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C

/**
* \file
*
* \brief Ringbuffer functionality implementation.
*
* Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries.
*
* \asf_license_start
*
* \page License
*
* Subject to your compliance with these terms, you may use Microchip
* software and any derivatives exclusively with Microchip products.
* It is your responsibility to comply with third party license terms applicable
* to your use of third party software (including open source software) that
* may accompany Microchip software.
*
* THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES,
* WHETHER EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE,
* INCLUDING ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY,
* AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL MICROCHIP BE
* LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, INCIDENTAL OR CONSEQUENTIAL
* LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND WHATSOEVER RELATED TO THE
* SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS BEEN ADVISED OF THE
* POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO THE FULLEST EXTENT
* ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY
* RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY,
* THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
*
* \asf_license_stop
*
*/
#include "utils_ringbuffer.h"
/**
* \brief Ringbuffer init
*/
int32_t ringbuffer_init(struct ringbuffer *const rb, void *buf, uint32_t size)
{
ASSERT(rb && buf && size);
/*
* buf size must be aligned to power of 2
*/
if ((size & (size - 1)) != 0) {
return ERR_INVALID_ARG;
}
/* size - 1 is faster in calculation */
rb->size = size - 1;
rb->read_index = 0;
rb->write_index = rb->read_index;
rb->buf = (uint8_t *)buf;
return ERR_NONE;
}
/**
* \brief Get one byte from ringbuffer
*
*/
int32_t ringbuffer_get(struct ringbuffer *const rb, uint8_t *data)
{
ASSERT(rb && data);
if (rb->write_index != rb->read_index) {
*data = rb->buf[rb->read_index & rb->size];
rb->read_index++;
return ERR_NONE;
}
return ERR_NOT_FOUND;
}
/**
* \brief Put one byte to ringbuffer
*
*/
int32_t ringbuffer_put(struct ringbuffer *const rb, uint8_t data)
{
ASSERT(rb);
rb->buf[rb->write_index & rb->size] = data;
/*
* buffer full strategy: new data will overwrite the oldest data in
* the buffer
*/
if ((rb->write_index - rb->read_index) > rb->size) {
rb->read_index = rb->write_index - rb->size;
}
rb->write_index++;
return ERR_NONE;
}
/**
* \brief Return the element number of ringbuffer
*/
uint32_t ringbuffer_num(const struct ringbuffer *const rb)
{
ASSERT(rb);
return rb->write_index - rb->read_index;
}
/**
* \brief Flush ringbuffer
*/
uint32_t ringbuffer_flush(struct ringbuffer *const rb)
{
ASSERT(rb);
rb->read_index = rb->write_index;
return ERR_NONE;
}