Decouple configuration of IObjectsFactory from BytecodeProvider

src/NHibernate.Test/CfgTest/ConfigurationSchemaFixture.cs

@@ -57,6 +57,30 @@ public void IgnoreSystemOutOfAppConfig()
 			Assert.AreEqual(hc.UseReflectionOptimizer, newhc.UseReflectionOptimizer);
 		}
 
+		[Test]
+		public void ObjectsFactory()
+		{
+			Assume.That(TestsContext.ExecutingWithVsTest, Is.False);
+
+			var xml =
+				@"<?xml version='1.0' encoding='utf-8' ?>
+<hibernate-configuration xmlns='urn:nhibernate-configuration-2.2'>
+		<objects-factory type='test'/>
+		<session-factory>
+		</session-factory>
+</hibernate-configuration>";
+
+			HibernateConfiguration hc;
+			using (var xtr = new XmlTextReader(xml, XmlNodeType.Document, null))
+			{
+				hc = new HibernateConfiguration(xtr);
+				Assert.That(hc.ObjectsFactoryType, Is.Null);
+			}
+
+			hc = HibernateConfiguration.FromAppConfig(xml);
+			Assert.That(hc.ObjectsFactoryType, Is.EqualTo("test"));
+		}
+
 		[Test]
 		public void EmptyFactoryNotAllowed()
 		{

src/NHibernate.Test/CfgTest/CustomObjectsFactoryTest.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Collections.Generic;
+using NHibernate.Bytecode;
+using NUnit.Framework;
+using Environment = NHibernate.Cfg.Environment;
+
+namespace NHibernate.Test.CfgTest
+{
+	[TestFixture]
+	public class CustomObjectsFactoryTest
+	{
+		private class MyObjectsFactory : IObjectsFactory
+		{
+			public object CreateInstance(System.Type type)
+			{
+				throw new NotImplementedException();
+			}
+
+			public object CreateInstance(System.Type type, bool nonPublic)
+			{
+				throw new NotImplementedException();
+			}
+
+			public object CreateInstance(System.Type type, params object[] ctorArgs)
+			{
+				throw new NotImplementedException();
+			}
+		}
+		private class InvalidObjectsFactory
+		{
+		}
+		private class InvalidNoCtorObjectsFactory : MyObjectsFactory
+		{
+			public InvalidNoCtorObjectsFactory(string pizza) {}
+		}
+
+		[Test]
+		public void WhenNoShortCutUsedThenCanBuildObjectsFactory()
+		{
+			var properties = new Dictionary<string, string> { { Environment.PropertyBytecodeProvider, typeof(MyObjectsFactory).AssemblyQualifiedName } };
+			Assert.That(() => Environment.BuildObjectsFactory(properties), Throws.Nothing);
+		}
+
+		[Test]
+		public void WhenNoShortCutUsedThenCanBuildInstanceOfConfiguredObjectsFactory()
+		{
+			var properties = new Dictionary<string, string> { { Environment.PropertyObjectsFactory, typeof(MyObjectsFactory).AssemblyQualifiedName } };
+			Assert.That(Environment.BuildObjectsFactory(properties), Is.InstanceOf<MyObjectsFactory>());
+		}
+
+		[Test]
+		public void WhenInvalidThenThrow()
+		{
+			var properties = new Dictionary<string, string> { { Environment.PropertyObjectsFactory, typeof(InvalidObjectsFactory).AssemblyQualifiedName } };
+			Assert.That(() => Environment.BuildObjectsFactory(properties), Throws.TypeOf<HibernateObjectsFactoryException>());
+		}
+
+		[Test]
+		public void WhenNoDefaultCtorThenThrow()
+		{
+			var properties = new Dictionary<string, string> { { Environment.PropertyObjectsFactory, typeof(InvalidNoCtorObjectsFactory).AssemblyQualifiedName } };
+			Assert.That(() => Environment.BuildObjectsFactory(properties), Throws.TypeOf<HibernateObjectsFactoryException>()
+																				   .And.InnerException.Message.Contains("constructor was not found"));
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH1547/Fixture.cs

@@ -132,7 +132,7 @@ public partial class DriverForSubstitutedCommand : IDriver
 
 		public DriverForSubstitutedCommand()
 		{
-			_driverImplementation = (IDriver) Cfg.Environment.BytecodeProvider.ObjectsFactory.CreateInstance(DriverClass);
+			_driverImplementation = (IDriver) Cfg.Environment.ObjectsFactory.CreateInstance(DriverClass);
 		}
 
 		DbCommand IDriver.GenerateCommand(CommandType type, SqlString sqlString, SqlType[] parameterTypes)

src/NHibernate.Test/TypesTest/AbstractDateTimeTypeFixture.cs

@@ -533,7 +533,7 @@ public class ClientDriverWithParamsStats : IDriver
 
 		public ClientDriverWithParamsStats()
 		{
-			_driverImplementation = (IDriver) Cfg.Environment.BytecodeProvider.ObjectsFactory.CreateInstance(DriverClass);
+			_driverImplementation = (IDriver) Cfg.Environment.ObjectsFactory.CreateInstance(DriverClass);
 		}
 
 		private static void Inc<T>(T type, IDictionary<T, int> dic)

src/NHibernate/Async/Tool/hbm2ddl/SchemaExport.cs

@@ -187,7 +187,7 @@ private async Task ExecuteInitializedAsync(Action<string> scriptAction, bool exe
 			cancellationToken.ThrowIfCancellationRequested();
 			if (dialect.SupportsSqlBatches)
 			{
-				var objFactory = Environment.BytecodeProvider.ObjectsFactory;
+				var objFactory = Environment.ObjectsFactory;
 				ScriptSplitter splitter = (ScriptSplitter)objFactory.CreateInstance(typeof(ScriptSplitter), sql);
 
 				foreach (string stmt in splitter)

src/NHibernate/Async/Tool/hbm2ddl/SchemaUpdate.cs

@@ -78,7 +78,7 @@ public partial class SchemaUpdate
 						{
 							cfg.SetNamingStrategy(
 								(INamingStrategy)
-								Environment.BytecodeProvider.ObjectsFactory.CreateInstance(ReflectHelper.ClassForName(args[i].Substring(9))));
+								Environment.ObjectsFactory.CreateInstance(ReflectHelper.ClassForName(args[i].Substring(9))));
 						}
 					}
 					else

src/NHibernate/Async/Tool/hbm2ddl/SchemaValidator.cs

@@ -48,7 +48,7 @@ public partial class SchemaValidator
 						{
 							cfg.SetNamingStrategy(
 								(INamingStrategy)
-								Cfg.Environment.BytecodeProvider.ObjectsFactory.CreateInstance(ReflectHelper.ClassForName(args[i].Substring(9))));
+								Cfg.Environment.ObjectsFactory.CreateInstance(ReflectHelper.ClassForName(args[i].Substring(9))));
 						}
 					}
 					else

src/NHibernate/Bytecode/AbstractBytecodeProvider.cs

@@ -6,7 +6,6 @@ namespace NHibernate.Bytecode
 {
 	public abstract class AbstractBytecodeProvider : IBytecodeProvider, IInjectableProxyFactoryFactory, IInjectableCollectionTypeFactoryClass
 	{
-		private readonly IObjectsFactory objectsFactory = new ActivatorObjectsFactory();
 		protected System.Type proxyFactoryFactory;
 		private ICollectionTypeFactory collectionTypeFactory;
 		private System.Type collectionTypeFactoryClass = typeof(Type.DefaultCollectionTypeFactory);
@@ -21,7 +20,7 @@ public virtual IProxyFactoryFactory ProxyFactoryFactory
 				{
 					try
 					{
-						return (IProxyFactoryFactory) ObjectsFactory.CreateInstance(proxyFactoryFactory);
+						return (IProxyFactoryFactory) Cfg.Environment.ObjectsFactory.CreateInstance(proxyFactoryFactory);
 					}
 					catch (Exception e)
 					{
@@ -35,10 +34,9 @@ public virtual IProxyFactoryFactory ProxyFactoryFactory
 
 		public abstract IReflectionOptimizer GetReflectionOptimizer(System.Type clazz, IGetter[] getters, ISetter[] setters);
 
-		public virtual IObjectsFactory ObjectsFactory
-		{
-			get { return objectsFactory; }
-		}
+		// Since 5.2
+		[Obsolete("Please use NHibernate.Cfg.Environment.ObjectsFactory instead")]
+		public virtual IObjectsFactory ObjectsFactory => Cfg.Environment.ObjectsFactory;
 
 		public virtual ICollectionTypeFactory CollectionTypeFactory
 		{
@@ -49,7 +47,7 @@ public virtual ICollectionTypeFactory CollectionTypeFactory
 					try
 					{
 						collectionTypeFactory =
-							(ICollectionTypeFactory) ObjectsFactory.CreateInstance(collectionTypeFactoryClass);
+							(ICollectionTypeFactory) Cfg.Environment.ObjectsFactory.CreateInstance(collectionTypeFactoryClass);
 					}
 					catch (Exception e)
 					{

src/NHibernate/Bytecode/HibernateObjectsFactoryException.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace NHibernate.Bytecode
+{
+	/// <summary>
+	/// Thrown if NHibernate can't instantiate the <see cref="IObjectsFactory"/> type.
+	/// </summary>
+	[Serializable]
+	public class HibernateObjectsFactoryException : HibernateException
+	{
+		public HibernateObjectsFactoryException() {}
+		public HibernateObjectsFactoryException(string message) : base(message) {}
+		public HibernateObjectsFactoryException(string message, Exception inner) : base(message, inner) {}
+
+		protected HibernateObjectsFactoryException(SerializationInfo info, StreamingContext context) : base(info, context) {}
+	}
+}

src/NHibernate/Bytecode/IBytecodeProvider.cs

@@ -1,3 +1,4 @@
+using System;
 using NHibernate.Properties;
 
 namespace NHibernate.Bytecode
@@ -26,6 +27,8 @@ public interface IBytecodeProvider
 		/// <remarks>
 		/// For entities <see cref="IReflectionOptimizer"/> and its implementations.
 		/// </remarks>
+		// Since 5.2
+		[Obsolete("Please use NHibernate.Cfg.Environment.ObjectsFactory instead")]
 		IObjectsFactory ObjectsFactory { get; }
 
 		/// <summary>

src/NHibernate/Cfg/Configuration.cs

@@ -1902,7 +1902,7 @@ public void SetListeners(ListenerType type, string[] listenerClasses)
 				{
 					try
 					{
-						listeners[i] = Environment.BytecodeProvider.ObjectsFactory.CreateInstance(ReflectHelper.ClassForName(listenerClasses[i]));
+						listeners[i] = Environment.ObjectsFactory.CreateInstance(ReflectHelper.ClassForName(listenerClasses[i]));
 					}
 					catch (Exception e)
 					{

src/NHibernate/Cfg/ConfigurationSchema/CfgXmlHelper.cs

@@ -35,6 +35,7 @@ static CfgXmlHelper()
 			nsMgr.AddNamespace(CfgNamespacePrefix, CfgSchemaXMLNS);
 
 			ByteCodeProviderExpression = XPathExpression.Compile(RootPrefixPath + "bytecode-provider", nsMgr);
+			ObjectsFactoryExpression = XPathExpression.Compile(RootPrefixPath + "objects-factory", nsMgr);
 			ReflectionOptimizerExpression = XPathExpression.Compile(RootPrefixPath + "reflection-optimizer", nsMgr);
 			SessionFactoryExpression = XPathExpression.Compile(RootPrefixPath + "session-factory", nsMgr);
 			SessionFactoryPropertiesExpression = XPathExpression.Compile(RootPrefixPath + "session-factory/" + ChildPrefixPath + "property", nsMgr);
@@ -47,6 +48,8 @@ static CfgXmlHelper()
 
 		/// <summary>XPath expression for bytecode-provider property.</summary>
 		public static readonly XPathExpression ByteCodeProviderExpression;
+		/// <summary>XPath expression for objects-factory property.</summary>
+		public static readonly XPathExpression ObjectsFactoryExpression;
 		/// <summary>XPath expression for reflection-optimizer property.</summary>
 		public static readonly XPathExpression ReflectionOptimizerExpression;
 		/// <summary>XPath expression for session-factory whole node.</summary>

src/NHibernate/Cfg/ConfigurationSchema/HibernateConfiguration.cs

@@ -77,6 +77,7 @@ private XmlReaderSettings GetSettings()
 		private void Parse(XPathNavigator navigator, bool fromAppConfig)
 		{
 			ParseByteCodeProvider(navigator, fromAppConfig);
+			ParseObjectsFactory(navigator, fromAppConfig);
 			ParseReflectionOptimizer(navigator, fromAppConfig);
 			XPathNavigator xpn = navigator.SelectSingleNode(CfgXmlHelper.SessionFactoryExpression);
 			if (xpn != null)
@@ -110,6 +111,23 @@ private void ParseByteCodeProvider(XPathNavigator navigator, bool fromAppConfig)
 			}
 		}
 
+		private void ParseObjectsFactory(XPathNavigator navigator, bool fromAppConfig)
+		{
+			var xpn = navigator.SelectSingleNode(CfgXmlHelper.ObjectsFactoryExpression);
+			if (xpn != null)
+			{
+				if (fromAppConfig)
+				{
+					xpn.MoveToFirstAttribute();
+					ObjectsFactoryType = xpn.Value;
+				}
+				else
+				{
+					LogWarnIgnoredProperty("objects-factory");
+				}
+			}
+		}
+
 		private static void LogWarnIgnoredProperty(string propName)
 		{
 			if (log.IsWarnEnabled())
@@ -143,6 +161,13 @@ public string ByteCodeProviderType
 			get { return byteCodeProviderType; }
 		}
 
+		/// <summary>
+		/// Value for objects-factory system property.
+		/// </summary>
+		/// <remarks>Default value <see langword="null" />.</remarks>
+		// 6.0 TODO add to IHibernateConfiguration
+		public string ObjectsFactoryType { get; private set; }
+
 		private bool useReflectionOptimizer = true;
 		/// <summary>
 		/// Value for reflection-optimizer system property.

src/NHibernate/Cfg/Environment.cs

@@ -201,6 +201,11 @@ public static string Version
 		public const string PropertyBytecodeProvider = "bytecode.provider";
 		public const string PropertyUseReflectionOptimizer = "use_reflection_optimizer";
 
+		/// <summary>
+		/// Set the <see cref="IObjectsFactory"/> used to instantiate NHibernate's objects.
+		/// </summary>
+		public const string PropertyObjectsFactory = "objects_factory";
+
 		public const string UseProxyValidator = "use_proxy_validator";
 		public const string ProxyFactoryFactoryClass = "proxyfactory.factory_class";
 
@@ -306,6 +311,10 @@ public static void InitializeGlobalProperties(IHibernateConfiguration config)
 				HibernateConfiguration = config;
 				GlobalProperties[PropertyBytecodeProvider] = config.ByteCodeProviderType;
 				GlobalProperties[PropertyUseReflectionOptimizer] = config.UseReflectionOptimizer.ToString();
+				if (config is HibernateConfiguration nhConfig)
+				{
+					GlobalProperties[PropertyObjectsFactory] = nhConfig.ObjectsFactoryType;
+				}
 				if (config.SessionFactory != null)
 				{
 					foreach (var kvp in config.SessionFactory.Properties)
@@ -322,6 +331,7 @@ public static void InitializeGlobalProperties(IHibernateConfiguration config)
 			VerifyProperties(GlobalProperties);
 
 			BytecodeProviderInstance = BuildBytecodeProvider(GlobalProperties);
+			ObjectsFactory = BuildObjectsFactory(GlobalProperties);
 			EnableReflectionOptimizer = PropertiesHelper.GetBoolean(PropertyUseReflectionOptimizer, GlobalProperties);
 
 			if (EnableReflectionOptimizer)
@@ -381,6 +391,16 @@ public static IBytecodeProvider BytecodeProvider
 			set { BytecodeProviderInstance = value; }
 		}
 
+		/// <summary>
+		/// NHibernate's object instantiator.
+		/// </summary>
+		/// <remarks>
+		/// This should only be set before a configuration object
+		/// is created, otherwise the change may not take effect.
+		/// For entities see <see cref="IReflectionOptimizer"/> and its implementations.
+		/// </remarks>
+		public static IObjectsFactory ObjectsFactory { get; set; } = new ActivatorObjectsFactory();
+
 		/// <summary>
 		/// Whether to enable the use of reflection optimizer
 		/// </summary>
@@ -420,6 +440,18 @@ private static IBytecodeProvider BuildBytecodeProvider(string providerName)
 			}
 		}
 
+		public static IObjectsFactory BuildObjectsFactory(IDictionary<string, string> properties)
+		{
+			var typeAssemblyQualifiedName = PropertiesHelper.GetString(PropertyObjectsFactory, properties, null);
+			if (typeAssemblyQualifiedName == null)
+			{
+				log.Info("Objects factory class : {0}", typeof(ActivatorObjectsFactory));
+				return new ActivatorObjectsFactory();
+			}
+			log.Info("Custom objects factory class : {0}", typeAssemblyQualifiedName);
+			return CreateCustomObjectsFactory(typeAssemblyQualifiedName);
+		}
+
 		private static IBytecodeProvider CreateCustomBytecodeProvider(string assemblyQualifiedName)
 		{
 			try
@@ -447,5 +479,34 @@ private static IBytecodeProvider CreateCustomBytecodeProvider(string assemblyQua
 				throw new HibernateByteCodeException("Unable to create the instance of Bytecode provider; check inner exception for detail", e);
 			}
 		}
+
+		private static IObjectsFactory CreateCustomObjectsFactory(string assemblyQualifiedName)
+		{
+			try
+			{
+				var type = ReflectHelper.ClassForName(assemblyQualifiedName);
+				try
+				{
+					return (IObjectsFactory) Activator.CreateInstance(type);
+				}
+				catch (MissingMethodException ex)
+				{
+					throw new HibernateObjectsFactoryException("Public constructor was not found for " + type, ex);
+				}
+				catch (InvalidCastException ex)
+				{
+					throw new HibernateObjectsFactoryException(type + "Type does not implement " + typeof(IObjectsFactory), ex);
+				}
+				catch (Exception ex)
+				{
+					throw new HibernateObjectsFactoryException("Unable to instantiate: " + type, ex);
+				}
+			}
+			catch (Exception e)
+			{
+				throw new HibernateObjectsFactoryException("Unable to create the instance of objects factory; check inner exception for detail", e);
+			}
+		}
+
 	}
 }