rbuf.h

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#ifndef EVE_RBUF_H_INCLUDED
#define EVE_RBUF_H_INCLUDED

/**********************************************************************/
/*
 * Copyright (c) 2008, 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.
 *
 */

 /**
 * \file
 * \brief Header file for ring buffer primitive library
 *
 * \author Adam Dunkels <adam@sics.se>
 * \author SB, Jetro AS
 */ /******************************************************************/

#include <stdint.h>
#include <stdbool.h>

/**
 * \defgroup rbuf Ring buffer
 * \ingroup util
 * \{
 */

/**
 * \brief      Structure that holds the state of a ring buffer.
 *
 *             This structure holds the state of a ring buffer. The
 *             actual buffer needs to be defined separately. This
 *             struct is an opaque structure with no user-visible
 *             elements.
 *
 */
struct rbuf_t {
  uint8_t *data;
  uint32_t size;
  uint32_t put;
  uint32_t get;
};

/**
 * \brief      Initialize a ring buffer
 * \param r    A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param a    A pointer to an array to hold the data in the buffer
 * \param size The size of the ring buffer
 *
 *             This function initiates a ring buffer. The data in the
 *             buffer is stored in an external array, to which a
 *             pointer must be supplied.
 *
 */
void rbuf_init(struct rbuf_t *r, uint8_t *a, uint32_t size);

/**
 * \brief      Get the size of a ring buffer
 * \param r    A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \return     The size of the buffer.
 */
uint32_t rbuf_size(struct rbuf_t *r);

/**
 * \brief      Get the number of bytes currently used in the ring buffer
 * \param r    A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \return     The number of elements in the buffer.
 */
uint32_t rbuf_used(struct rbuf_t *r);

/**
 * \brief       Get the length of a continuous used part of the buffer and a pointer to its beginning
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param[out] ptr Pointer to the pointer to the beginning of a continuous used part
 * \return      The length of a continuous used part of the buffer
 */
uint32_t rbuf_contused(struct rbuf_t *r, uint8_t** ptr);

/**
 * \brief       Advance the read pointer of the buffer after direct read. Note that
 *              length cannot be larger than the value returned by rbuf_contused()
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param l     Number of bytes read
 */
void     rbuf_commitread(struct rbuf_t *r, uint32_t l);

/**
 * \brief       Get the number of free bytes currently in the ring buffer
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \return      The number of free bytes in the buffer.
 */
uint32_t rbuf_free(struct rbuf_t *r);

/**
 * \brief       Get the length of a continuous free part of the buffer and a pointer to its beginning
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param[out] ptr Pointer to the pointer to the beginning of a continuous free part
 * \return      The length of a continuous free part of the buffer
 */
uint32_t rbuf_contfree(struct rbuf_t *r, uint8_t** ptr);

/**
 * \brief       Advance the write pointer of the buffer after direct write. Note that
 *              length cannot be larger than the value returned by rbuf_contfree()
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param l     Number of bytes written
 */
void     rbuf_commitwrite(struct rbuf_t *r, uint32_t l);

/**
 * \brief       Put an array of bytes to the ring buffer
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param a     A pointer to an array to copy data from
 * \param l     Number of bytes to put
 * \return      true on success, false if there is not enough free space in the buffer
 */
bool rbuf_push(struct rbuf_t *r, const uint8_t* a, uint32_t l);

/**
 * \brief       Get an array of bytes from the ring buffer
 * \param r     A pointer to a struct rbuf_t to hold the state of the ring buffer
 * \param a     A pointer to an array to copy data to
 * \param l     Number of bytes to get
 * \return      true on success, false if there is not enough bytes in the buffer
 */
bool rbuf_pull(struct rbuf_t *r, uint8_t* a, uint32_t l);

/** @} rbuf */

#endif /* EVE_RBUF_H_INCLUDED */