+int past_request_compare(past_request_t *a, past_request_t *b)
+{
+cp
+ return strcmp(a->request, b->request);
+}
+
+void free_past_request(past_request_t *r)
+{
+cp
+ if(r->request)
+ free(r->request);
+ free(r);
+cp
+}
+
+void init_requests(void)
+{
+cp
+ past_request_tree = avl_alloc_tree((avl_compare_t)past_request_compare, (avl_action_t)free_past_request);
+cp
+}
+
+void exit_requests(void)
+{
+cp
+ avl_delete_tree(past_request_tree);
+cp
+}
+
+int seen_request(char *request)
+{
+ past_request_t p, *new;
+cp
+ p.request = request;
+
+ if(avl_search(past_request_tree, &p))
+ {
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ syslog(LOG_DEBUG, _("Already seen request"));
+ return 1;
+ }
+ else
+ {
+ new = (past_request_t *)xmalloc(sizeof(*new));
+ new->request = xstrdup(request);
+ new->firstseen = now;
+ avl_insert(past_request_tree, new);
+ return 0;
+ }
+cp
+}
+
+void age_past_requests(void)
+{
+ avl_node_t *node, *next;
+ past_request_t *p;
+ int left = 0, deleted = 0;
+cp
+ for(node = past_request_tree->head; node; node = next)
+ {
+ next = node->next;
+ p = (past_request_t *)node->data;
+ if(p->firstseen + pingtimeout < now)
+ avl_delete_node(past_request_tree, node), deleted++;
+ else
+ left++;
+ }
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS && left + deleted)
+ syslog(LOG_DEBUG, _("Aging past requests: deleted %d, left %d\n"), deleted, left);
+cp
+}
+