191 lines
3.7 KiB
C++
191 lines
3.7 KiB
C++
/*
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* \brief null filesystem
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* \author Josef Soentgen
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* \date 2012-07-31
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*/
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/*
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* Copyright (C) 2012-2013 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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#ifndef _NOUX__NULL_FILE_SYSTEM_H_
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#define _NOUX__NULL_FILE_SYSTEM_H_
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/* Genode includes */
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#include <base/printf.h>
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#include <util/string.h>
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/* Noux includes */
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#include <noux_session/sysio.h>
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#include "file_system.h"
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namespace Noux {
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class Null_file_system : public File_system
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{
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private:
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const char *_filename() { return "null"; }
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bool _is_root(const char *path)
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{
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return (strcmp(path, "") == 0) || (strcmp(path, "/") == 0);
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}
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bool _is_null_file(const char *path)
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{
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return (strlen(path) == (strlen(_filename()) + 1)) &&
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(strcmp(&path[1], _filename()) == 0);
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}
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public:
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Null_file_system(Xml_node) { }
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/*********************************
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** Directory-service interface **
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*********************************/
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Dataspace_capability dataspace(char const *path)
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{
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/* not supported */
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return Dataspace_capability();
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}
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void release(char const *path, Dataspace_capability ds_cap)
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{
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/* not supported */
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}
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bool stat(Sysio *sysio, char const *path)
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{
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Sysio::Stat st = { 0, 0, 0, 0, 0, 0 };
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if (_is_root(path))
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st.mode = Sysio::STAT_MODE_DIRECTORY;
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else if (_is_null_file(path)) {
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st.mode = Sysio::STAT_MODE_CHARDEV;
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} else {
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sysio->error.stat = Sysio::STAT_ERR_NO_ENTRY;
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return false;
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}
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sysio->stat_out.st = st;
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return true;
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}
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bool dirent(Sysio *sysio, char const *path, off_t index)
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{
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if (_is_root(path)) {
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if (index == 0) {
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sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_CHARDEV;
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strncpy(sysio->dirent_out.entry.name,
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_filename(),
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sizeof(sysio->dirent_out.entry.name));
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} else {
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sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_END;
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}
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return true;
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}
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return false;
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}
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size_t num_dirent(char const *path)
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{
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if (_is_root(path))
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return 1;
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else
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return 0;
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}
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bool is_directory(char const *path)
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{
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if (_is_root(path))
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return true;
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return false;
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}
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char const *leaf_path(char const *path)
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{
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return path;
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}
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Vfs_handle *open(Sysio *sysio, char const *path)
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{
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if (!_is_null_file(path)) {
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sysio->error.open = Sysio::OPEN_ERR_UNACCESSIBLE;
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return 0;
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}
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return new (env()->heap()) Vfs_handle(this, this, 0);
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}
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bool unlink(Sysio *sysio, char const *path)
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{
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/* not supported */
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return false;
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}
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bool readlink(Sysio *sysio, char const *path)
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{
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/* not supported */
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return false;
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}
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bool rename(Sysio *sysio, char const *from_path, char const *to_path)
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{
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/* not supported */
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return false;
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}
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bool mkdir(Sysio *sysio, char const *path)
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{
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/* not supported */
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return false;
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}
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bool symlink(Sysio *sysio, char const *path)
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{
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/* not supported */
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return false;
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}
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/***************************
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** File_system interface **
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***************************/
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static char const *name() { return "null"; }
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/********************************
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** File I/O service interface **
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********************************/
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bool write(Sysio *sysio, Vfs_handle *handle)
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{
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sysio->write_out.count = sysio->write_in.count;
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return true;
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}
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bool read(Sysio *sysio, Vfs_handle *vfs_handle)
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{
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sysio->read_out.count = 0;
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return true;
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}
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bool ftruncate(Sysio *sysio, Vfs_handle *vfs_handle) { return true; }
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};
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}
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#endif /* _NOUX__NULL_FILE_SYSTEM_H_ */
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