Tweak FastActivator

Author: cnblogs-dudu

Enyim.Caching/FastActivator.cs

@@ -9,48 +9,54 @@
 
 namespace Enyim.Reflection
 {
-	/// <summary>
-	/// <para>Implements a very fast object factory for dynamic object creation. Dynamically generates a factory class which will use the new() constructor of the requested type.</para>
-	/// <para>Much faster than using Activator at the price of the first invocation being significantly slower than subsequent calls.</para>
-	/// </summary>
-	public static class FastActivator
-	{
-		private static Dictionary<Type, Func<object>> factoryCache = new Dictionary<Type, Func<object>>();
+    /// <summary>
+    /// <para>Implements a very fast object factory for dynamic object creation. Dynamically generates a factory class which will use the new() constructor of the requested type.</para>
+    /// <para>Much faster than using Activator at the price of the first invocation being significantly slower than subsequent calls.</para>
+    /// </summary>
+    public static class FastActivator
+    {
+        private static Dictionary<Type, Func<object>> factoryCache = new Dictionary<Type, Func<object>>();
 
-		/// <summary>
-		/// Creates an instance of the specified type using a generated factory to avoid using Reflection.
-		/// </summary>
-		/// <typeparam name="T">The type to be created.</typeparam>
-		/// <returns>The newly created instance.</returns>
-		public static T Create<T>()
-		{
-			return TypeFactory<T>.Create();
-		}
+        /// <summary>
+        /// Creates an instance of the specified type using a generated factory to avoid using Reflection.
+        /// </summary>
+        /// <typeparam name="T">The type to be created.</typeparam>
+        /// <returns>The newly created instance.</returns>
+        public static T Create<T>()
+        {
+            return TypeFactory<T>.Create();
+        }
 
-		/// <summary>
-		/// Creates an instance of the specified type using a generated factory to avoid using Reflection.
-		/// </summary>
-		/// <param name="type">The type to be created.</param>
-		/// <returns>The newly created instance.</returns>
-		public static object Create(Type type)
-		{
-			Func<object> f;
+        /// <summary>
+        /// Creates an instance of the specified type using a generated factory to avoid using Reflection.
+        /// </summary>
+        /// <param name="type">The type to be created.</param>
+        /// <returns>The newly created instance.</returns>
+        public static object Create(Type type)
+        {
+            Func<object> f;
 
-			if (!factoryCache.TryGetValue(type, out f))
-				lock (factoryCache)
-					if (!factoryCache.TryGetValue(type, out f))
-					{
-						factoryCache[type] = f = Expression.Lambda<Func<object>>(Expression.New(type)).Compile();
-					}
+            if (!factoryCache.TryGetValue(type, out f))
+            {
+                lock (factoryCache)
+                    if (!factoryCache.TryGetValue(type, out f))
+                    {
+                        f = Expression.Lambda<Func<object>>(Expression.New(type)).Compile();
+                        if (f != null)
+                        {
+                            factoryCache[type] = f;
+                        }
+                    }
+            }
 
-			return f();
-		}
+            return f();
+        }
 
-		private static class TypeFactory<T>
-		{
-			public static readonly Func<T> Create = Expression.Lambda<Func<T>>(Expression.New(typeof(T))).Compile();
-		}
-	}
+        private static class TypeFactory<T>
+        {
+            public static readonly Func<T> Create = Expression.Lambda<Func<T>>(Expression.New(typeof(T))).Compile();
+        }
+    }
 }
 
 #region [ License information          ]