| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Index |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// A <see cref="FilterDirectoryReader"/> wraps another <see cref="DirectoryReader"/>, allowing implementations |
| /// to transform or extend it. |
| /// <para/> |
| /// Subclasses should implement <see cref="DoWrapDirectoryReader(DirectoryReader)"/> to return an instance of the |
| /// subclass. |
| /// <para/> |
| /// If the subclass wants to wrap the <see cref="DirectoryReader"/>'s subreaders, it should also |
| /// implement a <see cref="SubReaderWrapper"/> subclass, and pass an instance to its base |
| /// constructor. |
| /// </summary> |
| public abstract class FilterDirectoryReader : DirectoryReader |
| { |
| /// <summary> |
| /// Factory class passed to <see cref="FilterDirectoryReader"/> constructor that allows |
| /// subclasses to wrap the filtered <see cref="DirectoryReader"/>'s subreaders. You |
| /// can use this to, e.g., wrap the subreaders with specialized |
| /// <see cref="FilterAtomicReader"/> implementations. |
| /// </summary> |
| public abstract class SubReaderWrapper |
| { |
| internal virtual AtomicReader[] Wrap(IList<IndexReader> readers) // LUCENENET specific: Changed from IList<AtomicReader> to IList<IndexReader> to eliminate cast in calling method |
| { |
| AtomicReader[] wrapped = new AtomicReader[readers.Count]; |
| for (int i = 0; i < readers.Count; i++) |
| { |
| wrapped[i] = Wrap((AtomicReader)readers[i]); |
| } |
| return wrapped; |
| } |
| |
| /// <summary> |
| /// Constructor </summary> |
| protected SubReaderWrapper() // LUCENENET: CA1012: Abstract types should not have constructors (marked protected) |
| { |
| } |
| |
| /// <summary> |
| /// Wrap one of the parent <see cref="DirectoryReader"/>'s subreaders </summary> |
| /// <param name="reader"> the subreader to wrap </param> |
| /// <returns> a wrapped/filtered <see cref="AtomicReader"/> </returns> |
| public abstract AtomicReader Wrap(AtomicReader reader); |
| } |
| |
| /// <summary> |
| /// A no-op <see cref="SubReaderWrapper"/> that simply returns the parent |
| /// <see cref="DirectoryReader"/>'s original subreaders. |
| /// </summary> |
| public class StandardReaderWrapper : SubReaderWrapper |
| { |
| /// <summary> |
| /// Constructor </summary> |
| public StandardReaderWrapper() |
| { |
| } |
| |
| public override AtomicReader Wrap(AtomicReader reader) |
| { |
| return reader; |
| } |
| } |
| |
| /// <summary> |
| /// The filtered <see cref="DirectoryReader"/> </summary> |
| protected readonly DirectoryReader m_input; |
| |
| /// <summary> |
| /// Create a new <see cref="FilterDirectoryReader"/> that filters a passed in <see cref="DirectoryReader"/>. </summary> |
| /// <param name="input"> the <see cref="DirectoryReader"/> to filter </param> |
| protected FilterDirectoryReader(DirectoryReader input) // LUCENENET: CA1012: Abstract types should not have constructors (marked protected) |
| : this(input, new StandardReaderWrapper()) |
| { |
| } |
| |
| /// <summary> |
| /// Create a new <see cref="FilterDirectoryReader"/> that filters a passed in <see cref="DirectoryReader"/>, |
| /// using the supplied <see cref="SubReaderWrapper"/> to wrap its subreader. </summary> |
| /// <param name="input"> the <see cref="DirectoryReader"/> to filter </param> |
| /// <param name="wrapper"> the <see cref="SubReaderWrapper"/> to use to wrap subreaders </param> |
| protected FilterDirectoryReader(DirectoryReader input, SubReaderWrapper wrapper) // LUCENENET: CA1012: Abstract types should not have constructors (marked protected) |
| : base(input.Directory, wrapper.Wrap(input.GetSequentialSubReaders())) |
| { |
| this.m_input = input; |
| } |
| |
| /// <summary> |
| /// Called by the <see cref="DoOpenIfChanged()"/> methods to return a new wrapped <see cref="DirectoryReader"/>. |
| /// <para/> |
| /// Implementations should just return an instance of themselves, wrapping the |
| /// passed in <see cref="DirectoryReader"/>. |
| /// </summary> |
| /// <param name="input"> the <see cref="DirectoryReader"/> to wrap </param> |
| /// <returns> the wrapped <see cref="DirectoryReader"/> </returns> |
| protected abstract DirectoryReader DoWrapDirectoryReader(DirectoryReader input); |
| |
| private DirectoryReader WrapDirectoryReader(DirectoryReader input) |
| { |
| return input == null ? null : DoWrapDirectoryReader(input); |
| } |
| |
| protected internal override sealed DirectoryReader DoOpenIfChanged() |
| { |
| return WrapDirectoryReader(m_input.DoOpenIfChanged()); |
| } |
| |
| protected internal override sealed DirectoryReader DoOpenIfChanged(IndexCommit commit) |
| { |
| return WrapDirectoryReader(m_input.DoOpenIfChanged(commit)); |
| } |
| |
| protected internal override sealed DirectoryReader DoOpenIfChanged(IndexWriter writer, bool applyAllDeletes) |
| { |
| return WrapDirectoryReader(m_input.DoOpenIfChanged(writer, applyAllDeletes)); |
| } |
| |
| public override long Version => m_input.Version; |
| |
| public override bool IsCurrent() |
| { |
| return m_input.IsCurrent(); |
| } |
| |
| public override IndexCommit IndexCommit => m_input.IndexCommit; |
| |
| protected internal override void DoClose() |
| { |
| m_input.DoClose(); |
| } |
| } |
| } |