internal SparseStream OpenFile(FileName name, FileMode mode, FileAccess fileAccess)
{
if (mode == FileMode.Append || mode == FileMode.Truncate)
{
throw new NotImplementedException();
}
long fileId = FindEntry(name);
bool exists = fileId != -1;
if (mode == FileMode.CreateNew && exists)
{
throw new IOException("File already exists");
}
else if (mode == FileMode.Open && !exists)
{
throw new FileNotFoundException("File not found", name.GetDisplayName(_fileSystem.FatOptions.FileNameEncoding));
}
else if ((mode == FileMode.Open || mode == FileMode.OpenOrCreate || mode == FileMode.Create) && exists)
{
SparseStream stream = new FatFileStream(_fileSystem, this, fileId, fileAccess);
if (mode == FileMode.Create)
{
stream.SetLength(0);
}
HandleAccessed(false);
return stream;
}
else if ((mode == FileMode.OpenOrCreate || mode == FileMode.CreateNew || mode == FileMode.Create) && !exists)
{
// Create new file
DirectoryEntry newEntry = new DirectoryEntry(_fileSystem.FatOptions, name, FatAttributes.Archive);
newEntry.FirstCluster = 0; // i.e. Zero-length
newEntry.CreationTime = _fileSystem.ConvertFromUtc(DateTime.UtcNow);
newEntry.LastWriteTime = newEntry.CreationTime;
fileId = AddEntry(newEntry);
return new FatFileStream(_fileSystem, this, fileId, fileAccess);
}
else
{
// Should never get here...
throw new NotImplementedException();
}
}
