Safe stream update of file

Question

We perform updates of large text files by writing new records to a temp file, then replacing the old file with the temp file. A heavily abbreviated version:

Answer 1

Transactional NTFS on Windows Vista or later might be useful for your scenario.

Answer 2

I found it useful to wrap this pattern in it's own class.

class Program {
    static void Main( string[] args ) {
        using( var ft = new FileTransaction( @"C:\MyDir\MyFile.txt" ) )
        using( var sw = new StreamWriter( ft.TempPath ) ) {
            sw.WriteLine( "Hello" );
            ft.Commit();
        }
    }
}

public class FileTransaction :IDisposable {
    public string TempPath { get; private set; }
    private readonly string filePath;

    public FileTransaction( string filePath ) {
        this.filePath = filePath;
        this.TempPath = Path.GetTempFileName();
    }

    public void Dispose() {
        if( TempPath != null ) {
            try {
                File.Delete( TempPath );
            }
            catch { }
        }
    }

    public void Commit() {
        try {
            var oldPath = filePath + ".old";
            File.Move( filePath, oldPath );
        }
        catch {}

        File.Move( TempPath, filePath );

        TempPath = null;
    }
}