ICSharpCode.Core: memory optimization: use common XmlNameTable for all addins being loaded.

src/Main/Core/Project/Src/AddInTree/AddIn/AddIn.cs

@@ -227,6 +227,7 @@ namespace ICSharpCode.Core
 							}
 							string fileName = Path.Combine(hintPath, reader.GetAttribute(0));
 							XmlReaderSettings xrs = new XmlReaderSettings();
+							xrs.NameTable = reader.NameTable; // share the name table
 							xrs.ConformanceLevel = ConformanceLevel.Fragment;
 							using (XmlReader includeReader = XmlTextReader.Create(fileName, xrs)) {
 								SetupAddIn(includeReader, addIn, Path.GetDirectoryName(fileName));
@@ -260,16 +261,13 @@ namespace ICSharpCode.Core
 			return paths[pathName];
 		}
 		
-		public static AddIn Load(TextReader textReader)
-		{
-			return Load(textReader, null);
-		}
-		
-		public static AddIn Load(TextReader textReader, string hintPath)
+		public static AddIn Load(TextReader textReader, string hintPath = null, XmlNameTable nameTable = null)
 		{
+			if (nameTable == null)
+				nameTable = new NameTable();
 			try {
 				AddIn addIn = new AddIn();
-				using (XmlTextReader reader = new XmlTextReader(textReader)) {
+				using (XmlTextReader reader = new XmlTextReader(textReader, nameTable)) {
 					while (reader.Read()){
 						if (reader.IsStartElement()) {
 							switch (reader.LocalName) {
@@ -289,14 +287,16 @@ namespace ICSharpCode.Core
 			}
 		}
 		
-		public static AddIn Load(string fileName)
+		public static AddIn Load(string fileName, XmlNameTable nameTable = null)
 		{
 			try {
 				using (TextReader textReader = File.OpenText(fileName)) {
-					AddIn addIn = Load(textReader, Path.GetDirectoryName(fileName));
+					AddIn addIn = Load(textReader, Path.GetDirectoryName(fileName), nameTable);
 					addIn.addInFileName = fileName;
 					return addIn;
 				}
+			} catch (AddInLoadException) {
+				throw;
 			} catch (Exception e) {
 				throw new AddInLoadException("Can't load " + fileName, e);
 			}

src/Main/Core/Project/Src/AddInTree/AddInManager.cs

@@ -260,7 +260,7 @@ namespace ICSharpCode.Core
 		/// </summary>
 		/// <param name="addIns">
 		/// The list of AddIns to add. (use <see cref="AddIn"/> instances
-		/// created by <see cref="AddIn.Load(TextReader)"/>).
+		/// created by <see cref="AddIn.Load(TextReader,string,XmlNameTable)"/>).
 		/// </param>
 		public static void AddExternalAddIns(IList<AddIn> addIns)
 		{

src/Main/Core/Project/Src/AddInTree/AddInTree.cs

@@ -347,10 +347,11 @@ namespace ICSharpCode.Core
 			List<AddIn> list = new List<AddIn>();
 			Dictionary<string, Version> dict = new Dictionary<string, Version>();
 			Dictionary<string, AddIn> addInDict = new Dictionary<string, AddIn>();
+			var nameTable = new System.Xml.NameTable();
 			foreach (string fileName in addInFiles) {
 				AddIn addIn;
 				try {
-					addIn = AddIn.Load(fileName);
+					addIn = AddIn.Load(fileName, nameTable);
 				} catch (AddInLoadException ex) {
 					LoggingService.Error(ex);
 					if (ex.InnerException != null) {

src/Main/Core/Project/Src/Services/PropertyService/Properties.cs

@@ -151,7 +151,11 @@ namespace ICSharpCode.Core
 			if (reader.HasAttributes) {
 				for (int i = 0; i < reader.AttributeCount; i++) {
 					reader.MoveToAttribute(i);
-					properties[reader.Name] = reader.Value;
+					// some values are frequently repeated (e.g. type="MenuItem"),
+					// so we also use the NameTable for attribute values
+					// (XmlReader itself only uses it for attribute names)
+					string val = reader.NameTable.Add(reader.Value);
+					properties[reader.Name] = val;
 				}
 				reader.MoveToElement(); //Moves the reader back to the element node.
 			}