ring_buffer.h File Reference

Simple circular buffer. More...

#include "hal_types.h"

Include dependency graph for ring_buffer.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	ring_buffer

Typedefs
typedef struct ring_buffer	ring_buffer

Functions
static void	rb_init (ring_buffer *rb, uint16_t size, uint8_t *buf)
static uint16_t	rb_full_count (ring_buffer *rb)
	Return the number of elements stored in the ring buffer. More...
static int	rb_is_full (ring_buffer *rb)
	Returns true if and only if the ring buffer is full. More...
static int	rb_is_empty (ring_buffer *rb)
	Returns true if and only if the ring buffer is empty. More...
static void	rb_insert (ring_buffer *rb, uint8_t element)
static uint8_t	rb_remove (ring_buffer *rb)
	Remove and return the first item from a ring buffer. More...
static int16_t	rb_safe_remove (ring_buffer *rb)
	Attempt to remove the first item from a ring buffer. More...
static int	rb_safe_insert (ring_buffer *rb, uint8_t element)
	Attempt to insert an element into a ring buffer. More...
static int	rb_push_insert (ring_buffer *rb, uint8_t element)
	Append an item onto the end of a non-full ring buffer. More...
static void	rb_reset (ring_buffer *rb)
	Discard all items from a ring buffer. More...

Detailed Description

Simple circular buffer.

This implementation is not thread-safe. In particular, none of these functions is guaranteed re-entrant.

Definition in file ring_buffer.h.

Typedef Documentation

ring_buffer

typedef struct ring_buffer ring_buffer

Ring buffer type.

The buffer is empty when head == tail.

The buffer is full when the head is one byte in front of the tail, modulo buffer length.

One byte is left free to distinguish empty from full.

Function Documentation

rb_full_count()

static uint16_t rb_full_count ( ring_buffer *  rb )

inlinestatic

Return the number of elements stored in the ring buffer.

Parameters

rb	Buffer whose elements to count.

Definition at line 84 of file ring_buffer.h.

Referenced by F4Light::UART_PPM::available(), usart_data_available(), usart_txfifo_freebytes(), and usart_txfifo_nbytes().

Here is the caller graph for this function:

rb_init()

static void rb_init ( ring_buffer *  rb, uint16_t  size, uint8_t *  buf  )

inlinestatic

Initialise a ring buffer.

Parameters

rb	Instance to initialise
size	Number of items in buf. The ring buffer will always leave one element unoccupied, so the maximum number of elements it can store will be size - 1. Thus, size must be at least 2.
buf	Buffer to store items into

Definition at line 73 of file ring_buffer.h.

Referenced by F4Light::UART_PPM::UART_PPM(), usart_setup(), and VCP_Init().

Here is the caller graph for this function:

rb_insert()

static void rb_insert ( ring_buffer *  rb, uint8_t  element  )

inlinestatic

Append element onto the end of a ring buffer.

Parameters

rb	Buffer to append onto.
element	Value to append.

Definition at line 118 of file ring_buffer.h.

Referenced by rb_push_insert(), rb_safe_insert(), and usart_tx().

Here is the caller graph for this function:

rb_is_empty()

static int rb_is_empty ( ring_buffer *  rb )

inlinestatic

Returns true if and only if the ring buffer is empty.

Parameters

rb	Buffer to test.

Definition at line 109 of file ring_buffer.h.

Referenced by rb_safe_remove(), and usart_tx_irq().

Here is the caller graph for this function:

rb_is_full()

static int rb_is_full ( ring_buffer *  rb )

inlinestatic

Returns true if and only if the ring buffer is full.

Parameters

rb	Buffer to test.

Definition at line 99 of file ring_buffer.h.

Referenced by rb_push_insert(), rb_safe_insert(), and usart_tx().

Here is the caller graph for this function:

rb_push_insert()

static int rb_push_insert ( ring_buffer *  rb, uint8_t  element  )

inlinestatic

Append an item onto the end of a non-full ring buffer.

If the buffer is full, removes its first item, then inserts the new element at the end.

Parameters

rb	Ring buffer to insert into.
element	Value to insert into ring buffer.

Returns

On success, returns -1. If an element was popped, returns the popped value.

Definition at line 173 of file ring_buffer.h.

Referenced by usart_rx_irq().

Here is the call graph for this function:

Here is the caller graph for this function:

rb_remove()

static uint8_t rb_remove ( ring_buffer *  rb )

inlinestatic

Remove and return the first item from a ring buffer.

Parameters

rb	Buffer to remove from, must contain at least one element.

Definition at line 128 of file ring_buffer.h.

Referenced by rb_push_insert(), rb_safe_remove(), F4Light::UART_PPM::read(), usart_getc(), and usart_tx_irq().

Here is the caller graph for this function:

rb_reset()

static void rb_reset ( ring_buffer *  rb )

inlinestatic

Discard all items from a ring buffer.

Parameters

rb	Ring buffer to discard all items from.

Definition at line 186 of file ring_buffer.h.

Referenced by usart_reset_rx(), usart_reset_tx(), usb_ioctl(), and usb_reset_rx().

Here is the caller graph for this function:

rb_safe_insert()

static int rb_safe_insert ( ring_buffer *  rb, uint8_t  element  )

inlinestatic

Attempt to insert an element into a ring buffer.

Parameters

rb	Buffer to insert into.
element	Value to insert into rb. If rb is not full, appends element onto buffer.

Returns

If element was appended, then true; otherwise, false.

Definition at line 154 of file ring_buffer.h.

Referenced by F4Light::UART_PPM::putch(), and usart_rx_irq().

Here is the call graph for this function:

Here is the caller graph for this function:

rb_safe_remove()

static int16_t rb_safe_remove ( ring_buffer *  rb )

inlinestatic

Attempt to remove the first item from a ring buffer.

If the ring buffer is nonempty, removes and returns its first item. If it is empty, does nothing and returns a negative value.

Parameters

rb	Buffer to attempt to remove from.

Definition at line 143 of file ring_buffer.h.

Here is the call graph for this function: