public static IFileSystem CreateNewVolume([NotNull] string fileName, ulong volumeSize, [NotNull] IFileSystem destination)
{
Validate.ArgumentNotNull(fileName, "fileName");
Validate.ArgumentNotNull(destination, "destination");
var file = destination.CreateFile(fileName);
file.SetFileSize(volumeSize); // preliminary allocation. mounting system will increase this size slightly.
if (destination is PhysicalFileSystem)
{
var stream = new VirtualStream(file);
var diskAccess = new DirectDiskAccess(stream);
var vfs = new VirtualFileSystem(diskAccess, volumeSize);
file.SetFileSize(vfs.RealVolumeSize);
return vfs;
}
else
{
// for virtual files mounting file system directly.
// this allows parallel access from any thread, not restricted by writer lock in creating thread.
var destVfs = (VirtualFileSystem)destination;
file.Close();
var diskAccess = destVfs.MountDisk(fileName);
var vfs = new VirtualFileSystem(diskAccess, volumeSize);
diskAccess.SetFileSize(vfs.RealVolumeSize);
return vfs;
}
}
public static IFileSystem MountVirtual([NotNull] string fileName, [NotNull] IFileSystem source)
{
Validate.ArgumentNotNull(fileName, "fileName");
Validate.ArgumentNotNull(source, "source");
if (source is PhysicalFileSystem)
{
var file = source.OpenFile(fileName, true);
var stream = new VirtualStream(file);
var diskAccess = new DirectDiskAccess(stream);
return new VirtualFileSystem(diskAccess);
}
var vfs = (VirtualFileSystem)source;
var access = vfs.MountDisk(fileName);
return new VirtualFileSystem(access);
}