ringbuffer.h File Reference

Detailed Description

Exported symbols from ringbuffer.c.

Functions
struct ringbuffer *	ringbuffer_new (unsigned size)
void *	ringbuffer_add (struct ringbuffer *rb, void *data)
void *	ringbuffer_get (struct ringbuffer *rb, int num)
unsigned	ringbuffer_filled (struct ringbuffer *rb)
void	ringbuffer_flush (struct ringbuffer *rb, void(*free_func)(void *))

Function Documentation

ringbuffer_new()

struct ringbuffer* ringbuffer_new

(

unsigned

size

)

Initialize a new ringbuffer.

Parameters

size	The number of entries the ringbuffer holds.

This function initializes a circular buffer which can store up to the given number of entries. The entries can be of arbitrary type. Each ringbuffer is identified by an opaque handle which is returned by this function.

Returns

An opaque handle which identifies the new ringbuffer. Other functions of the ringbuffer API such as to ringbuffer_add() and ringbuffer_get() take a handle as their first argument.

ringbuffer_add()

void* ringbuffer_add	(	struct ringbuffer *	rb,
		void *	data
	)

Add an entry to a ringbuffer.

Parameters

rb	The handle which identifies the ringbuffer instance.
data	Pointer to the data to be inserted.

If the ringbuffer is full, the data pointer of the oldest entry is replaced by the given pointer.

Returns

The data pointer which is was disregarded, or NULL if the ringbuffer was not full yet.

ringbuffer_get()

void* ringbuffer_get	(	struct ringbuffer *	rb,
		int	num
	)

Get one entry from a ringbuffer.

Parameters

rb	The handle which identifies the ringbuffer instance.
num	The number of the entry.

Returns

A pointer to data previously added, or NULL if there is no entry corresponding to the given number. The number counts entries starting at the newest entry so that ringbuffer_get_entry(rb, 0) gets the entry which was added most recently.

ringbuffer_filled()

unsigned ringbuffer_filled

(

struct ringbuffer *

rb

)

Get the number of entries in the ringbuffer.

Parameters

rb	The handle which identifies the ringbuffer instance.

Returns

This function always succeeds and returns a number between zero and one less than the size of the ringbuffer, inclusively.

ringbuffer_flush()

void ringbuffer_flush	(	struct ringbuffer *	rb,
		void(*)(void *)	free_func
	)

Remove all entries from a ringbuffer.

Parameters

rb	The handle which identifies the ringbuffer instance.
free_func	Called on each existing entry.