queue.h

/*
 * File: queue.h
 * Author: Chris Wailes <chris.wailes@gmail.com>
 * Author: Wei-Te Chen <weite.chen@colorado.edu>
 * Author: Andy Sayler <andy.sayler@gmail.com>
 * Project: CSCI 3753 Programming Assignment 2
 * Create Date: 2010/02/12
 * Modify Date: 2011/02/05
 * Modify Date: 2012/02/01
 * Description:
 * 	This is the header file for an implemenation of a simple FIFO queue.
 * 
 */

#ifndef QUEUE_H
#define QUEUE_H

#include <stdio.h>

#define QUEUEMAXSIZE 50

#define QUEUE_FAILURE -1
#define QUEUE_SUCCESS 0

typedef struct queue_node_s{
    void* payload;
} queue_node;

typedef struct queue_s{
    queue_node* array;
    int front;
    int rear;
    int maxSize;
} queue;

/* Function to initilze a new queue
 * On success, returns queue size
 * On failure, returns QUEUE_FAILURE
 * Must be called before queue is used
 */
int queue_init(queue* q, int size);

/* Function to test if queue is empty
 * Returns 1 if empty, 0 otherwise
 */
int queue_is_empty(queue* q);

/* Function to test if queue is full
 * Returns 1 if full, 0 otherwise
 */
int queue_is_full(queue* q);

/* Function add payload to end of FIFO queue
 * Returns QUEUE_SUCCESS if the push successeds.
 * Returns QUEUE_FAILURE if the push fails
 */
int queue_push(queue* q, void* payload);

/* Function to return element from queue in FIFO order
 * Returns NULL pointer if queue is empty
 */
void* queue_pop(queue* q);

/* Function to free queue memory */
void queue_cleanup(queue* q);

#endif