Remove memcmp from MessagePackString. Fix #206.

P/Invoke causes verification error in Windows Native.
It gains performance for edge case -- comparing (relatively) large blob (not string).
It is clearly rare, and it may bring packaging issue in future.
In addition, it is not so bad naive managed loop. In best (or worst) case, it only 1.8x slower than memcmp.
Although it is 12x slower when it is well aligned bytes, but it should be rare in real world.

So, memcmp has gone.

Author: yfakariya

CHANGES.txt

@@ -616,6 +616,9 @@ Release 0.9.0 beta1 2016/09/24
 
 Release 0.9.0 (planned)
 
+  BREAKING CHANGES
+  * MessagePackObject comparison which have large binary data will be about 2x - 18x slower in .NET 3.5/4.5/4.6(other platforms will not be affected).
+
   NEW FEATURES
   * Users of serializer code generator API can specify TextWriter to output. This may improve tooling chain.
   * Users of serializer code generator API can suppress [DebuggerNonUserCode] attribute to enable debugger step in.
@@ -629,4 +632,5 @@ Release 0.9.0 (planned)
   * Fix extra field causes IndexOutOfBoundException when reflection based serializers are used. Issue #199
   * Fix some built-in serializers throws InvalidOperationException instead of SerializationException for type errors. Issue #204
   * Fix a combination of readonly members and collection members incorrect code generation when the type also have deserialization constructor. Issue #207.
+  * Fix Windows Native build error. Issue #206.
 

MsgPack.sln

@@ -43,9 +43,6 @@ EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MsgPack.Net45", "src\MsgPack.Net45\MsgPack.Net45.csproj", "{9C7B55A6-AF7F-4D26-AB5B-297B7FF25B6D}"
 EndProject
 Global
-	GlobalSection(Performance) = preSolution
-		HasPerformanceSessions = true
-	EndGlobalSection
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		CodeAnalysis|Any CPU = CodeAnalysis|Any CPU
 		CodeAnalysis|ARM = CodeAnalysis|ARM

src/MsgPack.Net35/MsgPack.Net35.csproj

@@ -1020,9 +1020,6 @@
     <Compile Include="..\MsgPack\UnpackingStreamReader.cs">
       <Link>UnpackingStreamReader.cs</Link>
     </Compile>
-    <Compile Include="..\MsgPack\UnsafeNativeMethods.cs">
-      <Link>UnsafeNativeMethods.cs</Link>
-    </Compile>
     <Compile Include="..\MsgPack\Validation.cs">
       <Link>Validation.cs</Link>
     </Compile>

src/MsgPack.Net45/MsgPack.Net45.csproj

@@ -1057,9 +1057,6 @@
     <Compile Include="..\MsgPack\UnpackingStreamReader.cs">
       <Link>UnpackingStreamReader.cs</Link>
     </Compile>
-    <Compile Include="..\MsgPack\UnsafeNativeMethods.cs">
-      <Link>UnsafeNativeMethods.cs</Link>
-    </Compile>
     <Compile Include="..\MsgPack\Validation.cs">
       <Link>Validation.cs</Link>
     </Compile>

src/MsgPack.Silverlight.5/MsgPack.Silverlight.5.csproj

@@ -56,7 +56,8 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'CodeAnalysis|AnyCPU'">
     <OutputPath>bin\CodeAnalysis\</OutputPath>
     <DefineConstants>TRACE;SILVERLIGHT;CODE_ANALYSIS</DefineConstants>
-    <DocumentationFile></DocumentationFile>
+    <DocumentationFile>
+    </DocumentationFile>
     <Optimize>true</Optimize>
     <NoStdLib>true</NoStdLib>
     <DebugType>pdbonly</DebugType>
@@ -776,9 +777,6 @@
     <Compile Include="..\MsgPack\UnpackingStreamReader.cs">
       <Link>UnpackingStreamReader.cs</Link>
     </Compile>
-    <Compile Include="..\MsgPack\UnsafeNativeMethods.cs">
-      <Link>UnsafeNativeMethods.cs</Link>
-    </Compile>
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Serialization\LockRecursionPolicy.cs" />
     <Compile Include="Serialization\ReaderWriterLockSlim.cs" />

src/MsgPack/MessagePackString.cs

@@ -266,30 +266,21 @@ private static bool EqualsEncoded( MessagePackString left, MessagePackString rig
 				return false;
 			}
 
-#if !UNITY && !WINDOWS_PHONE && !NETFX_CORE
-			if ( _isFastEqualsDisabled == 0 )
-			{
-				try
-				{
-					return UnsafeFastEquals( left._encoded, right._encoded );
-				}
-				catch ( SecurityException )
-				{
-					Interlocked.Exchange( ref _isFastEqualsDisabled, 1 );
-				}
-				catch ( MemberAccessException )
-				{
-					Interlocked.Exchange( ref _isFastEqualsDisabled, 1 );
-				}
-			}
-#endif // if !UNITY && !WINDOWS_PHONE && !NETFX_CORE
-
 			return SlowEquals( left._encoded, right._encoded );
 		}
 
+		// It is 1.8x(not-aligned) - 11.1x (well-aligned) slower than memcmp, but this call is rare and it is acceptable in most cases.
+		// It is roughly equal to String.Equals(String).
 		private static bool SlowEquals( byte[] x, byte[] y )
 		{
-			for ( int i = 0; i < x.Length; i++ )
+			if ( x.Length != y.Length )
+			{
+				return false;
+			}
+
+			// This looks naive, but loop expansion or unsafe code is not effect here (unsafe is more slower).
+
+			for ( var i = 0; i < x.Length; i++ )
 			{
 				if ( x[ i ] != y[ i ] )
 				{
@@ -300,44 +291,6 @@ private static bool SlowEquals( byte[] x, byte[] y )
 			return true;
 		}
 
-#if !UNITY && !WINDOWS_PHONE && !NETFX_CORE
-#if SILVERLIGHT
-		private static int _isFastEqualsDisabled =
-			System.Windows.Application.Current.HasElevatedPermissions ? 0 : 1;
-#else
-		private static int _isFastEqualsDisabled;
-#endif // if SILVERLIGHT
-
-#if DEBUG
-		// for testing
-		internal static bool IsFastEqualsDisabled
-		{
-			get { return _isFastEqualsDisabled != 0; }
-		}
-#endif
-
-#if !NETFX_35 && !UNITY
-		[SecuritySafeCritical]
-#endif // !NETFX_35 && !UNITY
-		private static bool UnsafeFastEquals( byte[] x, byte[] y )
-		{
-#if DEBUG
-			Contract.Assert( x != null, "x != null" );
-			Contract.Assert( y != null, "y != null" );
-			Contract.Assert( 0 < x.Length, "0 < x.Length" );
-			Contract.Assert( x.Length == y.Length, "x.Length == y.Length" );
-#endif // if DEBUG
-			int result;
-			if ( !UnsafeNativeMethods.TryMemCmp( x, y, new UIntPtr( unchecked( ( uint )x.Length ) ), out result ) )
-			{
-				Interlocked.Exchange( ref _isFastEqualsDisabled, 1 );
-				return SlowEquals( x, y );
-			}
-
-			return result == 0;
-		}
-#endif // if !UNITY && !WINDOWS_PHONE && !NETFX_CORE
-
 #if !SILVERLIGHT && !NETSTANDARD1_1 && !NETSTANDARD1_3
 		[Serializable]
 #endif // !SILVERLIGHT && !NETSTANDARD1_1 && !NETSTANDARD1_3

src/MsgPack/MsgPack.csproj

@@ -541,7 +541,6 @@
     <Compile Include="UnpackingMode.cs" />
     <Compile Include="UnpackingStream.cs" />
     <Compile Include="UnpackingStreamReader.cs" />
-    <Compile Include="UnsafeNativeMethods.cs" />
     <Compile Include="Validation.cs" />
     <Compile Include="UnpackingResult.cs" />
     <Compile Include="Unpacker.cs" />