wip: caching checkpoint

Author: NTDLS

NTDLS.ExpressionParser/ExpressionState.cs

@@ -81,20 +81,9 @@ public void StoreScanStep(ScanStepItem value)
             {
                 Array.Resize(ref _scanStep, (_scanStep.Length + 1) * 2);
             }
-            value.IsValid = true;
             _scanStep[_consumedScanStepSlots++] = value;
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void IncrementScanStep()
-        {
-            if (_consumedScanStepSlots >= _scanStep.Length) //Resize the cache if needed.
-            {
-                Array.Resize(ref _scanStep, (_scanStep.Length + 1) * 2);
-            }
-            _scanStep[_consumedScanStepSlots++] = new ScanStepItem() { IsValid = false };
-        }
-
         #endregion
 
         #region Computed Step Cache Management.

NTDLS.ExpressionParser/SubExpression.cs

@@ -283,7 +283,14 @@ private void CollapseRightAndLeft(string operation, int operationBeginIndex, out
                     var cacheKey = span.Slice(operationIndex - outParsedLength + 1, outParsedLength - 2);
                     var cachedItem = _parentExpression.State.GetPlaceholderCacheItem(cacheKey);
                     isUserVariableDerived = cachedItem.IsUserVariableDerived;
-                    _parentExpression.State.IncrementScanStep();
+
+                    _parentExpression.State.StoreScanStep(new ScanStepItem
+                    {
+                        Value = cachedItem.ComputedValue,
+                        Length = outParsedLength,
+                        IsValid = !isUserVariableDerived
+                    });
+
                     return cachedItem.ComputedValue;
                 }
                 else
@@ -311,7 +318,8 @@ private void CollapseRightAndLeft(string operation, int operationBeginIndex, out
                     _parentExpression.State.StoreScanStep(new ScanStepItem
                     {
                         Value = result,
-                        Length = outParsedLength
+                        Length = outParsedLength,
+                        IsValid = true
                     });
 
                     return result;
@@ -344,7 +352,14 @@ private void CollapseRightAndLeft(string operation, int operationBeginIndex, out
                     outParsedLength = i;
                     var cachedItem = _parentExpression.State.GetPlaceholderCacheItem(span.Slice(1, i - 2));
                     isUserVariableDerived = cachedItem.IsUserVariableDerived;
-                    _parentExpression.State.IncrementScanStep();
+
+                    _parentExpression.State.StoreScanStep(new ScanStepItem
+                    {
+                        Value = cachedItem.ComputedValue,
+                        Length = outParsedLength,
+                        IsValid = !isUserVariableDerived
+                    });
+
                     return cachedItem.ComputedValue;
                 }
                 else
@@ -365,7 +380,8 @@ private void CollapseRightAndLeft(string operation, int operationBeginIndex, out
                     _parentExpression.State.StoreScanStep(new ScanStepItem
                     {
                         Value = result,
-                        Length = outParsedLength
+                        Length = outParsedLength,
+                        IsValid = true
                     });
 
                     return result;

TestHarness/Program.cs

@@ -14,11 +14,12 @@ static void EvalPrint(string exp)
 
         static void Baseline()
         {
+            var expression = new Expression("10 * ((5 + 1000 + ( 10 )) *  60.5) * 10"); //71.8829
+
             var stopwatch = Stopwatch.StartNew();
             for (int i = 0; i < 100000; i++)
             {
-                var expression = new Expression("10 * ((5 + 1000 + ( 10 )) *  60.5) * 10"); //71.8829
-                expression.Evaluate(); //559.4445
+                expression.Evaluate(); //522.17
 
             }
             stopwatch.Stop();
@@ -29,6 +30,8 @@ static void Baseline()
 
         static void Main()
         {
+            Baseline();
+            /*
             var expression = new Expression("10 * ((5 + extra + CustomSum(11,55) + ( 10 + !0 )) * Ceil(SUM(11.6, 12.5, 14.7, 11.11)) + 60.5) * 10");
 
             expression.SetParameter("extra", 1000);
@@ -39,7 +42,7 @@ static void Main()
             });
 
             Console.WriteLine(expression.Evaluate()?.ToString() ?? "{NULL}");
-
+            */
             //var expression = new Expression("10 * ((5 + 1000 + ( 10 )) *  60.5) * 10");
             //Console.WriteLine("---FIRST---");
             //Console.WriteLine(expression.Evaluate()); //20