Jack Utils FIFO Buffer API

Data Structures
struct	ju_buff_s
	FIFO Buffer internal structure. More...

Typedefs
typedef struct ju_buff_s	ju_buff_t
	typedef wrapper around buffer structure

Functions
JBU_API void()	ju_buff_init (ju_buff_t *b, size_t s)
	Initializes buffer structure. More...
JBU_API void()	ju_buff_uninit (ju_buff_t *b)
	Deinitializes buffer structure. More...
JBU_API void()	ju_buff_resize (ju_buff_t *b, size_t s)
	Resizes buffer structure. More...
JBU_API void()	ju_buff_check_size (ju_buff_t *b, size_t s)
	Check size of buffer with requested, and resizes if there is not enough spce. More...
JBU_API void	ju_buff_except (ju_buff_t *b, int(*cb)(ju_buff_t *, ju_ssize_t))
	Underflow/owerflow exception handling. More...
JBU_API size_t()	ju_buff_size (ju_buff_t *b)
	Returns buffer summary size (used and unused). More...
JBU_API size_t()	ju_buff_used (ju_buff_t *b)
	Returns size of buffer busy part. More...
JBU_API size_t()	ju_buff_space (ju_buff_t *b)
	Returns size of buffer empity part. More...
JBU_API size_t()	ju_buff_append (ju_buff_t *b, const void *src, size_t size)
	Adds data from array to te end of the buffer. More...
JBU_API size_t()	ju_buff_fill (ju_buff_t *b, const void *src, size_t size, size_t n)
	Adds data from src array copied N times to the end of the buffer. More...
JBU_API size_t()	ju_buff_remove (ju_buff_t *, void *dst, size_t size)
	Removes data from start of buffer to the dst array. More...
JBU_API void()	ju_buff_move (ju_buff_t *, ju_ssize_t v)
	Moves buffer data forwards or backwards... More...
JBU_API size_t()	ju_buff_read (ju_buff_t *, int fd, size_t)
	Similar to ju_buff_append(), but reads values from the file by descriptor.
JBU_API size_t()	ju_buff_write (ju_buff_t *, int fd, size_t)
	Similar to ju_buff_remove(), but writes values to the the file by descriptor.
JBU_API void *()	ju_buff_data (ju_buff_t *b)
	Returns buffer data from the beginning. More...
JBU_API void()	ju_buff_lock (ju_buff_t *b)
	Locks buffer. More...
JBU_API void()	ju_buff_unlock (ju_buff_t *b)
	Unlocks buffer. More...

Detailed Description

Function Documentation

ju_buff_append()

JBU_API size_t() ju_buff_append	(	ju_buff_t *	b,
		const void *	src,
		size_t	size
	)

Adds data from array to te end of the buffer.

Parameters

b	buffer.
src	source array of bytes.
size	size of the source array.

Returns

count of appended bytes

References ju_buff_space().

ju_buff_check_size()

JBU_API void() ju_buff_check_size	(	ju_buff_t *	b,
		size_t	s
	)

Check size of buffer with requested, and resizes if there is not enough spce.

Parameters

b	pointer on buffer structure.
s	requested size of the buffer.

ju_buff_data()

JBU_API void *() ju_buff_data

(

ju_buff_t *

b

)

Returns buffer data from the beginning.

Parameters

b

buffer

Returns

pointer on the data at the beginning of the buffer

ju_buff_except()

JBU_API void ju_buff_except	(	ju_buff_t *	b,
		int(*)(ju_buff_t *, ju_ssize_t)	cb
	)

Underflow/owerflow exception handling.

Sets cb callback to be runned when exeption happens with buffer underflow(-) or owerflow(+) value. Callback may MOVE buffer data backward to give space for new data in case of owerflow(default), or do nothing. In case of underflow, callback may add zeros to buffer, or do nothing(default).

Or even callback may print error message, and do some stuff of course :) Callback underflow/overflow value will NEVER BE MORE THAN SIZE OF BUFFER!

if you did something, it's a good sign to return 0, else return nonzero value from callback;

Parameters

b	buffer
cb	new exception handler callback

ju_buff_fill()

JBU_API size_t() ju_buff_fill	(	ju_buff_t *	b,
		const void *	src,
		size_t	size,
		size_t	n
	)

Adds data from src array copied N times to the end of the buffer.

Parameters

b	buffer.
src	source array of bytes.
size	size of the source array.
n	how much array duplicates?

Returns

count of appended bytes

References ju_buff_space().

ju_buff_init()

JBU_API void() ju_buff_init	(	ju_buff_t *	b,
		size_t	s
	)

Initializes buffer structure.

Parameters

b	pointer on buffer structure.
s	size of the buffer.

ju_buff_lock()

JBU_API void() ju_buff_lock

(

ju_buff_t *

b

)

Locks buffer.

Parameters

b

buffer

If buffer is already locked, this function waits until it unlocks, lock it again and returns. This operation is atomary and threadsafe.

Don't forget to unlock buffer when you're done reading/writing and other buffer operations. Locking already locked buffer in the same thread causes to the DEADLOCK.

ju_buff_move()

JBU_API void() ju_buff_move	(	ju_buff_t *	b,
		ju_ssize_t	v
	)

Moves buffer data forwards or backwards...

Parameters

b	buffer.
v	move steps with sign (+ forward) (-backward)

ju_buff_remove()

JBU_API size_t() ju_buff_remove	(	ju_buff_t *	b,
		void *	dst,
		size_t	size
	)

Removes data from start of buffer to the dst array.

Parameters

b	buffer.
dst	destination array of bytes.
size	how many elements to put into the array.

Returns

count of removed bytes

References ju_buff_move().

ju_buff_resize()

JBU_API void() ju_buff_resize	(	ju_buff_t *	b,
		size_t	s
	)

Resizes buffer structure.

Buffer must be initialized before!

Parameters

b	pointer on buffer structure.
s	size of the buffer.

ju_buff_size()

JBU_API size_t() ju_buff_size

(

ju_buff_t *

b

)

Returns buffer summary size (used and unused).

Parameters

b

buffer

Returns

buffer size

ju_buff_space()

JBU_API size_t() ju_buff_space

(

ju_buff_t *

b

)

Returns size of buffer empity part.

Parameters

b

buffer

Returns

buffer free space size

ju_buff_uninit()

JBU_API void() ju_buff_uninit

(

ju_buff_t *

b

)

Deinitializes buffer structure.

Parameters

b	pointer on buffer structure.

ju_buff_unlock()

JBU_API void() ju_buff_unlock

(

ju_buff_t *

b

)

Unlocks buffer.

Parameters

b

buffer

ju_buff_used()

JBU_API size_t() ju_buff_used

(

ju_buff_t *

b

)

Returns size of buffer busy part.

Parameters

b

buffer

Returns

buffer used part size