/*
queue.c
Pedro Flynn - pflynn@microsoftsucks.org
*/

#include "queue.h"

Queue* queue_create()
{
Queue* new_queue;

new_queue = (Queue*) malloc(sizeof(Queue));

new_queue->q_size = 0;
new_queue->q_first = new_queue->q_last = NULL;

return new_queue;
	
}


int queue_enqueue(Queue* queue,void* data)
{
QueueElmt* new_element;

new_element = (QueueElmt*) malloc(sizeof(QueueElmt));
new_element->qe_data = data;

if(!queue->q_first)
	queue->q_first = new_element;
else
	queue->q_last->qe_next = new_element;

queue->q_last = new_element;
 
new_element->qe_next = NULL;
queue->q_size++;
return 0;
}

int queue_dequeue(Queue* queue,void** data)
{
	QueueElmt* element;
	
	if(!queue->q_size)
		return -1;
	
	element = queue->q_first;
	*data = element->qe_data;
	
	if(queue->q_first->qe_next)
		queue->q_first = queue->q_first->qe_next;
	else
		queue->q_last = queue->q_first = NULL;
	
	free(element);
	queue->q_size--;
	return 0;
}

int queue_empty(Queue* queue)
{
void* data;

	if(!queue->q_size)
	  return -1;

while(!queue_dequeue(queue,&data))
	free(data);
return 0;
}

int queue_destroy(Queue* queue)
{
	
queue_empty(queue);
free(queue);

return 0;
}

void queue_print(Queue* queue)
{
QueueElmt* element;
	
if(!queue->q_size)
	return;

element = queue->q_first;
do
fprintf(stdout,"%f\n",*((float*) element->qe_data));
while(element = element->qe_next);
}