public DynamicPropertyAccessor(PropertyInfo propertyInfo)
{
// target: (object)((({TargetType})instance).{Property})
// preparing parameter, object type
ParameterExpression instance = Expression.Parameter(
typeof(object), "instance");
// ({TargetType})instance
Expression instanceCast = Expression.Convert(
instance, propertyInfo.ReflectedType);
// (({TargetType})instance).{Property}
Expression propertyAccess = Expression.Property(
instanceCast, propertyInfo);
// (object)((({TargetType})instance).{Property})
UnaryExpression castPropertyValue = Expression.Convert(
propertyAccess, typeof(object));
// Lambda expression
Expression<Func<object, object>> lambda =
Expression.Lambda<Func<object, object>>(
castPropertyValue, instance);
this.m_getter = lambda.Compile();
MethodInfo setMethod = propertyInfo.GetSetMethod();
if (setMethod != null) {
this.m_dynamicSetter = new DynamicMethodExecutor(setMethod);
}
}
private void Watch()
{
int times = 1000000;
Program program = new Program();
object[] parameters = new object[] { new object(), new object(), new object() };
program.Call(null, null, null); // force JIT-compile
MethodInfo methodInfo = typeof(Program).GetMethod("Call");
Stopwatch watch1 = new Stopwatch();
watch1.Start();
for (int i = 0; i < times; i++) {
program.Call(parameters[0], parameters[1], parameters[2]);
}
watch1.Stop();
Console.WriteLine(watch1.Elapsed + " (Directly invoke)");
Stopwatch watch2 = new Stopwatch();
watch2.Start();
for (int i = 0; i < times; i++) {
methodInfo.Invoke(program, parameters);
}
watch2.Stop();
Console.WriteLine(watch2.Elapsed + " (Reflection invoke)");
DynamicMethodExecutor executor = new DynamicMethodExecutor(methodInfo);
Stopwatch watch3 = new Stopwatch();
watch3.Start();
for (int i = 0; i < times; i++) {
executor.Execute(program, parameters);
}
watch3.Stop();
Console.WriteLine(watch3.Elapsed + " (Dynamic executor)");
}