Query: Make CreateReadValueExpression an extension method

This method is to read a particular index from valueBuffer for a property.
It was in EntityMaterializerSource as an instance method in order for provider to influence how values are read from valueBuffer.
In new query pipeline, providers are supposed to convert valueBuffer read to their database object read. Further, even if they want to create a ValueBuffer for read, the valueBuffer should have values after all custom processing.
Hence there is no particular need to make this overridable behavior. Making it extension method simplify quite a lot of things.

(note: functionality to use this was available anyway since the method it invoke was also publicly exposed as static.

src/EFCore.Cosmos/Query/Internal/CosmosShapedQueryCompilingExpressionVisitor.CosmosProjectionBindingRemovingExpressionVisitor.cs

@@ -187,7 +187,7 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
 
                 var method = methodCallExpression.Method;
                 var genericMethod = method.IsGenericMethod ? method.GetGenericMethodDefinition() : null;
-                if (genericMethod == EntityMaterializerSource.TryReadValueMethod)
+                if (genericMethod == EntityFrameworkCore.Infrastructure.ExpressionExtensions.ValueBufferTryReadValueMethod)
                 {
                     var property = (IProperty)((ConstantExpression)methodCallExpression.Arguments[2]).Value;
                     Expression innerExpression;

src/EFCore.InMemory/Query/Internal/InMemoryExpressionTranslatingExpressionVisitor.cs

@@ -17,6 +17,7 @@
 using Microsoft.EntityFrameworkCore.Query;
 using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Utilities;
+using ExpressionExtensions = Microsoft.EntityFrameworkCore.Infrastructure.ExpressionExtensions;
 
 namespace Microsoft.EntityFrameworkCore.InMemory.Query.Internal
 {
@@ -399,7 +400,7 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
             Check.NotNull(methodCallExpression, nameof(methodCallExpression));
 
             if (methodCallExpression.Method.IsGenericMethod
-                && methodCallExpression.Method.GetGenericMethodDefinition() == EntityMaterializerSource.TryReadValueMethod)
+                && methodCallExpression.Method.GetGenericMethodDefinition() == ExpressionExtensions.ValueBufferTryReadValueMethod)
             {
                 return methodCallExpression;
             }

src/EFCore.InMemory/Query/Internal/InMemoryQueryExpression.cs

@@ -8,12 +8,14 @@
 using System.Reflection;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Diagnostics;
+using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.InMemory.Internal;
 using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Metadata.Internal;
 using Microsoft.EntityFrameworkCore.Query;
 using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Utilities;
+using ExpressionExtensions = Microsoft.EntityFrameworkCore.Infrastructure.ExpressionExtensions;
 
 namespace Microsoft.EntityFrameworkCore.InMemory.Query.Internal
 {
@@ -324,7 +326,7 @@ public virtual void ApplyDefaultIfEmpty()
         private static IPropertyBase InferPropertyFromInner(Expression expression)
             => expression is MethodCallExpression methodCallExpression
                 && methodCallExpression.Method.IsGenericMethod
-                && methodCallExpression.Method.GetGenericMethodDefinition() == EntityMaterializerSource.TryReadValueMethod
+                && methodCallExpression.Method.GetGenericMethodDefinition() == ExpressionExtensions.ValueBufferTryReadValueMethod
                 ? (IPropertyBase)((ConstantExpression)methodCallExpression.Arguments[2]).Value
                 : null;
 
@@ -440,24 +442,15 @@ private Expression GetGroupingKey(Expression key, List<Expression> groupingExpre
                 default:
                     var index = groupingExpressions.Count;
                     groupingExpressions.Add(key);
-                    return CreateReadValueExpression(
-                        groupingKeyAccessExpression,
+                    return groupingKeyAccessExpression.CreateValueBufferReadValueExpression(
                         key.Type,
                         index,
                         InferPropertyFromInner(key));
             }
         }
 
-        private static Expression CreateReadValueExpression(
-            Expression valueBufferParameter, Type type, int index, IPropertyBase property)
-            => Call(
-                EntityMaterializerSource.TryReadValueMethod.MakeGenericMethod(type),
-                valueBufferParameter,
-                Constant(index),
-                Constant(property, typeof(IPropertyBase)));
-
         private Expression CreateReadValueExpression(Type type, int index, IPropertyBase property)
-            => CreateReadValueExpression(_valueBufferParameter, type, index, property);
+            => _valueBufferParameter.CreateValueBufferReadValueExpression(type, index, property);
 
         public virtual void AddInnerJoin(
             [NotNull] InMemoryQueryExpression innerQueryExpression,
@@ -943,11 +936,11 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                 Check.NotNull(methodCallExpression, nameof(methodCallExpression));
 
                 if (methodCallExpression.Method.IsGenericMethod
-                    && methodCallExpression.Method.GetGenericMethodDefinition() == EntityMaterializerSource.TryReadValueMethod
+                    && methodCallExpression.Method.GetGenericMethodDefinition() == ExpressionExtensions.ValueBufferTryReadValueMethod
                     && !methodCallExpression.Type.IsNullableType())
                 {
                     return Call(
-                        EntityMaterializerSource.TryReadValueMethod.MakeGenericMethod(methodCallExpression.Type.MakeNullable()),
+                        ExpressionExtensions.ValueBufferTryReadValueMethod.MakeGenericMethod(methodCallExpression.Type.MakeNullable()),
                         methodCallExpression.Arguments);
                 }
 

src/EFCore.InMemory/Query/Internal/InMemoryShapedQueryCompilingExpressionVisitor.InMemoryProjectionBindingRemovingExpressionVisitor.cs

@@ -9,6 +9,7 @@
 using Microsoft.EntityFrameworkCore.Query;
 using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Utilities;
+using ExpressionExtensions = Microsoft.EntityFrameworkCore.Infrastructure.ExpressionExtensions;
 
 namespace Microsoft.EntityFrameworkCore.InMemory.Query.Internal
 {
@@ -61,7 +62,7 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                 Check.NotNull(methodCallExpression, nameof(methodCallExpression));
 
                 if (methodCallExpression.Method.IsGenericMethod
-                    && methodCallExpression.Method.GetGenericMethodDefinition() == EntityMaterializerSource.TryReadValueMethod)
+                    && methodCallExpression.Method.GetGenericMethodDefinition() == ExpressionExtensions.ValueBufferTryReadValueMethod)
                 {
                     var property = (IProperty)((ConstantExpression)methodCallExpression.Arguments[2]).Value;
                     var (indexMap, valueBuffer) =
@@ -88,11 +89,10 @@ protected override Expression VisitExtension(Expression extensionExpression)
                     var projectionIndex = (int)GetProjectionIndex(queryExpression, projectionBindingExpression);
                     var valueBuffer = queryExpression.CurrentParameter;
 
-                    return Expression.Call(
-                        EntityMaterializerSource.TryReadValueMethod.MakeGenericMethod(projectionBindingExpression.Type),
-                        valueBuffer,
-                        Expression.Constant(projectionIndex),
-                        Expression.Constant(InferPropertyFromInner(queryExpression.Projection[projectionIndex]), typeof(IPropertyBase)));
+                    return valueBuffer.CreateValueBufferReadValueExpression(
+                        projectionBindingExpression.Type,
+                        projectionIndex,
+                        InferPropertyFromInner(queryExpression.Projection[projectionIndex]));
                 }
 
                 return base.VisitExtension(extensionExpression);
@@ -102,7 +102,7 @@ private IPropertyBase InferPropertyFromInner(Expression expression)
             {
                 if (expression is MethodCallExpression methodCallExpression
                     && methodCallExpression.Method.IsGenericMethod
-                    && methodCallExpression.Method.GetGenericMethodDefinition() == EntityMaterializerSource.TryReadValueMethod)
+                    && methodCallExpression.Method.GetGenericMethodDefinition() == ExpressionExtensions.ValueBufferTryReadValueMethod)
                 {
                     return (IPropertyBase)((ConstantExpression)methodCallExpression.Arguments[2]).Value;
                 }

src/EFCore.Relational/Query/RelationalShapedQueryCompilingExpressionVisitor.RelationalProjectionBindingRemovingExpressionVisitor.cs

@@ -92,7 +92,7 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                 Check.NotNull(methodCallExpression, nameof(methodCallExpression));
 
                 if (methodCallExpression.Method.IsGenericMethod
-                    && methodCallExpression.Method.GetGenericMethodDefinition() == EntityMaterializerSource.TryReadValueMethod)
+                    && methodCallExpression.Method.GetGenericMethodDefinition() == Infrastructure.ExpressionExtensions.ValueBufferTryReadValueMethod)
                 {
                     var property = (IProperty)((ConstantExpression)methodCallExpression.Arguments[2]).Value;
                     var propertyProjectionMap = methodCallExpression.Arguments[0] is ProjectionBindingExpression projectionBindingExpression

src/EFCore/Infrastructure/ExpressionExtensions.cs

@@ -6,11 +6,13 @@
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Diagnostics;
 using Microsoft.EntityFrameworkCore.Internal;
 using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Query;
+using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Utilities;
 
 namespace Microsoft.EntityFrameworkCore.Infrastructure
@@ -225,5 +227,48 @@ var propertyPaths
 
             return propertyPaths;
         }
+
+        /// <summary>
+        ///     <para>
+        ///         Creates an <see cref="Expression" /> tree representing reading a value from a <see cref="ValueBuffer" />
+        ///     </para>
+        ///     <para>
+        ///         This method is typically used by database providers (and other extensions). It is generally
+        ///         not used in application code.
+        ///     </para>
+        /// </summary>
+        /// <param name="valueBuffer"> The expression that exposes the <see cref="ValueBuffer" />. </param>
+        /// <param name="type"> The type to read. </param>
+        /// <param name="index"> The index in the buffer to read from. </param>
+        /// <param name="property"> The IPropertyBase being read if any. </param>
+        /// <returns> An expression to read the value. </returns>
+        public static Expression CreateValueBufferReadValueExpression(
+            [NotNull] this Expression valueBuffer,
+            [NotNull] Type type,
+            int index,
+            [CanBeNull] IPropertyBase property)
+            => Expression.Call(
+                ValueBufferTryReadValueMethod.MakeGenericMethod(type),
+                valueBuffer,
+                Expression.Constant(index),
+                Expression.Constant(property, typeof(IPropertyBase)));
+
+        /// <summary>
+        ///     <para>
+        ///         MethodInfo which is used to generate an <see cref="Expression" /> tree representing reading a value from a <see cref="ValueBuffer" />
+        ///     </para>
+        ///     <para>
+        ///         This method is typically used by database providers (and other extensions). It is generally
+        ///         not used in application code.
+        ///     </para>
+        /// </summary>
+        public static readonly MethodInfo ValueBufferTryReadValueMethod
+            = typeof(ExpressionExtensions).GetTypeInfo()
+                .GetDeclaredMethod(nameof(ValueBufferTryReadValue));
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static TValue ValueBufferTryReadValue<TValue>(
+            in ValueBuffer valueBuffer, int index, IPropertyBase property)
+            => valueBuffer[index] is TValue value ? value : default;
     }
 }

src/EFCore/Metadata/PropertyParameterBinding.cs

@@ -3,6 +3,7 @@
 
 using System.Linq.Expressions;
 using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Query;
 using Microsoft.EntityFrameworkCore.Storage;
 
@@ -33,11 +34,8 @@ public override Expression BindToParameter(ParameterBindingInfo bindingInfo)
         {
             var property = ConsumedProperties[0];
 
-            return Expression.Call(
-                EntityMaterializerSource.TryReadValueMethod.MakeGenericMethod(property.ClrType),
-                Expression.Call(bindingInfo.MaterializationContextExpression, MaterializationContext.GetValueBufferMethod),
-                Expression.Constant(bindingInfo.GetValueBufferIndex(property)),
-                Expression.Constant(property, typeof(IPropertyBase)));
+            return Expression.Call(bindingInfo.MaterializationContextExpression, MaterializationContext.GetValueBufferMethod)
+                   .CreateValueBufferReadValueExpression(property.ClrType, bindingInfo.GetValueBufferIndex(property), property);
         }
     }
 }

src/EFCore/Query/EntityMaterializerSource.cs

@@ -34,26 +34,6 @@ public EntityMaterializerSource([NotNull] EntityMaterializerSourceDependencies d
         {
         }
 
-        public virtual Expression CreateReadValueExpression(
-            Expression valueBufferExpression,
-            Type type,
-            int index,
-            IPropertyBase property)
-            => Expression.Call(
-                TryReadValueMethod.MakeGenericMethod(type),
-                valueBufferExpression,
-                Expression.Constant(index),
-                Expression.Constant(property, typeof(IPropertyBase)));
-
-        public static readonly MethodInfo TryReadValueMethod
-            = typeof(EntityMaterializerSource).GetTypeInfo()
-                .GetDeclaredMethod(nameof(TryReadValue));
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static TValue TryReadValue<TValue>(
-            in ValueBuffer valueBuffer, int index, IPropertyBase property)
-            => valueBuffer[index] is TValue value ? value : default;
-
         public virtual Expression CreateMaterializeExpression(
             IEntityType entityType,
             string entityInstanceName,
@@ -127,8 +107,7 @@ var blockExpressions
                 var readValueExpression
                     = property is IServiceProperty serviceProperty
                         ? serviceProperty.GetParameterBinding().BindToParameter(bindingInfo)
-                        : CreateReadValueExpression(
-                            valueBufferExpression,
+                        : valueBufferExpression.CreateValueBufferReadValueExpression(
                             memberInfo.GetMemberType(),
                             property.GetIndex(),
                             property);

src/EFCore/Query/IEntityMaterializerSource.cs

@@ -27,26 +27,6 @@ namespace Microsoft.EntityFrameworkCore.Query
     /// </summary>
     public interface IEntityMaterializerSource
     {
-        /// <summary>
-        ///     <para>
-        ///         Creates an <see cref="Expression" /> tree representing reading a value from a <see cref="ValueBuffer" />
-        ///     </para>
-        ///     <para>
-        ///         This method is typically used by database providers (and other extensions). It is generally
-        ///         not used in application code.
-        ///     </para>
-        /// </summary>
-        /// <param name="valueBuffer"> The expression that exposes the <see cref="ValueBuffer" />. </param>
-        /// <param name="type"> The type to read. </param>
-        /// <param name="index"> The index in the buffer to read from. </param>
-        /// <param name="property"> The IPropertyBase being read if any. </param>
-        /// <returns> An expression to read the value. </returns>
-        Expression CreateReadValueExpression(
-            [NotNull] Expression valueBuffer,
-            [NotNull] Type type,
-            int index,
-            [CanBeNull] IPropertyBase property);
-
         /// <summary>
         ///     <para>
         ///         Creates an <see cref="Expression" /> tree representing creating an entity instance.

src/EFCore/Query/ShapedQueryCompilingExpressionVisitor.cs

@@ -11,6 +11,7 @@
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.ChangeTracking.Internal;
 using Microsoft.EntityFrameworkCore.Diagnostics;
+using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Internal;
 using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Metadata.Internal;
@@ -372,8 +373,7 @@ private Expression ProcessEntityShaper(EntityShaperExpression entityShaperExpres
                                     typeof(object),
                                     primaryKey.Properties
                                         .Select(
-                                            p => _entityMaterializerSource.CreateReadValueExpression(
-                                                valueBufferExpression,
+                                            p => valueBufferExpression.CreateValueBufferReadValueExpression(
                                                 typeof(object),
                                                 p.GetIndex(),
                                                 p))),
@@ -407,8 +407,7 @@ private Expression ProcessEntityShaper(EntityShaperExpression entityShaperExpres
                         expressions.Add(Expression.IfThen(
                             primaryKey.Properties.Select(
                                 p => Expression.NotEqual(
-                                        _entityMaterializerSource.CreateReadValueExpression(
-                                            valueBufferExpression, typeof(object), p.GetIndex(), p),
+                                        valueBufferExpression.CreateValueBufferReadValueExpression(typeof(object), p.GetIndex(), p),
                                         Expression.Constant(null)))
                                 .Aggregate((a, b) => Expression.AndAlso(a, b)),
                             MaterializeEntity(
@@ -424,8 +423,7 @@ private Expression ProcessEntityShaper(EntityShaperExpression entityShaperExpres
                                         .Select(
                                             p =>
                                                 Expression.NotEqual(
-                                                    _entityMaterializerSource.CreateReadValueExpression(
-                                                        valueBufferExpression,
+                                                    valueBufferExpression.CreateValueBufferReadValueExpression(
                                                         typeof(object),
                                                         p.GetIndex(),
                                                         p),
@@ -486,8 +484,7 @@ private Expression MaterializeEntity(
                     expressions.Add(
                         Expression.Assign(
                             discriminatorValueVariable,
-                            _entityMaterializerSource.CreateReadValueExpression(
-                                valueBufferExpression,
+                            valueBufferExpression.CreateValueBufferReadValueExpression(
                                 discriminatorProperty.ClrType,
                                 discriminatorProperty.GetIndex(),
                                 discriminatorProperty)));
@@ -578,11 +575,7 @@ private BlockExpression CreateFullMaterializeExpression(
                                 Expression.NewArrayInit(
                                     typeof(object),
                                     shadowProperties.Select(
-                                        p => _entityMaterializerSource.CreateReadValueExpression(
-                                            valueBufferExpression,
-                                            typeof(object),
-                                            p.GetIndex(),
-                                            p))))));
+                                        p => valueBufferExpression.CreateValueBufferReadValueExpression(typeof(object), p.GetIndex(), p))))));
                 }
 
                 materializer = materializer.Type == returnType