int
DB->set_append_recno(DB *,
int (*db_append_recno_fcn)(DB *dbp, DBT *data, db_recno_t recno));
Description
When using the DB_APPEND option of the DB->put method,
it may be useful to modify the stored data based on the generated key.
If a callback function is specified using the
DB->set_append_recno function, it will be called after the record number
has been selected but before the data has been stored.
The callback function must return 0 on success and errno or
a value outside of the Berkeley DB error name space on failure.
The called function must take three arguments: a reference to the
enclosing database handle, the data DBT to be stored and the
selected record number. The called function may then modify the data
DBT.
The DB->set_append_recno interface may only be used to configure Berkeley DB before
the DB->open interface is called.
The DB->set_append_recno function returns a non-zero error value on failure and 0 on success.