/// <summary>
/// Returns syntax for retrieving the value of this field, deep copying it if necessary.
/// </summary>
/// <param name="instance">The instance of the containing type.</param>
/// <param name="serializationContextExpression">The expression used to retrieve the serialization context.</param>
/// <param name="forceAvoidCopy">Whether or not to ensure that no copy of the field is made.</param>
/// <returns>Syntax for retrieving the value of this field.</returns>
public ExpressionSyntax GetGetter(ExpressionSyntax instance, ExpressionSyntax serializationContextExpression = null, bool forceAvoidCopy = false)
{
// Retrieve the value of the field.
var getValueExpression = this.GetValueExpression(instance);
// Avoid deep-copying the field if possible.
if (forceAvoidCopy || this.FieldInfo.FieldType.IsOrleansShallowCopyable())
{
// Return the value without deep-copying it.
return(getValueExpression);
}
// Addressable arguments must be converted to references before passing.
// IGrainObserver instances cannot be directly converted to references, therefore they are not included.
ExpressionSyntax deepCopyValueExpression;
if (typeof(IAddressable).IsAssignableFrom(this.FieldInfo.FieldType) &&
this.FieldInfo.FieldType.GetTypeInfo().IsInterface &&
!typeof(IGrainObserver).IsAssignableFrom(this.FieldInfo.FieldType))
{
var getAsReference = getValueExpression.Member(
(IAddressable grain) => grain.AsReference <IGrain>(),
this.FieldInfo.FieldType);
// If the value is not a GrainReference, convert it to a strongly-typed GrainReference.
// C#: (value == null || value is GrainReference) ? value : value.AsReference<TInterface>()
deepCopyValueExpression =
SF.ConditionalExpression(
SF.ParenthesizedExpression(
SF.BinaryExpression(
SyntaxKind.LogicalOrExpression,
SF.BinaryExpression(
SyntaxKind.EqualsExpression,
getValueExpression,
SF.LiteralExpression(SyntaxKind.NullLiteralExpression)),
SF.BinaryExpression(
SyntaxKind.IsExpression,
getValueExpression,
typeof(GrainReference).GetTypeSyntax()))),
getValueExpression,
SF.InvocationExpression(getAsReference));
}
else
{
deepCopyValueExpression = getValueExpression;
}
// Deep-copy the value.
Expression <Action> deepCopyInner = () => SerializationManager.DeepCopyInner(default(object), default(ICopyContext));
var typeSyntax = this.FieldInfo.FieldType.GetTypeSyntax();
return(SF.CastExpression(
typeSyntax,
deepCopyInner.Invoke()
.AddArgumentListArguments(
SF.Argument(deepCopyValueExpression),
SF.Argument(serializationContextExpression))));
}
private static ExpressionSyntax GetParameterForInvocation(ParameterInfo arg, int argIndex)
{
var argIdentifier = arg.GetOrCreateName(argIndex).ToIdentifierName();
// Addressable arguments must be converted to references before passing.
if (typeof(IAddressable).GetTypeInfo().IsAssignableFrom(arg.ParameterType) &&
arg.ParameterType.GetTypeInfo().IsInterface)
{
return
(SF.ConditionalExpression(
SF.BinaryExpression(SyntaxKind.IsExpression, argIdentifier, typeof(Grain).GetTypeSyntax()),
SF.InvocationExpression(argIdentifier.Member("AsReference", arg.ParameterType)),
argIdentifier));
}
return(argIdentifier);
}
