| using System; |
| using System.Collections.Concurrent; |
| using System.Collections.Generic; |
| using System.Diagnostics; |
| |
| namespace Lucene.Net.Store |
| { |
| /* |
| * 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="Directory"/> wrapper that allows <see cref="IndexOutput"/> rate limiting using |
| /// IO context (<see cref="IOContext.UsageContext"/>) specific rate limiters (<see cref="RateLimiter"/>). |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| /// <seealso cref="SetRateLimiter(RateLimiter, IOContext.UsageContext)"/> |
| public sealed class RateLimitedDirectoryWrapper : FilterDirectory |
| { |
| // we need to be volatile here to make sure we see all the values that are set |
| // / modified concurrently |
| private readonly IDictionary<IOContext.UsageContext, RateLimiter> _contextRateLimiters = new ConcurrentDictionary<IOContext.UsageContext, RateLimiter>(); |
| |
| public RateLimitedDirectoryWrapper(Directory wrapped) |
| : base(wrapped) |
| { |
| } |
| |
| public override IndexOutput CreateOutput(string name, IOContext context) |
| { |
| EnsureOpen(); |
| var output = base.CreateOutput(name, context); |
| var limiter = GetRateLimiter(context.Context); |
| if (limiter != null) |
| { |
| return new RateLimitedIndexOutput(limiter, output); |
| } |
| return output; |
| } |
| |
| public override IndexInputSlicer CreateSlicer(string name, IOContext context) |
| { |
| EnsureOpen(); |
| return m_input.CreateSlicer(name, context); |
| } |
| |
| public override void Copy(Directory to, string src, string dest, IOContext context) |
| { |
| EnsureOpen(); |
| m_input.Copy(to, src, dest, context); |
| } |
| |
| private RateLimiter GetRateLimiter(IOContext.UsageContext context) |
| { |
| //if (Debugging.AssertsEnabled) Debugging.Assert(context != null); // LUCENENET NOTE: In .NET, enum can never be null |
| return _contextRateLimiters.TryGetValue(context, out RateLimiter ret) ? ret : null; |
| } |
| |
| /// <summary> |
| /// Sets the maximum (approx) MB/sec allowed by all write IO performed by |
| /// <see cref="IndexOutput"/> created with the given <see cref="IOContext.UsageContext"/>. Pass |
| /// <c>null</c> for <paramref name="mbPerSec"/> to have no limit. |
| /// |
| /// <para/> |
| /// <b>NOTE</b>: For already created <see cref="IndexOutput"/> instances there is no |
| /// guarantee this new rate will apply to them; it will only be guaranteed to |
| /// apply for new created <see cref="IndexOutput"/> instances. |
| /// <para/> |
| /// <b>NOTE</b>: this is an optional operation and might not be respected by |
| /// all <see cref="Directory"/> implementations. Currently only buffered (<see cref="FSDirectory"/>) |
| /// <see cref="Directory"/> implementations use rate-limiting. |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| /// <exception cref="ObjectDisposedException"> if the <see cref="Directory"/> is already disposed |
| /// </exception> |
| public void SetMaxWriteMBPerSec(double? mbPerSec, IOContext.UsageContext context) |
| { |
| EnsureOpen(); |
| //if (context == null) // LUCENENET NOTE: enum values can never be null in .NET |
| //{ |
| // throw new ArgumentException("Context must not be null"); |
| //} |
| //int ord = context.ordinal(); |
| _contextRateLimiters.TryGetValue(context, out RateLimiter limiter); |
| |
| if (mbPerSec == null) |
| { |
| if (limiter != null) |
| { |
| limiter.SetMbPerSec(double.MaxValue); |
| _contextRateLimiters[context] = null; |
| } |
| } |
| else if (limiter != null) |
| { |
| limiter.SetMbPerSec(mbPerSec.Value); |
| _contextRateLimiters[context] = limiter; // cross the mem barrier again |
| } |
| else |
| { |
| _contextRateLimiters[context] = new RateLimiter.SimpleRateLimiter(mbPerSec.Value); |
| } |
| } |
| |
| /// <summary> |
| /// Sets the rate limiter to be used to limit (approx) MB/sec allowed by all IO |
| /// performed with the given context (<see cref="IOContext.UsageContext"/>). Pass <c>null</c> to |
| /// have no limit. |
| /// |
| /// <para/> |
| /// Passing an instance of rate limiter compared to setting it using |
| /// <see cref="SetMaxWriteMBPerSec(double?, IOContext.UsageContext)"/> |
| /// allows to use the same limiter instance across several directories globally |
| /// limiting IO across them. |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| /// <exception cref="ObjectDisposedException"> if the <see cref="Directory"/> is already disposed |
| /// </exception> |
| public void SetRateLimiter(RateLimiter mergeWriteRateLimiter, IOContext.UsageContext context) |
| { |
| EnsureOpen(); |
| _contextRateLimiters[context] = mergeWriteRateLimiter; |
| } |
| |
| /// <summary> |
| /// See <see cref="SetMaxWriteMBPerSec"/>. |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| /// <exception cref="ObjectDisposedException"> if the <see cref="Directory"/> is already disposed |
| /// </exception> |
| public double GetMaxWriteMBPerSec(IOContext.UsageContext context) |
| { |
| EnsureOpen(); |
| var limiter = GetRateLimiter(context); |
| return limiter == null ? 0 : limiter.MbPerSec; |
| } |
| } |
| } |