Adding PostProcessingEventHandler Fixes #74

Former-commit-id: f6dcf6a1303211b1123e5b6130d700d0c5699e33

src/ImageProcessor.Web/Helpers/AsyncDeDuperLock.cs → src/ImageProcessor.Web/Helpers/AsyncDuplicateLock.cs

@@ -1,5 +1,5 @@
 // --------------------------------------------------------------------------------------------------------------------
-// <copyright file="AsyncDeDuperLock.cs" company="James South">
+// <copyright file="AsyncDuplicateLock.cs" company="James South">
 //   Copyright (c) James South.
 //   Licensed under the Apache License, Version 2.0.
 // </copyright>
@@ -18,24 +18,24 @@ namespace ImageProcessor.Web.Helpers
     /// Throttles duplicate requests.
     /// Based loosely on <see href="http://stackoverflow.com/a/21011273/427899"/>
     /// </summary>
-    public sealed class AsyncDeDuperLock
+    public sealed class AsyncDuplicateLock
     {
         /// <summary>
-        /// The semaphore slims.
+        /// The collection of semaphore slims.
         /// </summary>
-        private static readonly ConcurrentDictionary<string, SemaphoreSlim> SemaphoreSlims
-                                = new ConcurrentDictionary<string, SemaphoreSlim>();
+        private static readonly ConcurrentDictionary<object, SemaphoreSlim> SemaphoreSlims
+                                = new ConcurrentDictionary<object, SemaphoreSlim>();
 
         /// <summary>
-        /// The lock.
+        /// Locks against the given key.
         /// </summary>
         /// <param name="key">
-        /// The hash.
+        /// The key that identifies the current object.
         /// </param>
         /// <returns>
-        /// The <see cref="IDisposable"/>.
+        /// The disposable <see cref="Task"/>.
         /// </returns>
-        public IDisposable Lock(string key)
+        public IDisposable Lock(object key)
         {
             DisposableScope releaser = new DisposableScope(
             key,
@@ -55,15 +55,15 @@ namespace ImageProcessor.Web.Helpers
         }
 
         /// <summary>
-        /// The lock async.
+        /// Asynchronously locks against the given key.
         /// </summary>
         /// <param name="key">
-        /// The key.
+        /// The key that identifies the current object.
         /// </param>
         /// <returns>
-        /// The <see cref="Task"/>.
+        /// The disposable <see cref="Task"/>.
         /// </returns>
-        public Task<IDisposable> LockAsync(string key)
+        public Task<IDisposable> LockAsync(object key)
         {
             DisposableScope releaser = new DisposableScope(
             key,
@@ -100,12 +100,12 @@ namespace ImageProcessor.Web.Helpers
             /// <summary>
             /// The key
             /// </summary>
-            private readonly string key;
+            private readonly object key;
 
             /// <summary>
             /// The close scope action.
             /// </summary>
-            private readonly Action<string> closeScopeAction;
+            private readonly Action<object> closeScopeAction;
 
             /// <summary>
             /// Initializes a new instance of the <see cref="DisposableScope"/> class.
@@ -116,7 +116,7 @@ namespace ImageProcessor.Web.Helpers
             /// <param name="closeScopeAction">
             /// The close scope action.
             /// </param>
-            public DisposableScope(string key, Action<string> closeScopeAction)
+            public DisposableScope(object key, Action<object> closeScopeAction)
             {
                 this.key = key;
                 this.closeScopeAction = closeScopeAction;

src/ImageProcessor.Web/Helpers/PostProcessingEventArgs.cs

@@ -0,0 +1,25 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="PostProcessingEventArgs.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// <summary>
+//   The post processing event arguments.
+// </summary>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace ImageProcessor.Web.Helpers
+{
+    using System;
+
+    /// <summary>
+    /// The post processing event arguments.
+    /// </summary>
+    public class PostProcessingEventArgs : EventArgs
+    {
+        /// <summary>
+        /// Gets or sets the cached image path.
+        /// </summary>
+        public string CachedImagePath { get; set; }
+    }
+}

src/ImageProcessor.Web/HttpModules/ImageProcessingModule.cs

@@ -62,7 +62,7 @@ namespace ImageProcessor.Web.HttpModules
         /// <summary>
         /// The locker for preventing duplicate requests.
         /// </summary>
-        private static readonly AsyncDeDuperLock Locker = new AsyncDeDuperLock();
+        private static readonly AsyncDuplicateLock Locker = new AsyncDuplicateLock();
 
         /// <summary>
         /// The value to prefix any remote image requests with to ensure they get captured.
@@ -108,6 +108,11 @@ namespace ImageProcessor.Web.HttpModules
         }
         #endregion
 
+        /// <summary>
+        /// The event that is called when a new image is processed.
+        /// </summary>
+        public static event EventHandler<PostProcessingEventArgs> OnPostProcessing;
+
         #region IHttpModule Members
         /// <summary>
         /// Initializes a module and prepares it to handle requests.
@@ -129,12 +134,8 @@ namespace ImageProcessor.Web.HttpModules
                 preserveExifMetaData = ImageProcessorConfiguration.Instance.PreserveExifMetaData;
             }
 
-#if NET45 && !__MonoCS__
             EventHandlerTaskAsyncHelper wrapper = new EventHandlerTaskAsyncHelper(this.PostAuthorizeRequest);
             context.AddOnPostAuthorizeRequestAsync(wrapper.BeginEventHandler, wrapper.EndEventHandler);
-#else
-            context.PostAuthorizeRequest += this.PostAuthorizeRequest;
-#endif
             context.PreSendRequestHeaders += this.ContextPreSendRequestHeaders;
         }
 
@@ -385,6 +386,13 @@ namespace ImageProcessor.Web.HttpModules
                                                     // Trim the cache.
                                                     await cache.TrimCachedFolderAsync(cachedPath);
 
+                                                    // Fire the post processing event.
+                                                    EventHandler<PostProcessingEventArgs> handler = OnPostProcessing;
+                                                    if (handler != null)
+                                                    {
+                                                        handler.Invoke(this, new PostProcessingEventArgs() { CachedImagePath = cachedPath });
+                                                    }
+
                                                     // Store the response type and cache dependency in the context for later retrieval.
                                                     context.Items[CachedResponseTypeKey] = imageFactory.CurrentImageFormat.MimeType;
                                                     context.Items[CachedResponseFileDependency] = new List<string> { cachedPath };
@@ -418,6 +426,13 @@ namespace ImageProcessor.Web.HttpModules
                                     // Trim the cache.
                                     await cache.TrimCachedFolderAsync(cachedPath);
 
+                                    // Fire the post processing event.
+                                    EventHandler<PostProcessingEventArgs> handler = OnPostProcessing;
+                                    if (handler != null)
+                                    {
+                                        handler.Invoke(this, new PostProcessingEventArgs() { CachedImagePath = cachedPath });
+                                    }
+
                                     // Store the response type and cache dependencies in the context for later retrieval.
                                     context.Items[CachedResponseTypeKey] = imageFactory.CurrentImageFormat.MimeType;
                                     context.Items[CachedResponseFileDependency] = new List<string> { requestPath, cachedPath };
@@ -467,7 +482,7 @@ namespace ImageProcessor.Web.HttpModules
             }
             else if (isRemote)
             {
-                // Just repoint to the external url.
+                // Just re-point to the external url.
                 HttpContext.Current.Response.Redirect(requestPath);
             }
         }

src/ImageProcessor.Web/ImageProcessor.Web.csproj

@@ -56,8 +56,9 @@
     <Compile Include="Extensions\DirectoryInfoExtensions.cs" />
     <Compile Include="Extensions\StringExtensions.cs" />
     <Compile Include="Helpers\CommonParameterParserUtility.cs" />
-    <Compile Include="Helpers\AsyncDeDuperLock.cs" />
+    <Compile Include="Helpers\AsyncHighlanderLock.cs" />
     <Compile Include="Helpers\NativeMethods.cs" />
+    <Compile Include="Helpers\PostProcessingEventArgs.cs" />
     <Compile Include="Helpers\ResourceHelpers.cs" />
     <Compile Include="Helpers\ImageHelpers.cs" />
     <Compile Include="Helpers\RemoteFile.cs" />

src/ImageProcessor/Imaging/Formats/JpegFormat.cs

@@ -75,7 +75,7 @@ namespace ImageProcessor.Imaging.Formats
         {
             base.ApplyProcessor(processor, factory);
 
-			// Set the property item information from any Exif metadata.
+            // Set the property item information from any Exif metadata.
             // We do this here so that they can be changed between processor methods.
             if (factory.PreserveExifData)
             {

src/TestWebsites/MVC/Global.asax.cs

@@ -8,6 +8,10 @@ using System.Web.Routing;
 
 namespace Test_Website_NET45
 {
+    using System.Diagnostics;
+
+    using ImageProcessor.Web.HttpModules;
+
     // Note: For instructions on enabling IIS6 or IIS7 classic mode, 
     // visit http://go.microsoft.com/?LinkId=9394801
     public class MvcApplication : System.Web.HttpApplication
@@ -19,6 +23,9 @@ namespace Test_Website_NET45
             WebApiConfig.Register(GlobalConfiguration.Configuration);
             FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
             RouteConfig.RegisterRoutes(RouteTable.Routes);
+
+            // Test the post processing event.
+            ImageProcessingModule.OnPostProcessing += (sender, args) => Debug.WriteLine(args.CachedImagePath);
         }
     }
 }