[WIP] - NH-2088 - Preliminary work required to generate async code

src/NHibernate/AdoNet/AbstractBatcher.cs

@@ -239,7 +239,7 @@ public virtual DbDataReader ExecuteReader(DbCommand cmd)
 
 			if (!_factory.ConnectionProvider.Driver.SupportsMultipleOpenReaders)
 			{
-				reader = new NHybridDataReader(reader);
+				reader = NHybridDataReader.Create(reader);
 			}
 
 			_readersToClose.Add(reader);

src/NHibernate/AdoNet/ResultSetWrapper.cs

@@ -2,6 +2,8 @@
 using System.Collections;
 using System.Data;
 using System.Data.Common;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace NHibernate.AdoNet
 {
@@ -47,6 +49,21 @@ public override bool Read()
 			return rs.Read();
 		}
 
+		public override Task<bool> ReadAsync(CancellationToken cancellationToken)
+		{
+			return rs.ReadAsync(cancellationToken);
+		}
+
+		public override Task<bool> NextResultAsync(CancellationToken cancellationToken)
+		{
+			return rs.NextResultAsync(cancellationToken);
+		}
+
+		public override Task<bool> IsDBNullAsync(int ordinal, CancellationToken cancellationToken)
+		{
+			return rs.IsDBNullAsync(ordinal, cancellationToken);
+		}
+
 		public override int Depth
 		{
 			get { return rs.Depth; }

src/NHibernate/Collection/AbstractPersistentCollection.cs

@@ -714,7 +714,7 @@ protected virtual ICollection GetOrphans(ICollection oldElements, ICollection cu
 			var currentIds = new HashSet<TypedValue>();
 			foreach (object current in currentElements)
 			{
-				if (current != null && ForeignKeys.IsNotTransient(entityName, current, null, session))
+				if (current != null && ForeignKeys.IsNotTransientSlow(entityName, current, session))
 				{
 					object currentId = ForeignKeys.GetEntityIdentifierIfNotUnsaved(entityName, current, session);
 					currentIds.Add(new TypedValue(idType, currentId));
@@ -736,7 +736,7 @@ protected virtual ICollection GetOrphans(ICollection oldElements, ICollection cu
 
 		public void IdentityRemove(IList list, object obj, string entityName, ISessionImplementor session)
 		{
-			if (obj != null && ForeignKeys.IsNotTransient(entityName, obj, null, session))
+			if (obj != null && ForeignKeys.IsNotTransientSlow(entityName, obj, session))
 			{
 				IType idType = session.Factory.GetEntityPersister(entityName).IdentifierType;
 

src/NHibernate/Criterion/QueryOver.cs

@@ -102,10 +102,30 @@ private IFutureValue<U> FutureValue<U>()
 			return criteria.FutureValue<U>();
 		}
 
-		/// <summary>
-		/// Get an executable instance of <c>IQueryOver&lt;TRoot&gt;</c>,
-		/// to actually run the query.</summary>
-		public IQueryOver<TRoot,TRoot> GetExecutableQueryOver(ISession session)
+		private IAsyncEnumerable<TRoot> FutureAsync()
+		{
+			return criteria.FutureAsync<TRoot>();
+		}
+
+		private IAsyncEnumerable<U> FutureAsync<U>()
+		{
+			return criteria.FutureAsync<U>();
+		}
+
+		private IFutureValueAsync<TRoot> FutureValueAsync()
+		{
+			return criteria.FutureValueAsync<TRoot>();
+		}
+
+		private IFutureValueAsync<U> FutureValueAsync<U>()
+		{
+			return criteria.FutureValueAsync<U>();
+		}
+
+        /// <summary>
+        /// Get an executable instance of <c>IQueryOver&lt;TRoot&gt;</c>,
+        /// to actually run the query.</summary>
+        public IQueryOver<TRoot,TRoot> GetExecutableQueryOver(ISession session)
 		{
 			impl.Session = session.GetSessionImplementation();
 			return new QueryOver<TRoot,TRoot>(impl);
@@ -246,6 +266,18 @@ IFutureValue<TRoot> IQueryOver<TRoot>.FutureValue()
 		IFutureValue<U> IQueryOver<TRoot>.FutureValue<U>()
 		{ return FutureValue<U>(); }
 
+		IAsyncEnumerable<TRoot> IQueryOver<TRoot>.FutureAsync()
+		{ return FutureAsync(); }
+
+		IAsyncEnumerable<U> IQueryOver<TRoot>.FutureAsync<U>()
+		{ return FutureAsync<U>(); }
+
+		IFutureValueAsync<TRoot> IQueryOver<TRoot>.FutureValueAsync()
+		{ return FutureValueAsync(); }
+
+		IFutureValueAsync<U> IQueryOver<TRoot>.FutureValueAsync<U>()
+		{ return FutureValueAsync<U>(); }
+
 		IQueryOver<TRoot,TRoot> IQueryOver<TRoot>.Clone()
 		{ return Clone(); }
 

src/NHibernate/Driver/BasicResultSetsCommand.cs

@@ -7,6 +7,8 @@
 using NHibernate.Engine;
 using NHibernate.SqlCommand;
 using NHibernate.SqlTypes;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace NHibernate.Driver
 {
@@ -53,7 +55,7 @@ public virtual DbDataReader GetReader(int? commandTimeout)
 			}
 			log.Info(command.CommandText);
 			BindParameters(command);
-			return new BatcherDataReaderWrapper(batcher, command);
+			return BatcherDataReaderWrapper.Create(batcher, command);
 		}
 
 		protected virtual void BindParameters(DbCommand command)
@@ -84,9 +86,9 @@ public class BatcherDataReaderWrapper: DbDataReader
 	{
 		private readonly IBatcher batcher;
 		private readonly DbCommand command;
-		private readonly DbDataReader reader;
+		private DbDataReader reader;
 
-		public BatcherDataReaderWrapper(IBatcher batcher, DbCommand command)
+		protected BatcherDataReaderWrapper(IBatcher batcher, DbCommand command)
 		{
 			if (batcher == null)
 			{
@@ -98,7 +100,14 @@ public BatcherDataReaderWrapper(IBatcher batcher, DbCommand command)
 			}
 			this.batcher = batcher;
 			this.command = command;
-			reader = batcher.ExecuteReader(command);
+		}
+
+		public static BatcherDataReaderWrapper Create(IBatcher batcher, DbCommand command)
+		{
+			return new BatcherDataReaderWrapper(batcher, command)
+			{
+				reader = batcher.ExecuteReader(command)
+			};
 		}
 
 		public override string GetName(int i)
@@ -266,6 +275,21 @@ public override bool Read()
 			return reader.Read();
 		}
 
+		public override Task<bool> ReadAsync(CancellationToken cancellationToken)
+		{
+			return reader.ReadAsync(cancellationToken);
+		}
+
+		public override Task<bool> IsDBNullAsync(int ordinal, CancellationToken cancellationToken)
+		{
+			return reader.IsDBNullAsync(ordinal, cancellationToken);
+		}
+
+		public override Task<bool> NextResultAsync(CancellationToken cancellationToken)
+		{
+			return reader.NextResultAsync(cancellationToken);
+		}
+
 		public override int Depth
 		{
 			get { return reader.Depth; }

src/NHibernate/Driver/NDataReader.cs

@@ -4,6 +4,8 @@
 using System.Data;
 using System.Data.Common;
 using NHibernate.Util;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace NHibernate.Driver
 {
@@ -32,6 +34,8 @@ public class NDataReader : DbDataReader
 		private char[] cachedCharArray;
 		private int cachedColIndex = -1;
 
+		protected NDataReader() { }
+
 		/// <summary>
 		/// Creates a NDataReader from a <see cref="DbDataReader" />
 		/// </summary>
@@ -43,8 +47,9 @@ public class NDataReader : DbDataReader
 		/// pick up the <see cref="DbDataReader"/> midstream so that the underlying <see cref="DbDataReader"/> can be closed 
 		/// so a new one can be opened.
 		/// </remarks>
-		public NDataReader(DbDataReader reader, bool isMidstream)
+		public static NDataReader Create(DbDataReader reader, bool isMidstream)
 		{
+			var dataReader = new NDataReader();
 			var resultList = new List<NResult>(2);
 
 			try
@@ -53,19 +58,19 @@ public NDataReader(DbDataReader reader, bool isMidstream)
 				// positioned on the first row (index=0)
 				if (isMidstream)
 				{
-					currentRowIndex = 0;
+					dataReader.currentRowIndex = 0;
 				}
 
 				// there will be atleast one result 
-				resultList.Add(new NResult(reader, isMidstream));
+				resultList.Add(NResult.Create(reader, isMidstream));
 
 				while (reader.NextResult())
 				{
 					// the second, third, nth result is not processed midstream
-					resultList.Add(new NResult(reader, false));
+					resultList.Add(NResult.Create(reader, false));
 				}
 
-				results = resultList.ToArray();
+				dataReader.results = resultList.ToArray();
 			}
 			catch (Exception e)
 			{
@@ -75,6 +80,7 @@ public NDataReader(DbDataReader reader, bool isMidstream)
 			{
 				reader.Close();
 			}
+			return dataReader;
 		}
 
 		/// <summary>
@@ -157,6 +163,21 @@ public override bool Read()
 			return true;
 		}
 
+		public override Task<bool> ReadAsync(CancellationToken cancellationToken)
+		{
+			return Task.FromResult(Read());
+		}
+
+		public override Task<bool> NextResultAsync(CancellationToken cancellationToken)
+		{
+			return Task.FromResult(NextResult());
+		}
+
+		public override Task<bool> IsDBNullAsync(int ordinal, CancellationToken cancellationToken)
+		{
+			return Task.FromResult(IsDBNull(ordinal));
+		}
+
 		/// <summary></summary>
 		public override int Depth
 		{
@@ -463,10 +484,10 @@ public override short GetInt16(int i)
 		private class NResult
 		{
 			// [row][column]
-			private readonly object[][] records;
+			private object[][] records;
 			private int colCount = 0;
 
-			private readonly DataTable schemaTable;
+			private DataTable schemaTable;
 
 			// key = field name
 			// index = field index
@@ -475,6 +496,8 @@ private class NResult
 			private readonly IList<System.Type> fieldTypes = new List<System.Type>();
 			private readonly IList<string> fieldDataTypeNames = new List<string>();
 
+			private NResult() { }
+
 			/// <summary>
 			/// Initializes a new instance of the NResult class.
 			/// </summary>
@@ -483,9 +506,12 @@ private class NResult
 			/// <see langword="true" /> if the <see cref="DbDataReader"/> is already positioned on the record
 			/// to start reading from.
 			/// </param>
-			internal NResult(DbDataReader reader, bool isMidstream)
+			internal static NResult Create(DbDataReader reader, bool isMidstream)
 			{
-				schemaTable = reader.GetSchemaTable();
+				var result = new NResult
+				{
+					schemaTable = reader.GetSchemaTable()
+				};
 
 				List<object[]> recordsList = new List<object[]>();
 				int rowIndex = 0;
@@ -499,13 +525,13 @@ internal NResult(DbDataReader reader, bool isMidstream)
 						for (int i = 0; i < reader.FieldCount; i++)
 						{
 							string fieldName = reader.GetName(i);
-							fieldNameToIndex[fieldName] = i;
-							fieldIndexToName.Add(fieldName);
-							fieldTypes.Add(reader.GetFieldType(i));
-							fieldDataTypeNames.Add(reader.GetDataTypeName(i));
+							result.fieldNameToIndex[fieldName] = i;
+							result.fieldIndexToName.Add(fieldName);
+							result.fieldTypes.Add(reader.GetFieldType(i));
+							result.fieldDataTypeNames.Add(reader.GetDataTypeName(i));
 						}
 
-						colCount = reader.FieldCount;
+						result.colCount = reader.FieldCount;
 					}
 
 					rowIndex++;
@@ -519,7 +545,8 @@ internal NResult(DbDataReader reader, bool isMidstream)
 					isMidstream = false;
 				}
 
-				records = recordsList.ToArray();
+				result.records = recordsList.ToArray();
+				return result;
 			}
 
 			/// <summary>