Map

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

Ordering

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

Iterating

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 > %s\n", p, (char*) data);
 }
 qb_map_iter_free(it);

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);

Notifications

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

Note:

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

See also:

qb_map_notify_add() qb_map_notify_del_2()

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 > %s\n", p, (char*)data);
 }
 qb_map_iter_free(it);

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,
                    (QB_MAP_NOTIFY_INSERTED|
                     QB_MAP_NOTIFY_DELETED|
                     QB_MAP_NOTIFY_REPLACED|
                     QB_MAP_NOTIFY_RECURSIVE),
                    NULL);

See also:

qbmap.h