Add DBNull support. Issue #70.

yfakariya · yfakariya · commit fe1ad65f61d2 · 2015-05-24T00:48:04.000+09:00
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -261,12 +261,13 @@ Release 0.6.0 Beta2 - 2015/05/24
 
   NEW FEATURE
   * New utility method of SerializationContext to switch back the behavior to previous version's one.
-  * Add corlib only build (MsgPack.Unity3D.Micro). This build only depends mscorlib. This feature is experimental. Related to Issue #72.
+  * Add corlib only build (MsgPack.Unity3D.Micro). This build only depends mscorlib. This feature is experimental. Related to Issue #70.
 
   IMPROVEMENTS
   * Add many workarounds for AOT issues of Mono on iOS (in particular, Unity).
   * System.DateTime, System.DateTimeOffset, System.Runtime.InteropServices.ComTypes.FILETIME are now serialized native representation by default, it keeps 100-nanosecond resolution, DateTimeKind, and Offset.
     You can revert the behavior to the previous Unix Epoc via SerializationContext.DefaultDateTimeConversion or [MessagePackDateTimeMember] custom attribute. Issue #74
+  * System.DBNull become serializable now. Issue #72.
 
   BUG FIXES
   * Fix System.Object instance causes StackOverflowException. Issue #73
diff --git a/Sync.xml b/Sync.xml
@@ -91,6 +91,7 @@
     <Exclude Path="Serialization\DefaultSerializers\System_Collections_Specialized_NameValueCollectionMessagePackSerializer.cs" />
     <Exclude Path="Serialization\DefaultSerializers\System_Collections_QueueMessagePackSerializer.cs" />
     <Exclude Path="Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs" />
+    <Exclude Path="Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs" />
     <Exclude Path="Serialization\Metadata\_IDisposable.cs" />
     <Exclude Path="Serialization\EmittingSerializers\*" />
     <Preserve Path="Serialization\Reflection\ReflectionHelpers.cs" />
diff --git a/src/MsgPack.Net35/MsgPack.Net35.csproj b/src/MsgPack.Net35/MsgPack.Net35.csproj
@@ -410,6 +410,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_ObjectMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_ObjectMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Net40/MsgPack.Net40.csproj b/src/MsgPack.Net40/MsgPack.Net40.csproj
@@ -400,6 +400,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Silverlight.5/MsgPack.Silverlight.5.csproj b/src/MsgPack.Silverlight.5/MsgPack.Silverlight.5.csproj
@@ -388,6 +388,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_Specialized_NameValueCollectionMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_Specialized_NameValueCollectionMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Silverlight.WindowsPhone/MsgPack.Silverlight.WindowsPhone.csproj b/src/MsgPack.Silverlight.WindowsPhone/MsgPack.Silverlight.WindowsPhone.csproj
@@ -439,6 +439,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_Generic_Stack_1MessagePackSerializer`1.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_Generic_Stack_1MessagePackSerializer`1.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Unity3D.Micro/MsgPack.Unity3D.Micro.csproj b/src/MsgPack.Unity3D.Micro/MsgPack.Unity3D.Micro.csproj
@@ -337,6 +337,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Unity3D/MsgPack.Unity3D.csproj b/src/MsgPack.Unity3D/MsgPack.Unity3D.csproj
@@ -350,6 +350,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Unity3D/Serialization/TypedMessagePackSerializerWrapper`1.cs b/src/MsgPack.Unity3D/Serialization/TypedMessagePackSerializerWrapper`1.cs
@@ -57,6 +57,19 @@ protected internal override T UnpackFromCore( Unpacker unpacker )
 			return ( T )this._underlyingSerializer.UnpackFrom( unpacker );
 		}
 
+		protected internal override T UnpackNil()
+		{
+			var asTyped = this._underlyingSerializer as MessagePackSerializer<T>;
+			if ( asTyped != null )
+			{
+				return asTyped.UnpackNil();
+			}
+			else
+			{
+				return base.UnpackNil();
+			}
+		}
+
 		protected internal override void UnpackToCore( Unpacker unpacker, T collection )
 		{
 			this._underlyingSerializer.UnpackTo( unpacker, collection );
diff --git a/src/MsgPack.Xamarin.Android/MsgPack.Xamarin.Android.csproj b/src/MsgPack.Xamarin.Android/MsgPack.Xamarin.Android.csproj
@@ -344,6 +344,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack.Xamarin.iOS/MsgPack.Xamarin.iOS.csproj b/src/MsgPack.Xamarin.iOS/MsgPack.Xamarin.iOS.csproj
@@ -338,6 +338,9 @@
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Collections_StackMessagePackSerializer.cs</Link>
     </Compile>
+    <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs">
+      <Link>Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs</Link>
+    </Compile>
     <Compile Include="..\MsgPack\Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs">
       <Link>Serialization\DefaultSerializers\System_Numerics_ComplexMessagePackSerializer.cs</Link>
     </Compile>
diff --git a/src/MsgPack/MsgPack.csproj b/src/MsgPack/MsgPack.csproj
@@ -197,6 +197,7 @@
     <Compile Include="Serialization\DefaultSerializers\InternalDateTimeExtensions.cs" />
     <Compile Include="Serialization\DefaultSerializers\NativeDateTimeMessagePackSerializer.cs" />
     <Compile Include="Serialization\DefaultSerializers\NativeFileTimeMessagePackSerializer.cs" />
+    <Compile Include="Serialization\DefaultSerializers\System_DBNullMessagePackSerializer.cs" />
     <Compile Include="Serialization\DefaultSerializers\UnixEpocDateTimeMessagePackSerializer.cs" />
     <Compile Include="Serialization\DefaultSerializers\UnixEpocFileTimeMessagePackSerializer.cs" />
     <Compile Include="Serialization\EmittingSerializers\CallbackCollectionMessagePackSerializer`2.cs" />
diff --git a/src/MsgPack/Serialization/DefaultSerializers/System_DBNullMessagePackSerializer.cs b/src/MsgPack/Serialization/DefaultSerializers/System_DBNullMessagePackSerializer.cs
@@ -0,0 +1,57 @@
+﻿#region -- License Terms --
+// 
+// MessagePack for CLI
+// 
+// Copyright (C) 2015 FUJIWARA, Yusuke
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+// 
+#endregion -- License Terms --
+
+#if UNITY_STANDALONE || UNITY_WEBPLAYER || UNITY_WII || UNITY_IPHONE || UNITY_ANDROID || UNITY_PS3 || UNITY_XBOX360 || UNITY_FLASH || UNITY_BKACKBERRY || UNITY_WINRT
+#define UNITY
+#endif
+
+using System;
+#if !UNITY
+using System.Diagnostics.Contracts;
+#endif // !UNITY
+using System.Runtime.Serialization;
+
+namespace MsgPack.Serialization.DefaultSerializers
+{
+	// ReSharper disable once InconsistentNaming
+	internal class System_DBNullMessagePackSerializer : MessagePackSerializer<DBNull>
+	{
+		public System_DBNullMessagePackSerializer( SerializationContext ownerContext )
+			: base( ownerContext ) {}
+
+		protected internal override void PackToCore( Packer packer, DBNull objectTree )
+		{
+			packer.PackNull();
+		}
+
+		protected internal override DBNull UnpackFromCore( Unpacker unpacker )
+		{
+#if DEBUG && !UNITY
+			Contract.Assert( !unpacker.LastReadData.IsNil );
+#endif // DEBUG && !UNITY
+			throw new SerializationException("DBNull value should be nil.");
+		}
+
+		protected internal override DBNull UnpackNil()
+		{
+			return DBNull.Value;
+		}
+	}
+}
diff --git a/src/MsgPack/Serialization/MessagePackSerializer`1.cs b/src/MsgPack/Serialization/MessagePackSerializer`1.cs
@@ -265,20 +265,42 @@ public T UnpackFrom( Unpacker unpacker )
 
 			if ( unpacker.LastReadData.IsNil )
 			{
-				if ( _isNullable )
-				{
-					// null
-					return default( T );
-				}
-				else
-				{
-					throw SerializationExceptions.NewValueTypeCannotBeNull( typeof( T ) );
-				}
+				return this.UnpackNil();
 			}
 
 			return this.UnpackFromCore( unpacker );
 		}
 
+		/// <summary>
+		///		Unpacks the nil value.
+		/// </summary>
+		/// <returns>
+		///		A valid value of <typeparamref name="T"/> which represents 'null' state.
+		/// </returns>
+		/// <remarks>
+		///		<para>
+		///			This method is invoked from <see cref="UnpackFrom"/> method when the current <see cref="Unpacker.LastReadData"/> is <see cref="MessagePackObject.IsNil">nil</see>.
+		///		</para>
+		///		<para>
+		///			The implementation of this class returns <c>null</c> for nullable types (that is, all reference types and <see cref="Nullable{T}"/>); otherwise, throws <see cref="SerializationException"/>.
+		///		</para>
+		///		<para>
+		///			Custom serializers can override this method to provide custom nil representation. For example, built-in <see cref="DBNull"/> serializer overrides this method to return <see cref="DBNull.Value"/> instead of <c>null</c>.
+		///		</para>
+		/// </remarks>
+		protected internal virtual T UnpackNil()
+		{
+			if ( _isNullable )
+			{
+				// null
+				return default( T );
+			}
+			else
+			{
+				throw SerializationExceptions.NewValueTypeCannotBeNull( typeof( T ) );
+			}
+		}
+
 		/// <summary>
 		///		Deserializes object with specified <see cref="Unpacker"/>.
 		/// </summary>
diff --git a/src/MsgPack/Serialization/SerializerRepository.defaults.cs b/src/MsgPack/Serialization/SerializerRepository.defaults.cs
@@ -45,10 +45,12 @@ namespace MsgPack.Serialization
 	// ReSharper disable RedundantNameQualifier
 	partial class SerializerRepository 
 	{
+		internal const int DefaultTableCapacity = 434;
+
 		[System.Diagnostics.CodeAnalysis.SuppressMessage( "Microsoft.Maintainability", "CA1506:AvoidExcessiveClassCoupling", Justification = "This API is naturally coupled with many types" )]
 		internal static Dictionary<RuntimeTypeHandle, object> InitializeDefaultTable( SerializationContext ownerContext )
 		{
-			var dictionary = new Dictionary<RuntimeTypeHandle, object>( 433 );
+			var dictionary = new Dictionary<RuntimeTypeHandle, object>( DefaultTableCapacity );
 			dictionary.Add( typeof( MessagePackObject ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.MsgPack_MessagePackObjectMessagePackSerializer( ownerContext ) );
 			dictionary.Add( typeof( MessagePackObjectDictionary ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.MsgPack_MessagePackObjectDictionaryMessagePackSerializer( ownerContext ) );
 			dictionary.Add( typeof( MessagePackExtendedTypeObject ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.MsgPack_MessagePackExtendedTypeObjectMessagePackSerializer( ownerContext ) );
@@ -76,6 +78,9 @@ internal static Dictionary<RuntimeTypeHandle, object> InitializeDefaultTable( Se
 			dictionary.Add( typeof( System.Collections.Generic.KeyValuePair<,> ).TypeHandle, typeof( System_Collections_Generic_KeyValuePair_2MessagePackSerializer ) );
 			dictionary.Add( typeof( System.ArraySegment<> ).TypeHandle, typeof( System_ArraySegment_1MessagePackSerializer ) );
 #endif // UNITY
+#if !NETFX_CORE
+			dictionary.Add( typeof( DBNull ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.System_DBNullMessagePackSerializer( ownerContext ) );
+#endif // !NETFX_CORE
 			dictionary.Add( typeof( System.Boolean ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.System_BooleanMessagePackSerializer( ownerContext ) );
 			dictionary.Add( typeof( System.Byte ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.System_ByteMessagePackSerializer( ownerContext ) );
 			dictionary.Add( typeof( System.Char ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.System_CharMessagePackSerializer( ownerContext ) );
diff --git a/src/MsgPack/Serialization/SerializerRepository.defaults.tt b/src/MsgPack/Serialization/SerializerRepository.defaults.tt
@@ -250,10 +250,12 @@ namespace MsgPack.Serialization
 	// ReSharper disable RedundantNameQualifier
 	partial class <#= __typeName #> 
 	{
+		internal const int DefaultTableCapacity = <#= __structTypes.Length + __classTypes.Length + __tuples.Length + 10 #>;
+
 		[System.Diagnostics.CodeAnalysis.SuppressMessage( "Microsoft.Maintainability", "CA1506:AvoidExcessiveClassCoupling", Justification = "This API is naturally coupled with many types" )]
 		internal static Dictionary<RuntimeTypeHandle, object> InitializeDefaultTable( SerializationContext ownerContext )
 		{
-			var dictionary = new Dictionary<RuntimeTypeHandle, object>( <#= __structTypes.Length + __classTypes.Length + __tuples.Length + 9 #> );
+			var dictionary = new Dictionary<RuntimeTypeHandle, object>( DefaultTableCapacity );
 			dictionary.Add( typeof( MessagePackObject ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.MsgPack_MessagePackObjectMessagePackSerializer( ownerContext ) );
 			dictionary.Add( typeof( MessagePackObjectDictionary ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.MsgPack_MessagePackObjectDictionaryMessagePackSerializer( ownerContext ) );
 			dictionary.Add( typeof( MessagePackExtendedTypeObject ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.MsgPack_MessagePackExtendedTypeObjectMessagePackSerializer( ownerContext ) );
@@ -281,6 +283,9 @@ namespace MsgPack.Serialization
 			dictionary.Add( typeof( System.Collections.Generic.KeyValuePair<,> ).TypeHandle, typeof( System_Collections_Generic_KeyValuePair_2MessagePackSerializer ) );
 			dictionary.Add( typeof( System.ArraySegment<> ).TypeHandle, typeof( System_ArraySegment_1MessagePackSerializer ) );
 #endif // UNITY
+#if !NETFX_CORE
+			dictionary.Add( typeof( DBNull ).TypeHandle, new MsgPack.Serialization.DefaultSerializers.System_DBNullMessagePackSerializer( ownerContext ) );
+#endif // !NETFX_CORE
 <#
 foreach( Type __type in __structTypes )
 {
diff --git a/test/MsgPack.UnitTest/Serialization/RegressionTests.cs b/test/MsgPack.UnitTest/Serialization/RegressionTests.cs
@@ -18,6 +18,10 @@
 //
 #endregion -- License Terms --
 
+#if UNITY_STANDALONE || UNITY_WEBPLAYER || UNITY_WII || UNITY_IPHONE || UNITY_ANDROID || UNITY_PS3 || UNITY_XBOX360 || UNITY_FLASH || UNITY_BKACKBERRY || UNITY_WINRT
+#define UNITY
+#endif
+
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -37,6 +41,32 @@ namespace MsgPack.Serialization
 	[TestFixture]
 	public class RegressionTests
 	{
+#if !NETFX_CORE
+		[Test]
+		public void TestIssue70()
+		{
+			var serializer = MessagePackSerializer.Get<DBNull>( new SerializationContext() );
+#if !UNITY
+			// Should not be created dynamically.
+			Assert.That( serializer, Is.TypeOf( typeof( DefaultSerializers.System_DBNullMessagePackSerializer ) ) );
+#endif // !UNITY
+
+			using ( var buffer = new MemoryStream() )
+			{
+				serializer.Pack( buffer, DBNull.Value );
+
+				buffer.Position = 0;
+				var packed = Unpacking.UnpackObject( buffer );
+				Assert.That( packed.IsNil, packed.ToString() );
+
+				buffer.Position = 0;
+				var unpacked = serializer.Unpack( buffer );
+				Assert.That( Object.ReferenceEquals( unpacked, null ), Is.False );
+				Assert.That( unpacked, Is.SameAs( DBNull.Value ) );
+			}
+		}
+#endif // !NETFX_CORE
+
 		[Test]
 		public void TestIssue73()
 		{
