Getting getter method of indexer property improved

+ small QueryHelper improvements

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Linq/Materialization/ExpressionMaterializer.cs

@@ -483,9 +483,7 @@ private Expression MaterializeThroughOwner(Expression target, Expression tuple,
         var materializedOwner = MaterializeThroughOwner((Expression) owner, tuple, defaultIfEmpty);
         Expression fieldExpression;
         if (field.Field.IsDynamicallyDefined) {
-          var attributes = materializedOwner.Type.GetCustomAttributes(WellKnownTypes.DefaultMemberAttribute, true);
-          var indexerPropertyName = ((DefaultMemberAttribute) attributes.Single()).MemberName;
-          var methodInfo = materializedOwner.Type.GetProperty(indexerPropertyName).GetGetMethod();
+          var methodInfo = materializedOwner.Type.GetProperty(Reflection.WellKnown.IndexerPropertyName).GetGetMethod();
           fieldExpression = Expression.Convert(Expression.Call(materializedOwner, methodInfo, Expression.Constant(field.Field.Name)), field.Field.ValueType);
         }
         else

Orm/Xtensive.Orm/Orm/Linq/QueryHelper.cs

@@ -25,6 +25,8 @@ internal static class QueryHelper
   {
     private sealed class OwnerWrapper<TOwner>
     {
+      public static readonly Type GenericDef = typeof(OwnerWrapper<>);
+
       public TOwner Owner { get; set; }
 
       public OwnerWrapper(TOwner owner)
@@ -76,22 +78,29 @@ public static bool IsDirectEntitySetQuery(Expression entitySet)
         return false;
       var wrapper = ((MemberExpression) owner).Expression;
       return wrapper.NodeType==ExpressionType.Constant
-        && wrapper.Type.IsGenericType
-        && wrapper.Type.GetGenericTypeDefinition()==typeof (OwnerWrapper<>);
+        && wrapper.Type.IsOwnerWrapper();
     }
 
     public static Expression CreateDirectEntitySetQuery(EntitySetBase entitySet)
     {
       // A hack making expression to look like regular parameter 
       // (ParameterExtractor.IsParameter => true)
       var owner = entitySet.Owner;
+      var ownerType = owner.TypeInfo.UnderlyingType;
       var wrapper = Activator.CreateInstance(
-        typeof (OwnerWrapper<>).MakeGenericType(owner.GetType()), owner);
-      var wrappedOwner = Expression.Property(Expression.Constant(wrapper), "Owner");
+        OwnerWrapper<int>.GenericDef.MakeGenericType(ownerType), owner);
+      var wrappedOwner = Expression.Property(Expression.Constant(wrapper), nameof(OwnerWrapper<int>.Owner));
       if (!entitySet.Field.IsDynamicallyDefined) {
         return Expression.Property(wrappedOwner, entitySet.Field.UnderlyingProperty);
       }
-      var indexers = owner.GetType().GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
+      //fast way to get indexer getter method
+      var indexerGetter = ownerType.GetMethod(Reflection.WellKnown.IndexerPropertyGetterName, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
+      if (indexerGetter.Attributes.HasFlag(MethodAttributes.SpecialName)
+          && (indexerGetter.DeclaringType == WellKnownOrmTypes.Persistent || indexerGetter.DeclaringType == WellKnownOrmTypes.Entity))
+        return Expression.Convert(Expression.Call(Expression.Constant(owner), indexerGetter, new[] { Expression.Constant(entitySet.Field.Name) }), entitySet.Field.ValueType);
+
+      // old-fashion slow way, if something went wrong
+      var indexers = ownerType.GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
         .Where(p => p.GetIndexParameters().Any())
         .Select(p => p.GetGetMethod());
       return Expression.Convert(Expression.Call(Expression.Constant(owner),indexers.Single(), new []{Expression.Constant(entitySet.Field.Name)}), entitySet.Field.ValueType);
@@ -191,7 +200,7 @@ public static void TryAddConvarianceCast(ref Expression source, Type baseType)
     public static Type GetSequenceElementType(Type type)
     {
       var sequenceType = type.GetGenericInterface(WellKnownInterfaces.EnumerableOfT);
-      return sequenceType!=null ? sequenceType.GetGenericArguments()[0] : null;
+      return sequenceType?.GetGenericArguments()[0];
     }
 
     private static Expression BuildExpressionForFieldRecursivly(FieldInfo field, Expression parameter)
@@ -202,5 +211,9 @@ private static Expression BuildExpressionForFieldRecursivly(FieldInfo field, Exp
       }
       return Expression.Property(parameter, field.DeclaringField.UnderlyingProperty);
     }
+
+    private static bool IsOwnerWrapper(this Type type) =>
+      (type.MetadataToken ^ OwnerWrapper<int>.GenericDef.MetadataToken) == 0
+        && ReferenceEquals(type.Module, OwnerWrapper<int>.GenericDef.Module);
   }
 }

Orm/Xtensive.Orm/Orm/Linq/Rewriters/PersistentIndexerRewriter.cs

@@ -78,9 +78,9 @@ private Expression GetMemberExpression(MethodCallExpression mc)
       if (propertyInfo!=null)
         return Expression.MakeMemberAccess(mc.Object, propertyInfo);
 
-      var attributes = mc.Object.Type.GetCustomAttributes(WellKnownTypes.DefaultMemberAttribute, true);
-      var indexerPropertyName = ((DefaultMemberAttribute)attributes.Single()).MemberName;
-      var indexerProperty = mc.Object.Type.GetProperty(indexerPropertyName);
+      //var attributes = mc.Object.Type.GetCustomAttributes(WellKnownTypes.DefaultMemberAttribute, true);
+      //var indexerPropertyName = ((DefaultMemberAttribute)attributes.Single()).MemberName;
+      var indexerProperty = mc.Object.Type.GetProperty(Reflection.WellKnown.IndexerPropertyName);
       if (indexerProperty!=null)
         return Expression.MakeIndex(mc.Object, indexerProperty, new[] {Expression.Constant(name)});
       throw new InvalidOperationException(String.Format(Strings.ExFieldXNotFoundInTypeX, name, mc.Object.Type));
@@ -96,7 +96,7 @@ private bool IsIndexerAccessor(Expression expression)
         return false;
       }
       var method = methodCallExpression.Method;
-      return method.Name == "get_Item"
+      return method.Name == Reflection.WellKnown.IndexerPropertyGetterName
         && method.DeclaringType switch { var declaringType => declaringType == WellKnownOrmTypes.Persistent || declaringType == WellKnownOrmInterfaces.Entity }
         && context.Evaluator.CanBeEvaluated(methodCallExpression.Arguments[0]);
     }

Orm/Xtensive.Orm/Orm/Linq/Translator.Expressions.cs

@@ -983,7 +983,12 @@ private Expression VisitIndex(IndexExpression ie)
         }
       }
       var fieldInfo = typeInfo.Fields[evaluatedArgument];
-      return Expression.Convert(Expression.Call(objectExpression, objectExpression.Type.GetProperty("Item").GetGetMethod(), new[] {Expression.Constant(evaluatedArgument)}), fieldInfo.ValueType);
+      return Expression.Convert(
+        Expression.Call(
+          objectExpression,
+          objectExpression.Type.GetProperty(Reflection.WellKnown.IndexerPropertyName).GetGetMethod(),
+          new[] {Expression.Constant(evaluatedArgument)}),
+        fieldInfo.ValueType);
     }
 
     private static bool IsConditionalOrWellknown(Expression expression)
@@ -1054,9 +1059,7 @@ private IList<Expression> GetStructureFields(
           propertyAccessorExpression = Expression.MakeMemberAccess(Expression.Convert(expression, structureType), fieldExpression.UnderlyingProperty);
         }
         else {
-          var attributes = structureType.GetCustomAttributes(WellKnownTypes.DefaultMemberAttribute, true);
-          var indexerPropertyName = ((DefaultMemberAttribute)attributes.Single()).MemberName;
-          var methodInfo = structureType.GetProperty(indexerPropertyName).GetGetMethod();
+          var methodInfo = structureType.GetProperty(Reflection.WellKnown.IndexerPropertyName).GetGetMethod();
           propertyAccessorExpression = Expression.Call(Expression.Convert(expression, structureType), methodInfo, Expression.Constant(fieldExpression.Name));
         }
         var memberExpression = (Expression) Expression.Condition(

Orm/Xtensive.Orm/Reflection/WellKnown.cs

@@ -38,6 +38,11 @@ public static partial class WellKnown
     /// </summary>
     public const string IndexerPropertyName = "Item";
 
+    /// <summary>
+    /// Returns "get_Item"
+    /// </summary>
+    public const string IndexerPropertyGetterName = "get_Item";
+
     /// <summary>
     /// Returns "add_".
     /// </summary>