tinySA/os/hal/include/hal_files.h

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/*
ChibiOS/HAL - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012,2013,2014 Giovanni Di Sirio.
This file is part of ChibiOS/HAL
ChibiOS/HAL 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 hal_files.h
* @brief Data files.
* @details This header defines abstract interfaces useful to access generic
* data files in a standardized way.
*
* @addtogroup FILE_STREAMS
* @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 _HAL_FILES_H_
#define _HAL_FILES_H_
/**
* @name Files return codes
* @{
*/
/**
* @brief No error return code.
*/
#define FILE_OK (fileoffset_t)STM_OK
/**
* @brief Error code from the file stream methods.
*/
#define FILE_ERROR (fileoffset_t)STM_TIMEOUT
/**
* @brief End-of-file condition for file get/put methods.
*/
#define FILE_EOF (fileoffset_t)STM_RESET
/** @} */
/**
* @brief File offset type.
*/
typedef uint32_t fileoffset_t;
/**
* @brief FileStream specific methods.
*/
#define _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 FileStream specific data.
* @note It is empty because @p FileStream is only an interface
* without implementation.
*/
#define _file_stream_data \
_base_sequential_stream_data
/**
* @extends BaseSequentialStreamVMT
*
* @brief @p FileStream virtual methods table.
*/
struct FileStreamVMT {
_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 FileStreamVMT *vmt;
_file_stream_data
} FileStream;
/**
* @name Macro Functions (FileStream)
* @{
*/
/**
* @brief File stream write.
* @details The function writes data from a buffer to a file stream.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @param[in] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred
* @return The number of bytes transferred. The return value can
* be less than the specified number of bytes if an
* end-of-file condition has been met.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define fileStreamWrite(ip, bp, n) streamWrite(ip, bp, n)
/**
* @brief File stream read.
* @details The function reads data from a file stream into a buffer.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @param[out] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred
* @return The number of bytes transferred. The return value can
* be less than the specified number of bytes if an
* end-of-file condition has been met.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define fileStreamRead(ip, bp, n) streamRead(ip, bp, n)
/**
* @brief File stream blocking byte write.
* @details This function writes a byte value to a channel. If the channel
* is not ready to accept data then the calling thread is suspended.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @param[in] b the byte value to be written to the channel
*
* @return The operation status.
* @retval FILE_OK if the operation succeeded.
* @retval FILE_ERROR operation failed.
* @retval FILE_EOF if an end-of-file condition has been met.
*
* @api
*/
#define fileStreamPut(ip, b) streamPut(ip, b)
/**
* @brief File stream blocking byte read.
* @details This function reads a byte value from a channel. If the data
* is not available then the calling thread is suspended.
*
* @param[in] ip pointer to a @p FileStream or derived class
*
* @return A byte value from the queue.
* @retval FILE_ERROR operation failed.
* @retval FILE_EOF if an end-of-file condition has been met.
*
* @api
*/
#define fileStreamGet(ip) streamGet(ip)
/**
* @brief File Stream close.
* @details The function closes a file stream.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @return The operation status.
* @retval FILE_OK no error.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define fileStreamClose(ip) ((ip)->vmt->close(ip))
/**
* @brief Returns an implementation dependent error code.
* @pre The previously called function must have returned @p FILE_ERROR.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @return Implementation dependent error code.
*
* @api
*/
#define fileStreamGetError(ip) ((ip)->vmt->geterror(ip))
/**
* @brief Returns the current file size.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @return The file size.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define fileStreamGetSize(ip) ((ip)->vmt->getsize(ip))
/**
* @brief Returns the current file pointer position.
*
* @param[in] ip pointer to a @p FileStream or derived class
* @return The current position inside the file.
* @retval FILE_ERROR operation failed.
*
* @api
*/
#define fileStreamGetPosition(ip) ((ip)->vmt->getposition(ip))
/**
* @brief Moves the file current pointer to an absolute position.
*
* @param[in] ip pointer to a @p FileStream 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 fileStreamSeek(ip, offset) ((ip)->vmt->lseek(ip, offset))
/** @} */
#endif /* _HAL_FILES_H_ */
/** @} */