From 16daad2917b6ab868d75e427622dd207c5b30f3a Mon Sep 17 00:00:00 2001
From: Loretta <jozsef.b@aycode.com>
Date: Tue, 10 Mar 2026 18:35:25 +0100
Subject: [PATCH] Optimize scan codegen with compile-time property checks

Added HasScanWork and related methods to determine at compile time if a property requires scan work. EmitScanProp now skips code generation for properties proven to not need scan logic, improving efficiency and reducing unnecessary code output.
---
 .../AcBinarySourceGenerator.cs                | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/AyCode.Core.Serializers.SourceGenerator/AcBinarySourceGenerator.cs b/AyCode.Core.Serializers.SourceGenerator/AcBinarySourceGenerator.cs
index c7556c5..fc85f56 100644
--- a/AyCode.Core.Serializers.SourceGenerator/AcBinarySourceGenerator.cs
+++ b/AyCode.Core.Serializers.SourceGenerator/AcBinarySourceGenerator.cs
@@ -835,6 +835,37 @@ public class AcBinarySourceGenerator : IIncrementalGenerator
     /// Emits direct object write — bypasses GetWrapper + WriteObject entirely.
     #region Scan Pass Code Generation
 
+    /// <summary>
+    /// Compile-time check: will EmitScanProp produce any scan work for this property?
+    /// When false, the entire block (including PropertyFilter guard) is skipped.
+    /// </summary>
+    private static bool HasScanWork(PropInfo p) => p.TypeKind switch
+    {
+        PropertyTypeKind.String => p.InterningFlags != 0,
+        PropertyTypeKind.Complex when p.HasGeneratedWriter => p.ChildNeedsScan,
+        PropertyTypeKind.Complex => true,
+        PropertyTypeKind.Collection => HasCollectionScanWork(p),
+        PropertyTypeKind.Dictionary => HasDictionaryScanWork(p),
+        _ => false
+    };
+
+    private static bool HasCollectionScanWork(PropInfo p) => p.ElementKind switch
+    {
+        PropertyTypeKind.String => p.InterningFlags != 0,
+        PropertyTypeKind.Complex when p.ElementHasGeneratedWriter && p.CollectionKind != null => p.ElementNeedsScan,
+        PropertyTypeKind.Complex => true,
+        _ => false
+    };
+
+    private static bool HasDictionaryScanWork(PropInfo p)
+    {
+        if (p.DictKeyKind == PropertyTypeKind.String && p.InterningFlags != 0) return true;
+        if (p.DictValueKind == PropertyTypeKind.String && p.InterningFlags != 0) return true;
+        if (p.DictValueKind == PropertyTypeKind.Complex && p.DictValueHasGeneratedWriter) return p.DictValueNeedsScan;
+        if (p.DictValueKind == PropertyTypeKind.Complex) return true;
+        return false;
+    }
+
     /// <summary>
     /// Emits scan pass code for a single property.
     /// String: interning check + ScanInternString.
@@ -844,6 +875,9 @@ public class AcBinarySourceGenerator : IIncrementalGenerator
     /// </summary>
     private static void EmitScanProp(StringBuilder sb, PropInfo p, string i, string fullTypeName)
     {
+        // Compile-time proven: no scan work for this property — skip entirely (including PropertyFilter guard)
+        if (!HasScanWork(p)) return;
+
         var a = $"obj.{p.Name}";
 
         // PropertyFilter: must match write pass — if filter skips property, scan must skip too