bson_oid_t

BSON ObjectID Abstraction

Synopsis

#include <bson/bson.h>

typedef struct {
   uint8_t bytes[12];
} bson_oid_t;

Description

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.

String Conversion

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

Hashing

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

Comparing

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

Validating

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

Functions

• bson_oid_compare()
• bson_oid_copy()
• bson_oid_equal()
• bson_oid_get_time_t()
• bson_oid_hash()
• bson_oid_init()
• bson_oid_init_from_data()
• bson_oid_init_from_string()
• bson_oid_init_sequence()
• bson_oid_is_valid()
• bson_oid_to_string()

Example

#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;
}