private static void CreateMethodDelegate(HandlerClassBuildingContext classContext)
{
const int implementationArgIndex = 1;
const int dataArgIndex = 2;
const int offsetArgIndex = 3;
var methodBuilder = classContext.Builder.DefineMethod("Handle",
MethodAttributes.Public | MethodAttributes.Final | MethodAttributes.HideBySig |
MethodAttributes.NewSlot | MethodAttributes.Virtual,
typeof(Task<byte[]>), new[] { typeof(object), typeof(byte[]), typeof(int) });
var il = new MyILGenerator(methodBuilder.GetILGenerator());
var emittingContext = new HandlerMethodEmittingContext(il, classContext.Fields);
var serviceDescriptionChain = classContext.ServiceDescriptionChain;
il.Ldarg(implementationArgIndex); // stack_0 = (TServiceImplementation) arg_1
il.Castclass(serviceDescriptionChain.First().Type);
for (int i = 0; i < serviceDescriptionChain.Count - 1; i++)
{
var current = serviceDescriptionChain[i];
var next = serviceDescriptionChain[i + 1];
il.Callvirt(current.Type.GetProperty(next.Name).GetGetMethod()); // stack_0 = stack_0.Property
}
var methodDescription = classContext.MethodDescription;
var genericArgumentMap = methodDescription.GenericParameters
.Zip(classContext.GenericTypeParameterBuilders, (p, a) => new KeyValuePair<string, Type>(p.Name, a))
.ToDictionary(x => x.Key, x => x.Value);
var parameterDescriptions = methodDescription.Parameters.Select(x => x.DeepSubstituteGenerics(genericArgumentMap)).ToArray();
var retvalType = methodDescription.ReturnType.DeepSubstituteGenerics(genericArgumentMap);
var allParameterCodecs = parameterDescriptions.Select((x, i) => new HandlerParameterCodec(emittingContext, x)).ToArray();
var requestParameterCodecs = allParameterCodecs.Where(x => x.IsRequestParameter).ToArray();
var responseParameterCodecs = allParameterCodecs.Where(x => x.IsResponseParameter).ToArray();
if (requestParameterCodecs.Any())
{
il.Ldarg(dataArgIndex); // remainingBytes = dataArray.Length - offset
il.Ldlen();
il.Ldarg(offsetArgIndex);
il.Sub();
il.Stloc(emittingContext.RemainingBytesVar);
var pinnedVar = il.PinArray(typeof(byte), 2); // var pinned dataPointer = pin(dataArray)
il.Ldloc(pinnedVar); // data = dataPointer + offset
il.Ldarg(offsetArgIndex);
il.Add();
il.Stloc(emittingContext.DataPointerVar);
}
foreach (var codec in allParameterCodecs)
codec.EmitDecodeAndPrepare();
// ReSharper disable CoVariantArrayConversion
var resolvedMethodInfo = classContext.GenericTypeParameterBuilders.Any()
? methodDescription.MethodInfo.MakeGenericMethod(classContext.GenericTypeParameterBuilders)
: methodDescription.MethodInfo;
il.Callvirt(resolvedMethodInfo); // stack_0 = stack_0.Method(stack_1, stack_2, ...)
// ReSharper restore CoVariantArrayConversion
switch (methodDescription.RemotingType)
{
case MethodRemotingType.Direct:
EmitProcessAndEncodeDirect(emittingContext, responseParameterCodecs, retvalType);
break;
case MethodRemotingType.AsyncVoid:
EmitProcessAndEncodeAsyncVoid(emittingContext);
break;
case MethodRemotingType.AsyncWithRetval:
EmitProcessAndEncodeAsyncWithRetval(classContext, emittingContext, retvalType.GetGenericArguments()[0]);
break;
default:
throw new ArgumentOutOfRangeException();
}
il.Ret();
}