A queue that is implemented as a ring buffer. More...

Data Structures
struct	util_ringqueue
	Structure for the ringqueue, see also ringqueue. More...

Macros
#define	util_ringqueue_foreach(i, queue) for (i = util_ringqueue_index_first(queue); i != -1; i = util_ringqueue_index_next(queue, i))
	Foreach loop for iterating through a ringqueue.

Functions
int	util_ringqueue_size (int num_elements)
	Computes the size in bytes for `num_elements` ringqueue entries. More...

void	util_ringqueue_init (struct util_ringqueue queue, void data, int size)
	Initializes a ringqueue. More...

void *	util_ringqueue_clear (struct util_ringqueue *queue)
	Clear the ringqueue `queue`. More...

unsigned int	util_ringqueue_count (struct util_ringqueue *queue)
	Get the current number of elements in a ringqueue.

bool	util_ringqueue_full (struct util_ringqueue *queue)
	Test if the ringqueue `queue` is full. More...

unsigned int	util_ringqueue_max (struct util_ringqueue *queue)
	Get the maximum capacity of a queue.

int	util_ringqueue_put_front (struct util_ringqueue queue, void data)
	Insert an element `data` at the front of the ringqueue `queue`. More...

int	util_ringqueue_put_end (struct util_ringqueue queue, void data)
	Insert an element `data` at the end of the ringqueue `queue`. More...

void *	util_ringqueue_pop_front (struct util_ringqueue *queue)
	Remove an element at the front of the ringqueue `queue`. More...

void *	util_ringqueue_pop_end (struct util_ringqueue *queue)
	Remove an element at the end of the ringqueue `queue`. More...

int	util_ringqueue_index_first (struct util_ringqueue *queue)
	Get the index to the first element of the queue. More...

int	util_ringqueue_index_next (struct util_ringqueue *queue, int idx)
	Get the index to the next element of the queue. More...

void *	util_ringqueue_get_index (struct util_ringqueue *queue, int idx)
	Get the element at a given index `idx` of the queue. More...

void *	util_ringqueue_get_front (struct util_ringqueue *queue)
	Get the element at the front of the queue. More...

void *	util_ringqueue_get_end (struct util_ringqueue *queue)
	Get the element at the end of the queue. More...

Detailed Description

A queue that is implemented as a ring buffer.

Allows to store arbitrary number of elements, however internal buffer must be provided by user. It is possible to add and remove elements at front and back of the queue.

Function Documentation

void* util_ringqueue_clear ( struct util_ringqueue * queue )

Clear the ringqueue queue.

Returns: The data pointer that was given to util_ringqueue_init, as it might need to be freed.

bool util_ringqueue_full ( struct util_ringqueue * queue )

Test if the ringqueue queue is full.

Returns: True if no further elements can be added.

void* util_ringqueue_get_end ( struct util_ringqueue * queue )

Get the element at the end of the queue.

Returns: Pointer to last element or NULL if queue is empty.

void* util_ringqueue_get_front ( struct util_ringqueue * queue )

Get the element at the front of the queue.

Returns: Pointer to first element or NULL if queue is empty.

void* util_ringqueue_get_index	(	struct util_ringqueue *	queue,
		int	idx
	)

Get the element at a given index idx of the queue.

Returns: Pointer to element at index or NULL if queue is empty.

int util_ringqueue_index_first ( struct util_ringqueue * queue )

Get the index to the first element of the queue.

Returns: Index or negative errorcode if queue is empty.

int util_ringqueue_index_next	(	struct util_ringqueue *	queue,
		int	idx
	)

Get the index to the next element of the queue.

Returns: Index or negative errorcode if queue is empty.

void util_ringqueue_init	(	struct util_ringqueue *	queue,
		void *	data,
		int	size
	)

Initializes a ringqueue.

Parameters

queue	The ringqueue context.
data	Pointer to preallocated memory to use for the ringqueue.
size	Size of `data` in bytes, see util_list_size.

void* util_ringqueue_pop_end ( struct util_ringqueue * queue )

Remove an element at the end of the ringqueue queue.

Returns: Pointer to element that was removed or NULL when queue is empty.

void* util_ringqueue_pop_front ( struct util_ringqueue * queue )

Remove an element at the front of the ringqueue queue.

Returns: Pointer to element that was removed or NULL when queue is empty.

int util_ringqueue_put_end	(	struct util_ringqueue *	queue,
		void *	data
	)

Insert an element data at the end of the ringqueue queue.

Returns: Zero on success or errorcode on failure.

int util_ringqueue_put_front	(	struct util_ringqueue *	queue,
		void *	data
	)

Insert an element data at the front of the ringqueue queue.

Returns: Zero on success or errorcode on failure.

int util_ringqueue_size ( int num_elements )

Computes the size in bytes for num_elements ringqueue entries.

This can be used by the called to allocate the correct amount of memory for util_ringqueue_init.

Data Structures

Macros

Functions

Detailed Description

Function Documentation