lucene/test-framework/src/java/org/apache/lucene/index/AllDeletedFilterReader.java

/*
 * 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.index;

import org.apache.lucene.util.Bits;

/**
 * Filters the incoming reader and makes all documents appear deleted.
 */
public class AllDeletedFilterReader extends FilterLeafReader {
  final Bits liveDocs;
  
  public AllDeletedFilterReader(LeafReader in) {
    super(in);
    liveDocs = new Bits.MatchNoBits(in.maxDoc());
    assert maxDoc() == 0 || hasDeletions();
  }

  @Override
  public Bits getLiveDocs() {
    return liveDocs;
  }

  @Override
  public int numDocs() {
    return 0;
  }

  @Override
  public CacheHelper getCoreCacheHelper() {
    return in.getCoreCacheHelper();
  }

  @Override
  public CacheHelper getReaderCacheHelper() {
    return null;
  }
}