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/*
ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS 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 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 chstreams.h
* @brief Data streams.
* @details This header defines abstract interfaces useful to access generic
* data streams in a standardized way.
*
* @addtogroup data_streams
* @details This module define an abstract interface for generic data streams.
* Note that no code is present, just abstract interfaces-like
* structures, you should look at the system as to a set of
* abstract C++ classes (even if written in C). This system
* has then advantage to make the access to data streams
* independent from the implementation logic.<br>
* The stream interface can be used as base class for high level
* object types such as files, sockets, serial ports, pipes etc.
* @{
*/
#ifndef _CHSTREAMS_H_
#define _CHSTREAMS_H_
/**
* @brief BaseSequentialStream specific methods.
*/
#define _base_sequential_stream_methods \
/* Stream write buffer method.*/ \
size_t (*write)(void *instance, const uint8_t *bp, size_t n); \
/* Stream read buffer method.*/ \
size_t (*read)(void *instance, uint8_t *bp, size_t n); \
/* Channel put method, blocking.*/ \
msg_t (*put)(void *instance, uint8_t b); \
/* Channel get method, blocking.*/ \
msg_t (*get)(void *instance); \
/**
* @brief @p BaseSequentialStream specific data.
* @note It is empty because @p BaseSequentialStream is only an interface
* without implementation.
*/
#define _base_sequential_stream_data
/**
* @brief @p BaseSequentialStream virtual methods table.
*/
struct BaseSequentialStreamVMT {
_base_sequential_stream_methods
};
/**
* @brief Base stream class.
* @details This class represents a generic blocking unbuffered sequential
* data stream.
*/
typedef struct {
/** @brief Virtual Methods Table.*/
const struct BaseSequentialStreamVMT *vmt;
_base_sequential_stream_data
} BaseSequentialStream;
/**
* @name Macro Functions (BaseSequentialStream)
* @{
*/
/**
* @brief Sequential Stream write.
* @details The function writes data from a buffer to a stream.
*
* @param[in] ip pointer to a @p BaseSequentialStream 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.
*
* @api
*/
#define chSequentialStreamWrite(ip, bp, n) ((ip)->vmt->write(ip, bp, n))
/**
* @brief Sequential Stream read.
* @details The function reads data from a stream into a buffer.
*
* @param[in] ip pointer to a @p BaseSequentialStream 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.
*
* @api
*/
#define chSequentialStreamRead(ip, bp, n) ((ip)->vmt->read(ip, bp, n))
/**
* @brief Sequential 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 BaseSequentialStream or derived class
* @param[in] b the byte value to be written to the channel
*
* @return The operation status.
* @retval Q_OK if the operation succeeded.
* @retval Q_RESET if an end-of-file condition has been met.
*
* @api
*/
#define chSequentialStreamPut(ip, b) ((ip)->vmt->put(ip, b))
/**
* @brief Sequential 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 BaseSequentialStream or derived class
*
* @return A byte value from the queue.
* @retval Q_RESET if an end-of-file condition has been met.
*
* @api
*/
#define chSequentialStreamGet(ip) ((ip)->vmt->get(ip))
/** @} */
#endif /* _CHSTREAMS_H_ */
/** @} */
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