public override Expression Visit(Expression node)
{
switch (node)
{
case DefaultIfEmptyExpression defaultIfEmptyExpression:
{
return(Expression.Condition(
test: Expression.Call(
readerParameter,
isDBNullMethodInfo,
Expression.Constant(readerIndex++)),
ifTrue: Expression.Default(defaultIfEmptyExpression.Type),
ifFalse: Visit(defaultIfEmptyExpression.Expression)));
}
case PolymorphicExpression polymorphicExpression:
{
var variables = new List <ParameterExpression>();
var expressions = new List <Expression>();
var rowValue = polymorphicExpression.Row;
var rowVariable = Expression.Variable(rowValue.Type, "row");
var rowParameterExpansion = (Expression)rowVariable;
if (rowValue is ExtraPropertiesExpression extraPropertiesExpression)
{
extraPropertiesExpression = VisitAndConvert(extraPropertiesExpression, nameof(Visit));
var properties = new List <Expression>();
for (var i = 0; i < extraPropertiesExpression.Names.Count; i++)
{
var propertyName = extraPropertiesExpression.Names[i];
var propertyValue = extraPropertiesExpression.Properties[i];
var propertyVariable = Expression.Variable(propertyValue.Type, propertyName);
variables.Add(propertyVariable);
properties.Add(propertyVariable);
expressions.Add(Expression.Assign(propertyVariable, propertyValue));
}
rowValue = Visit(extraPropertiesExpression.Expression);
rowVariable = Expression.Variable(rowValue.Type, "row");
rowParameterExpansion = extraPropertiesExpression.Update(rowVariable, properties);
}
else
{
rowValue = Visit(rowValue);
}
variables.Add(rowVariable);
expressions.Add(Expression.Assign(rowVariable, rowValue));
var useSwitchBlock
= polymorphicExpression.Descriptors
.All(d => d.Test.Body.NodeType == ExpressionType.Equal &&
((BinaryExpression)d.Test.Body).Right is ConstantExpression constant &&
constant.Type.IsConstantLiteralType());
if (useSwitchBlock)
{
var result = Expression.Parameter(polymorphicExpression.Type);
var cases = new SwitchCase[polymorphicExpression.Descriptors.Count()];
//var breakTarget = Expression.Label();
var i = 0;
foreach (var descriptor in polymorphicExpression.Descriptors)
{
var materializer = descriptor.Materializer.ExpandParameters(rowParameterExpansion);
var expansion = Expression.Convert(materializer, polymorphicExpression.Type);
var assignment = Expression.Assign(result, expansion);
var testValue = ((BinaryExpression)descriptor.Test.Body).Right;
var body = assignment; //Expression.Block(assignment, Expression.Break(breakTarget));
cases[i] = Expression.SwitchCase(body, testValue);
i++;
}
variables.Add(result);
expressions.Add(
Expression.Switch(
((BinaryExpression)polymorphicExpression.Descriptors.First().Test.ExpandParameters(rowParameterExpansion)).Left,
Expression.Assign(result, Expression.Default(polymorphicExpression.Type)),
cases));
//expressions.Add(Expression.Label(breakTarget));
expressions.Add(result);
}
else
{
var result = Expression.Default(polymorphicExpression.Type) as Expression;
foreach (var descriptor in polymorphicExpression.Descriptors)
{
var test = descriptor.Test.ExpandParameters(rowParameterExpansion);
var materializer = descriptor.Materializer.ExpandParameters(rowParameterExpansion);
var expansion = Expression.Convert(materializer, polymorphicExpression.Type);
result = Expression.Condition(test, expansion, result, polymorphicExpression.Type);
}
expressions.Add(result);
}
return(Expression.Block(variables, expressions));
}
default:
{
var visited = base.Visit(node);
if (visited is ExtraPropertiesExpression || visited is NewExpression)
{
return(visited);
}
var parts = GetNameParts().ToArray();
var identifier = $"Materialize_";
if (parts.Length == 0)
{
identifier += "$root";
}
else if (parts.Length == 1)
{
identifier += parts[0];
}
else
{
identifier += $"{parts.First()}_{{{parts.Length - 2}}}_{parts.Last()}";
}
if (identifierCounts.TryGetValue(identifier, out var count))
{
identifierCounts[identifier] = count + 1;
identifier += $"_{count}";
}
else
{
identifierCounts[identifier] = 1;
identifier += "_0";
}
return(MaterializationUtilities.Invoke(visited, identifier));
}
}
}
public override Expression Visit(Expression node)
{
switch (node)
{
case EntityMaterializationExpression entityMaterializationExpression:
{
var entityVariable = Expression.Variable(node.Type, "entity");
var shadowPropertiesVariable = Expression.Variable(typeof(object[]), "shadow");
var entityType = entityMaterializationExpression.EntityType;
var materializer = Visit(entityMaterializationExpression.Expression);
var getEntityMethodInfo = default(MethodInfo);
switch (entityMaterializationExpression.IdentityMapMode)
{
case IdentityMapMode.StateManager:
{
getEntityMethodInfo = EntityTrackingHelper.GetEntityUsingStateManagerMethodInfo;
break;
}
case IdentityMapMode.IdentityMap:
default:
{
getEntityMethodInfo = EntityTrackingHelper.GetEntityUsingIdentityMapMethodInfo;
break;
}
}
var shadowPropertiesExpression = (Expression)Expression.Constant(new object[0]);
var shadowProperties = entityMaterializationExpression.ShadowProperties;
if (!shadowProperties.IsDefaultOrEmpty)
{
var values
= Enumerable
.Repeat(Expression.Constant(null), entityType.PropertyCount())
.Cast <Expression>()
.ToArray();
for (var i = 0; i < shadowProperties.Length; i++)
{
values[shadowProperties[i].GetIndex()]
= Expression.Convert(
entityMaterializationExpression.Properties[i],
typeof(object));
}
shadowPropertiesExpression = Expression.NewArrayInit(typeof(object), values);
}
var result
= Expression.Block(
variables: new ParameterExpression[]
{
entityVariable,
shadowPropertiesVariable,
},
expressions: new Expression[]
{
Expression.Assign(
shadowPropertiesVariable,
shadowPropertiesExpression),
Expression.Assign(
entityVariable,
new CollectionNavigationFixupExpressionVisitor(model)
.Visit(materializer)),
Expression.Convert(
Expression.Call(
getEntityMethodInfo,
Expression.Convert(executionContextParameter, typeof(EFCoreDbCommandExecutor)),
Expression.Constant(entityType),
entityMaterializationExpression.KeyExpression
.UnwrapLambda()
.ExpandParameters(entityVariable, shadowPropertiesVariable),
entityVariable,
shadowPropertiesVariable,
Expression.Constant(entityMaterializationExpression.IncludedNavigations.ToList())),
node.Type)
});
var identifier = $"MaterializeEntity_{entityType.DisplayName()}";
if (identifierCounts.TryGetValue(identifier, out var count))
{
identifierCounts[identifier] = count + 1;
identifier += $"_{count}";
}
else
{
identifierCounts[identifier] = 1;
identifier += "_0";
}
return(MaterializationUtilities.Invoke(result, identifier));
}
default:
{
return(base.Visit(node));
}
}
}
