struct loc_stringpool* pool;
};
+#define MAX_STACK_DEPTH 256
+
+struct loc_node_stack {
+ off_t offset;
+ int i; // Is this node 0 or 1?
+ int depth;
+};
+
struct loc_database_enumerator {
struct loc_ctx* ctx;
struct loc_database* db;
// Index of the AS we are looking at
unsigned int as_index;
+
+ // Network state
+ struct in6_addr network_address;
+ struct loc_node_stack network_stack[MAX_STACK_DEPTH];
+ int network_stack_depth;
+ unsigned int* networks_visited;
};
static int loc_database_read_magic(struct loc_database* db, FILE* f) {
e->db = loc_database_ref(db);
e->refcount = 1;
+ // Initialise graph search
+ //e->network_stack[++e->network_stack_depth] = 0;
+ e->network_stack_depth = 1;
+ e->networks_visited = calloc(db->network_nodes_count, sizeof(*e->networks_visited));
+
DEBUG(e->ctx, "Database enumerator object allocated at %p\n", e);
*enumerator = e;
// We have searched through all of them
return NULL;
}
+
+static int loc_database_enumerator_stack_push_node(
+ struct loc_database_enumerator* e, off_t offset, int i, int depth) {
+ // Do not add empty nodes
+ if (!offset)
+ return 0;
+
+ // Check if there is any space left on the stack
+ if (e->network_stack_depth >= MAX_STACK_DEPTH) {
+ ERROR(e->ctx, "Maximum stack size reached: %d\n", e->network_stack_depth);
+ return -1;
+ }
+
+ // Increase stack size
+ int s = ++e->network_stack_depth;
+
+ DEBUG(e->ctx, "Added node %jd to stack (%d)\n", offset, depth);
+
+ e->network_stack[s].offset = offset;
+ e->network_stack[s].i = i;
+ e->network_stack[s].depth = depth;
+
+ return 0;
+}
+
+static int loc_database_enumerator_network_depth_first_search(
+ struct loc_database_enumerator* e, struct loc_network** network) {
+ // Reset network
+ *network = NULL;
+ int r;
+
+ DEBUG(e->ctx, "Called with a stack of %u nodes\n", e->network_stack_depth);
+
+ // Perform DFS
+ while (e->network_stack_depth > 0) {
+ DEBUG(e->ctx, "Stack depth: %u\n", e->network_stack_depth);
+
+ // Get object from top of the stack
+ struct loc_node_stack* node = &e->network_stack[e->network_stack_depth];
+
+ // Remove the node from the stack if we have already visited it
+ if (e->networks_visited[node->offset]) {
+ e->network_stack_depth--;
+ continue;
+ }
+
+ in6_addr_set_bit(&e->network_address,
+ (node->depth > 0) ? node->depth - 1 : 0, node->i);
+
+ //for (unsigned int i = stack->depth + 1; i < 128; i++)
+ // in6_addr_set_bit(&e->network_address, i, 0);
+
+ DEBUG(e->ctx, "Looking at node %jd\n", node->offset);
+ e->networks_visited[node->offset]++;
+
+ // Pop node from top of the stack
+ struct loc_database_network_node_v0* n =
+ e->db->network_nodes_v0 + node->offset;
+
+ // Add edges to stack
+ r = loc_database_enumerator_stack_push_node(e,
+ be32toh(n->one), 1, node->depth + 1);
+
+ if (r)
+ return r;
+
+ r = loc_database_enumerator_stack_push_node(e,
+ be32toh(n->zero), 0, node->depth + 1);
+
+ if (r)
+ return r;
+
+ // Check if this node is a leaf and has a network object
+ if (__loc_database_node_is_leaf(n)) {
+ off_t network_index = be32toh(n->network);
+
+ DEBUG(e->ctx, "Node has a network at %jd\n", network_index);
+
+ // Fetch the network object
+ r = loc_database_fetch_network(e->db, network,
+ &e->network_address, node->depth, network_index);
+
+ // Break on any errors
+ if (r)
+ return r;
+
+ // Check if we are interested in this network
+
+ // Skip if the country code does not match
+ if (e->country_code && !loc_network_match_country_code(*network, e->country_code)) {
+ loc_network_unref(*network);
+ continue;
+ }
+
+ return 0;
+ }
+ }
+
+ // Reached the end of the search
+ // TODO cleanup
+
+ return 0;
+}
+
+LOC_EXPORT struct loc_network* loc_database_enumerator_next_network(
+ struct loc_database_enumerator* enumerator) {
+ struct loc_network* network = NULL;
+
+ int r = loc_database_enumerator_network_depth_first_search(enumerator, &network);
+ if (r) {
+ return NULL;
+ }
+
+ return network;
+}