Buffer module

Collaboration diagram for Buffer module:

Data Structures
struct	VOLK_Buffer
	General-purpose data buffer. More...
struct	VOLK_BufferTriple
	Triple of byte buffers. More...

Macros
#define	BTRP_DUMMY   VOLK_btriple_new (BUF_DUMMY, BUF_DUMMY, BUF_DUMMY)
	Dummy buffer triple.
#define	BUF_DUMMY   VOLK_buffer_new (NULL, 0)
	Dummy buffer to be used with VOLK_buffer_init.
#define	NULL_KEY   0
	"NULL" key, a value that is never user-provided.

Enumerations
enum	VOLK_BufferFlag { VOLK_BUF_BORROWED = 1<<0 }
	Buffer flags, stored in buffer structure. More...
enum	VOLK_TriplePos { TRP_POS_S = 0 , TRP_POS_P = 1 , TRP_POS_O = 2 }
	Triple position of s, p, o. More...

Functions
void	VOLK_btriple_done (VOLK_BufferTriple *sspo)
	Free the internal pointers of a buffer triple.
void	VOLK_btriple_free (VOLK_BufferTriple *sspo)
	Free a buffer triple and all its internal pointers.
VOLK_Key	VOLK_btriple_hash (const VOLK_BufferTriple *strp)
	Hash a buffer triple.
VOLK_rc	VOLK_btriple_init (VOLK_BufferTriple *sspo, VOLK_Buffer *s, VOLK_Buffer *p, VOLK_Buffer *o)
	Initialize internal term pointers in a heap-allocated buffer triple.
VOLK_BufferTriple *	VOLK_btriple_new (VOLK_Buffer *s, VOLK_Buffer *p, VOLK_Buffer *o)
	Create a new buffer triple.
VOLK_Buffer *	VOLK_btriple_pos (const VOLK_BufferTriple *btrp, VOLK_TriplePos n)
	Get serialized triple by term position.
char *	VOLK_buffer_as_str (const VOLK_Buffer *buf)
	Format a buffer into anb ASCII string.
int	VOLK_buffer_cmp (const VOLK_Buffer *buf1, const VOLK_Buffer *buf2)
	Compare two buffers.
void	VOLK_buffer_done (VOLK_Buffer *buf)
	Free the content of a buffer.
bool	VOLK_buffer_eq (const VOLK_Buffer *buf1, const VOLK_Buffer *buf2)
	Return whether two buffers are equal.
void	VOLK_buffer_free (VOLK_Buffer *buf)
	Free a buffer.
VOLK_Key	VOLK_buffer_hash (const VOLK_Buffer *buf)
	Hash a buffer.
VOLK_rc	VOLK_buffer_init (VOLK_Buffer *buf, const size_t size, const unsigned char *data)
	Initialize or reuse a buffer handle.
VOLK_Buffer *	VOLK_buffer_new (const unsigned char *data, const size_t size)
	Create a new buffer and optionally populate it with data.
VOLK_Buffer *	VOLK_buffer_new_borrowed (unsigned char *data, const size_t size)
	Create a borrowed buffer (memory view).
void	VOLK_buffer_print (const VOLK_Buffer *buf)
	Print a byte string of a given length in a human-readable format.

Variables
VOLK_Buffer *	VOLK_default_ctx_buf
	Serialized default context.

Detailed Description

Macro Definition Documentation

BTRP_DUMMY

#define BTRP_DUMMY   VOLK_btriple_new (BUF_DUMMY, BUF_DUMMY, BUF_DUMMY)

Dummy buffer triple.

Triple of dummy buffer, with VOLK_Buffer size space allocated, but no contents.

Free with VOLK_btriple_free().

Definition at line 336 of file buffer.h.

BUF_DUMMY

#define BUF_DUMMY   VOLK_buffer_new (NULL, 0)

Dummy buffer to be used with VOLK_buffer_init.

Definition at line 154 of file buffer.h.

NULL_KEY

#define NULL_KEY   0

"NULL" key, a value that is never user-provided.

Used to mark special values (e.g. deleted records).

Definition at line 15 of file buffer.h.

Enumeration Type Documentation

VOLK_BufferFlag

enum VOLK_BufferFlag

Buffer flags, stored in buffer structure.

Enumerator
VOLK_BUF_BORROWED	Borrowed buffer. This indicates that the memory block pointed to by the buffer is owned by another function, and instructs VOLK_buffer_free() to only free the buffer handle, but not the underlying data.

Definition at line 27 of file buffer.h.

VOLK_TriplePos

enum VOLK_TriplePos

Triple position of s, p, o.

Enumerator
TRP_POS_S
TRP_POS_P
TRP_POS_O

Definition at line 19 of file buffer.h.

Function Documentation

VOLK_btriple_done()

void VOLK_btriple_done

(

VOLK_BufferTriple *

sspo

)

Free the internal pointers of a buffer triple.

Parameters

[in]

sspo

Buffer triple to be freed.

Definition at line 136 of file buffer.c.

VOLK_btriple_free()

void VOLK_btriple_free

(

VOLK_BufferTriple *

sspo

)

Free a buffer triple and all its internal pointers.

Important

If the buffer pointers are not to be freed (e.g. they are owned by a back end), use a simple free(sspo) instead of this.

Parameters

[in]

sspo

Buffer triple to be freed.

Definition at line 147 of file buffer.c.

VOLK_btriple_hash()

VOLK_Key VOLK_btriple_hash ( const VOLK_BufferTriple * strp )

inline

Hash a buffer triple.

Todo

This doesn't handle blank nodes correctly. RDF_Canon should be ported to this library.

Parameters

[in]

strp

Serialized triple to hash.

Returns

Hash value.

Definition at line 317 of file buffer.h.

VOLK_btriple_init()

VOLK_rc VOLK_btriple_init	(	VOLK_BufferTriple *	sspo,
		VOLK_Buffer *	s,
		VOLK_Buffer *	p,
		VOLK_Buffer *	o )

Initialize internal term pointers in a heap-allocated buffer triple.

Important

The triple must be freed with VOLK_btriple_free().

Parameters

[in]	sspo	Serialized triple pointer to initialize.
[in]	s	Subject as a serialized buffer.
[in]	p	Predicate as a serialized buffer.
[in]	o	Object as a serialized buffer.

Returns

VOLK_OK on success.

Definition at line 124 of file buffer.c.

VOLK_btriple_new()

VOLK_BufferTriple * VOLK_btriple_new	(	VOLK_Buffer *	s,
		VOLK_Buffer *	p,
		VOLK_Buffer *	o )

Create a new buffer triple.

Important

The triple must be freed with VOLK_btriple_free().

Parameters

[in]	s	Subject as a serialized buffer.
[in]	p	Predicate as a serialized buffer.
[in]	o	Object as a serialized buffer.

Returns

New triple.

Definition at line 109 of file buffer.c.

VOLK_btriple_pos()

VOLK_Buffer * VOLK_btriple_pos ( const VOLK_BufferTriple * btrp, VOLK_TriplePos n )

inline

Get serialized triple by term position.

Useful for looping over all terms.

Parameters

[in]	btrp	Serialized triple pointer.
[in]	n	A number between 0÷2.

Returns

Corresponding serialized term or NULL if n is out of range.

Definition at line 297 of file buffer.h.

VOLK_buffer_as_str()

char * VOLK_buffer_as_str

(

const VOLK_Buffer *

buf

)

Format a buffer into anb ASCII string.

The string has non-printable characters escaped as "\xNN".

Parameters

[in]

buf

Buffer to convert.

Returns

Formatted string. It must be freed with free().

Definition at line 58 of file buffer.c.

VOLK_buffer_cmp()

int VOLK_buffer_cmp ( const VOLK_Buffer * buf1, const VOLK_Buffer * buf2 )

inline

Compare two buffers.

The return value is the same as memcmp.

Definition at line 206 of file buffer.h.

VOLK_buffer_done()

void VOLK_buffer_done

(

VOLK_Buffer *

buf

)

Free the content of a buffer.

Note

This function is safe to use on borrowed buffers.

Definition at line 92 of file buffer.c.

VOLK_buffer_eq()

bool VOLK_buffer_eq ( const VOLK_Buffer * buf1, const VOLK_Buffer * buf2 )

inline

Return whether two buffers are equal.

This may be faster than VOLK_buffer_cmp() because it does a size comparison first.

Definition at line 219 of file buffer.h.

VOLK_buffer_free()

void VOLK_buffer_free

(

VOLK_Buffer *

buf

)

Free a buffer.

Note

This function is safe to use on borrowed buffers. In such case, only the VOLK_Buffer structure is freed, but not the underlying data.

Definition at line 97 of file buffer.c.

VOLK_buffer_hash()

VOLK_Key VOLK_buffer_hash ( const VOLK_Buffer * buf )

inline

Hash a buffer.

Definition at line 175 of file buffer.h.

VOLK_buffer_init()

VOLK_rc VOLK_buffer_init	(	VOLK_Buffer *	buf,
		const size_t	size,
		const unsigned char *	data )

Initialize or reuse a buffer handle.

The handle must have been created with VOLK_buffer_new*().

The data block is resized without being freed first. The handle must be eventually freed with VOLK_buffer_done() after use.

Parameters

[in]	buf	A buffer handle obtained with VOLK_buffer_new or by manual allocation.
[in]	size	New size.
[in]	data	If not NULL, data to replace the existing ones. The size of the data to be copied is determined by the size parameter. If NULL, the existing data are preserved as with a normal realloc().

Definition at line 18 of file buffer.c.

VOLK_buffer_new()

VOLK_Buffer * VOLK_buffer_new ( const unsigned char * data, const size_t size )

inline

Create a new buffer and optionally populate it with data.

To change the buffer size and/or data later call VOLK_buffer_init.

To copy a buffer just do buf2 = VOLK_buffer_new (buf1->addr, buf1->size);

Parameters

[in]	size	Length of the data.
[in]	data	Optional data to initially populate the object with. If NULL, the buffer data are garbage.

Returns

VOLK_Buffer handle. It must be freed with VOLK_buffer_free. NULL on error.

Definition at line 111 of file buffer.h.

VOLK_buffer_new_borrowed()

VOLK_Buffer * VOLK_buffer_new_borrowed ( unsigned char * data, const size_t size )

inline

Create a borrowed buffer (memory view).

A borrowed buffer does not own the memory block pointed to and should not be freed. It can be identified by the VOLK_BUF_BORROWED flag.

Parameters

[in]	data	Address of data handled by the buffer.
[in]	size	Length of the data.

Returns

VOLK_Buffer handle. It must be freed with VOLK_buffer_free, which will correctly leave the underlying data alone. NULL on error.

Definition at line 139 of file buffer.h.

VOLK_buffer_print()

void VOLK_buffer_print

(

const VOLK_Buffer *

buf

)

Print a byte string of a given length in a human-readable format.

The string is printed in Python style: printable characters are output literally, and non-printable ones as hex sequences.

Definition at line 43 of file buffer.c.

Variable Documentation

VOLK_default_ctx_buf

VOLK_Buffer* VOLK_default_ctx_buf

extern

Serialized default context.

Definition at line 5 of file buffer.c.