[Mono-dev] Announce: Mono.Fuse 0.3.0

[pablosantosluac]

Hey, next step could be having the same on Windows? Do you imagine it? File 
system kernel modules written in C#????

ok, let's stop dreaming... :-P
----- Original Message ----- 
From: "Jonathan Pryor" <jonpryor at vt.edu>
To: "Mono List" <mono-list at ximian.com>; "mono-devel-list" 
<mono-devel-list at ximian.com>
Sent: Monday, September 11, 2006 12:04 PM
Subject: [Mono-dev] Announce: Mono.Fuse 0.3.0


> Mono.Fuse is a C# binding for the FUSE library.
>
> This release features a near complete change in the public FileSystem
> API; a complete API change list is available at:
>
> http://www.jprl.com/Blog/archive/development/mono/2006/Sep-11.html
>
> Hopefully this will be the last major API change, though I would
> appreciate any and all feedback on the current API.
>
> The most "interesting" change is for OnReadDirectory().  It was
> previously:
>
> protected virtual Errno
> OnReadDirectory(string path, out string[] paths,
> OpenedFileInfo info);
>
> It is now:
>
> protected virtual Errno
> OnReadDirectory(string path, OpenedPathInfo info,
> out IEnumerable<FileSystemEntry> paths);
>
> That is, `out string[]' is now `out IEnumerable<FileSystemEntry>'.  This
> allows for two things:
>
> 1.  A performance boost: an array containing the names of all file
> system entries in `path' doesn't need to be created all at once.  For
> large directories (hundreds-thousands of files), this can really slow
> things down.  The IEnumerable interface allows file system entries to be
> retrieved piecemeal.
>
> 2.  C# iterators can be used to implement directory reading.  From
> HelloFS.cs:
>
> private IEnumerable<FileSystemEntry> GetEntries ()
> {
>     yield return ".";
>     yield return "..";
>     yield return "hello";
>     yield return "data";
>     if (have_data_im)
>         yield return "data.im";
> }
>
> protected override Errno OnReadDirectory (string path,
>         OpenedPathInfo info,
>                out IEnumerable<FileSystemEntry> paths)
> {
>     paths = GetEntries ();
>     return 0;
> }
>
> I think (2) is particularly cool.
>
>
> Design Questions:
>
> OnReadDirectory() uses FileSystemEntry, which is:
>
> class FileSystemEntry
>     public string Path {get;}
>     public Stat Stat;
>     public FileSystemEntry (string path);
>     public static implicit operator FileSystemEntry (string);
> }
>
> This has a public field Stat, which is against normal design guidelines.
> This was done because Stat is a 96-byte structure, so these shouldn't be
> created on the stack that often, and a read/write Property would require
> much more stack use.  Is this reasonable?
>
> The Stat field is optional.  It is only used Stat.st_ino is non-zero (as
> FUSE 2.5.3 currently only reads the st_ino & st_mode fields, though I
> imagine this could be extended in the future).  Is this reasonable?  Or
> should an alternative mechanism be used to determine when the Stat
> instance should be used?
>
> Is it a good idea to have the implicit conversion from string to
> FileSystemEntry?
>
>
> Download:
>
> Mono.Fuse 0.3.0 is available for download at:
>
> http://www.jprl.com/Projects/mono-fuse/mono-fuse-0.3.0.tar.gz
>
> Thanks,
> - Jon
>
>
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