csharp-sdk-upm/Libs/Newtonsoft.Json/Utilities/ExpressionReflectionDelegat...

383 lines
15 KiB
C#

#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion
#if !(NET20 || NET35)
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System;
using System.Linq.Expressions;
using System.Reflection;
using LC.Newtonsoft.Json.Serialization;
namespace LC.Newtonsoft.Json.Utilities
{
internal class ExpressionReflectionDelegateFactory : ReflectionDelegateFactory
{
private static readonly ExpressionReflectionDelegateFactory _instance = new ExpressionReflectionDelegateFactory();
internal static ReflectionDelegateFactory Instance => _instance;
public override ObjectConstructor<object> CreateParameterizedConstructor(MethodBase method)
{
ValidationUtils.ArgumentNotNull(method, nameof(method));
Type type = typeof(object);
ParameterExpression argsParameterExpression = Expression.Parameter(typeof(object[]), "args");
Expression callExpression = BuildMethodCall(method, type, null, argsParameterExpression);
LambdaExpression lambdaExpression = Expression.Lambda(typeof(ObjectConstructor<object>), callExpression, argsParameterExpression);
ObjectConstructor<object> compiled = (ObjectConstructor<object>)lambdaExpression.Compile();
return compiled;
}
public override MethodCall<T, object> CreateMethodCall<T>(MethodBase method)
{
ValidationUtils.ArgumentNotNull(method, nameof(method));
Type type = typeof(object);
ParameterExpression targetParameterExpression = Expression.Parameter(type, "target");
ParameterExpression argsParameterExpression = Expression.Parameter(typeof(object[]), "args");
Expression callExpression = BuildMethodCall(method, type, targetParameterExpression, argsParameterExpression);
LambdaExpression lambdaExpression = Expression.Lambda(typeof(MethodCall<T, object>), callExpression, targetParameterExpression, argsParameterExpression);
MethodCall<T, object> compiled = (MethodCall<T, object>)lambdaExpression.Compile();
return compiled;
}
private class ByRefParameter
{
public Expression Value;
public ParameterExpression Variable;
public bool IsOut;
}
private Expression BuildMethodCall(MethodBase method, Type type, ParameterExpression targetParameterExpression, ParameterExpression argsParameterExpression)
{
ParameterInfo[] parametersInfo = method.GetParameters();
Expression[] argsExpression;
IList<ByRefParameter> refParameterMap;
if (parametersInfo.Length == 0)
{
argsExpression = CollectionUtils.ArrayEmpty<Expression>();
refParameterMap = CollectionUtils.ArrayEmpty<ByRefParameter>();
}
else
{
argsExpression = new Expression[parametersInfo.Length];
refParameterMap = new List<ByRefParameter>();
for (int i = 0; i < parametersInfo.Length; i++)
{
ParameterInfo parameter = parametersInfo[i];
Type parameterType = parameter.ParameterType;
bool isByRef = false;
if (parameterType.IsByRef)
{
parameterType = parameterType.GetElementType();
isByRef = true;
}
Expression indexExpression = Expression.Constant(i);
Expression paramAccessorExpression = Expression.ArrayIndex(argsParameterExpression, indexExpression);
Expression argExpression = EnsureCastExpression(paramAccessorExpression, parameterType, !isByRef);
if (isByRef)
{
ParameterExpression variable = Expression.Variable(parameterType);
refParameterMap.Add(new ByRefParameter {Value = argExpression, Variable = variable, IsOut = parameter.IsOut});
argExpression = variable;
}
argsExpression[i] = argExpression;
}
}
Expression callExpression;
if (method.IsConstructor)
{
callExpression = Expression.New((ConstructorInfo)method, argsExpression);
}
else if (method.IsStatic)
{
callExpression = Expression.Call((MethodInfo)method, argsExpression);
}
else
{
Expression readParameter = EnsureCastExpression(targetParameterExpression, method.DeclaringType);
callExpression = Expression.Call(readParameter, (MethodInfo)method, argsExpression);
}
if (method is MethodInfo m)
{
if (m.ReturnType != typeof(void))
{
callExpression = EnsureCastExpression(callExpression, type);
}
else
{
callExpression = Expression.Block(callExpression, Expression.Constant(null));
}
}
else
{
callExpression = EnsureCastExpression(callExpression, type);
}
if (refParameterMap.Count > 0)
{
IList<ParameterExpression> variableExpressions = new List<ParameterExpression>();
IList<Expression> bodyExpressions = new List<Expression>();
foreach (ByRefParameter p in refParameterMap)
{
if (!p.IsOut)
{
bodyExpressions.Add(Expression.Assign(p.Variable, p.Value));
}
variableExpressions.Add(p.Variable);
}
bodyExpressions.Add(callExpression);
callExpression = Expression.Block(variableExpressions, bodyExpressions);
}
return callExpression;
}
public override Func<T> CreateDefaultConstructor<T>(Type type)
{
ValidationUtils.ArgumentNotNull(type, "type");
// avoid error from expressions compiler because of abstract class
if (type.IsAbstract())
{
return () => (T)Activator.CreateInstance(type);
}
try
{
Type resultType = typeof(T);
Expression expression = Expression.New(type);
expression = EnsureCastExpression(expression, resultType);
LambdaExpression lambdaExpression = Expression.Lambda(typeof(Func<T>), expression);
Func<T> compiled = (Func<T>)lambdaExpression.Compile();
return compiled;
}
catch
{
// an error can be thrown if constructor is not valid on Win8
// will have INVOCATION_FLAGS_NON_W8P_FX_API invocation flag
return () => (T)Activator.CreateInstance(type);
}
}
public override Func<T, object> CreateGet<T>(PropertyInfo propertyInfo)
{
ValidationUtils.ArgumentNotNull(propertyInfo, nameof(propertyInfo));
Type instanceType = typeof(T);
Type resultType = typeof(object);
ParameterExpression parameterExpression = Expression.Parameter(instanceType, "instance");
Expression resultExpression;
MethodInfo getMethod = propertyInfo.GetGetMethod(true);
if (getMethod.IsStatic)
{
resultExpression = Expression.MakeMemberAccess(null, propertyInfo);
}
else
{
Expression readParameter = EnsureCastExpression(parameterExpression, propertyInfo.DeclaringType);
resultExpression = Expression.MakeMemberAccess(readParameter, propertyInfo);
}
resultExpression = EnsureCastExpression(resultExpression, resultType);
LambdaExpression lambdaExpression = Expression.Lambda(typeof(Func<T, object>), resultExpression, parameterExpression);
Func<T, object> compiled = (Func<T, object>)lambdaExpression.Compile();
return compiled;
}
public override Func<T, object> CreateGet<T>(FieldInfo fieldInfo)
{
ValidationUtils.ArgumentNotNull(fieldInfo, nameof(fieldInfo));
ParameterExpression sourceParameter = Expression.Parameter(typeof(T), "source");
Expression fieldExpression;
if (fieldInfo.IsStatic)
{
fieldExpression = Expression.Field(null, fieldInfo);
}
else
{
Expression sourceExpression = EnsureCastExpression(sourceParameter, fieldInfo.DeclaringType);
fieldExpression = Expression.Field(sourceExpression, fieldInfo);
}
fieldExpression = EnsureCastExpression(fieldExpression, typeof(object));
Func<T, object> compiled = Expression.Lambda<Func<T, object>>(fieldExpression, sourceParameter).Compile();
return compiled;
}
public override Action<T, object> CreateSet<T>(FieldInfo fieldInfo)
{
ValidationUtils.ArgumentNotNull(fieldInfo, nameof(fieldInfo));
// use reflection for structs
// expression doesn't correctly set value
if (fieldInfo.DeclaringType.IsValueType() || fieldInfo.IsInitOnly)
{
return LateBoundReflectionDelegateFactory.Instance.CreateSet<T>(fieldInfo);
}
ParameterExpression sourceParameterExpression = Expression.Parameter(typeof(T), "source");
ParameterExpression valueParameterExpression = Expression.Parameter(typeof(object), "value");
Expression fieldExpression;
if (fieldInfo.IsStatic)
{
fieldExpression = Expression.Field(null, fieldInfo);
}
else
{
Expression sourceExpression = EnsureCastExpression(sourceParameterExpression, fieldInfo.DeclaringType);
fieldExpression = Expression.Field(sourceExpression, fieldInfo);
}
Expression valueExpression = EnsureCastExpression(valueParameterExpression, fieldExpression.Type);
BinaryExpression assignExpression = Expression.Assign(fieldExpression, valueExpression);
LambdaExpression lambdaExpression = Expression.Lambda(typeof(Action<T, object>), assignExpression, sourceParameterExpression, valueParameterExpression);
Action<T, object> compiled = (Action<T, object>)lambdaExpression.Compile();
return compiled;
}
public override Action<T, object> CreateSet<T>(PropertyInfo propertyInfo)
{
ValidationUtils.ArgumentNotNull(propertyInfo, nameof(propertyInfo));
// use reflection for structs
// expression doesn't correctly set value
if (propertyInfo.DeclaringType.IsValueType())
{
return LateBoundReflectionDelegateFactory.Instance.CreateSet<T>(propertyInfo);
}
Type instanceType = typeof(T);
Type valueType = typeof(object);
ParameterExpression instanceParameter = Expression.Parameter(instanceType, "instance");
ParameterExpression valueParameter = Expression.Parameter(valueType, "value");
Expression readValueParameter = EnsureCastExpression(valueParameter, propertyInfo.PropertyType);
MethodInfo setMethod = propertyInfo.GetSetMethod(true);
Expression setExpression;
if (setMethod.IsStatic)
{
setExpression = Expression.Call(setMethod, readValueParameter);
}
else
{
Expression readInstanceParameter = EnsureCastExpression(instanceParameter, propertyInfo.DeclaringType);
setExpression = Expression.Call(readInstanceParameter, setMethod, readValueParameter);
}
LambdaExpression lambdaExpression = Expression.Lambda(typeof(Action<T, object>), setExpression, instanceParameter, valueParameter);
Action<T, object> compiled = (Action<T, object>)lambdaExpression.Compile();
return compiled;
}
private Expression EnsureCastExpression(Expression expression, Type targetType, bool allowWidening = false)
{
Type expressionType = expression.Type;
// check if a cast or conversion is required
if (expressionType == targetType || (!expressionType.IsValueType() && targetType.IsAssignableFrom(expressionType)))
{
return expression;
}
if (targetType.IsValueType())
{
Expression convert = Expression.Unbox(expression, targetType);
if (allowWidening && targetType.IsPrimitive())
{
MethodInfo toTargetTypeMethod = typeof(Convert)
.GetMethod("To" + targetType.Name, new[] { typeof(object) });
if (toTargetTypeMethod != null)
{
convert = Expression.Condition(
Expression.TypeIs(expression, targetType),
convert,
Expression.Call(toTargetTypeMethod, expression));
}
}
return Expression.Condition(
Expression.Equal(expression, Expression.Constant(null, typeof(object))),
Expression.Default(targetType),
convert);
}
return Expression.Convert(expression, targetType);
}
}
}
#endif