contiki/core/lib/ringbufindex.h

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2015-09-21 16:21:55 +00:00
/*
* Copyright (c) 2015, SICS Swedish ICT.
* 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
* Header file for the ringbufindex library
* \author
* Simon Duquennoy <simonduq@sics.se>
*/
#ifndef __RINGBUFINDEX_H__
#define __RINGBUFINDEX_H__
#include "contiki-conf.h"
struct ringbufindex {
uint8_t mask;
/* These must be 8-bit quantities to avoid race conditions. */
uint8_t put_ptr, get_ptr;
};
/**
* \brief Initialize a ring buffer. The size must be a power of two
* \param r Pointer to ringbufindex
* \param size Size of ring buffer
*/
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void ringbufindex_init(struct ringbufindex *r, uint8_t size);
/**
* \brief Put one element to the ring buffer
* \param r Pointer to ringbufindex
* \retval 0 Failure; the ring buffer is full
* \retval 1 Success; an element is added
*/
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int ringbufindex_put(struct ringbufindex *r);
/**
* \brief Check if there is space to put an element.
* \param r Pinter to ringbufindex
* \retval >= 0 The index where the next element is to be added.
* \retval -1 Failure; the ring buffer is full
*/
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int ringbufindex_peek_put(const struct ringbufindex *r);
/**
* \brief Remove the first element and return its index
* \param r Pinter to ringbufindex
* \retval >= 0 The index of the first element
* \retval -1 No element in the ring buffer
*/
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int ringbufindex_get(struct ringbufindex *r);
/**
* \brief Return the index of the first element which will be removed if calling
* ringbufindex_get.
* \param r Pinter to ringbufindex
* \retval >= 0 The index of the first element
* \retval -1 No element in the ring buffer
*/
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int ringbufindex_peek_get(const struct ringbufindex *r);
/**
* \brief Return the ring buffer size
* \param r Pinter to ringbufindex
* \return The size of the ring buffer
*/
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int ringbufindex_size(const struct ringbufindex *r);
/**
* \brief Return the number of elements currently in the ring buffer.
* \param r Pinter to ringbufindex
* \return The number of elements in the ring buffer
*/
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int ringbufindex_elements(const struct ringbufindex *r);
/**
* \brief Is the ring buffer full?
* \retval 0 Not full
* \retval 1 Full
*/
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int ringbufindex_full(const struct ringbufindex *r);
/**
* \brief Is the ring buffer empty?
* \retval 0 Not empty
* \retval 1 Empty
*/
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int ringbufindex_empty(const struct ringbufindex *r);
#endif /* __RINGBUFINDEX_H__ */