#ifndef _LINK_H#  define _LINK_Htypedef struct link_node{  // data  void *data;  // attributions  int type;  // relationship  //struct link_node *head;  struct link_node *next;  struct link_node *prev;  void (*destroy_data) (void *);  void (*dump_self) (void *);} link_node_t;typedef link_node_t link_t;#  if 0struct tree_node{  void *data;  struct tree_node *root;  struct tree_node *children;  struct tree_node *prev_brother;}#  endiftypedef enum insert_method{  INSERT_METHOD_BEFORE = 0,  INSERT_METHOD_AFTER = 1,} insert_method_t;typedef enum node_type{  NODE_TYPE_UNKNOWN = -1,  NODE_TYPE_HEAD = 100,  NODE_TYPE_NORMAL = 200,  NODE_TYPE_TAIL = 300} node_type_t;link_node_t *link_init(void (*destroy_data_callback) (void *), void (*dump_self_callback) (void *));void link_destroy(link_node_t * head);int link_insert_node(link_node_t * head, link_node_t * ref, link_node_t * p, insert_method_t method);int link_insert_normal_node(link_node_t * head, link_node_t * ref, link_node_t * p, insert_method_t method);int link_delete_node(link_node_t * head, link_node_t * p);link_node_t *create_node(node_type_t t);inline node_type_t get_node_type(link_node_t * p);link_node_t *link_locate_node(link_node_t * head, void *condition);int link_update_node(link_node_t * head, link_node_t * p);void link_dump_nodes(link_node_t * head);#endif