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#include "fifo_private.h"
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/**
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* Initialize fifo
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* @param fifo
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*/
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void fifo_init(scpi_fifo_t * fifo) {
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fifo->wr = 0;
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fifo->rd = 0;
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fifo->size = FIFO_SIZE;
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}
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/**
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* Empty fifo
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* @param fifo
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*/
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void fifo_clear(scpi_fifo_t * fifo) {
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fifo->wr = 0;
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fifo->rd = 0;
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}
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/**
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* Add element to fifo. If fifo is full, remove last element.
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* @param fifo
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* @param value
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* @return
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*/
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scpi_bool_t fifo_add(scpi_fifo_t * fifo, int16_t value) {
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/* FIFO full? */
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if (fifo->wr == ((fifo->rd + fifo->size) % (fifo->size + 1))) {
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fifo_remove(fifo, NULL);
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}
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fifo->data[fifo->wr] = value;
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fifo->wr = (fifo->wr + 1) % (fifo->size + 1);
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return TRUE;
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}
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/**
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* Remove element form fifo
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* @param fifo
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* @param value
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* @return FALSE - fifo is empty
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*/
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scpi_bool_t fifo_remove(scpi_fifo_t * fifo, int16_t * value) {
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/* FIFO empty? */
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if (fifo->wr == fifo->rd) {
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return FALSE;
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}
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if (value) {
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*value = fifo->data[fifo->rd];
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}
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fifo->rd = (fifo->rd + 1) % (fifo->size + 1);
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return TRUE;
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}
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/**
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* Retrive number of elements in fifo
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* @param fifo
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* @param value
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* @return
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*/
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scpi_bool_t fifo_count(scpi_fifo_t * fifo, int16_t * value) {
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*value = fifo->wr - fifo->rd;
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if (*value < 0) {
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*value += (fifo->size + 1);
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}
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return TRUE;
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}
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