| /* "Rotating trees" (Armin Rigo) | 
 |  * | 
 |  * Google "splay trees" for the general idea. | 
 |  * | 
 |  * It's a dict-like data structure that works best when accesses are not | 
 |  * random, but follow a strong pattern.  The one implemented here is for | 
 |  * accesses patterns where the same small set of keys is looked up over | 
 |  * and over again, and this set of keys evolves slowly over time. | 
 |  */ | 
 |  | 
 | #include <stdlib.h> | 
 |  | 
 | #define EMPTY_ROTATING_TREE       ((rotating_node_t *)NULL) | 
 |  | 
 | typedef struct rotating_node_s rotating_node_t; | 
 | typedef int (*rotating_tree_enum_fn) (rotating_node_t *node, void *arg); | 
 |  | 
 | struct rotating_node_s { | 
 | 	void *key; | 
 | 	rotating_node_t *left; | 
 | 	rotating_node_t *right; | 
 | }; | 
 |  | 
 | void RotatingTree_Add(rotating_node_t **root, rotating_node_t *node); | 
 | rotating_node_t* RotatingTree_Get(rotating_node_t **root, void *key); | 
 | int RotatingTree_Enum(rotating_node_t *root, rotating_tree_enum_fn enumfn, | 
 | 		      void *arg); |