Added an Expression cache

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@2876 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/Misc/Debugger/Debugger.AddIn/Project/Src/Pads/LocalVarPad.cs

@@ -221,6 +221,7 @@ namespace ICSharpCode.SharpDevelop.Gui.Pads
 		
 		public override void RefreshPad()
 		{
+			Debugger.AddIn.TreeModel.Util.ResetDoEventsStartTime();
 			DateTime start = Debugger.Util.HighPrecisionTimer.Now;
 			try {
 				if (debuggedProcess != null && debuggedProcess.SelectedStackFrame != null) {

src/AddIns/Misc/Debugger/Debugger.AddIn/Project/Src/TreeModel/Util.cs

@@ -22,6 +22,11 @@ namespace Debugger.AddIn.TreeModel
 		const double maxFPS      = 30;   // this prevents too much drawing on good machine
 		const double maxWorkTime = 250;  // ms  this ensures minimal response on bad machine
 		
+		public static void ResetDoEventsStartTime()
+		{
+			nextDoEventsTime = Debugger.Util.HighPrecisionTimer.Now.AddMilliseconds(1000 / maxFPS);
+		}
+		
 		public static void DoEvents()
 		{
 			if (Debugger.Util.HighPrecisionTimer.Now > nextDoEventsTime) {

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Expressions/Ast/ThisReferenceExpression.cs

@@ -34,7 +34,7 @@ namespace Debugger.Expressions
 		
 		public override bool Equals(object obj)
 		{
-			return obj is EmptyExpression;
+			return obj is ThisReferenceExpression;
 		}
 		
 		#endregion

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Expressions/Expression.cs

@@ -16,6 +16,11 @@ namespace Debugger.Expressions
 	/// </summary>
 	public abstract partial class Expression: DebuggerObject
 	{
+		static Dictionary<Expression, Value> expressionCache;
+		static DebugeeState expressionCache_debuggerState;
+		static Thread expressionCache_thread;
+		static int expressionCache_stackDepth;
+		
 		public abstract string Code {
 			get;
 		}
@@ -31,12 +36,42 @@ namespace Debugger.Expressions
 			return this.Code;
 		}
 		
+		Value GetFromCache(StackFrame context)
+		{
+			if (expressionCache == null ||
+				expressionCache_debuggerState != context.Process.DebugeeState ||
+				expressionCache_thread != context.Thread ||
+				expressionCache_stackDepth != context.Depth)
+			{
+				expressionCache = new Dictionary<Expression, Value>();
+				expressionCache_debuggerState = context.Process.DebugeeState;
+				expressionCache_thread = context.Thread;
+				expressionCache_stackDepth = context.Depth;
+				context.Process.TraceMessage("Expression cache cleared");
+			}
+			if (expressionCache.ContainsKey(this)) {
+				Value cachedResult = expressionCache[this];
+				if (!cachedResult.HasExpired) {
+					return cachedResult;
+				}
+			}
+			return null;
+		}
+		
 		public Value Evaluate(StackFrame context)
 		{
 			if (context == null) throw new ArgumentNullException("context");
 			if (context.HasExpired) throw new DebuggerException("Context is expired StackFrame");
 			
 			Value result;
+			
+			result = GetFromCache(context);
+			if (result != null) {
+				context.Process.TraceMessage(string.Format("Cached:    {0,-12} ({1})", this.Code, this.GetType().Name));
+				return result;
+			}
+			
+			DateTime start = Debugger.Util.HighPrecisionTimer.Now;
 			try {
 				result = EvaluateInternal(context);
 			} catch (GetValueException e) {
@@ -45,8 +80,10 @@ namespace Debugger.Expressions
 				}
 				throw;
 			}
+			DateTime end = Debugger.Util.HighPrecisionTimer.Now;
+			expressionCache[this] = result;
 			
-			context.Process.TraceMessage("Evaluated " + this.GetType().Name + ": "+ this.Code);
+			context.Process.TraceMessage(string.Format("Evaluated: {0,-12} ({1}) ({2} ms)", this.Code, this.GetType().Name, (end - start).TotalMilliseconds));
 			return result;
 		}
 		

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Threads/StackFrame.cs

@@ -30,6 +30,7 @@ namespace Debugger
 		ICorDebugFunction corFunction;
 		
 		MethodInfo methodInfo;
+		int depth;
 		
 		/// <summary> The process in which this stack frame is executed </summary>
 		[Debugger.Tests.Ignore]
@@ -52,6 +53,13 @@ namespace Debugger
 			}
 		}
 		
+		/// <summary>
+		/// The depth of this frame.  First frame has depth of 0.
+		/// </summary>
+		public int Depth {
+			get { return depth; }
+		}
+		
 		/// <summary> True if the stack frame has symbols defined. 
 		/// (That is has accesss to the .pdb file) </summary>
 		public bool HasSymbols {
@@ -67,13 +75,14 @@ namespace Debugger
 			}
 		}
 		
-		internal StackFrame(Thread thread, ICorDebugILFrame corILFrame)
+		internal StackFrame(Thread thread, ICorDebugILFrame corILFrame, int depth)
 		{
 			this.process = thread.Process;
 			this.thread = thread;
 			this.corILFrame = corILFrame;
 			this.corILFramePauseSession = process.PauseSession;
 			this.corFunction = corILFrame.Function;
+			this.depth = depth;
 			
 			DebugType debugType = DebugType.Create(
 				this.Process, 

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Threads/Thread.cs

@@ -245,13 +245,15 @@ namespace Debugger
 			get {
 				process.AssertPaused();
 				
+				int depth = 0;
 				foreach(ICorDebugChain corChain in CorThread.EnumerateChains().Enumerator) {
 					if (corChain.IsManaged == 0) continue; // Only managed ones
 					foreach(ICorDebugFrame corFrame in corChain.EnumerateFrames().Enumerator) {
 						if (corFrame.Is<ICorDebugILFrame>()) {
 							StackFrame stackFrame;
 							try {
-								stackFrame = new StackFrame(this, corFrame.CastTo<ICorDebugILFrame>());
+								stackFrame = new StackFrame(this, corFrame.CastTo<ICorDebugILFrame>(), depth);
+								depth++;
 							} catch (COMException) { // TODO
 								continue;
 							};