Improve property injection performance.

bench/Autofac.Benchmarks/Harness.cs

@@ -101,5 +101,8 @@ public void EnumerableResolve()
         {
             BenchmarkRunner.Run<EnumerableResolveBenchmark>();
         }
+
+        [Fact]
+        public void PropertyInjection() => BenchmarkRunner.Run<PropertyInjectionBenchmark>();
     }
 }

bench/Autofac.Benchmarks/PropertyInjectionBenchmark.cs

@@ -0,0 +1,62 @@
+using System;
+using BenchmarkDotNet.Attributes;
+
+namespace Autofac.Benchmarks
+{
+    public class PropertyInjectionBenchmark
+    {
+        private IContainer _container;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            var builder = new ContainerBuilder();
+            builder.RegisterType<A>().PropertiesAutowired();
+            builder.RegisterType<B1>().PropertiesAutowired();
+            builder.RegisterType<B2>().PropertiesAutowired();
+            builder.RegisterType<C1>().PropertiesAutowired();
+            builder.RegisterType<C2>().PropertiesAutowired();
+            builder.RegisterType<D1>();
+            builder.RegisterType<D2>();
+            _container = builder.Build();
+        }
+
+        [Benchmark]
+        public void Resolve()
+        {
+            var instance = _container.Resolve<A>();
+            GC.KeepAlive(instance);
+        }
+
+        internal class A
+        {
+            public B1 B1 { get; set; }
+
+            public B2 B2 { get; set; }
+        }
+
+        internal class B1
+        {
+            public C1 C1 { get; set; }
+        }
+
+        internal class B2
+        {
+            public C2 C2 { get; set; }
+        }
+
+        internal class C1
+        {
+            public D1 D1 { get; set; }
+        }
+
+        internal class C2
+        {
+            public D2 D2 { get; set; }
+        }
+
+        internal class D1 { }
+
+        internal class D2 { }
+    }
+}

src/Autofac/Core/Activators/Reflection/AutowiringPropertyInjector.cs

@@ -24,17 +24,27 @@
 // OTHER DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using Autofac.Util;
 
 namespace Autofac.Core.Activators.Reflection
 {
-    internal class AutowiringPropertyInjector
+    internal static class AutowiringPropertyInjector
     {
         public const string InstanceTypeNamedParameter = "Autofac.AutowiringPropertyInjector.InstanceType";
 
+        private static readonly ConcurrentDictionary<PropertyInfo, Action<object, object>> PropertySetters =
+            new ConcurrentDictionary<PropertyInfo, Action<object, object>>();
+
+        private static readonly ConcurrentDictionary<Type, PropertyInfo[]> InjectableProperties =
+            new ConcurrentDictionary<Type, PropertyInfo[]>();
+
+        private static readonly MethodInfo CallPropertySetterOpenGenericMethod =
+            typeof(AutowiringPropertyInjector).GetTypeInfo().GetDeclaredMethod(nameof(CallPropertySetter));
+
         public static void InjectProperties(IComponentContext context, object instance, IPropertySelector propertySelector, IEnumerable<Parameter> parameters)
         {
             if (context == null)
@@ -57,56 +67,92 @@ public static void InjectProperties(IComponentContext context, object instance,
                 throw new ArgumentNullException(nameof(parameters));
             }
 
+            var resolveParameters = parameters as Parameter[] ?? parameters.ToArray();
+
             var instanceType = instance.GetType();
+            var injectableProperties = InjectableProperties.GetOrAdd(instanceType, type => GetInjectableProperties(type).ToArray());
 
-            foreach (var property in instanceType
-                .GetRuntimeProperties()
-                .Where(pi => pi.CanWrite))
+            for (var index = 0; index < injectableProperties.Length; index++)
             {
-                var propertyType = property.PropertyType;
+                var property = injectableProperties[index];
 
-                if (propertyType.GetTypeInfo().IsValueType && !propertyType.GetTypeInfo().IsEnum)
+                if (!propertySelector.InjectProperty(property, instance))
                 {
                     continue;
                 }
 
-                if (propertyType.IsArray && propertyType.GetElementType().GetTypeInfo().IsValueType)
+                var setParameter = property.SetMethod.GetParameters()[0];
+                var valueProvider = (Func<object>)null;
+                var parameter = resolveParameters.FirstOrDefault(p => p.CanSupplyValue(setParameter, context, out valueProvider));
+                if (parameter != null)
                 {
+                    var setter = PropertySetters.GetOrAdd(property, MakeFastPropertySetter);
+                    setter(instance, valueProvider());
                     continue;
                 }
 
-                if (propertyType.IsGenericEnumerableInterfaceType() && propertyType.GetTypeInfo().GenericTypeArguments[0].GetTypeInfo().IsValueType)
+                var propertyService = new TypedService(property.PropertyType);
+                var instanceTypeParameter = new NamedParameter(InstanceTypeNamedParameter, instanceType);
+                if (context.TryResolveService(propertyService, new Parameter[] { instanceTypeParameter }, out var propertyValue))
+                {
+                    var setter = PropertySetters.GetOrAdd(property, MakeFastPropertySetter);
+                    setter(instance, propertyValue);
+                }
+            }
+        }
+
+        private static IEnumerable<PropertyInfo> GetInjectableProperties(Type instanceType)
+        {
+            foreach (var property in instanceType.GetRuntimeProperties())
+            {
+                if (!property.CanWrite)
                 {
                     continue;
                 }
 
-                if (property.GetIndexParameters().Length != 0)
+                var propertyType = property.PropertyType;
+
+                if (propertyType.GetTypeInfo().IsValueType && !propertyType.GetTypeInfo().IsEnum)
                 {
                     continue;
                 }
 
-                if (!propertySelector.InjectProperty(property, instance))
+                if (propertyType.IsArray && propertyType.GetElementType().GetTypeInfo().IsValueType)
                 {
                     continue;
                 }
 
-                var setParameter = property.SetMethod.GetParameters().First();
-                var valueProvider = (Func<object>)null;
-                var parameter = parameters.FirstOrDefault(p => p.CanSupplyValue(setParameter, context, out valueProvider));
-                if (parameter != null)
+                if (propertyType.IsGenericEnumerableInterfaceType() && propertyType.GetTypeInfo().GenericTypeArguments[0].GetTypeInfo().IsValueType)
                 {
-                    property.SetValue(instance, valueProvider(), null);
                     continue;
                 }
 
-                object propertyValue;
-                var propertyService = new TypedService(propertyType);
-                var instanceTypeParameter = new NamedParameter(InstanceTypeNamedParameter, instanceType);
-                if (context.TryResolveService(propertyService, new Parameter[] { instanceTypeParameter }, out propertyValue))
+                if (property.GetIndexParameters().Length != 0)
                 {
-                    property.SetValue(instance, propertyValue, null);
+                    continue;
                 }
+
+                yield return property;
             }
         }
+
+        private static Action<object, object> MakeFastPropertySetter(PropertyInfo propertyInfo)
+        {
+            var setMethod = propertyInfo.SetMethod;
+            var typeInput = setMethod.DeclaringType;
+            var parameters = setMethod.GetParameters();
+            var parameterType = parameters[0].ParameterType;
+
+            // Create a delegate TDeclaringType -> { TDeclaringType.Property = TValue; }
+            var propertySetterAsAction = setMethod.CreateDelegate(typeof(Action<,>).MakeGenericType(typeInput, parameterType));
+            var callPropertySetterClosedGenericMethod = CallPropertySetterOpenGenericMethod.MakeGenericMethod(typeInput, parameterType);
+            var callPropertySetterDelegate = callPropertySetterClosedGenericMethod.CreateDelegate(typeof(Action<object, object>), propertySetterAsAction);
+
+            return (Action<object, object>)callPropertySetterDelegate;
+        }
+
+        private static void CallPropertySetter<TDeclaringType, TValue>(
+            Action<TDeclaringType, TValue> setter, object target, object value) =>
+                setter((TDeclaringType)target, (TValue)value);
     }
 }