Implemented special interning provider.

3 files changed, 132 insertions, 0 deletions

diff --git a/ICSharpCode.NRefactory.IKVM/FastInterningProvider.cs b/ICSharpCode.NRefactory.IKVM/FastInterningProvider.cs
new file mode 100644
index 00000000..5effc8dd
--- /dev/null
+++ b/ICSharpCode.NRefactory.IKVM/FastInterningProvider.cs
@@ -0,0 +1,130 @@
+// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Runtime.CompilerServices;
+
+using ICSharpCode.NRefactory.Utils;
+
+namespace ICSharpCode.NRefactory.TypeSystem.Implementation
+{
+	/// <summary>
+	/// Fast interning provider. The main difference is that it only supports to intern non frozen objects.
+	/// </summary>
+	sealed class FastInterningProvider : InterningProvider
+	{
+		sealed class ListComparer : IEqualityComparer<IEnumerable>
+		{
+			public bool Equals(IEnumerable a, IEnumerable b)
+			{
+				if (a.GetType() != b.GetType())
+					return false;
+				IEnumerator e1 = a.GetEnumerator();
+				IEnumerator e2 = b.GetEnumerator();
+				while (e1.MoveNext()) {
+					// e1 has more elements than e2; or elements are different
+					if (!e2.MoveNext() || e1.Current != e2.Current)
+						return false;
+				}
+				if (e2.MoveNext()) // e2 has more elements than e1
+					return false;
+				// No need to dispose e1/e2: non-generic IEnumerator doesn't implement IDisposable,
+				// and the underlying enumerator will likely be a List<T>.Enumerator which has an empty Dispose() method.
+				return true;
+			}
+
+			public int GetHashCode(IEnumerable obj)
+			{
+				int hashCode = obj.GetType().GetHashCode();
+				unchecked {
+					foreach (object o in obj) {
+						hashCode *= 27;
+						hashCode += RuntimeHelpers.GetHashCode(o);
+					}
+				}
+				return hashCode;
+			}
+		}
+
+		Dictionary<object, object> byValueDict = new Dictionary<object, object>();
+		Dictionary<int, ISupportsInterning> supportsInternDict = new Dictionary<int, ISupportsInterning>();
+		Dictionary<IEnumerable, IEnumerable> listDict = new Dictionary<IEnumerable, IEnumerable>(new ListComparer());
+
+		public override ISupportsInterning Intern(ISupportsInterning obj)
+		{
+			if (obj == null)
+				return null;
+
+			ISupportsInterning output;
+			var hashCode = obj.GetHashCodeForInterning ();
+			if (supportsInternDict.TryGetValue(hashCode, out output)) {
+				return output;
+			} else {
+				// ensure objects are frozen when we put them into the dictionary
+				// note that Freeze may change the hash code of the object
+				FreezableHelper.Freeze(obj);
+				supportsInternDict.Add (hashCode, obj);
+				return obj;
+			}
+		}
+
+		public override string Intern(string text)
+		{
+			if (text == null)
+				return null;
+
+			object output;
+			if (byValueDict.TryGetValue(text, out output))
+				return (string)output;
+			else
+				return text;
+		}
+
+		public override object InternValue(object obj)
+		{
+			if (obj == null)
+				return null;
+
+			object output;
+			if (byValueDict.TryGetValue(obj, out output))
+				return output;
+			else
+				return obj;
+		}
+
+		public override IList<T> InternList<T>(IList<T> list)
+		{
+			if (list == null)
+				return null;
+			if (list.Count == 0)
+				return EmptyList<T>.Instance;
+			if (!list.IsReadOnly)
+				list = new ReadOnlyCollection<T>(list);
+			IEnumerable output;
+			if (listDict.TryGetValue(list, out output))
+				list = (IList<T>)output;
+			else
+				listDict.Add(list, list);
+			return list;
+		}
+	}
+}
diff --git a/ICSharpCode.NRefactory.IKVM/ICSharpCode.NRefactory.IKVM.csproj b/ICSharpCode.NRefactory.IKVM/ICSharpCode.NRefactory.IKVM.csproj
index 8ef5b98e..ea42305a 100644
--- a/ICSharpCode.NRefactory.IKVM/ICSharpCode.NRefactory.IKVM.csproj
+++ b/ICSharpCode.NRefactory.IKVM/ICSharpCode.NRefactory.IKVM.csproj
@@ -44,6 +44,7 @@
     <Compile Include="IntConstantValue.cs" />

     <Compile Include="StructConstantValue.cs" />

     <Compile Include="ShortConstantValue.cs" />

+    <Compile Include="FastInterningProvider.cs" />

   </ItemGroup>

   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />

   <ItemGroup>

diff --git a/ICSharpCode.NRefactory.IKVM/IkvmLoader.cs b/ICSharpCode.NRefactory.IKVM/IkvmLoader.cs
index 9d73743f..92d5ccf2 100644
--- a/ICSharpCode.NRefactory.IKVM/IkvmLoader.cs
+++ b/ICSharpCode.NRefactory.IKVM/IkvmLoader.cs
@@ -74,6 +74,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// </summary>
 		public IkvmLoader()
 		{
+			interningProvider = new FastInterningProvider ();
 		}
 
 		#region Load Assembly From Disk