Introduce liftable constants to shaper to prepare for precompilation

Part of dotnet#25009

EFCore.sln.DotSettings

@@ -301,6 +301,7 @@ The .NET Foundation licenses this file to you under the MIT license.
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Includable/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=initializers/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=keyless/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=liftable/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Lite_0027s/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=materializer/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=materializers/@EntryIndexedValue">True</s:Boolean>

src/EFCore.Relational/Infrastructure/EntityFrameworkRelationalServicesBuilder.cs

@@ -62,6 +62,7 @@ public static readonly IDictionary<Type, ServiceCharacteristics> RelationalServi
             { typeof(IRawSqlCommandBuilder), new ServiceCharacteristics(ServiceLifetime.Singleton) },
             { typeof(IQuerySqlGeneratorFactory), new ServiceCharacteristics(ServiceLifetime.Singleton) },
             { typeof(IModificationCommandFactory), new ServiceCharacteristics(ServiceLifetime.Singleton) },
+            { typeof(IRelationalLiftableConstantFactory), new ServiceCharacteristics(ServiceLifetime.Singleton) },
             { typeof(ICommandBatchPreparer), new ServiceCharacteristics(ServiceLifetime.Scoped) },
             { typeof(IModificationCommandBatchFactory), new ServiceCharacteristics(ServiceLifetime.Scoped) },
             { typeof(IRelationalSqlTranslatingExpressionVisitorFactory), new ServiceCharacteristics(ServiceLifetime.Scoped) },
@@ -185,6 +186,9 @@ public override EntityFrameworkServicesBuilder TryAddCoreServices()
         TryAdd<IRelationalParameterBasedSqlProcessorFactory, RelationalParameterBasedSqlProcessorFactory>();
         TryAdd<IRelationalQueryStringFactory, RelationalQueryStringFactory>();
         TryAdd<IQueryCompilationContextFactory, RelationalQueryCompilationContextFactory>();
+        TryAdd<ILiftableConstantFactory>(p => p.GetRequiredService<IRelationalLiftableConstantFactory>());
+        TryAdd<IRelationalLiftableConstantFactory, RelationalLiftableConstantFactory>();
+        TryAdd<ILiftableConstantProcessor, RelationalLiftableConstantProcessor>();
 
         ServiceCollectionMap.GetInfrastructure()
             .AddDependencySingleton<RelationalSqlGenerationHelperDependencies>()

src/EFCore.Relational/Query/IRelationalLiftableConstantFactory.cs

@@ -0,0 +1,12 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+public interface IRelationalLiftableConstantFactory : ILiftableConstantFactory
+{
+    LiftableConstantExpression CreateLiftableConstant(
+        Expression<Func<RelationalMaterializerLiftableConstantContext, object>> resolverExpression,
+        string variableName,
+        Type type);
+}

src/EFCore.Relational/Query/Internal/RelationalProjectionBindingExpressionVisitor.cs

@@ -653,7 +653,8 @@ private ProjectionBindingExpression AddClientProjection(Expression expression, T
         return new ProjectionBindingExpression(_selectExpression, existingIndex, type);
     }
 
-    private static T GetParameterValue<T>(QueryContext queryContext, string parameterName)
+    // Public because can get referenced by precompiled shaper code
+    public static T GetParameterValue<T>(QueryContext queryContext, string parameterName)
 #pragma warning restore IDE0052 // Remove unread private members
         => (T)queryContext.ParameterValues[parameterName]!;
 

src/EFCore.Relational/Query/Internal/SingleQueryingEnumerable.cs

@@ -6,6 +6,28 @@
 
 namespace Microsoft.EntityFrameworkCore.Query.Internal;
 
+public static class SingleQueryingEnumerable
+{
+    public static SingleQueryingEnumerable<T> Create<T>(
+        RelationalQueryContext relationalQueryContext,
+        RelationalCommandCache relationalCommandCache,
+        IReadOnlyList<ReaderColumn?>? readerColumns,
+        Func<QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator, T> shaper,
+        Type contextType,
+        bool standAloneStateManager,
+        bool detailedErrorsEnabled,
+        bool threadSafetyChecksEnabled)
+        => new(
+            relationalQueryContext,
+            relationalCommandCache,
+            readerColumns,
+            shaper,
+            contextType,
+            standAloneStateManager,
+            detailedErrorsEnabled,
+            threadSafetyChecksEnabled);
+}
+
 /// <summary>
 ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
 ///     the same compatibility standards as public APIs. It may be changed or removed without notice in

src/EFCore.Relational/Query/RelationalLiftableConstantFactory.cs

@@ -0,0 +1,13 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+public class RelationalLiftableConstantFactory : LiftableConstantFactory, IRelationalLiftableConstantFactory
+{
+    public virtual LiftableConstantExpression CreateLiftableConstant(
+        Expression<Func<RelationalMaterializerLiftableConstantContext, object>> resolverExpression,
+        string variableName,
+        Type type)
+        => new(resolverExpression, variableName, type);
+}

src/EFCore.Relational/Query/RelationalLiftableConstantProcessor.cs

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.EntityFrameworkCore.Query.Internal;
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+#pragma warning disable EF1001 // LiftableConstantProcessor is internal
+
+public class RelationalLiftableConstantProcessor : LiftableConstantProcessor
+{
+    private RelationalMaterializerLiftableConstantContext _relationalMaterializerLiftableConstantContext;
+
+    public RelationalLiftableConstantProcessor(
+        ShapedQueryCompilingExpressionVisitorDependencies dependencies,
+        RelationalShapedQueryCompilingExpressionVisitorDependencies relationalDependencies)
+        : base(dependencies)
+        => _relationalMaterializerLiftableConstantContext = new(dependencies, relationalDependencies);
+
+    protected override ConstantExpression InlineConstant(LiftableConstantExpression liftableConstant)
+    {
+        if (liftableConstant.ResolverExpression is Expression<Func<RelationalMaterializerLiftableConstantContext, object>>
+            resolverExpression)
+        {
+            var resolver = resolverExpression.Compile(preferInterpretation: true);
+            var value = resolver(_relationalMaterializerLiftableConstantContext);
+            return Expression.Constant(value, liftableConstant.Type);
+        }
+
+        return base.InlineConstant(liftableConstant);
+    }
+}

src/EFCore.Relational/Query/RelationalMaterializerLiftableConstantContext.cs

@@ -0,0 +1,9 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+public record RelationalMaterializerLiftableConstantContext(
+        ShapedQueryCompilingExpressionVisitorDependencies Dependencies,
+        RelationalShapedQueryCompilingExpressionVisitorDependencies RelationalDependencies)
+    : MaterializerLiftableConstantContext(Dependencies);

src/EFCore.Relational/Query/RelationalShapedQueryCompilingExpressionVisitor.ShaperProcessingExpressionVisitor.ClientMethods.cs

@@ -11,7 +11,14 @@ namespace Microsoft.EntityFrameworkCore.Query;
 
 public partial class RelationalShapedQueryCompilingExpressionVisitor
 {
-    private sealed partial class ShaperProcessingExpressionVisitor : ExpressionVisitor
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     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>
+    [EntityFrameworkInternal]
+    public sealed partial class ShaperProcessingExpressionVisitor : ExpressionVisitor
     {
         private static readonly MethodInfo ThrowReadValueExceptionMethod =
             typeof(ShaperProcessingExpressionVisitor).GetTypeInfo().GetDeclaredMethod(nameof(ThrowReadValueException))!;
@@ -160,7 +167,14 @@ private static void IncludeReference<TEntity, TIncludingEntity, TIncludedEntity>
             }
         }
 
-        private static void InitializeIncludeCollection<TParent, TNavigationEntity>(
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     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>
+        [EntityFrameworkInternal]
+        public static void InitializeIncludeCollection<TParent, TNavigationEntity>(
             int collectionId,
             QueryContext queryContext,
             DbDataReader dbDataReader,
@@ -201,17 +215,27 @@ private static void InitializeIncludeCollection<TParent, TNavigationEntity>(
             resultCoordinator.SetSingleQueryCollectionContext(collectionId, collectionMaterializationContext);
         }
 
-        private static void PopulateIncludeCollection<TIncludingEntity, TIncludedEntity>(
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     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>
+        [EntityFrameworkInternal]
+        public static void PopulateIncludeCollection<TIncludingEntity, TIncludedEntity>(
             int collectionId,
             QueryContext queryContext,
             DbDataReader dbDataReader,
             SingleQueryResultCoordinator resultCoordinator,
             Func<QueryContext, DbDataReader, object[]> parentIdentifier,
             Func<QueryContext, DbDataReader, object[]> outerIdentifier,
             Func<QueryContext, DbDataReader, object[]> selfIdentifier,
-            IReadOnlyList<ValueComparer> parentIdentifierValueComparers,
-            IReadOnlyList<ValueComparer> outerIdentifierValueComparers,
-            IReadOnlyList<ValueComparer> selfIdentifierValueComparers,
+            IReadOnlyList<Func<object, object, bool>> parentIdentifierValueComparers,
+            IReadOnlyList<Func<object, object, bool>> outerIdentifierValueComparers,
+            IReadOnlyList<Func<object, object, bool>> selfIdentifierValueComparers,
+            // IReadOnlyList<ValueComparer> parentIdentifierValueComparers,
+            // IReadOnlyList<ValueComparer> outerIdentifierValueComparers,
+            // IReadOnlyList<ValueComparer> selfIdentifierValueComparers,
             Func<QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator, TIncludedEntity> innerShaper,
             INavigationBase? inverseNavigation,
             Action<TIncludingEntity, TIncludedEntity> fixup,
@@ -229,14 +253,14 @@ private static void PopulateIncludeCollection<TIncludingEntity, TIncludedEntity>
                     return;
                 }
 
-                if (!CompareIdentifiers(
+                if (!CompareIdentifiers2(
                         outerIdentifierValueComparers,
                         outerIdentifier(queryContext, dbDataReader), collectionMaterializationContext.OuterIdentifier))
                 {
                     // Outer changed so collection has ended. Materialize last element.
                     GenerateCurrentElementIfPending();
                     // If parent also changed then this row is now pointing to element of next collection
-                    if (!CompareIdentifiers(
+                    if (!CompareIdentifiers2(
                             parentIdentifierValueComparers,
                             parentIdentifier(queryContext, dbDataReader), collectionMaterializationContext.ParentIdentifier))
                     {
@@ -255,7 +279,7 @@ private static void PopulateIncludeCollection<TIncludingEntity, TIncludedEntity>
 
                 if (collectionMaterializationContext.SelfIdentifier != null)
                 {
-                    if (CompareIdentifiers(selfIdentifierValueComparers, innerKey, collectionMaterializationContext.SelfIdentifier))
+                    if (CompareIdentifiers2(selfIdentifierValueComparers, innerKey, collectionMaterializationContext.SelfIdentifier))
                     {
                         // repeated row for current element
                         // If it is pending materialization then it may have nested elements
@@ -319,7 +343,14 @@ void GenerateCurrentElementIfPending()
             }
         }
 
-        private static void InitializeSplitIncludeCollection<TParent, TNavigationEntity>(
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     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>
+        [EntityFrameworkInternal]
+        public static void InitializeSplitIncludeCollection<TParent, TNavigationEntity>(
             int collectionId,
             QueryContext queryContext,
             DbDataReader parentDataReader,
@@ -358,7 +389,14 @@ private static void InitializeSplitIncludeCollection<TParent, TNavigationEntity>
             resultCoordinator.SetSplitQueryCollectionContext(collectionId, splitQueryCollectionContext);
         }
 
-        private static void PopulateSplitIncludeCollection<TIncludingEntity, TIncludedEntity>(
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     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>
+        [EntityFrameworkInternal]
+        public static void PopulateSplitIncludeCollection<TIncludingEntity, TIncludedEntity>(
             int collectionId,
             RelationalQueryContext queryContext,
             IExecutionStrategy executionStrategy,
@@ -367,7 +405,8 @@ private static void PopulateSplitIncludeCollection<TIncludingEntity, TIncludedEn
             bool detailedErrorsEnabled,
             SplitQueryResultCoordinator resultCoordinator,
             Func<QueryContext, DbDataReader, object[]> childIdentifier,
-            IReadOnlyList<ValueComparer> identifierValueComparers,
+            IReadOnlyList<Func<object, object, bool>> identifierValueComparers,
+            // IReadOnlyList<ValueComparer> identifierValueComparers,
             Func<QueryContext, DbDataReader, ResultContext, SplitQueryResultCoordinator, TIncludedEntity> innerShaper,
             Action<QueryContext, IExecutionStrategy, SplitQueryResultCoordinator>? relatedDataLoaders,
             INavigationBase? inverseNavigation,
@@ -414,7 +453,7 @@ static RelationalDataReader InitializeReader(
             {
                 while (dataReaderContext.HasNext ?? dbDataReader.Read())
                 {
-                    if (!CompareIdentifiers(
+                    if (!CompareIdentifiers2(
                             identifierValueComparers,
                             splitQueryCollectionContext.ParentIdentifier, childIdentifier(queryContext, dbDataReader)))
                     {
@@ -451,7 +490,8 @@ private static async Task PopulateSplitIncludeCollectionAsync<TIncludingEntity,
             bool detailedErrorsEnabled,
             SplitQueryResultCoordinator resultCoordinator,
             Func<QueryContext, DbDataReader, object[]> childIdentifier,
-            IReadOnlyList<ValueComparer> identifierValueComparers,
+            IReadOnlyList<Func<object, object, bool>> identifierValueComparers,
+            // IReadOnlyList<ValueComparer> identifierValueComparers,
             Func<QueryContext, DbDataReader, ResultContext, SplitQueryResultCoordinator, TIncludedEntity> innerShaper,
             Func<QueryContext, IExecutionStrategy, SplitQueryResultCoordinator, Task>? relatedDataLoaders,
             INavigationBase? inverseNavigation,
@@ -506,7 +546,7 @@ static async Task<RelationalDataReader> InitializeReaderAsync(
             {
                 while (dataReaderContext.HasNext ?? await dbDataReader.ReadAsync(queryContext.CancellationToken).ConfigureAwait(false))
                 {
-                    if (!CompareIdentifiers(
+                    if (!CompareIdentifiers2(
                             identifierValueComparers,
                             splitQueryCollectionContext.ParentIdentifier, childIdentifier(queryContext, dbDataReader)))
                     {
@@ -538,7 +578,8 @@ static async Task<RelationalDataReader> InitializeReaderAsync(
             }
         }
 
-        private static TCollection InitializeCollection<TElement, TCollection>(
+        [EntityFrameworkInternal]
+        public static TCollection InitializeCollection<TElement, TCollection>(
             int collectionId,
             QueryContext queryContext,
             DbDataReader dbDataReader,
@@ -560,7 +601,8 @@ private static TCollection InitializeCollection<TElement, TCollection>(
             return (TCollection)collection;
         }
 
-        private static void PopulateCollection<TCollection, TElement, TRelatedEntity>(
+        [EntityFrameworkInternal]
+        public static void PopulateCollection<TCollection, TElement, TRelatedEntity>(
             int collectionId,
             QueryContext queryContext,
             DbDataReader dbDataReader,
@@ -1066,6 +1108,20 @@ private static async Task TaskAwaiter(Func<Task>[] taskFactories)
             }
         }
 
+        private static bool CompareIdentifiers2(IReadOnlyList<Func<object, object, bool>> valueComparers, object[] left, object[] right)
+        {
+            // Ignoring size check on all for perf as they should be same unless bug in code.
+            for (var i = 0; i < left.Length; i++)
+            {
+                if (!valueComparers[i](left[i], right[i]))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
         private static bool CompareIdentifiers(IReadOnlyList<ValueComparer> valueComparers, object[] left, object[] right)
         {
             // Ignoring size check on all for perf as they should be same unless bug in code.