Writes

gistfile1.txt

namespace Writing
{
    using System;
    using System.Diagnostics;
    using System.IO;
    using System.Threading;

    class Program
    {
        static void Main(string[] args)
        {
            for (int i = 0; i < 3; i++)
            {
                AsyncWrites();
                AsyncWritesQueued();
                SyncWrites();
            }
        }

        static void AsyncWrites()
        {
            Action write = null;
            var sw = new Stopwatch();
            sw.Start();

            var mre = new ManualResetEvent(false);
            long bytesWritten = 0;
            long bytesToWrite = 100*1024*1024;
            var data = new byte[16*1024*1024];
            var fs = new FileStream("foo", FileMode.Create, FileAccess.Write, FileShare.None, data.Length,
                                    FileOptions.Asynchronous | FileOptions.WriteThrough);
            write = () => fs.BeginWrite(data, 0, data.Length,
                                        ar =>
                                            {
                                                fs.EndWrite(ar);
                                                bytesWritten += data.Length;
                                                if (bytesWritten < bytesToWrite)
                                                {
                                                    write();
                                                }
                                                else
                                                {
                                                    fs.Flush();
                                                    fs.Close();
                                                    sw.Stop();
                                                    mre.Set();
                                                }
                                            }, null);

            write();
            mre.WaitOne();

            Console.WriteLine(sw.ElapsedMilliseconds);
        }


        static void AsyncWritesQueued()
        {
            Action write = null;
            var sw = new Stopwatch();
            sw.Start();

            var mre = new ManualResetEvent(false);
            long bytesWritten = 0;
            long bytesToWrite = 100*1024*1024;
            var data = new byte[16*1024*1024];
            var fs = new FileStream("foo3", FileMode.Create, FileAccess.Write, FileShare.None, data.Length,
                                    FileOptions.Asynchronous | FileOptions.WriteThrough);
            write = () => fs.BeginWrite(data, 0, data.Length,
                                        ar =>
                                            {
                                                fs.EndWrite(ar);
                                                bytesWritten += data.Length;
                                                if (bytesWritten >= bytesToWrite)
                                                {
                                                    fs.Flush();
                                                    fs.Close();
                                                    sw.Stop();
                                                    mre.Set();
                                                }
                                            }, null);

            for (int i = 0; i < bytesToWrite; i += data.Length)
            {
                write();
            }
            mre.WaitOne();

            Console.WriteLine(sw.ElapsedMilliseconds);
        }

        static void SyncWrites()
        {
            var sw = new Stopwatch();
            sw.Start();

            long bytesWritten = 0;
            long bytesToWrite = 100*1024*1024;
            var data = new byte[16*1024*1024];
            var fs = new FileStream("foo2", FileMode.Create, FileAccess.Write, FileShare.None, data.Length,
                                    FileOptions.WriteThrough);

            do
            {
                fs.Write(data, 0, data.Length);
                bytesWritten += data.Length;
            } while (bytesWritten < bytesToWrite);
            fs.Flush();
            fs.Close();
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);
        }
    }
}