queue.c File Reference

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

Data Structures
struct	queue_node
	Private. More...
Functions
void	queue_init (queue_t *q)
	Initializes queue structure.
void	queue_destroy (queue_t *q)
	Frees all associated memory.
void *	queue_dequeue (queue_t *q)
	Removes and returns element from front of queue.
void *	queue_remove_at (queue_t *q, int pos)
	Removes and returns element at position pos.
void *	queue_at (queue_t *q, int pos)
	Returns element located at position pos.
void	queue_enqueue (queue_t *q, void *item)
	Stores item at the back of the queue.
unsigned int	queue_size (queue_t *q)
	Returns number of items in the queue.
void	queue_iterate (queue_t *q, void(*iter_func)(void *, void *), void *arg)
	Helper function to apply operation on each item.

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Detailed Description

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Function Documentation

void* queue_at	(	queue_t *	q,
		int	pos
	)

Returns element located at position pos.

Parameters:

	q	A pointer to the queue data structure.
	pos	Zero-based index of element to return.

Returns:

A pointer to the element at position pos.

NULL if position out of bounds.

void* queue_dequeue

(

queue_t *

q

)

Removes and returns element from front of queue.

Parameters:

q

A pointer to the queue data structure.

Returns:

A pointer to the oldest element in the queue.

NULL if the queue is empty.

void queue_destroy

(

queue_t *

q

)

Frees all associated memory.

Should always be called last.

Parameters:

q

A pointer to the queue data structure.

Returns:

void

void queue_enqueue	(	queue_t *	q,
		void *	item
	)

Stores item at the back of the queue.

Parameters:

	q	A pointer to the queue data structure.
	item	Value of item to be stored.

Returns:

void

void queue_init

(

queue_t *

q

)

Initializes queue structure.

Should always be called first.

Parameters:

q

A pointer to the queue data structure.

Returns:

void

void queue_iterate	(	queue_t *	q,
		void(*)(void *, void *)	iter_func,
		void *	arg
	)

Helper function to apply operation on each item.

Parameters:

	q	A pointer to the queue data structure.
	iter_func	Function pointer to operation to be applied.
	arg	Pass through variable to iter_func.

Returns:

void

void* queue_remove_at	(	queue_t *	q,
		int	pos
	)

Removes and returns element at position pos.

Parameters:

	q	A pointer to the queue data structure.
	pos	Position to be removed.

Returns:

A pointer to the element at position pos.

NULL if the position is invalid.

unsigned int queue_size

(

queue_t *

q

)

Returns number of items in the queue.

Parameters:

q

A pointer to the queue data structure.

Returns:

The number of items in the queue.