public static void DoBenchmark()
{
const int Iterations = 10000000;
// Measure the time it takes to instantiate ten versions of
// IReadOnlyList<T>. GoInterface is not able to create generic wrappers,
// so every time you wrap the same generic type with a different type
// parameter, GoInterface produces a completely separate wrapper. This
// is not good for performance, but at least it makes it easy for our
// benchmark to pick 10 "different" classes to create wrappers of.
//
// It is possible to wrap List<byte> not only as IReadOnlyList<byte>
// but also as any larger integer type, such as IReadOnlyList<int>.
// However, the wrapping of the GetEnumerator() methods doesn't work.
// List<byte>.GetEnumerator() returns IEnumerator<byte>, but
// IReadOnlyList<int>.GetEnumerator() returns IEnumerator<int>. There is
// no implicit conversion from IEnumerator<byte> to IEnumerator<int>,
// so GoInterface fails to wrap it. However, by using ForceFrom we get
// around this limitation, which still allows us to use the indexer and
// Count properties. If you call GetEnumerator(), though, you get a
// MissingMethodException.
//
// Note that if you run this part of the benchmark twice without
// exiting the program, the second time around it should take zero
// milliseconds. And the benchmark generally runs more slowly right
// after you reboot your computer.
SimpleTimer timer = new SimpleTimer();
var dummy0 = GoInterface <IListSource <byte> > .ForceFrom(new List <byte>());
int firstOne = timer.Millisec;
var dummy1 = GoInterface <IListSource <short> > .ForceFrom(new List <byte>());
var dummy2 = GoInterface <IListSource <ushort> > .ForceFrom(new List <byte>());
var dummy3 = GoInterface <IListSource <int> > .ForceFrom(new List <byte>());
var dummy4 = GoInterface <IListSource <uint> > .ForceFrom(new List <byte>());
var dummy5 = GoInterface <IListSource <long> > .ForceFrom(new List <byte>());
var dummy6 = GoInterface <IListSource <ulong> > .ForceFrom(new List <byte>());
var dummy7 = GoInterface <IListSource <float> > .ForceFrom(new List <byte>());
var dummy8 = GoInterface <IListSource <double> > .ForceFrom(new List <byte>());
var dummy9 = GoInterface <IListSource <object> > .ForceFrom(new List <byte>());
int firstTen = timer.Millisec;
Console.WriteLine("First ten interfaces were wrapped in {0}ms ({1}ms for the first)", firstTen, firstOne);
// Second test: measure how long it takes to wrap the same List<int>
// many times, using either GoInterface class.
var list = new List <int>();
list.Add(0);
list.Add(1);
list.Add(2);
list.Add(3);
IList <int> ilist;
IListSource <int> rolist;
GoInterface <IListSource <int> > .From(list); // ignore first call
timer.Restart();
int i = 0;
do
{
ilist = list; // normal interface assignment is pretty much a no-op
} while (++i < Iterations);
int wrapTest0 = timer.Restart();
i = 0;
do
{
rolist = GoInterface <IListSource <int> > .From(list);
} while (++i < Iterations);
int wrapTest1 = timer.Restart();
i = 0;
do
{
rolist = GoInterface <IListSource <int>, List <int> > .From(list);
} while (++i < Iterations);
int wrapTest2 = timer.Restart();
Console.WriteLine("Wrapper creation speed ({0} times):", Iterations);
Console.WriteLine("- {0} ms for normal .NET interfaces (no-op)", wrapTest0);
Console.WriteLine("- {0} ms for GoInterface<IReadOnlyList<int>>.From()", wrapTest1);
Console.WriteLine("- {0} ms for GoInterface<IReadOnlyList<int>,List<int>>.From()", wrapTest2);
int total0 = 0, total1 = 0, total2 = 0;
timer.Restart();
for (i = 0; i < Iterations; i++)
{
total0 += list[i & 3];
}
int callTestDirectCall = timer.Restart();
for (i = 0; i < Iterations; i++)
{
total1 += ilist[i & 3];
}
int callTestNormalInterface = timer.Restart();
for (i = 0; i < Iterations; i++)
{
total2 += rolist[i & 3];
}
int callTestGoInterface = timer.Restart();
Debug.Assert(total0 == total1 && total1 == total2);
Console.WriteLine("Indexer call speed ({0} times):", Iterations);
Console.WriteLine("- {0} ms for direct calls (not through an interface)", callTestDirectCall);
Console.WriteLine("- {0} ms through IList<int>", callTestNormalInterface);
Console.WriteLine("- {0} ms through IReadOnlyList<int>", callTestGoInterface);
}
internal static global::System.Runtime.InteropServices.HandleRef getCPtr(GoInterface obj)
{
return((obj == null) ? new global::System.Runtime.InteropServices.HandleRef(null, global::System.IntPtr.Zero) : obj.swigCPtr);
}
public static ReverseView <T> From(IList <T> list)
{
return(GoInterface <ReverseView <T>, IList <T> > .From(list));
}
