Emery Hemingway
82a683eccc
Reduce the size and forward compatibility of VFS file-system constructors by passing an object holding accessors for 'Genode::Env', 'Genode::Allocator', response handlers, and the root file-system. Fix #2742
89 lines
2.0 KiB
C++
89 lines
2.0 KiB
C++
/*
|
|
* \brief null filesystem
|
|
* \author Josef Soentgen
|
|
* \author Norman Feske
|
|
* \date 2012-07-31
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2012-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#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(Vfs::Env&, Genode::Xml_node config)
|
|
:
|
|
Single_file_system(NODE_TYPE_CHAR_DEVICE, name(), config)
|
|
{ }
|
|
|
|
static char const *name() { return "null"; }
|
|
char const *type() override { return "null"; }
|
|
|
|
struct Null_vfs_handle : Single_vfs_handle
|
|
{
|
|
Null_vfs_handle(Directory_service &ds,
|
|
File_io_service &fs,
|
|
Genode::Allocator &alloc)
|
|
: Single_vfs_handle(ds, fs, alloc, 0) { }
|
|
|
|
Read_result read(char *, file_size, file_size &out_count) override
|
|
{
|
|
out_count = 0;
|
|
|
|
return READ_OK;
|
|
}
|
|
|
|
Write_result write(char const *, file_size count,
|
|
file_size &out_count) override
|
|
{
|
|
out_count = count;
|
|
|
|
return WRITE_OK;
|
|
}
|
|
|
|
bool read_ready() { return false; }
|
|
};
|
|
|
|
/*********************************
|
|
** Directory service interface **
|
|
*********************************/
|
|
|
|
Open_result open(char const *path, unsigned,
|
|
Vfs_handle **out_handle,
|
|
Allocator &alloc) override
|
|
{
|
|
if (!_single_file(path))
|
|
return OPEN_ERR_UNACCESSIBLE;
|
|
|
|
try {
|
|
*out_handle = new (alloc)
|
|
Null_vfs_handle(*this, *this, alloc);
|
|
return OPEN_OK;
|
|
}
|
|
catch (Genode::Out_of_ram) { return OPEN_ERR_OUT_OF_RAM; }
|
|
catch (Genode::Out_of_caps) { return OPEN_ERR_OUT_OF_CAPS; }
|
|
}
|
|
|
|
/********************************
|
|
** File I/O service interface **
|
|
********************************/
|
|
|
|
Ftruncate_result ftruncate(Vfs_handle *, file_size) override
|
|
{
|
|
return FTRUNCATE_OK;
|
|
}
|
|
};
|
|
|
|
#endif /* _INCLUDE__VFS__NULL_FILE_SYSTEM_H_ */
|