Use async requests for media cover proxy

(cherry picked from commit ad1f185330a30a2a9d27c9d3f18d384e66727c2a)

Closes #9183

src/Radarr.Http/Frontend/Mappers/IMapHttpRequestsToDisk.cs

@@ -1,3 +1,4 @@
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 
 namespace Radarr.Http.Frontend.Mappers
@@ -6,6 +7,6 @@ namespace Radarr.Http.Frontend.Mappers
     {
         string Map(string resourceUrl);
         bool CanHandle(string resourceUrl);
-        IActionResult GetResponse(string resourceUrl);
+        Task<IActionResult> GetResponse(string resourceUrl);
     }
 }

src/Radarr.Http/Frontend/Mappers/MediaCoverProxyMapper.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Net;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.StaticFiles;
 using NzbDrone.Core.MediaCover;
@@ -9,7 +10,7 @@ namespace Radarr.Http.Frontend.Mappers
 {
     public class MediaCoverProxyMapper : IMapHttpRequestsToDisk
     {
-        private readonly Regex _regex = new Regex(@"/MediaCoverProxy/(?<hash>\w+)/(?<filename>(.+)\.(jpg|png|gif))");
+        private readonly Regex _regex = new (@"/MediaCoverProxy/(?<hash>\w+)/(?<filename>(.+)\.(jpg|png|gif))");
 
         private readonly IMediaCoverProxy _mediaCoverProxy;
         private readonly IContentTypeProvider _mimeTypeProvider;
@@ -30,7 +31,7 @@ namespace Radarr.Http.Frontend.Mappers
             return resourceUrl.StartsWith("/MediaCoverProxy/", StringComparison.InvariantCultureIgnoreCase);
         }
 
-        public IActionResult GetResponse(string resourceUrl)
+        public async Task<IActionResult> GetResponse(string resourceUrl)
         {
             var match = _regex.Match(resourceUrl);
 
@@ -42,7 +43,7 @@ namespace Radarr.Http.Frontend.Mappers
             var hash = match.Groups["hash"].Value;
             var filename = match.Groups["filename"].Value;
 
-            var imageData = _mediaCoverProxy.GetImage(hash);
+            var imageData = await _mediaCoverProxy.GetImage(hash);
 
             if (!_mimeTypeProvider.TryGetContentType(filename, out var contentType))
             {

src/Radarr.Http/Frontend/Mappers/StaticResourceMapperBase.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Text;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.StaticFiles;
 using Microsoft.Net.Http.Headers;
@@ -30,7 +31,7 @@ namespace Radarr.Http.Frontend.Mappers
 
         public abstract bool CanHandle(string resourceUrl);
 
-        public IActionResult GetResponse(string resourceUrl)
+        public Task<IActionResult> GetResponse(string resourceUrl)
         {
             var filePath = Map(resourceUrl);
 
@@ -41,10 +42,10 @@ namespace Radarr.Http.Frontend.Mappers
                     contentType = "application/octet-stream";
                 }
 
-                return new FileStreamResult(GetContentStream(filePath), new MediaTypeHeaderValue(contentType)
+                return Task.FromResult<IActionResult>(new FileStreamResult(GetContentStream(filePath), new MediaTypeHeaderValue(contentType)
                 {
                     Encoding = contentType == "text/plain" ? Encoding.UTF8 : null
-                });
+                }));
             }
 
             _logger.Warn("File {0} not found", filePath);