Adds response cache.

This gives the provider a much needed performance boost.

Author: JimBobSquarePants

src/UmbracoFileSystemProviders.Azure/AzureFileSystem.cs

@@ -57,11 +57,6 @@ internal class AzureFileSystem : IFileSystem
         /// </summary>
         private readonly string containerName;
 
-        /// <summary>
-        /// The maximum number of days to cache blob items for in the browser.
-        /// </summary>
-        private readonly int maxDays;
-
         /// <summary>
         /// The root url.
         /// </summary>
@@ -118,7 +113,7 @@ private AzureFileSystem(string containerName, string rootUrl, string connectionS
 
             this.rootUrl = rootUrl + containerName + "/";
             this.containerName = containerName;
-            this.maxDays = maxDays;
+            this.MaxDays = maxDays;
 
             this.LogHelper = new WrappedLogHelper();
             this.MimeTypeResolver = new MimeTypeResolver();
@@ -139,6 +134,11 @@ private AzureFileSystem(string containerName, string rootUrl, string connectionS
         /// </summary>
         public bool DisableVirtualPathProvider { get; set; }
 
+        /// <summary>
+        /// Gets or sets the maximum number of days to cache blob items for in the browser.
+        /// </summary>
+        public int MaxDays { get; set; }
+
         /// <summary>
         /// Returns a singleton instance of the <see cref="AzureFileSystem"/> class.
         /// </summary>
@@ -207,7 +207,7 @@ public void AddFile(string path, Stream stream, bool overrideIfExists)
                     blockBlob.Properties.ContentType = contentType;
                 }
 
-                blockBlob.Properties.CacheControl = string.Format("public, max-age={0}", this.maxDays * 86400);
+                blockBlob.Properties.CacheControl = string.Format("public, max-age={0}", this.MaxDays * 86400);
                 blockBlob.SetProperties();
 
                 if (created == DateTimeOffset.MinValue)

src/UmbracoFileSystemProviders.Azure/FileSystemVirtualFile.cs

@@ -12,8 +12,11 @@ namespace Our.Umbraco.FileSystemProviders.Azure
 {
     using System;
     using System.IO;
+    using System.Web;
     using System.Web.Hosting;
 
+    using global::Umbraco.Core.IO;
+
     /// <summary>
     /// Represents a file object in a virtual file.
     /// </summary>
@@ -27,24 +30,21 @@ internal class FileSystemVirtualFile : VirtualFile
         /// <summary>
         /// Initializes a new instance of the <see cref="FileSystemVirtualFile"/> class.
         /// </summary>
-        /// <param name="virtualPath">
-        /// The virtual path.
-        /// </param>
-        /// <param name="stream">
-        /// The stream.
-        /// </param>
+        /// <param name="virtualPath">The virtual path.</param>
+        /// <param name="fileSystem">The lazy file system implementation.</param>
+        /// <param name="fileSystemPath">The modified file system path.</param>
         /// <exception cref="ArgumentNullException">
-        /// Thrown if <paramref name="stream"/> is null.
+        /// Thrown if <paramref name="fileSystem"/> is null.
         /// </exception>
-        public FileSystemVirtualFile(string virtualPath, Func<Stream> stream)
+        public FileSystemVirtualFile(string virtualPath, Lazy<IFileSystem> fileSystem, string fileSystemPath)
             : base(virtualPath)
         {
-            if (stream == null)
+            if (fileSystem == null)
             {
-                throw new ArgumentNullException("stream");
+                throw new ArgumentNullException("fileSystem");
             }
 
-            this.stream = stream;
+            this.stream = () => fileSystem.Value.OpenFile(fileSystemPath);
         }
 
         /// <summary>
@@ -66,6 +66,18 @@ public override bool IsDirectory
         /// </returns>
         public override Stream Open()
         {
+            // Set the response headers here. It's a bit hacky.
+            HttpCachePolicy cache = HttpContext.Current.Response.Cache;
+            cache.SetCacheability(HttpCacheability.Public);
+            cache.VaryByHeaders["Accept-Encoding"] = true;
+
+            IFileSystem azureBlobFileSystem = FileSystemProviderManager.Current.GetUnderlyingFileSystemProvider("media");
+            int maxDays = ((AzureBlobFileSystem)azureBlobFileSystem).FileSystem.MaxDays;
+
+            cache.SetExpires(DateTime.Now.ToUniversalTime().AddDays(maxDays));
+            cache.SetMaxAge(new TimeSpan(maxDays, 0, 0, 0));
+            cache.SetRevalidation(HttpCacheRevalidation.AllCaches);
+
             return this.stream();
         }
     }

src/UmbracoFileSystemProviders.Azure/FileSystemVirtualPathProvider.cs

@@ -142,9 +142,10 @@ public override VirtualFile GetFile(string virtualPath)
             }
 
             string fileSystemPath = this.RemovePathPrefix(path);
-            return new FileSystemVirtualFile(virtualPath, () => this.fileSystem.Value.OpenFile(fileSystemPath));
-        }
 
+            return new FileSystemVirtualFile(virtualPath, this.fileSystem, fileSystemPath);
+        }
+        
         /// <summary>
         /// Correctly formats the virtual path prefix.
         /// </summary>

src/UmbracoFileSystemProviders.Azure/app.config

@@ -12,4 +12,10 @@
       </dependentAssembly>
     </assemblyBinding>
   </runtime>
+  <appSettings>
+    <!--
+      Enables the development mode for testing. Addition changes to the FileSystemProviders.config are also required
+    -->
+    <add key="AzureBlobFileSystem.UseStorageEmulator" value="true" />
+  </appSettings>
 </configuration>