queue.c

#include "queue.h"
#include <stdlib.h>


queue_t get_queue()
{
	//initializing an empty queue	
	queue_t ret = (queue_t)
	{
        element_queue: create_list(),
        start_time: 0,
    };

    return ret;
}


int queue_element(queue_t *queue, void* element, int current_time)
{
	//checking if the arguments are ok
	if( (!queue) || (!element) )
	{
		return FAILED_EXECUTION;
	}

	//if noone was in queue the new arrived presses the button
    if(queue_is_empty(queue))
	{
        queue->start_time = current_time;
    }
	
	//adding element to the queue
    add(queue->element_queue, element);

    return CORRECT_EXECUTION;
}

void *dequeue_element(queue_t *queue)
{
	if(!queue)
	{
		return NULL;
	}

    return remove_first(queue->element_queue);
}

void free_queue(queue_t* queue, void free_val(void*))
{
    free_linked_list(queue->element_queue, free_val);
}

int queue_is_empty(queue_t *queue)
{
	if(!queue)
	{
		return FAILED_EXECUTION;
	}

    return list_is_empty(queue->element_queue);
}

int queue_length(queue_t *queue){

	if(!queue)
	{
		return FAILED_EXECUTION;
	}

    return linked_list_length(queue->element_queue);
}