From c77abca31a6dd5394b691b8283d3720b94409798 Mon Sep 17 00:00:00 2001
From: Patrick Barron <barronpm@gmail.com>
Date: Wed, 29 Jul 2020 17:33:40 -0400
Subject: [PATCH] Use MemoryCache in ChannelManager

---
 .../Channels/ChannelManager.cs                | 23 ++++++++-----------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/Emby.Server.Implementations/Channels/ChannelManager.cs b/Emby.Server.Implementations/Channels/ChannelManager.cs
index c803d9d825..4c3161ef4b 100644
--- a/Emby.Server.Implementations/Channels/ChannelManager.cs
+++ b/Emby.Server.Implementations/Channels/ChannelManager.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
@@ -22,6 +21,7 @@ using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.IO;
 using MediaBrowser.Model.Querying;
 using MediaBrowser.Model.Serialization;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using Episode = MediaBrowser.Controller.Entities.TV.Episode;
 using Movie = MediaBrowser.Controller.Entities.Movies.Movie;
@@ -45,10 +45,7 @@ namespace Emby.Server.Implementations.Channels
         private readonly IFileSystem _fileSystem;
         private readonly IJsonSerializer _jsonSerializer;
         private readonly IProviderManager _providerManager;
-
-        private readonly ConcurrentDictionary<string, Tuple<DateTime, List<MediaSourceInfo>>> _channelItemMediaInfo =
-            new ConcurrentDictionary<string, Tuple<DateTime, List<MediaSourceInfo>>>();
-
+        private readonly IMemoryCache _memoryCache;
         private readonly SemaphoreSlim _resourcePool = new SemaphoreSlim(1, 1);
 
         /// <summary>
@@ -63,6 +60,7 @@ namespace Emby.Server.Implementations.Channels
         /// <param name="userDataManager">The user data manager.</param>
         /// <param name="jsonSerializer">The JSON serializer.</param>
         /// <param name="providerManager">The provider manager.</param>
+        /// <param name="memoryCache">The memory cache.</param>
         public ChannelManager(
             IUserManager userManager,
             IDtoService dtoService,
@@ -72,7 +70,8 @@ namespace Emby.Server.Implementations.Channels
             IFileSystem fileSystem,
             IUserDataManager userDataManager,
             IJsonSerializer jsonSerializer,
-            IProviderManager providerManager)
+            IProviderManager providerManager,
+            IMemoryCache memoryCache)
         {
             _userManager = userManager;
             _dtoService = dtoService;
@@ -83,6 +82,7 @@ namespace Emby.Server.Implementations.Channels
             _userDataManager = userDataManager;
             _jsonSerializer = jsonSerializer;
             _providerManager = providerManager;
+            _memoryCache = memoryCache;
         }
 
         internal IChannel[] Channels { get; private set; }
@@ -417,20 +417,15 @@ namespace Emby.Server.Implementations.Channels
 
         private async Task<IEnumerable<MediaSourceInfo>> GetChannelItemMediaSourcesInternal(IRequiresMediaInfoCallback channel, string id, CancellationToken cancellationToken)
         {
-            if (_channelItemMediaInfo.TryGetValue(id, out Tuple<DateTime, List<MediaSourceInfo>> cachedInfo))
+            if (_memoryCache.TryGetValue(id, out List<MediaSourceInfo> cachedInfo))
             {
-                if ((DateTime.UtcNow - cachedInfo.Item1).TotalMinutes < 5)
-                {
-                    return cachedInfo.Item2;
-                }
+                return cachedInfo;
             }
 
             var mediaInfo = await channel.GetChannelItemMediaInfo(id, cancellationToken)
                    .ConfigureAwait(false);
             var list = mediaInfo.ToList();
-
-            var item2 = new Tuple<DateTime, List<MediaSourceInfo>>(DateTime.UtcNow, list);
-            _channelItemMediaInfo.AddOrUpdate(id, item2, (key, oldValue) => item2);
+            _memoryCache.CreateEntry(id).SetValue(list).SetAbsoluteExpiration(DateTimeOffset.UtcNow.AddMinutes(5));
 
             return list;
         }