code reviews

lib/numerics/accel/Accel.Quantower.cs

@@ -1,4 +1,5 @@
 using System.Drawing;
+using System.Runtime.CompilerServices;
 using TradingPlatform.BusinessLayer;
 using static QuanTAlib.IndicatorExtensions;
 
@@ -19,6 +20,11 @@ public class AccelIndicator : Indicator, IWatchlistIndicator
     private Accel? _accel;
     private Func<IHistoryItem, double>? _selector;
 
+    // Cached markers to avoid per-update allocations
+    private static readonly IndicatorLineMarker GreenMarker = new(Color.Green);
+    private static readonly IndicatorLineMarker RedMarker = new(Color.Red);
+    private static readonly IndicatorLineMarker GrayMarker = new(Color.Gray);
+
     public int MinHistoryDepths => 3;
     public override string ShortName => "ACCEL";
 
@@ -47,25 +53,42 @@ public class AccelIndicator : Indicator, IWatchlistIndicator
         double value = _selector(item);
         bool isNew = args.IsNewBar();
 
-        TValue input = new(item.TimeLeft, value);
-        _accel.Update(input, isNew);
+        ProcessUpdateCore(item.TimeLeft, value, isNew);
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void ProcessUpdateCore(DateTime time, double value, bool isNew)
+    {
+        // Validate non-finite inputs - use last valid if not finite
+        if (!double.IsFinite(value))
+        {
+            value = _accel!.Last.Value;
+            if (!double.IsFinite(value))
+                value = 0.0;
+        }
+
+        TValue input = new(time, value);
+        _accel!.Update(input, isNew);
 
         bool isHot = _accel.IsHot;
+        double accelValue = _accel.Last.Value;  // Cache to avoid repeated property access
 
-        LinesSeries[0].SetValue(_accel.Last.Value, isHot, ShowColdValues);
+        LinesSeries[0].SetValue(accelValue, isHot, ShowColdValues);
         LinesSeries[1].SetValue(0);
 
         if (isHot || ShowColdValues)
         {
-            double accel = _accel.Last.Value;
-            Color color;
-            if (accel > 0)
-                color = Color.Green;
-            else if (accel < 0)
-                color = Color.Red;
-            else
-                color = Color.Gray;
-            LinesSeries[0].SetMarker(0, new IndicatorLineMarker(color));
+            // Use cached markers to avoid per-update allocations
+            IndicatorLineMarker marker = GetMarker(accelValue);
+            LinesSeries[0].SetMarker(0, marker);
         }
     }
-}
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static IndicatorLineMarker GetMarker(double value)
+    {
+        if (value > 0) return GreenMarker;
+        if (value < 0) return RedMarker;
+        return GrayMarker;
+    }
+}

lib/numerics/accel/Accel.cs

@@ -171,9 +171,14 @@ public sealed class Accel : AbstractBase
 
     public override void Prime(ReadOnlySpan<double> source, TimeSpan? step = null)
     {
-        foreach (double val in source)
+        // TValue is a readonly record struct - no heap allocation occurs
+        TimeSpan interval = step ?? TimeSpan.FromSeconds(1);
+        DateTime time = DateTime.UtcNow - (interval * source.Length);
+
+        for (int i = 0; i < source.Length; i++)
         {
-            Update(new TValue(DateTime.MinValue, val));
+            Update(new TValue(time, source[i]), true);
+            time += interval;
         }
     }
 
@@ -300,4 +305,4 @@ public sealed class Accel : AbstractBase
         if (double.IsFinite(c)) return c;
         return 0.0;
     }
-}
+}