tdb_traverse3

Usage

#include <tdb.h>

int tdb_traverse(TDB_CONTEXT *tdb, 
        int (*fn)(TDB_CONTEXT *,TDB_DATA,TDB_DATA,void *),
        void *state);

Overview

tdb_traverse is the only sure way to visit all the items within a given database, tdb Because this function has intimate knowledge of the internals of the database, it is able to cope with writers touching the database at the same time it is trying to traverse it.

If fn is supplied it will be called with the state parameter for each element in the database, as the forth argument. The First argument is the database tdb the second is the key and the third is the data. If this function call returns anything but 0, the traversal will stop. Unlike in tdb_fetch() the programmer is not required to free either the pointer from either the key or data parameters that are passed into the function. The fn function should have the prototype:

int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *);

Calling tdb_traverse with a NULL fn parameter is the appropriate way to count the number of elements in the database.

Return value

The return value is the number of elements traversed or -1 if there was an error.