| using System; |
| using Lucene.Net.Diagnostics; |
| |
| namespace Lucene.Net.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. |
| */ |
| |
| /// <summary> |
| /// Debugging API for Lucene classes such as <see cref="Index.IndexWriter"/> |
| /// and <see cref="Index.SegmentInfos"/>. |
| /// <para> |
| /// NOTE: Enabling infostreams may cause performance degradation |
| /// in some components. |
| /// </para> |
| /// @lucene.internal |
| /// </summary> |
| public abstract class InfoStream : IDisposable |
| #if FEATURE_CLONEABLE |
| , System.ICloneable |
| #endif |
| { |
| /// <summary> |
| /// Instance of <see cref="InfoStream"/> that does no logging at all. </summary> |
| public static readonly InfoStream NO_OUTPUT = new NoOutput(); |
| |
| private sealed class NoOutput : InfoStream |
| { |
| public override void Message(string component, string message) |
| { |
| if (Debugging.AssertsEnabled) Debugging.Assert(false, "Message() should not be called when IsEnabled returns false"); |
| } |
| |
| public override bool IsEnabled(string component) |
| { |
| return false; |
| } |
| |
| protected override void Dispose(bool disposing) |
| { |
| } |
| } |
| |
| /// <summary> |
| /// Prints a message </summary> |
| public abstract void Message(string component, string message); |
| |
| /// <summary> |
| /// Returns <c>true</c> if messages are enabled and should be posted to <see cref="Message(string, string)"/>. </summary> |
| public abstract bool IsEnabled(string component); |
| |
| private static InfoStream defaultInfoStream = NO_OUTPUT; |
| |
| /// <summary> |
| /// Gets or Sets the default <see cref="InfoStream"/> used by a newly instantiated classes. </summary> |
| public static InfoStream Default |
| { |
| get |
| { |
| lock (typeof(InfoStream)) |
| { |
| return defaultInfoStream; |
| } |
| } |
| set |
| { |
| lock (typeof(InfoStream)) |
| { |
| defaultInfoStream = value ?? throw new ArgumentNullException( |
| nameof(value), |
| "Cannot set InfoStream default implementation to null. " + |
| "To disable logging use InfoStream.NO_OUTPUT"); |
| } |
| } |
| } |
| |
| // LUCENENET specific - implementing proper dispose pattern |
| /// <summary> |
| /// Disposes this <see cref="InfoStream"/> |
| /// </summary> |
| public void Dispose() |
| { |
| Dispose(true); |
| GC.SuppressFinalize(this); |
| } |
| |
| /// <summary> |
| /// Disposes this <see cref="InfoStream"/> |
| /// </summary> |
| protected virtual void Dispose(bool disposing) |
| { |
| } |
| |
| /// <summary> |
| /// Clones this <see cref="InfoStream"/> |
| /// </summary> |
| public virtual object Clone() |
| { |
| try |
| { |
| return (InfoStream)base.MemberwiseClone(); |
| } |
| catch (InvalidOperationException e) |
| { |
| throw new Exception(e.ToString(), e); |
| } |
| } |
| } |
| } |