocIdSet { |
| |
| private static final long BASE_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(NotDocIdSet.class); |
| |
| private final int maxDoc; |
| private final DocIdSet in; |
| |
| /** Sole constructor. */ |
| public NotDocIdSet(int maxDoc, DocIdSet in) { |
| this.maxDoc = maxDoc; |
| this.in = in; |
| } |
| |
| @Override |
| public Bits bits() throws IOException { |
| final Bits inBits = in.bits(); |
| if (inBits == null) { |
| return null; |
| } |
| return new Bits() { |
| |
| @Override |
| public boolean get(int index) { |
| return !inBits.get(index); |
| } |
| |
| @Override |
| public int length() { |
| return inBits.length(); |
| } |
| |
| }; |
| } |
| |
| @Override |
| public long ramBytesUsed() { |
| return BASE_RAM_BYTES_USED + in.ramBytesUsed(); |
| } |
| |
| @Override |
| public DocIdSetIterator iterator() throws IOException { |
| final DocIdSetIterator inIterator = in.iterator(); |
| return new DocIdSetIterator() { |
| |
| int doc = -1; |
| int nextSkippedDoc = -1; |
| |
| @Override |
| public int nextDoc() throws IOException { |
| return advance(doc + 1); |
| } |
| |
| @Override |
| public int advance(int target) throws IOException { |
| doc = target; |
| if (doc > nextSkippedDoc) { |
| nextSkippedDoc = inIterator.advance(doc); |
| } |
| while (true) { |
| if (doc >= maxDoc) { |
| return doc = NO_MORE_DOCS; |
| } |
| assert doc <= nextSkippedDoc; |
| if (doc != nextSkippedDoc) { |
| return doc; |
| } |
| doc += 1; |
| nextSkippedDoc = inIterator.nextDoc(); |
| } |
| } |
| |
| @Override |
| public int docID() { |
| return doc; |
| } |
| |
| @Override |
| public long cost() { |
| // even if there are few docs in this set, iterating over all documents |
| // costs O(maxDoc) in all cases |
| return maxDoc; |
| } |
| }; |
| } |
| |
| } |