private static DynamicMethod BuildDispatchingMethod(IActor handler, IStructSizeCounter counter,
Func <Type, int> messageIdGetter)
{
var handlerType = handler.GetType();
var handleMethods = ActorRegistry.GetHandleMethods(handlerType)
.ToDictionary(m => messageIdGetter(m.GetParameters()[1].ParameterType.GetElementType()), m => m)
.OrderBy(kvp => kvp.Key)
.ToArray();
var dm = new DynamicMethod("ReadMessagesFor_" + handlerType.Namespace.Replace(".", "_") + handlerType.Name,
typeof(void), new[] { typeof(MessageReader), typeof(int), typeof(ByteChunk) },
handlerType.Assembly.Modules.First(), true);
var actorField = typeof(MessageReader).GetFields(BindingFlags.NonPublic | BindingFlags.Instance)
.Single(fi => fi.FieldType == typeof(IActor));
var il = dm.GetILGenerator();
// push handler
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, actorField);
il.Emit(OpCodes.Castclass, handlerType);
var endLbl = il.DefineLabel();
// dispatch
foreach (var method in handleMethods)
{
var lbl = il.DefineLabel();
il.Emit(OpCodes.Ldarg_1); // messageTypeId
il.Emit(OpCodes.Ldc_I4, method.Key);
il.Emit(OpCodes.Ceq);
il.Emit(OpCodes.Brfalse_S, lbl);
// push envelope
il.Emit(OpCodes.Ldarg_2);
il.Emit(OpCodes.Ldfld, typeof(ByteChunk).GetField("Pointer"));
//var messageType = method.Value.GetParameters()[1].ParameterType.GetElementType();
//il.Emit(OpCodes.Ldc_I4, (int)Marshal.OffsetOf(messageType, Envelope.FieldName));
//il.Emit(OpCodes.Add);
// push message
il.Emit(OpCodes.Ldarg_2);
il.Emit(OpCodes.Ldfld, typeof(ByteChunk).GetField("Pointer"));
il.EmitCall(OpCodes.Callvirt, method.Value, null);
il.Emit(OpCodes.Br_S, endLbl);
il.MarkLabel(lbl);
}
// nothing was called, pop
il.Emit(OpCodes.Pop);
// end label
il.MarkLabel(endLbl);
il.Emit(OpCodes.Ret);
return(dm);
}
internal void Init(ActorId owner, ActorRegistry registry, int throwAfterNTrials, IMessageWriter writer)
{
if (_sealed)
{
throw new InvalidOperationException("The bus has been already initialized");
}
_owner = owner;
_registry = registry;
_throwAfterNTrials = throwAfterNTrials;
_writer = writer;
_sealed = true;
}
/// <summary>
/// Gets all the message types handled by the given <paramref name="handlerType"/>
/// </summary>
private static IEnumerable <Type> GetHandledMessageTypes(Type handlerType)
{
return
(ActorRegistry.GetHandleMethods(handlerType)
.Select(m => m.GetParameters()[1].ParameterType.GetElementType()));
}
public Bus(ActorId owner, ActorRegistry registry, int throwAfterNTrials, IMessageWriter writer)
{
Init(owner, registry, throwAfterNTrials, writer);
}
