76 lines
2.0 KiB
C
76 lines
2.0 KiB
C
#include "ringbuffer.h"
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/**
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* @file
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* Implementation of ring buffer functions.
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*/
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void ring_buffer_init(ring_buffer_t *buffer) {
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buffer->tail_index = 0;
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buffer->head_index = 0;
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}
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void ring_buffer_queue(ring_buffer_t *buffer, uint8_t data) {
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/* Is buffer full? */
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if(ring_buffer_is_full(buffer)) {
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/* Is going to overwrite the oldest byte */
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/* Increase tail index */
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buffer->tail_index = ((buffer->tail_index + 1) & RING_BUFFER_MASK);
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}
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/* Place data in buffer */
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buffer->buffer[buffer->head_index] = data;
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buffer->head_index = ((buffer->head_index + 1) & RING_BUFFER_MASK);
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}
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void ring_buffer_queue_arr(ring_buffer_t *buffer, const uint8_t *data, ring_buffer_size_t size) {
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/* Add bytes; one by one */
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ring_buffer_size_t i;
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for(i = 0; i < size; i++) {
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ring_buffer_queue(buffer, data[i]);
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}
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}
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ring_buffer_size_t ring_buffer_dequeue(ring_buffer_t *buffer, uint8_t *data) {
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if(ring_buffer_is_empty(buffer)) {
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/* No items */
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return 0;
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}
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*data = buffer->buffer[buffer->tail_index];
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buffer->tail_index = ((buffer->tail_index + 1) & RING_BUFFER_MASK);
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return 1;
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}
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ring_buffer_size_t ring_buffer_dequeue_arr(ring_buffer_t *buffer, uint8_t *data, ring_buffer_size_t len) {
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if(ring_buffer_is_empty(buffer)) {
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/* No items */
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return 0;
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}
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uint8_t *data_ptr = data;
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ring_buffer_size_t cnt = 0;
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while((cnt < len) && ring_buffer_dequeue(buffer, data_ptr)) {
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cnt++;
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data_ptr++;
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}
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return cnt;
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}
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ring_buffer_size_t ring_buffer_peek(ring_buffer_t *buffer, uint8_t *data, ring_buffer_size_t index) {
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if(index >= ring_buffer_num_items(buffer)) {
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/* No items at index */
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return 0;
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}
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/* Add index to pointer */
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ring_buffer_size_t data_index = ((buffer->tail_index + index) & RING_BUFFER_MASK);
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*data = buffer->buffer[data_index];
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return 1;
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}
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extern inline ring_buffer_size_t ring_buffer_is_empty(ring_buffer_t *buffer);
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extern inline ring_buffer_size_t ring_buffer_is_full(ring_buffer_t *buffer);
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extern inline ring_buffer_size_t ring_buffer_num_items(ring_buffer_t *buffer);
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