QBMAP.H(3) libqb Programmer's Manual QBMAP.H(3)

qbmap.h - This provides a map interface to a Patricia trie, hashtable or skiplist.

#include <qb/qbmap.h>


The hashtable is NOT ordered, but ptrie and skiplist are.


Below is a simple example of how to iterate over a map.

const char *p;
void *data;
qb_map_iter_t *it = qb_map_iter_create(m);
for (p = qb_map_iter_next(it, &data); p; p = qb_map_iter_next(it, &data)) {
    printf("%s > %s0, p, (char*) data);

Deletion of items within the iterator is supported. But note do not free the item memory in the iterator. If you need to free the data items then register for a notifier and free the memory there. This is required as the items are reference counted.

qb_map_notify_add(m, NULL, my_map_free_handler,
             QB_MAP_NOTIFY_FREE, NULL);


These allow you to get callbacks when values are inserted/removed or replaced.

Prefix matching

The ptrie supports prefixes in the iterator:

it = qb_map_pref_iter_create(m, "aa");
while ((p = qb_map_iter_next(it, &data)) != NULL) {
    printf("%s > %s0, p, (char*)data);

The ptrie also supports prefixes in notifications: (remember to pass QB_MAP_NOTIFY_RECURSIVE into the notify_add.

qb_map_notify_add(m, "root", my_map_notification,

hashtable only supports deletion and replacement notificatins. There is also a special global callback for freeing deleted and replaced values (QB_MAP_NOTIFY_FREE).

qb_trie_dump(3), qb_map_iter_create(3), qb_skiplist_create(3), qb_map_notify_del(3), qb_map_put(3), qb_map_count_get(3), qb_map_foreach(3), qb_map_pref_iter_create(3), qb_map_iter_next(3), qb_map_get(3), qb_map_destroy(3), qb_hashtable_create(3), qb_map_iter_free(3), qb_map_notify_add(3), qb_trie_create(3), qb_map_notify_del_2(3), qb_map_rm(3)

Copyright (C) 2010-2020 Red Hat, Inc.
2021-03-03 LIBQB