Ring buffer library

The ring buffer library implements ring (circular) buffer where bytes can be read and written independently. More...

Files
file	ringbuf.h
	Header file for the ring buffer library

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

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

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

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 102 of file ringbuf.c.

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 72 of file ringbuf.c.

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

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 43 of file ringbuf.c.

Referenced by uart0_init(), and uart1_init().

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 52 of file ringbuf.c.

Referenced by serial_line_input_byte().

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 96 of file ringbuf.c.