queue.c File Reference

#include <hal.h>
#include <libc.h>
#include <malloc.h>
#include <queue.h>

Functions
struct queue *	hf_queue_create (int32_t size)
	Creates a queue of specified size. More...
int32_t	hf_queue_destroy (struct queue *q)
	Destroys a queue. More...
int32_t	hf_queue_count (struct queue *q)
	Counts the number of nodes in a queue. More...
int32_t	hf_queue_addtail (struct queue *q, void *ptr)
	Adds a node to the tail of the queue. More...
void *	hf_queue_remhead (struct queue *q)
	Removes a node from the head of the queue. More...
void *	hf_queue_remtail (struct queue *q)
	Removes a node from the tail of the queue. More...
void *	hf_queue_get (struct queue *q, int32_t elem)
	Returns a node from the queue. More...
int32_t	hf_queue_set (struct queue *q, int32_t elem, void *ptr)
	Updates a node on the queue. More...
int32_t	hf_queue_swap (struct queue *q, int32_t elem1, int32_t elem2)
	Swap the position of two nodes in the queue. More...

Detailed Description

Author

Sergio Johann Filho

Date

February 2016

LICENSE

This source code is licensed under the GNU General Public License, Version 2. See the file 'doc/license/gpl-2.0.txt' for more details.

DESCRIPTION

Queue manipulation primitives and auxiliary functions. Queue structures are allocated only on the creation of queues, so little additional overhead regarding memory management is incurred at runtime.

Function Documentation

hf_queue_addtail()

int32_t hf_queue_addtail	(	struct queue *	q,
		void *	ptr
	)

Adds a node to the tail of the queue.

Parameters

q	is a pointer to a queue structure.
ptr	a pointer to data belonging to the queue node.

Returns

0 when successful and -1 otherwise.

hf_queue_count()

int32_t hf_queue_count

(

struct queue *

q

)

Counts the number of nodes in a queue.

Parameters

q	is a pointer to a queue structure.

Returns

the number of nodes.

hf_queue_create()

struct queue* hf_queue_create

(

int32_t

size

)

Creates a queue of specified size.

Parameters

size	is the maximum number of elements.

Returns

pointer to the queue on success and NULL otherwise.

hf_queue_destroy()

int32_t hf_queue_destroy

(

struct queue *

q

)

Destroys a queue.

Parameters

q	is a pointer to a queue structure.

Returns

0 when successful and -1 otherwise.

hf_queue_get()

void* hf_queue_get	(	struct queue *	q,
		int32_t	elem
	)

Returns a node from the queue.

Parameters

q	is a pointer to a queue structure.
elem	is the n-th element from the queue.

Returns

pointer to node data success and 0 otherwise.

hf_queue_remhead()

void* hf_queue_remhead

(

struct queue *

q

)

Removes a node from the head of the queue.

Parameters

q	is a pointer to a queue structure.

Returns

pointer to node data on success and 0 otherwise.

hf_queue_remtail()

void* hf_queue_remtail

(

struct queue *

q

)

Removes a node from the tail of the queue.

Parameters

q	is a pointer to a queue structure.

Returns

pointer to node data on success and 0 otherwise.

hf_queue_set()

int32_t hf_queue_set	(	struct queue *	q,
		int32_t	elem,
		void *	ptr
	)

Updates a node on the queue.

Parameters

q	is a pointer to a queue structure.
elem	is the n-th element from the queue.
ptr	a pointer to data belonging to the queue node.

Returns

0 success and -1 otherwise.

hf_queue_swap()

int32_t hf_queue_swap	(	struct queue *	q,
		int32_t	elem1,
		int32_t	elem2
	)

Swap the position of two nodes in the queue.

Parameters

q	is a pointer to a queue structure.
elem1	is the first n-th element from the queue.
elem2	is the second n-th element from the queue.

Returns

0 when successful and -1 otherwise.