public override long Seek(long offset, SeekOrigin origin)
{
if (!CanSeek)
{
throw new NotSupportedException("The stream does not support seeking");
}
if (IsAsync && origin == SeekOrigin.Current)
{
throw new NotSupportedException("Cannot tell what the offset is in async mode");
}
SeekPosition seekPos = SeekPosition.Start;
long newOffset = -1;
switch (origin)
{
case SeekOrigin.Begin:
seekPos = SeekPosition.Start;
newOffset = offset;
break;
case SeekOrigin.Current:
seekPos = SeekPosition.Current;
break;
case SeekOrigin.End:
seekPos = SeekPosition.End;
newOffset = Length + offset;
break;
}
Result result;
if (async)
{
Async.Seek(handle, seekPos, offset, callback);
Wait();
result = asyncResult;
}
else
{
result = Sync.Seek(handle, seekPos, offset);
}
Vfs.ThrowException(Uri, result);
return(newOffset);
}
public VfsStream(string text_uri, FileMode mode, bool async)
{
if (text_uri == null)
{
throw new ArgumentNullException("uri");
}
if (text_uri == "")
{
throw new ArgumentNullException("Uri is empty");
}
if (mode < FileMode.CreateNew || mode > FileMode.Append)
{
throw new ArgumentOutOfRangeException("mode");
}
if (text_uri.IndexOfAny(Path.InvalidPathChars) != -1)
{
throw new ArgumentException("Uri has invalid chars");
}
uri = new Gnome.Vfs.Uri(text_uri);
if (mode == FileMode.Open && !uri.Exists)
{
throw new FileNotFoundException("Could not find uri \"" + text_uri + "\".");
}
if (mode == FileMode.CreateNew)
{
string dname = uri.ExtractDirname();
if (dname != "" && !new Uri(dname).Exists)
{
throw new DirectoryNotFoundException("Could not find a part of " +
"the path \"" + dname + "\".");
}
}
if (async)
{
callback = new AsyncCallback(OnAsyncCallback);
readCallback = new AsyncReadCallback(OnAsyncReadCallback);
writeCallback = new AsyncWriteCallback(OnAsyncWriteCallback);
}
OpenMode om = OpenMode.None;
switch (mode)
{
case FileMode.CreateNew:
case FileMode.Create:
case FileMode.Truncate:
case FileMode.Append:
om = OpenMode.Write;
access = FileAccess.Write;
break;
case FileMode.OpenOrCreate:
if (uri.Exists)
{
om = OpenMode.Read;
access = FileAccess.Read;
}
else
{
om = OpenMode.Write;
access = FileAccess.Write;
}
break;
case FileMode.Open:
om = OpenMode.Read;
access = FileAccess.Read;
break;
}
/* 644 */
FilePermissions perms = FilePermissions.UserRead |
FilePermissions.UserWrite |
FilePermissions.GroupRead |
FilePermissions.OtherRead;
Result result;
handle = null;
switch (mode)
{
case FileMode.Append:
if (uri.Exists)
{
if (async)
{
handle = Async.Open(uri, om,
(int)Async.Priority.Default,
callback);
Wait();
Async.Seek(handle, SeekPosition.End, 0, callback);
Wait();
}
else
{
handle = Sync.Open(uri, om);
result = Sync.Seek(handle, SeekPosition.End, 0);
Vfs.ThrowException(uri, result);
}
}
else
{
if (async)
{
handle = Async.Create(uri, om, true, perms,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Create(uri, om, true, perms);
}
}
break;
case FileMode.Create:
if (uri.Exists)
{
if (async)
{
handle = Async.Open(uri, om,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Open(uri, om);
result = uri.Truncate(0);
Vfs.ThrowException(uri, result);
}
}
else
{
handle = Sync.Create(uri, om, true, perms);
}
break;
case FileMode.CreateNew:
if (uri.Exists)
{
throw new IOException("Uri \"" + text_uri + "\" already exists.");
}
else
{
if (async)
{
handle = Async.Create(uri, om, true, perms,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Create(uri, om, true, perms);
}
}
break;
case FileMode.Open:
if (uri.Exists)
{
if (async)
{
handle = Async.Open(uri, om,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Open(uri, om);
}
}
else
{
throw new FileNotFoundException(text_uri);
}
break;
case FileMode.OpenOrCreate:
if (uri.Exists)
{
if (async)
{
handle = Async.Open(uri, om,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Open(uri, om);
}
}
else
{
if (async)
{
handle = Async.Create(uri, om, true, perms,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Create(uri, om, true, perms);
}
}
break;
case FileMode.Truncate:
if (uri.Exists)
{
result = uri.Truncate(0);
if (async)
{
handle = Async.Open(uri, om,
(int)Async.Priority.Default,
callback);
Wait();
}
else
{
handle = Sync.Open(uri, om);
Vfs.ThrowException(uri, result);
}
}
else
{
throw new FileNotFoundException(text_uri);
}
break;
}
this.mode = mode;
this.canseek = true;
this.async = async;
}
