private static ExpressionInfo <Func <int, int, int> > CreateSumExprInfo()
{
var aExp = ExpressionInfo.Parameter(typeof(int), "a");
var bExp = ExpressionInfo.Parameter(typeof(int), "b");
return(ExpressionInfo.Lambda <Func <int, int, int> >(
ExpressionInfo.Add(aExp, bExp), aExp, bExp));
}
public void Can_sum_with_ExprInfo()
{
var a = ExpressionInfo.Parameter(typeof(int), "a");
var b = ExpressionInfo.Parameter(typeof(int), "b");
var expr = ExpressionInfo.Lambda <Func <int, int, int> >(ExpressionInfo.Add(a, b), a, b);
var sumFunc = expr.CompileFast(true);
Assert.IsNotNull(sumFunc);
Assert.AreEqual(sumFunc(1, 3), 4);
}
/// <code>
/// rootContext
/// => behavior1.Invoke(rootContext,
/// context1 => behavior2.Invoke(context1,
/// ...
/// context{N} => behavior{N}.Invoke(context{N},
/// context{N+1} => TaskEx.Completed))
/// </code>
public static Delegate CreatePipelineExecutionExpression(this IBehavior[] behaviors, List <Expression> expressions = null)
{
Delegate lambdaExpression = null;
var behaviorCount = behaviors.Length - 1;
// We start from the end of the list know the lambda expressions deeper in the call stack in advance
for (var i = behaviorCount; i >= 0; i--)
{
var currentBehavior = behaviors[i];
var behaviorInterfaceType = currentBehavior.GetType().GetBehaviorInterface();
if (behaviorInterfaceType == null)
{
throw new InvalidOperationException("Behaviors must implement IBehavior<TInContext, TOutContext>");
}
// Select the method on the type which was implemented from the behavior interface.
var methodInfo = currentBehavior.GetType().GetInterfaceMap(behaviorInterfaceType).TargetMethods.FirstOrDefault();
if (methodInfo == null)
{
throw new InvalidOperationException("Behaviors must implement IBehavior<TInContext, TOutContext> and provide an invocation method.");
}
var genericArguments = behaviorInterfaceType.GetGenericArguments();
var inContextType = genericArguments[0];
var inContextParameter = ExpressionInfo.Parameter(inContextType, $"context{i}");
if (i == behaviorCount)
{
if (currentBehavior is IPipelineTerminator)
{
inContextType = typeof(PipelineTerminator <> .ITerminatingContext).MakeGenericType(inContextType);
}
var doneDelegate = CreateDoneDelegate(inContextType, i);
lambdaExpression = CreateBehaviorCallDelegate(currentBehavior, methodInfo, inContextParameter, doneDelegate, expressions);
continue;
}
lambdaExpression = CreateBehaviorCallDelegate(currentBehavior, methodInfo, inContextParameter, lambdaExpression, expressions);
}
return(lambdaExpression);
}
/// <code>
/// rootContext
/// => behavior1.Invoke(rootContext,
/// context1 => behavior2.Invoke(context1,
/// ...
/// context{N} => behavior{N}.Invoke(context{N},
/// context{N+1} => TaskEx.Completed))
/// </code>
public static Delegate CreateFastPipelineExecutionExpression(this IBehavior[] behaviors, List <ExpressionInfo> expressions = null)
{
Delegate lambdaExpression = null;
var length = behaviors.Length - 1;
// We start from the end of the list know the lambda expressions deeper in the call stack in advance
for (var i = length; i >= 0; i--)
{
var currentBehavior = behaviors[i];
var behaviorInterfaceType = currentBehavior.GetType().GetInterfaces().FirstOrDefault(t => t.GetGenericArguments().Length == 2 && t.FullName.StartsWith("NServiceBus.Pipeline.IBehavior"));
if (behaviorInterfaceType == null)
{
throw new InvalidOperationException("Behaviors must implement IBehavior<TInContext, TOutContext>");
}
var methodInfo = behaviorInterfaceType.GetMethods().FirstOrDefault();
if (methodInfo == null)
{
throw new InvalidOperationException("Behaviors must implement IBehavior<TInContext, TOutContext> and provide an invocation method.");
}
var genericArguments = behaviorInterfaceType.GetGenericArguments();
var inContextType = genericArguments[0];
var inContextParameter = ExpressionInfo.Parameter(inContextType, $"context{i}");
if (i == length)
{
if (currentBehavior is IPipelineTerminator)
{
inContextType = typeof(PipelineTerminator <> .ITerminatingContext).MakeGenericType(inContextType);
}
var doneDelegate = CreateDoneDelegate(inContextType, i);
lambdaExpression = CreateBehaviorCallDelegate(currentBehavior, methodInfo, inContextParameter, doneDelegate, expressions);
continue;
}
lambdaExpression = CreateBehaviorCallDelegate(currentBehavior, methodInfo, inContextParameter, lambdaExpression, expressions);
}
return(lambdaExpression);
}
/// <code>
/// context{i} => return TaskEx.CompletedTask;
/// </code>>
static Delegate CreateDoneDelegate(Type inContextType, int i)
{
var innerContextParam = ExpressionInfo.Parameter(inContextType, $"context{i + 1}");
return(ExpressionInfo.Lambda(ExpressionInfo.Constant(Task.CompletedTask), innerContextParam).CompileFast());
}