internal Factory(DynamicAssembly ab)
{
this.assembly = ab;
this.OfProxies = new Proxies(this);
this.OfStubs = new Stubs(this);
this.Dynamic = new Dynamic(this);
}
public Func <TWrappedType, TState, TWrappedType> Create()
{
var tb = this.ab.Module.DefineType(Guid.NewGuid().ToString(), TypeAttributes.Class);
var abstractType = typeof(TWrappedType);
tb.AddInterfaceImplementation(abstractType);
var postEntryDelegateField = this.postEntry == null ? null : tb.DefineField(
nameof(this.postEntry),
this.postEntry.GetType(),
FieldAttributes.Private | FieldAttributes.Static);
var preExitDelegateField = this.preExit == null ? null : tb.DefineField(
nameof(this.preExit),
this.preExit.GetType(),
FieldAttributes.Private | FieldAttributes.Static);
var targetField = tb.DefineField(
"target",
abstractType,
FieldAttributes.InitOnly | FieldAttributes.Private);
var stateField = tb.DefineField(
"state",
typeof(TState),
FieldAttributes.InitOnly | FieldAttributes.Private);
{
var constructor = tb.DefineConstructor(
MethodAttributes.Public,
CallingConventions.HasThis,
new Type[] { targetField.FieldType, stateField.FieldType });
var il = constructor.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Call, typeof(object).GetConstructor(Type.EmptyTypes));
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Stfld, targetField);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldarg_2);
il.Emit(OpCodes.Stfld, stateField);
il.Emit(OpCodes.Ret);
}
this.ab.ImplementAbstractMethods(tb, abstractType, ImplementAsDecorator, false);
var typeInfo = tb.CreateTypeInfo();
var runtimePostEntryField = typeInfo.GetField(nameof(this.postEntry), BindingFlags.Static | BindingFlags.NonPublic);
runtimePostEntryField?.SetValue(typeInfo, this.postEntry);
var runtimePreExitField = typeInfo.GetField(nameof(this.preExit), BindingFlags.Static | BindingFlags.NonPublic);
runtimePreExitField?.SetValue(typeInfo, this.preExit);
return((target, state) => (TWrappedType)this.ab.ActivateInstance(typeInfo, target, state));
void ImplementAsDecorator(MethodInfo method, ILGenerator il)
{
il.DeclareLocal(typeof(object[]));
if (method.ReturnType != typeof(void))
{
il.DeclareLocal(method.ReturnType);
}
var parameters = method.GetParameters();
var length = parameters.Length;
if (postEntryDelegateField != null)
{
il.Emit(OpCodes.Ldc_I4, length);
il.Emit(OpCodes.Newarr, typeof(object));
for (int i = 0; i < length; ++i)
{
il.Emit(OpCodes.Dup);
il.Emit(OpCodes.Ldc_I4, i);
il.Emit(OpCodes.Ldarg, (short)(i + 1));
DynamicAssembly.TypeErase(il, parameters[i].ParameterType);
il.Emit(OpCodes.Stelem_Ref);
}
il.Emit(OpCodes.Stloc_0);
il.Emit(OpCodes.Ldsfld, postEntryDelegateField);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, targetField);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, stateField);
il.Emit(OpCodes.Ldloc_0);
il.EmitCall(OpCodes.Callvirt, postEntryDelegateField.FieldType.GetMethod("Invoke"), null);
for (int i = 0; i < length; ++i)
{
il.Emit(OpCodes.Ldloc_0);
il.Emit(OpCodes.Ldc_I4, i);
il.Emit(OpCodes.Ldelem_Ref);
DynamicAssembly.TypeRestore(il, parameters[i].ParameterType);
il.Emit(OpCodes.Starg, (short)(i + 1));
}
}
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, targetField);
DynamicAssembly.UnrollParameterLoading(il, 1, length);
il.EmitCall(OpCodes.Callvirt, method, null);
if (preExitDelegateField != null)
{
il.Emit(OpCodes.Stloc_1);
il.Emit(OpCodes.Ldsfld, preExitDelegateField);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, targetField);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, stateField);
il.Emit(OpCodes.Ldloc_1);
DynamicAssembly.TypeErase(il, method.ReturnType);
il.EmitCall(OpCodes.Callvirt, preExitDelegateField.FieldType.GetMethod("Invoke"), null);
DynamicAssembly.TypeRestore(il, method.ReturnType);
}
il.Emit(OpCodes.Ret);
}
}
internal InstantiatedStatefulBuilder(DynamicAssembly ab)
{
this.ab = ab;
}
internal InstantiatedStatelessBuilder(DynamicAssembly ab)
{
this.ab = ab;
this.builder = new InstantiatedStatefulBuilder <TWrappedType, object>(ab);
}
internal ProxyBuilder(DynamicAssembly ab)
{
this.ab = ab;
}
internal Proxies(Factory factory)
{
this.factory = factory;
this.ab = this.factory.Assembly;
}