/*
* 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.
*/
using System;
using IndexReader = Lucene.Net.Index.IndexReader;
using DocIdBitSet = Lucene.Net.Util.DocIdBitSet;
namespace Lucene.Net.Search
{
/// Abstract base class for restricting which documents may be returned during searching.
///
/// Note: In Lucene 3.0 {@link #Bits(IndexReader)} will be removed
/// and {@link #GetDocIdSet(IndexReader)} will be defined as abstract.
/// All implementing classes must therefore implement {@link #GetDocIdSet(IndexReader)}
/// in order to work with Lucene 3.0.
///
[Serializable]
public abstract class Filter
{
/// >NOTE: See {@link #getDocIdSet(IndexReader)} for
/// handling of multi-segment indexes (which applies to
/// this method as well.
/// A BitSet with true for documents which should be permitted in
/// search results, and false for those that should not.
///
/// Use {@link #GetDocIdSet(IndexReader)} instead.
///
[Obsolete("Use GetDocIdSet(IndexReader) instead.")]
public virtual System.Collections.BitArray Bits(IndexReader reader)
{
throw new System.NotSupportedException();
}
///
/// Creates a {@link DocIdSet} enumerating the documents that should be
/// permitted in search results. NOTE: null can be
/// returned if no documents are accepted by this Filter.
///
/// Note: This method will be called once per segment in
/// the index during searching. The returned {@link DocIdSet}
/// must refer to document IDs for that segment, not for
/// the top-level reader.
///
/// @param reader a {@link IndexReader} instance opened on the index currently
/// searched on. Note, it is likely that the provided reader does not
/// represent the whole underlying index i.e. if the index has more than
/// one segment the given reader only represents a single segment.
///
///
/// a DocIdSet that provides the documents which should be permitted or
/// prohibited in search results. NOTE: null can be returned if
/// no documents will be accepted by this Filter.
///
///
///
public virtual DocIdSet GetDocIdSet(IndexReader reader)
{
return new DocIdBitSet(Bits(reader));
}
}
}