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Berkeley DB: DB->set_malloc

DB->set_malloc

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#include <db.h>

int DB->set_malloc(DB *db, void *(*db_malloc)(size_t size));

Description

Set the allocation function used by the DB methods to allocate memory in which to return key/data items to the application.

The DB_DBT_MALLOC flag, when specified in the DBT object, will cause the DB methods to allocate and re-allocate memory which then becomes the responsibility of the calling application. See DBT for more information.

On systems where there may be multiple library versions of malloc (notably Windows NT), specifying the DB_DBT_MALLOC flag will fail because the DB library will allocate memory from a different heap than the application will use to free it. To avoid this problem, the DB->set_malloc function can be used to pass Berkeley DB a reference to the application's allocation routine, in which case it will be used to allocate the memory returned when the DB_DBT_MALLOC flag is set.

The function specified must match the calling conventions of the ANSI C X3.159-1989 (ANSI C) library routine of the same name.

The DB->set_malloc interface may only be used to configure Berkeley DB before the DB->open interface is called.

The DB->set_malloc function returns a non-zero error value on failure and 0 on success.

Errors

EINVAL
An invalid flag value or parameter was specified.

See Also

db_create, DB->close, DB->cursor, DB->del, DB->err, DB->fd, DB->get, DB->get_byteswapped, DB->get_type, DB->join, DB->key_range, DB->open, DB->put, DB->remove, DB->set_bt_compare, DB->set_bt_minkey, DB->set_bt_prefix, DB->set_cachesize, DB->set_dup_compare, DB->set_errcall, DB->set_errfile, DB->set_errpfx, DB->set_flags, DB->set_h_ffactor, DB->set_h_hash, DB->set_h_nelem, DB->set_lorder, DB->set_malloc, DB->set_pagesize, DB->set_paniccall, DB->set_q_extentsize, DB->set_realloc, DB->set_re_delim, DB->set_re_len, DB->set_re_pad, DB->set_re_source, DB->stat, DB->sync, DB->upgrade and DB->verify.

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