From 43ad219b75740ef71ad9bad496b00c076182619b Mon Sep 17 00:00:00 2001 From: Shockah Date: Wed, 9 Feb 2022 20:07:01 +0100 Subject: support proxying return values in API proxies --- .../Framework/Reflection/InterfaceProxyBuilder.cs | 183 ++++++++++++++++----- .../Framework/Reflection/InterfaceProxyFactory.cs | 30 +++- .../Framework/Reflection/InterfaceProxyGlue.cs | 18 ++ 3 files changed, 186 insertions(+), 45 deletions(-) create mode 100644 src/SMAPI/Framework/Reflection/InterfaceProxyGlue.cs (limited to 'src/SMAPI') diff --git a/src/SMAPI/Framework/Reflection/InterfaceProxyBuilder.cs b/src/SMAPI/Framework/Reflection/InterfaceProxyBuilder.cs index 5ae96dff..d8b066bd 100644 --- a/src/SMAPI/Framework/Reflection/InterfaceProxyBuilder.cs +++ b/src/SMAPI/Framework/Reflection/InterfaceProxyBuilder.cs @@ -1,13 +1,22 @@ using System; +using System.Collections.Generic; using System.Linq; using System.Reflection; using System.Reflection.Emit; +using HarmonyLib; namespace StardewModdingAPI.Framework.Reflection { /// Generates a proxy class to access a mod API through an arbitrary interface. internal class InterfaceProxyBuilder { + /********* + ** Consts + *********/ + private static readonly string TargetFieldName = "__Target"; + private static readonly string GlueFieldName = "__Glue"; + private static readonly MethodInfo CreateInstanceForProxyTypeNameMethod = typeof(InterfaceProxyGlue).GetMethod(nameof(InterfaceProxyGlue.CreateInstanceForProxyTypeName), new Type[] { typeof(string), typeof(object) }); + /********* ** Fields *********/ @@ -22,11 +31,14 @@ namespace StardewModdingAPI.Framework.Reflection ** Public methods *********/ /// Construct an instance. + /// The that requested to build a proxy. /// The type name to generate. /// The CLR module in which to create proxy classes. /// The interface type to implement. /// The target type. - public InterfaceProxyBuilder(string name, ModuleBuilder moduleBuilder, Type interfaceType, Type targetType) + /// The unique ID of the mod consuming the API. + /// The unique ID of the mod providing the API. + public InterfaceProxyBuilder(InterfaceProxyFactory factory, string name, ModuleBuilder moduleBuilder, Type interfaceType, Type targetType, string sourceModID, string targetModID) { // validate if (name == null) @@ -38,12 +50,13 @@ namespace StardewModdingAPI.Framework.Reflection TypeBuilder proxyBuilder = moduleBuilder.DefineType(name, TypeAttributes.Public | TypeAttributes.Class); proxyBuilder.AddInterfaceImplementation(interfaceType); - // create field to store target instance - FieldBuilder targetField = proxyBuilder.DefineField("__Target", targetType, FieldAttributes.Private); + // create fields to store target instance and proxy factory + FieldBuilder targetField = proxyBuilder.DefineField(TargetFieldName, targetType, FieldAttributes.Private); + FieldBuilder glueField = proxyBuilder.DefineField(GlueFieldName, typeof(InterfaceProxyGlue), FieldAttributes.Private); - // create constructor which accepts target instance and sets field + // create constructor which accepts target instance + factory, and sets fields { - ConstructorBuilder constructor = proxyBuilder.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard | CallingConventions.HasThis, new[] { targetType }); + ConstructorBuilder constructor = proxyBuilder.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard | CallingConventions.HasThis, new[] { targetType, typeof(InterfaceProxyGlue) }); ILGenerator il = constructor.GetILGenerator(); il.Emit(OpCodes.Ldarg_0); // this @@ -52,6 +65,9 @@ namespace StardewModdingAPI.Framework.Reflection il.Emit(OpCodes.Ldarg_0); // this il.Emit(OpCodes.Ldarg_1); // load argument il.Emit(OpCodes.Stfld, targetField); // set field to loaded argument + il.Emit(OpCodes.Ldarg_0); // this + il.Emit(OpCodes.Ldarg_2); // load argument + il.Emit(OpCodes.Stfld, glueField); // set field to loaded argument il.Emit(OpCodes.Ret); } @@ -65,15 +81,20 @@ namespace StardewModdingAPI.Framework.Reflection } } - bool AreTypesMatching(Type targetType, Type proxyType, MethodTypeMatchingPart part) + MatchingTypesResult AreTypesMatching(Type targetType, Type proxyType, MethodTypeMatchingPart part) { var typeA = part == MethodTypeMatchingPart.Parameter ? targetType : proxyType; var typeB = part == MethodTypeMatchingPart.Parameter ? proxyType : targetType; if (typeA.IsGenericMethodParameter != typeB.IsGenericMethodParameter) - return false; + return MatchingTypesResult.False; // TODO: decide if "assignable" checking is desired (instead of just 1:1 type equality) - return typeA.IsGenericMethodParameter ? typeA.GenericParameterPosition == typeB.GenericParameterPosition : typeA.IsAssignableFrom(typeB); + if (typeA.IsGenericMethodParameter ? typeA.GenericParameterPosition == typeB.GenericParameterPosition : typeA.IsAssignableFrom(typeB)) + return MatchingTypesResult.True; + + if (!proxyType.IsGenericMethodParameter && proxyType.IsInterface && proxyType.Assembly == interfaceType.Assembly) + return MatchingTypesResult.IfProxied; + return MatchingTypesResult.False; } // proxy methods @@ -81,30 +102,61 @@ namespace StardewModdingAPI.Framework.Reflection { var proxyMethodParameters = proxyMethod.GetParameters(); var proxyMethodGenericArguments = proxyMethod.GetGenericArguments(); - var targetMethod = allTargetMethods.Where(m => + + foreach (MethodInfo targetMethod in allTargetMethods) { - if (m.Name != proxyMethod.Name) - return false; + // checking if `targetMethod` matches `proxyMethod` - if (m.GetGenericArguments().Length != proxyMethodGenericArguments.Length) - return false; - if (!AreTypesMatching(m.ReturnType, proxyMethod.ReturnType, MethodTypeMatchingPart.ReturnType)) - return false; + if (targetMethod.Name != proxyMethod.Name) + continue; + if (targetMethod.GetGenericArguments().Length != proxyMethodGenericArguments.Length) + continue; + var positionsToProxy = new HashSet(); // null = return type; anything else = parameter position + + switch (AreTypesMatching(targetMethod.ReturnType, proxyMethod.ReturnType, MethodTypeMatchingPart.ReturnType)) + { + case MatchingTypesResult.False: + continue; + case MatchingTypesResult.True: + break; + case MatchingTypesResult.IfProxied: + positionsToProxy.Add(null); + break; + } - var mParameters = m.GetParameters(); - if (m.GetParameters().Length != proxyMethodParameters.Length) - return false; + var mParameters = targetMethod.GetParameters(); + if (mParameters.Length != proxyMethodParameters.Length) + continue; for (int i = 0; i < mParameters.Length; i++) { - if (!AreTypesMatching(mParameters[i].ParameterType, proxyMethodParameters[i].ParameterType, MethodTypeMatchingPart.Parameter)) - return false; + switch (AreTypesMatching(mParameters[i].ParameterType, proxyMethodParameters[i].ParameterType, MethodTypeMatchingPart.Parameter)) + { + case MatchingTypesResult.False: + goto targetMethodLoopContinue; + case MatchingTypesResult.True: + break; + case MatchingTypesResult.IfProxied: + if (proxyMethodParameters[i].IsOut) + { + positionsToProxy.Add(i); + break; + } + else + { + goto targetMethodLoopContinue; + } + } } - return true; - }).FirstOrDefault(); - if (targetMethod == null) - throw new InvalidOperationException($"The {interfaceType.FullName} interface defines method {proxyMethod.Name} which doesn't exist in the API."); - this.ProxyMethod(proxyBuilder, proxyMethod, targetMethod, targetField); + // method matched; proxying + + this.ProxyMethod(factory, proxyBuilder, proxyMethod, targetMethod, targetField, glueField, positionsToProxy, sourceModID, targetModID); + goto proxyMethodLoopContinue; + targetMethodLoopContinue:; + } + + throw new InvalidOperationException($"The {interfaceType.FullName} interface defines method {proxyMethod.Name} which doesn't exist in the API."); + proxyMethodLoopContinue:; } // save info @@ -114,12 +166,13 @@ namespace StardewModdingAPI.Framework.Reflection /// Create an instance of the proxy for a target instance. /// The target instance. - public object CreateInstance(object targetInstance) + /// The that requested to build a proxy. + public object CreateInstance(object targetInstance, InterfaceProxyFactory factory) { - ConstructorInfo constructor = this.ProxyType.GetConstructor(new[] { this.TargetType }); + ConstructorInfo constructor = this.ProxyType.GetConstructor(new[] { this.TargetType, typeof(InterfaceProxyGlue) }); if (constructor == null) throw new InvalidOperationException($"Couldn't find the constructor for generated proxy type '{this.ProxyType.Name}'."); // should never happen - return constructor.Invoke(new[] { targetInstance }); + return constructor.Invoke(new[] { targetInstance, new InterfaceProxyGlue(factory) }); } @@ -127,11 +180,16 @@ namespace StardewModdingAPI.Framework.Reflection ** Private methods *********/ /// Define a method which proxies access to a method on the target. + /// The that requested to build a proxy. /// The proxy type being generated. /// The proxy method. /// The target method. /// The proxy field containing the API instance. - private void ProxyMethod(TypeBuilder proxyBuilder, MethodInfo proxy, MethodInfo target, FieldBuilder instanceField) + /// The proxy field containing an . + /// Parameter type positions (or null for the return type) for which types should also be proxied. + /// The unique ID of the mod consuming the API. + /// The unique ID of the mod providing the API. + private void ProxyMethod(InterfaceProxyFactory factory, TypeBuilder proxyBuilder, MethodInfo proxy, MethodInfo target, FieldBuilder instanceField, FieldBuilder glueField, ISet positionsToProxy, string sourceModID, string targetModID) { MethodBuilder methodBuilder = proxyBuilder.DefineMethod(proxy.Name, MethodAttributes.Public | MethodAttributes.Final | MethodAttributes.Virtual); @@ -143,7 +201,8 @@ namespace StardewModdingAPI.Framework.Reflection genericTypeParameterBuilders[i].SetGenericParameterAttributes(proxyGenericArguments[i].GenericParameterAttributes); // set up return type - methodBuilder.SetReturnType(proxy.ReturnType.IsGenericMethodParameter ? genericTypeParameterBuilders[proxy.ReturnType.GenericParameterPosition] : proxy.ReturnType); + Type returnType = proxy.ReturnType.IsGenericMethodParameter ? genericTypeParameterBuilders[proxy.ReturnType.GenericParameterPosition] : proxy.ReturnType; + methodBuilder.SetReturnType(returnType); // set up parameters Type[] argTypes = proxy.GetParameters() @@ -152,18 +211,62 @@ namespace StardewModdingAPI.Framework.Reflection .ToArray(); methodBuilder.SetParameters(argTypes); + // proxy additional types + string returnValueProxyTypeName = null; + string[] parameterProxyTypeNames = new string[argTypes.Length]; + if (positionsToProxy.Count > 0) + { + var targetParameters = target.GetParameters(); + foreach (int? position in positionsToProxy) + { + // we don't check for generics here, because earlier code does and generic positions won't end up here + if (position == null) // it's the return type + { + var builder = factory.ObtainBuilder(target.ReturnType, proxy.ReturnType, sourceModID, targetModID); + returnType = proxy.ReturnType; + returnValueProxyTypeName = builder.ProxyType.FullName; + } + else // it's one of the parameters + { + var builder = factory.ObtainBuilder(targetParameters[position.Value].ParameterType, argTypes[position.Value], sourceModID, targetModID); + argTypes[position.Value] = proxy.ReturnType; + parameterProxyTypeNames[position.Value] = builder.ProxyType.FullName; + } + } + + methodBuilder.SetReturnType(returnType); + methodBuilder.SetParameters(argTypes); + } + // create method body { ILGenerator il = methodBuilder.GetILGenerator(); - // load target instance - il.Emit(OpCodes.Ldarg_0); - il.Emit(OpCodes.Ldfld, instanceField); + void EmitCallInstance() + { + // load target instance + il.Emit(OpCodes.Ldarg_0); + il.Emit(OpCodes.Ldfld, instanceField); + + // invoke target method on instance + for (int i = 0; i < argTypes.Length; i++) + il.Emit(OpCodes.Ldarg, i + 1); + il.Emit(OpCodes.Callvirt, target); + } - // invoke target method on instance - for (int i = 0; i < argTypes.Length; i++) - il.Emit(OpCodes.Ldarg, i + 1); - il.Emit(OpCodes.Call, target); + if (returnValueProxyTypeName == null) + { + EmitCallInstance(); + } + else + { + // this.Glue.CreateInstanceForProxyTypeName(proxyTypeName, this.Instance.Call(args)) + il.Emit(OpCodes.Ldarg_0); + il.Emit(OpCodes.Ldfld, glueField); + il.Emit(OpCodes.Ldstr, returnValueProxyTypeName); + EmitCallInstance(); + il.Emit(OpCodes.Call, CreateInstanceForProxyTypeNameMethod); + } // return result il.Emit(OpCodes.Ret); @@ -175,5 +278,11 @@ namespace StardewModdingAPI.Framework.Reflection { ReturnType, Parameter } + + /// The result of matching a target and a proxy type. + private enum MatchingTypesResult + { + False, IfProxied, True + } } } diff --git a/src/SMAPI/Framework/Reflection/InterfaceProxyFactory.cs b/src/SMAPI/Framework/Reflection/InterfaceProxyFactory.cs index 5acba569..8ce187bf 100644 --- a/src/SMAPI/Framework/Reflection/InterfaceProxyFactory.cs +++ b/src/SMAPI/Framework/Reflection/InterfaceProxyFactory.cs @@ -35,26 +35,40 @@ namespace StardewModdingAPI.Framework.Reflection /// The unique ID of the mod providing the API. public TInterface CreateProxy(object instance, string sourceModID, string targetModID) where TInterface : class + { + // validate + if (instance == null) + throw new InvalidOperationException("Can't proxy access to a null API."); + + // create instance + InterfaceProxyBuilder builder = this.ObtainBuilder(instance.GetType(), typeof(TInterface), sourceModID, targetModID); + return (TInterface)builder.CreateInstance(instance, this); + } + + internal InterfaceProxyBuilder ObtainBuilder(Type targetType, Type interfaceType, string sourceModID, string targetModID) { lock (this.Builders) { // validate - if (instance == null) - throw new InvalidOperationException("Can't proxy access to a null API."); - if (!typeof(TInterface).IsInterface) + if (!interfaceType.IsInterface) throw new InvalidOperationException("The proxy type must be an interface, not a class."); // get proxy type - Type targetType = instance.GetType(); - string proxyTypeName = $"StardewModdingAPI.Proxies.From<{sourceModID}_{typeof(TInterface).FullName}>_To<{targetModID}_{targetType.FullName}>"; + string proxyTypeName = $"StardewModdingAPI.Proxies.From<{sourceModID}_{interfaceType.FullName}>_To<{targetModID}_{targetType.FullName}>"; if (!this.Builders.TryGetValue(proxyTypeName, out InterfaceProxyBuilder builder)) { - builder = new InterfaceProxyBuilder(proxyTypeName, this.ModuleBuilder, typeof(TInterface), targetType); + builder = new InterfaceProxyBuilder(this, proxyTypeName, this.ModuleBuilder, interfaceType, targetType, sourceModID, targetModID); this.Builders[proxyTypeName] = builder; } + return builder; + } + } - // create instance - return (TInterface)builder.CreateInstance(instance); + internal InterfaceProxyBuilder GetBuilderByProxyTypeName(string proxyTypeName) + { + lock (this.Builders) + { + return this.Builders.TryGetValue(proxyTypeName, out InterfaceProxyBuilder builder) ? builder : null; } } } diff --git a/src/SMAPI/Framework/Reflection/InterfaceProxyGlue.cs b/src/SMAPI/Framework/Reflection/InterfaceProxyGlue.cs new file mode 100644 index 00000000..4e027252 --- /dev/null +++ b/src/SMAPI/Framework/Reflection/InterfaceProxyGlue.cs @@ -0,0 +1,18 @@ +namespace StardewModdingAPI.Framework.Reflection +{ + public sealed class InterfaceProxyGlue + { + private readonly InterfaceProxyFactory Factory; + + internal InterfaceProxyGlue(InterfaceProxyFactory factory) + { + this.Factory = factory; + } + + public object CreateInstanceForProxyTypeName(string proxyTypeName, object toProxy) + { + var builder = this.Factory.GetBuilderByProxyTypeName(proxyTypeName); + return builder.CreateInstance(toProxy, this.Factory); + } + } +} -- cgit