Avoid reflective default key comparer creation in compiled models (NativeAOT)

src/EFCore.Design/Scaffolding/Internal/CSharpRuntimeModelCodeGenerator.cs

@@ -1254,9 +1254,10 @@ private void Create(
 
         var keyValueComparer = property.GetKeyValueComparer();
         var typeMappingKeyComparer = property.GetTypeMapping().KeyComparer;
-        if (valueComparer != keyValueComparer
-            && (!parameters.ForNativeAot || keyValueComparer != typeMappingKeyComparer)
-            && (parameters.ForNativeAot || property[CoreAnnotationNames.ValueComparer] != null))
+        if ((valueComparer != keyValueComparer
+                && (!parameters.ForNativeAot || keyValueComparer != typeMappingKeyComparer)
+                && (parameters.ForNativeAot || property[CoreAnnotationNames.ValueComparer] != null))
+            )
         {
             SetValueComparer(keyValueComparer, typeMappingKeyComparer, nameof(CoreTypeMapping.KeyComparer), propertyParameters);
         }

src/EFCore.Relational/Design/Internal/RelationalCSharpRuntimeAnnotationCodeGenerator.cs

@@ -2483,8 +2483,42 @@ public override bool Create(
             return false;
         }
 
-        var defaultInstance = (RelationalTypeMapping?)CreateDefaultTypeMapping(relationalTypeMapping, parameters);
-        if (defaultInstance == null)
+        var defaultInstance = (RelationalTypeMapping)CreateDefaultTypeMapping(relationalTypeMapping, parameters);
+        var comparer = valueComparer ?? relationalTypeMapping.Comparer;
+        var keyComparer = keyValueComparer ?? relationalTypeMapping.KeyComparer;
+        var providerComparer = providerValueComparer ?? relationalTypeMapping.ProviderValueComparer;
+        var storeTypeDifferent = relationalTypeMapping.StoreType != defaultInstance.StoreType;
+        var sizeDifferent = relationalTypeMapping.Size != null
+            && relationalTypeMapping.Size != defaultInstance.Size;
+        var precisionDifferent = relationalTypeMapping.Precision != null
+            && relationalTypeMapping.Precision != defaultInstance.Precision;
+        var scaleDifferent = relationalTypeMapping.Scale != null
+            && relationalTypeMapping.Scale != defaultInstance.Scale;
+        var dbTypeDifferent = relationalTypeMapping.DbType != null
+            && relationalTypeMapping.DbType != defaultInstance.DbType;
+        var isUnicodeDifferent = relationalTypeMapping.IsUnicode != defaultInstance.IsUnicode;
+        var isFixedLengthDifferent = relationalTypeMapping.IsFixedLength != defaultInstance.IsFixedLength;
+        var typeDifferent = relationalTypeMapping.Converter == null
+            && relationalTypeMapping.ClrType != defaultInstance.ClrType;
+        var storeTypePostfixDifferent = relationalTypeMapping.StoreTypePostfix != defaultInstance.StoreTypePostfix;
+        if (valueComparer == null
+            && keyValueComparer == null
+            && providerValueComparer == null
+            && comparer == defaultInstance.Comparer
+            && keyComparer == defaultInstance.KeyComparer
+            && providerComparer == defaultInstance.ProviderValueComparer
+            && !storeTypeDifferent
+            && !sizeDifferent
+            && !precisionDifferent
+            && !scaleDifferent
+            && !dbTypeDifferent
+            && !isUnicodeDifferent
+            && !isFixedLengthDifferent
+            && relationalTypeMapping.Converter == defaultInstance.Converter
+            && !typeDifferent
+            && !storeTypePostfixDifferent
+            && relationalTypeMapping.JsonValueReaderWriter == defaultInstance.JsonValueReaderWriter
+            && relationalTypeMapping.ElementTypeMapping == defaultInstance.ElementTypeMapping)
         {
             return true;
         }
@@ -2495,27 +2529,15 @@ public override bool Create(
 
         mainBuilder
             .Append("comparer: ");
-        Create(valueComparer ?? relationalTypeMapping.Comparer, parameters, code);
+        Create(comparer, parameters, code);
 
         mainBuilder.AppendLine(",")
             .Append("keyComparer: ");
-        Create(keyValueComparer ?? relationalTypeMapping.KeyComparer, parameters, code);
+        Create(keyComparer, parameters, code);
 
         mainBuilder.AppendLine(",")
             .Append("providerValueComparer: ");
-        Create(providerValueComparer ?? relationalTypeMapping.ProviderValueComparer, parameters, code);
-
-        var storeTypeDifferent = relationalTypeMapping.StoreType != defaultInstance.StoreType;
-        var sizeDifferent = relationalTypeMapping.Size != null
-            && relationalTypeMapping.Size != defaultInstance.Size;
-        var precisionDifferent = relationalTypeMapping.Precision != null
-            && relationalTypeMapping.Precision != defaultInstance.Precision;
-        var scaleDifferent = relationalTypeMapping.Scale != null
-            && relationalTypeMapping.Scale != defaultInstance.Scale;
-        var dbTypeDifferent = relationalTypeMapping.DbType != null
-            && relationalTypeMapping.DbType != defaultInstance.DbType;
-        var isUnicodeDifferent = relationalTypeMapping.IsUnicode != defaultInstance.IsUnicode;
-        var isFixedLengthDifferent = relationalTypeMapping.IsFixedLength != defaultInstance.IsFixedLength;
+        Create(providerComparer, parameters, code);
         if (storeTypeDifferent
             || sizeDifferent
             || precisionDifferent
@@ -2586,15 +2608,12 @@ public override bool Create(
             Create(relationalTypeMapping.Converter, parameters, code);
         }
 
-        var typeDifferent = relationalTypeMapping.Converter == null
-            && relationalTypeMapping.ClrType != defaultInstance.ClrType;
         if (typeDifferent)
         {
             mainBuilder.AppendLine(",")
                 .Append($"clrType: {code.Literal(relationalTypeMapping.ClrType)}");
         }
 
-        var storeTypePostfixDifferent = relationalTypeMapping.StoreTypePostfix != defaultInstance.StoreTypePostfix;
         if (storeTypePostfixDifferent)
         {
             mainBuilder.AppendLine(",")

src/EFCore/Design/Internal/CSharpRuntimeAnnotationCodeGenerator.cs

@@ -586,6 +586,27 @@ public static void CreateJsonValueReaderWriter(
         }
     }
 
+    /// <inheritdoc />
+    public virtual bool Create(
+        CoreTypeMapping typeMapping,
+        IProperty property,
+        CSharpRuntimeAnnotationCodeGeneratorParameters parameters)
+    {
+        var keyValueComparer = property.GetKeyValueComparer();
+        var typeMappingKeyComparer = property.GetTypeMapping().KeyComparer;
+        keyValueComparer = parameters.ForNativeAot
+            && (property.IsKey()
+                || property.IsForeignKey()
+                || property.IsUniqueIndex())
+            && keyValueComparer == typeMappingKeyComparer
+            && keyValueComparer.IsDefault()
+            && keyValueComparer.Type == property.ClrType
+                ? keyValueComparer
+                : null;
+
+        return Create(typeMapping, parameters, keyValueComparer: keyValueComparer);
+    }
+
     /// <inheritdoc />
     public virtual bool Create(
         CoreTypeMapping typeMapping,
@@ -597,7 +618,21 @@ public virtual bool Create(
         var mainBuilder = parameters.MainBuilder;
         var code = Dependencies.CSharpHelper;
         var defaultInstance = CreateDefaultTypeMapping(typeMapping, parameters);
-        if (defaultInstance == null)
+        var comparer = valueComparer ?? typeMapping.Comparer;
+        var keyComparer = keyValueComparer ?? typeMapping.KeyComparer;
+        var providerComparer = providerValueComparer ?? typeMapping.ProviderValueComparer;
+        var typeDifferent = typeMapping.Converter == null
+            && typeMapping.ClrType != defaultInstance.ClrType;
+        if (valueComparer == null
+            && keyValueComparer == null
+            && providerValueComparer == null
+            && comparer == defaultInstance.Comparer
+            && keyComparer == defaultInstance.KeyComparer
+            && providerComparer == defaultInstance.ProviderValueComparer
+            && typeMapping.Converter == defaultInstance.Converter
+            && !typeDifferent
+            && typeMapping.JsonValueReaderWriter == defaultInstance.JsonValueReaderWriter
+            && typeMapping.ElementTypeMapping == defaultInstance.ElementTypeMapping)
         {
             return true;
         }
@@ -608,15 +643,15 @@ public virtual bool Create(
 
         mainBuilder
             .Append("comparer: ");
-        Create(valueComparer ?? typeMapping.Comparer, parameters, code);
+        Create(comparer, parameters, code);
 
         mainBuilder.AppendLine(",")
             .Append("keyComparer: ");
-        Create(keyValueComparer ?? typeMapping.KeyComparer, parameters, code);
+        Create(keyComparer, parameters, code);
 
         mainBuilder.AppendLine(",")
             .Append("providerValueComparer: ");
-        Create(providerValueComparer ?? typeMapping.ProviderValueComparer, parameters, code);
+        Create(providerComparer, parameters, code);
 
         if (typeMapping.Converter != null
             && typeMapping.Converter != defaultInstance.Converter)
@@ -627,8 +662,6 @@ public virtual bool Create(
             Create(typeMapping.Converter, parameters, code);
         }
 
-        var typeDifferent = typeMapping.Converter == null
-            && typeMapping.ClrType != defaultInstance.ClrType;
         if (typeDifferent)
         {
             mainBuilder.AppendLine(",")
@@ -666,7 +699,7 @@ public virtual bool Create(
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
-    protected virtual CoreTypeMapping? CreateDefaultTypeMapping(
+    protected virtual CoreTypeMapping CreateDefaultTypeMapping(
         CoreTypeMapping typeMapping,
         CSharpRuntimeAnnotationCodeGeneratorParameters parameters)
     {
@@ -689,7 +722,6 @@ public virtual bool Create(
             .Append(code.Reference(typeMappingType))
             .Append(".Default");
 
-        var defaultInstance = (CoreTypeMapping)defaultProperty.GetValue(null)!;
-        return typeMapping == defaultInstance ? null : defaultInstance;
+        return (CoreTypeMapping)defaultProperty.GetValue(null)!;
     }
 }

test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/NativeAOT_default_key_comparer_is_emitted/DbContextAssemblyAttributes.cs

@@ -0,0 +1,9 @@
+// <auto-generated />
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using TestNamespace;
+
+#pragma warning disable 219, 612, 618
+#nullable disable
+
+[assembly: DbContextModel(typeof(DbContext), typeof(DbContextModel), ProviderName = "Microsoft.EntityFrameworkCore.InMemory")]

test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/NativeAOT_default_key_comparer_is_emitted/DbContextModel.cs

@@ -0,0 +1,47 @@
+// <auto-generated />
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+
+#pragma warning disable 219, 612, 618
+#nullable disable
+
+namespace TestNamespace;
+
+[DbContext(typeof(DbContext))]
+public partial class DbContextModel : RuntimeModel
+{
+    private static readonly bool _useOldBehavior31751 =
+        System.AppContext.TryGetSwitch("Microsoft.EntityFrameworkCore.Issue31751", out var enabled31751) && enabled31751;
+
+    static DbContextModel()
+    {
+        var model = new DbContextModel();
+
+        if (_useOldBehavior31751)
+        {
+            model.Initialize();
+        }
+        else
+        {
+            var thread = new System.Threading.Thread(RunInitialization, 10 * 1024 * 1024);
+            thread.Start();
+            thread.Join();
+
+            void RunInitialization()
+            {
+                model.Initialize();
+            }
+        }
+
+        model.Customize();
+        _instance = (DbContextModel)model.FinalizeModel();
+    }
+
+    private static DbContextModel _instance;
+    public static IModel Instance => _instance;
+
+    partial void Initialize();
+
+    partial void Customize();
+}

test/EFCore.InMemory.FunctionalTests/Scaffolding/Baselines/NativeAOT_default_key_comparer_is_emitted/DbContextModelBuilder.cs

@@ -0,0 +1,25 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+
+#pragma warning disable 219, 612, 618
+#nullable disable
+
+namespace TestNamespace;
+
+public partial class DbContextModel
+{
+    private DbContextModel()
+        : base(skipDetectChanges: false, modelId: new Guid("00000000-0000-0000-0000-000000000000"), entityTypeCount: 1)
+    {
+    }
+
+    partial void Initialize()
+    {
+        var index = IndexEntityType.Create(this);
+
+        IndexEntityType.CreateAnnotations(index);
+
+    }
+}