/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chfiles.h
* @brief Data files.
* @details This header defines abstract interfaces useful to access generic
* data files in a standardized way.
*
* @addtogroup data_files
* @details This module define an abstract interface for generic data files by
* extending the @p BaseSequentialStream interface. Note that no code
* is present, data files are just abstract interface-like structures,
* you should look at the systems as to a set of abstract C++ classes
* (even if written in C). This system has the advantage to make the
* access to streams independent from the implementation logic.<br>
* The data files interface can be used as base class for high level
* object types such as an API for a File System implementation.
* @{
*/
#ifndef _CHFILES_H_
#define _CHFILES_H_
/**
* @brief No error return code.
*/
#define FILE_OK 0
/**
* @brief Error code from the file stream methods.
*/
#define FILE_ERROR 0xFFFFFFFFUL
/**
* @brief File offset type.
*/
typedef uint32_t fileoffset_t;
/**
* @brief BaseFileStream specific methods.
*/
#define _base_file_stream_methods \
_base_sequential_stream_methods \
/* File close method.*/ \
uint32_t (*close)(void *instance); \
/* Get last error code method.*/ \
int (*geterror)(void *instance); \
/* File get size method.*/ \
fileoffset_t (*getsize)(void *instance); \
/* File get current position method.*/ \
fileoffset_t (*getposition)(void *instance); \
/* File seek method.*/ \
uint32_t (*lseek)(void *instance, fileoffset_t offset);
/**
* @brief @p BaseFileStream specific data.
* @note It is empty because @p BaseFileStream is only an interface
* without implementation.
*/
#define _base_file_stream_data \
_base_sequential_stream_data
/**
* @extends BaseSequentialStreamVMT
*
* @brief @p BaseFileStream virtual methods table.
*/
struct BaseFileStreamVMT {
_base_file_stream_methods
};
/**
* @extends BaseSequentialStream
*
* @brief Base file stream class.
* @details This class represents a generic file data stream.
*/
typedef struct {
/** @brief Virtual Methods Table.*/
const struct BaseFileStreamVMT *vmt;
_base_file_stream_data
} BaseFileStream;
/**
* @name Macro Functions (BaseFileStream)
* @{
*/
/**
* @brief Base file Stream close.
* @details The function closes a file stream.
*
* @param[in] ip pointer to a @p BaseFileStream or derived class
* @return The operation status.
* @retval FILE_OK no error.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define chFileStreamClose(ip) ((ip)->vmt->close(ip))
/**
* @brief Returns an implementation dependent error code.
*
* @param[in] ip pointer to a @p BaseFileStream or derived class
* @return Implementation dependent error code.
*
* @api
*/
#define chFileStreamGetError(ip) ((ip)->vmt->geterror(ip))
/**
* @brief Returns the current file size.
*
* @param[in] ip pointer to a @p BaseFileStream or derived class
* @return The file size.
*
* @api
*/
#define chFileStreamGetSize(ip) ((ip)->vmt->getposition(ip))
/**
* @brief Returns the current file pointer position.
*
* @param[in] ip pointer to a @p BaseFileStream or derived class
* @return The current position inside the file.
*
* @api
*/
#define chFileStreamGetPosition(ip) ((ip)->vmt->getposition(ip))
/**
* @brief Moves the file current pointer to an absolute position.
*
* @param[in] ip pointer to a @p BaseFileStream or derived class
* @param[in] offset new absolute position
* @return The operation status.
* @retval FILE_OK no error.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define chFileStreamSeek(ip, offset) ((ip)->vmt->lseek(ip, offset))
/** @} */
#endif /* _CHFILES_H_ */
/** @} */