genode/repos/os/include/vfs/null_file_system.h

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/*
* \brief null filesystem
* \author Josef Soentgen
* \author Norman Feske
* \date 2012-07-31
*/
/*
* Copyright (C) 2012-2014 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__VFS__NULL_FILE_SYSTEM_H_
#define _INCLUDE__VFS__NULL_FILE_SYSTEM_H_
#include <vfs/single_file_system.h>
namespace Vfs { class Null_file_system; }
struct Vfs::Null_file_system : Single_file_system
{
Null_file_system(Xml_node config)
:
Single_file_system(NODE_TYPE_CHAR_DEVICE, name(), config)
{ }
static char const *name() { return "null"; }
/********************************
** File I/O service interface **
********************************/
Write_result write(Vfs_handle *handle, char const *, file_size count,
file_size &out_count) override
{
out_count = count;
return WRITE_OK;
}
Read_result read(Vfs_handle *vfs_handle, char *, file_size,
file_size &out_count) override
{
out_count = 0;
return READ_OK;
}
Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size) override
{
return FTRUNCATE_OK;
}
};
#endif /* _INCLUDE__VFS__NULL_FILE_SYSTEM_H_ */