Question

I am writing a blog where I upload text documents to a directory that contain HTML. Using the code below, do you anticipate I will have any issues with file locking or other problems I am not seeing? I am most concerned about the File.ReadAllText().

The directory will contain a list of files ex:

20120101_2300.txt

20120201_0100.txt

etc…

public class Website
{
    private string directory = "C:\\Web";
    public List<BlogEntry> GetArchives()
    {
        return GetArchives("");
    }

    public List<BlogEntry> GetArchives(string date)
    {
        var files = !string.IsNullOrEmpty(date) ? Directory.GetFiles(directory, "*.txt").Where(t => t.Contains(date)) : Directory.GetFiles("C:\\Web", "*.txt");
        var sb = files.Select(file => new BlogEntry {FullPath = file}).ToList();
        return sb.OrderByDescending(t => t.FileDate).Skip(5).ToList();
    }

    public List<BlogEntry> GetRecent()
    {
        var files = Directory.GetFiles(directory, "*.txt");
        var sb = files.Select(file => new BlogEntry {FullPath = file}).ToList();
        return sb.OrderByDescending(t => t.FileDate).Take(5).ToList();
    }
}

public class BlogEntry
{
    public string FullPath { get; set; }

    public DateTime FileDate
    {
        get { return DateTime.ParseExact(Path.GetFileNameWithoutExtension(FullPath), "yyyyMMdd_HHmm", CultureInfo.InvariantCulture); }
    }

    public string FileContents
    {
        get { return File.ReadAllText(FullPath); }
    }
}

Answer 1

As long as you’re sure there’s only one writer to a file (ie: yourself), this can work. More than that, and you’re likely to get into trouble. If you’re okay with this restriction, though, all you need to do is make sure to use a FileStream with the appropriate FileShare enumeration. It’s pretty easy if you wrap it in a StreamReader.

Write the property like this:

public string FileContents
{
    get { 
       using (var fs = new FileStream(FullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
       using (var rdr = new StreamReader(fs))
       {
          return rdr.ReadToEnd();
       }

    }
}

For performance, if your server has the ram, you’ll like do much better if you load these into a dictionary in memory the first time each record is asked for. Your code would look in the dictionary first and only read the file if the dictionary doesn’t have it.