genode/ports/src/noux/terminal_file_system.h

/*
 * \brief  Terminal file system
 * \author Christian Prochaska
 * \date   2012-05-23
 */

/*
 * Copyright (C) 2012-2013 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 _NOUX__TERMINAL_FILE_SYSTEM_H_
#define _NOUX__TERMINAL_FILE_SYSTEM_H_

/* Genode includes */
#include <base/printf.h>
#include <base/lock.h>
#include <terminal_session/connection.h>
#include <util/string.h>

/* Noux includes */
#include <noux_session/sysio.h>
#include "file_system.h"


namespace Noux {

	class Terminal_file_system : public File_system
	{
		private:

			Terminal::Session_client _terminal;

			enum { FILENAME_MAX_LEN = 64 };
			char _filename[FILENAME_MAX_LEN];

			bool _is_root(const char *path)
			{
				return (strcmp(path, "") == 0) || (strcmp(path, "/") == 0);
			}

			bool _is_terminal_file(const char *path)
			{
				return (strlen(path) == (strlen(_filename) + 1)) &&
				       (strcmp(&path[1], _filename) == 0);
			}

		public:

			Terminal_file_system(Xml_node config)
			: _terminal(env()->parent()->session<Terminal::Session>
			             ("ram_quota=8192, label=\"noux(terminal_fs)\""))
			{
				_filename[0] = 0;
				try { config.attribute("name").value(_filename, sizeof(_filename)); }
				catch (...) { }

				/*
				 * Wait for connection-established signal
				 */

				/* create signal receiver, just for the single signal */
				Signal_context            sig_ctx;
				Signal_receiver           sig_rec;
				Signal_context_capability sig_cap = sig_rec.manage(&sig_ctx);

				/* register signal handler */
				_terminal.connected_sigh(sig_cap);

				/* wati for signal */
				sig_rec.wait_for_signal();
				sig_rec.dissolve(&sig_ctx);
			}


			/*********************************
			 ** Directory-service interface **
			 *********************************/

			Dataspace_capability dataspace(char const *path)
			{
				/* not supported */
				return Dataspace_capability();
			}

			void release(char const *path, Dataspace_capability ds_cap)
			{
				/* not supported */
			}

			bool stat(Sysio *sysio, char const *path)
			{
				Sysio::Stat st = { 0, 0, 0, 0, 0, 0 };

				if (_is_root(path))
					st.mode = Sysio::STAT_MODE_DIRECTORY;
				else if (_is_terminal_file(path)) {
					st.mode = Sysio::STAT_MODE_CHARDEV;
				} else {
					sysio->error.stat = Sysio::STAT_ERR_NO_ENTRY;
					return false;
				}

				sysio->stat_out.st = st;
				return true;
			}

			bool dirent(Sysio *sysio, char const *path, off_t index)
			{
				if (_is_root(path)) {
					if (index == 0) {
						sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_CHARDEV;
						strncpy(sysio->dirent_out.entry.name,
						        _filename,
						        sizeof(sysio->dirent_out.entry.name));
					} else {
						sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_END;
					}

					return true;
				}

				return false;
			}

			size_t num_dirent(char const *path)
			{
				if (_is_root(path))
					return 1;
				else
					return 0;
			}

			bool is_directory(char const *path)
			{
				if (_is_root(path))
					return true;

				return false;
			}

			char const *leaf_path(char const *path)
			{
				return path;
			}

			Vfs_handle *open(Sysio *sysio, char const *path)
			{
				if (!_is_terminal_file(path)) {
					sysio->error.open = Sysio::OPEN_ERR_UNACCESSIBLE;
					return 0;
				}

				return new (env()->heap()) Vfs_handle(this, this, 0);
			}

			bool unlink(Sysio *sysio, char const *path)
			{
				/* not supported */
				return false;
			}

			bool readlink(Sysio *sysio, char const *path)
			{
				/* not supported */
				return false;
			}

			bool rename(Sysio *sysio, char const *from_path, char const *to_path)
			{
				/* not supported */
				return false;
			}

			bool mkdir(Sysio *sysio, char const *path)
			{
				/* not supported */
				return false;
			}

			bool symlink(Sysio *sysio, char const *path)
			{
				/* not supported */
				return false;
			}

			/***************************
			 ** File_system interface **
			 ***************************/

			static char const *name() { return "terminal"; }


			/********************************
			 ** File I/O service interface **
			 ********************************/

			bool write(Sysio *sysio, Vfs_handle *handle)
			{
				sysio->write_out.count = _terminal.write(sysio->write_in.chunk, sysio->write_in.count);
				return true;
			}

			bool read(Sysio *sysio, Vfs_handle *vfs_handle)
			{
				sysio->read_out.count = _terminal.read(sysio->read_out.chunk, sysio->read_in.count);
				return true;
			}

			bool ftruncate(Sysio *sysio, Vfs_handle *vfs_handle) { return true; }

			bool check_unblock(Vfs_handle *vfs_handle, bool rd, bool wr, bool ex)
			{
				if (rd && (_terminal.avail() > 0))
					return true;

				if (wr)
					return true;

				return false;
			}

			void register_read_ready_sigh(Vfs_handle *vfs_handle,
			                              Signal_context_capability sigh)
			{
				_terminal.read_avail_sigh(sigh);
			}
	};
}

#endif /* _NOUX__TERMINAL_FILE_SYSTEM_H_ */