DOKK / manpages / debian 12 / libbson-doc / bson_oid_t.3.en
BSON_OID_T(3) libbson BSON_OID_T(3)

bson_oid_t - bson_oid_t

BSON ObjectID Abstraction

#include <bson/bson.h>
typedef struct {

uint8_t bytes[12]; } bson_oid_t;


The bson_oid_t structure contains the 12-byte ObjectId notation defined by the BSON ObjectID specification.

ObjectId is a 12-byte BSON type, constructed using:

  • a 4-byte value representing the seconds since the Unix epoch (in Big Endian).
  • a 5-byte random value.
  • a 3-byte counter (Big Endian), starting with a random value.

You can convert an Object ID to a string using bson_oid_to_string() and back with bson_oid_init_from_string().

A bson_oid_t can be used in hashtables using the function bson_oid_hash() and bson_oid_equal().

A bson_oid_t can be compared to another using bson_oid_compare() for qsort() style comparing and bson_oid_equal() for direct equality.

You can validate that a string containing a hex-encoded ObjectID is valid using the function bson_oid_is_valid().

#include <bson/bson.h>
#include <stdio.h>
int
main (int argc, char *argv[])
{

bson_oid_t oid;
char str[25];
bson_oid_init (&oid, NULL);
bson_oid_to_string (&oid, str);
printf ("%s\n", str);
if (bson_oid_is_valid (str, sizeof str)) {
bson_oid_init_from_string (&oid, str);
}
printf ("The UNIX time was: %u\n", (unsigned) bson_oid_get_time_t (&oid));
return 0; }


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October 20, 2022 1.23.1