using System;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

namespace BlittableStructure {
	static class Program {
		delegate uint SizeOfType(Type type);
		static SizeOfType SizeOf = typeof(Marshal).GetMethod("SizeOfType", BindingFlags.NonPublic | BindingFlags.Static).CreateDelegate(typeof(SizeOfType)) as SizeOfType;

		static class Blittable<T> where T : struct {
			public static readonly int Size = (int)SizeOf(typeof(T));
			public static readonly unsafe void* Handle = typeof(T).TypeHandle.Value.ToPointer();
		}

		[FixedAddressValueType]
		static readonly unsafe void* handle  = typeof(Array).TypeHandle.Value.ToPointer(),
			type = typeof(byte[]).TypeHandle.Value.ToPointer();

		[MethodImpl(MethodImplOptions.AggressiveInlining, MethodCodeType = MethodCodeType.IL)]
		static unsafe T Read<T>(this Stream input) where T : struct {
			var size = Blittable<T>.Size;
			var tref = stackalloc byte[IntPtr.Size * 5 + size];
			var inst = (void**)tref + 3;
			inst[1] = (void*)size;
			inst[0] = handle;
			inst[-2] = type;
			inst[-3] = &inst;
			if(input.Read( __refvalue(*(TypedReference*)tref, byte[]), 0, size) < size) throw new EndOfStreamException();
			inst[-3] = inst + 2;
			inst[-2] = Blittable<T>.Handle;
			return __refvalue( *(TypedReference*)tref,T);
		}
		/// <summary>
		/// アプリケーションのメイン エントリ ポイントです。
		/// </summary>
		[STAThread]
		static unsafe void Main(string[] args) {
			Application.EnableVisualStyles();
			Application.SetCompatibleTextRenderingDefault(false);
			//Application.Run(new Form1());
			try {
				var i = 100000;
				var stack = stackalloc int[i];
				stack[1] = 1;
				stack[2] = 2;
				stack[3] = 3;
				stack[4] = 4;
				using(var mem = new UnmanagedMemoryStream((byte*)stack, sizeof(int) * i))
				using(var bin = new BinaryReader(mem, Encoding.ASCII, true)) {
					var sw = Stopwatch.StartNew();
					mem.Read<int>();
					Console.WriteLine(mem.Read<Rectangle>());

					mem.Seek(0L, SeekOrigin.Begin);
					sw.Restart();
					while(--i >= 0) mem.Read<int>();
					Console.WriteLine(sw.ElapsedTicks);

					i = 100000;

					mem.Seek(0L, SeekOrigin.Begin);
					sw.Restart();
					while(--i >= 0) bin.ReadInt32();
					Console.WriteLine(sw.ElapsedTicks);
				}
			} catch(Exception e) {
				Console.WriteLine(e);
			}
		}
	}
}