/*
 * file: queue.c
 *
 * 	circular queue
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "queue.h"

void initFifoQ (struct fifo* queue) {
	int i;
	for (i=0; i<MAX_QUEUE_SIZE; i++) queue->data[i] =0;
	queue->size=0;
	queue->front=0;
	queue->back=0;
}

void addFifoQ (struct fifo* queue, int item){
	if (queue->size == MAX_QUEUE_SIZE) {
		size= -1; // error status
		printf(" ERROR: QUEUE OVERFLOW\n");
		return;
	}
	queue->data[queue->back]=i;
	queue->back = (queue->back + 1) % MAX_QUEUE_SIZE;
}

int emptyFifoQ (struct fifo* queue){		// zero out the queue
	return(queue->front == queue->back);
}
int popFifoQ (struct fifo*);		// return -1 if empty queue