fifo.c

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#include "fifo_private.h"

void fifo_init(scpi_fifo_t * fifo, scpi_error_t * data, int16_t size) {
    fifo->wr = 0;
    fifo->rd = 0;
    fifo->count = 0;
    fifo->data = data;
    fifo->size = size;
}

void fifo_clear(scpi_fifo_t * fifo) {
    fifo->wr = 0;
    fifo->rd = 0;
    fifo->count = 0;
}

scpi_bool_t fifo_is_empty(scpi_fifo_t * fifo) {
    return fifo->count == 0;
}

scpi_bool_t fifo_is_full(scpi_fifo_t * fifo) {
    return fifo->count == fifo->size;
}

scpi_bool_t fifo_add(scpi_fifo_t * fifo, const scpi_error_t * value) {
    /* FIFO full? */
    if (fifo_is_full(fifo)) {
        return FALSE;
    }
    if (!value) {
        return FALSE;
    }
 
    fifo->data[fifo->wr] = *value;
    fifo->wr = (fifo->wr + 1) % (fifo->size);
    fifo->count += 1;
    return TRUE;
}

scpi_bool_t fifo_remove(scpi_fifo_t * fifo, scpi_error_t * value) {
    /* FIFO empty? */
    if (fifo_is_empty(fifo)) {
        return FALSE;
    }
 
    if (value) {
        *value = fifo->data[fifo->rd];
    }
 
    fifo->rd = (fifo->rd + 1) % (fifo->size);
    fifo->count -= 1;
 
    return TRUE;
}

scpi_bool_t fifo_remove_last(scpi_fifo_t * fifo, scpi_error_t * value) {
    /* FIFO empty? */
    if (fifo_is_empty(fifo)) {
        return FALSE;
    }
 
    fifo->wr = (fifo->wr + fifo->size - 1) % (fifo->size);
 
    if (value) {
        *value = fifo->data[fifo->wr];
    }
    fifo->count -= 1;
 
    return TRUE;
}

scpi_bool_t fifo_count(scpi_fifo_t * fifo, int16_t * value) {
    *value = fifo->count;
    return TRUE;
}