contiki/core/cfs/cfs.h

205 lines
7.1 KiB
C

/**
* \addtogroup sys
* @{
*/
/**
* \defgroup cfs The Contiki file system interface
*
* The Contiki file system interface (CFS) defines an abstract API for
* reading directories and for reading and writing files. The CFS API
* is intentionally simple. The CFS API is modeled after the POSIX
* file API, and slightly simplified.
*
* @{
*/
/**
* \file
* CFS header file.
* \author
* Adam Dunkels <adam@sics.se>
*
*/
/*
* Copyright (c) 2004, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* Author: Adam Dunkels <adam@sics.se>
*
* $Id: cfs.h,v 1.3 2006/08/26 23:54:38 oliverschmidt Exp $
*/
#ifndef __CFS_H__
#define __CFS_H__
#include "cfs/cfs-service.h"
/**
* Specify that cfs_open() should open a file for reading.
*
* This constant indicates to cfs_open() that a file should be opened
* for reading. CFS_WRITE should be used if the file is opened for
* writing, and CFS_READ + CFS_WRITE indicates that the file is opened
* for both reading and writing.
*
* \sa cfs_open()
*/
#define CFS_READ 0
/**
* Specify that cfs_open() should open a file for writing.
*
* This constant indicates to cfs_open() that a file should be opened
* for writing. CFS_READ should be used if the file is opened for
* reading, and CFS_READ + CFS_WRITE indicates that the file is opened
* for both reading and writing.
*
* \sa cfs_open()
*/
#define CFS_WRITE 1
/**
* \brief Open a file.
* \param name The name of the file.
* \param flags CFS_READ, or CFS_WRITE, or both.
* \return A file descriptor, if the file could be opened, or -1 if
* the file could not be opened.
*
* This function opens a file and returns a file
* descriptor for the opened file. If the file could not
* be opened, the function returns -1. The function can
* open a file for reading or writing, or both.
*
* An opened file must be closed with cfs_close().
*
* \sa CFS_READ
* \sa CFS_WRITE
* \sa cfs_close()
*/
int cfs_open(const char *name, int flags);
/**
* \brief Close an open file.
* \param fd The file descriptor of the open file.
*
* This function closes a file that has previously been
* opened with cfs_open().
*/
void cfs_close(int fd);
/**
* \brief Read data from an open file.
* \param fd The file descriptor of the open file.
* \param buf The buffer in which data should be read from the file.
* \param len The number of bytes that should be read.
* \return The number of bytes that was actually read from the file.
*
* This function reads data from an open file into a
* buffer. The file must have first been opened with
* cfs_open() and the CFS_READ flag.
*/
int cfs_read(int fd, char *buf, unsigned int len);
/**
* \brief Write data to an open file.
* \param fd The file descriptor of the open file.
* \param buf The buffer from which data should be written to the file.
* \param len The number of bytes that should be written.
* \return The number of bytes that was actually written to the file.
*
* This function reads writes data from a memory buffer to
* an open file. The file must have been opened with
* cfs_open() and the CFS_WRITE flag.
*/
int cfs_write(int fd, char *buf, unsigned int len);
/**
* \brief Seek to a specified position in an open file.
* \param fd The file descriptor of the open file.
* \param offset The position in the file.
* \return The new position in the file.
*
* This function moves the file position to the specified
* position in the file. The next byte that is read from
* or written to the file will be at the position given by
* the offset parameter.
*/
int cfs_seek(int fd, unsigned int offset);
/**
* \brief Open a directory for reading directory entries.
* \param dirp A pointer to a struct cfs_dir that is filled in by the function.
* \param name The name of the directory.
* \return 0 or -1 if the directory could not be opened.
*
* \sa cfs_readdir()
* \sa cfs_closedir()
*/
int cfs_opendir(struct cfs_dir *dirp, const char *name);
/**
* \brief Read a directory entry
* \param dirp A pointer to a struct cfs_dir that has been opened with cfs_opendir().
* \param dirent A pointer to a struct cfs_dirent that is filled in by cfs_readdir()
* \retval 0 If a directory entry was read.
* \retval 0 If no more directory entries can be read.
*
* \sa cfs_opendir()
* \sa cfs_closedir()
*/
int cfs_readdir(struct cfs_dir *dirp, struct cfs_dirent *dirent);
/**
* \brief Close a directory opened with cfs_opendir().
* \param dirp A pointer to a struct cfs_dir that has been opened with cfs_opendir().
*
* \sa cfs_opendir()
* \sa cfs_readdir()
*/
int cfs_closedir(struct cfs_dir *dirp);
CCIF const struct cfs_service_interface *cfs_find_service(void);
#define cfs_open(name, flags) (cfs_find_service()->open(name, flags))
#define cfs_close(fd) (cfs_find_service()->close(fd))
#define cfs_read(fd, buf, len) (cfs_find_service()->read(fd, buf, len))
#define cfs_write(fd, buf, len) (cfs_find_service()->write(fd, buf, len))
#define cfs_seek(fd, off) (cfs_find_service()->seek(fd, off))
#define cfs_opendir(dirp, name) (cfs_find_service()->opendir(dirp, name))
#define cfs_readdir(dirp, ent) (cfs_find_service()->readdir(dirp, ent))
#define cfs_closedir(dirp) (cfs_find_service()->closedir(dirp))
#endif /* __CFS_H__ */
/** @} */
/** @} */