satellite-testing-system/Core/Src/ringbuffer.c

112 lines
3.5 KiB
C

#include "ringbuffer.h"
/**
* @file
* Implementation of ring buffer functions.
*
* The MIT License (MIT)
*
* Copyright (c) 2014 Anders Kalør
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
void ring_buffer_init(ring_buffer_t *buffer, uint8_t *buf, size_t buf_size)
{
RING_BUFFER_ASSERT(RING_BUFFER_IS_POWER_OF_TWO(buf_size) == 1);
buffer->buffer = buf;
buffer->buffer_mask = buf_size - 1;
buffer->tail_index = 0;
buffer->head_index = 0;
}
void ring_buffer_queue(ring_buffer_t *buffer, uint8_t data)
{
/* Is buffer full? */
if (ring_buffer_is_full(buffer))
{
/* Is going to overwrite the oldest byte */
/* Increase tail index */
buffer->tail_index = ((buffer->tail_index + 1) & RING_BUFFER_MASK(buffer));
}
/* Place data in buffer */
buffer->buffer[buffer->head_index] = data;
buffer->head_index = ((buffer->head_index + 1) & RING_BUFFER_MASK(buffer));
}
void ring_buffer_queue_arr(ring_buffer_t *buffer, const uint8_t *data, ring_buffer_size_t size)
{
/* Add bytes; one by one */
ring_buffer_size_t i;
for (i = 0; i < size; i++)
{
ring_buffer_queue(buffer, data[i]);
}
}
uint8_t ring_buffer_dequeue(ring_buffer_t *buffer, uint8_t *data)
{
if (ring_buffer_is_empty(buffer))
{
/* No items */
return 0;
}
*data = buffer->buffer[buffer->tail_index];
buffer->tail_index = ((buffer->tail_index + 1) & RING_BUFFER_MASK(buffer));
return 1;
}
ring_buffer_size_t ring_buffer_dequeue_arr(ring_buffer_t *buffer, uint8_t *data, ring_buffer_size_t len)
{
if (ring_buffer_is_empty(buffer))
{
/* No items */
return 0;
}
uint8_t *data_ptr = data;
ring_buffer_size_t cnt = 0;
while ((cnt < len) && ring_buffer_dequeue(buffer, data_ptr))
{
cnt++;
data_ptr++;
}
return cnt;
}
uint8_t ring_buffer_peek(ring_buffer_t *buffer, uint8_t *data, ring_buffer_size_t index)
{
if (index >= ring_buffer_num_items(buffer))
{
/* No items at index */
return 0;
}
/* Add index to pointer */
ring_buffer_size_t data_index = ((buffer->tail_index + index) & RING_BUFFER_MASK(buffer));
*data = buffer->buffer[data_index];
return 1;
}
extern inline uint8_t ring_buffer_is_empty(ring_buffer_t *buffer);
extern inline uint8_t ring_buffer_is_full(ring_buffer_t *buffer);
extern inline ring_buffer_size_t ring_buffer_num_items(ring_buffer_t *buffer);