1BSON_OID(3)                         libbson                        BSON_OID(3)
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NAME

6       bson_oid - ObjectIDs
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8       Libbson  provides a simple way to generate ObjectIDs. It can be used in
9       a single-threaded or multi-threaded manner depending on  your  require‐
10       ments.
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12       The  bson_oid_t  structure  represents  an ObjectID in MongoDB. It is a
13       96-bit identifier.
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COMPOSITION

16       • 4 bytes : The UNIX timestamp in big-endian format.
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18       • 5 bytes : A random number.
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20       • 3 bytes : A 24-bit monotonic  counter  incrementing  from  rand()  in
21         big-endian.
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SORTING OBJECTIDS

24       The  typical way to sort in C is using qsort(). Therefore, Libbson pro‐
25       vides a qsort() compatible callback function named  bson_oid_compare().
26       It  returns less than 1, greater than 1, or 0 depending on the equality
27       of two bson_oid_t structures.
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COMPARING OBJECT IDS

30       If you simply want to compare two bson_oid_t structures  for  equality,
31       use bson_oid_equal().
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GENERATING

34       To generate a bson_oid_t, you may use the following.
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36          bson_oid_t oid;
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38          bson_oid_init (&oid, NULL);
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PARSING OBJECTID STRINGS

41       You  can  also parse a string containing a bson_oid_t. The input string
42       MUST be 24 characters or more in length.
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44          bson_oid_t oid;
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46          bson_oid_init_from_string (&oid, "123456789012345678901234");
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48          bson_oid_t oid;
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50          bson_oid_init_from_string_unsafe (&oid, "123456789012345678901234");
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HASHING OBJECTIDS

53       If you need to store items in a hashtable, you  may  want  to  use  the
54       bson_oid_t  as  the key. Libbson provides a hash function for just this
55       purpose. It is based on DJB hash.
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57          unsigned hash;
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59          hash = bson_oid_hash (oid);
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FETCHING OBJECTID CREATION TIME

62       You can easily fetch the time that a  bson_oid_t  was  generated  using
63       bson_oid_get_time_t().
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65          time_t t;
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67          t = bson_oid_get_time_t (oid);
68          printf ("The OID was generated at %u\n", (unsigned) t);
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AUTHOR

71       MongoDB, Inc
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74       2017-present, MongoDB, Inc
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791.20.0                           Nov 18, 2021                      BSON_OID(3)
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