return new;
}
+
+// Terminate circular list for traversal in either direction. Returns end *.
+void *dlist_terminate(void *list)
+{
+ struct double_list *end = list;
+
+ if (!list) return 0;
+
+ end = end->prev;
+ end->next->prev = 0;
+ end->next = 0;
+
+ return end;
+}
+
+// Find num in cache
+struct num_cache *get_num_cache(struct num_cache *cache, long long num)
+{
+ while (cache) {
+ if (num==cache->num) return cache;
+ cache = cache->next;
+ }
+
+ return 0;
+}
+
+// Uniquely add num+data to cache. Updates *cache, returns pointer to existing
+// entry if it was already there.
+struct num_cache *add_num_cache(struct num_cache **cache, long long num,
+ void *data, int len)
+{
+ struct num_cache *old = get_num_cache(*cache, num);
+
+ if (old) return old;
+
+ old = xzalloc(sizeof(struct num_cache)+len);
+ old->next = *cache;
+ old->num = num;
+ memcpy(old->data, data, len);
+ *cache = old;
+
+ return 0;
+}