Add in-memory caching to td:// and tdp:// schemes

Browser/Handling/ResourceProvider.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Net;
 using System.Text;
@@ -14,27 +15,9 @@ private static ResourceHandler CreateHandler(byte[] bytes) {
 			return handler;
 		}
 
-		public IResourceHandler Status(HttpStatusCode code, string message) {
+		private static IResourceHandler CreateFileContentsHandler(byte[] bytes, string extension) {
-			var handler = CreateHandler(Encoding.UTF8.GetBytes(message));
-			handler.StatusCode = (int) code;
-			return handler;
-		}
-
-		public IResourceHandler File(string path) {
-			try {
-				return FileContents(System.IO.File.ReadAllBytes(path), Path.GetExtension(path));
-			} catch (FileNotFoundException) {
-				return Status(HttpStatusCode.NotFound, "File not found.");
-			} catch (DirectoryNotFoundException) {
-				return Status(HttpStatusCode.NotFound, "Directory not found.");
-			} catch (Exception e) {
-				return Status(HttpStatusCode.InternalServerError, e.Message);
-			}
-		}
-
-		private IResourceHandler FileContents(byte[] bytes, string extension) {
 			if (bytes.Length == 0) {
-				return Status(HttpStatusCode.NoContent, "File is empty."); // FromByteArray crashes CEF internals with no contents
+				return CreateStatusHandler(HttpStatusCode.NoContent, "File is empty."); // FromByteArray crashes CEF internals with no contents
 			}
 			else {
 				var handler = CreateHandler(bytes);
@@ -42,5 +25,73 @@ private IResourceHandler FileContents(byte[] bytes, string extension) {
 				return handler;
 			}
 		}
+
+		private static IResourceHandler CreateStatusHandler(HttpStatusCode code, string message) {
+			var handler = CreateHandler(Encoding.UTF8.GetBytes(message));
+			handler.StatusCode = (int) code;
+			return handler;
+		}
+
+		private readonly Dictionary<string, ICachedResource> cache = new Dictionary<string, ICachedResource>();
+
+		public IResourceHandler Status(HttpStatusCode code, string message) {
+			return CreateStatusHandler(code, message);
+		}
+
+		public IResourceHandler File(string path) {
+			string key = new Uri(path).LocalPath;
+
+			if (cache.TryGetValue(key, out var cachedResource)) {
+				return cachedResource.GetResource();
+			}
+
+			cachedResource = FileWithCaching(path);
+			cache[key] = cachedResource;
+			return cachedResource.GetResource();
+		}
+
+		private ICachedResource FileWithCaching(string path) {
+			try {
+				return new CachedFile(System.IO.File.ReadAllBytes(path), Path.GetExtension(path));
+			} catch (FileNotFoundException) {
+				return new CachedStatus(HttpStatusCode.NotFound, "File not found.");
+			} catch (DirectoryNotFoundException) {
+				return new CachedStatus(HttpStatusCode.NotFound, "Directory not found.");
+			} catch (Exception e) {
+				return new CachedStatus(HttpStatusCode.InternalServerError, e.Message);
+			}
+		}
+
+		private interface ICachedResource {
+			IResourceHandler GetResource();
+		}
+
+		private sealed class CachedFile : ICachedResource {
+			private readonly byte[] bytes;
+			private readonly string extension;
+
+			public CachedFile(byte[] bytes, string extension) {
+				this.bytes = bytes;
+				this.extension = extension;
+			}
+
+			public IResourceHandler GetResource() {
+				return CreateFileContentsHandler(bytes, extension);
+			}
+		}
+
+		private sealed class CachedStatus : ICachedResource {
+			private readonly HttpStatusCode code;
+			private readonly string message;
+
+			public CachedStatus(HttpStatusCode code, string message) {
+				this.code = code;
+				this.message = message;
+			}
+
+			public IResourceHandler GetResource() {
+				return CreateStatusHandler(code, message);
+			}
+		}
 	}
 }

Plugins/PluginSchemeFactory.cs

@@ -6,7 +6,11 @@ namespace TweetDuck.Plugins {
 	sealed class PluginSchemeFactory : ISchemeHandlerFactory {
 		public const string Name = PluginSchemeHandler<IResourceHandler>.Name;
 
-		private readonly PluginSchemeHandler<IResourceHandler> handler = new PluginSchemeHandler<IResourceHandler>(new ResourceProvider());
+		private readonly PluginSchemeHandler<IResourceHandler> handler;
+
+		public PluginSchemeFactory(ResourceProvider resourceProvider) {
+			handler = new PluginSchemeHandler<IResourceHandler>(resourceProvider);
+		}
 
 		internal void Setup(PluginManager plugins) {
 			handler.Setup(plugins);

Program.cs

@@ -133,8 +133,9 @@ private static void Main() {
 				#endif
 			};
 
-			var resourceScheme = new ResourceSchemeFactory();
+			var resourceProvider = new ResourceProvider();
-			var pluginScheme = new PluginSchemeFactory();
+			var resourceScheme = new ResourceSchemeFactory(resourceProvider);
+			var pluginScheme = new PluginSchemeFactory(resourceProvider);
 
 			settings.SetupCustomScheme(ResourceSchemeFactory.Name, resourceScheme);
 			settings.SetupCustomScheme(PluginSchemeFactory.Name, pluginScheme);

Resources/ResourcesSchemeFactory.cs

@@ -2,7 +2,7 @@
 using System.IO;
 using System.Net;
 using CefSharp;
-using TweetDuck.Browser.Handling;
+using TweetLib.Core.Browser;
 using TweetLib.Core.Utils;
 
 namespace TweetDuck.Resources {
@@ -10,7 +10,12 @@ public class ResourceSchemeFactory : ISchemeHandlerFactory {
 		public const string Name = "td";
 
 		private static readonly string RootPath = Path.Combine(Program.ResourcesPath);
-		private static readonly ResourceProvider ResourceProvider = new ResourceProvider();
+
+		private readonly IResourceProvider<IResourceHandler> resourceProvider;
+
+		public ResourceSchemeFactory(IResourceProvider<IResourceHandler> resourceProvider) {
+			this.resourceProvider = resourceProvider;
+		}
 
 		public IResourceHandler Create(IBrowser browser, IFrame frame, string schemeName, IRequest request) {
 			if (!Uri.TryCreate(request.Url, UriKind.Absolute, out var uri) || uri.Scheme != Name) {
@@ -22,7 +27,7 @@ public IResourceHandler Create(IBrowser browser, IFrame frame, string schemeName
 			}
 
 			string filePath = FileUtils.ResolveRelativePathSafely(RootPath, uri.AbsolutePath.TrimStart('/'));
-			return filePath.Length == 0 ? ResourceProvider.Status(HttpStatusCode.Forbidden, "File path has to be relative to the resources root folder.") : ResourceProvider.File(filePath);
+			return filePath.Length == 0 ? resourceProvider.Status(HttpStatusCode.Forbidden, "File path has to be relative to the resources root folder.") : resourceProvider.File(filePath);
 		}
 	}
 }