Circular Buffer

Files
file	cbuf.h
file	xbee_cbuf.c

Data Structures
struct	xbee_cbuf_t

Typedefs
typedef XBEE_BEGIN_DECLS struct xbee_cbuf_t	xbee_cbuf_t

Functions
void	xbee_cbuf_flush (xbee_cbuf_t FAR *cbuf)
	Flush the contents of the circular buffer. More...
uint_fast8_t	xbee_cbuf_free (xbee_cbuf_t FAR *cbuf)
	Returns the number of additional bytes that can be stored in the circular buffer. More...
uint_fast8_t	xbee_cbuf_get (xbee_cbuf_t *cbuf, void FAR *buffer, uint_fast8_t length)
	Read (and remove) multiple bytes from circular buffer. More...
int	xbee_cbuf_getch (xbee_cbuf_t FAR *cbuf)
	Remove and return the first byte of the circular buffer. More...
int	xbee_cbuf_init (xbee_cbuf_t FAR *cbuf, uint_fast8_t datasize)
	Initialize the fields of the circular buffer. More...
uint_fast8_t	xbee_cbuf_put (xbee_cbuf_t FAR *cbuf, const void FAR *buffer, uint_fast8_t length)
	Append multiple bytes to the end of a circular buffer. More...
int	xbee_cbuf_putch (xbee_cbuf_t FAR *cbuf, uint_fast8_t ch)
	Append a single byte to the circular buffer (if not full). More...
uint_fast8_t	xbee_cbuf_used (xbee_cbuf_t FAR *cbuf)
	Returns the number of bytes stored in the circular buffer. More...

Variables
uint8_t	data [1]
uint8_t	head
uint8_t	lock
uint8_t	mask
uint8_t	tail

Detailed Description

Typedef Documentation

typedef XBEE_BEGIN_DECLS struct xbee_cbuf_t xbee_cbuf_t

Circular buffer used by transparent serial cluster handler. Buffer is empty when head == tail and full when head == (tail - 1).

Function Documentation

void xbee_cbuf_flush

(

xbee_cbuf_t FAR *

cbuf

)

Flush the contents of the circular buffer.

Parameters

[in,out]

cbuf

Pointer to circular buffer.

uint_fast8_t xbee_cbuf_free

(

xbee_cbuf_t FAR *

cbuf

)

Returns the number of additional bytes that can be stored in the circular buffer.

Parameters

[in]

cbuf

Pointer to circular buffer.

Return values

0-255

Number of unused bytes in the circular buffer.

See also

xbee_cbuf_length, xbee_cbuf_free

uint_fast8_t xbee_cbuf_get	(	xbee_cbuf_t *	cbuf,
		void FAR *	buffer,
		uint_fast8_t	length
	)

Read (and remove) multiple bytes from circular buffer.

Parameters

[in,out]	cbuf	circular buffer
[out]	buffer	destination to copy data from circular buffer
[in]	length	number of bytes to copy

Return values

0-255

number of bytes copied (may be less than length if buffer is empty)

int xbee_cbuf_getch

(

xbee_cbuf_t FAR *

cbuf

)

Remove and return the first byte of the circular buffer.

Parameters

[in]

cbuf

Pointer to circular buffer.

Return values

-1	buffer is empty
0-255	byte removed from the head of the buffer

See also

xbee_cbuf_putch, xbee_cbuf_get, xbee_cbuf_put

int xbee_cbuf_init	(	xbee_cbuf_t FAR *	cbuf,
		uint_fast8_t	datasize
	)

Initialize the fields of the circular buffer.

Note

You must initialize the xbee_cbuf_t structure before using it with any other xbee_cbuf_xxx() functions. If you have ISRs pushing data into the buffer, don't enable them until AFTER you've called xbee_cbuf_init.

Parameters

[in,out]	cbuf	Address of buffer to use for the circular buffer. This buffer must be (datasize + CBUF_OVEREAD) bytes long to hold the locks, head, tail, size and buffered bytes.
[in]	datasize	Maximum number of bytes to store in the circular buffer. This size must be at least 3, no more than 255, and a power of 2 minus 1 (2^n - 1).

Return values

0	success
-EINVAL	invalid parameter

uint_fast8_t xbee_cbuf_put	(	xbee_cbuf_t FAR *	cbuf,
		const void FAR *	buffer,
		uint_fast8_t	length
	)

Append multiple bytes to the end of a circular buffer.

Parameters

[in,out]	cbuf	circular buffer
[in]	buffer	data to copy into circular buffer
[in]	length	number of bytes to copy

Return values

0-255

number of bytes copied (may be less than length if buffer is full)

int xbee_cbuf_putch	(	xbee_cbuf_t FAR *	cbuf,
		uint_fast8_t	ch
	)

Append a single byte to the circular buffer (if not full).

Parameters

[in,out]	cbuf	Pointer to circular buffer.
[in]	ch	Byte to append.

Return values

0	buffer is full
1	the byte was appended

See also

xbee_cbuf_getch, xbee_cbuf_get, xbee_cbuf_put

uint_fast8_t xbee_cbuf_used

(

xbee_cbuf_t FAR *

cbuf

)

Returns the number of bytes stored in the circular buffer.

Parameters

[in]

cbuf

Pointer to circular buffer.

Return values

0-255

Number of bytes stored in the circular buffer.

See also

xbee_cbuf_length, xbee_cbuf_free

Variable Documentation

uint8_t data[1]

uint8_t head

uint8_t lock

uint8_t mask

uint8_t tail