Refactored custom data readers to be created and initialized within a factory method in order to ensure that the instance will always be fully initialized.

Author: maca88

src/NHibernate/AdoNet/AbstractBatcher.cs

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

src/NHibernate/Driver/BasicResultSetsCommand.cs

@@ -53,7 +53,7 @@ public virtual DbDataReader GetReader(int? commandTimeout)
 			}
 			log.Info(command.CommandText);
 			BindParameters(command);
-			return new BatcherDataReaderWrapper(batcher, command).Initialize();
+			return BatcherDataReaderWrapper.Create(batcher, command);
 		}
 
 		protected virtual void BindParameters(DbCommand command)
@@ -86,7 +86,7 @@ public class BatcherDataReaderWrapper: DbDataReader
 		private readonly DbCommand command;
 		private DbDataReader reader;
 
-		public BatcherDataReaderWrapper(IBatcher batcher, DbCommand command)
+		protected BatcherDataReaderWrapper(IBatcher batcher, DbCommand command)
 		{
 			if (batcher == null)
 			{
@@ -100,10 +100,12 @@ public BatcherDataReaderWrapper(IBatcher batcher, DbCommand command)
 			this.command = command;
 		}
 
-		public BatcherDataReaderWrapper Initialize()
+		public static BatcherDataReaderWrapper Create(IBatcher batcher, DbCommand command)
 		{
-			reader = batcher.ExecuteReader(command);
-			return this;
+			return new BatcherDataReaderWrapper(batcher, command)
+			{
+				reader = batcher.ExecuteReader(command)
+			};
 		}
 
 		public override string GetName(int i)

src/NHibernate/Driver/NDataReader.cs

@@ -32,6 +32,8 @@ 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 +45,9 @@ 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 Initialize(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 +56,19 @@ public NDataReader Initialize(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().Initialize(reader, isMidstream));
+				resultList.Add(NResult.Create(reader, isMidstream));
 
 				while (reader.NextResult())
 				{
 					// the second, third, nth result is not processed midstream
-					resultList.Add(new NResult().Initialize(reader, false));
+					resultList.Add(NResult.Create(reader, false));
 				}
 
-				results = resultList.ToArray();
+				dataReader.results = resultList.ToArray();
 			}
 			catch (Exception e)
 			{
@@ -75,7 +78,7 @@ public NDataReader Initialize(DbDataReader reader, bool isMidstream)
 			{
 				reader.Close();
 			}
-			return this;
+			return dataReader;
 		}
 
 		/// <summary>
@@ -476,6 +479,8 @@ 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>
@@ -484,9 +489,12 @@ private class NResult
 			/// <see langword="true" /> if the <see cref="DbDataReader"/> is already positioned on the record
 			/// to start reading from.
 			/// </param>
-			internal NResult Initialize(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;
@@ -500,13 +508,13 @@ internal NResult Initialize(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++;
@@ -520,8 +528,8 @@ internal NResult Initialize(DbDataReader reader, bool isMidstream)
 					isMidstream = false;
 				}
 
-				records = recordsList.ToArray();
-				return this;
+				result.records = recordsList.ToArray();
+				return result;
 			}
 
 			/// <summary>

src/NHibernate/Driver/NHybridDataReader.cs

@@ -30,31 +30,34 @@ public class NHybridDataReader : DbDataReader
 
 		public DbDataReader Target { get { return _reader; } }
 
+		protected NHybridDataReader() { }
+
 		/// <summary>
 		/// Initializes a new instance of the <see cref="NHybridDataReader"/> class.
 		/// </summary>
 		/// <param name="reader">The underlying DbDataReader to use.</param>
-		public NHybridDataReader Initialize(DbDataReader reader)
+		public static NHybridDataReader Create(DbDataReader reader)
 		{
-			return Initialize(reader, false);
+			return Create(reader, false);
 		}
 
 		/// <summary>
 		/// Initializes a new instance of the NHybridDataReader class.
 		/// </summary>
 		/// <param name="reader">The underlying DbDataReader to use.</param>
 		/// <param name="inMemory"><see langword="true" /> if the contents of the DbDataReader should be read into memory right away.</param>
-		public NHybridDataReader Initialize(DbDataReader reader, bool inMemory)
+		public static NHybridDataReader Create(DbDataReader reader, bool inMemory)
 		{
+			var dataReader = new NHybridDataReader();
 			if (inMemory)
 			{
-				_reader = new NDataReader().Initialize(reader, false);
+				dataReader._reader = NDataReader.Create(reader, false);
 			}
 			else
 			{
-				_reader = reader;
+				dataReader._reader = reader;
 			}
-			return this;
+			return dataReader;
 		}
 
 		/// <summary>
@@ -72,7 +75,7 @@ public void ReadIntoMemory()
 				{
 					log.Debug("Moving DbDataReader into an NDataReader.  It was converted in midstream " + _isMidstream.ToString());
 				}
-				_reader = new NDataReader().Initialize(_reader, _isMidstream);
+				_reader = NDataReader.Create(_reader, _isMidstream);
 			}
 		}