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Armin Rigoa871ef22006-02-08 12:53:56 +00001/* "Rotating trees" (Armin Rigo)
2 *
3 * Google "splay trees" for the general idea.
4 *
5 * It's a dict-like data structure that works best when accesses are not
6 * random, but follow a strong pattern. The one implemented here is for
Thomas Wouters477c8d52006-05-27 19:21:47 +00007 * access patterns where the same small set of keys is looked up over
Armin Rigoa871ef22006-02-08 12:53:56 +00008 * and over again, and this set of keys evolves slowly over time.
9 */
10
11#include <stdlib.h>
12
13#define EMPTY_ROTATING_TREE ((rotating_node_t *)NULL)
14
15typedef struct rotating_node_s rotating_node_t;
16typedef int (*rotating_tree_enum_fn) (rotating_node_t *node, void *arg);
17
18struct rotating_node_s {
19 void *key;
20 rotating_node_t *left;
21 rotating_node_t *right;
22};
23
24void RotatingTree_Add(rotating_node_t **root, rotating_node_t *node);
25rotating_node_t* RotatingTree_Get(rotating_node_t **root, void *key);
26int RotatingTree_Enum(rotating_node_t *root, rotating_tree_enum_fn enumfn,
27 void *arg);