Universally Unique IDentifiers (UUIDs)

Routines to generate and work with universally unique identifiers. More...

Collaboration diagram for Universally Unique IDentifiers (UUIDs):

Files
file	uuid.h

Macros
#define	STATIC_ARRAY(x)   (x)

Functions
int	bu_uuid_create (uint8_t uuid[STATIC_ARRAY(16)], size_t nbytes, const uint8_t *bytes, const uint8_t namespace_uuid[STATIC_ARRAY(16)])
int	bu_uuid_compare (const void *uuid_left, const void *uuid_right)
int	bu_uuid_encode (const uint8_t uuid[STATIC_ARRAY(16)], uint8_t cp[STATIC_ARRAY(37)])
int	bu_uuid_decode (const char *cp, uint8_t uuid[STATIC_ARRAY(16)])

Detailed Description

Routines to generate and work with universally unique identifiers.

Macro Definition Documentation

STATIC_ARRAY

#define STATIC_ARRAY

(

x

)

(x)

Definition at line 44 of file uuid.h.

Function Documentation

bu_uuid_create()

int bu_uuid_create	(	uint8_t	uuid[STATIC_ARRAY(16)],
		size_t	nbytes,
		const uint8_t *	bytes,
		const uint8_t	namespace_uuid[STATIC_ARRAY(16)]
	)

Create a UUID (a 128-bit identifier) that conforms with RFC4122, version 4 or 5, in big endian network order. Version 4 UUIDs are suitable for a random object identifier (with 122 bits of random entropy). Providing a byte array and namespace will create a (SHA1-based) version 5 UUID suitable for repeatable identifier hashing.

bu_uuid_compare()

int bu_uuid_compare	(	const void *	uuid_left,
		const void *	uuid_right
	)

This is a convenience UUID comparison routine compatible with stdlib sorting functions (e.g., bu_sort()). The function expects both left and right UUIDs to be uint8_t[16] arrays.

Returns:

<0 if a < b 0 if a == b >0 if a > b

bu_uuid_encode()

int bu_uuid_encode	(	const uint8_t	uuid[STATIC_ARRAY(16)],
		uint8_t	cp[STATIC_ARRAY(37)]
	)

Converts a UUID into a string representation of the following style: "00112233-4455-6677-8899-AABBCCDDEEFF"

The caller must provide a 36-byte + 1-byte (for nul) array to write the result and will need to manually convert this into a string or add braces as desired by the calling application. For example:

uint8_t uuid[16] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff};
char uuidstr[39] = {0};
(void)bu_uuid_encode(uuid, (uint8_t *)(uuidstr+1));
uuidstr[0] = '{';
uuidstr[sizeof(uuidstr)-2] = '}';
uuidstr[sizeof(uuidstr)-1] = '\0';
printf("UUID is %s\n", uuidstr);

bu_uuid_decode()

int bu_uuid_decode	(	const char *	cp,
		uint8_t	uuid[STATIC_ARRAY(16)]
	)

Converts a string (e.g., "{12B01234-f543-39d9-BFE0-0098765432F1}") into a UUID. The input string must be nul-terminated. Brackets are optional and are ignored. Hyphens can appear anywhere or be missing. The hex digits can be any mixture of upper or lower case.