Clean-up IObjectsFactory usages (nhibernate#1781)

IObjectsFactory is meant for instantiating NHibernate dependencies, but
it was used in some cases for instantiating value types. Some of its
methods are also hard or impossible to implement with many dependency
injection frameworks.

Follow up to nhibernate#1758

Author: fredericDelaporte

src/NHibernate.Test/Bytecode/ActivatorObjectFactoryFixture.cs

@@ -45,7 +45,7 @@ public void CreateInstanceDefCtor()
 
 
 
-		[Test]
+		[Test, Obsolete]
 		public void CreateInstanceWithNoPublicCtor()
 		{
 			IObjectsFactory of = GetObjectsFactory();
@@ -55,7 +55,7 @@ public void CreateInstanceWithNoPublicCtor()
 			Assert.That(instance, Is.InstanceOf<WithOutPublicParameterLessCtor>());
 		}
 
-		[Test]
+		[Test, Obsolete]
 		public void CreateInstanceOfValueType()
 		{
 			IObjectsFactory of = GetObjectsFactory();
@@ -64,7 +64,7 @@ public void CreateInstanceOfValueType()
 			Assert.That(instance, Is.InstanceOf<ValueType>());
 		}
 
-		[Test]
+		[Test, Obsolete]
 		public void CreateInstanceWithArguments()
 		{
 			IObjectsFactory of = GetObjectsFactory();
@@ -76,4 +76,4 @@ public void CreateInstanceWithArguments()
 			Assert.That(((WithOutPublicParameterLessCtor)instance).Something, Is.EqualTo(value));
 		}
 	}
-}
+}

src/NHibernate.Test/ConnectionTest/CustomCurrentSessionTest.cs

@@ -0,0 +1,55 @@
+using NHibernate.Cfg;
+using NHibernate.Context;
+using NHibernate.Engine;
+using NUnit.Framework;
+
+namespace NHibernate.Test.ConnectionTest
+{
+	[TestFixture]
+	public class CustomCurrentSessionTest : ConnectionManagementTestCase
+	{
+		protected override ISession GetSessionUnderTest()
+		{
+			var session = OpenSession();
+			CustomContext.Session = session;
+			return session;
+		}
+
+		protected override void Configure(Configuration configuration)
+		{
+			base.Configure(cfg);
+			cfg.SetProperty(Environment.CurrentSessionContextClass, typeof(CustomContext).AssemblyQualifiedName);
+		}
+
+		protected override void Release(ISession session)
+		{
+			CustomContext.Session = null;
+			base.Release(session);
+		}
+
+		[Test]
+		public void ContextIsSetup()
+		{
+			Assert.That(Sfi.CurrentSessionContext, Is.InstanceOf<CustomContext>());
+			Assert.That(
+				((CustomContext) Sfi.CurrentSessionContext).Factory,
+				Is.SameAs(((DebugSessionFactory) Sfi).ActualFactory));
+		}
+	}
+
+	public class CustomContext : ISessionFactoryAwareCurrentSessionContext
+	{
+		internal ISessionFactoryImplementor Factory;
+		internal static ISession Session;
+
+		public ISession CurrentSession()
+		{
+			return Session;
+		}
+
+		public void SetFactory(ISessionFactoryImplementor factory)
+		{
+			Factory = factory;
+		}
+	}
+}

src/NHibernate.Test/ConnectionTest/MapBasedSessionContextFixture.cs

@@ -76,4 +76,4 @@ protected override void SetMap(IDictionary value)
 			_map = value;
 		}
 	}
-}
+}

src/NHibernate.Test/ConnectionTest/ThreadLocalCurrentSessionTest.cs

@@ -88,4 +88,4 @@ public static bool HasBind()
 			return context != null && context.ContainsKey(me.factory);
 		}
 	}
-}
+}

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

@@ -187,10 +187,7 @@ private async Task ExecuteInitializedAsync(Action<string> scriptAction, bool exe
 			cancellationToken.ThrowIfCancellationRequested();
 			if (dialect.SupportsSqlBatches)
 			{
-				var objFactory = Environment.ObjectsFactory;
-				ScriptSplitter splitter = (ScriptSplitter)objFactory.CreateInstance(typeof(ScriptSplitter), sql);
-
-				foreach (string stmt in splitter)
+				foreach (var stmt in new ScriptSplitter(sql))
 				{
 					log.Debug("SQL Batch: {0}", stmt);
 					cmd.CommandText = stmt;

src/NHibernate/Bytecode/ActivatorObjectsFactory.cs

@@ -9,14 +9,18 @@ public object CreateInstance(System.Type type)
 			return Activator.CreateInstance(type);
 		}
 
+		// Since v5.2
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public object CreateInstance(System.Type type, bool nonPublic)
 		{
 			return Activator.CreateInstance(type, nonPublic);
 		}
 
+		// Since v5.2
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public object CreateInstance(System.Type type, params object[] ctorArgs)
 		{
 			return Activator.CreateInstance(type, ctorArgs);
 		}
 	}
-}
+}

src/NHibernate/Bytecode/IObjectsFactory.cs

@@ -1,7 +1,9 @@
+using System;
+
 namespace NHibernate.Bytecode
 {
 	/// <summary>
-	/// Interface for instantiate all NHibernate objects.
+	/// Interface for instantiating NHibernate dependencies.
 	/// </summary>
 	public interface IObjectsFactory
 	{
@@ -18,6 +20,8 @@ public interface IObjectsFactory
 		/// <param name="type">The type of object to create.</param>
 		/// <param name="nonPublic">true if a public or nonpublic default constructor can match; false if only a public default constructor can match.</param>
 		/// <returns>A reference to the created object.</returns>
+		// Since v5.2
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		object CreateInstance(System.Type type, bool nonPublic);
 
 		/// <summary>
@@ -27,6 +31,8 @@ public interface IObjectsFactory
 		/// <param name="type">The type of object to create.</param>
 		/// <param name="ctorArgs">An array of constructor arguments.</param>
 		/// <returns>A reference to the created object.</returns>
+		// Since v5.2
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		object CreateInstance(System.Type type, params object[] ctorArgs);
 	}
-}
+}

src/NHibernate/Context/AsyncLocalSessionContext.cs

@@ -30,4 +30,4 @@ protected override ISession Session
 			set => _session.Value = value;
 		}
 	}
-}
+}

src/NHibernate/Context/CurrentSessionContext.cs

@@ -86,4 +86,4 @@ private static CurrentSessionContext GetCurrentSessionContext(ISessionFactory fa
 			return currentSessionContext;
 		}
 	}
-}
+}

src/NHibernate/Context/ICurrentSessionContext.cs

@@ -1,4 +1,4 @@
-using System;
+using NHibernate.Bytecode;
 using NHibernate.Engine;
 
 namespace NHibernate.Context
@@ -12,7 +12,8 @@ namespace NHibernate.Context
 	/// Implementations should adhere to the following:
 	/// <list type="bullet">
 	/// <item><description>contain a constructor accepting a single argument of type
-	/// <see cref="ISessionFactoryImplementor" /></description></item>
+	/// <see cref="ISessionFactoryImplementor" />, or implement
+	/// <see cref="ISessionFactoryAwareCurrentSessionContext"/></description></item>
 	/// <item><description>should be thread safe</description></item>
 	/// <item><description>should be fully serializable</description></item>
 	/// </list>
@@ -42,4 +43,18 @@ public interface ICurrentSessionContext
 		/// locating or creating the current session.</exception>
 		ISession CurrentSession();
 	}
+
+	/// <summary>
+	/// An <see cref="ICurrentSessionContext"/> allowing to set its session factory. Implementing
+	/// this interface allows the <see cref="IObjectsFactory"/> to be used for instantiating the
+	/// session context.
+	/// </summary>
+	public interface ISessionFactoryAwareCurrentSessionContext : ICurrentSessionContext
+	{
+		/// <summary>
+		/// Sets the factory. This method should be called once after creating the context.
+		/// </summary>
+		/// <param name="factory">The factory.</param>
+		void SetFactory(ISessionFactoryImplementor factory);
+	}
 }

src/NHibernate/Context/MapBasedSessionContext.cs

@@ -64,4 +64,4 @@ private ConcurrentDictionary<ISessionFactoryImplementor, ISession> GetConcreteMa
 		/// </summary>
 		protected abstract void SetMap(IDictionary value);
 	}
-}
+}

src/NHibernate/Context/WcfOperationSessionContext.cs

@@ -49,4 +49,4 @@ public class WcfStateExtension : IExtension<OperationContext>
 		public void Attach(OperationContext owner) { }
 		public void Detach(OperationContext owner) { }
 	}
-}
+}

src/NHibernate/Context/WebSessionContext.cs

@@ -25,4 +25,4 @@ protected override void SetMap(IDictionary value)
 			ReflectiveHttpContext.HttpContextCurrentItems[SessionFactoryMapKey] = value;
 		}
 	}
-}
+}

src/NHibernate/Impl/SessionFactoryImpl.cs

@@ -1281,9 +1281,22 @@ private ICurrentSessionContext BuildCurrentSessionContext()
 
 			try
 			{
-				System.Type implClass = ReflectHelper.ClassForName(impl);
-				return
-					(ICurrentSessionContext)Environment.ObjectsFactory.CreateInstance(implClass, new object[] { this });
+				var implClass = ReflectHelper.ClassForName(impl);
+				var constructor = implClass.GetConstructor(new [] { typeof(ISessionFactoryImplementor) });
+				ICurrentSessionContext context;
+				if (constructor != null)
+				{
+					context = (ICurrentSessionContext) constructor.Invoke(new object[] { this });
+				}
+				else
+				{
+					context = (ICurrentSessionContext) Environment.ObjectsFactory.CreateInstance(implClass);
+				}
+				if (context is ISessionFactoryAwareCurrentSessionContext sessionFactoryAwareContext)
+				{
+					sessionFactoryAwareContext.SetFactory(this);
+				}
+				return context;
 			}
 			catch (Exception e)
 			{

src/NHibernate/Tool/hbm2ddl/SchemaExport.cs

@@ -203,10 +203,7 @@ private void ExecuteSql(DbCommand cmd, string sql)
 		{
 			if (dialect.SupportsSqlBatches)
 			{
-				var objFactory = Environment.ObjectsFactory;
-				ScriptSplitter splitter = (ScriptSplitter)objFactory.CreateInstance(typeof(ScriptSplitter), sql);
-
-				foreach (string stmt in splitter)
+				foreach (var stmt in new ScriptSplitter(sql))
 				{
 					log.Debug("SQL Batch: {0}", stmt);
 					cmd.CommandText = stmt;

src/NHibernate/Transform/AliasToBeanResultTransformer.cs

@@ -85,7 +85,7 @@ public override object TransformTuple(object[] tuple, String[] aliases)
 			{
 				result = _resultClass.IsClass
 							? _beanConstructor.Invoke(null)
-							: Cfg.Environment.ObjectsFactory.CreateInstance(_resultClass, true);
+							: Activator.CreateInstance(_resultClass, true);
 
 				for (int i = 0; i < aliases.Length; i++)
 				{

src/NHibernate/Tuple/PocoInstantiator.cs

@@ -103,7 +103,7 @@ private object GetInstance()
 			}
 			if (mappedClass.IsValueType)
 			{
-				return Cfg.Environment.ObjectsFactory.CreateInstance(mappedClass, true);
+				return Activator.CreateInstance(mappedClass, true);
 			}
 			if (constructor == null)
 			{