/// <summary>
/// Generates <see cref="GenericMethodInvoker"/> fields for the generic methods in <paramref name="grainType"/>.
/// </summary>
/// <param name="grainType">The grain type.</param>
/// <returns>The generated fields.</returns>
private static MemberDeclarationSyntax[] GenerateGenericInvokerFields(Type grainType)
{
var methods = GrainInterfaceUtils.GetMethods(grainType);
var result = new List <MemberDeclarationSyntax>();
foreach (var method in methods)
{
if (!method.IsGenericMethodDefinition)
{
continue;
}
result.Add(GenerateGenericInvokerField(method));
}
return(result.ToArray());
}
/// <summary>
/// Generates invoker methods.
/// </summary>
/// <param name="grainType">The grain type.</param>
/// <param name="onEncounteredType">
/// The callback which is invoked when a type is encountered.
/// </param>
/// <returns>Invoker methods for the provided grain type.</returns>
private static MemberDeclarationSyntax[] GenerateInvokeMethods(Type grainType, Action <Type> onEncounteredType)
{
var baseReference = SF.BaseExpression();
var methods = GrainInterfaceUtils.GetMethods(grainType);
var members = new List <MemberDeclarationSyntax>();
foreach (var method in methods)
{
onEncounteredType(method.ReturnType);
var methodId = GrainInterfaceUtils.ComputeMethodId(method);
var methodIdArgument =
SF.Argument(SF.LiteralExpression(SyntaxKind.NumericLiteralExpression, SF.Literal(methodId)));
// Construct a new object array from all method arguments.
var parameters = method.GetParameters();
var body = new List <StatementSyntax>();
foreach (var parameter in parameters)
{
onEncounteredType(parameter.ParameterType);
if (typeof(IGrainObserver).GetTypeInfo().IsAssignableFrom(parameter.ParameterType))
{
body.Add(
SF.ExpressionStatement(
CheckGrainObserverParamInternalExpression.Invoke()
.AddArgumentListArguments(SF.Argument(parameter.Name.ToIdentifierName()))));
}
}
// Get the parameters argument value.
ExpressionSyntax args;
if (parameters.Length == 0)
{
args = SF.LiteralExpression(SyntaxKind.NullLiteralExpression);
}
else
{
args =
SF.ArrayCreationExpression(typeof(object).GetArrayTypeSyntax())
.WithInitializer(
SF.InitializerExpression(SyntaxKind.ArrayInitializerExpression)
.AddExpressions(parameters.Select(GetParameterForInvocation).ToArray()));
}
var options = GetInvokeOptions(method);
// Construct the invocation call.
if (method.ReturnType == typeof(void))
{
var invocation = SF.InvocationExpression(baseReference.Member("InvokeOneWayMethod"))
.AddArgumentListArguments(methodIdArgument)
.AddArgumentListArguments(SF.Argument(args));
if (options != null)
{
invocation = invocation.AddArgumentListArguments(options);
}
body.Add(SF.ExpressionStatement(invocation));
}
else
{
var returnType = method.ReturnType == typeof(Task)
? typeof(object)
: method.ReturnType.GenericTypeArguments[0];
var invocation =
SF.InvocationExpression(baseReference.Member("InvokeMethodAsync", returnType))
.AddArgumentListArguments(methodIdArgument)
.AddArgumentListArguments(SF.Argument(args));
if (options != null)
{
invocation = invocation.AddArgumentListArguments(options);
}
body.Add(SF.ReturnStatement(invocation));
}
members.Add(method.GetDeclarationSyntax().AddBodyStatements(body.ToArray()));
}
return(members.ToArray());
}
/// <summary>
/// Generates invoker methods.
/// </summary>
/// <param name="grainType">The grain type.</param>
/// <param name="onEncounteredType">
/// The callback which is invoked when a type is encountered.
/// </param>
/// <returns>Invoker methods for the provided grain type.</returns>
private static MemberDeclarationSyntax[] GenerateInvokeMethods(Type grainType, Action <Type> onEncounteredType)
{
var baseReference = SF.BaseExpression();
var methods = GrainInterfaceUtils.GetMethods(grainType);
var members = new List <MemberDeclarationSyntax>();
foreach (var method in methods)
{
onEncounteredType(method.ReturnType);
var methodId = GrainInterfaceUtils.ComputeMethodId(method);
var methodIdArgument =
SF.Argument(SF.LiteralExpression(SyntaxKind.NumericLiteralExpression, SF.Literal(methodId)));
// Construct a new object array from all method arguments.
var parameters = method.GetParameters();
var body = new List <StatementSyntax>();
foreach (var parameter in parameters)
{
onEncounteredType(parameter.ParameterType);
if (typeof(IGrainObserver).IsAssignableFrom(parameter.ParameterType))
{
body.Add(
SF.ExpressionStatement(
CheckGrainObserverParamInternalExpression.Invoke()
.AddArgumentListArguments(SF.Argument(parameter.Name.ToIdentifierName()))));
}
}
// Get the parameters argument value.
ExpressionSyntax args;
if (method.IsGenericMethodDefinition)
{
// Create an arguments array which includes the method's type parameters followed by the method's parameter list.
var allParameters = new List <ExpressionSyntax>();
foreach (var typeParameter in method.GetGenericArguments())
{
allParameters.Add(SF.TypeOfExpression(typeParameter.GetTypeSyntax()));
}
allParameters.AddRange(parameters.Select(GetParameterForInvocation));
args =
SF.ArrayCreationExpression(typeof(object).GetArrayTypeSyntax())
.WithInitializer(
SF.InitializerExpression(SyntaxKind.ArrayInitializerExpression)
.AddExpressions(allParameters.ToArray()));
}
else if (parameters.Length == 0)
{
args = SF.LiteralExpression(SyntaxKind.NullLiteralExpression);
}
else
{
args =
SF.ArrayCreationExpression(typeof(object).GetArrayTypeSyntax())
.WithInitializer(
SF.InitializerExpression(SyntaxKind.ArrayInitializerExpression)
.AddExpressions(parameters.Select(GetParameterForInvocation).ToArray()));
}
var options = GetInvokeOptions(method);
// Construct the invocation call.
var isOneWayTask = method.GetCustomAttribute <OneWayAttribute>() != null;
if (method.ReturnType == typeof(void) || isOneWayTask)
{
var invocation = SF.InvocationExpression(baseReference.Member("InvokeOneWayMethod"))
.AddArgumentListArguments(methodIdArgument)
.AddArgumentListArguments(SF.Argument(args));
if (options != null)
{
invocation = invocation.AddArgumentListArguments(options);
}
body.Add(SF.ExpressionStatement(invocation));
if (isOneWayTask)
{
if (method.ReturnType != typeof(Task))
{
throw new CodeGenerationException(
$"Method {grainType.GetParseableName()}.{method.Name} is marked with [{nameof(OneWayAttribute)}], " +
$"but has a return type which is not assignable from {typeof(Task)}");
}
var done = typeof(Task).GetNameSyntax(true).Member((object _) => Task.CompletedTask);
body.Add(SF.ReturnStatement(done));
}
}
else
{
var returnType = method.ReturnType == typeof(Task)
? typeof(object)
: method.ReturnType.GenericTypeArguments[0];
var invocation =
SF.InvocationExpression(baseReference.Member("InvokeMethodAsync", returnType))
.AddArgumentListArguments(methodIdArgument)
.AddArgumentListArguments(SF.Argument(args));
if (options != null)
{
invocation = invocation.AddArgumentListArguments(options);
}
ExpressionSyntax returnContent = invocation;
if (method.ReturnType.IsGenericType &&
method.ReturnType.GetGenericTypeDefinition().FullName == "System.Threading.Tasks.ValueTask`1")
{
// Wrapping invocation expression with initialization of ValueTask (e.g. new ValueTask<int>(base.InvokeMethod()))
returnContent =
SF.ObjectCreationExpression(method.ReturnType.GetTypeSyntax())
.AddArgumentListArguments(SF.Argument(SF.ExpressionStatement(invocation).Expression));
}
body.Add(SF.ReturnStatement(returnContent));
}
members.Add(method.GetDeclarationSyntax().AddBodyStatements(body.ToArray()));
}
return(members.ToArray());
}
/// <summary>
/// Generates switch cases for the provided grain type.
/// </summary>
/// <param name="grainType">
/// The grain type.
/// </param>
/// <param name="methodIdArgument">
/// The method id argument, which is used to select the correct switch label.
/// </param>
/// <param name="generateMethodHandler">
/// The function used to generate switch block statements for each method.
/// </param>
/// <returns>
/// The switch cases for the provided grain type.
/// </returns>
public static SwitchSectionSyntax[] GenerateGrainInterfaceAndMethodSwitch(
Type grainType,
ExpressionSyntax methodIdArgument,
Func <MethodInfo, StatementSyntax[]> generateMethodHandler)
{
var interfaces = GrainInterfaceUtils.GetRemoteInterfaces(grainType);
interfaces[GrainInterfaceUtils.GetGrainInterfaceId(grainType)] = grainType;
// Switch on interface id.
var interfaceCases = new List <SwitchSectionSyntax>();
foreach (var @interface in interfaces)
{
var interfaceType = @interface.Value;
var interfaceId = @interface.Key;
var methods = GrainInterfaceUtils.GetMethods(interfaceType);
var methodCases = new List <SwitchSectionSyntax>();
// Switch on method id.
foreach (var method in methods)
{
// Generate switch case.
var methodId = GrainInterfaceUtils.ComputeMethodId(method);
var methodType = method;
// Generate the switch label for this interface id.
var methodIdSwitchLabel =
SF.CaseSwitchLabel(
SF.LiteralExpression(SyntaxKind.NumericLiteralExpression, SF.Literal(methodId)));
// Generate the switch body.
var methodInvokeStatement = generateMethodHandler(methodType);
methodCases.Add(
SF.SwitchSection().AddLabels(methodIdSwitchLabel).AddStatements(methodInvokeStatement));
}
// Generate the switch label for this interface id.
var interfaceIdSwitchLabel =
SF.CaseSwitchLabel(
SF.LiteralExpression(SyntaxKind.NumericLiteralExpression, SF.Literal(interfaceId)));
// Generate the default case, which will throw a NotImplementedException.
var errorMessage = SF.BinaryExpression(
SyntaxKind.AddExpression,
"interfaceId=".GetLiteralExpression(),
SF.BinaryExpression(
SyntaxKind.AddExpression,
SF.LiteralExpression(SyntaxKind.NumericLiteralExpression, SF.Literal(interfaceId)),
SF.BinaryExpression(
SyntaxKind.AddExpression,
",methodId=".GetLiteralExpression(),
methodIdArgument)));
var throwStatement =
SF.ThrowStatement(
SF.ObjectCreationExpression(typeof(NotImplementedException).GetTypeSyntax())
.AddArgumentListArguments(SF.Argument(errorMessage)));
var defaultCase = SF.SwitchSection().AddLabels(SF.DefaultSwitchLabel()).AddStatements(throwStatement);
// Generate switch statements for the methods in this interface.
var methodSwitchStatements =
SF.SwitchStatement(methodIdArgument).AddSections(methodCases.ToArray()).AddSections(defaultCase);
// Generate the switch section for this interface.
interfaceCases.Add(
SF.SwitchSection().AddLabels(interfaceIdSwitchLabel).AddStatements(methodSwitchStatements));
}
return(interfaceCases.ToArray());
}