Use BeginHighlighting()/EndHighlighting() to improve performance of CSharpSemanticHighlighter.

src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpSemanticHighlighter.cs

@@ -7,6 +7,7 @@ using System.Diagnostics;
 using System.Linq;
 using System.Windows.Threading;
 using CSharpBinding.Parser;
+using ICSharpCode.AvalonEdit.Document;
 using ICSharpCode.AvalonEdit.Highlighting;
 using ICSharpCode.AvalonEdit.Rendering;
 using ICSharpCode.Core;
@@ -38,14 +39,17 @@ namespace CSharpBinding
 		readonly HighlightingColor parameterModifierColor;
 		readonly HighlightingColor inactiveCodeColor;
 		
-		List<IDocumentLine> invalidLines = new List<IDocumentLine>();
-		List<CachedLine> cachedLines = new List<CachedLine>();
+		List<IDocumentLine> invalidLines;
+		List<CachedLine> cachedLines;
 		bool hasCrashed;
 		bool forceParseOnNextRefresh;
+		bool eventHandlersAreRegistered;
+		bool inHighlightingGroup;
 		
 		int lineNumber;
 		HighlightedLine line;
 		CSharpAstResolver resolver;
+		CSharpFullParseInformation parseInfo;
 		
 		bool isInAccessor;
 		
@@ -66,14 +70,30 @@ namespace CSharpBinding
 			this.parameterModifierColor = highlighting.GetNamedColor("ParameterModifiers");
 			this.inactiveCodeColor = highlighting.GetNamedColor("InactiveCode");
 			
-			SD.ParserService.ParseInformationUpdated += ParserService_ParseInformationUpdated;
-			SD.ParserService.LoadSolutionProjectsThread.Finished += ParserService_LoadSolutionProjectsThreadEnded;
+			if (document is TextDocument && SD.MainThread.CheckAccess()) {
+				// Use the cache only for the live AvalonEdit document
+				// Highlighting in read-only documents (e.g. search results) does
+				// not need the cache as it does not need to highlight the same line multiple times
+				cachedLines = new List<CachedLine>();
+				// Line invalidation is only necessary for the live AvalonEdit document
+				invalidLines = new List<IDocumentLine>();
+				// Also, attach these event handlers only for real documents in the editor,
+				// we don't need them for the highlighting in search results etc.
+				SD.ParserService.ParseInformationUpdated += ParserService_ParseInformationUpdated;
+				SD.ParserService.LoadSolutionProjectsThread.Finished += ParserService_LoadSolutionProjectsThreadEnded;
+				eventHandlersAreRegistered = true;
+			}
 		}
 		
 		public void Dispose()
 		{
-			SD.ParserService.ParseInformationUpdated -= ParserService_ParseInformationUpdated;
-			SD.ParserService.LoadSolutionProjectsThread.Finished -= ParserService_LoadSolutionProjectsThreadEnded;
+			if (eventHandlersAreRegistered) {
+				SD.ParserService.ParseInformationUpdated -= ParserService_ParseInformationUpdated;
+				SD.ParserService.LoadSolutionProjectsThread.Finished -= ParserService_LoadSolutionProjectsThreadEnded;
+				eventHandlersAreRegistered = false;
+			}
+			this.resolver = null;
+			this.parseInfo = null;
 		}
 		#endregion
 		
@@ -196,34 +216,53 @@ namespace CSharpBinding
 			}
 			ITextSourceVersion newVersion = document.Version;
 			CachedLine cachedLine = null;
-			for (int i = 0; i < cachedLines.Count; i++) {
-				if (cachedLines[i].DocumentLine == documentLine) {
-					if (newVersion == null || !newVersion.BelongsToSameDocumentAs(cachedLines[i].OldVersion)) {
-						// cannot list changes from old to new: we can't update the cache, so we'll remove it
-						cachedLines.RemoveAt(i);
-					} else {
-						cachedLine = cachedLines[i];
+			if (cachedLines != null) {
+				for (int i = 0; i < cachedLines.Count; i++) {
+					if (cachedLines[i].DocumentLine == documentLine) {
+						if (newVersion == null || !newVersion.BelongsToSameDocumentAs(cachedLines[i].OldVersion)) {
+							// cannot list changes from old to new: we can't update the cache, so we'll remove it
+							cachedLines.RemoveAt(i);
+						} else {
+							cachedLine = cachedLines[i];
+						}
+						break;
 					}
-					break;
+				}
+				
+				if (cachedLine != null && cachedLine.IsValid && newVersion.CompareAge(cachedLine.OldVersion) == 0) {
+					// the file hasn't changed since the cache was created, so just reuse the old highlighted line
+					return cachedLine.HighlightedLine;
 				}
 			}
 			
-			if (cachedLine != null && cachedLine.IsValid && newVersion.CompareAge(cachedLine.OldVersion) == 0) {
-				// the file hasn't changed since the cache was created, so just reuse the old highlighted line
-				return cachedLine.HighlightedLine;
+			bool wasInHighlightingGroup = inHighlightingGroup;
+			if (!inHighlightingGroup) {
+				BeginHighlighting();
 			}
-			
-			CSharpFullParseInformation parseInfo;
-			if (forceParseOnNextRefresh) {
-				forceParseOnNextRefresh = false;
-				parseInfo = SD.ParserService.Parse(FileName.Create(document.FileName), document) as CSharpFullParseInformation;
-			} else {
-				parseInfo = SD.ParserService.GetCachedParseInformation(FileName.Create(document.FileName), document.Version) as CSharpFullParseInformation;
+			try {
+				return DoHighlightLine(lineNumber, documentLine, cachedLine, newVersion);
+			} finally {
+				line = null;
+				if (!wasInHighlightingGroup)
+					EndHighlighting();
+			}
+		}
+		
+		HighlightedLine DoHighlightLine(int lineNumber, IDocumentLine documentLine, CachedLine cachedLine, ITextSourceVersion newVersion)
+		{
+			if (parseInfo == null) {
+				if (forceParseOnNextRefresh) {
+					forceParseOnNextRefresh = false;
+					parseInfo = SD.ParserService.Parse(FileName.Create(document.FileName), document) as CSharpFullParseInformation;
+				} else {
+					parseInfo = SD.ParserService.GetCachedParseInformation(FileName.Create(document.FileName), newVersion) as CSharpFullParseInformation;
+				}
 			}
 			if (parseInfo == null) {
-				if (!invalidLines.Contains(documentLine))
+				if (invalidLines != null && !invalidLines.Contains(documentLine)) {
 					invalidLines.Add(documentLine);
-				Debug.WriteLine("Semantic highlighting for line {0} - marking as invalid", lineNumber);
+					Debug.WriteLine("Semantic highlighting for line {0} - marking as invalid", lineNumber);
+				}
 				
 				if (cachedLine != null) {
 					// If there's a cached version, adjust it to the latest document changes and return it.
@@ -235,11 +274,12 @@ namespace CSharpBinding
 				}
 			}
 			
-			var compilation = SD.ParserService.GetCompilationForFile(parseInfo.FileName);
-			this.resolver = parseInfo.GetResolver(compilation);
+			if (resolver == null) {
+				var compilation = SD.ParserService.GetCompilationForFile(parseInfo.FileName);
+				resolver = parseInfo.GetResolver(compilation);
+			}
 			
-			HighlightedLine line = new HighlightedLine(document, documentLine);
-			this.line = line;
+			line = new HighlightedLine(document, documentLine);
 			this.lineNumber = lineNumber;
 			if (Debugger.IsAttached) {
 				parseInfo.SyntaxTree.AcceptVisitor(this);
@@ -251,10 +291,8 @@ namespace CSharpBinding
 					throw new ApplicationException("Error highlighting line " + lineNumber, ex);
 				}
 			}
-			this.line = null;
-			this.resolver = null;
 			//Debug.WriteLine("Semantic highlighting for line {0} - added {1} sections", lineNumber, line.Sections.Count);
-			if (document.Version != null) {
+			if (cachedLines != null && document.Version != null) {
 				cachedLines.Add(new CachedLine(line, document.Version));
 			}
 			return line;
@@ -268,12 +306,22 @@ namespace CSharpBinding
 		
 		public void BeginHighlighting()
 		{
-			
+			if (inHighlightingGroup)
+				throw new InvalidOperationException();
+			inHighlightingGroup = true;
+			if (invalidLines == null) {
+				// if invalidation isn't available, we're forced to parse the file now
+				forceParseOnNextRefresh = true;
+			}
 		}
 		
 		public void EndHighlighting()
 		{
-			// use this event to remove cached lines which are no longer visible
+			inHighlightingGroup = false;
+			this.resolver = null;
+			this.parseInfo = null;
+			
+			// TODO use this to remove cached lines which are no longer visible
 //			var visibleDocumentLines = new HashSet<IDocumentLine>(syntaxHighlighter.GetVisibleDocumentLines());
 //			cachedLines.RemoveAll(c => !visibleDocumentLines.Contains(c.DocumentLine));
 		}

src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/CSharpSymbolSearch.cs

@@ -106,6 +106,8 @@ namespace CSharpBinding
 					if (document == null) {
 						document = new ReadOnlyDocument(textSource, fileName);
 						highlighter = SD.EditorControlService.CreateHighlighter(document);
+						if (highlighter != null)
+							highlighter.BeginHighlighting();
 					}
 					Identifier identifier = node.GetChildByRole(Roles.Identifier);
 					if (!identifier.IsNull)

src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/Parser.cs

@@ -145,6 +145,8 @@ namespace CSharpBinding.Parser
 					if (document == null) {
 						document = new ReadOnlyDocument(fileContent, parseInfo.FileName);
 						highlighter = SD.EditorControlService.CreateHighlighter(document);
+						if (highlighter != null)
+							highlighter.BeginHighlighting();
 					}
 					var region = new DomRegion(parseInfo.FileName, node.StartLocation, node.EndLocation);
 					int offset = document.GetOffset(node.StartLocation);

src/AddIns/BackendBindings/CSharpBinding/Project/Src/Refactoring/SearchForIssuesCommand.cs

@@ -164,6 +164,9 @@ namespace CSharpBinding.Refactoring
 					if (document == null) {
 						document = new ReadOnlyDocument(fileContent, fileName);
 						highlighter = SD.EditorControlService.CreateHighlighter(document);
+						if (highlighter != null) {
+							highlighter.BeginHighlighting();
+						}
 					}
 					results.Add(SearchResultMatch.Create(document, issue.Start, issue.End, highlighter));
 				}
@@ -247,6 +250,8 @@ namespace CSharpBinding.Refactoring
 			}
 			if (allIssues.Count > 0) {
 				using (var highlighter = SD.EditorControlService.CreateHighlighter(document)) {
+					if (highlighter != null)
+						highlighter.BeginHighlighting();
 					return allIssues.Select(issue => SearchResultMatch.Create(document, issue.Start, issue.End, highlighter)).ToList();
 				}
 			} else {

src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlSymbolSearch.cs

@@ -94,6 +94,8 @@ namespace ICSharpCode.XamlBinding
 				if (document == null) {
 					document = new ReadOnlyDocument(textSource, fileName);
 					highlighter = SD.EditorControlService.CreateHighlighter(document);
+					if (highlighter != null)
+						highlighter.BeginHighlighting();
 				}
 				var result = resolver.Resolve(parseInfo, document.GetLocation(offset + entity.Name.Length / 2 + 1), compilation, cancellationToken);
 				int length = entity.Name.Length;

src/AddIns/Misc/SearchAndReplace/Project/Engine/SearchManager.cs

@@ -211,6 +211,8 @@ namespace SearchAndReplace
 					if (document == null) {
 						document = new ReadOnlyDocument(source, fileName);
 						highlighter = SD.EditorControlService.CreateHighlighter(document);
+						if (highlighter != null)
+							highlighter.BeginHighlighting();
 					}
 					var start = document.GetLocation(result.Offset);
 					var end = document.GetLocation(result.Offset + result.Length);

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/DocumentHighlighter.cs

@@ -31,6 +31,8 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		readonly IHighlightingDefinition definition;
 		readonly WeakLineTracker weakLineTracker;
 		bool isHighlighting;
+		bool isInHighlightingGroup;
+		bool isDisposed;
 		
 		/// <summary>
 		/// Gets the document that this DocumentHighlighter is highlighting.
@@ -50,6 +52,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 				throw new ArgumentNullException("definition");
 			this.document = document;
 			this.definition = definition;
+			document.VerifyAccess();
 			weakLineTracker = WeakLineTracker.Register(document, this);
 			InvalidateHighlighting();
 		}
@@ -75,6 +78,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		{
 			if (weakLineTracker != null)
 				weakLineTracker.Deregister();
+			isDisposed = true;
 		}
 		
 		void ILineTracker.BeforeRemoveLine(DocumentLine line)
@@ -197,6 +201,9 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		
 		void CheckIsHighlighting()
 		{
+			if (isDisposed) {
+				throw new ObjectDisposedException("DocumentHighlighter");
+			}
 			if (isHighlighting) {
 				throw new InvalidOperationException("Invalid call - a highlighting operation is currently running.");
 			}
@@ -505,20 +512,28 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		}
 		#endregion
 		
+		/// <inheritdoc/>
 		public HighlightingColor DefaultTextColor {
 			get { return null; }
 		}
 		
+		/// <inheritdoc/>
 		public void BeginHighlighting()
 		{
-			
+			if (isInHighlightingGroup)
+				throw new InvalidOperationException("Highlighting group is already open");
+			isInHighlightingGroup = true;
 		}
 		
+		/// <inheritdoc/>
 		public void EndHighlighting()
 		{
-			
+			if (!isInHighlightingGroup)
+				throw new InvalidOperationException("Highlighting group is not open");
+			isInHighlightingGroup = false;
 		}
 		
+		/// <inheritdoc/>
 		public HighlightingColor GetNamedColor(string name)
 		{
 			return definition.GetNamedColor(name);

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/HighlightingColorizer.cs

@@ -20,6 +20,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		readonly IHighlightingDefinition definition;
 		TextView textView;
 		IHighlighter highlighter;
+		bool isFixedHighlighter;
 		
 		/// <summary>
 		/// Creates a new HighlightingColorizer instance.
@@ -33,7 +34,9 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		}
 		
 		/// <summary>
-		/// Creates a new HighlightingColorizer instance.
+		/// Creates a new HighlightingColorizer instance that uses a fixed highlighter instance.
+		/// The colorizer can only be used with text views that show the document for which
+		/// the highlighter was created.
 		/// </summary>
 		/// <param name="highlighter">The highlighter to be used.</param>
 		public HighlightingColorizer(IHighlighter highlighter)
@@ -41,6 +44,15 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 			if (highlighter == null)
 				throw new ArgumentNullException("highlighter");
 			this.highlighter = highlighter;
+			this.isFixedHighlighter = true;
+		}
+		
+		/// <summary>
+		/// Creates a new HighlightingColorizer instance.
+		/// Derived classes using this constructor must override the <see cref="CreateHighlighter"/> method.
+		/// </summary>
+		protected HighlightingColorizer()
+		{
 		}
 		
 		void textView_DocumentChanged(object sender, EventArgs e)
@@ -61,7 +73,11 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 				// remove highlighter if it is registered
 				if (textView.Services.GetService(typeof(IHighlighter)) == highlighter)
 					textView.Services.RemoveService(typeof(IHighlighter));
-				
+				if (!isFixedHighlighter) {
+					if (highlighter != null)
+						highlighter.Dispose();
+					highlighter = null;
+				}
 			}
 		}
 		
@@ -72,8 +88,9 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		protected virtual void RegisterServices(TextView textView)
 		{
 			if (textView.Document != null) {
-				highlighter = textView.Document != null ? CreateHighlighter(textView, textView.Document) : null;
-				if (highlighter != null) {
+				if (!isFixedHighlighter)
+					highlighter = textView.Document != null ? CreateHighlighter(textView, textView.Document) : null;
+				if (highlighter != null && highlighter.Document == textView.Document) {
 					// add service only if it doesn't already exist
 					if (textView.Services.GetService(typeof(IHighlighter)) == null) {
 						textView.Services.AddService(typeof(IHighlighter), highlighter);
@@ -88,7 +105,10 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		/// </summary>
 		protected virtual IHighlighter CreateHighlighter(TextView textView, TextDocument document)
 		{
-			return highlighter ?? new DocumentHighlighter(document, definition);
+			if (definition != null)
+				return new DocumentHighlighter(document, definition);
+			else
+				throw new NotSupportedException("Cannot create a highlighter because no IHighlightingDefinition was specified, and the CreateHighlighter() method was not overridden.");
 		}
 		
 		/// <inheritdoc/>
@@ -101,6 +121,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 			this.textView = textView;
 			textView.DocumentChanged += textView_DocumentChanged;
 			textView.VisualLineConstructionStarting += textView_VisualLineConstructionStarting;
+			textView.VisualLinesChanged += textView_VisualLinesChanged;
 			RegisterServices(textView);
 		}
 		
@@ -110,6 +131,7 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 			DeregisterServices(textView);
 			textView.DocumentChanged -= textView_DocumentChanged;
 			textView.VisualLineConstructionStarting -= textView_VisualLineConstructionStarting;
+			textView.VisualLinesChanged -= textView_VisualLinesChanged;
 			base.OnRemoveFromTextView(textView);
 			this.textView = null;
 		}
@@ -122,11 +144,19 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 				// We need to detect this case and issue a redraw (through TextViewDocumentHighligher.OnHighlightStateChanged)
 				// before the visual line construction reuses existing lines that were built using the invalid highlighting state.
 				lineNumberBeingColorized = e.FirstLineInView.LineNumber - 1;
+				highlighter.BeginHighlighting();
 				highlighter.UpdateHighlightingState(lineNumberBeingColorized);
 				lineNumberBeingColorized = 0;
 			}
 		}
 		
+		void textView_VisualLinesChanged(object sender, EventArgs e)
+		{
+			if (highlighter != null) {
+				highlighter.EndHighlighting();
+			}
+		}
+		
 		DocumentLine lastColorizedLine;
 		
 		/// <inheritdoc/>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Highlighting/IHighlighter.cs

@@ -63,13 +63,21 @@ namespace ICSharpCode.AvalonEdit.Highlighting
 		event HighlightingStateChangedEventHandler HighlightingStateChanged;
 		
 		/// <summary>
-		/// Opens a group of HighlightLine calls.
+		/// Opens a group of <see cref="HighlightLine"/> calls.
+		/// It is not necessary to call this method before calling <see cref="HighlightLine"/>,
+		/// however, doing so can make the highlighting much more performant in some cases
+		/// (e.g. the C# semantic highlighter in SharpDevelop will re-use the resolver within a highlighting group).
 		/// </summary>
+		/// <remarks>
+		/// The group is closed by either a <see cref="EndHighlighting"/> or a <see cref="IDisposable.Dispose"/> call.
+		/// Nested groups are not allowed.
+		/// </remarks>
 		void BeginHighlighting();
 		
 		/// <summary>
-		/// Closes the currently opened group of HighlightLine calls.
+		/// Closes the currently opened group of <see cref="HighlightLine"/> calls.
 		/// </summary>
+		/// <seealso cref="BeginHighlighting"/>.
 		void EndHighlighting();
 		
 		/// <summary>

src/Main/Base/Project/Src/Services/RefactoringService/FindReferencesAndRenameHelper.cs

@@ -354,6 +354,8 @@ namespace ICSharpCode.SharpDevelop.Refactoring
 					buffer = SD.FileService.GetFileContent(r.FileName);
 					document = new ReadOnlyDocument(buffer, r.FileName);
 					highlighter = SD.EditorControlService.CreateHighlighter(document);
+					if (highlighter != null)
+						highlighter.BeginHighlighting();
 				}
 				var start = r.StartLocation;
 				var end = r.EndLocation;