size_t
ipset_node_reachable_count(const struct ipset_node_cache *cache,
ipset_node_id node)
{
/* Create a set to track when we've visited a given node. */
struct cork_hash_table *visited = cork_pointer_hash_table_new(0, 0);
/* And a queue of nodes to check. */
cork_array(ipset_node_id) queue;
cork_array_init(&queue);
if (ipset_node_get_type(node) == IPSET_NONTERMINAL_NODE) {
DEBUG("Adding node %u to queue", node);
cork_array_append(&queue, node);
}
/* And somewhere to store the result. */
size_t node_count = 0;
/* Check each node in turn. */
while (!cork_array_is_empty(&queue)) {
ipset_node_id curr = cork_array_at(&queue, --queue.size);
/* We don't have to do anything if this node is already in the
* visited set. */
if (cork_hash_table_get(visited, (void *) (uintptr_t) curr) == NULL) {
DEBUG("Visiting node %u for the first time", curr);
/* Add the node to the visited set. */
cork_hash_table_put
(visited, (void *) (uintptr_t) curr,
(void *) (uintptr_t) true, NULL, NULL, NULL);
/* Increase the node count. */
node_count++;
/* And add the node's nonterminal children to the visit
* queue. */
struct ipset_node *node =
ipset_node_cache_get_nonterminal(cache, curr);
if (ipset_node_get_type(node->low) == IPSET_NONTERMINAL_NODE) {
DEBUG("Adding node %u to queue", node->low);
cork_array_append(&queue, node->low);
}
if (ipset_node_get_type(node->high) == IPSET_NONTERMINAL_NODE) {
DEBUG("Adding node %u to queue", node->high);
cork_array_append(&queue, node->high);
}
}
}
/* Return the result, freeing everything before we go. */
cork_hash_table_free(visited);
cork_array_done(&queue);
return node_count;
}
static int
save_bdd(struct save_data *save_data,
struct ipset_node_cache *cache, ipset_node_id root)
{
/* First, output the file header. */
DEBUG("Writing file header");
rii_check(save_data->write_header(save_data, cache, root));
/* The serialized node IDs are different than the in-memory node
* IDs. This means that, for our nonterminal nodes, we need a
* mapping from internal node ID to serialized node ID. */
DEBUG("Creating file caches");
save_data->serialized_ids = cork_pointer_hash_table_new(0, 0);
save_data->next_serialized_id = -1;
/* Trace down through the BDD tree, outputting each terminal and
* nonterminal node as they're encountered. */
DEBUG("Writing nodes");
serialized_id last_serialized_id;
ei_check(save_visit_node(save_data, root, &last_serialized_id));
/* Finally, output the file footer and cleanup. */
DEBUG("Writing file footer");
ei_check(save_data->write_footer(save_data, cache, root));
DEBUG("Freeing file caches");
cork_hash_table_free(save_data->serialized_ids);
return 0;
error:
/* If there's an error, clean up the objects that we've created
* before returning. */
cork_hash_table_free(save_data->serialized_ids);
return -1;
}
