Ring buffer library

Data Structures
struct	ringbuf
	Structure that holds the state of a ring buffer. More...

Functions
static void	ringbuf_init (struct ringbuf *r, uint8_t *a, uint8_t size_power_of_two)
	Initialize a ring buffer.
int	ringbuf_put (struct ringbuf *r, uint8_t c)
	Insert a byte into the ring buffer.
int	ringbuf_get (struct ringbuf *r)
	Get a byte from the ring buffer.
int	ringbuf_size (struct ringbuf *r)
	Get the size of a ring buffer.
int	ringbuf_elements (struct ringbuf *r)
	Get the number of elements currently in the ring buffer.

Detailed Description

The ring buffer library implements ring (circular) buffer where bytes can be read and written independently. A ring buffer is particularly useful in device drivers where data can come in through interrupts.

Function Documentation

ringbuf_elements()

int ringbuf_elements

(

struct ringbuf *

r

)

Get the number of elements currently in the ring buffer.

Parameters

r	A pointer to a struct ringbuf to hold the state of the ring buffer

Returns

The number of elements in the buffer.

Definition at line 110 of file ringbuf.c.

ringbuf_get()

int ringbuf_get

(

struct ringbuf *

r

)

Get a byte from the ring buffer.

Parameters

r	A pointer to a struct ringbuf to hold the state of the ring buffer

Returns

The data from the buffer, or -1 if the buffer was empty

        This function removes a byte from the ring buffer. It
        is safe to call this function from an interrupt
        handler.

Definition at line 71 of file ringbuf.c.

References CC_ACCESS_NOW.

ringbuf_init()

static void ringbuf_init ( struct ringbuf * r, uint8_t * a, uint8_t size_power_of_two )

inlinestatic

Initialize a ring buffer.

Parameters

r	A pointer to a struct ringbuf to hold the state of the ring buffer
a	A pointer to an array to hold the data in the buffer
size_power_of_two	The size of the ring buffer, which must be a power of two This function initiates a ring buffer. The data in the buffer is stored in an external array, to which a pointer must be supplied. The size of the ring buffer must be a power of two and cannot be larger than 128 bytes.

Definition at line 90 of file ringbuf.h.

Referenced by uart0_init(), and uart1_init().

ringbuf_put()

int ringbuf_put	(	struct ringbuf *	r,
		uint8_t	c )

Insert a byte into the ring buffer.

Parameters

r	A pointer to a struct ringbuf to hold the state of the ring buffer
c	The byte to be written to the buffer

Returns

Non-zero if there data could be written, or zero if the buffer was full.

        This function inserts a byte into the ring buffer. It
        is safe to call this function from an interrupt
        handler.

Definition at line 44 of file ringbuf.c.

References CC_ACCESS_NOW.

Referenced by serial_line_input_byte().

ringbuf_size()

int ringbuf_size

(

struct ringbuf *

r

)

Get the size of a ring buffer.

Parameters

r	A pointer to a struct ringbuf to hold the state of the ring buffer

Returns

The size of the buffer.

Definition at line 104 of file ringbuf.c.